Trends in chronic ischemic heart disease mortality in patients with interstitial lung disease in the United States from 1999 to 2023

Abstract

Background

Interstitial lung disease (ILD) patients often have comorbid chronic ischemic heart disease (CIHD), which may worsen prognosis. Large-scale studies on long-term CIHD mortality trends in ILD patients are lacking. This study analyzes CIHD-related mortality trends in US adults with ILD from 1999 to 2023.

Methods

CIHD-related mortality data were extracted from the CDC WONDER database for ILD patients aged ≥25 years. International Classification of Diseases, 10th Revision (ICD-10) codes J84.1, J84.8, J84.9 identified ILD, and code I25 identified CIHD. Age-adjusted mortality rates (AAMR), annual percentage change (APC), and average annual percentage change (AAPC) per 100,000 were calculated using Joinpoint regression.

Results

Between 1999 and 2023, there were 92,779 CIHD-related deaths among U.S. decedents with interstitial lung disease (ILD, listed as an underlying or contributing cause of death in death certificates); this accounted for a substantial proportion of cardiovascular-related deaths in this decedent population. The overall AAMR showed a slight upward trend (AAPC=0.51%), but with significant nonlinearity: a decrease from 2003–2018 (APC=-1.29%), increased sharply from 2018 to 2021 (APC = 9.75%), with the increase concentrated during the COVID-19 pandemic years. The age-adjusted mortality rate rose modestly from 1.54 per 100,000 in 2018 to 1.60 in 2019 (+3.9%), then surged to 1.73 in 2020 (+8.1%) and peaked at 1.98 in 2021 (+14.5% from 2020). After 2021, mortality declined to 1.88 in 2023. Mortality was higher in men, non-Hispanic Whites, adults >85 years, and in southern and nonmetropolitan areas. Each subgroup showed a significant increase in mortality during 2020–2021, coinciding with the pandemic, while pre-pandemic trends were more gradual.

Conclusions

CIHD-related mortality in ILD patients showed a fluctuating upward trend over 25 years, with a significant jump during the COVID-19 pandemic. This underscores the systemic impact of public health emergencies on cardiovascular health in vulnerable populations. Cardiovascular risk assessment and management should be integrated into routine ILD care, with tailored strategies for high-risk groups and regions.

Introduction

The comorbidity of Interstitial Lung Disease (ILD) and Chronic Ischemic Heart Disease (CIHD) is increasingly recognized.^1,2 ILD involves pulmonary inflammation and fibrosis, while CIHD results from chronic myocardial ischemia. Their coexistence can worsen patient prognosis. ³ CIHD is often underdiagnosed and undertreated in ILD patients, even in those evaluated for lung transplantation, ⁴ and increases healthcare costs. ⁵ Large-scale epidemiological studies on long-term mortality trends for this comorbidity are scarce. Notably, high-resolution computed tomography (HRCT) performed for ILD evaluation can incidentally detect coronary artery calcification, offering an opportunity for early cardiovascular risk stratification and preventive intervention. This radiological finding further underscores the need to understand the burden of CIHD in the ILD population.

The CDC WONDER database provides comprehensive mortality data, ideal for analyzing long-term trends. ⁶ This study aimed to analyze CIHD mortality trends from 1999 to 2023 in US ILD patients using this database and explore demographic and geographic variations.

Methods

The CDC WONDER database provides mortality data for a wide range of conditions and categories from all 50 states and the District of Columbia. The CDC WONDER Multiple cause of Death database was queried to identify deaths with both ILD and CIHD listed on death certificates within the United States, regardless of whether either was an underlying or contributing cause. ⁷ Individuals younger than 25 years of age were excluded from this analysis because ILD or CIHD onset is rare in this population and may lead to unstable mortality estimates. ⁸ International Classification of Diseases, 10th Revision (ICD-10) codes J84.1, J84.8, J84.9 were used to identify ILD cases, and code I25 was used to identify CIHD cases. We specifically selected chronic ischemic heart disease (I25) rather than acute myocardial infarction codes (I21-I22) because: the study aimed to assess the long-term burden of established coronary disease in ILD patients; I25 codes demonstrate greater temporal stability in death certificate reporting; acute events may be disproportionately influenced by terminal events and short-term care disruptions; and the chronic code better identifies patients with established coronary disease who would benefit from ongoing cardiovascular risk management. The extracted variables included year of death, age group (categorized as 25 to 44, 45 to 54, 55 to 64, 65 to 74, 75 to 84, and 85 years or older), sex, race and ethnic group, census region, state, and urban-rural classification. For urban-rural classification, we used the National Center for Health Statistics (NCHS) 2013 urban-rural classification scheme for counties. Metropolitan areas were defined as counties with populations ≥50,000, further subdivided into large metropolitan (population ≥1 million) and medium/small metropolitan (population 50,000 to 999,999). Nonmetropolitan (rural) areas were defined as counties with population <50,000. ⁹ Regions were divided into Northeast, Midwest, South, and West, as defined by the Census Bureau. Data were collected from multiple places of death, including health care Settings (outpatient, emergency department, inpatient, death on arrival, or unknown status), home, hospice, and nursing home/long-term care.

