Validation of DAPT score for prolonged dual antiplatelet therapy in patients with acute myocardial infarction

INTRODUCTION: Dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) reduces the rate of ischemic events but increases bleeding risk. DAPT score helps identify patients who benefit from prolonged DAPT. Nevertheless, its accuracy in patients with acute myocardial infarction (AMI) remains uncertain. The aim of this study was to validate the use of DAPT score to predict ischemic and bleeding events in patients undergoing PCI for AMI and who received prolonged DAPT. MATERIAL AND METHODS: This study included a cohort of patients with AMI who underwent PCI with stent placement and were treated with DAPT for more than 12 months. RESULTS: Two hundred thirty subjects were included in the final analysis (age: 64 ± 12 years, 78% men, median follow-up: 31 months). Ischemic event (reinfarction or revascularization of target vessel or lesion) occurred in 17% and bleeding occurred in 5% of patients. DAPT score demonstrated modest prediction performance for ischemic events (C-statistic: 0.59, 95% confidence interval [CI]: 0.50-0.68, p<0.001) and a good prediction performance for bleeding events (C-statistic: 0.79, 95% CI: 0.66-0.92, p<0.001). Subjects with a DAPT score ≥2 had a greater risk of ischemic events (hazard risk [HR]: 3.1, 95% CI: 1.2-7.8, p = 0.019) and a lower risk of bleeding (HR: 0.23, 95% CI: 0.07-0.79, p = 0.019). Kaplan-Meier curves at 4 years showed that patients with a DAPT score ≥2 had lower ischemic-free survival rates (79% ± 4 vs. 90% ± 5, p = 0.0137) and higher bleeding-free survival rates (97% ± 2 vs. 90% ± 4, p = 0.0106). CONCLUSIONS: DAPT score is useful in patients with AMI, and a cut-off value of 2 identifies patients with a higher risk of ischemic events who might benefit from prolonged DAPT.