P1850Usefulness and predictive value of the prognostic nutritional index compared to other commonly-used nutritional indexes as a prognostic nutritional marker for short- and mid-term survival after TAVR
Authors: Mas-Peiro S , Hoffmann J , Walther T , Zeiher A M , Fichtlscherer S , Vasa-Nicotera M 
Published: October 2019

Abstract

Background
Several nutritional indexes predict clinical outcomes after trans-catheter aortic valve replacement (TAVR). The Prognostic Nutritional Index (PNI) is based on serum albumin and lymphocyte count, which makes it a highly practical tool to assess nutritional status. Prognostic value of PNI has been shown in some heart diseases and interventions. Usefulness and predictive value of PNI were investigated in patients with symptomatic aortic stenosis undergoing TAVR. PNI was compared with other commonly-used nutritional indexes that predict survival after TAVR.

Methods
A prospective observational study was carried out in a cohort of 114 patients with aortic stenosis undergoing TAVR in a high-volume centre from 09/2016 to 02/2018. Pre-procedural characteristics and laboratory parameters were measured, and a 1-year follow-up was completed.
PNI was estimated with the formula: (10 × serum albumin [g/dl]) + (0.005 × total lymphocytes [1,000/μl]). Baseline clinical features and 1-year survival were compared in patients with PNI values above vs below median.
A multivariate Cox regression analysis was used to assess the independent predictive value of PNI, for 1-year mortality after TAVR. Kaplan-Meier curves were constructed for patients with PNI above vs below median value. ROC curves were created to assess discrimination ability of PNI, and to compare its AUC values with those for other common nutritional markers, such as Geriatric Nutritional Risk Index (GNRI) and body mass index (BMI).

Results
Mean age was 82.2 years and 59.6% of patients were female. Mean PNI was 46±5. No differences were found in pre-procedural clinical characteristics between patients with PNI values above vs below median.
One-year mortality was significantly higher in patients with PNI values below median (19/23) than in patients with higher PNI values (4/23) (p<0.001). No differences were found in complications according to Valve Academic Research Consortium Criteria-2.
Lower PNI values significantly predicted a lower 1-year survival, even after adjusting for all clinical factors showing significant differences in a univariate analysis (model 1: HR 0.8, 95% CI 0.7–0.9, p<0.0001). Significance persisted also after adjusting for relevant laboratory factors (NT-proBNP, hs-Troponin, CRP, eGFR, cystatin, haemoglobin) (model 2: HR 0.8, 95% CI 0.7–0.9, p<0.05). Kaplan-Meier curves started to diverge soon after the intervention (figure). ROC curves revealed a stronger predictive value for PNI (AUC 0.80) compared to GNRI (0.77) and BMI (0.6) (figure).
Kaplan-Meier curve for PNI and ROC curve

Conclusion
PNI is a useful and practical nutritional marker predicting 1-year survival after TAVR in aortic stenosis. It appears to reflect malnutrition and inflammation prior to the intervention, and to have an impact on prognosis. PNI seems to be a better prognostic marker than BMI or GNRI after TAVR.