Impact of Body Mass Index on Clinical Outcomes in Myocardial Infarction Patients Undergoing Coronary Stenting with Dual Antiplatelet Therapy

<b>Background</b>: Dual antiplatelet therapy (DAPT), combining aspirin with a P2Y12 receptor inhibitor (P2Y12i), remains central to the management of acute myocardial infarction (MI), especially in patients undergoing percutaneous coronary intervention (PCI). However, the pharmacodynamic response to antiplatelet therapy may vary with body composition. This study investigates the association between body mass index (BMI) and clinical outcomes in MI patients treated with PCI and DAPT. <b>Methods</b>: This retrospective cohort study analyzed data from 52,119 MI patients treated with coronary stenting from 2014 to 2021, sourced from the Hungarian Myocardial Infarction Registry. Patients were stratified into clopidogrel-based (<i>n</i> = 44,480) and potent P2Y12i-based (prasugrel or ticagrelor; <i>n</i> = 7639) DAPT cohorts. Clinical outcomes-including 12-month mortality and ischemic events-were assessed across BMI categories. Kaplan-Meier analysis and LASSO Cox regression identified predictors of mortality, while decision curve analysis (DCA) evaluated the net clinical benefit of potent P2Y12i across BMI strata. <b>Results</b>: Univariate and multivariate Cox regression analyses identified BMI and potent P2Y12i treatment as significant predictors of 365-day mortality, with higher BMI associated with lower observed rates of mortality, major adverse cardiovascular events (MACEs), and stroke. However, higher BMI was also associated with an increased risk of repeat revascularization and PCI. This study found that the protective effect of potent P2Y12i treatment was consistent across different BMI categories. <b>Conclusions</b>: In patients with MI undergoing PCI, elevated BMI was paradoxically associated with more favorable short-term outcomes, including reduced mortality. Potent P2Y12i therapy demonstrated a consistent benefit across BMI categories, supporting its broad application irrespective of body mass.