Abstract
Istanbul, January 21–25, 2013
A Crosby, E Soon, F Jones, M Southwood, L Haghighat, M Toshner, ML Ormiston, DW Dunne, NW Morrell
Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom; Department of Pathology, University of Cambridge, Cambridge, United Kingdom; Department of Pathology, Papworth Hospital, Cambridge, United Kingdom.
Address correspondence to Alexi Crosby; e-mail:
Schistosomiasis is the worldwide leading cause of pulmonary arterial hypertension (PAH). More than 80% of patients with heritable PAH have a mutation in bone morphogenetic protein type-II receptor (BMPR-II), a receptor for ligands of the transforming growth receptor-beta (TGF-β) superfamily. The aim of the study is to determine if mice with a heterozygous null mutation in BMPR-II (MUT) are more susceptible to schistosomiasis-induced PAH, compared to wild-type (WT) littermates and to see if bone marrow–derived cells contribute to pulmonary vascular remodeling. To this end, WT and MUT mice were infected percutaneously with Schistosoma mansoni. At 17 weeks postinfection, right ventricular systolic pressure (RVSP), right ventricular (RV) hypertrophy, liver and lung egg counts, and body weight were measured. Pulmonary vascular remodeling was assessed by morphometry, following immunohistochemistry. Additionally, lung, liver, and serum cytokines were measured. The capacity of bone marrow–derived (BMD) macrophages from WT and MUT mice to phagocytose fluorescently labeled beads was assessed. In addition, mice were lethally bone marrow–irradiated, transplanted (BMT) with bone marrow from GFP-expressing WT mice, and then infected with S. mansoni. The contribution of GFP-expressing BMD cells to vascular remodeling and the number of circulating BMD fibrocytes were measured. At 17 weeks postinfection there was no significant difference in RVSP, RV hypertrophy, or liver weight between WT and MUT mice. However, there was a significant reduction in body weight and a significant increase in lung egg deposition and lung cytokine expression in the MUT mice, compared to WT mice. There was no significant difference in serum cytokine levels. We saw a profound degree of pulmonary vascular remodeling in all animals. In BMT animals, both granulomas and remodeled vessels in the lung were surrounded by a high proportion of BMD GFP-expressing cells. There was also a significant increase in circulating fibrocytes in infected mice. In conclusion, this study has shown that BMPR-II mutations do not predispose to schistosomiasis-induced PAH but that there is either an increased ability of the eggs to gain access into the lungs or a decrease in egg clearance from the lungs. This in turn leads to a heightened inflammatory response in the lungs of these mice. We have also shown that BMD cells play an important role in the inflammatory response and pulmonary vascular remodeling seen in this mouse model.
Y Li,1 X-H Li2
1 Third Xiangya Hospital, Central South University, Changsha, China; 2 Department of Pharmacology, School of Pharmaceutical Science, Changsha, China
Address correspondence to Xiao-Hui Li; e-mail:
Iron supplement is efficient to inhibit the increase of pulmonary arterial systolic pressure (PASP) induced by hypoxia. Recently, iron deficiency is normally observed in idiopathic pulmonary arterial hypertension (IPAH) patients, while the situation of iron metabolism and its regulatory mechanism under hypoxic pulmonary hypertension (HPH) are seldom known. HPH rats were induced by 4 weeks of hypoxia. Besides regular blood tests, blood samples were collected for determination of several factors related to iron metabolism, including iron, ferritin, transferritin, and hepcidin, which is synthesized in the liver and plays a key role in inhibiting iron absorption, release, and storage. Furthermore, RNA and protein were extracted from liver tissues to evaluate the transcriptional level of hepcidin and protein expression of the upstream regulator of hepcidin, BMP6. The results showed that iron concentration (12.5 ± 2.41 vs. 5.78 ± 2.86, P = 0.033) was significantly decreased in HPH rats, while the plasma levels of transferritin (1.6 ± 0.59 vs. 5.78 ± 2.86, P = 0.012) and hepcidin (1.6 ± 0.59 vs. 5.78 ± 2.86, P = 0.048) were increased. The plasma level of ferritin was also decreased, but the change is not significant (1.6 ± 0.59 vs. 5.78 ± 2.86, P = 0.051). Regular blood tests showed that WBC (1.6 ± 0.59 vs. 5.78 ± 2.86, P = 0.013) and MCV (57.58 ± 2.39 vs. 61.28 ± 2.01, P = 0.029) were decreased in HPH rats. Q-PCR and Western blot experiments showed that hepcidin mRNA level and BMP6 protein level were both significantly increased in liver. In conclusion, the disorder of iron metabolism generally exists in HPH rats, and an upregulated BMP6/hepcidin signaling pathway in liver may contribute to this progress.
G Mohd
SNM Hospital, Leh, Ladakh, India
E-mail:
Pulmonary arterial systolic pressure (PASP) was measured in 90 patients with high-altitude pulmonary edema (HAPE) by echocardiogram. The aim and objective of the study was to find the importance of measurement of PASP in cases of HAPE and to correlate it with other parameters. It was found that PASP invariably increases to a mean level of 47.70 mmHg. The rise of PASP is directly related to the severity of fall of oxygen and does not correlate directly to the severity of grade of pulmonary edema. PASP study in HAPE cases makes it possible to understand complicated cases of HAPE, as in cases of pulmonary thrombus formation in situ in pulmonary arteries the rise of PASP is severe, as compared to the general cases, and the fall of the pressure is also relatively slow in the course of the disease. The rise of PASP at high altitude is a common phenomenon, as sometimes attendants can have higher PASP without symptoms than the patient. A high PASP in a HAPE case, especially in a young patient, is associated with angina-like chest pain, which seems to be due to stretching of the pulmonary arterial trunk due to a high rise in pulmonary pressure. A high rise in PASP may not take more than 12 hours to fall by half the pressure if provided with oxygen. PASP measurement seems to be an important parameter in prognostication of the patient, as an expected fall of the pressure with the duration of time means a normal-behaving patient rather than a patient with slow, persistent rise of PASP.
H Banjar
Department of Paediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
E-mail:
The objective is to identify the different congenital anomalies that are associated with PH in cases referred to the paediatric pulmonary clinic in a tertiary care center in Saudi Arabia. Methods included a retrospective chart review of all patients referred to the pulmonary clinic with documented pulmonary hypertension based on cardiac catheterization and/or echocardiogram during an 11-year period between January 2001 and December 2011. The results were a total of 200 patients with confirmed pulmonary hypertension (PH), with a mean age at diagnosis of 3.2 years. 191 patients had PH and associated disease (95.5%), and 9 patients (4.5%) had idiopathic PH. 58 patients (29%) were diagnosed with Down syndrome and congenital heart disease. 28 patients (14%) had chromosomal abnormalities and dysmorphology, such as CHARGE association, skeletal dysplasia, and central nervous system anomalies. 20 patients (10%) had congenital lung anomalies, such as lung hypoplasia, congenital lobar emphysema, and diaphragmatic hernia. 40 patients (20%) were diagnosed with lung diseases and hypoxia. Gastrointestinal anomalies were detected in 8 patients (4%) and other anomalies in 37 patients (19%), such as renal anomalies, malignancies, and other diseases. Our conclusion is that congenital anomalies are a common association in patients with pulmonary hypertension. Recent classification should include congenital anomalies as part of the classification of pediatric pulmonary hypertensive vascular disease.
N Goncharova, O Moiseeva
Noncoronary Disease Department, Almazov Federal Center of Heart, Blood and Endocrinology, Saint Petersburg, Russia
Address correspondence to Natalia Goncharova; e-mail:
The objective of this study is to describe survival in adult Eisenmenger Syndrome (ES) patients and to investigate noninvasive risk factors for mortality. Methods centered on including all consecutive patients with ES seen between September 2008 and July 2012 in a single high-volume cardiosurgery center. All causes of mortality were assessed. The observed survival was estimated with Kaplan-Meier survival curves. Data including symptoms, functional class, 6MWT, medication, laboratory, and electrocardiographic and echocardiographic parameters were included in univariate and subsequent multivariate Cox proportional-hazards analysis. Our results were as follows: 53 patients were enrolled between 34 ± 13.7 years of age. Overall, 90.7% of patients were younger than 50 years, and only 13 of 53 patients were male. The mean age was 33.5 ± 14.6 years for women and 36.6 ± 11.4 years for men. The main underlying diagnosis was ventricular septal defect (VSD; N = 23, 43.4%), followed by complex congenital heart defect (N = 11, 20.7%), atrial septal defect and partial anomalous venous drainage (16.9%, N = 6 and 3, respectively), atrioventricular septal defect (N = 6, 11.3%), and persistent arterial duct (PAD; N = 4, 7.5%). Mean oxygen saturation at rest was 85.5% ± 7%. On admission, 50% of patients were in NYHA FC III or IV. 11 patients (20.7%) received PAH-specific therapy with sildenafil; the majority of them were FC III–IV patients (N = 9). The remaining 66.6% of FC III–IV patients did not get PAH-specific therapy due to financial reasons. 7 patients (12.9%) died during the mean follow-up time of 1.3 ± 1 years (range: 30–1,530 days). The observed 1- and 3-year survival rates were 92% and 68%, respectively. No difference in mortality rates between incident (46.3% patients) and prevalent groups was revealed. On univariate Cox regression analysis, syncope presence (P = 0.05), high Nt-proBNP (≥1,017 pg/mL), uric acid, INR, and hematocrit levels were all associated with an increased risk of death (P = 0.02, P < 0.01, P = 0.03, and P = 0.04, respectively). On multivariate analysis, only elevated uric acid concentration remained an independent predictor of death. Kaplan-Meier survival curves based on median serum uric acid concentration (389 mmol/L) showed that patients with higher values had a significantly worse 1- and 3-year survival rates (93% vs. 100% and 56% vs. 100%, respectively) than those with low values (log-rank test: P = 0.02). No correlation was observed between survival and PAH-specific therapy presence. The study's conclusion is that a steep decline in the 3-year survival curve could be attributed to a large proportion of FC III–IV patients, in comparison with other registries, and the lack of PAH-specific therapy. Serum uric acid measurement can be performed inexpensively and repeatedly as a predictor of mortality in the long-term follow up of adult patients with Eisenmenger syndrome.
F Harel, X Levac, QT Nguyen, M Letourneau, S Marcil, V Finnerty, A Fournier, J Dupuis
Research Center, Montreal Heart Institute, Montreal, Quebec, Canada;
Institut National de la Recherche Scientifique (INRS)-Institut Armand Frappier, Laval, Quebec, Canada
Address correspondence to Dr. Jocelyn Dupuis; e-mail:
PulmoBind is a novel radiopharmaceutical agent developed for the noninvasive evaluation of pulmonary hypertension (PH). It is a chelated derivative of human adrenomedullin labeled with 99m-Tc for nuclear medicine SPECT imaging. By specifically binding to its pulmonary endothelial receptors, it allows quantification of perfusion defects and can detect PH in animal models. PulmoBind has not yet been tested in humans. For our study, healthy human volunteers (n = 20) were included in this phase I trial (NCT01539889; http://www.clinicaltrials.gov). They were administered a dose of 5 mCi (n = 5), 10 mCi (n = 5), or 15 mCi (n = 10) of 99m-Tc-PulmoBind, and vital signs were closely monitored. Any local or systemic reaction was monitored, and safety biochemistry and hematology parameters were evaluated. Nuclear medicine imaging was performed, and radioactive waste was collected for dosimetric analysis. Our results showed that radiochemical purity of 99m-Tc-labeled PulmoBind was greater than 95%. The product was well tolerated, and there were no safety concerns at the 3 dosages studied. There were no significant hemodynamic effects of PulmoBind. Imaging revealed predominant lung uptake. Mean peak pulmonary extraction of PulmoBind was 58% ± 7% of the injected dose. Mean extraction 35 minutes after injection was 44% ± 6%. Pulmonary activity was still substantial after 60 minutes with one-third of the injected dose: 33% ± 5%. Tomographic images were of good quality, and the physiological postural lung perfusion gradient was easily detected. The dosimetric profile revealed that the tracer was eliminated mostly in urine. In conclusion, PulmoBind injection is safe and can be used for molecular imaging of the human pulmonary circulation. This agent may be useful in the noninvasive diagnosis and follow-up of pulmonary hypertension.
