Women face higher mortality following TEVAR for intact descending thoracic aortic aneurysms

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Marc Schermerhorn

Even after adjusting for differences in age and comorbidities, female patients have higher perioperative mortality and lower long-term survival after thoracic endovascular aneurysm repair (TEVAR), according to a study published by the Journal of Vascular Surgery.

Although differences between males and females in pathogenesis, presentation, and outcomes of repair for abdominal aortic aneurysms are well studied, less is known about the differences following TEVAR. Previous studies assessing sex differences after TEVAR have suggested no difference in mortality, although their impact has been limited by small sample sizes.

Attempting to fill this gap in the literature, Marc Schermerhorn (Beth Israel Deaconess Medical Center, Boston, USA) and colleagues conducted a retrospective review of all TEVARs in the Society for Vascular Surgery Vascular Quality Initiative (VQI) registry from 2011 to 2015.

Statistical analysis was performed using the Fisher exact test and the Mann-Whitney U test for categorical and continuous variables. Multivariable logistic regression and Cox hazards modelling were used to account for differences in demographics, comorbidities, and aneurysm characteristics in 30-day mortality and long-term survival.

Excluding patients with dissection, trauma, and rupture, the team identified 2,574 patients (40% of which were women) who underwent TEVAR. Women were generally older, were less likely to be white, and had smaller aortic diameters but larger aortic size indices (aortic diameter/body surface area). Women also had more chronic obstructive pulmonary disease but less coronary artery disease and fewer coronary interventions.

Schermerhorn and colleagues also reported that women were more likely to be symptomatic at presentation and subsequently to have a non-elective procedure. Women had higher estimated blood loss >500mL (20% vs. 17%; p=0.04), were more likely to be transfused (29% vs. 21%; p<0.001), and more frequently underwent iliac access procedures (4.3% vs. 2.1%; p<0.01).

Operative time and left subclavian intervention were similar between the female and male groups. Postoperatively, women had increased median hospital (5 vs. 4 days; p<0.001) and intensive care unit (2.5 vs. 2 days; p<0.001) lengths of stay and were less likely to be discharged home (75% vs. 86%; p<0.001). Mortality was higher for women at 30 days (5.4% vs. 3.3%; p<0.01) and one year (9.8% vs. 6.3%; p<0.01). After adjusting for age, aortic size index, symptoms, and comorbidities, female sex remained independently predictive of 30-day mortality (odds ratio, 1.5; 95% confidence interval, 1.1–2.1, p<0.01) and long-term mortality (hazard ratio, 1.3; 95% confidence interval, 1.03–1.6; p=0.02).

“We found that female patients have higher 30-day and long-term mortality compared with male patients after TEVAR for intact descending thoracic aortic aneurysms,” Schermerhorn et al write. “The reason for this is likely to be multifactorial, but possible explanations include more complicated aortic or access vessel anatomy, higher rates of symptomatic aneurysms, worse baseline health, and other social impacts on health status.”

“These findings, along with the rupture risk by sex, should be considered by clinicians in determining the timing of intervention,” Schermerhorn and colleagues explain. They continue, “The decision to repair an aortic aneurysm weighs the rupture risk, life expectancy, and morbidity and mortality risk associated with operative repair. Therefore, if female patients experience higher perioperative mortality, this should factor into the operative decision-making.”

“Different aneurysm size thresholds by sex have been suggested in abdominal aortic aneurysms, given the higher rupture risk at smaller diameters in female patients. In addition, female patients in our study also had higher rates of chronic obstructive pulmonary disease, which is also known to correlate with rupture risk. We have no data from this study regarding risk of rupture, but the operative mortality in female patients remained higher even after adjusting for aortic diameter and aortic size index. Further research is needed to determine the ideal threshold for repair, by either diameter or aortic size index, weighing the reduced life expectancy and increased operative burden with the potential rupture risk.”