Age-adjusted mortality rates per 100,000 people (AAMRs) were calculated using the 2000 US standard population to facilitate comparisons across groups and across time. ¹⁰ The Joinpoint Regression software (version 5.4.0.0) of the National Cancer Institute was used to analyze the time trend of AAMR. ¹¹ Joinpoint regression used Monte Carlo permutation test to determine the optimal number of turning points. The 95% confidence intervals for AAMR were calculated using the standard errors provided by Joinpoint regression. Joinpoint regression was selected over age-period-cohort (APC) modeling because our primary objective was to identify discrete time periods with statistically significant changes in mortality trends (inflection points) rather than to decompose effects into age, period, and birth cohort components. Joinpoint regression is particularly well-suited for analyzing temporal trends in public health surveillance data, allowing identification of when significant changes occur without requiring assumptions about the functional form of age, period, and cohort effects. This approach directly addresses our research question of whether CIHD mortality in ILD patients has changed over time and when such changes occurred. The identification of inflection points enables clinicians and policymakers to correlate mortality changes with contemporaneous events and interventions. Annual percent change (APC) and average annual percent change (AAPC) were calculated for each time period and for the entire study period. AAPC and its 95% confidence interval were obtained by weighted average APC. The level of significance was set at p≤0.05, and statistically significant values in the results were indicated by an asterisk (*).

Since this study used publicly available, de-identified aggregated data from the CDC WONDER database, no approval from the institutional review board was required, nor was informed consent needed.

Results

Overall

From 1999 to 2023, there were 92,779 death certificates in the U.S. that listed both chronic ischemic heart disease (CIHD) and interstitial lung disease (ILD) among individuals aged ≥25 years. During this period, the total age-adjusted mortality rate (AAMR) for related deaths fluctuant from 1.65 (95% CI: 1.59 to 1.70) in 1999 to 1.88 (95% CI: 1.83 to 1.93) in 2023, with an average annual percentage change (AAPC) of 0.51 (95% CI: -0.18 to 1.21) (Supplemental Table S1). Piecewise Joinpoint regression analysis showed that AAMR increased from 1999 to 2003, with an annual percentage change (APC) of 1.87 (95%CI: 0.10 to 3.66) *. Then it decreased significantly from 2003 to 2018, APC was -1.29 (95%CI: -1.53 to -1.05) *. Thereafter, it increased sharply from 2018 to 2021, and the APC was as high as 9.75 (95%CI: 4.79-14.95) *. However, the trend turned downward from 2021 to 2023, and the APC was -1.76 (95%CI: -5.85 to 2.52) (Figure 1(a)). Overall, AAMR decreased to the lowest point of 1.47 (95% CI: 1.42–1.52) in 2016, then gradually increased to 1.54 in 2018. A modest increase occurred from 2018 to 2019 (1.54 to 1.60, +3.9%), followed by a sharp rise in 2020 (1.60 to 1.73, +8.1%) and a further substantial increase to a peak of 1.98 in 2021 (+14.5% from 2020). Subsequently, mortality declined to 1.88 in 2023.

Figure 1.

(a) Age-adjusted mortality rate of CIHD in patients with ILD (per 100,000 people); Overall and stratified by gender, 1999-2023 (* indicates that APC is statistically significant) (b). Joinpoint model of CIHD AAMR per 100,000 people in ILD patients, stratified by region, 1999–2023 (*indicates the APC is statistically significant).

Demographic differences

Gender stratified

From 1999 to 2023, CIHD in patients with ILD resulted in 61375 deaths in men (66.1%) and 31404 deaths in women (33.9%) in the United States (Supplemental Table S2).