J Huang, MH Gewitz, R Mathew
Section of Pediatric Cardiology, Maria Fareri Children's Hospital, New York Medical College, Valhalla, New York, USA
Address correspondence to Rajamma Mathew; e-mail:
Proinflammatory cytokine IL-6 is reported to be increased in pulmonary hypertension (PH) irrespective of the underlying disease, and it negatively impacts prognosis. IL-6 activation stimulates the gp130/JAK pathway leading to the activation of PY-STAT3, a proliferative transcription factor. Caveolin-1 (cav-1) suppresses PY-STAT3 activation. Cav-1, a 22-kDa protein, is the major resident scaffolding protein constituent of caveolae in plasma membrane of a variety of cells, including endothelial cells (EC) and smooth muscle cells (SMC). Cav-1 inhibits cell proliferation, participates in apoptosis, and functions as an immunomodulator. However, increased cav-1 expression in SMC in PH loses its inhibitory capacity and actively participates in cell proliferation. We have recently reported loss of endothelial cav-1 coupled with enhanced expression of cav-1 in pulmonary artery SMC, with subsequent neointima formation in a child with PH. Monocrotaline (MCT)-induced PH is associated with an early and progressive IL-6 mRNA upregulation, increased IL-6 bioactivity, loss of endothelial cav-1, and PY-STAT3 activation. Anti-inflammatory treatment instituted early inhibits IL-6 upregulation, rescues caveolin-1, inhibits PY-STAT3 activation, and attenuates PH. Our main aim was to investigate whether inflammation and/or cav-1 played a role in hypoxia-induced PH in rats and to compare with the MCT model. Male Sprague-Dawley rats were subjected to hypobaric hypoxia or were given MCT (60 mg/kg, sc). Hemodynamic data and the expression of cav-1, gp130, PY-STAT3, eNOS, and pVASP in the lungs were examined at 48 hours and 1, 2 and 4 weeks. Progressive PH and RVH were observed in both models. PY-STAT3 activation occurred before the onset of PH in both models. The MCT model revealed progressive loss of endothelial cav-1. Importantly, 23% of the arteries with extensive loss of endothelial cav-1 revealed enhanced expression of cav-1 in SMC at 4 weeks, but none did at 2 weeks. In contrast, hypoxia-induced PH did not exhibit loss of endothelial cav-1 or enhanced expression of cav-1 in SMC. In the MCT model, eNOS expression was progressively reduced, but there was no loss of eNOS in the hypoxia model. However, there was evidence of impaired eNOS function in both. In conclusion, both models exhibit progressive PH, activation of proliferative and antiapoptotic pathways, and impaired eNOS function. MCT-induced PH is associated with progressive loss of endothelial cav-1. PY-STAT3 activation occurred in the hypoxia model without concomitant loss of cav-1, indicative of cav-1 dysfunction. Thus, the loss or dysfunction of endothelial cav-1 promotes inflammation and cell proliferation, contributing to PH. The differences in the status of endothelial cav-1 and subsequent enhanced expression of cav-1 in SMC may determine the irreversibility versus reversibility in PH.
H Tsang,D Dalgalan,L Howard,J Wharton,D Lane,J Ahnstrom,MR Wilkins,B Wojciak-Stothard
Centre for Pharmacology and Therapeutics, Imperial College London, London, United Kingdom; National Pulmonary Hypertension Service, Imperial College Healthcare National Health Service Trust, London, United Kingdom; Department of Haematology, Imperial College London, London, United Kingdom
Address correspondence to B. Wojciak-Stothard; e-mail:
Chronic thromboembolic pulmonary hypertension (CTEPH) results from obstruction of the pulmonary vascular bed by nonresolving thromboemboli, leading to remodeling of the pulmonary vessel wall, obstructive plexiform lesions, multifocal thrombosis, and enhanced vasoconstriction. Increased levels of plasma microparticles (MPs) and membrane vesicles <1 μm released after cell activation or apoptosis are reported in several cardiovascular disorders, related to severity. We hypothesized that patients with chronic thromboembolic pulmonary hypertension (CTEPH) will show increased levels of plasma microparticles and that microparticles from CTEPH patients will induce pulmonary endothelial dysfunction in vitro. Microparticles from healthy volunteers and patients with pulmonary embolism or CTEPH (n = 6/group) were isolated by sequential centrifugation, and the purity of the MP fraction was confirmed by flow cytometry, light-scattering spectrophotometry, and electron scanning microscopy. MPs were incubated with human pulmonary artery endothelial cells, and their effects on cell proliferation, angiogenesis, inflammatory cytokine release, leukocyte adhesion, and thrombin generation were studied. Patients with CTEPH showed increased overall levels of MPs and increased levels of MPs of endothelial origin in blood, as compared to patients with pulmonary embolism (PE) or healthy volunteers. MPs from CTEPH patients increased cell metabolic activity and stimulated endothelial tube formation in vitro, while MPs from healthy volunteers had no effect. CTEPH MPs had the strongest stimulatory effect on leukocyte adhesion and transmigration through pulmonary endothelium. Preliminary analysis of proinflammatory cytokine release revealed increased production of proinflammatory cytokines induced by MPs from CTEPH patients (CD40, sICAM-1, IL-4, IL-5, IL-6, IL-13, C5/C5a, and CCL-2). MPs from CTEPH patients showed reduced procoagulant properties, as compared with other study groups. In conclusion, CTEPH patients show increased levels of circulating MPs, which induce pulmonary endothelial dysfunction in vitro.
VB Abdul-Salam, M Gierula, RJ Edwards, L Zhao, MR Wilkins, B Wojciak-Stothard
Centre for Pharmacology and Therapeutics, Experimental Medicine, Imperial College London, London, United Kingdom
Address correspondence to B. Wojciak-Stothard; e-mail:
Inflammation plays an important role in the pathogenesis of pulmonary arterial hypertension (PAH). Our recent data show increased expression of chloride intercellular channel-4 (CLIC4) in pulmonary artery endothelial cells of the remodeled pulmonary vasculature of PAH patients and rats with monocrotaline-induced PH. CLIC4 contributes to several of the pathways implicated in the regulation of inflammatory responses and the pathogenesis of PAH, including Rho, VEGF, bone morphogenetic protein (BMP), and TGF-β and TNF-α signaling. In this study, we investigated the role of CLIC4 in the regulation of inflammatory responses in human pulmonary artery endothelial cells (HPAECs). Expression levels of CLIC4 in HPAECs were modulated using adenoviral overexpression of CLIC4 or CLIC4 shRNA. Label-free proteomics and pathway analysis were used to identify proteins affected by overexpression of CLIC4. Inflammatory cytokine microarray, NFkB luciferase reporter assay, and leukocyte adhesion and transmigration assays were used to study inflammatory responses in HPAECs. HPAECs showed increased expression of proinflammatory proteins associated with NFkB signaling, including AMP deaminase-3, chondroitin sulfate proteoglycan-4, insulin receptor substrate-1, and kindlin-3. Overexpression of CLIC4 significantly increased the activity of NFkB in HPAECs (8-fold increase, P < 0.001, n = 12/group) and increased the release of proinflammatory cytokines, including RANTES and complement 5. These effects were prevented by CLIC4 shRNA. CLIC4 overexpression significantly increased leukocyte adherence and chemotaxis (P < 0.05 and P < 0.001, respectively), while CLIC4 shRNA and function-blocking anti-RANTES antibodies had an inhibitory effect (P < 0.001). In conclusion, CLIC4 induces inflammatory activation of human pulmonary endothelial cells. Modulation of CLIC4 expression may offer a novel therapeutic target in PAH.
M alDabbagh
King Fahd Armed Forces Hospital, Jeddah, Saudi Arabia
E-mail:
The objective is to assess the presurgical patient preparation and evaluation of pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) in children and adolescents from the perspective of the pulmonologist, to minimize risk factors. To this end, a prospective multicenter surveillance was carried out, where pediatric pulmonologists were asked to establish the minimal presurgical requirements and the current practice in different centers. Currently, all patients are evaluated according to special protocol in each center, with special attention to Down Syndrome cases. Full analysis is ongoing, and results will follow.
VD Aiello, L Halluli, AA Lopes
Laboratory of Pathology; Clinical Division of Paediatric Cardiology and Adult Congenital Heart Disease–Heart Institute (InCor) of São Paulo University Medical School, São Paulo, Brazil
Address correspondence to Vera Demarchi Aiello; e-mail:
Patients with congenital cardiovascular shunts may develop pulmonary hypertension (PH) if not submitted to corrective or palliative surgery early in life. In developing countries, the occurrence of PH in such contexts is more prevalent that in the developed world. Lung biopsy in selected cases can help us to understand the evolution and guide the management of the pulmonary vascular disease in such patients. Histological data were retrieved from 124 lung biopsies received over a period of 15 years at the Pathology Laboratory of the Heart Institute (InCor) of São Paulo University Medical School for evaluation of the histological lesions of patients with PH associated with congenital heart defects (mean age: 45.1 months; median age: 15.5 months; 55% females). The lung fragments were collected inflated, either pre- or intraoperatively. The histological analysis included the determination of the qualitative degree of pulmonary vascular disease (Heath-Edwards system) and the morphometric approach (Rabinovitch-Haworth system) whenever the lung fragments were adequate in terms of inflation and in the absence of hemorrhage. Results showed that isolated hypertrophy of the medial layer of arteries (Heath-Edwards grade I) was present in 30.6% of the biopsies (mean age: 26.3 months); noncompletely occlusive intimal proliferation (Heath-Edwards grade II) was found in 40.3% of the cases (mean age: 43.3 months); completely occlusive, plexiform, and angiomatoid lesions (Heath-Edwards III, IV, and V) were present in 26.6% of the biopsies (mean age: 86.6 months). In 3 patients (2.4%; mean age: 14.4 months), no histological signs of vascular disease were found. Patients with irreversible qualitative lesions (Heath-Edwards III or higher) were significantly older when compared to those with Heath-Edwards grades I and II (P = 0.003). In cases with reversible qualitative lesions, the morphometric evaluation depicted grade B (increased medial thickness and normal alveolar/artery ratio for age) in 26% of the cases (mean age: 24.4 months) and grade C (increased alveolar/artery ratio) in 38.6% (mean age: 35.8 months). In the remaining cases, the morphometric analysis was not feasible. In conclusion, most of the biopsies analyzed showed reversible vascular lesions from the qualitative point of view. However, the morphometric evaluation allowed the recognition of decreased numerical development of distal arteries (grade C) in more than one-third of patients with qualitative lesions considered as reversible. Of notice, most biopsy specimens were collected intraoperatively, by the time of repair of the cardiac anomaly. In patients with less severe hemodynamic abnormalities who were discharged from hospital under the assumption that “the treatment was successful” and “the disease is cured,” findings from direct examination of pulmonary arteries—for example, noncompletely occlusive intimal proliferation, localized occlusive lesions, or a morphometric grade C—may be the signature of a silent disease that will (or will not) become manifest in the future. Having this possibility in mind may be of help in planning an adequate assistance during the follow-up, so that a residual disease can be promptly detected (if existent) and properly managed. Thus, we firmly believe that the systematic analysis of lung biopsies can provide important information in a selected group of patients with PH secondary to congenital heart defects.
