Performance of the comprehensive nutrition screening index in predicting mortality after cardiac surgery

Malnutrition is a significant risk factor for postoperative outcomes in patients undergoing cardiac surgery. The Seoul National University Hospital-Nutrition Screening Index (SNUH-NSI) is an automated screening tool designed to comprehensively assess malnutrition risk. However, its predictive value in patients undergoing cardiac surgery remains unvalidated. This study included adult patients who underwent cardiac surgery at a tertiary teaching hospital between May 2008 and December 2019. Patients were classified as low-, intermediate-, or high-risk for malnutrition based on the SNUH-NSI. The association between malnutrition risk and postoperative cumulative all-cause mortality was evaluated using multivariable Cox regression analysis. The predictive ability of the SNUH-NSI was compared with conventional nutritional indices. Compared to the low-risk group, both the high-risk (adjusted hazard ratio [HR], 2.64; 95% confidence interval [CI], 2.19-3.19; P < 0.001) and intermediate-risk groups (adjusted HR, 1.54; 95% CI, 1.31-1.82; P < 0.001) demonstrated a significantly elevated risk of cumulative all-cause mortality. The multivariable model incorporating SNUH-NSI demonstrated moderate but superior predictive performance compared to that of other conventional nutritional indices. Preoperative malnutrition assessed by the SNUH-NSI was found to be a significant predictor of mortality following cardiac surgery. Implementing the SNUH-NSI for automated preoperative malnutrition screening could be an efficient and cost-effective approach.