Challenging BMI: Fat Mass Indices for Improved Postoperative Risk Prediction in CABG Patients.

Area of Science:

• Cardiology
• Surgical Outcomes
• Body Composition Analysis

Background:

• Coronary artery bypass grafting (CABG) patients face significant postoperative morbidity and mortality risks.
• Preoperative body composition, specifically fat mass and fat-free mass indices and ratios, may influence surgical outcomes.
• Understanding these factors can improve patient risk stratification and management.

Purpose of the Study:

• To investigate the impact of preoperative fat mass index (FMI), fat-free mass index (FFMI), fat mass ratio (FMR), and fat-free mass ratio (FFMR) on postoperative morbidity in CABG patients.
• To identify predictive thresholds for key body composition metrics related to specific complications like wound dehiscence.

Main Methods:

• Prospective study including 120 CABG patients.
• Preoperative evaluation of FMI, FFMI, FMR, and FFMR.
• Receiver operating characteristic (ROC) curve analysis to determine threshold values for FMR, FFMR, and FMI.
• Multivariate logistic regression to identify independent risk factors for infection site leakage.

Main Results:

• ROC analysis identified threshold values: FMR 0.26, FFMR 0.73, FMI 7.46.
• Elevated FMI, FMR, and FFMR were associated with BMI, diabetes, and wound dehiscence (AUC=0.600).
• Specific thresholds (FMR > 0.26, FFMI < 0.73) indicated increased risk for pulmonary embolism.
• Patients with optimal FFMI ranges showed significantly less postoperative atrial fibrillation and wound dehiscence.
• FMR > 0.26 and FMI > 7.46 significantly increased wound dehiscence risk (3-38 fold), independent of BMI.
• No significant association found between fat mass measurements and mortality.

Conclusions:

• Preoperative fat mass measurements are effective predictors of postoperative morbidity in CABG patients.
• These measurements offer valuable risk prediction, especially for non-obese individuals.
• Body composition analysis can enhance preoperative risk assessment and guide clinical management strategies.