Duration of dual antiplatelet therapy and long-term clinical outcome after coronary drug-eluting stent implantation: landmark analyses from the CREDO-Kyoto PCI/CABG Registry Cohort-2.

BACKGROUND: Optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation has not been yet fully elucidated.

METHODS AND RESULTS: We assessed the influence of prolonged thienopyridine therapy on clinical outcomes with landmark analysis at 4 and 13 months after DES implantation. Among 6802 patients with at least 1 DES implantation in the CREDO-Kyoto Registry Cohort-2, 6309 patients (on thienopyridine, 5438 patients; off thienopyridine, 871 patients) and 5901 patients (on thienopyridine, 4098 patients; off thienopyridine, 1803 patients) were eligible for the 4- and 13-month landmark analyses, respectively. The majority of patients had stable coronary artery disease (73%) and received sirolimus-eluting stents (93%), and approximately 90% of thienopyridine was ticlopidine. Patients taking thienopyridine had more complex comorbidities and more complex lesion and procedural characteristics as compared with patients not taking thienopyridine. After adjusting for confounders, thienopyridine use was not associated with decreased risk for death/myocardial infarction/stroke (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.89-1.43, P=0.32 in the 4-month landmark analysis; HR, 1.14; 95% CI, 0.90-1.45, P=0.29 in the 13-month landmark analysis, respectively), whereas the risk for GUSTO moderate/severe bleeding tended to be higher in patients taking thienopyridine (HR, 1.51; 95% CI, 1.00-2.23, P=0.049 in the 4-month landmark analysis; HR, 1.44; 95% CI, 0.99-2.09, P=0.057 in the 13-month landmark analysis, respectively).

CONCLUSIONS: Prolonged thienopyridine therapy beyond 4 and 13 months appeared not to be associated with reduction in ischemic events but to be associated with a trend toward increased bleeding. Optimal duration of DAPT after DES implantation might be shorter than the currently recommended 1-year interval.