Impact of obesity on response to thienopyridine and bleeding risk in patients treated after acute coronary syndrome by clopidogrel or prasugrel

Background: Variability of response to thienopyridine has been described for both clopidogrel and prasugrel. The aim of the present study was to analyze the impact of Body Mass Index (BMI) and different type of obesities on response to clopidogrel and prasugrel after Actue Coronary Syndrome (ACS).

Methods and results: 1542 ACS consecutive patients undergoing coronary stenting were included including 287 with clopidogrel 75 mg, 868 patients with clopidogrel 150 mg and 387 patients with prasugrel 10 mg. 336 patients (21.8%) were obese (BMI > 30) including 264 obesity type 1 (3040). Among, 1206 non obese patients, we identified 1.6% (n=24) underweight patients (BMI <18.5), 33.4 (n=515) patients with normal BMI and 42.9% (n=429) overweight patients. We observed a stepwise increase of on-treatment platelet reactivity according to the different groups with higher platelet reactivity in patients with higher BMI with all thienopyridine regimens (Figure 1). Using the predefined cut-off of VASP >50% to define the HTPR, incidence of HTPR was higher in obese patients than in non obese patients with all regimens (p<0.05 for all) (Figure 2). Using PRI VASP <20% to define LTPR on prasugrel linked with higher risk of bleeding, the incidence of LTPR was lower in obese patients: 13% (12/93) vs. 33% (97/294), OR [95% CI]: 0.30 [0.16-0.58], p<0.001. Accordingly, incidence of BARC bleeding complications was higher in non obese than in obese patients: 10% (119/1206) vs. 6% (20/336), OR [95% CI]: 1.7 [1.1-2.8], p=0.03.

Conclusion: BMI has a strong impact on response to thienopyridine with a linear relationship between BMI and on treatment platelet reactivity. We also reported in obese patients higher incidence of HTPR, lower incidence of LTPR and lower incidence of bleeding complications.

Source: congress365.escardio.org