From 1999 through 2023, the age-adjusted mortality rate (AAMR) for chronic ischemic heart disease (CIHD) related deaths in patients with interstitial lung disease (ILD) is consistently higher in men than in women in the U.S.

For males, the AAMR fluctuant from 2.59 (95%CI: 2.47 to 2.71) in 1999 to 3.10 (95%CI: 2.96 to 3.23) in 2023, and the AAPC was 0.59 (95%CI: -0.14 to 1.33). The APC of AAMR in males from 1999 to 2008 was 0.42 (95%CI: -0.28 to 1.12), while the APC of AAMR in males from 1999 to 2008 was not significant. Then it decreased significantly from 2008 to 2017, APC was -1.76 (95%CI: -2.50 to -1.00). Thereafter, it increased sharply from 2017 to 2021, with APC as high as 7.35 (95%CI: 4.08 to 10.72). However, it turned to a downward trend from 2021 to 2023, but the APC was -1.03 (95%CI: -6.49 to 4.74) (Figure 1(b)).

Among women, the AAMR fluctuant from 1.06 (95%CI: 1.00 to 1.12) in 1999 to 1.00 (95%CI: 0.95 to 1.06) in 2023, and the AAPC was -0.14 (95%CI: -0.78 to 0.51). The APC of AAMR in females was 0.63 (95%CI: -1.63 to 2.94), while the APC of AAMR in females did not change significantly from 1999 to 2004. Then it decreased significantly from 2004 to 2016, APC was -2.90 (95%CI: -3.58 to -2.22). However, it turned to a significant upward trend from 2016 to 2023, with an APC of 4.22 (95%CI: 2.89 to 5.55) (Figure 1(b)).

Race stratified

From 1999 to 2023, there were significant racial differences in the mortality rate of chronic ischemic heart disease (CIHD) among patients with interstitial lung disease (ILD) in the United States, with the highest mortality rate among non-Hispanic whites (Figure 2(a)) (Supplemental Table S3).

Figure 2.

(a) Age-adjusted mortality rate of CIHD in patients with ILD (per 100,000 people); Stratified by race, 1999-2023 (* indicates that APC is statistically significant) (b). Joinpoint model of CIHD AAMR per 100,000 patients in ILD patients stratified by race from 1999 to 2023 (* indicates that APC is statistically significant).

The AAMR of non-Hispanic whites fluctuated from 1.74 (95% CI: 1.68-1.80) in 1999 to 2.13 (95% CI: 2.06-2.19) in 2023 (AAPC=0.78%; 95% CI: 0.04-1.53). Its trend was segmented clearly: it rose from 1999 to 2003 (APC=2.04*; 95%CI: 0.19-3.92), and decreased significantly from 2003 to 2018 (APC=-1.11*; 95%CI: -1.36 to -0.85), then rose sharply from 2018 to 2021 (APC=10.11*; 95%CI: 4.75-15.75), and turned to decline from 2021 to 2023 (APC=-0.82; 95%CI: -5.30-3.87) (Figure 2(b)).

Similar recent upward trends have also been observed in other ethnic groups. The AAMR of non-Hispanic blacks decreased significantly from 1999 to 2016 (APC=-1.77*; 95%CI: -2.68 to -0.85), and then increased significantly from 2016 to 2023 (APC=3.98*; 95%CI: 0.91 to 7.15). Hispanic population decreased significantly from 1999 to 2015 (APC=-2.46*; 95%CI: -3.23 to -1.69), and then rose significantly from 2015 to 2021 (APC=5.67*; 95%CI: 2.17 to 9.28). Other non-Hispanic races also showed a significant upward trend from 2015 to 2023 (APC=3.47*; 95%CI: 1.58-5.40) (Figure 2(b)).

Age group stratified

Between 1999 and 2023, the U.S. showed a significant age gradient in CIHD mortality in patients with ILD. The mortality rate was highest in the ≥85 years old group, and the AAMR increased from 19.04(95CI% 17.72-20.37) to 28.78(95CI% 27.45-30.12) (AAPC=1.33%*). This group increased sharply from 2018 to 2021 (APC=11.75%*).

The AAMR of group aged 75-84 years increased from 9.93(95CI% 9.37-10.49) to 11.63(95CI% 11.14-12.13), and increased significantly from 2018 to 2021 (APC=8.41%*) after decreasing from 2003 to 2018 (APC=-1.27%*).

