Abstract
Authors will present posters based on the following abstracts at the SVM 2012 Scientific Sessions & Annual Meeting. The poster sessions will be at 3:15 p.m., Thursday, June 14, 2012, at the Hyatt Regency Minneapolis, Minneapolis, Minnesota, USA.
In honor of Jay D. Coffman (1928–2006), distinguished internist and researcher of vascular medicine and clinical cardiology, SVM sponsors an annual award in vascular medicine and biology research. The top finalists will make oral presentations based on their posters at the meeting during Session 4: Jay D. Coffman Young Investigator Presentations Luncheon, 11:35 a.m., Thursday, June 14, 2012, at the Hyatt Regency Minneapolis, Minneapolis, Minnesota, USA.
The winners of the Jay D. Coffman Young Investigator Award will be announced during Session 8: Award Presentations, 8:50 a.m., Friday, June 15, 2012, at the Hyatt Regency Minneapolis, Minneapolis, Minnesota, USA.
For more information about the meeting, see the SVM web site, www.vascularmed.org/annual_meeting.
Poster abstracts are organized by category.
Basic science – Cerebrovascular disease and stroke
Poster 1
Stroke in the young: Spontaneous intracranial arterial dissection
Solita V Abesamis
St Luke’s Medical Center, Quezon City, Philippines, Quezon City, Philippines
Intracranial arterial dissection and its associated branch vessels particularly isolated middle cerebral artery dissection has rarely been encountered clinically in otherwise healthy young individuals. It can cause severely disabling ischemic stroke with or without subarachnoid hemorrhage (SAH) and often associated with high mortality rates.
Our patient is a right-handed 16-year-old male presented with sudden loss of consciousness and right-sided weakness. There was no antecedent illness or trauma. Cranial computed tomography scan was unremarkable. EEG showed presence of slower background activity on the left hemisphere indicative of left hemispheric dysfunction of non-specific etiology but absence of clinical/electrographic seizures. A cranial magnetic resonance imaging seizure protocol was done revealing an acute infarct on the left middle cerebral artery with hemorrhagic conversion in the left lentiform nuclei. Carotid duplex scan was unremarkable while transcranial color coded Doppler study revealed less than 50% stenosis in the right proximal MCA and greater than 50% stenosis in the left distal MCA. Systemic connective tissue, cardiac, hematologic disorders, and infectious causes were excluded. Further evaluation showed absence of microembolic signals on TCD bubble test. Diagnostic trans-esophageal echocardiogram showed a small patent foramen ovale. A cerebral angiography was done revealing left proximal MCA long segment dissection with significant flow effect and with suspicious dissection in the left supraclinoid internal carotid artery. Patient was managed with antiplatelet therapy.
Spontaneous intracranial arterial dissection especially in young healthy patients although uncommon, has been recognized as an important cause of stroke and should be considered in the differential diagnosis of intracranial stenosis. Angiography remains the definitive procedure in childhood stroke.
Basic science – Imaging
Poster 2
Ultrasound evaluation in B-mode of native internal arteriovenous fistula maturity by determining the intima–media thickness
Iker Leon, Pedro Manuel Cordova
Hospital Adolfo Lopez Mateos ISSSTE, Mexico City, Mexico
Background: The National Kidney Foundation Dialysis Outcome Quality Initiative (DOQI) guidelines recommend placement of native arteriovenous fistulas in patients undergoing hemodialysis since the diagnosis of chronic renal disease and the creatinine depuration is below 30 ml/min. Surgical creation, of arteriovenous fistulas typically require several weeks of maturation for the vein to dilate and be ready to be punctured. Many fistulas (28–53%) never mature adequately to be usable for dialysis, and there are few reliable methods to evaluate the maturity of the arteriovenous fistula. We propose that ultrasound is an excellent modality for hemodialysis access evaluation, as it is readily available, noninvasive, and inexpensive.
Methods: A randomized trial was done with 20 patients after native fistula was surgically created; we realized ultrasound check every week until they could be hemodyalized with their new fistula. As the minimum distance between two needles for hemodialysis is 5 cm, we measured the intimae–media thickness 3 cm and 8 cm after the arteriovenous anastomosis with multi-frequency ultrasound 7.5 MHz at B-mode until the fistula was mature.
Results: In our experience, the native fistula is mature when the intimae–media thickness is 0.5 mm or larger. This thickness is adequate, regardless of other patient factors (diabetes, hypertension, smoking, age, gender), time to maturation and other variables (type of surgical technique and type of fistula). We could evaluate our patient’s fistulas with ultrasound and send them to hemodialysis when they have their mature native arteriovenous fistula, and if the fistula doesn’t mature we looked for another vascular access before native arteriovenous fistula failure.
Clinical science/epidemiology – Arterial and aortic disease
Poster 3
Impaired walking time in PAD and claudication is associated with peripheral blood monocyte expression of TNFα and serum levels of inflammatory biomarkers
Reena L Pande, Jonathan Brown, Stewart Buck, Whitney Redline, Jorge Plutzky, Mark A Creager
Brigham and Women’s Hospital, Boston, MA, United States
Background: Inflammation contributes to the pathobiology of atherosclerosis in patients with peripheral artery disease (PAD) and also may contribute to the pathophysiology of intermittent claudication (IC) by adversely affecting vascular and skeletal muscle function. We sought to explore the effect of inflammation on walking time in PAD patients with claudication.
Methods: We studied 75 subjects with PAD and stable IC, as well as 43 age-matched healthy subjects. Circulating inflammatory biomarkers measured included tumor necrosis factor α (TNFα), C-reactive protein (CRP), interleukin-6 (IL-6), and soluble intercellular adhesion molecule-1 (sICAM-1). Real-time PCR was used to quantify mRNA from peripheral blood monocytes for genes related to inflammation including TNFα, IFNγ, and CD-36. In PAD subjects, treadmill exercise testing was performed using the modified Gardner protocol.
Results: PAD subjects had significantly higher levels circulating biomarkers compared to healthy subjects, including TNFα (median 2499 [2055, 3405] vs. 1831 [1582, 2184], p < 0.0001), CRP (2.49 [IQR 1.01, 4.81] vs. 1.41 [0.7, 2.42], p = 0.003), sICAM (257.8 [216, 306] vs. 195.4 [171.5, 222.3], p < 0.0001), and IL-6 (2.87 [1.6, 3.7] vs. 1.11 [0.86, 1.7], p < 0.0001). Higher gene expression of TNFα (Figure A) was significantly associated with impaired maximal walking time (MWT), p = 0.01. Impaired MWT was also significantly associated with greater levels of circulating TNFα (p = 0.028; Figure B) and CRP (p = 0.024).
Conclusions: Among patients with PAD and claudication, systemic inflammation, as indicated by inflammatory gene expression in peripheral blood monocytes and by circulating biomarker levels, is associated with greater impairment in walking time.
Poster 4
Concomitant coronary artery disease in patients with premature peripheral artery disease: Gender-specific characteristics and differences
Hamza Rana, Jeanette S Andrews, Kimberley J Hansen, Pavel J Levy
Wake Forest Baptist Medical Center, Winston-Salem, NC, United States
Objective: Coronary artery disease (CAD) is prevalent in patients with premature peripheral artery disease (PAD). We studied gender-specific characteristics and predictors of CAD in younger adults with severe PAD.
