A Composite Indicator of Inflammation and Nutritional Status for Predicting Mortality After CABG: The CRP-to-Albumin...

Background: The C-reactive protein-to-albumin ratio (CAR) has emerged as a composite biomarker reflecting both systemic inflammation and nutritional status. This study investigated the prognostic value of preoperative and postoperative CAR in predicting early mortality following coronary artery bypass grafting (CABG). Methods: This retrospective study included 273 patients who underwent isolated CABG. Patients were categorized as mortality (+) (Ex group, n = 41) and mortality (-) (Non-Ex group, n = 232). Preoperative and postoperative CAR values were calculated and compared between groups. Independent predictors of mortality were evaluated using logistic regression analysis. Discriminative performance was assessed using receiver operating characteristic (ROC) curve analysis. Results: Early mortality occurred in 41 patients (15.0%). Both preoperative and postoperative CAR values were significantly higher in the mortality (+) group compared with the mortality (-) group. In multivariable logistic regression analysis, postoperative creatinine remained independently associated with early mortality, whereas neither preoperative nor postoperative CAR retained independent statistical significance after adjustment for clinical variables and renal function despite moderate discriminative performance in crude and ROC-based analyses. ROC analysis showed that CAR demonstrated moderate discriminative ability for mortality prediction, with postoperative CAR showing better performance than preoperative CAR. Conclusions: Although CAR demonstrated moderate discriminative performance for early mortality after CABG in unadjusted analyses, it did not independently predict mortality after adjustment for clinical variables and renal function. Therefore, CAR may be more appropriately interpreted as a supportive inflammation-based risk stratification marker rather than a stand-alone prognostic predictor.