Dual antiplatelet therapy beyond 12 months versus for 12 months after drug-eluting stents for acute myocardial infarction

Abstract

BackgroundThe optimal duration of dual antiplatelet therapy (DAPT) after acute coronary syndrome remains uncertain. This study investigated the benefit of DAPT beyond 12 months after drug-eluting stents (DES) for acute myocardial infarction (MI). MethodsFrom Korea Acute Myocardial Infarction Registry-National Institute of Health database, 6199 patients treated with DAPT for 12 months after DES (second-generation DES 98%) without ischemic or bleeding events were analyzed. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), a composite of death from any cause, MI, or ischemic stroke during the period from 12 to 24 months. ResultsAfter adjustment using inverse probability of treatment weighting, patients who received DAPT beyond 12 months (n=4795), compared to patients treated with 12-month DAPT (n=1404), had a similar incidence of MACCE (1.3% vs. 1.0%, HR: 1.32, 95% CI: 0.71–2.45, p=0.378). The 2 groups did not differ significantly in the rates of death (0.1% vs. 0.1%), MI (0.8% vs.0.6%), stent thrombosis (0.1% vs. 0.2%), ischemic stroke (0.4% vs. 0.2%), and major bleeding (0.1% vs. 0.1%). The rate of net adverse clinical events was 1.4% with DAPT beyond 12 months and 1.1% with 12-month DAPT (p=0.466). ConclusionsDAPT beyond 12 months, as compared with 12-month DAPT, in real-world patients with acute MI treated predominantly with second-generation DES did not reduce the risk of MACCE. The rates of major bleeding and net adverse clinical events did not differ significantly between the 2 treatments.