M Taha, Y Deng, DJ Dumont, DJ Stewart
Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Molecular and Cellular Biology Research, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
Address correspondence to Mohamad Taha; e-mail:
Pulmonary arterial hypertension (PAH) is characterized by degradation and remodeling of the pulmonary vasculature, leading to increased pulmonary vascular resistance. Consequently, patients with PAH develop right ventricle hypertrophy and ultimately heart failure and death. Pulmonary endothelial cell (EC) apoptosis is believed to trigger PAH by inducing reactive vascular inflammation and cell proliferation, leading to obliterative distal arteriolar remodeling. An emerging preclinical model of PAH includes induction of lung EC apoptosis by inhibition of VEGFR2 with SU5416 (SU), combined with chronic hypoxia (CH), leading to severe, irreversible PAH in rats, characterized by occlusive intimal lesions, similar to plexiform lesions in human PAH. In contrast, mice are relatively resistant to SU+CH-induced PAH, even with multiple injections. Tie2 represents another major EC survival signaling pathway, and Tie2 heterozygous knockout mice have been reported to be susceptible to lung EC apoptosis and PAH. We hypothesized that, compared to WT mice, Tie2-deficient mice will exhibit greater EC apoptosis, more vascular remodeling, and marked PAH in response to SU+CH, thus providing a better murine model of severe, irreversible PAH. To this end, wild-type or Tie2 heterozygous mice (Tie2+/) were exposed to normoxia or 3 weeks of CH (9%-10% O2), combined with one or more subcutaneous injections of SU (20–50 mg/kg). Right ventricle systolic pressure (RVSP) and the ratio of RV over left ventricular plus septal weight (RV/LV + septum) were determined at 3 weeks. This resulted in both WT and Tie2+/– mice demonstrating identical increases in (RVSP) and right ventricular (RV) remodeling when exposed to CH for 3 weeks, compared to normoxia controls. There was no further increase in RVSP in WT mice exposed to SU+CH, compared to CH alone, even with multiple injections (up to 6) and high doses (50 mg/kg). However, even a single injection of SU significantly increased RVSP in CH Tie2+/–mice, compared to WT littermates exposed to the same conditions (42 ± 1.3 vs. 35 ± 1.6 mmHg, respectively; n = 914/group; P < 0.01), with significantly greater RV remodeling (RV/LV + S = 0.49 ± 0.01 for SU+CH Tie2+/– mice vs. 0.44 ± 0.01 for SU + CH WT mice, n = 1015; P < 0.05). Histological assessment of lung sections of treated animals did not reveal any plexiform-like lesions at 3 weeks; however, there was an increase in apoptosis (P = 0.05) in the lungs of the Tie2+/– mice compared to CH-only-treated controls at 3 weeks. In conclusion, Tie2-deficiency provides a “second hit” when combined with VEGFR2 inhibition and predisposes to severe PAH together with CH. SU+CH in a Tie2-deficient background may provide a robust murine model of severe PAH.
V Samillan, T Haider, J Vogel, C Leuenberger, M Brock, C Schwarzwald, M Gassmann, L Østergaard
Institute of Veterinary Physiology, University of Zürich, Zurich, Switzerland; Institute of Human Movement Sciences and Sport, ETH Zürich, Zurich, Switzerland; Zürich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland; Pulmonary Hypertension Working Group, University Hospital Zürich, Zurich, Switzerland; Equine Department, University of Zürich, Zurich, Switzerland
Address correspondence to Louise Østergaard; e-mail:
Pulmonary hypertension is an incurable disease that often leads to right ventricular hypertrophy and right heart failure. The present study investigated single versus combined therapy with sildenafil and erythropoietin on hypoxia-induced pulmonary hypertension. Mice were randomized into 5 different groups and exposed to either hypoxia (10% oxygen) or normoxia for totally 5 weeks. Hypoxic mice were treated with either saline solution, erythropoietin (500 IU/kg, 3 times weekly), sildenafil (10 mg/kg, daily), or the combination of both drugs for the last 2 weeks of hypoxic exposure. We measured pulmonary pressure using right heart catheterization, and the ventilator response to hypoxia was recorded via whole-body plethysmography. Immunohistochemistry was performed to elucidate changes of pulmonary morphology and of right heart hypertrophy. Plasma levels of cardiotrophin-1 and atrial natriuretic peptide were quantified. Treatment with either erythropoietin or sildenafil alone lowered the hypoxia-induced increase of pulmonary pressure and reduced pulmonary edema formation, pulmonary vascular remodeling, and right ventricular hypertrophy. Notably, the combination of both drugs had the most prominent effect. Changes in cardiotrophin-1 and ANP levels confirmed these observations. In conclusion, the combination treatment with erythropoietin and sildenafil demonstrated an improvement in the clinical outcome in hypoxia-induced PH in mice that was superior to that observed for either drug given alone.
Y-J Lai,1, W-J Chen2
1 Department of Respiratory Therapy, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; 2 First Cardiovascular Division, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan
Address correspondence to Wei-Jan Chen; e-mail:
Pulmonary arterial hypertension (PAH) is characterized by increased small pulmonary vascular resistance and is caused by increased migration and proliferation of pulmonary arterial smooth muscle cells (PASMC). Propylthiouracil (PTU), an antithyroid drug, has clinical implications in treating hyperthyroidism. Results in our laboratory show that PTU inhibits the development of atherogenesis. PTU acts through the induction of PTEN, a tumor suppressor gene, to inhibit vascular smooth muscle cell (VSMC) proliferation and migration. Interestingly, one study shows that PTU has an inhibitory effect on PAH development. The mechanisms underlying the suppressive effects of PTU on PAH, however, remain to be clarified. Because PAH is characterized by the increased migration and proliferation of PASMCs, this proposal addresses the hypothesis that PTU inhibits the progress of vascular remodeling through PTEN signaling pathways in the PASMC proliferation and migration. We established the rat model of monocrotaline (MCT)-induced pulmonary arterial hypertension (MCT-PAH). Right ventricle systolic pressure (RVSP) was increased significantly in the MCT-PAH group, as compared with the control group. 14 days after MCT was injected, PTU was applied from day 14 to 28, resulting in significantly decreased RVSP. We then quantitatively measured the degree of muscularization of pulmonary arteries within a-sm-actin immuohistochemistry (IHC) in the lung sections. Treatment with PTU resulted in a significant reduction in medial wall thickness of pulmonary arteries, as compared with the MCT 28-day group. In addition, the IHC was utilized to detect PTEN in the MCT-PAH rat lung sections and demonstrated that the expression of PTEN is increased by treatment with PTU in the MCT-PAH rats. To gain detailed information of PTU effects at the cellular and molecular levels, we observed PASMC isolated from the MCT-PAH rats. Here, we show that PTU inhibits PASMC proliferation in a dose-dependent manner and suppresses cell nuclear antigen (PCNA) translocation from the cytoplasm into the nucleus. Furthermore, treatment of PTU increased the PTEN mRNA in a dose-dependent manner. These studies may provide a deeper understanding about the pathogenesis of PAH. In addition, the results may help to define the role of PTU/PTEN in preventing progressive and fatal PAH and may provide new approaches for therapeutic intervention in PAH.
SSB Raj, GS Ajithkumar, S Santhoshkumar, CC Kartha
Cardiovascular Disease Biology Division and Animal Research Facility, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
Address correspondence to C. C. Kartha; e-mail:
Pulmonary hypertension associated with left heart disease (PH-LHD) represents the most common form of PH and is characterized by lung endothelial dysfunction and vascular remodeling. 68%–76% of patients with LHD have PH, which serves as an independent predictor of morbidity and mortality in heart failure. Left ventricular or valvular disease results in passive backward transmission of elevated left atrial pressure and partial obstruction to pulmonary venous drainage. This hemodynamic disturbance in circulation causes increased shear stress and turbulent flow in pulmonary circulation. Vascular endothelium senses this hemodynamic stress acting on luminal surface by various mechanosensors. It initiates signals that adapt endothelium to its new environment by functional and structural changes in pulmonary vasculature. In LHD-induced pulmonary vascular remodeling there appears to be hemodynamic stress–induced endothelial dysfunction, leading to dysregulation of vasoactive mediators and growth factors. The mechanisms that lead to endothelial dysfunction during pulmonary vascular remodeling and associated PH, however, are unclear. A strong rationale exists for the study of mechanosensitive genes in pulmonary endothelial cells and how these factors affect endothelial function. In this study, we analyzed the level of expression of a shear-sensitive factor HuR, an ELAV-like protein, and its regulator molecules, such as Krüppel-like factor 2 (Klf 2), endothelial nitric oxide synthase (eNOS), and bone morphogenic protein 4 (BMP4), in a rat model of left heart failure. Left heart failure was induced in male Wistar rats by banding the ascending aorta. After 5 months of aortic banding, significant increases in heart weight–to–body weight ratio and left ventricle + septum weight–to–heart weight ratios were observed, indicating cardiac hypertrophy. In ventricular tissues of aortabanded rats, 5 months after surgery there was a shift from MYH6 (myosin heavy chain 6) to MYH7. Aortic banding produced an increase in right ventricular weight–to–body weight ratio, demonstrating right ventricular hypertrophy. Compared to sham-operated controls, an increase in pulmonary vascular wall thickness was observed in rats that had undergone aortic banding, representing pulmonary vascular remodeling. The aortic banding led to significant increase in pulmonary HuR mRNA levels. We also analyzed the HuR regulating anti-inflammatory and antiproliferative genes Klf2 and eNOS, as well as the proliferative gene BMP4, in lung tissue. We observed that Klf2 was downregulated, but there was no significant change in the expression of eNOS. BMP4 mRNA levels were also found to be increased. Our study reveals that LHD-associated hemodynamic stress in pulmonary circulation induces the activation of HuR and results in downstream dysregulation of various endothelial mediators. Downregulation of Klf 2 and upregulation of BMP4 could change the endothelium to an inflammatory and proliferatory phenotype during pulmonary vascular remodeling. Our results indicate a critical role for HuR in pulmonary vascular remodeling, secondary to left ventricular hypertrophy.
R Badagliacca, R Poscia, B Pezzuto, S Papa, M Nocioni, M Mezzapesa, F Fedele, CD Vizza
Department of Cardiovascular and Respiratory Science, University of Rome “Sapienza,” Rome, Italy
Address correspondence to Roberto Badagliacca; e-mail:
It is widely accepted that registries have the advantage of providing “real-life” information on the characteristics and management of pulmonary arterial hypertension (PAH) in clinical practice. In Italy, a common database among several referral centers for PAH (Rome, Pavia, Naples, Palermo, and Turin) has been developed in 2012 for clinical and scientific purposes (iPHNET: Italian Pulmonary Hypertension NETwork). The aim of our proposal is the creation of a common PVRI database to collect clinical evidence on the following issues: external validation of scores and formulas to predict prognosis; identify new prognostic factors; prevalence of different modalities of death; identify specific risk factors for different modalities of death. The iPHNET project database could be taken as a model for the PVRI database. The database is composed of two sections. The first, demographic and clinical section includes types of PH, comorbidities, WHO functional class, weight, height, and all physical examination parameters, whereas the second section includes all diagnostic procedures (ECG, 6-minute walk test, echocardiography, right heart catheterization, pulmonary function test, etc.) and blood samples (blood gases, neurohormones, etc.). The system allows physicians to easily extrapolate more parameters in different charts, making easier the identification of those patients with a higher risk of disease progression or inadequate response to therapy. All the data inserted from a single center can be easily extrapolated in Excel form for its own purposes or shared as a huge database recording the selected data from all users. It is important to underscore that the system is encrypted so that nobody (including the system administrator) has access to another center's data unless shared by the center itself. The database is also designed to help the centers in their daily activities, so it can easily produce a final report for a patient after collecting the data during the clinical visit. The database is built according to FDA CRF 21-Part 11. The regulations in this part set forth the criteria under which the agency considers electronic records, electronic signatures, and handwritten signatures executed to electronic records to be trustworthy, reliable, and generally equivalent to paper records and handwritten signatures executed on paper. FDA CRF 21-Part 11 applies to records in electronic form that are created, modified, maintained, archived, retrieved, or transmitted under any records requirements set forth in agency regulations. Where electronic signatures and their associated electronic records meet the requirements of this part, the regulatory agency will consider the electronic signatures to be equivalent to full handwritten signatures, initials, and other general signings as required by agency regulations. Electronic records that meet the requirements of this part may be used in place of paper records. Computer systems (including hardware and software), controls, and attendant documentation maintained under this part shall be readily available for and subject to FDA inspection. This is possible because the system that has been created allows people who use the database system to create, modify, maintain, or transmit electronic records with approved procedures and controls designed to ensure the authenticity, integrity, and, when appropriate, the confidentiality of electronic records. In conclusion, the application of this kind of database may allow PVRI members to collect multicenter data on relevant topics such as epidemiologic data, prognostic indicators, and therapeutic strategies; to assess the impact of changes on patient management while new drugs develop; and last but not least, may allow PVRI members to think about their own experience and practice performance. Additionally, every center may use the database for its daily clinical activities, as the system allows physicians to create a final report form for the patient.
