A team of researchers from Washington University School of Medicine in St. Louis, the Mayo Clinic in Rochester, Minn., the Harvard School of Public Health and several other clinical centers around the United States has found that treating depression and social isolation in recent heart attack patients does not reduce the risk of death or second heart attack.
Results from the Enhancing Recovery in Coronary Heart Disease Patients Study (ENRICHD) are published in the June 18 issue of the Journal of the American Medical Association.
“The findings were disappointing,” says Robert M. Carney, Ph.D., a lead investigator and professor of psychiatry at Washington University School of Medicine in St. Louis. “However, I think we learned a number of things, and perhaps we can design more effective treatments for depression and social isolation that may finally lower the risks for these patients.”
Social isolation and depression are important risk factors for heart attack and death. About 25 percent of heart attack patients have one of these conditions, contributing to a three- to four-fold increase in their risk of death. The ENRICHD study hoped to change those odds by offering treatment to heart attack patients with depression or low social support.
Researchers at eight clinical centers studied 2,481 heart attack patients. They were enrolled in the study within 28 days of their heart attacks. Some 39 percent of patients were depressed. Another 26 percent had low perceived social support, and 34 percent had both.
Individuals in the study were randomly assigned to one of two groups. One group did not receive any special treatment for their depression, while the other group got cognitive behavior therapy for six months, detailed assessments and assistance with social support and, in some cases, antidepressant medication.
Patients were followed for 29 months. In the group that received standard medical care without treatment for depression, 75.9 percent survived and did not suffer a second heart attack. In the group that received additional treatment for depression, 75.8 percent still were alive with no second heart attack after 29 months.
“The rates were virtually identical,” says Allan S. Jaffe, M.D., a study co-chair and professor of medicine at the Mayo Clinic in Rochester. “Looking at the data retrospectively, it did appear that the risk of death or second heart attack was lower among patients in either group who were taking antidepressant drugs. This finding is intriguing but far from definitive because this study was not set up to test the effects of antidepressant drugs, so the data to be sure about this effect was not available.”
The study did find that patients who received treatment for their depression and social isolation experienced an improved quality of life. After six months, depressed patients receiving treatment experienced a 57 percent reduction in depression, compared to a 47 percent reduction in the usual care group. Patients with low social support experienced a 27 percent improvement with treatment, compared to an 18 percent improvement in the group who received standard medical care.
“The good news is that their quality of life improved,” Carney says. “There’s clearly an interaction between heart disease and depression, and this study demonstrates that depression can be treated in this population of patients, but we had hoped to have a significant impact on survival, too.”
Only about one in four depressed heart attack patients ever receives treatment for depression. Assistance and treatment also are rare for patients with low perceived social support. The investigators had hoped to demonstrate that treating these risk factors would improve survival and lower the risk of a second heart attack, and they say in spite of the results, their hypothesis may be a good one. It is possible that the treatment was where the study fell short.
“We need to determine the amount of improvement in depression and social support that’s needed to affect survival,” says Lisa Berkman, Ph.D., study chair and epidemiologist at the Harvard School of Public Health in Boston. “It’s possible that if we could improve the intervention and provide more effective treatments for depression and social isolation, we might have a greater impact on survival.”
Writing Committee for the ENRICHD Investigators. Effects of treating depression and low perceived social support on clinical events after myocardial infarction: the enhancing recovery in coronary heart disease patients (ENRICHD) randomized trial. Journal of the American Medical Association, vol. 289:23, pp. 3106-3116, June 18, 2003, with accompanying editorial on pp. 3171-3173.
This research was supported by contracts from the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. Pfizer Inc. provided setraline (Zoloft) for the study.
The full-time and volunteer faculty of Washington University School of Medicine are the physicians and surgeons of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked second in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.