JAMA: No sex-specific differences observed in aspirin for the secondary prevention of ASCVD

A new analysis from the ADAPTABLE clinical trial unveiled no significant difference observed in safety and effectiveness between two aspirin dosages for the secondary prevention of atherosclerotic cardiovascular disease (ASCVD) when analyzed by sex. The findings were published in the JAMA Cardiology.

This open-label, pragmatic, randomized clinical trial was conducted at 40 medical centers and one health plan. It included participants with chronic, stable ASCVD who were randomly assigned to receive either 81 mg or 325 mg of aspirin daily. The study focused on the primary effectiveness outcomes of all-cause mortality, hospitalization for myocardial infarction (MI), or stroke, and the primary safety outcome of hospitalization for major bleeding requiring transfusion.

The study followed a total of 15,076 patients with a median age of 67.6 years, over a median period of 26.2 months. Of these participants, close to 10,352 were male (68.7%) and 4,724 were female (31.3%). The female participants were generally younger, more likely to smoke and have a history of peripheral arterial disease when compared to their male counterparts. The effectiveness outcome including all-cause death and hospitalization for MI or stroke-occurred in 8.1% of female participants and 7.1% of male participants.

The analysis found no significant association by sex for the primary effectiveness endpoint between these two aspirin doses, despite these observed differences in baseline characteristics. Female participants who were taking the 81 mg dose had an adjusted hazard ratio (aHR) of 1.01 when compared to the aHR of male participants as 1.06, with a P interaction term for sex of 0.74, this indicated no significant difference.

In terms of safety, female participants had fewer revascularization procedures but a higher risk of hospitalization for stroke. Also, there was a slightly higher rate of bleeding among female participants in the 81 mg aspirin cohort when compared to the 325 mg cohort, though this difference was not statistically significant. Adherence to the prescribed aspirin dose did not significantly differ between male and female participants.

This secondary analysis found no significant sex-specific differences in the effectiveness and safety of 81 mg versus 325 mg aspirin doses for the secondary prevention of ASCVD events. Overall, these findings suggests that both dosages are equally potential for men and women in the context of ASCVD prevention by offering flexibility in prescription based on patient-specific factors rather than sex.

Source:

Benziger, C. P., Stebbins, A., Wruck, L. M., Effron, M. B., Marquis-Gravel, G., Farrehi, P. M., Girotra, S., Gupta, K., Kripalani, S., Munoz, D., Polonsky, T. S., Sharlow, A., Whittle, J., Harrington, R. A., Rothman, R. L., Hernandez, A. F., & Jones, W. S. (2024). Aspirin Dosing for Secondary Prevention of Atherosclerotic Cardiovascular Disease in Male and Female Patients. In JAMA Cardiology. American Medical Association (AMA). https://doi.org/10.1001/jamacardio.2024.1712