Impact of body fat quality on long-term survival following endovascular repair for abdominal aortic aneurysms

<h2>ABSTRACT</h2><h3>Objective</h3> To evaluate the impact of body fat quality and quantity on long-term survival following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs). <h3>Methods</h3> A single-center, retrospective cohort study was performed on 237 patients who underwent primary EVAR for AAA from 2016 to 2019. Fat quality was assessed by measuring the Hounsfield units (HUs) of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) at the level of third lumbar vertebra on preoperative non-contrast computed tomography (CT). Fat quantity was assessed by measuring the area (cm²) of SAT and VAT at the level of the umbilicus. Hazard ratios (HRs) for all-cause mortality were calculated for each variable using univariate and multivariate analysis. <h3>Results</h3> This study included 237 patients with a mean age of 76.8 years, of whom 33 were female. The median body mass index (BMI, kg/m²) was 23.4 (interquartile range [IQR], 21.6-26.0), and 226 patients (95.3%) were classified as non-obese. During the median follow-up period of 72 months, there were 107 all-cause deaths. In univariate analysis, overall survival was significantly lower in patients with higher SAT or VAT density or larger SAT or VAT area among body fat-related parameters. In a multivariate analysis, SAT density was an independent risk factor for all-cause mortality following EVAR (SAT density: HR, 1.02, 95% confidence interval [CI], 1.01-1.03; <i>P</i> = 0.007), along with other variables including age, sarcopenia, osteoporosis, and aneurysm diameter. <h3>Conclusions</h3> Patients with higher SAT density showed increased all-cause mortality following EVAR. This finding suggests that fat quality, rather than fat quantity, may be more closely associated with long-term survival in post-EVAR patients.