Interstitial lung abnormalities, coronary heart disease and mortality

BACKGROUND: Interstitial lung abnormalities (ILA) share common risk factors with coronary heart disease (CHD), including increased age and cigarette smoking; however, the relationship between ILA and CHD has not been well described. METHODS: Participants from the Genetic Epidemiology of Chronic Obstructive Pulmonary Disease study (COPDGene) and Age Gene/Environment Susceptibility (AGES)-Reykjavik studies with ILA assessment, clinical CHD and coronary artery calcium (CAC) data were included. In both cohorts, CHD was defined by clinical history and additionally by CAC >100. Multivariable logistic regression assessed the relationship between ILA and CHD; Cox proportional hazards models were used to assess mortality associated with ILA and CHD. RESULTS: 9% of participants with CHD had ILA in both COPDGene and AGES-Reykjavik. Participants with ILA had increased odds of CHD defined by clinical history in COPDGene (OR 1.6, 95% CI 1.2-2.0; p<0.001) and AGES-Reykjavik (OR 1.6, 95% CI 1.2-2.0; p<0.001); similar results were seen with CAC >100. In both COPDGene and AGES-Reykjavik, participants with both CHD and ILA had a greater risk of death compared to those with CHD but without ILA (HR 2.0, 95% CI 1.4-2.7; p<0.001; and HR 1.3, 95% CI 1.1-1.4; p<0.001, respectively). In AGES-Reykjavik, ILA was associated with an over 9-fold increase in the odds of a respiratory death (OR 9.6, 95% CI 3.2-29.0; p<0.0001) among participants with CHD. CONCLUSION: ILA are a common co-occurrence with CHD and associated with worse mortality, suggesting that ILA are a clinically important comorbidity in patients with CHD.