The AAMR of group aged 65-74 years decreased overall (AAPC=-1.42%*), but increased significantly from 2016 to 2021 (APC=3.49%*). The mortality rates were lower in younger age groups (55-64 years and 45-54 years) and showed no significant upward trend (Figure 3(a) and (b); Supplemental Table S4). There was no significant decline in all age groups after 2021.

Figure 3.

(a) The crude mortality rate per 100,000 people of CIHD in patients with ILD; Stratified by age, 1999-2023 (*indicates that APC is statistically significant) (b). Joinpoint model of CIHD crude mortality per 100,000 people in ILD patients, stratified by age groups, 1999-2023 (*indicates the APC is statistically significant).

Regional variation

Census region-based differences

From 1999 to 2023, there were significant regional differences in CIHD mortality among ILD patients in the United States. The mortality rate remained the highest in the southern region (Figure. 4(a) and (b); Supplemental Table S5).

Figure 4.

(a) Age-adjusted mortality rate of CIHD in patients with ILD (per 100,000 people); Stratified by region, 1999-2023 (* indicates that APC is statistically significant) (b). Joinpoint model of CIHD AAMR per 100,000 people in ILD patients stratified by region from 1999 to 2023 (* indicates that APC is statistically significant).

Southern AAMR from 1.55 (95CI% 1.47 1.62) to 1.95 (95CI% 1.87 2.03) * (AAPC = 0.90%), in 2003-2016 (APC* = - 1.99%), 2016-2021 has risen sharply (APC) = 7.42% *.

Similar trends were observed in both the central and western regions, with significant increases after 2016 and 2017 respectively. The APCs were 3.23% (95CI% 1.06-5.45) and 4.84% (95CI% 3.06-6.64)*.

The northeastern region was the only one showing a downward trend (AAPC=-0.16%), with a significant decline from 2005 to 2018 (APC=-1.97%*), and the upward trend from 2018 to 2021 did not reach statistical significance.

Metropolitan and nonmetropolitan differences

CIHD mortality among patients with ILD in the U.S. remained consistently higher in nonmetropolitan areas than in metropolitan areas between 1999 and 2020 (Figure 5(a) and (b); Supplemental Table S6).

Figure 5.

(a) Age-adjusted mortality rate of CIHD in patients with ILD (per 100,000 people); Stratified by urbanization, 1999-2020 (* indicates that APC is statistically significant) (b). Joinpoint model of CIHD AAMR per 100,000 people in ILD patients, stratified by rural/urban population, 1999–2020 (*indicates the APC is statistically significant).

The AAMR of nonmetropolitan area increased from 1.77 (1.63-1.91) to 2.06(95CI% 1.92-2.20) (AAPC=0.58%). After a significant decrease from 2003 to 2016 (APC=-1.71%*), the AAMR of nonmetropolitan area increased sharply from 2016 to 2020 (APC=4.97%*).

The AAMR of metropolitan area increased slightly from 1.62(95CI% 1.56-1.68) to 1.69(95CI% 1.63-1.74)(AAPC=0.06%), and increased significantly from 2017 to 2020 (APC=5.18%*) after decreasing from 2004 to 2017 (APC=-1.40%*).

Both cities showed significant increases in mortality from 2016 to 2020, with nonmetropolitan area remaining at a consistently high level.

Overall, there are significant differences in the mortality trend among different subgroups. The surge related to the pandemic (2020 - 2021) was most pronounced among the elderly, non-Hispanic whites, and males, but all subgroups experienced a significant increase. The long-term trend (1999 - 2023) shows that non-Hispanic whites were the only racial group with a significant increase in overall mortality, while the mortality rate for the 65 - 74 age group decreased significantly. From a geographical perspective, the absolute mortality rate in the southern region has always been the highest, but the western region experienced the largest increase during the pandemic period. These patterns have identified the key populations that require targeted cardiovascular risk reduction intervention measures for specific groups.

Discussion

We analyzed trends and disparities in chronic ischemic heart disease (CIHD) mortality among U.S. interstitial lung disease (ILD) patients from 1999–2023 using the CDC WONDER database. The overall age-adjusted mortality rate (AAMR) showed a slight, non-significant upward trend with notable nonlinearity: a significant decline from 2003–2018 was followed by a sharp, widespread increase from 2018–2021, and a slight subsequent decline. This fluctuation pattern was consistent across all demographic and geographic subgroups, indicating a broad systematic influence. These may include: temporal changes in cardiovascular risk factor management (e.g., statin use, blood pressure control); evolving clinical practice patterns in ILD management, including increased recognition of cardiovascular comorbidities; healthcare policy changes affecting access to cardiology services; environmental exposures with geographic variation; and most prominently, the disruptive impact of the COVID-19 pandemic on healthcare delivery and direct viral effects on cardiovascular health.

