Women may face heart surgery delays due to criteria based on male anatomy

Women may receive heart procedures later due to surgical criteria based off male anatomy, two Michigan Medicine-led studies suggest.

Researchers found that size thresholds surgeons use to determine whether to move forward with certain operations do not consider smaller female cardiac structures — which may result in delays for women.

“Most size thresholds for surgical intervention are absolute, and our findings suggest that this may contribute to women undergoing surgery later and sicker, or being less likely to receive recommended surgical therapy,” said Catherine M. Wagner, M.D., M.Sc., first author of both studies and integrated thoracic surgery resident at the University of Michigan Health Frankel Cardiovascular Center.

“The results highlight a need for sex-specific guideline criteria, or criteria that account for differing body size, to improve timely intervention on women with cardiovascular disease and ultimately improve outcomes.

In the first of two studies, U-M researchers investigated thousands mitral valve surgery cases between mid-2014 and 2023 using the Society of Thoracic Surgeons national database.

They focused on the mitral valve surgery patients who also experienced leaking, or regurgitation, from their tricuspid valve.

Some patients are recommended to have the tricuspid valve repaired during the same procedure depending on the severity of the leakage and if their tricuspid annulus is dilated beyond a size threshold of 40 mm.

Results published in the Journal of the American College of Cardiology reveal that women were more likely to have severe tricuspid regurgitation than men but less likely to undergo repair.

A reason for this, researchers believe, is because women had smaller absolute tricuspid annulus dilation compared to men.

“There was no difference in the rate of who received tricuspid repair when the tricuspid annulus reached the standard surgical threshold of 40 mm, but we are seeing that using an absolute diameter across all patients may be inadequate,” said Steven F. Bolling, senior author and professor of cardiac surgery at University of Michigan Medical School.

The second paper, published in Heart, assessed patients who underwent spontaneous repair for acute type A aortic dissection, a potentially fatal tear in the wall of the body’s largest artery.

Women who experienced dissection had a smaller diameter of the ascending aorta than men but presented with a larger diameter compared to their body size.

The current size threshold for preventive repair of ascending aortic aneurysm — a common cause of aortic emergencies, including dissection, rupture and death — is the same across both sexes at 50 mm.

Women in this study, however, were nearly three times more likely to experience dissection at sizes below that range.

“Our study builds on mounting evidence that sex-agnostic repair guidelines for aortic dissection may inadvertently disadvantage females, leading to a higher rate of preventable aortic complications among women,” said Barbara C.S. Hamilton, M.D., M.S., senior author of the paper and the Cheryl Huey, M.D., Early Career Professor of Cardiac Surgery at U-M Medical School.

For abdominal aortic aneurysm, which can also lead to dissection but is a less common cause, similar studies led to sex-specific intervention guidelines.

“This is one of many opportunities across cardiac surgery to evaluate whether guidelines tailored by sex​ or body-size​ could narrow longstanding sex disparities in cardiovascular disease,” Wagner said.

Additional authors:

Robert B. Hawkins, M.D., Gorav Ailawadi M.D., M.B.A., both of University of Michigan, are authors on both papers.

Prabhvir S. Marway MBBChir, Meganne N. Ferrel M.D., Carlos Alberto Campello Jorge M.D., Shinichi Fukuhara M.D., Robert B. Hawkins, M.D., M.Sc., G Michael Deeb M.D., Himanshu J. Patel, M.D., Gorav Ailawadi M.D., M.B.A., and Bo Yang, M.D., Ph.D., all of University of Michigan, and Nicholas S. Burris M.D., of University of Wisconsin-Madison are additional authors on the published work in Heart.

Funding/disclosures:

Wagner was supported partially through the National Clinician Scholars Program in the Institute for U-M Institute for Healthcare Policy and Innovation.

The Heart study was funded partly by the National Heart, Lung, and Blood Institute (HL170059, HL145953) of the National Institutes of Health.

The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

The Heart study was also partially funded by the Aikens Aortic Discovery Grant, the Frankel Cardiovascular Center, Joe D. Morris Professorship, David Hamilton Fund and the Phil Jenkins Breakthrough Fund.

Papers cited:

“Sex differences in tricuspid repair during mitral surgery: Evaluation of size thresholds in surgical decision making,” Journal of the American College of Cardiology. DOI: 10.1016/j.jacc.2025.08.058

“Sex differences in ascending aortic diameter at time of acute type A aortic dissection,” Heart. DOI: 10.1136/heartjnl-2025-325984

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