Duration of dual antiplatelet therapy after myocardial infarction: Insights from a pooled database of the SMART-DATE and DAPT-STEMI trials

Background and aims: The optimal duration of dual antiplatelet therapy (DAPT) after myocardial infarction (MI) in patients treated with second-generation drug-eluting stent (DES) is unclear, therefore, we aim to evaluate the ischemic and bleeding risk according to DAPT duration using a pooled-analysis of two randomized trials. Methods: MI patients treated with durable-polymer second-generation DES from two randomized trials, SMART-DATE and DAPT-STEMI, were pooled. The primary endpoint was a composite of net adverse clinical events (NACEs) defined by all-cause mortality, any MI, stroke and BARC 3-5 bleeding, between 6 and 18 months after index percutaneous coronary intervention. Results: A total of 2016 patients were analyzed, 1014 were treated with 6-month DAPT versus 1002 patients with ≥12-month DAPT duration. The primary endpoint occurred in 2.7% vs 2.5% (HR 1.07; 95%CI 0.62–1.85, p = 0.80) of cases, in 6 vs ≥ 12-month DAPT, respectively. The composite of cardiac death, MI and stroke was similar (2% vs 1.6%, HR 1.24, 95%CI 0.65–2.4, p = 0.52). BARC 3-5 bleeding occurred more frequently in the ≥12-month DAPT (0.2% vs 0.9%, HR 0.22, 95%CI 0.05–1.02 p = 0.05, log rank p = 0.03). MI occurred more frequently in the 6-month DAPT (1.6% vs 0.6%, HR 2.66, 95%CI 1.04–6.79, p = 0.04). Stent thrombosis was similar in both arms (0.7% vs 0.5%, p = 0.26). Conclusions: Six vs ≥ 12-month DAPT, followed by aspirin alone, resulted in comparable NACEs in patients with event-free MI at six months after durable-polymer DES implantation. However, single therapy with aspirin beyond the 6 months reduced bleeding rates but was associated with a higher rate of MI compared to ≥12-month DAPT.