Optimal duration of dual antiplatelet therapy after second-generation drug-eluting stent implantation in patients with diabetes: The SECURITY (Second-Generation Drug-Eluting Stent Implantation Followed by Six- Versus Twelve-Month Dual Antiplatelet Therapy)-diabetes substudy

Background/Objectives The randomized SECURITY (Second-Generation Drug-Eluting Stent Implantation Followed by Six- Versus Twelve-Month Dual Antiplatelet Therapy) trial showed the non-inferiority of 6 vs. 12-month DAPT after percutaneous coronary intervention (PCI) with second-generation DES in a low-risk population. Nevertheless, diabetes mellitus (DM) remained a major predictor of adverse cardiovascular events. We aimed to assess the interaction between DAPT duration and outcome in DM patients. Methods All diabetic patients included in the SECURITY trial treated by second-generation DES PCI were analyzed. The primary endpoint was a composite of cardiac death, myocardial infarction (MI), stroke, definite or probable stent thrombosis (ST), 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 ST, or BARC type 2, 3, or 5 bleeding at 24 months. Results Four hundred-twenty nine DM patients received either 6 (n = 206) or 12 (n = 223) months of DAPT. The primary endpoint occurred in 3.9% and 5.4% of patients in the 6 and 12-month DAPT group, respectively (log-rank test p = 0.83). Similarly, no statistically significant difference in the secondary endpoint was observed between the two study groups (5.4% vs. 7.6%, p = 0.620). Stent thrombosis rate was low irrespective of DAPT duration at both 12 (0.5% vs. 0.4%; p = 0.804) and between 12 and 24 months of follow-up (0.5% vs. 0%, p = 0.291). At multivariable analysis, female gender (HR: 3.42; 95% CI 1.32-8.85; p = 0.011 and HR 2.28; 95% CI 1.09-4.75; p = 0.027) and insulin-treated diabetes mellitus (HR: 2.62; 95% CI 1.15-6.75; p = 0.004 and HR: 2.23; 95% CI 1.09-6.33; p = 0.003) were independent predictors of both primary and secondary endpoint. Conclusions In diabetic patients treated by second-generation DES PCI, we failed to find any additional benefit of prolonging DAPT beyond 6 months, regardless of insulin-requiring status.