Continued dual antiplatelet therapy versus aspirin monotherapy beyond 12 months after drug eluting stent implantation: a systematic review and meta-analysis with trial sequential analysis

DAPT continuation beyond 12 months post-DES implantation in event free patients remains unresolved; prior meta-analyses pooled heterogeneous durations and used P2Y12, not aspirin, as comparator. Four databases were searched through August 2026 for RCTs of continued DAPT vs. aspirin monotherapy in event free patients at 1 year post-stenting, with prespecified duration and P2Y12 subgroups and TSA. Post-hoc subgroup analyses by baseline ischemic risk and patient ethnicity, and an incidence rate ratio sensitivity analysis accounting for differential follow up duration, were also performed. Six RCTs ( N = 28,601) were included. Extended DAPT showed no MACCE benefit (RR 0.89, 0.72–1.10) or bleeding (RR 1.19, 0.66–2.14), but reduced non-fatal MI (RR 0.60, 0.51–0.71; only outcome crossing TSA boundary), consistent across strata; a two trial P2Y12 interaction was hypothesis generating; remaining endpoints inconclusive. Incidence rate ratio sensitivity analysis confirmed these findings were not affected by differential follow up duration. Exploratory post-hoc subgroup analyses revealed significant interactions by baseline ischemic risk and patient ethnicity for all-cause mortality and MACCE, with extended DAPT trending toward benefit in higher risk and non-East Asian trials and toward a null or harmful effect in lower risk and East Asian trials. Extended DAPT beyond 12 months lowers non-fatal MI risk without a confirmed net effect on ischemic or bleeding outcomes; first review with prespecified duration/P2Y12 stratification and TSA. Exploratory analyses further suggest this ischemic benefit may vary by baseline ischemic risk and patient ethnicity, a hypothesis generating signal warranting confirmation in future trials. Summary of the study design, meta-analysis outcomes, key subgroup findings, and principal conclusions for continued dual antiplatelet therapy versus aspirin monotherapy beyond 12 months after drug eluting stent implantation