Association of Body Mass Index with Outcomes After Thoracic Endovascular Aortic Repair in The Vascular Quality Initiative.

OBJECTIVE: While several studies have evaluated the impact of obesity on outcomes following abdominal aortic aneurysm repair, literature examining this association in thoracic endovascular aortic repair (TEVAR) is sparse. Here, we use a multi-institutional, international database to assess the role of body mass index (BMI) on adverse outcomes in patients undergoing TEVAR for descending thoracic aortic aneurysms (DTAA) and type B dissections (TBD).

METHODS: A retrospective review of all patients undergoing TEVAR for DTAA or TBD from August 2014 to August 2020 was performed. Patients who were underweight (BMI<18.5Kg/m2 ) or obese (BMI≥30Kg/m2 ) were compared to those of normal weight (≥18.5-<30Kg/m2 ). Adjustment for confounding was done with multivariable logistic regression or Cox proportional hazards regression as appropriate for studying postoperative or long-term outcomes. Primary outcomes were 30-day and 1-year mortality. Other outcomes included any postoperative complication, stroke, and spinal cord ischemia.

RESULTS: A total of 3,423 participants were included in the study, of which 3.3% (n=113) were underweight, 65.9% (n=2,253) had normal weight and 30.8% (n=1,053) were obese. Compared to normal weight, there was no significant difference in 30-day mortality in underweight patients (OR, 1.81; 95%CI, 0.80-4.14; P=0.156). Obese patients undergoing TEVAR for TBD had a 2.7-fold increase in the odds of 30-day mortality compared to normal weight (OR, 2.67, 95%CI, 1.52-4.68; P=0.001). Obese and normal weight patients with DTAA had equivalent odds of 30-day mortality (OR, 1.32; 95%CI, 0.79-2.23, P=0.292). The adjusted hazard of 1-year mortality was 2-fold higher in underweight patients compared to normal weight (HR, 2.15, 95%CI, 1.41-3.29, P<0.001), driven by a higher risk of mortality among patients with thoracic aortic aneurysm (OR, 2.62; 95%CI, 1.63-4.21; P<0.001). There was no significant difference in 1-year mortality risk between normal weight and obesity in both DTAA (OR, 0.77; 95%, 0.54-1.09; P=0.146) and TBD (OR, 1.26; 95%CI, 0.85-1.86; P=0.248).

CONCLUSIONS: In this study, obese patients undergoing TEVAR for DTAA had comparable 30-day and 1-year mortality risk as normal weight individuals. Obese patients undergoing TEVAR for TBD demonstrated 2.7-fold increase in the odds of 30-day mortality, but equivalent mortality risk as normal weight patients at 1 year. TEVAR represents a safe minimally invasive option for treatment of DTAA in obese patients. Future work should be directed towards minimizing perioperative mortality among patients with TBD in order to optimize TEVAR outcomes.