One Month Versus Three Months of Aspirin After Percutaneous Coronary Intervention: A Reconstructed Time-to-Event Analysis

P2Y12-inhibitor monotherapy after abbreviated dual antiplatelet therapy (DAPT) reduces bleeding after percutaneous coronary intervention, but whether aspirin can be stopped after one month rather than three remains uncertain. We reconstructed time-to-event data from published Kaplan-Meier or cumulative-incidence curves of 11 randomised trials (37,443 patients) using the Guyot algorithm, grouped trials by aspirin-withdrawal timing, and analysed within-trial monotherapy-versus-continued-DAPT effects using stratified Cox regression and random-effects meta-analysis across 0 to 30, 30 to 90, and 90 to 360-day intervals. Reconstructed event totals matched published totals exactly for all 12 curves, and reconstructed hazard ratios agreed with published estimates to within 2.2%. Monotherapy approximately halved major or minor bleeding (hazard ratio [HR] 0.51, 95% confidence interval [CI] 0.44–0.59). One-month and three-month withdrawal produced comparable ischaemic-composite effects (risk ratio 0.88, CI 0.75–1.03, and 0.92, CI 0.74–1.15); these trials were not randomised against one another, so comparable estimates do not establish clinical equivalence. The only early excess arose with near-immediate withdrawal, driven entirely by NEO-MINDSET (0 to 30-day interval rate ratio 2.09, CI 1.33–3.28); excluding this trial left no ischaemic excess in the remaining trial. Myocardial infarction (HR 1.02, CI 0.82–1.28) and stent thrombosis (Peto odds ratio 1.19, CI 0.77–1.86) showed no overall excess. These hypothesis-generating findings, derived from reconstructed rather than true individual-participant data and from an indirect comparison across trials, suggest the relevant distinction may be immediate versus deferred aspirin withdrawal rather than one versus three months, though the early hazard rests on a single trial and requires independent replication.