AIMS
Dual antiplatelet therapy (DAPT) is established for acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). Contemporary studies suggest shorter DAPT strategies may reduce bleeding while preserving ischemic protection. We evaluated efficacy and safety of early aspirin discontinuation followed by potent P2Y12 inhibitor monotherapy versus standard 12-month DAPT in ACS patients post-PCI.

METHODS AND RESULTS
We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing 12-month DAPT versus early aspirin discontinuation (1-2 months) following PCI for ACS, excluding immediate aspirin withdrawal (<5 days). We searched PubMed, Embase, and Cochrane databases. RCTs comparing 12-month DAPT versus early aspirin discontinuation (1-2 months) following PCI for ACS were included, excluding immediate withdrawal (<5 days). Individual patient data were reconstructed from published Kaplan-Meier curves using IPDfromKM package in R. Stratified Cox regression estimated pooled hazard ratios (HRs) and 95% confidence intervals (CIs). Primary efficacy endpoint was major adverse cardiac events (MACE: all-cause/cardiovascular mortality, myocardial infarction, target-vessel revascularization, stent thrombosis). Primary safety endpoint was bleeding (BARC 3 or 5, TIMI major). Secondary endpoints included net adverse clinical events (NACE), all-cause mortality, myocardial infarction, stroke, target-vessel revascularization, stent thrombosis, and clinically relevant bleeding (BARC 2, 3 or 5). 
Five RCTs comprising 12,598 patients were included; 6,499 (51.6%) randomized to early aspirin discontinuation. Mean age ranged 60.8-66.8 years, 79% males.  Short-term DAPT showed 59% reduction in bleeding risk (HR 0.41; 95% CI 0.39-0.50; P < 0.0001) while preserving ischemic protection, with no differences in major adverse cardiac events (HR 1.06; 95% CI 0.83-1.33; P=0.65). Early aspirin cessation reduced net adverse clinical events (HR 0.74; 95% CI 0.62-0.88; P < 0.001). Stratified analyses demonstrated 69% reduction in major bleeding (HR 0.31; 95% CI 0.18-0.52; P < 0.01) and 55% reduction in clinically relevant bleeding (HR 0.45; 95% CI 0.34-0.60; P < 0.001). No significant differences for all-cause death (HR 1.26; 95% CI 0.86-1.84), myocardial infarction (HR 1.22; 95% CI 0.76-1.95), stent thrombosis (HR 1.22; 95% CI 0.48-3.12), stroke (HR 0.96; 95% CI 0.64-1.44), or target vessel revascularization (HR 0.85; 95% CI 0.59-1.20) were observed. 

CONCLUSIONS
Early aspirin discontinuation at approximately 1 month, switching to potent P2Y12 inhibitor monotherapy, significantly reduces bleeding and net adverse clinical events while preserving ischemic protection in selected ACS patients post-PCI with contemporary stents.