P2Y12 Inhibitor or Aspirin Following Dual Antiplatelet Therapy After Percutaneous Coronary Intervention

It is still unknown which antiplatelet monotherapy should be continued after a period of dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI). The aim of this study was to compare aspirin vs P2Y12 inhibitor (P2Y12-I) monotherapy after dual antiplatelet therapy (DAPT) discontinuation in patients undergoing percutaneous coronary intervention (PCI). Randomized studies enrolling patients undergoing PCI with second-generation drug-eluting stents and comparing aspirin or P2Y12-I monotherapy after DAPT discontinuation vs prolonged DAPT or aspirin vs P2Y12-I monotherapy after DAPT were included. Primary efficacy and safety endpoints were myocardial infarction (MI) and major bleeding (MB), respectively. Point estimates for dichotomous outcomes were pooled using frequentist and Bayesian frameworks. Sensitivity analyses and treatment hierarchy were performed. Nineteen studies encompassing 73,126 patients were included. The transitivity assumption was met. Under the frequentist framework, patients receiving aspirin had a significantly higher risk for MI compared with P2Y12-I monotherapy (risk ratio: 1.32; 95% CI: 1.08-1.62). Compared with DAPT, both monotherapies reduced MB, but only P2Y12-I showed equivalent efficacy in preventing MI. No significant differences in MB, death, and other thrombotic outcomes were observed. However, point estimates for the risk for stent thrombosis and stroke favored P2Y12-I monotherapy. Consistent results were found in a fixed-effects model and the Bayesian framework, with all models having adequate convergence. P2Y12-I vs aspirin monotherapy had the highest probability of being ranked first for reduction of all assessed outcomes. P2Y12-I monotherapy following DAPT discontinuation after PCI is associated with a significantly lower risk for MI and similar risk for MB, suggesting a potentially relevant net clinical benefit vs aspirin monotherapy. These findings strengthen the rationale for further studies directly comparing the 2 monotherapies after DAPT in PCI patients.