Despite having no greater chance of developing problems after high risk cardiovascular surgery, women are more likely than men to die from postoperative complications, a University of Michigan-led study suggests.

A patient dying of complications after surgery is often referred to as a “failure to rescue”. 

Investigators assessed more than 850,000 cases of Medicare beneficiaries who had high risk heart surgery — including heart bypass, aortic aneurysm repair, and mitral and aortic valve repair — between 2015 and 2020. 

Men and women had a similar rate of complications after an operation, around 15%. 

However, women died of those complications at a significantly higher rate: Surgical teams failed to rescue female patients 10.7% of the time, compared to 8.6% for male patients. 

The results are published in JAMA Surgery. 

“This is an issue for the entire United States health care system: we are failing to rescue women after high risk surgery even though the rate of postoperative complication is similar to men,” said Catherine M. Wagner, M.D., M.Sc., first author and an integrated thoracic surgery resident at University of Michigan Health.

“There needs to be improved recognition and response to these complications if we are to narrow the sex disparities after high risk surgery.”

Researchers found a similar pattern in the failure to rescue rate for each individual procedure. 

The most common complications for men and women were kidney failure, pneumonia and lung failure.

The quality of a hospital where the procedure was performed did not affect the failure to rescue disparity between sexes.

In fact, women in the study were more likely to receive surgery at hospitals that, traditionally, take on a higher volume of high risk surgeries. 

“These high risk procedures are inherently expected to have higher complication rates, but patients are still expected to have a positive outcome if the complication is managed quickly,” said co-author Gorav Ailawadi, M.D, M.B.A., chair of cardiac surgery at U-M Health and a director of the University of Michigan Health Frankel Cardiovascular Center.

“In our study, female patients had a lower rate of reoperation than males,” he added, using a term to mean a second operation within days of the first.

“This may not be due to a lower need for reoperation; it could instead be a signal that their complications were not appropriately addressed.”

For years, researchers have shown that women are more likely to die after cardiovascular surgery.  

The explanation, so far, has largely centered around that fact that women are older when they receive surgery and have more comorbidities than men. 

Women also have smaller anatomy and vessel size, which can make surgery more technically difficult.

This disparity is in addition to previous studies that have found that signs and symptoms of common disease, such as heart attack and stroke, are more often either missed or not taken seriously for female patients. 

“After accounting for patient comorbidities and patient risk, we found that men and women had similar rates and types of complications; however, women remained more likely to die from those complications,” said co-author Andrew Ibrahim, M.D., M.Sc., associate professor of surgery at U-M Medical School and co-director of the Michigan Medicine Center for Healthcare Outcomes and Policy. 

“In addition to reducing complications overall, we must focus on what happens after a complication occurs. Similarly, we have an opportunity after surgery to improve early recognition when a female patient is having a complication before it cascades to a point where we cannot rescue them. Improving the recognition and response to postoperative complications, especially for women, is needed to reduce longstanding disparities on outcomes after high risk surgery.” 

For years, women have been underrepresented in medical research. 

In June 2016, the National Institutes of Health installed a policy that called for sex as a biological variable to be factored into research designs, analyses and reporting.

“In addition to taking steps at a health system level to reduce this disparity, we must continue to examine sex differences in biomedical research to address the longstanding neglect of women’s health and identify underlying mechanisms that, if addressed, can improve outcomes for all patients,” Wagner said.

Additional authors: Karen E. Joynt Maddox, M.D., M.P.H., of Washington University School of Medicine.

Paper cited: “Failure to Rescue Females Undergoing High-Risk Surgery,” JAMA Surgery. DOI: 10.1001/jamasurg.2024.4574.

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