Women Fare Worse After Thoracic Aortic Surgery

Megan Brooks

March 21, 2019

Women fare considerably worse than men after thoracic aortic surgery, suggests a large observational study that identified female sex as an independent predictor of mortality, stroke, and a composite end point of mortality and morbidity.

The findings show that sex-specific issues are important when considering thoracic aortic surgery, say researchers with the Canadian Thoracic Aortic Collaborative (CTAC).

There could be several reasons for the sex differences in outcome, study investigator Michael Chu, MD, associate professor of surgery, Western University, London, Ontario, Canada, told theheart.org | Medscape Cardiology.

Women present at an older age, with more comorbidities, and have larger indexed aortic size, suggesting that they present later in the disease process, he explained.

Also, the aortic pathology might differ between women and men, so that women experience greater aortic wall stiffness resulting in faster aortic growth rates. Finally, women might be prone to increased tissue fragility, which could be a risk with conventional surgical techniques, Chu said.

The study was published online February 13 in Circulation.

The CTAC Experience

Contemporary outcomes after the surgical management of thoracic aortic disease have improved, but the impact of sex-related differences is poorly understood, the authors point out.

They analyzed 1653 patients (30% women) who underwent thoracic aortic surgery with hypothermic circulatory arrest between 2002 and 2017 in 10 institutions in the CTAC.

Outcomes of interest were in-hospital death, stroke, and a modified Society of Thoracic Surgeons-defined composite (STS-COMP) for mortality or major morbidity (stroke, renal failure, deep sternal wound infection, reoperation, prolonged ventilation).

Compared with men, women were older (66 vs 61 years; P < .001) and had more hypertension and renal failure, but had less coronary disease, less previous cardiac surgery, and higher ejection fractions.

Rates of aortic dissection were similar between women and men, as were rates of hemiarch, total arch, and thoracoabdominal aortic repair. However, women underwent less aortic root reconstruction, including aortic root replacement, Ross, or valve-sparing root operations (29% vs 45%; P < .001).

Men had longer cross-clamp and cardiopulmonary bypass times than women, but similar durations of circulatory arrest, methods of cerebral perfusion, and nadir temperatures.

Women had a higher rate of death (11% vs 7.4%; P = .02), stroke (8.8% vs 5.5%; P = .01), and STS-COMP (31% vs 27%; P = .04). On multivariable analyses, female sex was an independent predictor of mortality (odds ratio [OR], 1.81; P < .001), stroke (OR, 1.90; P < .001), and STS-COMP (OR, 1.40; P < .001).

"We believe that these results should increase the awareness of aortic diseases in women for screening and diagnosis and, once a thoracic aortic aneurysm is found, aneurysm sizing must be indexed for the patient's size, especially in female patients. Earlier surgery may theoretically enable women to have operations earlier in the disease process, although this requires further research," Chu told theheart.org | Medscape Cardiology.

Chu said endovascular or hybrid therapies could have a role in narrowing the outcome gap between women and men undergoing aortic arch operations. In a recent study, the CTAC investigators showed that a novel hybrid arch frozen elephant trunk technique for aortic arch replacement appears to have similar outcomes between women and men, albeit in a limited sample size, he noted.

Concerning Findings

Reached for comment, Claire Boccia-Liang, MD, director of the women's heart program, Atlantic Health System's Morristown Medical Center, New Jersey, said the findings are "very concerning but not surprising."

As mentioned by the authors, women have higher mortality rates and adverse outcomes with cardiovascular surgery and tend to present later in the disease process and with more comorbidities, she noted.

"What is surprising," said Boccia-Liang, "is the odds ratio being so high for adverse outcomes for women versus men. I do think we need to be clinically mindful that women's' elevated operative mortality and stroke risk may, in part, be because we operate on women at an older age, with more comorbidities, and with aortas that are larger when indexed for size than men," she added.

"This study prompts us to garner more information through randomized clinical trials regarding the optimal time for operation on the ascending aorta for women," Boccia-Liang concluded.

The study had no specific funding. The authors and Boccia-Liang have no relevant disclosures.

Circulation. Published online February 13, 2019. Abstract


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