Dual Antiplatelet Therapy with 3 rd Generation P2Y 12 Inhibitors in STEMI Patients: Impact of Body Mass Index on Loading Dose–Response

Purpose This study aims to assess the association between body mass index ( BMI ) and platelet reactivity in STEMI patients treated with oral 3 rd generation P2Y 12 inhibitors. Methods Overall, 429 STEMI patients were enrolled in this study. Patients were divided into two groups according to BMI ( BMI < 25 vs ≥ 25 kg/m 2 ). A propensity score matching (1:1) was performed to balance potential confounders in patient baseline characteristics. Platelet reactivity was assessed by VerifyNow at baseline and after 3 rd generation P2Y 12 inhibitor (ticagrelor or prasugrel) loading dose (LD). Blood samples were obtained at baseline (T0), 1 h (T1), 2 h (T2), 4–6 h (T3), and 8–12 h (T4) after the LD. High on-treatment platelet reactivity (HTPR) was defined as a platelet reactivity unit value ≥ 208 units. Results After propensity score matching, patients with BMI ≥ 25 had similar values of baseline platelet reactivity, while they had higher level of platelet reactivity at 1 and 2 h after the LD and higher rate of HRPT. Furthermore, multivariate analysis demonstrated that BMI ≥ 25 was an independent predictor of HTPR at 2 h (OR 2.01, p = .009). Conversely, starting from 4 h after the LD, platelet reactivity values and HRPT rates were comparable among the two study groups. Conclusions A BMI ≥ 25 kg/m 2 is associated with delayed pharmacodynamic response to oral 3 rd generation P2Y 12 inhibitor LD, and it is a strong predictor of HTPR in STEMI patients treated by dual antiplatelet therapy with ticagrelor or prasugrel.