The declining mortality trend from 2003-2018 may also reflect diagnostic changes rather than true improvements in survival. The widespread adoption of high-resolution computed tomography (HRCT) during this period increased detection of milder, subclinical ILD, including cases that might previously have gone undiagnosed. This ‘diagnostic expansion’ could have enlarged the ILD population to include more patients with less severe disease and lower cardiovascular risk, potentially lowering the observed CIHD mortality rate even if individual-level prognosis remained unchanged. Additionally, increased CT imaging may have incidentally identified coronary artery calcification, prompting earlier cardiovascular risk assessment and intervention.

ILD patients are at high risk for cardiovascular complications due to chronic hypoxemia, pulmonary hypertension, systemic inflammation, and shared risk factors like smoking.^12–15 The temporal pattern within 2018–2021 reveals that the mortality increase was not uniform: the pre-pandemic year (2018–2019) saw only a modest 3.9% rise, whereas the pandemic years (2020–2021) witnessed dramatic increases of 8.1% and 14.5% respectively. This sharp acceleration coinciding with the COVID-19 pandemic strongly suggests that SARS-CoV-2 infection and associated healthcare disruptions were major contributors to the excess CIHD mortality in ILD patients. SARS-CoV-2 infection can not only directly cause myocardial injury, acute coronary syndrome, and procoagulant state, but also trigger systemic inflammatory response that may aggravate the existing cardiovascular underlying diseases in patients with ILD.^16–18 In addition, the squeeze on medical resources during the pandemic, delayed treatment of cardiovascular emergencies, and patients avoiding medical care due to fear may have jointly contributed to the sharp increase in CIHD mortality during this period.^19,20 The decline in CIHD mortality from 2021 to 2023, despite the ongoing pandemic, may reflect multiple factors. First, widespread vaccine distribution beginning in early 2021 likely attenuated both SARS-CoV-2 infection severity and its cardiovascular sequelae. Second, clinical management of COVID-19 improved substantially with the introduction of antivirals and immunomodulators. Third, healthcare systems gradually restored non-emergency services, improving management of chronic cardiovascular conditions. Fourth, a ‘harvesting’ effect may have occurred, whereby the most vulnerable ILD patients with advanced cardiopulmonary disease died during the initial pandemic surge, leaving a relatively healthier surviving cohort. These factors collectively may have contributed to the observed mortality decline. Some factors may explain the slight increase in mortality rates observed in certain subgroups before the pandemic. Firstly, over time, the recognition and diagnosis of interstitial lung disease have increased, thanks to a higher level of awareness and the widespread use of CT examinations, which may have expanded the diagnostic population to include older, more comorbid, and higher cardiovascular-risk patients. Secondly, the aging of the US population and the increase in the number of patients with interstitial lung disease may have led to an increase in cardiovascular disease mortality. Thirdly, changes in death certificate coding methods, including more reporting of multiple causes of death, may have increased the confirmation rate of cardiovascular disease deaths in patients with interstitial lung disease. Fourthly, the changing trends in the prevalence of cardiovascular risk factors (obesity, diabetes) among patients with interstitial lung disease over time may have increased the burden of coronary artery disease. Importantly, these pre-pandemic trends were relatively mild compared to the significant increase during 2018-2021, which clearly coincided with the outbreak of the pandemic and cannot be explained by gradual changes in clinical practice or coding.

Several factors may have contributed to the observed mortality decline from 2003 to 2018 and the subsequent trends. First, advances in ILD management during this period, including the introduction of antifibrotic therapies (pirfenidone approved in 2014, nintedanib in 2014 for IPF, later expanded to other fibrosing ILDs), may have improved survival and altered the comorbidity burden. While these drugs primarily slow lung function decline, their impact on cardiovascular outcomes remains uncertain, but improved overall health could indirectly reduce cardiovascular mortality. Second, nationwide improvements in cardiovascular risk factor control—such as increased statin use for secondary prevention, better hypertension management, and declining smoking rates—may have benefited ILD patients, who share common risk factors. Third, the Affordable Care Act (ACA) of 2010 expanded insurance coverage and improved access to preventive cardiovascular services, particularly in states that adopted Medicaid expansion; this could have contributed to the post-2010 mortality decline in some subgroups. However, the effect of ACA may have been uneven across regions, potentially explaining some geographic disparities. Fourth, the widespread adoption of high-resolution computed tomography (HRCT) over the study period led to increased detection of milder, subclinical ILD, thereby expanding the denominator of diagnosed ILD patients to include individuals with lower cardiovascular risk, which could artifactually lower the observed mortality rate even if individual risk remained unchanged. Conversely, the sharp increase during 2018–2021 was likely driven by COVID-19-related mechanisms, as discussed, overshadowing these gradual trends.

