People who survive 2 ischemic events (myocardial infarction or ischemic stroke) have a lower risk for a future event if treated with clopidogrel rather than aspirin, according to an article in the January 23rd rapid access issue of Stroke.

An international team identified patients with a history of two previous ischemic events within the larger database for the Clopidogrel Versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial. In the overall study, participants treated with clopidogrel had an 8.7-percent lower relative risk than patients taking aspirin. Among the 4,496 patients who had had their second ischemic event before enrollment, the clopidogrel group had an even greater advantage: a 14.9-percent lower relative risk.

The 2 composite end points (at 1 and 3 years) were ischemic stroke, myocardial infarction, or hospitalization for ischemia or mortality due to ischemic stroke, myocardial infarction, or other vascular cause.

The current study confirmed that people who have a second ischemic event have a high risk for a third, said Deepak L. Bhatt, MD, a coauthor. He added that it is also important for physicians and patients to realize that a second or third event may not be the same as the first.

“Just because a patient came in with a heart attack today doesn’t mean he or she is only at risk for a future heart attack,” Bhatt said. “The next time, it may be a stroke or other arterial problem.” The same mechanism?atherosclerosis-related ischemia?underlies myocardial infarctions, strokes, and peripheral vascular problems in the legs and elsewhere in the body.

At 1 year after their second event, 16.1 percent of the clopidogrel group and 18.5 percent of the aspirin group had had a third event (stroke or myocardial infarction) or ischemia-related hospitalization. At 3 years, 32.7 percent of those on clopidogrel and 36.6 percent of those on aspirin had another event.

At 3 years, 20.4 percent of patients in the clopidogrel group and 23.8 percent in the aspirin group had died from a subsequent event. Statistically, the findings indicate that treating 29 of these very high-risk patients with clopidogrel would prevent 1 death or nonfatal myocardial infarction or ischemic stroke over 3 years.