Patients who develop coronary artery disease and are subsequently diagnosed with depression have an increased risk of heart failure, even if they are taking antidepressant medication, according to findings from the Intermountain Heart Collaborative Study.

Although depression in heart failure is a recognized risk factor for adverse cardiovascular outcomes, Dr. Heidi T. May and co-authors state in the Journal of the American College of Cardiology, their study is the first to assess whether depression following a diagnosis of coronary artery disease is associated with the onset of heart failure.

Included in the study were 13,708 patients (average age of 64 years) who did not have a diagnosis of depression, heart failure or history of antidepressant use when they were first diagnosed with coronary artery disease. Depression was later diagnosed in 1377 subjects and heart failure in 674.

The incidence of heart failure was 3.6 per 100 among coronary artery disease patients without a diagnosis of depression and 16.4 per 100 for those with the dual diagnosis, the authors report.

The results of further analyses revealed that depression without or with treatment with an antidepressant drug was still associated with heart failure.

“Antidepressant therapy may not be able to alter the physiological and/or behavioral risks associated with depression and heart failure, despite a potential improvement in depressive symptoms,” note May of the Intermountain Medical Center in Murray, Utah, and her associates.

On the other hand, antidepressant treatment in the absence of depression was not associated with heart failure. Therefore, they suggest that “when designing future epidemiological studies, the use of antidepressant therapy as a surrogate for depression should be used with caution.”

The research team points out that depression and heart failure are two of the most burdensome diseases in terms of health care utilization and limitations in daily functioning.

Although their findings require further investigation, they believe that future interventions could have a significant public health impact by reducing illness, death rates, and health care expenditures.

SOURCE: Journal of the American College of Cardiology, April 21, 2009.