Depression and perceived low social support are associated with increased morbidity and mortality in patients with coronary heart disease (CHD), and depression is an independent risk factor for mortality after myocardial infarction (MI). One trial has shown that depression in post-MI patients can be treated successfully, but no trial has shown that treatment improves survival in patients with CHD. This randomized, controlled, multicenter trial was conducted by the committee for the Enhancing Recovery in Coronary Heart Disease Patients trial to determine whether treating depression and increasing social support reduce the risk of recurrent nonfatal MI and death.
Patients with acute MI who were found to be depressed or to have perceived low social support according to a semistructured interview and a social support instrument were eligible for the study. Participants received baseline electrocardiography; a medical history and physical examination were obtained; and several depression scales were administered. Patients were randomized to an intervention group and a usual-care group. The intervention group received cognitive behavior therapy. Patients with perceived low social support also received a social support assessment, with counseling sessions focusing on behavior and social skill deficits, cognitive factors contributing to unsatisfactory levels of support, and social outreach guidance. Patients who continued to be depressed according to specific criteria were referred after five weeks for consideration of pharmacotherapy.
Patients were given sertraline or an alternative medication (a different selective serotonin reuptake inhibitor or nortriptyline), depending on tolerability and response to the medication. Behavior therapy continued for up to six months, with group therapy permitted to continue an additional 12 weeks and pharmacotherapy an additional 12 months or more as needed. Follow-up visits occurred six months after randomization and annually thereafter, with primary end points being recurrent MI or death from any cause. Secondary end points included revascularization and cardiovascular hospitalizations.
Of the 2,481 randomized patients, 1,243 were assigned to usual care and 1,238 to intervention. All patients were followed for at least 18 months. Four-year survival curves showed no significant difference between treatments in the primary or secondary end points. The intervention group showed significant but modest improvements in depression and social support compared with the control group. At six months, the mean Beck Depression Inventory score was 9.1 in the intervention group versus 12.2 in the usual-care group (P < .001), with comparable differences in the Hamilton Rating Scale for Depression score. Of 1,238 patients, 1,145 (92 percent) received the intervention as assigned. Patients attended a median of 11 sessions.
Antidepressant use, which was greater in the intervention group than in the usual-care group throughout the duration of the trial, was associated with a lower risk of nonfatal MI or death. According to further analysis, the high rate of antidepressant use in both groups did not influence the finding that behavior therapy lacked benefit.
The intervention group showed significant improvements in social support and depression without showing any impact on cardiac morbidity and mortality end points. The investigators found that antidepressant use was associated with lower infarction and mortality risk, perhaps because of mechanisms independent of the medications' effect on depression. There may be many reasons for the null results of this trial, including timing and duration of the intervention, lack of motivation in the patients, the inability to detect an effect in a group already receiving state-of-the-art cardiac care, and possible lack of resources to facilitate participation in behavior therapy.
Previous studies have demonstrated that depression and perceived low social support are independent risk factors for cardiac events, but reversing these conditions may not have sufficient, or any, impact on the underlying pathophysiology. The authors recommend identifying and treating post-MI depression, however, because even without improved cardiac outcomes, quality of life improves.