Antidepressants Lower Heart Attack Risk

Selective Serotonin Reuptake Inhibitors Lessen Chances of Heart Attacks in Smokers

(Philadelphia, PA) - Drugs designed to fight depression may also prevent heart attacks, according to researchers at the University of Pennsylvania Medical Center. In a large study of smokers, the researchers associated a class of antidepressants, called selective serotonin reuptake inhibitors (SSRIs), with a lower heart attack risk. Their findings are published in the latest issue of Circulation: Journal of the American Heart Association.

"We found a 65 percent reduction in risk of a heart attack among SSRI users compared to nonusers," said Stephen Kimmel, MD, associate professor of medicine in the Penn Department of Biostatistics and Epidemiology and the Cardiovascular Division of the Penn Department of Medicine. "How it works is still unknown, but we have reason to believe that, like aspirin, SSRIs act to thin the blood and prevent clotting."

In the study, Kimmel and his colleagues compared people in an eight-county region around the Philadelphia metropolitan area who were hospitalized for a first heart attack (653 people) with a randomly selected group of people who had no history of a prior heart attack (2,990 people). All patients in both groups were smokers.

Of the 143 SSRI users identified, 87 percent said they were taking the drugs for depression; 3.5 percent for anxiety and 9.1 percent for unknown or other indication. Patients were studied over a 28-month period and were between the ages of 30 and 65 years old. The SSRIs identified in this study included fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil) and sertraline (Zoloft).

"We actually collected this data for a study to test the value of nicotine patches in preventing heart attacks, since smoking is a high risk factor," said Kimmel. "In doing so we also collected detailed information about the prescription drug use of participants in the study."
The data Kimmel and his colleagues received allow them to also compare the risk of heart attacks in people who used antidepressants.

In addition to smoking, studies have also suggested that depression may be a risk factor for heart disease and is linked to a higher probability of death after a heart attack. Earlier studies had suggested the association between antidepressants and lower heart attack risk. With the ready made pool of information, this study became the largest of its kind to examine whether SSRIs prescribed for depression lowered the risk of a first non-fatal heart attack.

The researchers were not, however, able to directly determine from the data how SSRIs may protect from heart attack. According to Kimmel, the study could not distinguish between whether the beneficial effects of treating depression reduced the risk of heart attack or if it was the SSRIs' pharmacological effects. As devised, the study did not involve the use of validated depression scales, which are used to assess the severity of depression - and therefore were unable to reach a definitive conclusion.

Tentatively, Kimmel and his colleagues theorize that the drugs might protect the heart the same way aspirin does, by preventing platelets, the parts of the blood that form clots, from clumping together. The majority of heart attacks are caused by blood clots.

The researchers believe that a randomized controlled trial study of significant size would be necessary to make a definitive link between SSRIs and preventing heart attacks. They also suggest that other forms of antidepressant medications aside from SSRIs be taken into account to determine if they may have a similar effect.

"However provocative, these are just preliminary findings," said Kimmel. "We did not start out looking at this problem, exactly, but it does provide a springboard for further research - both statistically, such as ours, and in the laboratory."

Penn researchers, William H. Sauer, MD, and Jesse A. Berlin ScD, were co-investigators in this project.
Funding for this study was provided by Aventis Pharmaceuticals, Novartis Consumer Health, and McNeil Consumer Products Co.

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Editor's Note: Neither Dr. Sauer, Dr. Berlin, nor Dr. Kimmel have any financial stake in Aventis Pharmaceuticals, Novartis Consumer Health, or McNeil Consumer Products Co.

The University of Pennsylvania Health System is distinguished not only by its historical significance - first hospital (1751), first medical school (1765), first university teaching hospital (1874), first fully integrated academic health system (1993) - but by its position as a major player on the world stage of medicine in the 21st century. Committed to a three-part mission of education, research, and clinical excellence, UPHS has excelled in all three areas. Penn ranked second among all American medical schools that received funds from the National Institutes of Health, perhaps the single most important barometer of research strength.