P2Y12 Inhibitor Monotherapy Versus Conventional Dual Antiplatelet Therapy or Aspirin Monotherapy in Acute Coronary Syndrome: A Pooled Analysis of the SMART-DATE and SMART-CHOICE Trials

Controversy remains regarding the optimal antiplatelet regimen in patients with acute coronary syndrome (ACS). This study sought to investigate the efficacy and safety of P2Y12 inhibitor monotherapy compared with conventional dual antiplatelet therapy (DAPT) and aspirin monotherapy in patients with ACS undergoing percutaneous coronary intervention. Data on 4,453 patients were pooled from SMART-DATE and SMART-CHOICE randomized trials. Antiplatelet therapy regimens were categorized as P2Y12 inhibitor monotherapy (P2Y12 inhibitor monotherapy after 3-month DAPT), conventional DAPT (12-month or longer DAPT), and aspirin monotherapy (aspirin monotherapy after 6-month DAPT). The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE, a composite of all-cause death, myocardial infarction, and stroke). Inverse-probability of treatment-weighted (IPTW) analysis was performed. At 1 year, patients in the P2Y12 inhibitor monotherapy had a comparable risk of MACCE compared with those in the conventional DAPT (IPTW-adjusted hazard ratio [HR], 0.655; 95% confidence interval [CI] 0.393 to 1.094; p = 0.106), and tended to have a lower risk of MACCE than those in the aspirin monotherapy (IPTW-adjusted HR, 0.606; 95% CI, 0.347 to 1.058; p = 0.078). The adjusted hazard for the Bleeding Academic Research Consortium (BARC) type 2 to 5 bleeding was significantly lower in P2Y12 inhibitor monotherapy than in conventional DAPT (IPTW-adjusted HR, 0.341; 95% CI, 0.190 to 0.614; p < 0.001) and in aspirin monotherapy (IPTW-adjusted HR, 0.359; 95% CI, 0.182 to 0.708; p = 0.003). In conclusion, among patients with ACS undergoing PCI, P2Y12 inhibitor monotherapy after 3-month DAPT reduced risk of bleeding compared with conventional DAPT and aspirin monotherapy after 6-month DAPT without increasing MACCE.