Higher aspirin dose no more effective for CV prevention in high-risk patients with diabetes

Higher doses of aspirin do not improve outcomes in patients with diabetes and atherosclerotic cardiovascular disease (ASCVD), according to a recent study.

Researchers performed a subgroup analysis of the ADAPTABLE (Aspirin Dosing: A Patient-Centric Trial Assessing Benefits and Long-Term Effectiveness) Trial, an open-label, pragmatic study in which patients with stable, chronic ASCVD were randomly assigned to receive 81 mg or 325 mg of aspirin daily. The goal of the study was to determine the effects of aspirin dosing on a primary effectiveness outcome of all-cause death, hospitalization for myocardial infarction, or hospitalization for stroke, as well as a primary safety outcome of hospitalization for major bleeding. The results were published Sept. 15 by Diabetes Care.

Overall, 15,076 patients were included in the subgroup analysis, 5,676 (39%) with diabetes. Median age for all patients was 67.5 years, and 31.1% were women. Among patients with diabetes, 2,820 (49.7%) were assigned to receive 81 mg of aspirin and 2,856 (50.3%) were assigned to receive 325 mg. Median follow-up was 26.2 months. Rates of the primary effectiveness outcome (9.6% vs. 5.9%; P<0.001) and the primary safety outcome (0.78% vs. 0.50%; P<0.001) were both higher in patients with diabetes. However, among patients with diabetes, neither the primary effectiveness outcome (9.3% vs. 10.0%; hazard ratio [HR], 0.98 [95% CI, 0.83 to 1.16]; P=0.265) nor the safety outcome (0.87% vs. 0.69%; subdistribution HR, 1.25 [95% CI, 0.72 to 2.16]; P=0.772) differed with lower versus higher aspirin doses.

The researchers noted that their findings should be considered hypothesis generating and that the crossover rate in ADAPTABLE between aspirin doses was high, among other limitations. “This study highlights the increased risk of patients with DM [diabetes mellitus] and concomitant ASCVD and the need to find the most potent preventive therapies while balancing their risk profile in order to mitigate their inherently high cardiovascular risk. With an ongoing change in practice patterns toward use of 81 mg daily aspirin as seen in our study, more evidence is needed to support this important decision,” they wrote. “Our findings suggest that an increased daily dose of aspirin yields no extra clinical benefit, even in a vulnerable patient population with DM and established ASCVD.”