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

Abstract

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.

Platelet response to increased aspirin dose in patients with persistent platelet aggregation while treated with aspirin 81 mg

“…One third of these patients exhibited “aspirin resistance,” indicating that over 600 high‐risk patients for a secondary event were not experiencing adequate antiplatelet protection . This is consistent with a meta‐analysis published 6 years earlier, which reviewed 20 studies focused on patients with cardiovascular disease; 28% of the 2930 patients were classified as “aspirin resistant” and from this group, 41% experienced a cardiovascular event, 5.7% died, and 39.4% developed acute coronary syndrome …”

“…Patients whose platelets continue to show aggregation despite aspirin treatment are at a significantly higher risk of ischemic adverse events. There are multiple reports of increased risk for secondary cardiovascular and cerebrovascular events in patients who are “aspirin resistant.” Notably, Li et al showed that aspirin fails to prevent 81% of recurrent serious vascular events in high‐risk patients who are “aspirin resistant.” In the most recent meta‐analysis published in 2014 evaluating 1889 patients with coronary heart disease, “aspirin resistance” increased the risk of recurrent adverse cardiovascular events. One third of these patients exhibited “aspirin resistance,” indicating that over 600 high‐risk patients for a secondary event were not experiencing adequate antiplatelet protection .…”

“…Notably, Li et al showed that aspirin fails to prevent 81% of recurrent serious vascular events in high-risk patients who are "aspirin resistant." 5 In the most recent meta-analysis published in 2014 evaluating 1889 patients with coronary heart disease, "aspirin resistance" increased the risk of recurrent adverse cardiovascular events. One third of these patients exhibited "aspirin resistance," indicating that over 600 high-risk patients for a secondary event were not experiencing adequate antiplatelet protection.…”

“…6 This is consistent with a meta-analysis published 6 years earlier, which reviewed 20 studies focused on patients with cardiovascular disease; 28% of the 2930 patients were classified as "aspirin resistant" and from this group, 41% experienced a cardiovascular event, 5.7% died, and 39.4% developed acute coronary syndrome. 5 We have previously shown that in an ambulatory population of patients who had suffered a transient ischemic attack or cerebral infarction, approximately 75%-80% obtain an adequate antiplatelet response to aspirin 81 mg daily. In the remaining 20% of this population, 81 mg daily produced little to no antiplatelet response.…”

Aspirin resistance in coronary heart disease: Current understandings and strategies

“…Even in CHD patients who were well-compliant to aspirin therapy, aspirin resistance can increase the risk for MACEs by 2.4 times. [17] …”