KD Sagliani, RR Warburton, NS Hill, BL Fanburg, IZ Jaffe, IR Preston
Tupper Research Institute and Pulmonary, Critical Care and Sleep Division, Tufts University School of Medicine, Tufts Medical Center, Boston, Massachusetts, USA; and Molecular Cardiology Research Institute and Division of Cardiology, Tufts University School of Medicine, Tufts Medical Center, Boston, Massachusetts, USA
Address correspondence to Dr. Ioana Preston; e-mail:
The mineralocorticoid receptor (MR) contributes to systemic vascular remodeling. MR stimulated by aldosterone promotes systemic vascular smooth muscle cell (SMC) proliferation and fibrosis. We hypothesized that MR is also a contributor to the pulmonary vascular remodeling of experimental pulmonary hypertension (PH), a process that is characterized by medial thickening, in part due to SMC hyperplasia and hypertrophy. We tested the effects of the MR inhibitor spironolactone in chronic hypoxia-induced PH in mice and in monocrotaline-induced PH in rats. The biological function of the MR pathway was analyzed in cultured pulmonary artery SMCs. Our results were as follows. In the hypoxia-PH mouse model, spironolactone attenuated the increase in right ventricular systolic pressure, pulmonary arterial muscularization, and right ventricular fibrosis. In the prevention arm of monocrotaline-induced PH rat model, spironolactone significantly attenuated pulmonary vascular resistance and pulmonary vascular remodeling. In the established disease (treatment arm), MR antagonism decreased right ventricular systolic pressure and pulmonary vascular resistance, while there was no significant effect on pulmonary arterial muscularization. Right ventricular fibrosis was not significantly affected in this model. Spironolactone decreased cardiomyocyte size modestly and had no effect on right ventricular hypertrophy, systemic blood pressure, cardiac output, or body weight, suggesting a predominantly local effect on the pulmonary vasculature. In pulmonary artery SMCs, the MR agonist aldosterone stimulated proliferation. Hypoxia- and platelet-derived growth factor–induced proliferation was attenuated by spironolactone. In conclusion, we found that MR antagonism prevents pulmonary artery SMC proliferation and attenuates experimental PH. These data suggest that MR is involved in the pathogenesis of experimental PH and that MR antagonism may represent a novel therapeutic target for this morbid disease.
O Tamimi, A Kouatli, J AlAtta, A Hussain, A Jelly, S Shahrani, A AlKurayf, A Galal
King Saudi Bin Abdul-Aziz University for Health Sciences, Riyadh, Saudi Arabia; King Faisal Specialist Hospital and Research Centre, Jeddah, Saudi Arabia; King Abdulaziz University Hospital, Jeddah, Saudi Arabia; North West Armed Forces Hospital, Tabuk, Saudi Arabia; Khamis Mushait Armed Forces Hospital, Khamis Mushait, Saudi Arabia; Riyadh Military Hospital, Riyadh, Saudi Arabia; King Fahd Armed Forces Hospital, Jeddah, Saudi Arabia
Address correspondence to Maha alDabbagh; e-mail:
Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature that leads to right heart failure and eventually death. Pulmonary hypertension (PH) is a pathophysiological condition defined by an increased mean pulmonary arterial pressure of >25 mm Hg at rest. Pulmonary hypertension can develop in association with or as a consequence of various underlying diseases. According to the Dana Point classification, pulmonary hypertension is categorized into 5 major groups, summarized by the clinical classification of PH. Group 1 comprises pulmonary arterial hypertension (PAH). Groups 2, 3, 4, and 5 categorize PH associated with, respectively, left heart disease, lung diseases and/or hypoxemia, chronic thromboembolic disease, and various conditions with unclear and/or multifactorial mechanisms. The consensus statement of pulmonary vascular disease of the pediatric task force (Panama 2010) has reclassified pediatric patients into 10 major categories, as pediatric PH is multifactorial. In light of this, our aim was to investigate the pattern, outcome, survival, and causes of pulmonary hypertension in children from different referral PH centers in the Kingdom of Saudi Arabia. Our methods included retrospective data from January 2006 till October 2012 for the age group from 3 months to 18 years with referred/diagnosed pulmonary hypertension. Contributors were from seven centers in five different cities distributed over four major districts of the kingdom. The echocardiography parameter tricuspid regurgitation with a Doppler velocity (TRJV) of more than 2.5 m/sec has been used for the screening for pulmonary arterial hypertension (PAH). These are preliminary data that examine the causes, classifications, associated condition(s), functional class, diagnostic criteria, and management and follow-up strategy in pediatric pulmonary hypertension from different centers in Saudi Arabia.
RR Vanderpool, P Yerly, C Dewachter, S Brimioulle, JL Vachiery, R Naeije
Department of Physiology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium; Department of Cardiology, Erasme University Hospital, Free University of Brussels, Brussels, Belgium
Address correspondence to Rebecca Vanderpool; e-mail:
Right ventricular (RV) failure due to increased pulmonary vascular resistance (PVR) is a common complication of a variety of pulmonary and cardiac diseases. Standard right heart catheterization measurements of mean pulmonary vascular pressures and cardiac output (Q) provide only partial and indirect information on RV function. Adequacy of RV function adaptation to afterload, or RV-arterial coupling, is best evaluated using a ventricular pressure-volume relationship and derived determinations of arterial elastance (Ea) as a measure of afterload and maximal elastance (Ees) as a measure of contractility. Adequate Ees/Ea can be obtained with a single-beat method based on instantaneous ventricular pressure and an integration of ejected flow for instantaneous changes in volume. The aim of this study is to investigate the feasibility of measuring RV-arterial coupling using both an invasive method (echo-derived volume and fluid-filled catheter-measured pressures) and a noninvasive method, with both pressure and volume measured with echocardiography. Measurements were made in 13 patients with pulmonary hypertension (PH) or undergoing clinical right heart catheterization for diagnostic purposes. Blood flow velocity through the RVOT was measured with pulsed Doppler. Right ventricle pressure was measured with the tip of the catheter in the right ventricle (catheter-measured) and from the tricuspid regurgitation jet velocities (Doppler-derived). Doppler-derived RV pressure was calculated from the TR-jet velocities with a point-by-application of the simplified Bernoulli equation (P = 4 × v2 + right atrial pressure). A single-beat method was used to calculate Ees, pulmonary artery effective elastance (Ea) from the synchronized RV pressure, and PA blood flow velocities. The patients have varying degrees of PH, with a mean pulmonary artery pressure (mPpa) of 42.5 ± 10.9 mmHg, cardiac output of 4.1 ± 1.1 L/min, and a PVR of 6.4 ± 4.0 mmHg/(L/min). Measured invasively, Ees and Ea were 1.6 ± 0.7 and 1.4 ± 0.7mmHg/mL, respectively, resulting in a coupling ratio (Ees/Ea) of 1.2 ± 0.6. When measured noninvasively, Ees and Ea were 2.0 ± 1.0 and 1.4 ± 0.7 mmHg/mL, respectively, resulting in an Ees/Ea of 1.6 ± 0.6. Investigating the effect of disease severity on RV contractility, afterload, and the coupling, the correlations of Ees, Ea, and Ees/Ea to PVR were found. Ees increased slightly with disease severity (invasive: 0.07 × PVR; noninvasive: 0.17 × PVR). Ea also increased with disease severity (invasive: 0.13 × PVR; noninvasive: 0.12 × PVR). However, the increase in Ea was more than Ees resulting in a negative relationship between Ees/Ea and PVR (invasive: −0.05 × PVR; noninvasive: −0.03 × PVR). In conclusion, it is possible to measure Ees/Ea noninvasively with Doppler echocardiography, but more validation is needed. This method should be validated against coupling ratios derived using high-fidelity catheter-measured pressures and MRI-measured volumes. Additionally, a clinical validation should be conducted to determine if Ees/Ea predicts exercise capacity and survival in patients.
AC Mbakwem, MO Kehinde
Cardiology Unit and Hematology Unit, Department of Medicine, College of Medicine, University of Lagos, Lagos, Nigeria
Address correspondence to Amam Mbakwem; e-mail:
Pulmonary hypertension is a relatively common complication in adult patients with sickle cell disease. Chronic hemolysis and asplenia have been identified as the pathological link between hemolytic anemia and pulmonary hypertension. Some work has been done to evaluate the electrocardiographic pattern of adult patients with sickle cell disease. However, there is little work on the peculiarities, if any, in the sickle cell disease patient who has pulmonary hypertension. We therefore evaluated the electrocardiographic peculiarities of sickle cell disease patients with pulmonary hypertension in our institution. Participants were recruited from the adult sickle cell clinics of the Lagos University Teaching Hospital and were eligible if they were 18 years or older in age, had electrophoresis pattern of hemoglobin SS, and were in steady state. Clinical data of the subjects were obtained, and a 12-lead resting ECG was performed. A transthoracic echo was used for cardiac evaluation, and the peak regurgitant jet velocity was used to estimate the right ventricular pressure gradient, making use of the Bernoulli equation. Pulmonary systolic artery pressure was computed by adding the estimated right atrial pressure. Our results included the data for 79 subjects (25 males and 54 females). Mean age of the subjects was 30.34 ± 10.12 years, and 97.4% had the HBSS genotype. Mean number of pain crises/year was 1.51 ± 0.86, and mean number of blood transfusions/year was 1.47 ± 2.43 L. Mean ejection fraction was 61.03% ± 0.11%, and mean PASP was 17.18 ± 11.58 mmHg. About 27% of the patients had PASP > 25 mmHg, and 14% had PASP > 30 mmHg. PHT, defined as echo PASP ≥ 36 mmHg, was seen in 6 (7.2%) of the subjects (3 males and 3 females). The mean ECG heart rate was 72.25 ± 14.56 bpm, PR interval 0.18 ± 0.03 seconds, and QRS duration 0.07 ± 0.01 seconds. Only one subject had left axis deviation. Left ventricular hypertrophy was present in 36 (45.6%) of the subjects according to Sokolow-Lyon's criteria and in 10 (12.7%) according to Cornell's criteria. Subjects with pulmonary hypertension had significantly higher QT intervals and left ventricular voltage using Cornell's criteria, 0.41 ± 0.33 versus 0.37 ± 0.04 (P = 0.01) and 17.83 ± 3.76 versus 13.13 ± 6.63 (P = 0.03), respectively. A positive correlation was seen between PASP and QT interval. We conclude that echo-estimated pulmonary hypertension in patients with sickle cell disease is associated with longer QT intervals and left ventricular hypertrophy, using the Cornell's criteria.
