Impact of clinical factors on response to clopidogrel therapy in patients with acute coronary syndrome

Abstract

Background A heterogeneous platelet reactivity response to clopidogrel exists, and the clinical or biochemical predictors of suboptimal response to clopidogrel remain unclear. Objectives The goal of this study was to identify factors associated with higher platelet aggregation following clopidogrel therapy in subjects with acute coronary syndrome (ACS). Methods This study was conducted on 62 subjects with ACS requiring treatment with clopidogrel (75 mg daily for 7 days or more). The subjects were divided into diabetic and non diabetic groups. Chrono-log Aggergometer Series 490 used to estimate platelet aggregation. Factors associated with lower response to clopidogrel were identified. Results A heterogeneous, normally distributed platelet aggregation (mean 38.58 ± 18.6%) was observed in 62 subjects (age 56.13 ± 7.9 years; 66.1% men). Statistical analysis revealed significant increased platelet aggregation in patients with history of coronary artery disease (CAD) (44.17 ± 16.3 vs 31.33 ± 19.17, p = 0.006), hypertension (44.47 ± 18.79 vs 31.43 ± 15.91, p = 0.005) and body mass index (BMI) ⩾ 5 kg/m 2 (42.54 ± 17.6 vs 27.19 ± 17.04, p = 0.004). Diabetic patients demonstrated a trend to lower response to clopidogrel treatment with platelet aggregation (42.87 ± 18.54) compared to non diabetic patients (34.29 ± 17.93) but this did not reach a statistical significance ( p = 0.069). Positive correlations were found between platelet aggregation % and the level of fasting blood sugar ( P p = 0.023) and BMI ( P = 0.005). Conclusions Hypertension, past history of CAD, BMI ⩾25 kg/m 2 and diabetes mellitus are associated with higher platelet aggregation following clopidogrel treatment in patients with ACS. Positive correlations were found between platelet aggregation and the level of fasting blood sugar, body weight and BMI in those patients.