NEW YORK (Reuters Health) – Despite leading guidelines that suggest clopidogrel be given for 12 months after placement of a drug-eluting stent (DES), patients treated for 6 months may fare just as well in the long term as patients who use the drug for a whole year, according to results of a new study.

“The benefit of clopidogrel use beyond 6 months after DES implantation remains uncertain,” Dr. Tae-Jin Youn, from Seoul National University, Korea and co-researchers note, “and hence the decision to use long-term dual-antiplatelet therapy (aspirin plus clopidogrel) should be based on the risk factors of each patient.”

Dr. Youn’s group notes that evidence for the 2005 guidelines – issued jointly by the American College of Cardiology, American Heart Association, and Society for Cardiovascular Angiography and Interventions — is based only on a handful of observational reports.

To further investigate, Dr. Youn and colleagues compared two-year outcomes in 575 patients who continued clopidogrel beyond 6 months and 163 who did not. All of the patients had been event-free at 6 months.

The majority of subjects were men (70.1%), the average age was 63 years, and about 26% were smokers.

During a median follow-up period of 2.02 years, 7 deaths, 3 myocardial infarctions, and 2 episodes of stent thrombosis occurred.

The composite endpoint of death, myocardial infarction, and stent thrombosis occurred at nearly the same rate in both patient groups, roughly 2.9%.

Moreover, on analysis that included time-dependent covariates, the rates of reaching this endpoint during periods with or without clopidogrel use were comparable, although broad effect estimates were noted, the authors state.

“This cohort of Korean patients failed to show an absolute benefit of long-term clopidogrel therapy after DES implantation,” Dr. Youn’s team concludes. Still, they note that continuing clopidogrel beyond 6 months may be a reasonable approach in high-risk patients.

Reference:
Am J Cardiol 2009;104:1668-1673.