M Matshela
Inkosi Albert Luthuli Central Hospital, Durban, South Africa
E-mail:
Eighty-six (86) pregnant women (mean age of 27 ± 9 years) with pulmonary hypertension, based on our screening echocardiography, were studied throughout their pregnancy to a maximum of 6 months postdelivery. These patients were identified from the high-risk obstetrics and combined obstetrics-cardiology clinics. The definition of pulmonary hypertension and assessment of severity was based on the AHA/ACC/ESC guidelines. Their clinical profiles and echocardiographic parameters were reviewed and analyzed. Their pregnancy outcomes and their echocardiography and clinical parameters/outcomes were reviewed during their postpartum period (within 6 months postdelivery). Based on our study, the main leading group of pulmonary hypertension was primary pulmonary hypertension, followed by preexisting valvular heart disease, with 46.5% and 32.56%, respectively. HIV-associated pulmonary hypertension (18 patients, 45%) was the leading cause of primary pulmonary hypertension, followed by connective tissue diseases (35%) and idiopathic hypertension (20%). However, in terms of mortality among the primary pulmonary hypertension group, idiopathic pulmonary hypertension (odds ratio: 0.33) had a higher mortality, followed by HIV-associated pulmonary hypertension (odds ratio: 0.2) and connective tissue diseases-associated pulmonary hypertension (odds ratio: 0.167). Among the connective tissue diseases, systemic lupus erythromatosis was the most common (78.6%) in this study. Even though pulmonary hypertension is still considered to be a rare entity in pregnancy, its occurrence is associated with high maternal morbidity and mortality. Primary pulmonary hypertension is a leading cause of morbidity and mortality (odds ratio: 0.212) in our study; however, the other groups of pulmonary hypertension are also associated with an increased risk. The main challenges we were faced with in this study were late diagnosis, admissions, and/or referrals, leading to delayed introduction of appropriate treatment. The factors contributing most to high mortality included late presentation with NYHA class III or IV, moderate to severe pulmonary hypertension, markedly dilated right ventricle with impaired RV function, pregnancy stage (third trimester, during labor, or within 1 month postpartum), use of general anesthesia, and advanced HIV status with a CD4 count of less than 100.
M Vélez-Martínez,1 AR Opotowsky,2 PR Forfia3
1 Department of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA; 2 Department of Cardiology, Children's Hospital, Boston, Massachusetts, USA; 3 Department of Cardiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
Address correspondence to Mariella Vélez-Martínez; e-mail:
Pulmonary hypertension (PH) is overall defined by an elevated mean pulmonary artery pressure. The cause of elevated pulmonary pressures, however, can be due to precapillary—namely, pulmonary arterial—hypertension, or postcapillary PH, secondary to left-sided heart disease, with each requiring distinct diagnostics and management. A practical yet powerful noninvasive method for hemodynamic differentiation of PH is needed. In this study, we sought to determine if right ventricular (RV)-pulmonary artery (PA) modeling using simple 2-D echocardiographic and Doppler method could assist in hemodynamic determination in a diverse PH cohort. Echocardiographic and hemodynamic data were retrospectively collected on 116 patients referred to an outpatient PH tertiary-referral center. We then stratified the patients into 4 different quadrants according to their RV-PA relationship, using tricuspid annular systolic plane excursion (TAPSE; ≥2 cm vs. <2 cm) and RV outflowtract Doppler profile characteristics (+ notch, or accel time100 ms, vs. - notch, or accel time > 100 ms). The mean PA pressure of the entire cohort was 43 ± 11 mmHg, the mean pulmonary vascular resistance (PVR) was 6.4 ± 3.9, and the mean pulmonary capillary wedge pressure (PCWP) was 17 ± 7, reflecting the diverse hemodynamic nature of PH within the cohort. Subjects in groups 3 and 4 had markedly elevated PVR versus subjects in groups 1 and 2, with lesser degrees of left heart congestion. Simple RV-PA modeling can be used to identify more severe, precapillary PH, allowing for more effective diagnosis and triage of PH patients for further invasive testing.
H Wilkens, D Bevec
Internal Medical Department V, Saarland University Medical Center, D-66421 Homburg/Saar, Germany
Address correspondence to Heinrike Wilkens; e-mail:
In 2008, a 33-year-old woman with severe pulmonary arterial hypertension, associated with undifferentiated collagen vascular disease, presented with signs of right ventricular decompensation. Diagnosis of pulmonary arterial hypertension was made in the year 2005, with an initial PVR of 1,413 dyn s cm5. She had been treated with bosentan for 3 months in the year 2005, with a need for discontinuation due to increased liver enzymes. PAH-specific medication was changed to inhaled iloprost and sildenafil since the year 2005; sitaxsentan was added in 2006 and changed to ambrisentan in 2011. In 2007, subcutaneous treprostinil was initiated due to progressive deterioration with an increasing NT pro-BNP of 3512 pg/mL, a decrease of 6-minute walk distance from 380 to 319 m, and severe fatigue. A transient improvement was achieved, with a decrease of pro-BNP to 1,427 pg/mL and a 6-minute walk distance of 380 m; however, treatment was tolerated only for 3 months and was discontinued because of local pain and severe diarrhea. In the year 2008, the patient presented with peripheral edema, right ventricular hypertrophy, an RVSP of 97 mmHG, a TAPSE of 17 mm, pro-BNP of 3,509 pg/mL, and a 6-minute walk distance of 290 m. A repeated prostanoid therapy was refused by the patient. Due to the lack of other treatment options, in November 2008 treatment with inhaled aviptadil was initiated, at a dose of 3 × 200 g via the inhalation device Optineb (NEBU-TEC, Germany). A gradual improvement was achieved, with cardiac recompensation. Six months later, pro-BNP was 1,800 pg/mL and the 6-minute walk distance was 340 m; in November 2009, pro-BNP was 622 pg/mL and the 6-minute walk distance was 410 m. In the year 2012, an ongoing improvement can be noted, with 6-minute walk distances between 430 and 475 m, pro-BNP values of 233–543 pg/mL, and persistent pulmonary hypertension but good right ventricular function (TAPSE: 22 m). As no change in concomitant medication was made, we attribute this improvement of the patient to the effect of inhaled aviptadil. Recent reports about the lack of efficiency of aviptadil might be due to insufficient dosing and will be discussed. Therefore, further studies are necessary to evaluate the potential of this treatment option.
E Tatara, J Ozik, N Collier, M North, J Alexander, RA Edwards, J Mazurek, P Forfia
Decision and Information Sciences, Argonne National Laboratory, Chicago, Illinois, USA;
Pfizer, New York, New York, USA; School of Pharmacy, Department of Health Sciences, Northeastern University, Boston, Massachusetts, USA; Penn Heart and Vascular Center, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
Address correspondence to Joe Alexander; e-mail:
Much remains unknown about how dynamic properties of vessels across multiple spatial scales contribute to increased vascular impedance and RV afterload. Some investigators have developed computational models of pulmonary vascular impedance to analyze changes in pulmonary hemodynamics in response to disease; however, these models are generally either lumped-parameter representations that do not explicitly incorporate physiologically meaningful parameters or discrete pulmonary vascular networks focused on mean pressure-flow relationships rather than on dynamic, frequency-dependent characteristics such as impedance. We have developed a computational model of the pulmonary vascular bed to explore how simulated disease conditions affect pulmonary arterial input impedance through vessel obliteration and/or vessel stiffness. The explicitly modeled network components include the pulmonary arteries and arterioles that allows for spatial variation in topology and vessel properties such as vessel wall elasticity, which are neglected in lumped-parameter models. Numerical synthesis of the vascular network involved the construction of a three-dimensional vascular tree for hemodynamic modeling. The network creation parameters included the vessel in-plane rotation angle (i.e., the branch angle), the out-of-plane rotation angle, the ratio of parent- to daughter-branch lengths, the ratio of parent- to daughter-branch diameters, the parent-to-daughter branching ratio, and the number of generations in the network. At each generation, bifurcating or trifurcating daughter branches were created from parent branches, such that each daughter branched from the parent according to the in-plane rotation angle and each daughter was rotated around the parent branch according to the out-of-plane rotation angle. Resistance and impedance for each vessel within the synthetic vascular network were calculated as follows. First, the pulmonary arterial network was constructed and stored as a collection of vessel segment objects, resulting in a network of 15 discrete generations (16,000 vessels) and 11 aggregated generations, for a total of approximately 67 million simulated vessels. Next, for each vessel segment we calculated the segment resistance and impedance. Physical properties, including plasma density and viscosity, hematocrit, and vessel wall elasticity, were also calculated for each of the vessels in the generated vascular tree. Network resistance and impedance were calculated by aggregating vessel segments. To test the performance of the synthetic network, we examined echocardiographic and hemodynamic data from a cohort of patients seen by the PH service at the Hospital of the University of Pennsylvania who underwent clinically indicated RHC and a transthoracic echocardiogram and who had interpretable right ventricular outflow tract pulsed-wave Doppler flow velocity envelopes (FVERVOT) performed within 4 months of the RHC. The cohort included patients with differing degrees of systolic deceleration, or “notching,” of FVERVOT tracings, as well as controls with no systolic notching. For several patients with clear Doppler evidence of mid-systolic notching, we digitized FVE contours and combined them with PAP waveforms from the same patients to calculate estimates of their respective pulmonary arterial impedances. We then demonstrated our ability to tune parameters in a branched synthetic network to recapitulate those impedances measured for individual patients. In conclusion, our preliminary results suggest that changes in the impedance magnitude and phase over a specific range of frequencies in a discrete branched synthetic vascular network can give rise to the type of systolic decelerations (notchings) observed in some patients with significant pulmonary hypertension. Ongoing work will make use of larger patient data sets to explore what vascular properties within the synthetic network likely account in these patients for a variety of clinically observed notching patterns.
