Validating Utility of Dual Antiplatelet Therapy Score in a Large Pooled Cohort From 3 Japanese Percutaneous Coronary Intervention Studies

Abstract

Background: The dual antiplatelet therapy (DAPT) score was developed to estimate ischemic and bleeding risks from the DAPT study. However, few studies validated its utility externally. We sought to validate the utility of the DAPT score in the Japanese population. Methods: In a pooled cohort of 3 studies conducted in Japan (the CREDO-Kyoto [Coronary Revascularization Demonstrating Outcome Study in Kyoto] Registry Cohort-2, RESET [Randomized Evaluation of Sirolimus-Eluting Versus Everolimus-Eluting Stent Trial], and NEXT [NOBORI Biolimus-Eluting Versus XIENCE/PROMUS Everolimus-Eluting Stent Trial]), we compared risks for ischemic and bleeding events from 13 to 36 months after percutaneous coronary intervention among patients with a DAPT score ≥2 (high DS) and a DAPT score <2 (low DS). Results: Among 12 223 patients receiving drug-eluting stents who were free from ischemic or bleeding events at 13 months after percutaneous coronary intervention, 3944 patients had high DS and 8279 had low DS. The cumulative incidence of primary ischemic end point (myocardial infarction/stent thrombosis) was significantly higher in high DS than in low DS (1.5% versus 0.9%, P =0.002), whereas the cumulative incidence of primary bleeding end point (GUSTO moderate/severe) tended to be lower in high DS than in low DS (2.1% versus 2.7%, P =0.07). The cumulative incidences of cardiac death, myocardial infarction, and stent thrombosis were also significantly higher in high DS than in low DS (2.0% versus 1.4%, P =0.03; 1.5% versus 0.8%, P =0.002; 0.7% versus 0.3%, P <0.001, respectively), whereas the cumulative incidences of noncardiac death and GUSTO severe bleeding were significantly lower in high DS than in low DS (2.4% versus 3.9%, P <0.001; 1.0% versus 1.6%, P =0.03, respectively). Conclusions: In the current population, the DAPT score successfully stratified ischemic and bleeding risks, although the ischemic event rate was remarkably low even in high DS. Further studies would be warranted to evaluate the utility of prolonged DAPT guided by the DAPT score.