Depression predicts prognosis in many cardiac conditions, including CHF, write Nancy Frasure-Smith, PhD, from the Montreal Heart Institute and Université de Montréal in Canada, and colleagues from the Atrial Fibrillation and Congestive Heart Failure Investigators (AF-CHF).

Despite heightened cardiac risk in patients with comorbid 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 =35%, CHF symptoms, and AF history who receive optimal medical care.

In 974 participants including 833 men who completed a Beck Depression Inventory-II (BDI-II) measuring symptoms of depression, 32.0% had elevated scores (BDI-II = 14). The primary outcome of cardiovascular death occurred in 246 patients over a follow-up of 39 months. Secondary outcomes were presumed arrhythmic deaths (n = 111) and all-cause deaths (n = 302). Cox proportional hazards models were helpful to adjust for prognostic factors including age, marital status, cause of CHF, creatinine level, paroxysmal AF, left ventricular ejection fraction, previous hospitalization for AF, previous electrical conversion, and baseline medications.

After adjustment, elevated depression score was a significant predictor of cardiovascular mortality (adjusted hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.20 – 2.07; P < .001), arrhythmic death (HR, 1.69; 95% CI, 1.13 – 2.53; P = .01), and all-cause mortality (HR, 1.38; 95% CI, 1.07 – 1.77; P = .01). Mortality risks associated with depression and marital status were additive, with the highest risk in unmarried depressed patients.

Elevated depression symptoms are related to cardiovascular mortality even after adjustment for other prognostic indicators in patients with comorbid AF and CHF who receive optimized treatment, the study authors write. Unmarried patients are also at increased risk. Mechanisms and treatment options deserve additional study.

The study limitation include lack of generalizability to all patients with CHF and AF, lack of clinician ratings and reliance on self-report of depression symptoms, and only 1 measurement of depressive symptoms. No data was available on the use of antidepressant medications, and the sample size in most of the participating countries was too small to allow evaluation of country-specific factors.

The American Heart Association recently recommended depression screening in CAD [coronary artery disease] patients to identify those who might benefit from additional evaluation or treatment, and there is evidence that selective serotonin reuptake inhibitor antidepressant medications are as safe and efficacious in CAD patients as in the nonmedically ill, the study authors conclude. In the absence of clinical trials specifically addressing these psychosocial risks among CHF patients with AF, we believe that depression and lack of a marital partner should be considered as risk markers identifying patients who may require additional treatment efforts to manage their cardiac conditions and modify other known risks.