Three-month versus twelve-month dual antiplatelet therapy after acute coronary syndrome: An updated meta-analysis of randomized trials with trial sequential analysis.
BACKGROUND The optimal duration of dual antiplatelet therapy (DAPT) after acute coronary syndrome (ACS) treated with percutaneous coronary intervention (PCI) remains uncertain. Advances in stent design and the use of potent P2Y₁₂ inhibitors have reduced thrombotic risk, raising questions about whether prolonged DAPT continues to provide incremental benefit. METHODS We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) enrolling exclusively ACS patients undergoing PCI who were randomized to 3-month versus 12-month DAPT. Coprimary outcomes were major adverse cardiovascular and cerebrovascular events (MACCE) and clinically relevant bleeding (CRB). Secondary outcomes included all-cause mortality, myocardial infarction, stroke, stent thrombosis, target-vessel revascularization, and net adverse clinical events (NACE; MACCE + CRB). Trial sequential analysis (TSA) was performed to evaluate the conclusiveness of evidence for each coprimary outcome. RESULTS Seven RCTs encompassing 17,515 patients (mean age 63 years; 31% women; 45% STEMI) were included. Abbreviated 3-month DAPT did not differ from 12-month therapy for MACCE (5.6% vs 5.7%; risk ratio [RR], 0.96; 95% CI, 0.79-1.17; I2 = 44%), but significantly reduced CRB (3.0% vs 4.9%; RR, 0.62; 95% CI, 0.50-0.76; I2 = 31%), corresponding to an absolute risk reduction of 1.9% and number needed to treat of 52. NACE was lower with abbreviated therapy (7.9% vs 9.7%; RR, 0.81; 95% CI, 0.66-1.00). TSA crossed the futility boundary for MACCE and the benefit boundary for CRB, indicating conclusive evidence for bleeding reduction and futility for ischemic benefit. CONCLUSIONS Among ACS patients treated with contemporary DES, 3-month DAPT followed by monotherapy significantly reduces bleeding without increasing ischemic events. TSA confirms the conclusiveness of current evidence, supporting abbreviated DAPT as a safe and effective default strategy in appropriately selected ACS patients. REGISTRATION The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) with unique identifier CRD420251143351 and URL: https://www.crd.york.ac.uk/prospero/search.