Impact of Acute Liver Injury Prior to Left Ventricular Assist Device Therapy

Purpose The impact of pre-operative acute liver injury on post left ventricular assist device (LVAD) mortality is unknown. Methods The study cohort included adults with first time, continuous-flow LVAD implantation at a single center. Patients with complete laboratory data between -5 and -1 days prior to LVAD were included in the analysis. To assess for patients with acute liver injury pattern, AST and ALT were plotted, log transformed, and smoothed using the Locally Estimated Scatterplot Smoothing (LOESS) function. As AST and ALT tracked together, log AST alone was utilized for the remainder of the analysis. The association between peak and mean log AST prior to LVAD were assessed as predictors of post-LVAD mortality using multivariate cox regression. Results The study cohort consisted of 366 patients. The median age was 58 +/- 14 years old, 54.6% were bridge to transplant (BTT), and 53.3% had ischemic cardiomyopathy. The figure visually demonstrates the pattern of log AST prior to LVAD, stratified by patients who experienced death by 60 days post-implant. In the multivariate analysis, for each 1 unit increase in the peak log AST in the pre-LVAD time period, there was an adjusted 22% increase in post-LVAD mortality (HR 1.22, 95% CI 1.03 - 1.45, p=0.023). For each 1 unit increase in the mean log AST in the pre-LVAD time period, there was an adjusted 30% increase in post-LVAD mortality (HR 1.30, 95% CI 1.05 - 1.61, p=0.016). Models were adjusted for age, sex, BTT status, serum albumin, and ischemic cardiomyopathy. Conclusion Peak AST and higher mean AST levels prior to LVAD implantation were associated with increased post-LVAD mortality, despite improvement in liver injury pattern prior to LVAD. Ongoing organ dysfunction may be part of the mechanism of poor outcomes of patients who have experienced shock prior to LVAD placement.