Addressing the Underrepresentation of Women in Cardiovascular Clinical Trials

Approximately 60 million women in the United States are affected by CVD, but only about 44% of them recognize CVD as a serious health threat.¹ This is primarily due to a preference for enrolling men in cardiovascular clinical trials, resulting in under-representation and inadequate treatment options for women with CVD. Despite recognized disparities in treatment and clinical trials between men and women, multiple studies published between 2021 and 2024 found continued challenges with representation in cardiovascular research, such as coronary revascularization trials. Under-representation of women in cardiovascular trials has significant implications for health outcomes and knowledge of women's biology, often limiting their access to antiplatelet therapy and other treatments for CVD.

The low representation of women in cardiovascular clinical trials remains a significant issue with far-reaching implications for both treatment outcomes and our understanding of CVD management.

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Antiplatelet therapy is widely accepted as a treatment for patients with CVD, but the underrepresentation of women in these trials limits our understanding of the efficacy, side effects (AEs), or outcomes of this treatment. JAMA CardiologyThe authors found that among all types of cardiovascular clinical trials conducted between 2010 and 2017, only 27% of women were enrolled in 141 coronary artery disease trials and 61 acute coronary syndrome trials.²

Currently, because male patients are overrepresented in clinical trials, medical professionals have more comprehensive knowledge about men's response to CVD treatment than women. Differences between women and men in hormones, platelet reactivity, P2Y12 inhibitors, and likelihood of developing complications greatly affect response to treatment.³ The increased likelihood of AEs occurring during CVD therapy in women may be due to changes in absorption, body composition, distribution, metabolism, or hormones.^Four These differences not only affect treatment outcomes but also hinder physicians' understanding of optimal dosing, efficacy, and AEs of cardiovascular treatments.

The study was published in Journal of the American Heart Association published an analysis of registry data from 51 randomized trials and found that of a total of 25,425 patients enrolled, only 5,029 were women, accounting for 20.8% of participants (95% CI, 17.6-24.4; range, 0.5%-57.9%).³ Additional studies have reported that CVD therapies and medications often do not report sex-based findings, despite evidence that women experience more adverse reactions to cardiovascular medications compared to men, are 1.5-1.7 times more likely to be at risk, and have higher rates of hospitalization related to cardiovascular events.^Five

Underrepresentation of women in cardiovascular clinical trials is a significant issue with far-reaching implications for both treatment outcomes and our understanding of CVD management. Despite significant progress in awareness, continued disparities in enrollment rates impede efforts to fully understand treatment effects, potential adverse events, and overall health outcomes. Addressing this disparity is not only essential for equitable healthcare, but also to better understand how women and minorities respond to cardiovascular treatments.

References

1. American Heart Association. Facts About Women and Heart Disease. www.goredforwomen.org. 2019. Accessed May 23, 2024. https://www.goredforwomen.org/en/about-heart-disease-in-women/facts

2. Yong CM, Fearon WF. Underrepresentation of women in revascularization trials. JAMA Cardiol. May 8, 2024. doi:10.1001/jamacardio.2024.0768

3. Gaudino M, Di Mauro M, et al. Representation of women in randomized trials in cardiac surgery: a meta-analysis. J. Am Heart AssociationAugust 5, 2021 doi.org/10.1161/JAHA.120.020513

4. How to read the guidelines: The impact of gender differences on cardiovascular treatment Pharmacy Times. June 16, 2023. Accessed May 24, 2024. https://www.pharmacytimes.com/view/reading-between-the-guidelines-how-sex-differences-impact-cardiovascular-therapy

5. Falero M, Bellamkonda L, Gomez-Otero I, Diaz-Molina B. Gender and heart failure treatment prescription and adherence. Front Cardiovascular Medicine. 2021;8:630141. May 7, 2021. doi:10.3389/fcvm.2021.630141