Despite longstanding inclusion policies to increase the enrollment of women in cardiovascular clinical trials, a brief report published Sept. 25 in JACC: Advances confirms that this disparity persists, with women representing only a third of patients in the late-breaking clinical trials (LBCTs) presented at ACC.26.

Isabelle Moseley, MD, Leslee J. Shaw, MD, FACC, et al., used ACC meeting materials, trial publications and ClinicalTrials.gov to identify eligible trials. Trials were included if they enrolled a cardiovascular population, reported the number or percentage of women and were presented from 2016 through 2024. Extension studies, pooled analyses, subgroup reports and post hoc analyses were excluded.

The 113 included LBCTs enrolled 366,953 participants, 32% of whom were women. Across trials, the median percentage of women was 29% (IQR, 24%-44%; range, 11%-88%).

Additionally, the researchers assigned each trial to one of seven clinical domains, calculated weighted enrollment by dividing the total number of women by the total number of participants in each domain and benchmarked enrollment against registries.

The lowest representation of women was in trials of heart failure, acute coronary syndromes and interventional cardiology, at 30%, 25% and 25%, respectively. Women represented 29% of participants in electrophysiology trials, 31% in secondary prevention/high atherosclerotic cardiovascular disease risk trials, 39% in structural/device/cardiothoracic surgery trials and 46% in primary/cardiometabolic prevention trials.

The researchers write that the results support domain-specific recruitment strategies rather than uniform targets. These strategies could include earlier referral pathways, streamlined consent, site-level accountability and enrollment goals informed by populations treated in national registries. Moreover, more consistent prespecification and reporting of sex-specific analyses are needed.

"These findings confirm and extend prior reports by showing persistent sex disparities in a larger, contemporary ACC LBCT cohort and by identifying particularly large registry-benchmarked deficits in [HF], [ACS] and interventional trials," write the authors. "Transparent registry-benchmarked enrollment metrics and routine sex-specific analyses should become standard expectations for cardiovascular LBCTs."