Clinical impact of visceral adiposity on long-term mortality in patients undergoing coronary artery bypass grafting.

Introduction and objectives: Although visceral adiposity increases cardiovascular risk in the general population, the obesity paradox has been reported in critically ill patients. However, evidence for its prognostic role in patients undergoing coronary artery bypass grafting (CABG) is limited. This study evaluated the prognostic implications of visceral adiposity in patients who underwent CABG using computed tomography-based measurement of visceral fat.

Methods: A total of 2810 patients who underwent CABG from 2007 to 2017 were analyzed. The study population was classified into 3 groups according to visceral fat area index (VFAI) tertiles. VFAI was calculated as visceral fat area (cm²)/height² (m²) at the L3 level. The primary outcome was all-cause mortality during follow-up.

Results: Patients in the low VFAI group (lowest tertile) were younger and had a lower body mass index and less subcutaneous fat than those in the high VFAI group (highest tertile). During a median 8.7-year follow-up, VFAI was significantly associated with the risk of mortality in restricted cubic spline curve analysis (HR, 0.94 per 10 increases; 95%CI, 0.91-0.97; P<.001). Patients in the low VFAI group had a higher incidence of long-term mortality than those in the intermediate and high VFAI groups (T1 36.1%, T2 27.2%, and T3 29.1%; T1 vs T2; adjusted HR, 1.36; 95%CI, 1.15-1.61; P<.001; T1 vs T3; adjusted HR, 1.37; 95%CI, 1.16-1.62; P<.001). Similar results were obtained after inverse probability treatment-weighting analysis.

Conclusions: Low visceral adiposity was associated with an increased risk of long-term mortality in patients who underwent CABG.