The association of depression at any time to the risk of death following coronary artery disease diagnosis

Aims: Depression is a risk factor for cardiovascular (CV) diseases, incident CV events, and mortality. Among individuals who experience a CV diagnosis or event, whether a subsequent diagnosis of depression is associated with a greater risk of mortality is unknown. Among patients with existing coronary artery disease (CAD), this study evaluated the association of a subsequent depression diagnosis with all-cause mortality.

Methods and results: Patients (N = 24 137) who had angiographically determined CAD (stenosis ≥70%) were studied. Depression after CAD diagnosis was determined by International Classification of Diseases codes and evaluated as a time-varying covariate predicting mortality in multivariable Cox hazard regression models to control for patients' differing lengths of time between CAD diagnosis and depression diagnosis. A total of 3646 (15%) had a depression diagnosis during follow-up. Compared with those without depression, these patients were significantly younger (64 ± 12 vs. 65 ± 12 years), more often female (37% vs. 24%), diabetic (40% vs. 30%), previously diagnosed with depression (26% vs. 5%), and less likely to present with an myocardial infarction (MI) (28% vs. 36%). Death (mean follow-up: 9.7 ± 6.1 years) occurred in 40% of patients (depression: 50% vs. no depression: 38%, P < 0.0001). After adjustment, post-CAD depression was the strongest predictor of death (HR = 2.00, P < 0.0001). This association persisted among subgroups with no prior depression diagnosis (HR = 2.00, P < 0.0001) and by angiography indication: stable angina (HR = 1.84, P < 0.0001), unstable angina (HR = 2.25, P < 0.0001), and MI (HR = 2.09, P < 0.0001).

Conclusion: A depression diagnosis at any time following CAD diagnosis was associated with a two-fold higher risk of death.