Assessment of Risk Factors for Drug Resistance of Dual Anti Platelet Therapy After PCI.

Since aspirin and clopidogrel are the widely and conventionally used drugs to treat acute myocardial infarction after percutaneous coronary intervention (PCI), it is important to explore potential risk factors of their resistance. The platelet aggregation rate with arachidonic acid (AA, PAg-AA%) and adenosine diphosphate (ADP, PAg-ADP%) of 219 PCI patients were measured after standard treatment for 24 h. The disease history and laboratory data (before PCI) were obtained. We found 101 (46.12%) patients to be aspirin-resistant, and PAg-ADP% was the most prominent risk factor of aspirin resistance. Clopidogrel resistance was present in 157 of 219 patients. Patients in the clopidogrel-resistant group carried more CYP2C19*3 or *2, which was associated with higher clopidogrel resistance in this group (69.11%, 47/68) than in the control group (64.29%, 36/56). Platelet count (10/L) and hemoglobin (g/L) were the prominent risk factors of clopidogrel resistance. Among the 219 patients, 98 showed dual antiplatelet drug resistance, for which platelet count (10/L) and monocyte count (g/L) were the risk factors. Aspirin resistance was found to usually accompany clopidogrel resistance.