Benefits and Risks of Extended Dual Antiplatelet Therapy After Everolimus-Eluting Stents

The purpose of this study was to characterize outcomes for everolimus-eluting stent (EES)-treated subjects according to treatment with continued thienopyridine plus aspirin versus aspirin alone 12 to 30 months after stenting.

In the DAPT (Dual Antiplatelet Therapy) study, continued thienopyridine plus aspirin beyond 1 year after coronary stenting reduced ischemic events. Given low rates of stent thrombosis and myocardial infarction (MI) for current drug-eluting stents, we examined outcomes among EES-treated subjects in the DAPT study.

The DAPT study enrolled 25,682 subjects (11,308 EES-treated) after coronary stenting. Following 12 months of treatment with thienopyridine and aspirin, eligible subjects continued treatment with aspirin and 9,961 (4,703 with EES) were randomized to 18 months of continued thienopyridine or placebo. Stent type was not randomized, and the EES subset analysis was post hoc.

Among EES-treated patients, continued thienopyridine reduced stent thrombosis (0.3% vs. 0.7%, hazard ratio [HR]: 0.38, 95% confidence interval [CI]: 0.15 to 0.97; p = 0.04) and MI (2.1% vs. 3.2%, HR: 0.63, 95% CI: 0.44 to 0.91; p = 0.01) versus placebo but did not reduce a composite of death, MI, and stroke (4.3% vs. 4.5%, HR: 0.89, 95% CI: 0.67 to 1.18; p = 0.42), and increased moderate/severe bleeding (2.5% vs. 1.3%, HR: 1.79, 95% CI: 1.15 to 2.80; p = 0.01), and death (2.2% vs. 1.1%, HR: 1.80, 95% CI: 1.11 to 2.92; p = 0.02). Death due to cancer and not related to bleeding was increased (0.64% vs. 0.17%; p = 0.01).

In EES-treated subjects, significant reductions in stent thrombosis and MI and an increase in bleeding were observed with continued thienopyridine beyond 1 year compared with aspirin alone. (The Dual Antiplatelet Therapy Study [DAPT Study]); NCT00977938).