The association between depression and death was only seen among patients with heart failure due to coronary heart disease, or ischemic cardiomyopathy, and not in patients with dilated cardiomyopathy, according to lead author Stephan Zipfel, M.D., despite the fact that patients with both types of cardiac condition have high rates of depression, anxiety, and physical dysfunction.

The level of depression measured before surgery was the significant predictor of post-operative survival in patients with ischemic disease. Anxiety levels did not predict poorer survival.

The German study included 103 patients who received a heart transplant (40 for ischemic cardiomyopathy and 63 for dilated cardiomyopathy). Initial interviews to assess depression, anxiety, and physical complaints were conducted after patients were placed on the waiting list for new hearts.

Of the 103 people, 39 subjects were found to have high levels of depressive symptoms, whereas 64 had few symptoms of depression.

"Symptoms of depression and anxiety are frequently encountered in patients awaiting a heart transplantation, with prevalence rates for major depression of 23.7 percent and a further significant increase in depressive symptoms during the waiting period," says Zipfel.

"Both cardiomyopathy subgroups showed significantly increased levels of psychological distress compared with health controls," but the ischemic patients showed more depression and anxiety than the dilated patients did, he says.

The researchers comment that previous study findings suggest that depression can affect heart transplant patients' compliance with immune-suppression drug regimens. Depressed patients may also fail to follow other risk-reduction strategies recommended by their doctors.

"The purpose of any pretransplant assessment should be the early identification of patients experiencing increased psychosocial distress and who thus may be at risk for a poor psychosocial and somatic outcome," the authors say.