Methods: A retrospective, case–control study was conducted in patients ≤ 55 years of age (mean 49.36 ± 6.45 yrs) with symptomatic lower extremity atherosclerotic PAD treated between 1998–2010. CAD was defined by documented coronary events and/or prior coronary revascularization. Data was collected at the initial evaluation for PAD care.
Results: Among 561 PAD patients (46% female), 174 (31%) had concomitant CAD – 82 (47%) females and 92 males. When compared to patients without CAD, both female and male patients with CAD had greater frequency of hypertension, hyperlipidemia, diabetes, family history of premature CAD (FHx CAD) (p < 0.05 for each parameter); female patients had more prevalent polyvascular disease (i.e. cerebrovascular [CeVD] (p < 0.001), renovascular (p = 0.019) and mesenteric (p < 0.01)). In female patients, multivariable logistic regression modeling showed higher odds of concomitant CAD for patients with hyperlipidemia (OR 3.15; 95% CI 1.46–6.80; p = 0.0034), FHx CAD (OR 2.34; 1.15–4.75; p = 0.01), CeVD (OR 4.14; 2.04–8.40; p < 0.0001), and one pack year in smoking increase (OR 1.02; 1.00–1.03; p = 0.02). For male patients, multivariable regression modeling showed higher odds of CAD in patients with hyperlipidemia (OR 8.28; 3.93–17.43; p < 0.0001) and diabetes (OR 2.45; 1.25–4.79; p < 0.01). Female patients with CAD when compared to males, had greater frequency of CeVD (p = 0.013), renovascular disease (p = 0.04) and depression (p < 0.001) and less frequent isolated infrainguinal PAD (p = 0.04).
Conclusions: In younger PAD patients hyperlipidemia is the only traditional risk factor common to both genders to be significantly associated with prevalent CAD in multivariable models. Among patients with concomitant CAD, female had significantly higher frequency of segmental aorto-iliac PAD, polyvascular disease and psychological factors (i.e. depression).
Poster 5
Functional impairment predicts cardiac and peripheral vascular events in patients with peripheral artery disease
Rebecca M LeLeiko, Robert T Eberhardt, Monika Holbrook, Joseph N Palmisano, Corey E Tabit, Na Wang, Farhana Sharmeen, Abhishek Khemka, Alik Farber, Ashvin N Pande, Joseph A Vita, Naomi M Hamburg
Boston University Medical School, Boston, MA, United States
Peripheral artery disease (PAD) confers high cardiovascular risk. Patients with PAD have accelerated functional decline leading to disability. Functional status has been associated with mortality in PAD. We sought to investigate the relation of functional measures with cardiac and vascular risk in PAD. In a cohort of 301 PAD patients (age 65 ± 10 years, 42% women, 32% black), we assessed functional status using the Walking Impairment Questionnaire and disease severity by ankle–brachial index (ABI). PAD patients were classified based on baseline walking distance. Patients were followed prospectively for two years for the development of clinical events. Cardiac events (myocardial infarction, unstable angina, congestive heart failure, cardiac death) occurred in 41 patients (14%) and peripheral events (critical limb ischemia, amputation, graft or stent failure) occurred in 60 patients (20%) during follow-up. In survival analyses, walking distance was associated with both the risk of cardiac events and peripheral events (log-rank p = 0.0003 and p = 0.009, respectively). In Cox proportional hazard models adjusting for age, gender, ABI, comorbidities, and additional confounders, patients in the poorest baseline tertile of walking distance had higher risk of cardiac events (HR 2.89, 95% CI 1.46, 5.71, p = 0.002) and peripheral events (HR 2.10, 95% CI 1.23, 3.57, p = 0.009) compared with patients with higher baseline walking distance. Our findings demonstrate that functional impairment provides additional prognostic value over ABI regarding the risk of cardiac and peripheral events in patients with PAD. Further studies are warranted to determine whether interventions that improve functional status in PAD will reduce cardiovascular risk.
Poster 6
Utility of claims-based data to identify critical limb ischemia patients
Wobo Bekwelem1, Lindsay G Smith2, Alan T Hirsch1, Niki C Oldenburg1, Tamara J Winden3, Hong H Keo4, Sue Duval1
1University of Minnesota Medical School, Minneapolis, MN, United States; 2Division of Epidemiology & Community Health, University of Minnesota School of Public Health, Minneapolis, MN, United States; 3Allina Hospitals & Clinics, Minneapolis, MN, United States; 4Kantonsspital Aarau AG, Aarau, Switzerland
Background: Administrative data are increasingly being used to identify patients with specific diseases. The utility of this approach varies widely by disease state. No study has determined the validity of using ICD-9 diagnosis and procedure codes from an electronic health record (EHR) billing system to identify patients with critical limb ischemia (CLI).
Methods: Patients diagnosed with CLI (n = 126) by a vascular specialist during a hospital admission were enrolled in a dedicated registry. Patients without CLI in their EHR problem list (n = 252) were frequency matched to CLI patients on age, sex and admission date in a 2:1 ratio. Billing diagnosis and procedure codes for all patients were extracted. Algorithms were developed on the basis of ICD-9 diagnosis and procedure codes using frequency distributions of codes in any position for the cases, and on the basis of clinical knowledge of the condition. The sensitivity, specificity, positive and negative predictive values were calculated for each algorithm.
Results: The sensitivity of the algorithms ranged from 0.29 to 0.92 (Table); the specificity was at least 0.99 for each algorithm. Algorithm 5, based on a combination of diagnosis and procedure codes exhibited the best overall performance with a sensitivity of 0.92, specificity of 0.99, positive predictive value of 0.98, and a negative predictive value of 0.96.
Conclusion: Billing ICD-9 diagnosis and procedure codes can be used effectively and efficiently to identify CLI patients for population-based surveillance, epidemiological studies and recruitment for clinical trials. An algorithm based on a combination of diagnosis and procedure codes has the best utility in identifying these patients.
Algorithms use ICD-9 CM diagnosis and procedure codes.
PPV, positive predictive value; NPV, negative predictive value.
Poster 7
Isolated proximal-without-distal exercise-induced ischemia in patients with borderline or normal ankle to brachial index at rest
Pierre Abraham, Nafi Ouedraogo, Jean Picquet, Georges Lefteriotis
University Hospital, Angers, France
Background: Isolated exercise-induced proximal ischemia is difficult to diagnose. Measurement of transcutaneous oxygen pressure (tcpO2) is of interest to simultaneously record and then differentiate proximal (buttock) from distal (calf) regional blood flow impairment (RBFI) during exercise. We searched for proximal-without-distal RBFI as a possible cause of claudication, in patients with borderline (ABI-b: 0.91–0.99) or normal (ABI-n: 1.00–1.40) ankle to brachial index at rest.
Methods: The tcpO2 on chest, buttocks and calves were recorded during treadmill walking tests (3.2 km/h, 10% slope) in 220 ABI-b and 243 ABI-n different consecutive patients complaining of limiting claudication (each patient’s ABI was the lowest of the two legs). Limiting claudication was defined as the reported inability to walk 1 km without stopping. A DROP index (limb tcpO2-changes minus chest tcpO2-changes from rest) below –15 mmHg was used to indicate a positive result (i.e. exercise-induced RBFI).
Results: Treadmill exercise showed evidence for proximal or distal RBFI, at least on one side, in 128 out of 220 (58.2%) and in 86 out of 243 (35.4%) patients with ABI-b and ABI-n, respectively. Isolated proximal-without-distal RBFI was found in 32 out of the 128 (25.0%) positive tests in ABI-b and 32 out of the 86 (37.2%) positive tests in ABI-n patients.
