The optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation has not been established yet. The objectives of this study were to evaluate the optimal duration of DAPT after the DES implantation.

From three randomized controlled trials investigating DAPT duration after coronary stent implantation, we evaluated the clinical outcomes of short-term (6 months or less) DAPT compared with prolonged DAPT (12 months or more) in 1661 DES-treated pairs matched by propensity scores. At follow-up of 1 year, net adverse clinical event (NACE) was defined as cardiac death, myocardial infarction, target vessel revascularization, definite/probable stent thrombosis, or thrombolysis in myocardial infarction major bleeding.

Short-term DAPT as compared with prolonged DAPT was not associated with 1-year NACEs after DES implantation [hazard ratio (HR) 1.068, 95 % confidence interval (CI) 0.787–1.450, p = 0.671]. Predictors for NACEs were old age (>75 years), hypertension, diabetes mellitus, renal dysfunction (serum creatinine ≥2.0 mg/dL), and multi-vessel disease. The DAPT strategy differentially contributed to the occurrence of NACEs according to the risk burden (p for interaction <0.001). In patients with low risk for NACEs, bleeding events were less in short-term DAPT than in prolonged DAPT (HR 0.332, 95 % CI 0.130–0.849, p = 0.021) (p for interaction = 0.098). Meanwhile, short-term DAPT was associated with more ischemic events that included cardiac death, myocardial infarction, target vessel revascularization, or definite/probable stent thrombosis (HR 2.164, 95 % CI 1.340–3.494, p = 0.002) (p for interaction <0.001) in patients with high risk for NACEs.

One-year clinical outcomes of DAPT after DES implantation depended on the burden of cardiovascular risk.