Model for End-Stage Liver Disease Excluding INR (MELD-XI) Score Predicts Outcomes in Pediatric Patients Supported with Ventricular Assist Device: An Analysis of the PediMACS Registry

Abstract

Our study aims to identify the utility of pre-implant MELD-XI score in identifying pediatric patients at higher risk for morbidity and mortality post-VAD implant. We reviewed all patients listed in the PediMACS database from 9/19/12 to 3/31/19. Patients missing bilirubin or creatinine that precluded calculation of MELD-XI score (n=89) were excluded. Patients were divided into three cohorts based on MELD-XI score pre-implant - low (minimum score 9.4, < 25%-tile), intermediate (scores 9.4-13.6, 25-75%-tile), and high (scores >13.6, 75-100%-tile). Baseline clinical and hemodynamic data were compared; outcomes data on morbidity and mortality were compared across groups. Of 596 patients included, 42.5% were in the low, 29.2% in the intermediate and 28.3% in the high MELD-XI cohort. Compared to the low and intermediate cohorts, patients in the high MELD-XI cohort were significantly older (p<0.01); more likely had congenital heart disease (17.8 vs. 24.7 vs. 30.2%, p<0.01); elevated NT-pro BNP, elevated AST and ALT (p<0.05). They were more likely to be mechanically ventilated, on ECMO and INTERMACS 1 (p<0.01) pre-implant. Compared to the low-MELD-XI cohort, patients in the high MELD-XI cohort had an increased risk of death [14.7 vs. 29.5%, p<0.01] (Figure) and a lower probability of transplant [69.4 vs. 50.1, p<0.01] at 12 months post-VAD implant. On multivariable analysis, a high MELD-XI score persisted as highly significant risk factor for early mortality (HR 1.7, p<0.01) (Table). Pediatric patients with an elevated MELD-XI score have higher acuity of illness pre-implant. This easily calculated score based on routinely collected lab values serves as a promising risk assessment tool in identifying pediatric VAD recipients at increased risk for mortality post VAD implant. Trending the MELD-XI score in patients with advanced heart failure may aid clinicians in timing of VAD implantation.