Conclusions: Isolated proximal-without-distal RBFI, is found in approximately one out of seven patients complaining of symptom-limiting claudication and with a borderline or normal resting ABI. Exercise-tcpO2 may help to discriminate patients with arterial claudication that may benefit from invasive investigations and procedures. Comparison of exercise-tcpO2 to post-exercise ABI in such patients remains to be done.
Poster 8
Higher levels of inflammatory biomarkers are associated with poorer peroneal nerve conduction velocity in patients with PAD
Umberto Campia, Mary McDermott
Northwestern University, Chicago, IL, United States
Background: Individuals with lower extremity peripheral arterial disease (PAD) have higher inflammatory marker levels and greater functional impairment than persons without PAD. Furthermore, people with severe PAD have impaired peroneal nerve function compared to those without PAD. In diabetic patients, subclinical inflammation is associated with polyneuropathy and neuropathic impairment. However, whether in people with PAD higher inflammatory marker levels are associated with poorer lower extremity motor nerve function is unknown.
Methods: Cross sectional study in 423 persons with PAD (ankle–brachial index [ABI] < 0.90). Measured markers included high sensitivity C-reactive protein (CRP), vascular cell adhesion molecule (VCAM), intercellular adhesion molecule (ICAM), interleukin-6 (IL-6), and homocysteine. Lower extremity motor nerve function was assessed using peroneal nerve conduction velocity (NCV) measured by electroneurography.
Results: Adjusting for age, sex, race, smoking, alcohol use, comorbidities (diabetes, disk disease, spinal stenosis and cardiovascular disease), body mass index, and ABI, higher levels of VCAM, IL-6, and homocysteine were associated with lower peroneal NCV (Table). Levels of CRP and ICAM were not associated with peroneal NCV (p = 0.942 and p = 0.113, respectively).
Conclusions: In people with PAD, higher levels of VCAM, IL-6, and homocysteine are associated with lower peroneal NCV, independent of confounders including ABI. In contrast, higher levels of CRP and ICAM are not associated with poorer peroneal NCV. Further studies are needed to determine the mechanisms underlying the associations between these markers and lower extremity motor nerve function in persons with PAD.
Adjusted associations between peroneal nerve conduction velocity and blood markers in persons with PAD
Poster 9
Correlation of segmental pressure index with Doppler signals in an outpatient practice setting
Charlene M McCarter
Mayo Clinic, Rochester, MN, United States
Background: Segmental pressures, including ankle brachial indices, are the mainstay of screening for peripheral vascular diseases. A change in Doppler signals is also noted in this population of patients. The relationship between these two is poorly described.
Methods: We examined a subset of patients from the outpatient setting referred for lower extremity arterial studies. 907 data points from the superficial femoral, posterior tibial and dorsalis pedis were included. Non- and poorly-compressible vessels, absent Doppler signals were excluded. Post-operative patients were included.
Results: The mean indices were as follows:
There was statistical significance between all groups.
Conclusions: The small data set demonstrated a significant correlation between the segmental pressure and the Doppler signal. This suggests that screening continuous wave Doppler would prove a useful tool in those patients with non- or poorly compressible vessels or other circumstances when pressure cannot be obtained. A larger data set of over 50,000 patients is currently being analyzed to confirm this finding.
Poster 10
Anatomic correlates of supranormal ankle brachial indices (ABI)
Ido Weinberg, Jay Giri, Marcella A Calfon, Beau M Hawkins, Mitchell D Weinberg, Robert M Schainfeld, Michael R Jaff
Massachusetts General Hospital, Boston, MA, United States
Background: Supranormal ABI (defined as > 1.4) is associated with increased cardiovascular risk and causes diagnostic challenges. The anatomic distribution of peripheral artery disease (PAD) in patients with supranormal ABI has not been previously described.
Methods: A retrospective review of all patients referred to the Massachusetts General Hospital Vascular Lab from 5/1/2006 – 7/22/2009 who had both a supranormal ABI and contrast arteriography (CA) within 3 months is reported. Fifty-two out of 379 patients with supranormal ABI met these criteria. Angiographic patterns were described by the TASC II classification.
Results: Sixty-one limbs were analyzed in 52 patients. Mean age was 70.7 years (SD = 10.8). 78.8% (41/52) were male; 86.5% (45/52) Caucasian; 67.3% (35/52) diabetic; 78.8% (41/52) hypertensive; 67.3% (35/52) hyperlipidemic; and 61.5% (32/52) current or former smokers. Hemodialysis was required in 26.9% (14/52) of patients. 46.2% (24/52) had intermittent claudication and ischemic ulcers in 53.8% (28/52). Iliac, superficial femoral and infra-popliteal PAD was found in 14.0% (7/50), 47.2% (27/56) and 87.0% (47/54), respectively (Figure 1). Multilevel disease was present in 36.3% (16/44) of patients. Toe brachial index (TBI) < 0.7 was found in 87.2% (41/47) of patients with CA-defined PAD. Only one patient had a supranormal ABI and TBI (2.1%).
Prevalence of PAD with supranormal ABI. (SFA, superficial femoral artery; Infra-Pop, infra-popliteal distribution.)
Conclusion: In a population of patients with supranormal ABI, there is a high prevalence of CA-defined PAD. One-third had multilevel PAD, and almost 90% had infrapopliteal involvement. A supranormal ABI, therefore, mandates further evaluation.
Poster 11
Results of a biomarker screen to identify peripheral arterial disease
John P Cooke1, William R Hiatt2, Eric Fung3, Gillian Crutcher3, Alan Smith3, Chriss Stanford2, Armen Zakharyan2
1Stanford University School of Med, Stanford, CA, United States; 2University of Colorado, Aurora, CO, United States; 3Vermillion Inc., Fremont, CA, United States
Background: Current guidelines recommend that smokers or diabetics over the age of 50, and all individuals ≥ 65, be screened for PAD. A biomarker index would be useful to raise suspicion of PAD, so as to trigger appropriate vascular testing and management. We hypothesized that a combination of beta2microglobulin (B2M), cystatin C (cysC), and C-reactive protein (CRP) could add predictive value to the Framingham Risk Score (FRS) in detecting PAD.
Methods: This multi-center study enrolled 1025 subjects from primary care clinics who were smokers and/or diabetics ≥ 50y or any individuals ≥ 70y. Subjects underwent a history and vital signs, a fasting blood draw, and an ankle–brachial index (ABI) measurement. PAD was defined as ABI < 0.90 in either leg. Multiple biomarkers and their interactions were evaluated using logistic regression to predict the probability of PAD, starting with univariate analyses of high sensitivity CRP, B2M, cysC, fasting glucose, age and smoking variables. A multivariate model with these variables was developed in a random two-thirds of the evaluable population and validated in the remaining one-third. The results are shown for the entire evaluable population.
Results and Discussion: Of the evaluable subjects (n = 979) PAD was detected in 83 (8.5%). The ROC obtained using the biomarker model had a C-statistic of 0.73 while the FRS had a C-statistic of 0.63. This resulted in the biomarker model having a sensitivity of 83% and specificity of 44% at a cutoff of 0.058 for the markers. Since FRS values > 20% in 10 years indicates a person at high risk for any CV disease including PAD, we focused on FRS scores < 20% as the intended use population for screening. In this subgroup the sensitivity of the test was 85%, specificity 46% and out of a total of 20 patients with PAD, the test identified 17 who would have been missed by clinical assessment alone. These results indicate the biomarker model is a useful adjunctive tool that adds independent value to a clinical risk score in the target population of low to moderate Framingham risk.