X Cheng
Pulmonary Vascular Disease Center, Fuwai Cardiovascular Hospital, Beijing, China; and National Cardiovascular Center, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
This article briefly summarizes the history and current state of pulmonary vascular disease and research in China. In Chinese traditional medicine, the terms “pulmonary vascular disease” (PVD) and “pulmonary hypertension” do not exist. Instead, they were usually referred to as “syndrome of breathlessness, chest discomfort, or syncope.” In 1952, the first right heart catheterization in China was performed by Professor Huang. Since then, cardiopulmonary hemodynamics studies have been widely carried out clinically. Cardiovascular angiography was introduced in 1958. The first monograph, Pulmonary Vascular Diseases (in Chinese), was published in 1993. The first book, Right Ventricular Disease—Base and Clinic (in Chinese), was published in 2008. Typical Case Reports of PVD, including about 50 kinds of PVD, will be published in 2013. In Pulmonary Vascular Diseases, PVD is defined as “the disorders in local or whole pulmonary circulation due to abnormal pulmonary structure and/or function.” A modified classification of PVD was proposed in 1991 based on 241 cases of various PVDs in Fuwai Cardiovascular Hospital. The classification was divided into large- and small-vessel diseases. The former covered arteries and veins and congenital and acquired diseases. The category of small-vessel lesions was similar to vascular pathologic types proposed by Wagenvoord. A novel concept of the right ventricular system was proposed in 2010. Since the 1980s, studies on pulmonary hypertension have been included in national key projects. Studies on pulmonary thromboembolism were added since the 1990s, and studies on right heart disease since 2011. The first center for PVD was established in China in 1972 (the former Division of Pulmonary Heart Disease), and to date five pulmonary vascular centers have been established. Clinically, the majority of PVDs encountered have been various types of pulmonary hypertension, pulmonary thromboembolism, pulmonary vasculitis, pulmonary artery tumors, pulmonary vessel abnormality, and various primary or secondary right heart disorders. There have been three stages in the research on pulmonary hypertension. (1) The phase of clinical hemodynamic application for congenital heart disease, rheumatic heart disease, etc. (1952–1985). (2) The phase of acute vasodilator testing and calcium channel blocker therapy prior to pulmonary artery hypertension (PAH) target treatment (1986–2005): (a) Studies on rest and exercise hemodynamics and drug screening in patients with chronic obstructive pulmonary disease (COPD) and cor pulmonale. (b) Studies on hemodynamics in PAH associated with systemic lupus erythematosus, which found that 11% of patients presented with pulmonary arterial hypertension (9 out of 84). (c) Studies comparing hemodynamics with pathologic changes in cases of congenital heart disease associated with PAH, which found 59 operable pulmonary vascular lesions grade I-II/IV; of these, 14 cases had bidirectional shunt with cyanosis. (d) Studies on hemodynamics and acute vasodilator test in obliterative pulmonary hypertension (primary pulmonary hypertension [PPH] and chronic thromboembolic pulmonary hypertension [CTEPH]) in 1980s. A total 115 cases of obliterative pulmonary hypertension were enrolled in the study (in a single center), including 46 patients with CTEPH and 69 patients with PPH. Hemodynamics and acute vasodilator testing were performed: (i) inhalation of pure oxygen in 50 cases; (ii) Nifedepine 20 mg sublingually in 21 cases; (iii) ligustrajine (an extract from a Chinese medicine herb), 80 mg intravenously in 18 cases. e. The natural course in 175 patients with obliterative pulmonary hypertension was surveyed from 1974 to 1995. 130 cases were followed up (74.2%), for a mean of 5.86 ± 4.63 years (0.5–21). The total mortality of the patients (53 cases of PPH, 70 cases of CTEPH, and the other 7 cases) was 55.4%, of which 53.0% were in PPH and 38.0% in CTEPH (P < 0.05). Survival after 2, 3, 5, and 10 years in PPH and CTEPH was 71.8%, 67.2%, 41.0%, and 21.7% and 95.8%, 91.6%, 71.3%, and 46.2%, respectively. (3) The phase of PAH target treatment (2005–present). The primary studies on PAH completed and currently being carried out include the following. a. Studies on drug therapy for PAH patients (idiopathic and hereditary PAH, PAH associated with congenital heart disease, and PAH associated with connective tissue diseases, etc.), have been completed for sildenafil, vardenafil/iloprost (inhaled), bosentan, and atorvastatin, among others. b. A national registry of PAH is being implemented. c. A survival comparison of patients with PAH between two periods in China—72 cases in 1999–2004, for which the survival rates at 1, 2, 3, and 5 years were 68.0%, 56.9%, 38.9%, and 20.8%, respectively, versus 276 cases in 2007–2009, for which the 1- and 3-year survival rates were 92.1% and 75.1%, respectively—which indicated that PAH patient survival after target treatment has improved markedly. d. Studies on pathogenesis of PAH have included (i) genomic research of hereditary and sporadic PAH, which found that MUC6 and two G protein coupled receptor family genes (GPCR2R3, GPCR9G10) related significantly to PAH; studies on the cGMP signal pathway and the role of micRNA in PAH, among others, were investigated; (ii) observation of molecular genetics and clinical features in Chinese idiopathic and heritable PAH patients; (iii) a study showing that bone morphogenetic protein receptor-II mutation Arg491 Trp caused malignant phenotype of familial pulmonary hypertension. e. In China, studies on plateau genome have been performed, including genomic studies on hypoxia tolerance in plateau native population adaptation and evolution, and tolerance and acclimatization to hypoxia for people arriving quickly in Tibet. The results showed that some hypoxia tolerance candidate genes, especially hypoxia-induced factor 2α, EGLN 1(hypoxia-induced factor prolyl hydroxylase), and a few hemoglobin genes, displayed higher PBS values. There was more significant difference on PBS between Tibetan and Han people. The findings indicated that these genes underwent a burden of greater selection. The research also revealed that climbers showed higher methylated levels on CpG islands when they arrived in plateau (1 month later) from plain. However, there were no significant changes in extron, intro, and UTR, which indicated that hypoxia could impact the methylated level and gene expression by the regulation of methylation. Regarding research on pulmonary thromboembolism, in the past pulmonary thromboembolism was recognized as a rare disease in China. But over time, it has become as common a disease as in Western countries. For example, Wang and colleagues described that within their collaborative group of pulmonary thromboembolism, the prevalence of disease increased from 221 cases to 3,185 cases (14.4 times) during a 10-year period due to promotion of diagnostic awareness and technology. During the same time period, the mortality from pulmonary thromboembolism was dramatically reduced, from 24% to 8.7%. The thromboendarterectomy of the first patient with CTEPH was performed in 1994, and a monograph, Pulmonary Embolism and Pulmonary Thromboendarterectomy (in English) was published in 2011. A national prevention and management network system for pulmonary thromboembolism is being constructed. The investigation of some patients with pulmonary thromboembolism showed that fibrinogen Thr312Ala mutation resulted in a decreased transformation from plasma fibrin to fibrinolysin. The results also showed that fibrinolysin Ala601Thr could lead to decreased activity of fibrinolysin, which might contribute to thrombosis in patients with venous thromboembolism. Some F5 genetic variants were also found to be significantly associated with pulmonary thromboembolism. To summarize, research on PVDs, especially various pulmonary hypertensions, has been conducted in China. Since 2005, studies on pulmonary hypertension have been extensively carried out, including genomics, diagnosis, treatment, a national registry for PAH, etc. At the same time, studies of right ventricular function and right heart failure have also begun to attract more attention. The prevalence of congenital heart disease–associated PAH, in particular Eisenmenger syndrome and hypoxic hypertension and especially plateau hypoxia-induced pulmonary hypertension, is higher in China, so we must be concerned about these issues. PVD is a common multidisciplinary disease, which needs a cooperative research of diverse disciplines, including clinical medicine and basic medicine to resolve this difficult field.
G Maarman, L Blauwet, K Sliwa, S Lecour
Hatter Institute for Cardiovascular Research in Africa (HICRA), Observatory, South Africa; Department of Medicine, Faculty of Health
Sciences, University of Cape Town, Rondebosch, South Africa; Mayo Clinic, Rochester, Minnesota, USA
Address correspondence to G. Maarman; e-mail:
Pulmonary arterial hypertension (PAH) is a disorder characterized by elevated pulmonary arterial pressure that leads to cardiac hypertrophy and ventricular dysfunction. Current treatments are only marginally effective, and additional therapies are required. Melatonin is a natural product that has been shown to be cardioprotective against hypertension and myocardial infarction. We therefore propose that a chronic melatonin treatment may be cardioprotective in a rat model of monocrotaline (MCT)-induced PAH. Male Long Evans rats (150–175 g) received a single subcutaneous injection of MCT (80 mg/kg), which induced PAH after 28 days. Melatonin was given in the drinking water (4 mg/kg/day) for the 28-day period. Cardiac hypertrophy was confirmed with the ratio of the right ventricle weight over heart weight (RVW/HW). Cardiac functional parameters were assessed at 0 and 28 days using isolated heart perfusion and/or echocardiography. These parameters included right ventricular systolic (SP) and diastolic pressure (DP), ejection fraction (EF), and fractional shortening (FS). MCT increased RVW/HW, reduced EF (92.84% ± 1.33% vs. 60.53% ± 4.23%, P < 0.0003) and FS (28.23% ± 2.68% vs. 61.03% ± 2.89%, P < 0.0002), and increased SP and DP. Chronic administration of melatonin in MCT-treated rats improved EF (60.5% ± 4.2% vs. 84.1% ± 1.7%, P < 0.0008), FS (28.2% ± 2.7% vs. 48.7% ± 2.1%, P < 0.0005), SP, and DP. In conclusion, our data demonstrate that chronic melatonin improves cardiac function in MCT-induced PAH and suggests a cardioprotective role of melatonin in PAH.
G Chen, JG He, ZH Liu, Q Gu, XH Ni, CM Xiong
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Beijing, People's Republic of China; National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
Address correspondence to Xiong Changming; e-mail:
The purpose of the Chinese study was to compare the demography, hemodynamics, and clinical features of patients with different classifications of pulmonary hypertension (PH) and to improve diagnosis and treatment. Thirty-one clinical centers in China enrolled patients with pulmonary hypertension diagnosed by ultrasound cardiogram and right heart catheterization during the period from May 2007 to October 2010. The inclusion criteria were as follows: (1) age ranging from 18 to 75; (2) 6-minute walk distance ranging from 100 to 500 m; (3) mean pulmonary arterial pressure (PAP) ≥25 mmHg (30 mmHg with exercise), pulmonary capillary wedge pressure (PCWP) ≤15 mmHg, and pulmonary vascular resistance ≥240 dyn s cm−5. Age, gender, sex, BMI (body mass index), symptoms and signs, WHO classification, six-minute walk distance (6MWD), and hemodynamics were recorded. A total of 551 patients with four classifications of pulmonary hypertension were enrolled, including idiopathic pulmonary arterial hypertension (IPAH, n = 150), pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH, n = 273), pulmonary arterial hypertension associated with connective tissue disease (CTD-PAH, n = 164), and chronic thromboembolic pulmonary hypertension (CTEPH, n = 64). Patients with CHD-PAH were the youngest and had the highest number and lowest BMI among all the groups, while the patients with CTEPH showed the opposite results.
Patients with CTEPH had the highest frequencies of syncope (P < 0.0001), and patients with CTD-PAH and CHD-PAH had the shortest and longest 6MWDs, respectively (P < 0.0001). ECG of the majority of patients showed hypertrophic right ventricle. Almost half of the patients with IPAH, CTD-PAH, or CTEPH were in WHO pulmonary function classifications II and III, and 69.9% of the patients with CHD-PAH were in WHO pulmonary function classification II. Mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) of patients with CHD-PAH were the highest among all the groups (P < 0.001). In conclusion, the patients enrolled in this study consisted mainly of young females. Most of the patients with IPAH were at a severe stage when diagnosed, and pulmonary arterial hypertension associated with congenital heart disease was the most common classification of pulmonary hypertension in this study. Patients with CHD-PAH had a reserved WHO pulmonary function classification and exercise tolerance even with the highest mPAP and PVR among all the patients, indicating that the heart function of patients with CHD-PAH was not parallel to their mean pulmonary arterial pressure and pulmonary vascular resistance.
