Credit: Andre E.X. Brown
WASHINGTON, DC—New research indicates that patients may only need 6 months of dual antiplatelet therapy (DAPT) after receiving a second-generation drug-eluting stent.
Results of the SECURITY trial showed that patients had similar outcomes whether they received DAPT for 6 months or a full year.
The proportion of patients who met a composite endpoint of cardiac, thrombotic, and bleeding events was low among both treatment groups at the 12- and 24-month time points.
Antonio Colombo, MD, of San Raffaele Scientific Institute in Milan, Italy, and his colleagues reported these findings at TCT 2014 and in the Journal of the American College of Cardiology.
SECURITY was a randomized, multicenter study that aimed to address the need for prolonged use of DAPT following the implantation of a second-generation drug-eluting stent for patients without high-risk acute coronary syndromes.
Patients with a diagnosis of stable or unstable angina or documented silent ischemia undergoing revascularization with at least 1 second-generation drug-eluting stent were eligible for the study. The stents used were the Endeavor Resolute (Medtronic), Xience (Abbott), Promus (Boston Scientific), Nobori (Terumo Corporation), and the Biomatrix (Biosensors Europe SA).
Of 1399 patients, 682 were randomized to 6 months of DAPT, and 717 were randomized to 12 months of treatment. They received clopidogrel at 75 mg per day for at least 3 days before the procedure or a pre-procedural loading dose of a minimum of 300 mg of clopidogrel, if they were not on chronic clopidogrel therapy.
In the post-procedure period, patients received 75 mg of clopidogrel for 6 or 12 months, according to randomization. They also received aspirin indefinitely. And once the new antiplatelet compounds prasugrel and ticagrelor hit the market, they were allowed as treatment options in a protocol amendment.
At 12 months, the incidence of the primary endpoint—the composite of cardiac death, myocardial infarction (MI), stroke, definite or probable stent thrombosis, or BARC type 3 or 5 bleeding—was 4.5% in the 6-month DAPT group and 3.7% in the 12-month DAPT group (P=0.469).
After 24 months, the 6-month and 12-month groups still showed similar incidences of cardiac death (0.9% vs 0.8%, P=0.925), MI (3.1% vs 2.6%, P=0.636), stroke (0.9% vs 0.4%, P=0.636), stent thrombosis (0.4% vs 0.4%, P=0.951), and BARC 3 or 5 bleeding (0.7% vs 1.1%, P=0.496).
Rates of the secondary endpoint—a composite of cardiac death, spontaneous MI, stroke, definite or probable stent thrombosis, or BARC type 2, 3, or 5 bleeding at 12 and 24 months—were also similar among the 6-month and 12-month treatment groups.
At 12 months, the incidence of the secondary composite endpoint was 5.3% in the 6-month group and 4.0% in the 12-month group (P=0.273). In the year that followed, both groups had lower incidences of secondary composite endpoints—1.5% and 2.2%, respectively (P=0.289).
A multivariable analysis showed that an age of 75 years or older, the type of stent used, the mean number of stents implanted, the mean stent length, and the mean stent size were all significant independent predictors of the primary endpoint.
The SECURITY trial was funded by grants from Medtronic and Terumo, makers of 2 brands of drug-eluting stents used in the study.