Poster 12
PAD screening in primary care setting
Manoj K Dhariwal1, Anthony J Comerota2, David Law1
1ProMedica Heart and Vascular Institute, Toledo, OH, United States; 2ProMedica Heart and Vascular Institute, Toledo, OH, United States
Background: PAD is underdiagnosed and undertreated by primary care physicians (PCP). The objective of this study was to increase the identification and appropriate management of PAD patients in the primary care setting through enhanced collaboration between PCPs and vascular specialists.
Methods: PCPs initiated a pilot PAD screening program based upon patients meeting at least one of the criteria shown in Table 1. These patients underwent a detailed physical examination (absent/diminished pulses, abnormal skin color, poor hair growth, skin temperature/lesions) and filled out a PAD questionnaire. They were then referred to a monthly vascular screening program within the institution; screening outcomes were sent to the PCP.
Results: Between November 2011 and December 2011, 52 patients were identified by PCPs. Of these, 19 (37%) underwent the vascular screening and 6/19 (32%) had an abnormal resting ABI (< 0.96).
Conclusion: In a primary care setting, use of the resting ABI in patients with suspected PAD is low. Development of a system of shared responsibility may help improve adherence to national guidelines.
PAD risk factor criteria
Poster 13
Evaluation, treatment, and pathophysiologic mechanism of vascular claudication in a traumatic transtibial amputee: A case report
Andrew L Murray, David C Morgenroth, Joseph M Czerniecki
University of Washington, Seattle, WA, United States
Claudication, a well described symptom of peripheral arterial disease in non-amputees, has not been described in the residual limbs of transtibial amputees. The pathophysiology of claudication is due to nociceptor stimulation by products of anaerobic metabolism when muscular demand outstrips local oxygen supply. Amputees are susceptible to the same underlying vascular disease process that limits oxygen supply as non-amputees, but residual limb muscles should be relatively spared from anaerobic states since they perform less mechanical work. The prevalence and differential of residual limb pain and the relative unfamiliarity of many providers with amputees can make the diagnosis of residual limb claudication challenging. The case presentation describes a clinical approach to and a proposed pathophysiologic mechanism for claudication in the amputee that differs from the non-amputee. The patient is a 59-year-old man with a right transtibial amputation as a complication of a motor vehicle accident six years prior. On follow-up, he endorsed eight months of new squeezing pain in his residual limb. This was worse after one to two blocks of ambulation and with his prosthesis donned. Pain improved with sitting and doffing his prosthesis. Clinical exam showed a pale, cool residual limb which warmed after doffing the prosthesis. Exam was also notable for non-palpable popliteal and femoral pulses. Multidisciplinary evaluation including CT angiogram of the limb demonstrated multiple occlusive lesions, most severe in the common femoral artery. He underwent thromboendarterectomy and Dacron grafting with palpable intraoperative recovery of his femoral pulse. He was placed on aspirin and clopidogrel post-operatively and he endorsed symptomatic benefit. In the setting of arterial disease, external compression of the limb by the prosthesis may contribute to claudication despite reduced muscular activity in the residual limb.
Poster 14
Prevalence of and risk factors for unfavorable radial artery anatomy prior coronary artery bypass grafting
Syed A Hussain1, Scott M Lilly2, Luis H Eraso3, Sampath Gunda4, Emile R Mohler2
1Wayne State University/Sinai Grace Hospital, Detroit, MI, United States; 2Hospital of the University of Pennsylvania, Philadelphia, PA, United States; 3Thomas Jefferson University Hospital, Philadelphia, PA, United States; 4Hospital of the University of Pennsylvania, Philadelphia, PA, United States
Background: Based on longevity of arterial grafts over venous grafts, the radial artery (RA) is increasingly used for the purpose of coronary artery bypass (CABG). While generally accepted criteria for harvest suggest an RA diameter more than 2 mm and positive Allen’s test with no evidence of calcification, there is little known about the risk factors that determine the presence of these unfavorable RA anatomy findings.
Methods: We performed a retrospective data analysis of 372 patients who underwent RA ultrasound prior to CABG between 2002 and 2011 at a tertiary hospital. RA characteristics and patient demographics were obtained from the ultrasound report and medical record. ANOVA was employed along with chi square and logistic regression to determine relationship between RA characteristics with cardiovascular disease risk factors among other variables.
Results: RA size did not differ bilaterally (mean diameter 0.292 cm ± 0.002), but was larger in males and positively related to body surface area. A history of coronary artery disease, calcium channel blocker (CCB) and beta blocker (BB) use were associated with larger diameters (p < 0.05 for each). The incidence of RA calcification was 17%, and more common in the elderly, diabetics, and among those in the lowest quartile of RA diameter.
Conclusions: RA size varies with respect to gender and body surface area, and medication use. These findings support the practice of preparatory BB and CCB use prior to RA harvest. Moreover, they reveal that RA calcification is a frequent finding among those referred for RA ultrasonography.
Poster 15
Complex vascular access in office-based endovascular procedures
Richard E Stewart, Norma Mejia, Sean Williams, Vinod Kumar
The Heart Center, Bakersfield, CA, United States
Catheter-based endovascular procedures for the management and treatment of peripheral arterial disease have increased in number and complexity. Advances in imaging have made the office-based endovascular laboratory (OBEVL) an attractive option for patient care. However, vascular access to facilitate complex procedures has been limited in this setting. Accordingly, we studied the feasibility of complex vascular access to treat chronic total occlusions of the superficial femoral artery (CTO-SFA) in the OBEVL (GE OEC9900 Elite). Eight patients (5M, 3F, 68 yrs) underwent revascularization via the popliteal (5 patients) and antegrade femoral artery (3 patients) approach. Average length of CTO-SFA was 123 cm and 5/8 vessels were calcified. PTA and stenting was performed in 5 patients, and atherectomy and stenting in 2 patients. Procedural success was in 7/8 patients. Procedure time averaged 78.5 min. Fluoroscopy time was 11.8 min. Contrast vol per intervention was 42 ml.
These preliminary results suggest that complex vascular access to facilitate endovascular treatment of CTO-SFA can be accomplished in the OBEVL setting with acceptable procedure and fluoroscopy times and high success.
Poster 16
Foley catheter use in patients undergoing carotid endarterectomy under general anesthesia
Kuldeep Singh, Jonathan S Deitch, Sean Marco, Jonathan Schor, Charles Sticco
Staten Island University Hospital, Staten Island, NY, United States
Background: This study was undertaken to determine factors contributing to post-operative urinary retention in patients undergoing carotid endarterectomy (CEA) under general anesthesia and to determine the usefulness of preoperative Foley catheterization.
Methods: We reviewed the charts from 2005 to 2010 of patients undergoing CEA under general anesthesia. Patients who had preoperative Foley catheters were compared to those who did not. Exclusion criteria included regional anesthesia, carotid angioplasty/stenting or preoperative renal failure.
