Patients implanted with a drug-eluting stent who have coronary artery disease may benefit from dual anti-platelet therapy for longer than the standard year, according to the landmark DAPT study of 10,000 DES patients.
The study compared DAPT treatment for 12 months with a 30-month course in preventing stent thrombosis and a composite of death, heart attack or stroke. Results were presented yesterday at the American Heart Assn.’s annual meeting and published in the New England Journal of Medicine.
Patients who took either clopidogrel (Plavix) or prasugrel (Effient) plus aspirin for 30 months showed a 71% lower risk for stent thrombosis compared with patients who took only aspiring after 12 months, according to the study, and a 29% lower risk of heart attack and stroke.
"The benefits of continuing dual anti-platelet therapy for 30 months were quite remarkable. The relative risk of a stent-related blood clot was reduced by 71%, compared with taking only aspirin after 1 year. The DAPT study was the 1st and only study that was adequately powered to detect this benefit. Furthermore, the relative risk of heart attack was reduced by 53% by preventing these stent-related events, as well as by preventing events in vessels beyond the stented lesion," principal investigator Dr. Laura Mauri of Boston’s Brigham & Women’s Hospital said in prepared remarks. "The study is a result of unprecedented collaboration amongst industry, government and academia, and valuable contributions from the investigators and patients.”
The trial excluded patients with a high risk of bleeding and showed an increase of bleeding events, but Mauri said severe bleeding was uncommon was fatal in only 0.1% of patients.
"Yes, there was an increased bleeding risk, but only 1 in 1,000 of those bleeds were fatal. So the benefit of longer therapy clearly outweighs the risk in this population. But you have to remember that the patents at highest risk of ischemic events were not randomized, as they would already have been given longer-duration treatment, and those with a high risk of bleeding were also excluded, as you wouldn’t think of continuing in this group," she told heartwire.
