Preoperative Nutritional Assessment with the Prognostic Nutrition Index in Patients Undergoing Left Ventricular Assist Device Implantation.

Abstract

The prognostic nutritional index (PNI) is a simple metric that uses serum albumin and total lymphocyte count to provide a basic indicator for nutritional status. It has recently garnered attention as a prognosticator of outcomes in many types of cancer. We investigated the utility of the PNI as a marker for poor outcomes following left ventricular assist device (LVAD) implantation. Two hundred eighty-eight consecutive patients implanted with continuous-flow LVADs were included. Prognostic nutritional index was calculated for all patients (PNI = [10 × serum albumin {g/dl}] + [0.005 × total lymphocytes {1,000/μl}]). The population was split into two groups based on median PNI; group 1 with PNI <30 and group 2 with PNI ≥30. Mean age was 60.3 years in group 1 and 59.8 years in group 2. There were no significant differences between groups in terms of age, gender, ethnicity, or comorbidities. The mean PNI for the group as a whole was 30.1 ± 4.6, indicating pervasive malnutrition in this group of advanced heart failure patients. Group 1 had significantly longer postoperative length of stay than did group 2 (27.42 ± 19.31 vs. 21.66 ± 15.0 days; p = 0.008). Patients in group 1 also had higher rates of right ventricular failure (37.8% vs. 25.5%; p = 0.025). A multivariate model indicated that PNI less than 30 was associated with a 12.2% reduction in postoperative survival (Hazard Ratio: 0.888; confidence interval [CI]: 0.795-0.993; p = 0.037). Our results suggest that the PNI may be an indicator for worsened outcomes in patients with advanced heart failure. These patients, who often suffer from chronic malnutrition, may experience worsened outcomes because of associated neurohormonal, muscular, and metabolic derangements.