Early Discontinuation of Aspirin after PCI in Low-Risk Acute Myocardial Infarction

Background An appropriate duration of dual antiplatelet therapy after percutaneous coronary intervention for acute myocardial infarction that has been treated with guideline-recommended complete revascularization and a contemporary drug-eluting stent remains unclear.Methods We conducted a multicenter, open-label, randomized trial at 40 European sites. Adults with acute myocardial infarction who had undergone successful complete revascularization within 7 days after the infarction and had subsequently completed 1 month of dual antiplatelet therapy with no ischemic or major bleeding events were randomly assigned to transition to a P2Y12 inhibitor as monotherapy or to continue dual antiplatelet therapy for an additional 11 months. The primary outcome was a composite of death from any cause, myocardial infarction, stent thrombosis, stroke, or major bleeding (defined by the Bleeding Academic Research Consortium [BARC] as a bleeding event of type 3 or 5) at 11 months after randomization (tested for noninferiority with a margin of 1.25 percentage points). The main secondary outcome was BARC type 2, 3, or 5 bleeding (clinically relevant bleeding) at 11 months after randomization (tested for superiority).Results Among the 2246 enrolled patients, 1942 underwent randomization: 961 to receive P2Y12-inhibitor monotherapy and 981 to continue dual antiplatelet therapy. A primary-outcome event occurred in 20 patients (2.1%) in the P2Y12-inhibitor monotherapy group and in 21 patients (2.2%) in the dual antiplatelet therapy group (difference, -0.09 percentage points; 95% confidence interval [CI], -1.39 to 1.20; P=0.02 for noninferiority). BARC type 2, 3, or 5 bleeding occurred in 2.6% of the patients in the P2Y12-inhibitor monotherapy group and in 5.6% of those in the dual antiplatelet therapy group (hazard ratio, 0.46; 95% CI, 0.29 to 0.75; P=0.002 for superiority). Stent thrombosis was infrequent, and the incidence was similar in the two groups. The incidence of serious adverse events appeared to be similar in the two groups.Conclusions Among low-risk patients with acute myocardial infarction who had undergone early complete revascularization and had completed 1 month of dual antiplatelet therapy without complications, P2Y12-inhibitor monotherapy was noninferior to continued dual antiplatelet therapy with respect to the occurrence of adverse cardiovascular and cerebrovascular events and resulted in a lower incidence of bleeding events. (Funded by MicroPort [France]; TARGET-FIRST ClinicalTrials.gov number, NCT04753749.)In low-risk patients with MI and early complete revascularization, stopping aspirin after 1 month and continuing P2Y12 monotherapy was noninferior to dual antiplatelet therapy for ischemic outcomes and led to reduced bleeding at 1 year.