Short-Term Versus Long-Term Dual Antiplatelet Therapy After Drug-Eluting Stent Implantation in Elderly Patients: A Meta-Analysis of Individual Participant Data From 6 Randomized Trials

Objectives: This study sought to evaluate the optimal duration of dual antiplatelet therapy (DAPT) after the implantation of a drug-eluting stent (DES) in elderly patients. Background: Qualified studies to evaluate the optimal duration of DAPT in elderly patients have been very limited. Methods: Using 6 randomized trials that compared short-term (≤6 months) and long-term (12 months) DAPT, individual participant data meta-analysis was performed in elderly patients (≥65 years of age). The primary study outcome was the 12-month risk of a composite of myocardial infarction, definite or probable stent thrombosis, or stroke. The major secondary outcome was the 12-month risk of major bleeding. Results: The primary outcome risk did not significantly differ between patients receiving short-term and long-term DAPT (hazard ratio [HR]: 1.12; 95% confidence interval [CI]: 0.88 to 1.43; p = 0.3581) in the overall group of study participants. In subgroup analysis, a significant interaction between age and DAPT duration was observed for primary outcome risk (p for interaction = 0.0384). In the subset of younger patients (<65 years of age, n = 6,152), short-term DAPT was associated with higher risk of primary outcome (HR: 1.67; 95% CI: 1.14 to 2.44; p = 0.0082). In elderly patients (n = 5,319), however, the risk of primary outcome did not significantly differ between patients receiving short-term and long-term DAPT (HR: 0.84; 95% CI: 0.60 to 1.16; p = 0.2856). Short-term DAPT was associated with a significant reduction in major bleeding compared with long-term DAPT (HR: 0.50; 95% CI: 0.30 to 0.84; p = 0.0081) in the overall group, and particularly in elderly patients (HR: 0.46; 95% CI: 0.24-0.88; p = 0.0196). Conclusions: Short-term DAPT after new-generation DES implantation may be more beneficial in elderly patients than in younger patients.