Reviwer: Dr. Betül Balaban Koçaş

Name of the Study : Aspirin Dosing: A Patient-Centric Trial Assessing Benefits and Long-Term Effectiveness- ADAPTABLE

Published in Congress: ACC 2021

Full Text Link: https://www.nejm.org/doi/full/10.1056/NEJMoa2102137

Background: The dose of aspirin required to reduce the risk of death, myocardial infarction and stroke in people with atherosclerotic cardiovascular disease and to minimize major bleeding is still a controversial issue.

Objective: The aim of the ADAPTABLE study was to find the optimal dose of aspirin (81 mg or 325 mg) required to prevent death, myocardial infarction, and stroke in people with atherosclerotic cardiovascular disease.

Method: By random sampling in the study design, patients with atherosclerotic cardiovascular disease were randomized to either the 81 mg aspirin (n=7540) or 325 mg aspirin (n=7536) arms. The follow-up period of the study was 26.2 months, the mean patient age was 68, and 69% of the study group were male and 38% had diabetes. Patients with cardiovascular disease defined as 1) previous myocardial infarction, 2) previous coronary revascularization, 3) prior known coronary stenosis ≥75%, or 4) history of chronic ischemic heart disease, coronary artery disease, or atherosclerotic cardiovascular disease, accompanied by at least one risk factor were included.

Results: At 12-month follow-up, the primary efficacy endpoint of all-cause death, myocardial infarction, or stroke occurred in 7.3% of the 81 mg aspirin group and 7.5% of the 325 mg aspirin group (p = 0.75). The primary safety outcome, major bleeding requiring blood transfusion, was detected in 0.6% of the 81 mg aspirin group and 0.6% of the 325 mg aspirin group (p = 0.41). The secondary outcome, dose change, was 7.1% in the 81 mg aspirin arm and 41.6% in the 325 mg aspirin arm.

Conclusion: In patients with atherosclerotic cardiovascular disease, no significant difference was found in terms of cardiovascular events or major bleeding with daily use of low-dose (81mg) or high-dose (325mg) aspirin. In addition, patients in the high-dose aspirin arm had significantly higher rates of changing doses or discontinuation of aspirin use.

Interpretation: Although it is thought that the antiplatelet efficacy and bleeding risk will be higher with the use of high-dose aspirin; when the results of the study were examined, no difference was found between the groups in terms of major events and bleeding, and it was shown that high-dose aspirin was not superior. Especially in the high-dose aspirin group, a significant decrease in drug compliance and an increase in the transition to low-dose aspirin were observed. Therefore, in patients with chronic ischemic heart disease, it may be more reasonable to prefer low-dose aspirin in long-term maintenance therapy to increase drug compliance. On the other hand, if the patient was using 81 mg of aspirin before, since there is no difference between the two doses, instead of switching to 325 mg, continue at the same dose; If he is using 325 mg and there is no problem in the follow-up, it may be more appropriate to continue at the same dose.