Risk analysis using the prognostic nutritional index in hemodialysis-dependent patients undergoing cardiac surgery

The prognostic nutritional index is an effective prognostic tool used in gastrointestinal surgeries. However, its value has not been verified in cardiovascular surgeries. This study aimed to investigate its utility in hemodialysis-dependent patients undergoing cardiac surgery. We retrospectively reviewed data of 110 hemodialysis-dependent patients who underwent cardiac surgery between January 2006 and July 2016. 20 variables were evaluated for short- and long-term mortality prediction. Patients were divided into high and low prognostic nutritional index groups with values > 34 (n = 90) and ≤ 34 (n = 20), respectively. Preoperative characteristics and surgical outcomes were compared between both groups. Overall, the in-hospital mortality rate was 9% (n = 10) and the 1-, 3-, and 5-year actual survival rates were 69%, 58%, and 40%, respectively. Univariate analysis for hospital death revealed age ≥ 70 years, body mass index ≤ 18 kg/m², total cholesterol ≤ 120 mg/dl, concomitant procedures, albumin concentration ≤ 3.0 g/dl, and prognostic nutritional index ≤ 34 as risk factors. Multivariate logistic regression analysis confirmed age ≥ 70 years and concomitant procedures as independent risk factors. Whereas ejection fraction ≤ 30% and prognostic nutritional index ≤ 34 were strong independent predictors of long-term death. Patients in the low prognostic nutritional index group had significantly longer postoperative hospitalization, higher incidence of complications, significantly higher in-hospital mortality rate, and significantly lower actual survival rate. The low prognostic nutritional index affected surgical outcomes in hemodialysis-dependent patients undergoing cardiac surgery. Perioperative nutrition management based on the prognostic nutritional index may improve surgical outcomes.