March 12, 2006
Data from a long-term study solidifies aspirin's role as the preeminent antiplatelet therapy in the prevention of heart attack and stroke, according to an article in an advance issue of the New England Journal of Medicine.
The study results were presented today at the 55th Annual Scientific Session of the American College of Cardiology in Atlanta. They reaffirm the primacy of aspirin among antiplatelet agents and add to the robust body of evidence supporting aspirin's role in cardioprevention.
Overall, the study showed that there was no significant benefit to adding the anti-platelet aggregator clopidogrel -- known commercially as Plavix -- to aspirin therapy in a wide range of patients.
Furthermore, since patients who took clopidogrel had an increased risk of bleeding, the long-term use of combination antiplatelet therapy may not be warranted in most patients, the authors said.
The study, formally known as the Clopidogrel for High Atherothrombotic Risk and Ischaemic Stabilization, Management, and Avoidance (CHARISMA), "reaffirms the favorable benefit-to-risk and benefit-to-cost ratio of aspirin in the treatment and prevention of heart attack and stroke," said Charles H. Hennekens, M.D., Professor at Florida Atlantic University and the University of Miami School of Medicine, who pioneered many early landmark trials of aspirin.
"Antiplatelet therapy with aspirin ... has earned its rightful place as a cornerstone of treatment for reducing cardiovascular events in patients with established vascular disease," an accompanying editorial said.
"These findings are particularly welcome news worldwide, with cardiovascular disease rising from the fifth to the leading cause of death. Aspirin is both effective and affordable for the millions of people worldwide who could benefit. Wider utilization is needed in both developing and developed countries, like the US," Hennekens concluded.
The CHARISMA trial is an international, multicenter, double-blinded, placebo-controlled study involving 15,603 patients aged 45 years or older who were at high risk of heart attack, stroke or death from cardiovascular disease.
The study was designed to assess whether adding clopidogrel (75 mg/day) to aspirin therapy (75-162 mg/day) provided any benefit over aspirin monotherapy in preventing the occurrence of those events.
The study's efficacy results showed that the addition of clopidogrel to aspirin therapy did not result in a significant lowering (p =0.22) of risk of the primary endpoint, the combined risk of heart attack, stroke or cardiovascular death (6.8 percent in the clopidogrel plus aspirin group and 7.3 in the aspirin-only group -- a difference that was not statistically significant).
Additionally, the rate of moderate-to-severe bleeding was increased in the patients taking clopidogrel with aspirin compared to the rate in those taking aspirin alone.
In general, aspirin is recognized for its benefits as first-line therapy across a wide cardiovascular risk continuum because of its proven efficacy, safety and cost-effectiveness; benefits that have been demonstrated in more than 200 trials involving over 200,000 patients, the authors noted.
