Did Antidepressants Reduce Heart Attack Risk?

A recent study found that patients suffering from depression who have experienced a heart attack had a reduced risk of death and recurrent heart attack while taking antidepressants, specifically SSRIs. The study was published in the July 2005 issue of the Archives of General Psychiatry.

Major depression was found in approximately 20 percent of patients with a recent myocardial infarction, with a similar prevalence was found for minor depression. Depression is a risk factor for recurrent non-fatal heart attack and cardiac death in patients who experience an acute heart attack, independent of the severity of heart disease. Selective serotonin reuptake inhibitors (SSRIs) are a class of antidepressants that act within the brain to increase the amount of the neurotransmitter serotonin. SSRIs have been the focus of much controversy for several years.

C. Barr Taylor, M.D., from Stanford Medical Center (Stanford, CA), and his colleagues conducted a secondary analysis of data from the previously conducted Enhancing Recovery in Coronary Heart Disease (ENRICHD) clinical trial to determine the effects of antidepressants on post-heart attack patients. The ENRICHD trial randomized 2,481 depressed and/or socially isolated patients from October 1996 through October 1999. The analysis in this report is based on close to two thousand patients (985 men and 849 women) who suffered from depression. Of these, 446 patients took antidepressants during the study, 301 of who were prescribed SSRIs while the rest were prescribed other types of antidepressants.

During an average follow-up of 29 months, 457 fatal and non-fatal cardiovascular events occurred. Twenty-six percent of the patients who did not receive antidepressants died or had a recurrent attack, compared to 21.5 percent of the patients who did take antidepressants. After adjusting for baseline depression and cardiac risk, SSRI use was associated with approximately 43 percent lower risk of death or recurrent non-fatal infarctions, and 43 percent lower risk of death from all causes, compared with patients not receiving SSRIs.

Despite the ostensible findings of this study, some have called the study and its methodology into question. The flaw in the study, according to Dr. Alexander H. Glassman, a professor of psychiatry at Columbia University, is that it was not originally designed to examine the effects of antidepressant treatment. Instead, nearly 2,500 patients were divided into two groups, one that received psychotherapy and one that did not. The analysis looked at the 28 percent of patients in the therapy group and the 20 percent of those in the nontherapy group who were given SSRIs because of the severity of their depression. Glassman suggests that verification of these results could come only from a large-scale study involving perhaps thousands of people diagnosed with depression after a heart attack.