Postmyocardial Infarction Depression as a Modifiable Secondary Prevention Risk Factor

Major depressive disorder is a common and clinically consequential complication following myocardial infarction (MI), affecting approximately one-quarter of patients and occurring at substantially higher rates than in the general population. Beyond its prevalence, post-MI depression independently predicts all-cause mortality, recurrent ischemic events, and hospital readmission, with risk proportional to symptom severity and persistence. Emerging evidence supports a bidirectional brain-heart axis linking depression to adverse cardiovascular outcomes through autonomic dysregulation, systemic inflammation, endothelial dysfunction, platelet activation, metabolic disturbance, and impaired health behaviors. Treatment of post-MI depression consistently improves depressive symptoms and quality of life. Selective serotonin reuptake inhibitors appear safe in appropriately selected cardiac patients, and signals of long-term cardiovascular benefit have been observed in some trials. However, randomized evidence demonstrating definitive reductions in mortality or major adverse cardiovascular events remains limited. Persistent and untreated depression is consistently associated with the worst outcomes, suggesting that durable remission may be necessary to influence long-term prognosis. Cardiac rehabilitation provides a critical interface between mental health and cardiovascular recovery, yet depression impairs rehabilitation participation while rehabilitation itself reduces depressive symptoms and improves survival. Integrating longitudinal depression screening, stepped-care treatment pathways, and collaborative care models into established secondary prevention frameworks may enhance both psychological and cardiovascular outcomes. Reframing post-MI depression as a modifiable secondary prevention risk factor supports its systematic incorporation into comprehensive cardiovascular care.