Few women participate in studies for common cardiac conditions, according to study

Although cardiovascular disease is a leading cause of death for women, they remain underrepresented in clinical trials for common heart conditions. These findings, by investigators in the Smidt Heart Institute at Cedars-Sinai, were presented at the ESC Congress 2025 in Madrid.

“Numbers don’t lie,” said Martha Gulati, MD, director of Preventive Cardiology in the Smidt Heart Institute and senior author of the paper. “We hope that keeping track of male-to-female participant ratios will motivate researchers to design trials that reflect the real-world population.”

Gulati presented the findings in an oral abstract at the European Society of Cardiology Congress. The results were simultaneously published in JAMA Network Open.

Gulati and colleagues reviewed data from 1,079 cardiovascular clinical trials registered on ClinicalTrials.gov from 2017 to 2023. Women accounted for 41% of the study participants. Investigators found the proportion of women included in clinical trials for certain conditions was much lower than the proportion of women who have these conditions.

The team applied a ratio called the participation-to-prevalence ratio (PPR) to capture whether the percentage of women in a clinical trial reflected how common the condition is among women. The participation-to-prevalence ratios for women were lowest for trials of coronary heart disease, acute coronary syndrome and stroke. Research on obesity and pulmonary hypertension had much higher female participation.

Investigators also found that younger women, ages 19 to 55, were more likely to participate in clinical trials than women 61 or older, and that women tended to enroll in trials studying lifestyle interventions and not trials studying procedures.

“Some studies might stop enrolling once they reach a certain number of people,” Gulati said. “It would be more equitable to continue enrolling until the number of women in the study reflects the proportion of women with that condition.”

The authors also recommend researchers improve outreach efforts to female patients.

“Although we’ve made progress, critical gaps persist,” said study co-author Susan Cheng, MD, MPH, the Erika J. Glazer Chair in Women’s Cardiovascular Health and Population Science in the Smidt Heart Institute. “It’s important to ensure that what we learn from research can be applied to women, who represent more than half of the world’s population.”