Validation of the DAPT score in real-world patients undergoing coronary stent implantation

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.