Aims: Depression in patients following myocardial infarction (MI) is associated with an increased risk of mortality, but this association may be confounded by cardiac disease severity. We explored the relationship between left ventricular ejection fraction (LVEF) and depression in MI patients.
Methods and results: In the Myocardial Infarction and Depression-Intervention Trial (MIND-IT), 1989 MI patients were assessed for depressive symptoms [Beck Depression Inventory (BDI) t = 0, 3, 6, 9, and 12 months post-MI]. Patients with BDI score > or =10 were assessed for the presence of International Classification of Diseases, 10th revision (ICD-10) depressive disorder (t = 3, 6, 9, and 12 months post-MI). Patients were divided into categories according to their LVEF during hospitalization, i.e. LVEF <30%, LVEF 30-45%, LVEF 45-60%, and LVEF > or = 60%. During hospitalization, presence of depressive symptoms was higher in patients with LV dysfunction. A relationship was found between LVEF and ICD-10 depressive disorder, i.e. a lower LVEF was associated with a higher rate of depression from 3-12 months post-MI (P < 0.01). Levels of LVEF inversely correlated with the BDI score at 3 months post-MI. Associations persisted after adjustment for demographics, risk factors for coronary artery disease, co-morbidity, Killip class, and baseline BDI score.
Conclusion: In MI patients, the rate of depression and the severity of depressive symptoms are significantly related to the severity of LV dysfunction. The association between depression and LV dysfunction must be acknowledged when evaluating the prognostic effects of depression in cardiac patients.