November 17, 2014 — Researchers have found that patients implanted with a coronary stent are more likely to die or bleed if they use Plavix and aspirin for 30 months, but they are 29% less likely to have a heart attack or stroke, and 71% less likely to have a blood clot.
Those conclusions were published in the New England Journal of Medicine and based on data from 10,000 patients enrolled in the Dual Anti-Platelet Therapy (DAPT) study.
All of the patients were implanted with a coronary stent, which is a tube made of metal mesh that is designed to prop open narrow arteries and maintain circulation of blood to the heart.
Most stent patients are implanted with a drug-eluting stent, which is designed to slowly release a medicine that helps keep the artery open. Patients with drug-eluting stents must take a blood-thinning drug like Plavix (clopidogrel) or Effient (prasugrel) for 6-12 months.
No one knows the safety risks beyond 12 months, so researchers decided to compare outcomes at 12 months and 30 months.
An unexpected outcome was that 2% of stent patients died after taking a blood-thinning drug for 30 months, compared to 1.5% of patients on a placebo. Not surprisingly, blood-thinning drugs significantly increased a patient’s risk of bleeding. About one in 1,000 of those bleeds were deadly.
The FDA is reviewing results of the study and has not changed recommendations or come to any conclusions. According to the FDA Safety Communication:
“The higher rate of death was largely explained by an increase in deaths from non-cardiovascular causes, primarily cancer and trauma deaths. The increased risk of death with longer treatment was seen in the patients given clopidogrel, but not those given prasugrel.”