Persistent disparities were evident. Non-Hispanic Whites had the highest AAMR and the only significant long-term upward trend. All racial groups experienced a similar pandemic-era spike. Patients aged ≥85 years had the highest absolute mortality and the steepest increase during 2018-2021. Geographically, the South had the highest mortality, while the Northeast saw a decrease. Mortality was consistently higher in nonmetropolitan than metropolitan areas, reflecting disparities in healthcare access and quality. ILD is a complex condition optimally managed at specialized interstitial lung disease centers, which are disproportionately located in urban academic medical centers concentrated in the Northeast and West. Patients in rural and Southern regions may face greater travel distances to access multidisciplinary care teams, including pulmonologists with ILD expertise, cardiologists, and thoracic radiologists. Additionally, geographic variation in the adoption of antifibrotic therapy (pirfenidone, nintedanib) and evidence-based cardiovascular risk reduction strategies may contribute to the observed mortality differences. These structural barriers to specialized care likely exacerbate the cardiovascular disease burden in ILD patients residing in underserved areas.

Our study has several limitations. First, it is based on death certificate data, which may be affected by the change of ICD codes, the accuracy of diagnosis and cause of death reporting. The priority of ILD and CIHD as cause of death reporting may be different. Second, the database lacks clinical information at the individual patient level, such as lung function severity, specific ILD classification, cardiovascular medication history, and comorbidities, so it is not possible to control for these potential confounders. Third, the COVID-19 pandemic may affect CIHD mortality through a variety of direct and indirect mechanisms but may not be adequately documented as a mediator in death certificates, adding complexity to data interpretation. Fourth, the CDC WONDER database lacks granular clinical information, including specific ILD subtypes (e.g., idiopathic pulmonary fibrosis vs. connective tissue disease-associated ILD), disease severity measures (such as pulmonary function tests or radiographic extent), and important risk factors like smoking history. This precludes analysis of how these factors may influence CIHD mortality trends. Fifth, the database does not contain information on medication use, including antifibrotic therapies (pirfenidone, nintedanib) introduced during the study period, or cardiovascular medications (statins, antiplatelet agents, beta-blockers) that could modify mortality risk. Sixth, this study is limited to the United States, and findings may not be generalizable to other countries with different healthcare systems, population demographics, and disease management practices. Seventh, we cannot assess the quality or appropriateness of cardiovascular disease management in ILD patients, including adherence to guideline-directed medical therapy or access to revascularization procedures.

This 25-year analysis underscores the significant impact of public health emergencies on this vulnerable population. Future strategies must integrate systematic cardiovascular risk assessment into standard ILD management and address identified health inequities. Pandemic preparedness plans should include specific cardiovascular protection measures for high-risk groups like ILD patients to ensure continuity of essential care.

Conclusion

Analysis of U.S. data (1999-2023) reveals a slight overall increase in CIHD mortality among ILD patients, marked by significant fluctuations—notably a sharp rise during the COVID-19 pandemic. This pattern was consistent across all demographics, underscoring the systemic impact of public health emergencies. Persistent inequalities were evident, with the highest burden among non-Hispanic Whites, the elderly (>85), and those in the South and rural areas. These findings highlight the need to integrate cardiovascular risk screening into routine ILD care, promote multidisciplinary assessment, and ensure continued access to care for vulnerable populations during public health emergencies.

Supplemental material

Supplemental material - Trends in chronic ischemic heart disease mortality in patients with interstitial lung disease in the United States from 1999 to 2023

Supplemental material for Trends in chronic ischemic heart disease mortality in patients with interstitial lung disease in the United States from 1999 to 2023 by Fan Wu, Yan Xue, Yinfeng Luan, Fengjun Zhang, Xinlai Ma and Wei Zhang in Chronic Respiratory Disease.