Assessing the prognostic impact of body composition phenotypes on surgical outcomes in patients with acute type A aortic dissection

Background: The prognostic significance of body composition phenotypes for patients undergoing emergency surgical intervention for acute type A aortic dissection (ATAAD) remains unclear. This study aimed to evaluate the impact of different body composition parameters on postoperative outcomes in ATAAD patients. Methods: A single-institution retrospective cohort study was conducted on patients who underwent emergency surgery for ATAAD between January 2016 and December 2021. Body composition analysis was performed using preoperative computed tomography (CT) scans, with skeletal muscle area, muscle quality, subcutaneous adipose tissue (SAT) area and visceral adipose tissue area (VAT) quantified at the third lumbar vertebra (L3) level. These parameters were analyzed for their association with early mortality, postoperative complications, and the durations of hospital and intensive care unit (ICU) stays. Results: Among 755 included patients (mean age 51.2±10.7 years; 84.4% male), sarcopenia and myosteatosis prevalence was 16.6% and 53.8%, respectively. Multivariable analyses identified myosteatosis as an independent predictor of prolonged overall hospital stay [β=3.02 days, 95% confidence interval (CI): 0.871-5.169; P=0.006] and ICU stay (β=1.835 days, 95% CI: 0.35-3.313; P=0.02). No statistically significant associations were observed for sarcopenia, SAT or VAT with any measured clinical outcomes. Conclusions: In ATAAD patients, body composition was not associated with early mortality or major complications, suggesting that emergency surgery should be considered across different phenotypes. Moreover, myosteatosis was independently associated with prolonged hospitalization and ICU stay, which may aid in postoperative risk stratification.