Results: 451 patients were included [330 men (73%)]. Preexisting urinary retention existed in 111 patients (25%). 323 (72%) had preoperative Foley catheterization (GROUP 1), of which, 69 patients (21%) developed postoperative urinary retention. Of 128 (28%) patients who did not receive Foleys (GROUP 2), 16 (13%) developed postoperative retention. Groups 1 and 2 were similar in age (71.5 yrs vs. 70.7 yrs, p = 0.37), estimated blood loss (54.6 ml vs. 54.8 ml, p = 0.95), intra-operative fluids given (1402 ml vs. 1485 ml, p = 0.43), history of urinary retention (29% vs. 21%, p = 0.24) and history of BPH (20% vs. 20%, p = 0.90). Patients with preoperative Foley catheterization had a higher incidence of postoperative urinary retention than patients without Foley insertion (21% vs. 13%, p = 0.03), a higher incidence of urinary tract infections (7% vs. 0%), and longer hospital stay (2.18 days vs. 1.66 days). Age over 78 years and intraoperative fluid infusion exceeding 2.6 liters were the only independent risk factor for postoperative urinary retention. A history of BPH or a history of urinary retention did not correlate with postoperative urinary retention.
Conclusion: Foley insertion in patients undergoing CEA may increase the incidence of both postoperative urinary retention and postoperative urinary tract infection, in addition to prolonging hospital stay. Our data supports selective placement of Foley catheters in patients undergoing CEA under general anesthesia.
Poster 17
Aortic stiffness in inflammatory disease states
Hamza A Lodhi, Haroon Chughtai, Syed Ali, Asim Mushtaq, Ali Shafiq, Haris Tasleem, Fahad Younas
St Joseph Mercy Oakland Hospital, Pontiac, MI, United States
Background: Aorta and proximal vessels store about 50% of the left ventricular stroke volume in systole. This volume is essential for adequate organ perfusion during diastole. This character is however lost in arterial stiffness, which is regarded as an independent predictor of stroke and myocardial infarction. Inflammatory diseases have increased mortality secondary to such cardiovascular events. These diseases characterize alterations in physical properties of the vessel walls even in the absence of atherosclerosis. This study is to establish that inflammatory states cause increased aortic stiffness independent of traditional risk factors. We also grouped End Stage Renal Disease along with other inflammatory states with the purpose to devise common treatment guidelines.
Methods: Echocardiographic parameters included: 1. Stiffness index: (Systolic BP/Diastolic BP) / Change in diameter / minimum diameter; 2. Distensibility: Change in diameter / Change in pressure (Systolic BP – Diastolic BP) × minimum diameter; 3. Elastic modulus (inverse of distensibility): Change in pressure (Systolic BP – Diastolic BP) × minimum diameter / Change in diameter.
Results: Aortic sinus strain (p value 0.04) and distensibility (p value 0.03) is decreased in disease group; aortic strain (p value 0.04) and distensibility (p value 0.04) is decreased in disease group.
Conclusion: Reduction in distensibility of the aorta and the aortic sinus represent elevated arterial stiffness, causing increased cardiac events independent of traditional risk factors. Similar to DM and CAD, clear LDL and blood pressure recommendations are needed for patients with inflammatory diseases.
Poster 18
‘The First Encounter’ – A case report of transplant renal artery stenosis
Solita V Abesamis
St Luke’s Medical Center, Quezon City, Philippines, Quezon City, Philippines
Transplant renal artery stenosis is a rare disease and is a commonly missed but potentially treatable complication. It is the most common vascular complication that follows renal transplantation. It is a recognized complication resulting in post-transplant hypertension associated with allograft dysfunction that adversely affects graft survival and prognosis. This complication is potentially treatable if only diagnosed early.
Transplant renal artery stenosis is a clinical condition wherein prompt diagnosis and management must be made because a delay may cause clinical deterioration and graft loss. Currently there are only few international data on TRAS. This study aims to be aware that transplant renal artery stenosis is not only a disease for the nephrologist and transplant surgeon but also a disease that involves cardiologists. Awareness of this disease may one day save our patient from a catastrophic loss of allograft kidney.
This is a case of a 33-year-old male who is a diagnosed case of chronic graft rejection s/p kidney transplant cadaveric (2011) and living donor (1998) secondary to chronic glomerulonephritis. Immediately after the transplant (2011) there was a sudden drop on his creatinine level and blood pressure (BP) was controlled. However, few days after, his creatinine and BP started to elevate. His medications were adjusted which afforded transient improvement. He then deteriorated clinically. Renal Allograft Duplex Scan showed severe stenosis (60% to 99% stenosis) in the distal segment of the renal allograft artery. Biopsy of the allograft kidney revealed borderline changes suspicious for acute rejection, focal C4d staining in peritubular capillaries of undetermined significance, acute tubular injury and moderate interstitial fibrosis and tubular atrophy. He then underwent renal allograft angiogram, which revealed severe distal renal allograft artery stenosis and subsequently performed angioplasty with stenting. Condition improved with a dramatic drop on his blood pressure and creatinine level.
Clinical science/epidemiology – Exercise physiology
Poster 19
Aerobic arm exercise training to improve outcomes for patients with severe claudication and ischemic rest pain
Diane J Treat-Jacobson1, Ulf G Bronas1, Benjamin J Krause1, Carolyn A Robinson2, Steven M Santilli1, Arthur S Leon1
1University of Minnesota, Minneapolis, MN, United States; 2VA Medical Center, Minneapolis, MN, United States
Background: Patients with severe PAD are often unable to engage in walking exercise due to severe activity-induced ischemic pain. We have previously demonstrated that arm ergometry (AE) improved walking distance in patients with mild to moderate claudication. The efficacy of AE to improve limb and functional outcomes has not been demonstrated in patients with severe PAD (ABI < 0.05).
Purpose: (1) Determine the feasibility and tolerability of an AE exercise training program and (2) determine the effect of supervised AE to improve foot tissue oxygenation, walking distance, pain, and QL in patients with severe claudication or ischemic rest pain.
Methods: Participants were assessed before and after a 12-week progressive, 3×/week, supervised AE exercise training program. Outcomes included seated and supine TCpO2, treadmill walking distance (1 mph, 0% grade), VO2, pain (Brief Pain Inventory), health status (SF-36), and QL (PAD Quality of Life Questionnaire; PADQOL). Total accumulated supervised exercise metabolic equivalents (METs) were calculated. Paired t-tests were used to determine change over time in all variables.
Results: Participants (n = 12) were predominantly male, age
Discussion: Results of this pilot study indicate that AE is a feasible option for patients with severe PAD. AE may improve TCpO2, walking distance, pain, and QL. AE may offer an exciting new approach for therapeutic exercise in this population whose claudication limits their ability to exercise. Confirmation of these findings is planned in a larger, randomized, controlled, trial.
Physiological, functional, and quality of life variables at baseline and 12 weeks
Poster 20
Exercise capacity is the strongest predictor of mortality in patients with peripheral arterial disease
Margaret Zhou, Nicholas J Leeper, Kevin T Nead, Arshiya Syed, Joshua Abella, Yoko Kojima, Shyam N Panchal, John P Cooke, Jonathan Myers
Stanford University, Palo Alto, CA, United States
Background: Peripheral arterial disease (PAD) affects ~ 8 million Americans and is associated with significantly impaired survival. PAD shares many epidemiological risk factors with other atherosclerotic conditions, yet prognostic markers of mortality specific to PAD patients are incompletely described. It seems likely, but is not known, that exercise capacity is a prognostic indicator in patients with PAD. Accordingly, we assessed the predictive value of exercise capacity in PAD.
