Although it has been established that depression is a risk factor in patients with coronary heart disease, its effect on patients with heart failure is not as clear. A prospective, observational follow-up study of 204 outpatients with heart failure and symptoms of depression was conducted over a median period of three years to evaluate an association between the two conditions.

Patients screened at university heart failure programs in North Carolina were included in the study if they had a left ventricular ejection fraction of 40% or less during the preceding year and a New York Heart Association functional class of I through IV for at least three months, but were excluded if they were dependent on a pacemaker, had uncontrolled hypertension, had a history of myocardial infarction, or had undergone either percutaneous coronary intervention or coronary artery bypass grafting within the preceding three months. The study's primary end point was the time to death from, or hospitalization for, cardiovascular disease; a secondary end point was death or hospitalization attributable to any cause.

The mean age of the participants was 56.8 (range, 27 to 88 years), slightly less than one-third were women, and approximately one-half were ethnic or racial minorities. At baseline, nearly 90% of the patients were taking [beta]-blockers, angiotensin-converting enzyme inhibitors, or both, and 43 (21.1%) were taking antidepressants. Patients taking antidepressants scored higher on the Beck Depression Inventory (a self-reported measurement tool), were more likely to take a [beta]-blocker, and had a lower level of hemoglobin than those not taking antidepressants.

The researchers controlled for established risk factors, including left ventricular ejection fraction, age, the etiology of the heart failure, and the severity of the heart failure as assessed according to the serum level of N-terminal pro-B-type natriuretic peptide (NT-proBNP), a standard marker of heart failure that is secreted from the cardiac ventricles to promote vasodilation and diuresis. The NT-proBNP level correlated closely with the study's end points, and there was also a strong association between clinically significant symptoms of depression and worse outcomes in patients with heart failure that was independent of the heart failure's severity. The authors also noted that, after the severity of the symptoms of depression was controlled for, patients taking antidepressants had an unexpected and unexplained greater incidence of death from, or hospitalization for, cardiovascular disease.

The authors assert that although there is a documented association between heart failure, depression, and poor prognosis, it should not be deduced that there is a comparable, independent association between poor outcomes in heart failure and the use of antidepressants. Although the study demonstrated that association, it was not one of the defined end points and therefore is only conjecture. In addition, they note that the finding neither implies that the use of antidepressants is contraindicated in patients with heart failure nor suggests that the medications are not useful in that population, but only that patients with heart failure who take an antidepressant may need to be more closely monitored.-TS