Impact of Body Mass Index on Platelet Aggregation After Administration of a High Loading Dose of 600 mg of Clopidogrel Before Percutaneous Coronary Intervention

This study assessed the effect of body mass index (BMI) on platelet aggregation after administration of a high loading dose of clopidogrel 600 mg. Blood samples of 402 patients before percutaneous coronary intervention were collected ≥2 hours after administration of clopidogrel 600 mg. Platelet aggregation was measured in response to adenosine diphosphate (ADP; 5 and 20 μM). Patients were categorized as normal weight (BMI <25 kg/m2) or overweight (BMI ≥25 kg/m2). ADP-induced platelet aggregation was significantly higher in overweight patients than in normal-weight patients (46.0 ± 21.8% vs 38.2 ± 19.3% for ADP 5 μM, p = 0.0007; 55.1 ± 22.7% vs 45.2 ± 21.7% for ADP 20 μM, p <0.0001). Multivariate analyses demonstrated high BMI as the only independent predictor for increased ADP-induced platelet aggregation (p ≤0.005). In conclusion, administration of a single high loading dose of clopidogrel 600 mg does not inhibit platelet aggregation in overweight patients to the same extent as in normal-weight patients.