Methods and Results: 725 PAD patients referred for exercise stress testing at the Palo Alto Veterans Hospital between 1987 and 2010 were enrolled and subjected to a customized symptom-limited ramp treadmill protocol. During a median follow up of 7.5 ± 4.7 years, there were 284 deaths. Baseline exercise capacity was 6.7 ± 2.6 METs among survivors and 5.5 ± 2.5 METs in those who died (p < 0.001). Although several physiologic parameters differed between survivors and non-survivors, age-adjusted Cox regression revealed that exercise capacity was the strongest independent predictor of mortality. Each MET was associated with a 16% reduction in all-cause and a 19% reduction CV mortality (p < 0.001 for both). This variable surpassed all classical risk factors (including smoking and gender) as well as all measured exercise test responses (including maximal heart rate and ECG abnormalities).
Conclusions: Amongst PAD patients, reduced exercise capacity is the most powerful harbinger of long-term mortality. This factor has predictive power beyond traditional risk factors and confirms the critical importance of fitness in this cohort. Though not directly tested here, these findings support the concept that exercise therapy may be particularly beneficial in PAD patients.
Clinical science/epidemiology – Imaging
Poster 21
Postprandial effects on arterial stiffness measures in young adults
Eric Y Yang1, Tyler O Murray1, Rita Jermyn2, Gerd Brunner1, Salim S Virani3, Arunima Misra1, Nasser Lakkis1, Addison A Taylor3, Craig J Hartley1, Joel D Morrisett1, Christie M Ballantyne1, Vijay Nambi1
1Baylor College of Medicine, Houston, TX, United States; 2Stony Brook University Medical Center, New York, NY, United States; 3Michael E DeBakey Veterans Affairs Medical Center, Houston, TX, United States
Background: Acute changes on local, as opposed to regional, arterial stiffness measures are unknown following oral intake. Therefore, we assessed arterial function in young healthy adults before and after ingestion of a small fat load using measures obtained with carotid ultrasound (CUS) with speckle tracking and arterial tonometry.
Methods: Healthy young adults (n = 19; 47% women; mean age 25.6 [standard deviation (SD) 6.06] years; mean body mass index 21.4 [SD 2.5] kg/m2) without hypertension, diabetes, dyslipidemias and tobacco use were recruited. All studies were conducted in the morning after a minimum 8-hour period free from food, alcohol, caffeine and other vasoactive substances. Arterial function and time intervals were assessed using bilateral CUS scans and arterial tonometry before and 2 hours after a small meal (450 calories, 27 g total fat, 10 g saturated fat). Only global and mean far carotid walls were examined on CUS due to anterior probe pressure on the near wall.
Results: Peripheral and central systolic and diastolic BP were lower 2 hours after intake of a small meal (Table). The arterial distension period shortened in the mean far carotid wall (Table). Although not significant, a similar trend was seen for the same parameter in the global net carotid wall and for peak carotid strain time in both the mean far and global net carotid wall (Table).
Conclusion: Left ventricular ejection times have been shown to decrease postprandially. In this study, we observed postprandial changes in carotid systolic time intervals on ultrasound with speckle-tracking, likely reflecting physiologic changes in cardiac function. Based on these results, prandial state may affect time-dependent functional measures on carotid vascular exams.
*Hemodynamic and arterial functional parameters pre- and 2 hours post-ingestion of a small meal
All values are mean (standard deviation).
BP = blood pressure.
Ep = pressure strain modulus = central pulse pressure / carotid strain.
Augmentation index = percent by which the forward arterial pressure wave is augmented by the returning reflected arterial pressure wave.
Pre-ejection period = interval between onset of QRS complex on ECG and initial rise in carotid strain value.
Peak Carotid Strain Time = interval between onset of QRS complex on ECG and peak carotid strain value.
Arterial Distension Period = interval between initial rise in carotid strain value and peak carotid strain value.
Clinical science/epidemiology – Lymphology and lymphatic disease
Poster 22
Sensitivity and specificity of fluorescence microlymphography for detecting lymphedema of the lower extremity
H Hong Keo1, Marianne Schilling2, Ernst Groechenig1, Silvia B Gretener2
1Kantonsspital Aarau, Aarau, Switzerland; 2University Hospital Bern, Inselspital, Swiss Cardiovascular Center, Bern, Switzerland
Background: Lymphedema is a chronic, debilitating and common but unrecognized condition. Fluorescence microlymphography (FML) is an almost atraumatic technique used to visualize the lymphatic capillaries. A maximum spread of lymphatic capillaries of ≥ 12 mm is suggested for the diagnosis of lymphedema. Our aim was to assess the sensitivity, specificity, positive and negative likelihood ratios (LR+, LR–) of FML in patients with lymphedema.
Methods: Patients with lower extremity swelling were clinically assessed for lymphedema according to the criteria of the UK Lymphedema Framework. Duplex ultrasound was used to assess venous insufficiency and FML was performed in the affected limb of all patients and maximum spread of lymphatic capillaries was measured. Receiver operator characteristics (ROC) analysis was performed to assess possible threshold values that predict lymphedema.
Results: From 03/2008 to 08/2011 a total of 171 patients with 184 legs and median age of 43.5 (IQR 24, 54) years were assessed. Lymphedema was diagnosed in 94 (51.1%) legs. Sensitivity and specificity of the 12 mm cutoff value was 87% and 64% with LR+ and LR– of 2.45 and 0.20. The 14 mm spread is the overall cutoff value of FML that was associated with 79% sensitivity and 83% specificity, 4.72 LR+ and 0.26 LR– for detecting lymphedema. The positive and negative predictive value was 83% and 79%. The area under the ROC curve was 0.82 (95% CI, 0.76, 0.88).
Conclusion: FML is an expedient additional diagnostic tool for assessing lymphedema with a high sensitivity but low specificity for the actual cutoff value of ≥ 12 mm. A higher cutoff value of ≥ 14 mm has a high sensitivity and high specificity of detecting lymphedema and should be chosen.
Clinical science/epidemiology – Metabolism and endocrine
Poster 23
Single dose extended-release niacin acutely attenuates HDL reduction in the setting of experimental oral fat challenge: A possible role of ANGPTL-3 and CETP modulation
Mohammed Haris U Usman1, Kazuhiro Nakaya1, Arman Qamar1, Ramprasad Gadi2, Grace A Nathanson1, Prabhjot S Nijjar3, Megan Wolfe1, Daniel J Rader1, Richard L Dunbar1
1University of Pennsylvania, Philadelphia, PA, United States; 2Albert Einstein Health Care Network, Philadelphia, PA, United States; 3University of Minnesota, Minneapolis, MN, United States
Background: High density lipoprotein (HDL-c) levels are inversely correlated with the development of atherosclerosis and are reduced postprandially. Niacin elevates fasting HDL-c but the mechanisms are not fully elucidated, and its effects on postprandial HDL-c are largely unknown.
Aim: To determine whether a single dose ER niacin before a fat challenge acutely attenuates the postprandial drop in HDL-c compared to placebo, and to determine mechanisms.
Method: Two postprandial studies in healthy volunteers: 1. A double-blinded, placebo-controlled, random-order crossover experiment comparing 2 grams of ER niacin to matching placebo; and 2. Open-label administration of 1 gram of ER niacin compared to a fat load without niacin. Study drug was administered 1 hour prior to an oral fat load of heavy cream followed by serial plasma sampling for triglyceride (TG), apolipoprotein A-1 (Apo A-1), ANGPTL3, and CETP mass and activity, and HDL-c over 12 hours. Data are expressed as means (95% CI) for incremental (iAUC) or total (tAUC) area under the curve.
