The results of CHARISMA (Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance) trial involving 15,603 patients from 32 countries, which was published in the New England Journal of Medicine, was presented at the recent annual convention of the Philippine Heart Association.
Results of the study were presented to Filipino cardiologists by noted heart specialist Dr. John Amerena, associate professor of medicine at the University of Melbourne, Australia.
In patients with cardiovascular risk factors only, the addition of clopidogrel to low-dose aspirin did not significantly reduce the rate of heart attack, stroke or death compared to the combination of aspirin and placebo (sugar pill).
The researchers concluded that dual antiplatelet therapy should not be used in patients without a history of established vascular disease.
"Dual antiplatelet therapy is important and effective, but it’s not for everyone," said Dr. Donald Easton, of the Department of Neurology, Brown University, and one of the CHARISMA investigators.
In the study, all the patients, with an average age of 64, received aspirin, the standard medication, and were randomly divided to receive clopidogrel or placebo.
More than one-third of the patients had documented cardiovascular disease, about 20 percent had multiple risk factors only, and the remaining patients had neither. They were treated and observed for 28 months.
The leading organizations of cardiologists in the United States and Europe reiterated the benefits of clopidogrel, a once-daily medicine that helps prevent blood clotting, in light of the CHARISMA results.
Clopidogrel’s efficacy has been demonstrated in a number of studies. Amerena said, "A study called CAPRIE showed that clopidogrel was more superior than aspirin in reducing risk of cardiovascular events in patients with recent heart attack, stroke, or established peripheral arterial disease."
"It is important to remember that previous trials have documented the benefits of combined treatment with clopidogrel and aspirin for patients who had heart attack or unstable angina, and those who have had coronary angioplasty with stent implant," said Dr. Ralph Sacco, a spokesman of the American Heart Association (AHA).
The CURE study reported that a combination of clopidogrel and aspirin was more effective than aspirin alone in reducing the risk of a heart attack or stroke in patients with acute coronary syndrome (ACS).
The European Society of Cardiology, in a recent statement, reminded physicians and patients that dual antiplatelet therapy, which includes clopidogrel, is "an essential, approved and recommended therapy" for patients who had ACS, including unstable angina, heart bypass and heart attack.
Clopidogrel is a prescription medicine developed by Sanofi-aventis, a research-based pharmaceutical company, which is the world’s third largest and biggest in Europe.