'Wake-up call': Women are more likely than men to die of complications after heart surgery

Women are more likely than men to die of complications from high-risk cardiovascular surgery, a new study finds.

These life-threatening complications, such as heart attacks and infections, were more likely to be recognized too late in women than in men, resulting in the higher death rate seen in women. Not recognizing or responding quickly enough to complications is referred to as "failure to rescue" by doctors.

The new study, published Oct. 16 in the journal JAMA, analyzed the medical records of more than 860,000 patients who had undergone high-risk surgical procedures between October 2015 and February 2020. All of the procedures involved the heart or blood vessels, including surgeries to repair aneurysms, heart bypass surgeries, and heart-valve replacements.

Overall, about 15% of these patients experienced some complication following their procedure; a similar rate of complications was seen in men and women. But, of the overall group, nearly 11% of the women died of complications, compared with 8.6% of the men. The researchers concluded that this difference was likely caused by delays in doctors recognizing and treating women's complications, which included heart attacks, blood clots in the lungs, kidney failure, lung failure, pneumonia, hemorrhage and surgical-site infections.

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Dr. Mario Gaudino, a cardiac surgeon at Weill Cornell Medical Center and New York Presbyterian Hospital who was not involved in the research, described the study as a "wake-up call" to the long-overlooked disparities in men's and women's outcomes after major surgeries.

Notably, women in the study were also more likely to receive care at teaching hospitals and larger, high-volume hospitals, compared with men. These types of facilities are associated with better-quality care than other medical centers, such as low-volume hospitals — however, women's higher death rate was consistent across all the different facilities.

"If anything, these results show how pervasive the problem is," said Dr. Catherine Wagner, a cardiac surgery resident at the University of Michigan and lead author of the study. "This suggests there is a systemic problem contributing to the under-recognition and under-treatment of women's postoperative complications," Wagner told Live Science in an email.

The study does not draw any definitive conclusions about the factors that might be driving this disparity. Previous research has focused on women's tendency to get surgery at older ages than men, which means they may be dealing with more underlying medical conditions and be at a more advanced stage of disease. These characteristics were reflected in the women in the new study, who, on average, were a bit older and had a slightly higher rate of comorbidities than the men.

However, while these are relevant factors, they fail to fully account for the study's results, which found a much higher death rate among women despite men and women having similar rates and types of complications, said Dr. Andrei Churyla, a cardiac surgeon at Northwestern Medical Group in Chicago who was not involved in the study.

Unconscious bias against women may be one possible explanation, he said. There's a tendency for medical providers to dismiss women's pain, which can delay, or even preclude, proper diagnosis and treatment. A 2022 study in the Journal of the American Heart Association found that young women who complained of chest pain had a 29% longer wait time for heart-attack evaluation than young men, for example.

A lack of understanding of the female heart also may factor into patients' outcomes, Gaudino suggested. "As cardiovascular physicians, I think we've had the wrong approach of thinking that women were actually like men, or just small men," he said. "The mistake we make is to keep treating women with approaches we know work for men."

Until recently, much of the research on cardiac surgery has focused overwhelmingly on male populations, and few studies have been conducted specifically in female patients, Gaudino said.

Additionally, the diagnostic criteria for complications were developed based on data from male patients, so these may fail to account for differences in women's baseline physiology and how these complications manifest in them. As an example, high levels of troponin, a protein in heart muscles, signal a heart attack is coming on — but the cutoff for what counts as "high" was derived mostly from men, who have higher baseline troponin levels than women, he said.

Gaudino suspects the female body is still misunderstood by physicians and that this means complications that would be flagged easily in male patients are more likely to go unnoticed, and thus untreated, in female patients.

There's been a recent effort to shore up research in this area to better understand and address the gap in surgical outcomes between men and women.

"I think we have to constantly remind ourselves that women are different from men," said Dr. Brittany Zwischenberger, a cardiac surgeon at Duke Health in Durham, North Carolina. "And our current focus on sex and gender will hopefully result in tailored approaches to surgery and their postoperative course, and ultimately reduce disparities. But really, this [study] is an opportunity for us to improve postoperative care for all patients."

This article is for informational purposes only and is not meant to offer medical advice.

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