Results: Study 1 involved 304 fat challenges in 152 subjects. HDL-c dropped after the fat load, with an iAUC of –71.9 mg/dL*h (–65.1 to –78.6), whereas 1 gram ER niacin reduced the drop to –32.5 mg/dL*h (25.6 to –39.3) a 55% difference (p < 0.00001). In Study 2, 2 grams ER niacin mitigated the drop in HDLc more effectively: the iAUC was –19.0 (–35.7 to –2.3) on placebo vs. –2.1 (–18.8 to +14.6) mg/dL*h on niacin, an 89% difference (p = 0.047). ANGPTL3 iAUC was +2206 ng/mL*h (+1811 to +2602) on placebo vs. +2560 ng/mL*h (+2165 to +2955) on ER niacin, a 16% rise (p = 0.001). CETP activity decreased from an iAUC of +118.2 nmol/L*h (95% CI +90.5 to +146) to –15.7 nmol/L*h (95% CI –36.4 to +5.1) on niacin, so that the usual postprandial increase in CETP activity was abolished by niacin (p < 0.00001).
Conclusions: HDL-c decreases significantly postprandially. Single dosing with either 1 or 2 grams of ER niacin mitigated this decline. ANGPTL3 elevation and CETP suppression may play a mechanistic role in this process.
Clinical science/epidemiology – Other
Poster 24
Microvascular disease in the elderly: Retinal and renal scans in the cardiovascular health study
Billy G Chacko1, Timothy E Craven2, Hamza Rana1, Matthew S Edwards1, Pavel J Levy1, Kimberley J Hansen1
1Wake Forest University Baptist Medical Center, Winston-Salem, NC, United States; 2Wake Forest University, Winston-Salem, NC, United States
Microvascular disease is increasingly recognized in the elderly. Retinal microvascular changes on photomicrographs are associated with cardiovascular morbidity, mortality, renal functional decline and the pre-hypertensive state. Renal microvascular abnormalities on duplex sonography are also associated with renal functional decline and the pre-hypertensive state. We conducted this study to compare the renal and retinal microvasculature using non-invasive methods.
The Cardiovascular Health Study (CHS) is a prospective, multicenter, cohort study initiated in 1989 to examine cardiovascular risk factors, morbidity and mortality in elderly Americans. A nested subset with both retinal and renal scans was examined to evaluate relationships between central retinal vein equivalent (CRVE) and renal duplex measures. CRVE is a measure of the diameter of the central retinal vein calculated using IVANTM software. CRVE is associated with markers of endothelial dysfunction, clinical and radiographic stroke and change in serum creatinine. Associations were assessed using linear regression analysis-of-covariance (ANCOVA) models. A ‘best’ subset of predictors for CRVE was constructed using backward variable elimination with a 0.10 alpha-level.
A total of 276 participants had comparative retinal and renal data and 25 were excluded due to missing values. RI had the strongest association with CRVE among non-retinal factors: a one SD increase in RI was associated with a –3.36 ± 0.97 unit decrease in CRVE (p = 0.0006), after controlling for CRAE, change in serum creatinine, ankle- brachial index, age, BMI, sex and race. The final model accounted for 45.9% of the variability in CRVE, with CRAE responsible for 33.1%.
The renal resistive index had the strongest association with CRVE after controlling for several covariates. The microcirculation in two anatomically separate regions are strongly related in the healthy elderly.
Poster 25
Ultrasound guidance for combined antegrade and retrograde arterial access in patients with severe infrapopliteal disease and critical limb ischemia
Larry J Diaz-Sandoval, Fadi Saab, Barbara Karenko, Lance Richards, Carmen Heaney, Theresa Laeder, Jihad A Mustapha
Metro Health Hospital, Wyoming, MI, United States
Background: Patients with severe below-the-knee (BTK) peripheral artery disease (PAD) and critical limb ischemia (CLI) derive improved outcomes when treated with current endovascular therapies. Benefits range from reduction in symptoms and improved ulcer healing to amputation prevention. Successful and adequate combined antegrade femoral and retrograde tibio-pedal arterial access is one of the cornerstones of this approach at our institution. We hypothesized that the routine use of ultrasound (US) guidance should maximize success while minimizing complications related to this technique.
Methods: We conducted a retrospective analysis of 29 consecutive patients (73 lesions) with Rutherford IV–VI, with severe BTK PAD, admitted to our institution between 2010 and 2011. US guidance was used to access the vascular bed in combined antegrade and retrograde fashion.
Results: US guidance allowed successful combined arterial access in 96.55% of the cases (28/29). The average time to access was 4.74 ± 1.2 min. 72.4% of cases (21) were elective and 27.6% (8) were urgent. Procedural success was achieved in 100% of the cases: 38.4% AT, 20.5% of each PT, Peroneal and TPT. Upon discharge, and at 30 days, there were no amputations. There were no access-related complications in any of the patients in this series. Symptom improvement was reported in 50% of patients. There was no target lesion revascularization.
Conclusion: US guidance is a feasible, rapid, safe and reproducible technique that facilitates arterial access in patients with CLI & severe BTK PAD, whether they present in elective or urgent circumstances. Standard application of US guidance, as well as of the combined arterial access technique, is recommended to treat severe BTK PAD in patients with Rutherford IV–VI in order to improve symptoms and procedural success, prevent amputations and avoid immediate and 30-day arterial access site complications.
Clinical science/epidemiology – Thrombosis and hemostasis
Poster 26
High prevalence of present-on-admission DVT among patients transferred to a tertiary cardiovascular center may lead to over reporting of adverse quality indicators
Aditya M Sharma, Ruchi Sanghani, Jeevanantham Rajeswaran, John Bartholomew, Eugene Blackstone, Daniel Clair, Christina Doehring, Pamela Goepfarth, Alia Grattan, Umesh Khot, Bruce Lytle, Steven Nissen, Shannon Phillips, Joseph Sabik, Jiansheng Zhong, Heather L Gornik
Cleveland Clinic Foundation, Cleveland, OH, United States
Introduction: Venous thromboembolism (VTE) is a leading cause of preventable death among hospitalized patients. Regulatory agencies have recognized hospital acquired VTE as an important quality indicator with implications for public reporting and reimbursement. As major referral centers accept a significant volume of patients from other hospitals, it is possible that VTE event rates may include abnormalities that developed during the outside hospital stay (i.e. were present on admission, POA). We sought to determine the prevalence and risk factors of POA deep vein thrombosis (DVT) among hospital transfer patients.
Methods: Consecutive patients transferred to the Heart and Vascular Institute of a tertiary care medical center between 11/15/2011 and 12/15/2011 underwent clinical DVT risk assessment using validated tools followed by venous duplex ultrasound (DUS) of lower extremities (LE) within 48 hours of transfer. Patients with intermediate or high risk score for upper extremity (UE) DVT also underwent UE DUS.
Results: 371 hospital transfer patients were evaluated, of which 330 (88.9%) underwent both clinical assessment and DUS. Mean age was 64.8 ± 15.9 years and 60.9% were males. Mean length of hospital stay (LOS) prior to transfer was 3.0 ± 9.0 days and median LOS was 1 day [IQR-2]. 40.0% were transferred to an ICU, 7.8% had undergone major surgery within the prior 14 days and 14.5% had a history of prior VTE. DUS examinations findings are shown in the Table below; the prevalence of LE DVT was 10.3% and 16.9% patients referred for UE DUS had DVT. Risk factors for POA LE DVT were advanced age, longer LOS prior to transfer, history of VTE, bedridden ≥ 3 days or recent major surgery, leg edema and higher Well’s criteria scores.
