September 19, 2014 — A new study investigating different durations of triple therapy for anticoagulation after drug-eluting stent (DES) implantation demonstrated that six weeks of drug therapy was not superior to six months of therapy with regard to net clinical outcomes. ISAR-TRIPLE is the largest randomized trial to date investigating triple therapy after stenting and the first trial evaluating the duration of triple therapy. Findings were reported earlier this week at the 2014 Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium.
Patients with atrial fibrillation, pulmonary embolism, deep vein thrombosis or mechanical valves have an indication for oral anticoagulation (OAC). A sizeable number of these patients undergo coronary stenting and require dual antiplatelet therapy (DAPT) in addition to OAC. However, such triple therapy confers an elevated bleeding risk. Shortening the duration of DAPT may reduce the excess bleeding risk; however it may also have a negative impact on the risk of thrombotic complications.
ISAR-TRIPLE is the first trial to examine the restriction of DAPT after DES implantation in the setting of concomitant aspirin and OAC with vitamin K antagonists. The prospective, open-label trial randomized 614 patients in a 1:1 fashion to either six weeks or six months of clopidogrel therapy, in addition to aspirin plus an oral anticoagulant. The primary endpoint was a composite of death, myocardial infarction, definite stent thrombosis, stroke or TIMI major bleeding at nine months. The secondary endpoints included the composite ischemic endpoint as well as bleeding complications.
After nine months, the primary endpoint occurred in 9.8 percent of patients in the six-week group and 8.8 percent of patients in the six-month group (p=0.63.) The composite of cardiac death, myocardial infarction, stent thrombosis or ischemic stroke occurred at a similar rate in both the six-week and six-month groups (4 percent vs. 4.3 percent, respectively; p=0.87). A total of 5.3 percent of patients in the six-week group experienced major bleeding, compared to 4.0 percent in the six-month group (p=0.44).
“The shortening of triple therapy neither reduced the incidence of TIMI major bleeding nor increased the incidence of the composite of ischemic events,” said lead investigator Nikolaus Sarafoff, M.D., from Deutsches Herzzentrum and Klinikum der Universität, both in Munich, Germany. "These results suggest that physicians should weigh the trade-off between ischemic and bleeding risk when choosing the shorter or longer duration of triple therapy."
The ISAR-TRIPLE trial was funded by Deutsches Herzzentrum München. Sarafoff reported fees for lectures or traveling from Lilly/Daiichi Sankyo, Boehringer Ingelheim, Bayer Healthcare, Boston Scientific, Biotronik and Medtronic.
For more information: www.crf.org, www.tctconference.com