CN Chen, N Hajji, MR Wilkins, L Zhao
Centre for Pharmacology and Therapeutics, Division of Experimental Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom
Address correspondence to Lan Zhao; e-mail:
Epigenetic programming, dynamically regulated by histone acetylation, has been implicated in vascular remodeling and may contribute to the pathogenesis of pulmonary arterial hypertension (PAH). Aberrant histone deacetylase (HDAC) activity has been shown in the lungs of PAH patients, and pharmacological intervention with HDAC inhibitors can be beneficial in a chronic hypoxic rat model through mechanisms such as antiproliferation and immune modulation. Herein we explored the pharmacologic effects of HDAC inhibitors in a more severe and irreversible experimental PH model, induced by monocrotaline (MCT), and aimed to define the underlying molecular mechanisms. Two weeks after the MCT (60 mg/kg) injection, rats were treated with HDAC inhibitors: valproic acid (VPA), a class I HDAC inhibitor, or vorinostat, a broad-spectrum inhibitor of class I, II, and IV HDACs, for 2 weeks. HDAC activity was examined by measuring levels of acetylated histones H3 and H4 and protein expression (P21, Bcl-2, survivin, and TIMP-1) by Western blotting. In this study, treatment with VPA (300 mg/kg/day) or SAHA (50 mg/kg/day) significantly reduced MCT-induced pulmonary arterial pressure elevation (PAP; M4W: 40.4 ± 3.4 mmHg; VPA: 27.6 ± 2.4 mmHg; SAHA: 21.7 ± 1.4 mmHg; P < 0.001), right ventricular hypertrophy (RVH; M4W: 0.57 ± 0.05; VPA: 0.41 ± 0.03; SAHA: 0.32 ± 0.00; P < 0.01), and peripheral pulmonary vessel muscularization (M4W: 79.8% ± 1.0%; VPA: 72.0% ± 1.1%; SAHA: 69.2% ± 2.1%; P < 0.01). No significant changes in heart rate or systemic SBP were observed in treated groups. Treatment with VPA and SAHA led to increased P21 expression and reduced Bcl-2 and survivin expression (P < 0.05) in lung homogenates and also elevated acetylation of histones H3 and H4, reflecting decreased activities of HDAC. Furthermore, these two inhibitors effectively reduced the abnormal overexpression of tissue inhibitor metalloproteinase-1 (TIMP-1; P < 0.001), which has been implicated in excess extracellular matrix deposition and vascular remodeling in PAH. In conclusion, HDAC inhibitors VPA and SAHA achieved antiremodeling effects, leading to partial reversal of MCT-induced PH. The data add to the body of evidence suggesting that HDACs are a promising therapeutic option for PAH.
A Ashek, O Dubois, H Jones, W Gsell, M Wilkins, L Zhao
Division of Experimental Medicine, Imperial College London, London, United Kingdom
Address correspondence to Lan Zhao; e-mail:
Pulmonary arterial hypertension (PAH) is a lethal disease of progressive vascular remodeling. The molecular imaging positron emission tomography (PET) offers enormous potential for monitoring cellular and biochemical events in inaccessible tissue and assessing antiproliferative therapeutic agents. We explored 18F-fluorodeoxyglucose (18F-FDG) PET for the assessment of pulmonary arterial hypertension (PAH) pathology in the monocrotaline (MCT) rat model and the effect of antiproliferative therapies (dichloroacetate [DCA] 70 mg/kg, imatinib 100 mg/kg, and sunitinib 10 mg/kg/day). Using a Siemens Inveon small-animal multi-modality PET/CT system, dynamic emission scans were acquired for 60 minutes in list-mode after 18F-FDG injection (37 MBq). The whole-lung tissue time-activity curve (TAC) was calculated from lung PET images coregistered with the region of interest (ROI) on CT lung images where lung boundaries were clearly visible. Cumulative images over 0–60 minutes were used for kinetic analysis of tracer uptake. Serial blood samples were taken through a femoral arterial line during PET scanning for plasma activity input function. Kinetic influx rate constants (Ki) were estimated as the slope of the linear regression from the Patlak plot–FDG uptake. Kinetic analysis of FDG-PET scans indicated a progressive increase of FDG uptake in MCT rat lung (1, 2, and 4 weeks after injection) as the disease progressed. Significant reduction in lung FDG influx Ki was observed after 2 weeks of DCA, imatinib, or sunitinib treatment (4 weeks MCT end point), in line with changes in the histology, for example, the proliferation index Ki67 score. Calculated FDG uptake was confirmed by direct measurement of tissue 18F-FDG in γ-counter. Furthermore, consecutive FDG-PET scans were performed to follow the pulmonary response to DCA and imatinib in MCT rats longitudinally. Interestingly, a significant drop in FDG uptake was observed as early as 2 days after imatinib treatment. This in vivo study established a clinically applicable dynamic FDG-PET protocol with kinetic analysis. Our data provide evidence that FDG-PET is useful in reporting the pulmonary pathology in response to targeted treatments in PAH.
E Kolosionek, J King, D Rollinson, RT Schermuly, F Grimminger, G Butrous
Division of Cardiopulmonary Sciences, University of Kent, Canterbury, United Kingdom; Zoology Department, Natural History Museum, London, United Kingdom; Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
Address correspondence to Ewa Kolosionek; e-mail:
Schistosomiasis is a global parasitic disease and ranks second to malaria in terms of socioeconomic and public health importance in tropical and subtropical areas. Schistosomiasis has been included among the group of associated pulmonary arterial hypertension (PAH). It can induce pulmonary vascular remodeling and involves numerous molecular signaling cascades governing VSMC migration, differentiation, and proliferation. But the exact pathogenesis is still unclear. The hypothesis for this study was as follows: vascular changes in the lung are due to the patchy nature and unequal distribution of granulomas and inflammation caused by Schistosoma eggs in the lung. Our methods and results included the following data: changes 12 weeks posttransfection demonstrate hepatomegaly in all infected mice (hepatic weight changes from 1;437 ± 532 mg in control mice to 4;606 ± 566 mg in infected ones [P < 0.0001]). There was no change in heart weight ratio (RV/(LV + S)): 0.276 ± 0.032 in control mice versus 0.297 ± 0.017 in infected ones (NS). In the lungs of infected animals, eggs were detected in 24 of 43 lobes (56%), and worms were seen in 8 of 43 lobes (18%). Granulomas were present in 31 of 43 lobes (72%) and were centered around eggs but not in proximity to the adult worms. No remodeling was observed in the small vessels (0–70 μm). In the medium vessels (70–150 μm), 42% were partially muscularized and 42% were fully muscularized. In the group of large vessels (>150 μm), 40% were partially muscularized and 60% were fully muscularized. It was observed that all muscularized vessels were inside or in close proximity to granulomas. No remodeled vessels were seen distant to granulomas. There was a trend observed that remodeled vessels were present mostly (60% of all remodeled vessels observed) near granulomas of 200–400-μm diameter, whereas only 34% could be found near small granulomas (0–200-μm diameter) and 6% were seen near large granulomas (>400-μm diameter). This study supports the major role of inflammation in vessel remodeling. First, cercariae infection and resulting inflammation cause remodeling of the vessels, and this remodeling always occurs in close proximity to granulomas. Second, there was a trend in the size of granuloma and vessel changes, where remodeled vessels were most often observed to be located near medium-sized granulomas. Third, adult worms can be present in the lungs of infected animals but are not associated with granuloma formation or vessel changes.
S Gairhe, IF McMurtry
Departments of Pharmacology and Medicine and Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
Address correspondence to Salina Gairhe; e-mail:
Occlusive arteriopathy in pulmonary arterial hypertension (PAH) has been associated with hyperproliferation of pulmonary arterial endothelial and smooth muscle cells (PAECs and PASMCs, respectively). We have observed increased expression of the sphingosine 1-phosphate synthetic enzymes sphingosine kinase 1 and 2 in the occlusive lesions of both rat and human PAH lungs. Since sphingosine 1-phosphate has pro-proliferative effects on numerous other cell types, we investigated whether the phospholipid also induces proliferation of cultured rat PAECs and PASMCs. Rat PAECs and PASMCs were cultured on 6 well plates. After 24 hours of serum starvation, the cells were treated with 5 μM sphingosine 1-phosphate or vehicle (0.1% MeOH) at 24, 48, and 72 hours. Media with 10% serum were used as a positive control. Cell numbers were determined using a Countess Automated Cell Counter. Sphingosine 1-phosphate increased the number of PAECs and PASMCs over time, and this effect was more pronounced in PAECs than in PASMCs. The sphingosine 1-phosphate-induced increase in cell number could be attributed to an increase in cell proliferation. In conclusion, the pro-proliferative effects of sphingosine1-phosphate on cultured rat PAECs and PASMCs support the possibility that the phospholipid plays an important role in occlusive lesion formation in PAH.
OA Minai, Q Nguyen, S Mummadi, R Gudavalli, RA Dweik, K McCarthy
Department of Internal Medicine, Medicine Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA; Department of Pulmonary, Allergy, and Critical Care Medicine, Respiratory Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA; Tuality Pulmonary and Sleep Medicine, Hillsboro, Oregon, USA; Department of Pulmonary Medicine and Critical Care, Iowa Clinic, West Des Moines, Iowa, USA
Address correspondence to Omar A. Minai; e-mail:
We aimed to determine whether abnormal heart rate recovery at one minute of rest (HRR1) after the 6-minute walk (6MW) test (HRR1 < 16 beats per minute) predicts survival and hospitalization in patients with pulmonary hypertension associated with connective tissue diseases (CTD-PAH). Patients with pulmonary hypertension and a diagnosis of systemic sclerosis (SSc), systemic lupus erythematosus (SLE), or mixed connective tissue disease (MCTD) who underwent the 6MW test between August 1, 2009, and October 30, 2011, were included in the analysis. Patients on beta-blocker therapy at the time of the 6MW test were excluded. 66 patients with CTD-PAH completed the 6MW test. Compared to patients with HRR1 > 16, patients with HRR116 were older (58 ± 15 years vs. 52 ± 16 years; P = 0.001), were less likely to be female (75% vs. 97%; P = 0.017), and had worse WHO FC (P = 0.003). Patients with HRR1 < 16 and HRR1 > 16 did not differ significantly in baseline pulmonary function test variables (% predicted FVC, FEV1, and DLCO). Patients with abnormal HRR1 had lower 6MW distance (272.3 ± 94.0 meters vs. 367.7 ± 103.7 m; P < 0.001). Patients with abnormal HRR1 had higher incidence of mortality (44% vs. 13%; P = 0.006) and PH-related hospitalizations (49% vs. 13%; P = 0.002). Compared to 6MW distance, HRR1 was a better predictor of PH-related hospitalizations (C statistic for HRR1 = 0.735 vs. C statistic for 6MW distance = 0.607). In patients with PH, abnormal HRR1 (defined as HRR1 < 16) after the 6MW test is a strong predictor of survival and hospitalization. This may have clinical implications, since HRR1 after the 6MW test is a noninvasive, low-cost, and easily obtained measurement that can aid in predicting clinical outcome in patients with PH associated with CTD.
OA Minai, S Mummadi, R Gudavalli, M Xu, K McCarthy, RA Dweik
Department of Pulmonary, Allergy, and Critical Care Medicine, Respiratory Institute, Cleveland Clinic, Cleveland, Ohio, USA; Department of Pulmonary Medicine and Critical Care, Iowa Clinic, West Des Moines, Iowa, USA; Department of Qualitative Health Sciences, Cleveland Clinic, Cleveland, Ohio, USA
Address correspondence to Omar A. Minai; e-mail:
Reduced heart rate recovery (HRR) after 6-minute walk testing (6MWT) has been shown to be a predictor of clinical worsening. We sought to evaluate whether HRR after 6MWT could predict survival and hospitalization in patients with pulmonary arterial hypertension (PAH). Data were obtained by review of the medical records. Heart rate recovery was defined as the difference in the heart rate at the end of 6MWT and at one minute (HRR1), 2 minutes (HRR2), and 3 minutes (HRR3) of rest. Between August 1, 2009, and March 30, 2010, 90 consecutive patients with PAH (IPAH [N = 62] and scleroderma-associated PAH [N = 28]) underwent 6MWT and were included in the analysis. HRR1 was a better predictor of survival and hospitalization than HRR2 or HRR3. There were 14 deaths over the follow-up period of 14 months. By multivariable analysis, the best predictors of increased mortality were HRR1 < 13 (HR [CI], 9 [1.92, 50], P = 0.006), mRAP (HR [CI], 1.16 [1.06, 1.27], P = 0.002), and presence of pericardial effusion (HR [CI], 4.37 [1.17, 16.37], P = 0.02). Fifteen patients were hospitalized for worsening PH. HRR1 < 16 was a strong predictor of survival (HR [CI], 9 [2, 50], P = 0.004); however, the best predictors by multivariable analysis were elevated B-type natriuretic peptide (HR [CI], 1.002 [1.0, 1,003], P = 0.036) and WHO FC 3 or 4 (HR [CI], 8.3 [1.67, 38.5], P < 0.001). Patients with HRR1 > 24 had a very low rate of hospitalization or mortality. Our conclusions follow that HRR1 after 6MWT is a strong predictor of survival and hospitalization in patients with PAH.
