Second-generation drug-eluting stent implantation followed by 6- versus 12-month dual antiplatelet therapy: the SECURITY randomized clinical trial

Background: The optimal duration of dual antiplatelet therapy (DAPT) following second-generation drug-eluting stent (DES) implantation is still debated.

Objectives: The aim of this study was to test the noninferiority of 6 versus 12 months of DAPT in patients undergoing percutaneous coronary intervention with second-generation DES.

Methods: The SECURITY (Second Generation Drug-Eluting Stent Implantation Followed by Six- Versus Twelve-Month Dual Antiplatelet Therapy) trial was a 1:1 randomized, multicenter, international, investigator-driven, noninferiority study conducted from July 2009 to June 2014. Patients with a stable or unstable angina diagnosis or documented silent ischemia undergoing revascularization with at least 1 second-generation DES were eligible. The primary endpoint was a composite of cardiac death, myocardial infarction (MI), stroke, definite or probable stent thrombosis, or Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding at 12 months. The main secondary endpoint was a composite of cardiac death, MI, stroke, definite or probable stent thrombosis, or BARC type 2, 3, or 5 bleeding at 12 and 24 months.

Results: Overall, 1,399 patients were enrolled in the study and randomized to receive 6 months (n = 682) versus 12 months (n = 717) DAPT. The primary composite endpoint occurred, respectively, in 4.5% versus 3.7% (risk difference 0.8%; 95% confidence interval [CI]: -2.4% to 1.7%; p = 0.469) at 12 months. The upper 95% CI limit was lower than the pre-set margin of 2%, confirming the noninferiority hypothesis (p < 0.05). Moreover, no differences were observed in the occurrence of the secondary endpoint at 12 months (5.3% vs. 4.0%, difference: 1.2%; 95% CI: -1.0 to 3.4; p = 0.273) and between 12 and 24 months (1.5% vs. 2.2%, difference: -0.7%; 95% CI: -2.1 to 0.6; p = 0.289). Finally, no differences were observed in definite or probable stent thrombosis at 12 months (0.3% vs. 0.4%; difference: -0.1%; 95% CI: -0.7 to 0.4; p = 0.694) and between 12 and 24 months of follow-up (0.1% vs. 0%; difference: 0.1%; 95% CI: -0.1 to 0.4; p = 0.305).

Conclusions: In a low-risk population, the noninferiority hypothesis of 6 vs. 12 months DAPT following second-generation DES implantation appears accepted for the incidence of cardiac death, MI, stroke, definite/probable stent thrombosis, and BARC type 3 or 5 bleeding at 12 months. (Second Generation Drug-Eluting Stent Implantation Followed by Six- Versus Twelve-Month Dual Antiplatelet Therapy; NCT00944333).