Somatic depression predicts mortality in chronic heart failure: can this be explained by covarying symptoms of...

Somatic symptoms of depression predict mortality in chronic heart failure (CHF), but symptoms of fatigue that are common to both conditions may confound this association. We therefore examined the contribution of fatigue to the association between somatic depression and increased risk of mortality in patients with CHF.

At baseline, 380 consecutive patients with CHF were assessed for symptoms of depression, exertion fatigue, and general fatigue. Demographic and clinical data were obtained from the patients' medical records or the treating cardiologist. The primary end point was mortality after a median follow-up of 2.3 years (range = 0.15-4.76 years).

At follow-up, 63 patients (16.6%) had died. Exertion fatigue (hazard ratio [HR] = 1.04, 95% confidence interval [CI] = 1.01-1.06, p = .003), not general fatigue, was associated with an increased risk of mortality in CHF. Multivariate Cox regression analysis revealed that somatic symptoms of depression (HR = 1.41, 95% CI = 1.05-1.88, p = .02) were independently associated with increased mortality risk and that this association could not be explained by exertion fatigue (HR = 1.02, 95% CI = 0.97-1.05, p = .31).

The adverse effect of somatic depression on prognosis in CHF was not confounded by exertion fatigue. Behavioral interventions should focus not only on fatigue but also on other somatic manifestations of depression in patients with CHF.