LAUSR

OBJECTIVES To assess the external validity of the Dual Antiplatelet Therapy (DAPT) score decision tool in real world patients. METHODS AND RESULTS Retrospective study using an all comers PCI registry. We compared the rates of myocardial infarction (MI) and actionable bleeding between 12 vs. 12+ months DAPT stratified by DAPT score category. Of 12,162 patients, 4471 (36.8%) completed a year of DAPT without events. The high DAPT score stratum patients were older and had a higher comorbidity burden. Overall, 12+ months DAPT duration was associated with reduced rates of MI (2.8% vs. 4.0%, p = 0.025) and similar rates of bleeding (2.6% vs. 1.9%, p = 0.281) compared to 12 months DAPT, but when stratified by DAPT score stratum, there was no difference in any of the outcomes in both high score group, (3.7% vs. 5.3%, p = 0.111 and 2.0% vs. 1.8%, p = 0.800, for MI and bleeding, respectively) and low score patients (2.7% vs. 3.1%, p = 0.656 and 2.8% vs. 2.0%, p = 0.308, for MI and bleeding, respectively). Overall clinical events (MI + bleeding) was again similar between patients treated with 12+ vs. 12 months DAPT (5.5% vs. 6.2%, p = 0.535 and 5.1% vs. 4.4%, p = 0.503 for high and low DAPT score, respectively). CONCLUSIONS for real world patients completing 1 year of DAPT post PCI, rates of MI, actionable bleeding, and their combination did not differ between those treated with 12+ vs. 12 months DAPT stratified by DAPT score stratum. Clinicians should be aware of the DAPT score's limitations. Further studies examining the validity of the DAPT score in larger cohorts are required.