Depressive Symptoms and Risk of New Cardiovascular Events or Death in Patients with Myocardial Infarction: A Population-Based Longitudinal Study Examining Health Behaviors and Health Care Interventions

BACKGROUND: Depressive symptoms is associated with adverse cardiovascular outcomes in patients with myocardial infarction (MI), but the underlying mechanisms are unclear and it remains unknown whether subgroups of patients are at a particularly high relative risk of adverse outcomes. We examined the risk of new cardiovascular events and/or death in patients with depressive symptoms following first-time MI taking into account other secondary preventive factors. We further explored whether we could identify subgroups of patients with a particularly high relative risk of adverse outcomes. METHODS AND RESULTS: We conducted a prospective population-based cohort study of 897 patients discharged with first-time MI between 1 January 2009 and 31 December 2009, and followed up until 31 July 2012. Depressive symptoms were found in 18.6% using the Hospital Anxiety and Depression Scale (HADS-D≥8). A total of 239 new cardiovascular events, 95 deaths, and 288 composite events (239 new cardiovascular events and 49 deaths) occurred during 1,975 person-years of follow-up. Event-free survival was evaluated using Cox regression analysis. Compared to the 730 patients without depressive symptoms (HADS-D<8), the 167 patients with depressive symptoms (HADS-D≥8) had age- and sex-adjusted hazard ratios [HR] (95% confidence interval [CI]) of 1.53 (95% CI, 1.14–2.05) for a new cardiovascular event, 3.10 (95% CI, 2.04–4.71) for death and 1.77 (95% CI, 1.36–2.31) for a composite event. The associations were attenuated when adjusted for disease severity, comorbid conditions and physical inactivity; HR = 1.17 (95% CI, 0.85–1.61) for a new cardiovascular event, HR = 2.01 (95% CI, 1.28–3.16) for death, and HR = 1.33 (95% CI, 1.00–1.76) for a composite event. No subgroups of patients had a particularly high risk of adverse outcomes. CONCLUSIONS: Depressive symptoms following first-time MI was an independent prognostic risk factor for death, but not for new cardiovascular events. We found no subgroups of patients with a particularly high relative risk of adverse outcomes.