Low ALT Levels Do Not Predict Mortality After Liver Transplantation

Abstract

Introduction: Recent studies suggest low alanine aminotransferase (ALT) levels are associated with increased mortality, especially in elderly patients over the age of 70, as well as patients with coronary artery disease and patients requiring hemodialysis. Prior studies have postulated that low ALT levels are associated with increased frailty, a difficult parameter to objectively quantify, resulting in the associated increased mortality. To our knowledge, there has not been prior inquiry into low ALT in patients with chronic liver disease undergoing orthotopic liver transplantation (OLT). The aim of our current study was to determine if low ALT levels prior to OLT are associated with higher post-transplant morbidity/mortality, and could be used as a marker of frailty in pre-transplant patient selection. Methods: A retrospective chart review was performed of 485 consecutive liver transplants from January 2012 to December 2017 at the University of Cincinnati Medical Center. Based on prior studies, low ALT was defined as 15 U/L in women and 17 U/L in men. Baseline clinical characteristics and laboratory parameters by ALT groups were compared. Logistic regression modeling was carried out to evaluate baseline factors independently associated with all-cause mortality. Differences in survival between subjects according to ALT were assessed using the Kaplan-Meier method. Results: Of the 485 cases, 149 (39%) had low ALT prior to OLT. There were 37 simultaneous liver-kidney transplants included in the cohort, 8 of which had low ALT (5%). Patients with low ALT were older compared to the patients without low ALT (57.4 vs 55.4, p=0.05), but otherwise the groups were similar amongst baseline characteristics tested. After a median follow-up of 32.5 months, there were 72 deaths after OLT in the cohort, 25 with low ALT (14%) compared to 47 (16.7%) without low ALT (p=0.452). The secondary outcomes of 30 day and 1-year readmission were not significantly different between the two groups. The median overall survival with low ALT was 4.92 months (CI 2.13-14.7) compared to 8.46 months without low ALT (CI 2.07-16.3), however this difference was not statistically significant. Conclusion: Low ALT prior to orthotopic liver transplantation did not predict increased mortality or other complications such as readmissions in our study population.979_A Figure 1. Kaplan-Meier curve of mortality based on ALT levels979_B Figure 2. Kaplan-Meier curve of overall mortality after OLT