SUNDAY, March 5, 2006 (HealthDay News) -- Men and women with coronary artery disease who take antidepressants appear to be at a higher risk of dying, surprising new research suggests.
There was no ready explanation for the finding, which contradicts previous studies.
"This was an unexpected finding," said study co-author James Blumenthal, a professor of medical psychology at Duke University Medical Center. "There is no obvious explanation."
But, he added, "it is improper to conclude that antidepressants caused the patients to die."
"It contradicts what we were hoping," added Dr. Nieca Goldberg, chief of women's cardiac care at Lenox Hill Hospital in New York City and a spokeswoman for the American Heart Association. "But we can't prove it one way or the other."
The research, presented Saturday at the American Psychosomatic Society meeting in Denver, showed that, even after adjusting for a variety of factors, the researchers found heart patients taking antidepressants had a 55 percent higher risk of dying than those not taking antidepressants. There was no statistical significant difference between those taking selective serotonin reuptake inhibitors (SSRIs) and those taking other types of antidepressants.
Previous research had found that heart patients with depression had a heightened risk of dying, possibly because depression increases the propensity of blood platelets to stick together. As a result, many physicians treat such heart patients with antidepressants to offset that risk.
One recent study found that antidepressants almost halved the risk of death or a second heart attack in people who had had a first heart attack.
That research notwithstanding, there have been few studies done on the effects of antidepressants in people with heart disease.
For this study, the Duke researchers analyzed information on 921 patients receiving a cardiac angiography to determine how blocked their coronary arteries were. Almost 20 percent of the participants were taking an antidepressant and, of those, 66 percent were taking an SSRI.
Those who were not taking antidepressants had a score of 7 on a widely used depression scale, while those on antidepressants had an average score of 11. A score of 10 or higher means the person is considered depressed, the study noted.
Over the course of three years, 21.4 percent of the patients taking antidepressants died, vs. 12.5 percent in the group not taking antidepressants.
The study does, however, have limitations, the main one being that it was not randomized.
There was also no indication whether the depressed patients had benefited at all from taking antidepressants, Goldberg said.
Duke researchers are already enrolling patients in a randomized trial to see if exercise and SSRIs affect such biomarkers of coronary artery disease as heart rate variability and platelet aggregation, or "stickiness."
"This is interesting and different from what we had thought, because we generally consider these medications to be safe," Goldberg said. "It doesn't mean we should not treat depression, but we need to understand why this happened as opposed to just making the observation that it happened."
More information
For more on depression and heart disease, visit the American Academy of Family Physicians.
