Clinical outcomes of dual antiplatelet therapy after implantation of drug-eluting stents in patients with different cardiovascular risk factors

Background: 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. Methods: 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. Results: 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. Conclusion: One-year clinical outcomes of DAPT after DES implantation depended on the burden of cardiovascular risk.