['Depression predicts prognosis in many cardiac conditions, including congestive heart failure (CHF). Despite heightened cardiac risk in patients with comorbid atrial fibrillation (AF) and CHF, depression has not been studied in this group. This substudy, from the AF-CHF Trial of rate- versus rhythm-control strategies, investigated whether depression predicts long-term cardiovascular mortality in patients with left ventricular ejection fraction <or=35%, CHF symptoms, and AF history who receive optimal medical care.', 'Depression symptoms (Beck Depression Inventory-II) were assessed in 974 participants (833 men), with 32.0% showing elevated scores (Beck Depression Inventory-II >or=14). Over a mean follow-up of 39 months, there were 246 cardiovascular deaths (111 presumed arrhythmic; 302 all-cause deaths). Cox proportional hazards models adjusted for other prognostic factors (including age, marital status, cause of CHF, creatinine level, left ventricular ejection fraction, paroxysmal AF, previous AF hospitalization, previous electrical conversion, and baseline medications) showed that elevated depression scores significantly predicted cardiovascular mortality (primary outcome), arrhythmic death, and all-cause mortality. The adjusted hazard ratios were 1.57 (95% confidence interval 1.20 to 2.07, P<0.001), 1.69 (95% confidence interval 1.13 to 2.53, P=0.01), and 1.38 (95% confidence interval 1.07 to 1.77, P=0.01), respectively. The risks associated with depression and marital status were additive, with the highest risk in depressed patients who were unmarried.'] Do elevated depression symptoms predict long-term cardiovascular mortality in patients with atrial fibrillation and heart failure?