To investigate the influence of aspirin and/or clopidogrel treatment on platelet aggregation rate in coronary heart disease (CHD) patients, and discuss the factors related to anti-platelet drug resistance.

A total of 160 patients with CHD and received aspirin and/or clopidogrel treatment were enrolled in the Second Xiangya Hospital, Central South University, and were divided into stable coronary heart disease (SCHD) group (n=90) and acute coronary syndrome (ACS) group (n=70). Meanwhile, non-coronary heart disease (NCHD) patients who did not receive anti-platelet drug treatment were enrolled as controls (n=50). Clinical data of the subjects were recorded. The maximum platelet aggregation rate induced by arachidonic acid (MAR-AA) and adenosine diphosphate (MAR-ADP) were evaluated with sequential platelet counting method. The factors related to drug resistance were analyzed with Logistic regression analysis.

Compared to NCHD group, there were lower MAR-AA and MAR-ADP in two groups of CHD (all P<0.05). In ACS patients, MAR-AA and MAR-ADP are significantly lower (P<0.05) in patients who receive the aspirin and clopidogrel. The rate of anti-platelet drug resistance in ACS group was significantly higher than that in SCHD group (20.0% vs 10.0%, P<0.05). Multivariate logistic regression analysis showed that low HDL-C (<1.0 mmol/L) was an independent risk factor related to the anti-platelet drug resistance (OR=4.36, 95% CI: 1.36-14.02, P=0.025).

The antiplatelet treatment with aspirin and/or clopidogrel can significantly reduce the platelet reactivity in CHD patients, but some patients still present anti-platelet drug resistance. The combination of aspirin and clopidogrel is better. The rate of drug resistance in ACS patients is high. Low HDL-C might be associated with anti-platelet drug resistance.

Aspirin/TU; Ticlopidine/AA/TU; Coronary disease/DT; Platelet aggregation/DE; Drug resistance