Conclusion: There is an unexpectedly high prevalence of POA DVT among cardiovascular patients transferred to a tertiary care center. These findings suggest over reporting of hospital acquired DVT among tertiary care centers which receive a significant volume of hospital transfers.
DVT findings of acute or age-indeterminate DVT with anatomical location consistent with AHRQ PSI-12 quality indicator.
Poster 27
Patients with DVT or PE have a high likelihood of hypercoagulable disorders
Charudatta Bavare, Tiffany Street, Jean Bismuth, Hosam El-Sayed, Eric Peden, Alan Lumsden, Mark Davies, Joseph Naoum
The Methodist Hospital, Houston, TX, United States
Background: Hypercoagulable disorders can lead to deep vein thrombosis (DVT) and venous thromboembolism (VTE). Patients at risk for a hypercoagulable vascular event have been underestimated and identifying those patients can be important for their management.
Methods: We reviewed clinical data on 18 consecutive patients. A hypercoagulable workup was performed in all patients who presented with a history of DVT and/or pulmonary embolus (PE). Relevant clinical variables were analyzed.
Results: Eleven women and seven men (age 49 ± 17 years, range 16–79 years) had one of the defined conditions and underwent a hypercoagulable evaluation. Eighty-nine percent of patients had DVT, 28% had PE, and 17% presented with both. Fourteen patients (78%) had an abnormal hypercoagulable profile, eight patients had only one abnormality, three patients had 3, two patients had 5, and one patient had 6 abnormal values, respectively. A hypercoagulable state was present in 81% of patients with DVT only, 78% of patients with either DVT or PE, 67% of patients with DVT and PE, and 40% of patients with PE only, respectively. An elevated homocysteine level was present in 44% of patients; lupus anticoagulant was present in 33%, functional protein C deficiency in 28%, functional protein S deficiency in 28%, antithrombin III deficiency in 22%, heparin antibodies in 11%, anticardiolipin antibodies in 6%, and Factor V Leiden mutation in 6%, respectively.
Conclusions: Hypercoagulable disorders are not uncommon in patients with DVT and those who suffer from venous thromboembolism. Patients who present with either DVT or PE warrant a hypercoagulable evaluation.
Clinical science/epidemiology – Vascular surgery
Poster 28
Hybrid endovascular exclusion of aberrant right subclavian artery aneurysms
Danielle C Horne, Martin R Back, Murray L Shames
University of South Florida, Tampa, FL, United States
Purpose: As an alternative to open arch reconstruction, we detail an experience with staged transcervical arch branch reconstruction and aortic endograft exclusion of symptomatic aneurysms involving the origin of an aberrant right subclavian artery (ARSA).
Methods: Since 2006, six patients (ages 32–84 years) presented with symptoms of chronic dysphagia (n = 5) and acute type B aortic dissection (n = 1) and ARSA (sizes 2.1–6.1cm by CTA). All patients were managed by bilateral common carotid to subclavian artery bypass (n = 9) or transposition (n = 3) with a right to left carotid bypass needed in one case. Left subclavian (n = 6) and carotid (n = 1) origin coverage was required for proximal fixation > 20 mm in the mid arch. Staged (1–5 days) exclusion of the ARSA origin and adjacent arch branches was done via transfemoral access (n = 5) or iliac conduit (n = 1) with short (10–15 cm) single endografts. Open distal ligation (n = 8) or retrograde embolization (n = 4) with vertebral preservation completed exclusion of subclavian vessels.
Results: No mortality, spinal cord ischemia, stroke, upper limb ischemia or wound site complications occurred during follow-up. Length of stay ranged 6–21 days. Dysphagia resolved within days to weeks in each case. Surveillance ranged from 2 to 47 months (mean 29 mo) with three patients followed beyond 3 years. ARSA regression (–4 to –24 mm) was observed in all but one patient (no change) with transcervical bypasses remaining patent and no endoleaks.
Conclusion: By utilizing a hybrid endovascular technique for treating symptomatic ARSA, we have achieved durable repairs and symptom relief.
Poster 29
The cost of major lower limb amputation – A twelve year experience at a UK hospital
Robert W Jordan, Avi Marks, Daniel Higman
University Hospital Coventry & Warwickshire, Birmingham, United Kingdom
Background: The amputee population is elderly and has significant medical co-morbidities. This results in high peri-operative mortality and has financial implications on the health service. Commonly used outcomes in the literature are survival, prosthetic use and mobility. Our study aims to share our 12-year experience of amputee care at our UK centre.
Methods: A retrospective study of 130 amputations performed between January 1998 and December 2009 was performed. Patients were followed up for a mean of three and a half years and analyzed for demographics, vascular history, operation details, prosthetic use and subsequent mobility.
Results: The population was 59.2% male, had a mean age of 73 and the commonest indication for amputation was critical ischaemia (78.5%). The average length of stay was 63 days with a 30-day mortality rate of 15.3% and inpatient mortality of 29.3%. The majority of patients were issued a prosthesis (63.3%) and 48.2% of patients achieved at least indoor mobility, with transtibial (49.9%) rehabilitating better than transfemoral amputees (24.3%).
Conclusion: Our findings highlight that the amputee population has a high peri-operative mortality and urgent action is needed to address this. However we have shown that the majority of survivors at our centre are provided with a prosthesis and around half achieve indoor mobility.
Clinical science/epidemiology – Venous disease
Poster 30
Use of dabigatran in upper extremity deep venous thrombosis following percutaneous endovenous intervention
Mohsen Sharifi1, Kyle Spagnolo2, Roxanne Rea2, Curt Bay2, Muhammad Alam1, Laura Skrocki1
1Arizona Cardiovascular Consultants, Mesa, AZ, United States; 2AT Still University, Mesa, AZ, United States
Background: Symptomatic upper extremity deep venous thrombosis (UEDVT) is usually associated with indwelling endovenous hardware or malignancy. Percutaneous endovenous intervention (PEVI) has been shown to be effective and safe in this setting. Despite the high efficacy of dabigatran in the treatment of venous thromboembolism (VTE), this drug is still not approved for VTE in the US. The role of dabigatran following UEDVT has not been evaluated.
Methods: Eighteen patients with symptomatic UEDVT were placed on dabigatran following PEVI. The dose was 150 mg and 75 mg twice daily in 14 and 4 patients respectively. There were 9 patients with indwelling catheters or leads, 4 with non-malignancy related thrombophilic state, 3 with malignancy and 2 with unknown etiology. Dabigatran was initiated after PEVI. No further parenteral anticoagulation was given when dabigatran was started and hence the traditional recommended 5 days of parenteral anticoagulation was not observed.
Results: The mean follow up was 9 ± 2 months. The UEDVT was occlusive in all patients. PEVI which consisted of thrombolysis, balloon venoplasty and stenting was successful in all. Follow-up venous duplex was obtained at 1 and 6 months. There was no recurrent UEDVT in any patients. The mean duration of parenteral anticoagulation was 40 ± 7 hours. No bleeding was observed with PEVI or at follow-up.
Conclusions: Dabigatran is an effective and safe anticoagulant in patients with UEDVT who undergo PEVI. Furthermore a shorter duration of parenteral anticoagulation may be used in such patients.