Adding cilostazol to a dual antiplatelet regimen of aspirin and clopidogrel appears to be as safe and effective as double-dose dual antiplatelet therapy alone for the prevention of blood clots after angioplasty.
Hyo-Soo Kim, MD, PhD, director of cardiac catheterization and coronary intervention at Seoul National University Hospital, Korea, presented data from the late-breaking HOST-ASSURE trial at the American College of Cardiology’s 61st Scientific Sessions.
Gregg W. Stone
Triple antiplatelet therapy is favored in Asia, particularly in Japan and Korea, for the treatment of high-risk patients, whereas a double-dose dual regimen is commonly used in the United States and other Western countries. However, there was no large-scale, head-to-head comparison of the two regimens with regard to clinical outcome, Kim said.
The randomized, prospective, single-blind HOST-ASSURE trial included 3,750 patients who underwent angioplasty. Researchers assigned 1,876 patients to dual therapy, using aspirin and double-dose clopidogrel (150 mg) and 1,879 patients to dual therapy plus adjunctive cilostazol. All patients received 300 mg to 600 mg clopidogrel plus 300 mg aspirin before angioplasty, with or without a loading dose of 200 mg cilostazol. In the triple therapy group, 100 mg cilostazol twice daily was added to dual therapy for 1 month after the procedure; in the dual therapy group, the maintenance regimen was 150 mg clopidogrel plus aspirin.
One month after angioplasty, the composite primary endpoint of CV-related death, nonfatal MI, stroke and major bleeding occurred in 1.4% of the double-dose dual therapy group vs. 1.2% of the triple therapy group.
“The adjunctive use of cilostazol in addition to conventional dual antiplatelet therapy was noninferior to doubling the maintenance dose of clopidogrel in this all-comer PCI population receiving exclusively drug-eluting stents, with regard to net clinical outcome at 1 month,” Kim said during the session.
Fewer MIs occurred in the triple therapy group (one vs. five). Overall, double-dose dual therapy was associated with fewer adverse events (eight total), but none of the 34 patients in the triple therapy group who experienced adverse events developed life-threatening or severe reactions.
Kim highlighted another significant finding, which was that spontaneous infarction after discharge was reported in no patients assigned triple therapy but five patients assigned double-dose dual therapy.
During a press conference, Gregg W. Stone, MD, director of cardiovascular research and education at Columbia University Medical Center/New York-Presbyterian Hospital, commented on the “striking” finding of low event rates in HOST-ASSURE.
“In the Asian population, whether [related to] genetic differences or diet, event rates are extremely low. Here [in the United States] they are three to four times higher,” he said.
The HOST-ASSURE researchers said this is the biggest clinical trial ever conducted in South Korea. Patients will continue to be followed for an additional 3 years.
The 2 x 2 factorial trial was designed to compare the two antiplatelet regimens and two types of drug-eluting stents. The stent data will be reported in the future, Kim said. – by Katie Kalvaitis
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Disclosure: Dr. Kim reports no relevant financial disclosures. Dr. Stone serves as a consultant to Atrium Medical, Eli Lilly, Medtronic and The Medicines Company.