Impact of Platelet Reactivity on Long-term Clinical Outcomes and Bleeding Events in Japanese Patients Receiving Antiplatelet Therapy with Aspirin

Abstract

Aim:Aspirin is an antiplatelet drug widely used for the prevention of cardiovascular disease; however, it is known to increase bleeding events. A low response to aspirin was reported to correlate with poor prognosis in patients undergoing antiplatelet therapy with aspirin. The aim of this study was to evaluate the impact of the antiplatelet activity of aspirin on cardiovascular and bleeding events in Japanese patients. Methods: We analyzed the clinical course of 239 Japanese patients undergoing antiplatelet therapy with aspirin for a median of 64 months in this study. Their residual platelet reactivity was examined at enrollment and after 2 years. The co-primary endpoints were the occurrence of major adverse cardiac and cerebrovascular events (MACCEs) and bleeding events. Results: The annual incidence of MACCEs and major bleeding events was 3.7% and 0.48%, respectively. With defined criteria, 67 patients (28%) were classified as low responders based on the platelet aggregability measured at enrollment. Low response to aspirin was not associated with increased MACCEs, while it clearly increased MACCEs in patients less than 70 years old (low responders 36.9% vs. responders 14.8%, log rank p=0.008). Five major types of bleeding occurred in the responders, but not in low responders, although the difference was not statistically significant (p = 0.07). Conclusion: Low response to aspirin was not associated with the increase of long-term MACCEs, while it increased MACCEs in patients less than 70 years old; however, it tended to decrease major bleeding events in Japanese patients.

A Short-Term Effect of Low-Dose Aspirin on Major Hemorrhagic Risks in Primary Prevention: A Case-Crossover Design

“…There is a wide reported variation in response to antiplatelet treatment in different ethnic groups (0.4 to 35%) [24]–[26]. While a high response to aspirin might represent good prognosis in patients undergoing antiplatelet treatment, it may also point to greater risk of bleeding events in the same patients [3], [24].…”

“…While a high response to aspirin might represent good prognosis in patients undergoing antiplatelet treatment, it may also point to greater risk of bleeding events in the same patients [3], [24]. In Japan, Morimoto et al , using existing published data on the rates of coronary heart disease, hemorrhagic stroke, and major gastrointestinal bleeding from the Japanese population, found that the benefit of aspirin use only outweighed risk in subjects older than 40 years who had both diabetes and hypertension [3].…”

The prognostic utility of tests of platelet function for the detection of ‘aspirin resistance’ in patients with established cardiovascular or cerebrovascular disease: a systematic review and economic evaluation

“…[265][266][267] Although the authors of this report were aware of these publications, these have not been included in the above analysis to prevent the introduction of bias. A robust approach would be to update all the searches; however, given the magnitude and complexity of this project, this was beyond the resources available.…”

A short-term risk–benefit analysis of occasional and regular use of low-dose aspirin in primary prevention of vascular diseases: a nationwide population-based study

“…The antiplatelet effect of aspirin is wide across different ethnic groups, ranging from 0.4% to 35%. 32–34 A high response to aspirin might suggest a good prognosis for antiplatelet treatment in patients, but it might also represent a greater risk of bleeding events in the same patients. 3 32 Using the existing published data on the rates of coronary heart disease, haemorrhagic stroke and major GI bleeding in the Japanese population, Morimoto et al 3 found that the benefit of aspirin use only outweighed the risk in subjects above the age of 40 years who had both diabetes and hypertension.…”

“… 32–34 A high response to aspirin might suggest a good prognosis for antiplatelet treatment in patients, but it might also represent a greater risk of bleeding events in the same patients. 3 32 Using the existing published data on the rates of coronary heart disease, haemorrhagic stroke and major GI bleeding in the Japanese population, Morimoto et al 3 found that the benefit of aspirin use only outweighed the risk in subjects above the age of 40 years who had both diabetes and hypertension. Consistent with our previous case–crossover study, 9 the present study also found an increased risk of aspirin-associated bleeding in subjects with and without hypertension or diabetes, and found risk to be even higher in people aged ≥65 years.…”