P2Y12 Inhibitor-Based Single Antiplatelet Therapy Versus Conventional Dual Antiplatelet Therapy After Newer-Generation Drug-Eluting Stent Implantation in Chronic and Acute Coronary Syndromes: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

BACKGROUND: P2Y(12) inhibitor-based single antiplatelet therapy (SAPT) after drug-eluting stent implantation reduces major bleeding without increasing the risk of major adverse cardiovascular and cerebral events compared with 12-month dual antiplatelet therapy (DAPT). The differential effects of P2Y(12) inhibitor monotherapy compared with conventional DAPT in patients with chronic coronary syndromes versus acute coronary syndromes (ACS) remain uncertain. METHODS AND RESULTS: PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched for randomized controlled trials comparing oral P2Y(12) inhibitor-based SAPT after <= 3 months DAPT versus 12-month DAPT after newer-generation drug-eluting stent implantation. Patients were categorized based on baseline presentation (chronic coronary syndromes versus ACS). The co-primary end points were major bleeding and major adverse cardiovascular and cerebral events, a composite of all-cause death, myocardial infarction, or ischemic stroke. A total of 43 945 (ACS, 28 360, 65%) patients from 7 randomized controlled trials were included. At a median follow-up of 12 months, P2Y(12) inhibitor-based SAPT was associated with a lower risk of major bleeding (risk ratio [RR], 0.63 [95% CI, 0.48-0.82]; P<0.001) compared with 12-month DAPT. The risk of major bleeding was significantly lower among patients with ACS (RR, 0.55 [95% CI, 0.40-0.75]; P<0.001). Compared with standard DAPT, P2Y(12) inhibitor-based SAPT was associated with a similar risk of major adverse cardiovascular and cerebral events (RR, 0.98 [95%CI, 0.87-1.11]; P=0.74) among patients with chronic coronary syndromes and ACS. There was no significant interaction between treatment effect and baseline presentation. CONCLUSIONS: Compared with 12-month DAPT, P2Y(12) inhibitor-based SAPT after newer-generation drug-eluting stent implantation is associated with a lower risk of major bleeding without increasing the risk of major adverse cardiovascular and cerebral events, a difference primarily driven by patients with ACS.