Laboratory Aspirin Resistance and the Risk of Major Adverse Cardiovascular Events in Patients with Coronary Heart Disease on Confirmed Aspirin Adherence

Aim: Previous meta-analyses have demonstrated an increased risk of adverse events in aspirin-resistant patients. In this meta-analysis, we aimed to update clinical evidence regarding the relationship between aspirin resistance and major adverse cardiovascular events (MACEs) in patients with coronary heart disease (CHD) on confirmed aspirin adherence. Methods: An electronic literature search of PubMed, EMBASE, Web of Science and the Cochrane Library and a hand search of bibliographies through April 2013 were conducted. Studies were included if they prospectively investigated the association between aspirin resistance and the risk of adverse cardiovascular events during follow-up in CHD patients, mentioned confirmed compliance and provided adequate data for a statistical analysis. Results: Nine prospective studies with a total 1,889 CHD patients who were followed for one month to 2.5 years and study sample sizes ranging from 86 to 496 patients were identified. Overall, 622 of the 1,889 CHD patients (33.0%) were classified as being aspirin resistant with confirmed aspirin adherence. The aspirin-resistant patients exhibited a significantly higher risk of adverse events than the aspirin-sensitive patients (odds ratio 2.44, 95% confidence interval 1.81 to 3.30; p<0.00001). Conclusions: Among CHD patients, approximately one in three individuals can be diagnosed as aspirin resistant on confirmed aspirin adherence. Patients identified as having laboratory aspirin resistance exhibit a 2.4-fold increased risk of MACE compared with aspirin-sensitive patients.