Value of prognostic nutritional index for survival prediction in trans-catheter aortic valve replacement compared to other common nutritional indexes

Abstract

Background Nutritional status predicts outcomes after TAVR. Predictive value of Prognostic Nutritional Index (PNI) was investigated in patients undergoing TAVR, and compared to other nutritional indexes. Methods A cohort of 114 patients undergoing TAVR in a high-volume centre was studied. A prospective 1-year follow-up was completed. PNI was estimated as follows: (10 × serum albumin[g/dl])+(0.005 × total lymphocytes [1000/μl]). One-year survival was compared in patients with PNI above vs below median; Kaplan–Meier curves were created. A multivariate analysis was used to assess predictive value of PNI for 1-year mortality. ROC curves were used to assess discrimination by PNI, and to compare it with Geriatric Nutritional Risk Index (GNRI) and Body Mass Index (BMI). Results Mean age was 82.2 years, 59.6% were male. Mean PNI was 46 ± 5. Pre-procedurally, no differences were found between patients with high vs. low PNI. One-year mortality was significantly higher in patients with low PNI values (19/57 vs. 4/57; p < .001). Complications did not differ. A higher PNI predicted 1-year survival, even after adjusting for clinical factors (model 1: HR 0.8, 95% CI 0.7–0.9, p < .0001) and laboratory parameters (NT-proBNP, IL-6, CRP, eGFR, cystatin C, haemoglobin) (model 2: HR 0.8, 95% CI 0.7–0.9, p < .05). ROC curves revealed a stronger predictive value for PNI (AUC 0.80) compared to GNRI (0.77) and BMI (0.6). The optimal cut-off for PNI was 45. Conclusion PNI is a useful and practical nutritional marker reflecting malnutrition and inflammation prior to the intervention, and strongly predicts 1-year survival. PNI seems to be a better prognostic marker than BMI or GNRI after TAVR.