The soluble guanylate cylase stimulator riociguat prevents tobacco smoke–induced pulmonary hypertension and emphysema
A Pichl, N Parajuli, M Seimetz, JP Stasch, R Frey, RT Schermuly, W Seeger, F Grimminger, HA Ghofrani, N Weissmann
Universities of Giessen and Marburg Lung Center (UGMLC), Excellence Cluster Cardio-Pulmonary System (ECCPS); Department of Internal Medicine, Medical Clinic II/V, Giessen, Germany; Bayer HealthCare, Wuppertal, Germany
Address correspondence to Norbert Weissmann; e-mail:
Approximately 30%–70% of patients with chronic obstructive pulmonary disease (COPD) also suffer from pulmonary hypertension (PH). Previously, we showed that the soluble guanylate cyclase (sGC) stimulator riociguat completely inhibited emphysema development in tobacco smoke–exposed mice. Against this background, we here ask if PH induced by tobacco smoke in mice can also be prevented by riociguat. C57BL6/J mice were exposed to cigarette smoke for 6 hours/day, 5 days/week, for 6 months (particulate matter 140 mg/m3). In parallel with smoke exposure, mice were treated with either 3 mg/kg or 10 mg/kg riociguat once daily by gavage. Smoke-exposed placebo-treated and non–smoke exposed mice served as controls. Vascular morphometry (degree of muscularization) and right ventricular systolic pressure (RVSP), as well as changes in right ventricular heart weight, were determined after 6 months. Smoke exposure led to PH (RVSP increased from 22.8 ± 0.3 to 28.6 ± 0.5 mmHg; n = 8 each) and right ventricular hypertrophy as well as a shift from nonmuscularized to partially or even fully muscularized vessels. Treatment with either 3 mg/kg or 10 mg/kg riociguat completely prevented the development of PH as well as right ventricular hypertrophy and the structural vascular alterations induced by tobacco smoke exposure. In conclusion, PH, right ventricular hypertrophy, and vascular remodeling, as well as lung emphysema, induced by chronic tobacco smoke exposure of mice can be prevented by riociguat.
P Bobhate, D Cave, R Haugen, J Rutledge, JY Coe, I Adatia
Paediatric Pulmonary Hypertension Clinic, Division of Paediatric Cardiology, Departments of Paediatrics and Anesthesia, Stollery Children's Hospital, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
Address correspondence to Ian Adatia; e-mail:
Children with pulmonary hypertensive vascular disease (PHVD) require cardiac catheterization for diagnosis and therapeutic decision making. Death or need for resuscitation has been reported to occur in 5%-6% of cases. Our objective was to define the risks of cardiac catheterization in children with PHVD at our institution. To this end, we reviewed retrospectively the records of all children with PHVD undergoing cardiac catheterization over a 3-year period, from January 2009 to October 2012. We reviewed all adverse events occurring within 48 hours of cardiac catheterization. All children were evaluated and discussed precardiac catheterization by both a PHVD and a pediatric anesthesia specialist. A protocol was established with the following key components. All children undergoing follow-up cardiac catheterization received their PHVD medications according to the usual home schedule: all children received a dose of sildenafil, 1 mg/kg, by nasogastric tube before the end of the case and 20 minutes before tracheal extubation. Anesthesia was provided following a standard regime using remifentanil, ketamine, rocuronum, and local anesthesia at the vascular access site. A small number of cases exhibited variation from this standard based on individual patient considerations. Anesthetic management included rapid-sequence tracheal intubation with a cuffed endotracheal tube and mechanical ventilation in 51/52 patients. End-tidal carbon dioxide (ETCO2) was continuously monitored to maintain it at 35–45 mm Hg. Oxygen consumption was measured by either mass spectroscopy or the breath-by-breath method. Our results were as follows. 52 patients (32 males), with a median age of 4 years (range: 3 months–17 years) and a median weight of 13.9 kg (range: 3.3–77 kg), underwent 69 cardiac catheterization procedures. In 54 cases (79%), children underwent acute pulmonary reactivity testing. Diagnostic groups included isolated pulmonary arterial hypertension (IPAH; 28%), PHVD associated with unrepaired congenital heart disease and systemic to pulmonary shunts (27%), PHVD associated with repaired congenital heart disease (25%), PHVD due to left heart disease (6%), and PHVD due to bronchopulmonary dysplasia (13%). The mean pulmonary artery pressure was 43 ± 18 mmHg; mean pulmonary vascular resistance indexed was 9.6 ± 6 Woods units/m2, with an Rp/Rs ratio of 0.65 ± 0.3. The most common adverse event was transient loss of distal leg pulse in 3 patients (4.3% of procedures and 5.7% of patients). Serious adverse events occurred in 2 patients, both with IPAH and suprasystemic PA pressures. Hypotension during the cardiac catheterization, treated with fluid and short-term inotrope administration, occurred in one patient, related to balloon rupture of the flow-directed catheter in the left PA. One patient required initiation of mechanical extracorporeal life support (ECLS) 36 hours after the procedure for refractory progressive right heart failure and later underwent successful lung transplantation. There were no deaths. In conclusion, in our experience of 69 cardiac catheterizations in children with PHVD, serious adverse events during the cardiac catheterization occurred in 1/69 (1.5%) and within 48 hours in 1/69 (1.5%). There was one adverse event directly related to the cardiac catheterization and one adverse event that occurred 36 hours after cardiac catheterization due to progression of right heart failure. Patients with IPAH and suprasystemic PA pressures are most at risk for adverse events, and the availability of ECLS for late deterioration of patients in right heart failure is prudent. Close collaboration with pediatric anesthesia, a standardized approach, and the use of sildenafil before the end of the cardiac catheterization may have contributed to the decreased frequency of adverse events.
SR Joshi, J McLendon, M Matar, JG Fewell, M Oka, IF McMurtry, WT Gerthoffer
Departments of Biochemistry and Molecular Biology and Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA; EGEN, Huntsville, Alabama, USA; Departments of Pharmacology and Internal Medicine and Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
Address correspondence to Sachindra Joshi; e-mail:
Severity of pulmonary arterial hypertension (PAH) is associated with progressive vascular remodeling leading to narrowing of pulmonary arteries and formation of occlusive neointimal and plexiform lesions. In patients with severe PAH, the increased pulmonary arterial resistance and pressure ultimately lead to right heart failure and premature death. Inhibition of microRNA (miR)-145, a small, noncoding RNA that regulates smooth muscle cell phenotype, has been shown to prevent the progression of PAH in an experimental model of nonocclusive PAH. Therefore, we hypothesize that inhibiting miR-145 will also reverse the vascular remodeling in an experimental model of occlusive PAH. Adult male Sprague-Dawley rats were injected with subcutaneous vascular endothelial growth factor receptor blocker Sugen-5416, exposed to hypoxia (10% O2) for 3 weeks, and then returned to normoxia (21% O2) for an additional 10 weeks. The SU/Hx/Nx rats were either treated with anti-miR-145 at 8, 10, and 12 weeks or left untreated. At 13 weeks, rats were anesthetized and sacrificed to harvest the lungs. Lungs were inflated through the trachea with 0.5% (w/v) low-melting agarose in 10% neutral buffered formalin (NBF) and immersed in 10% NBF for at least 48 hours. Lung sections were then cut at ~5 mm thickness and paraffin embedded, and 5-μm slices of lung were prepared and stained to visualize tissue structure (hematoxylin and eosin stain, Verhoeff-van Gieson stain for elastin). Treatment with anti-miR-145 showed a distinct reversal of vascular remodeling that includes decreases in medial hypertrophy, occlusive lesions, and, to some extent, plexiform lesions. In conclusion, it appears that miR-145, known to be a master regulator of smooth muscle cell phenotype, plays a significant role in regulating pulmonary vascular remodeling in PAH and that targeting miR-145 signaling by an anti-miR may be a promising new approach to treat severe occlusive PAH.
AM Thomaz, L Zorzanelli, VD Aiello, NY Maeda, RPS Soares, FRBG Galas, LJ Kajita, JL Piccioni, MB Jatene, M Rabinovitch, AA Lopes
Heart Institute, University of São Paulo School of Medicine, Pró-Sangue Foundation, São Paulo, Brazil; and Pulmonary Vascular Research Institute
Address correspondence to Antonio A. Lopes; e-mail:
Pulmonary arterial hypertension (PAH) is a complicating factor in the management of congenital heart disease (CHD) with intracardiac or extracardiac communications. In children with moderate to severe PAH, the risk of serious complications following the surgical repair of shunts (including right cardiac failure and death) is 15%–20% or even higher, and the risk of late, postoperative residual PAH is ~25%. We therefore planned to conduct a study aimed at reducing the risk of severe immediate postoperative complications and the risk of residual PAH at 6 months following surgery to less than 10% in children with moderate PAH (primary objective). The study is also aimed at promoting a statistically significant reduction in pulmonary artery pressure and pulmonary vascular resistance at 6 months after surgery, compared with baseline in children with moderate or severe PAH (secondary objective). We hypothesized that these goals could be achieved by treating patients preoperatively and for 6 months postoperatively with sildenafil, either singly or combined with bosentan. Both drugs have been approved for treatment of PAH on the basis of randomized clinical trials. Preoperative and postoperative (on treatment) hemodynamic evaluation was planned to include noninvasive and invasive diagnostic procedures. As an additional objective, we planned to analyze possible abnormalities in genes that have been shown to be associated with PAH-CHD and inflammatory mediators as well. The idea was to investigate whether changes in these markers correlate with the clinical profile and response to treatments. We shall present preliminary data of 20 patients enrolled so far and discuss the difficulties that we have had with pre- and postoperative management. Further details of the study design may be found in http://www.clinicaltrials.gov, NCT01548950.
M Alhazmi, S Alrawaf, S Mustafa, N Taha, A Alohali, T Kashour
Department of Pulmonary and Critical Care Medicine, King Fahd Medical City, Riyadh, Saudi Arabia
Pulmonary endarterectomy (PEA) is recommended as the treatment of choice for eligible patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, this procedure is only done in a few centers in the world, and not all patients are eligible for this procedure. With the evidence base for significant therapeutic benefits with medical treatment in CTEPH, many experts agree that combinations of prostanoids, endothelin receptor antagonists, and PDE-5 inhibitors will play a major role in therapy. The study was a retrospective observational study performed at King Fahd Medical City. Our objective was to describe the outcome of CTEPH patients when treated with combined medical therapy. We are reporting a case series of 6 patients with confirmed CTEPH treated at KFMC with combined therapy for the time period between 2007 and 2012. Our data describe the clinical presentation, hemodynamics, and radiological findings and the effect of combined therapy on 6-minute walk test and functional class. The duration of follow-up on medical therapy ranged between 2 and 4 years, with improvement in functional class by one class for all 6 patients except case number 3. By 2012, we managed to send 2 patients, namely, case numbers 2 and 3, to the Sulpizio and Papworth medical centers, respectively, for the PEA procedure. Both had successful procedures and did not require pulmonary hypertension medical therapy. In conclusion, the use of combined medical therapy could stabilize patients with CTEPH; however, the risk of decompensation is very high without pulmonary endarterectomy (PEA).