Prediction of long-term morbidity and mortality after liver transplantation using two-dimensional shear wave elastography compared with liver biopsy

Abstract

The role of noninvasive liver disease assessment by two-dimensional shear wave elastography (2D-SWE) to diagnose fibrosis is well described in patients with chronic liver disease. However, its role in prognosis, especially after liver transplantation (LT) has not been adequately examined. We hypothesized that elevated liver stiffness measurement (LSM) as measured by 2D-SWE after LT predicts future morbidity and mortality independent of fibrosis by liver biopsy. In a prospective cohort study, consecutive LT recipients underwent concomitant protocol 2D-SWE and protocol liver biopsy (2012-2014), with the assessor blinded to biopsy findings. We examined the baseline correlation of LSM with fibrosis stage and the association between elevated LSM and the development of subsequent clinical outcomes and all-cause mortality. A total of 187 LT recipients (median age 58 years, 38.5% women, median body mass index 26.5 kg/m² , 55.1% hepatitis C virus, 17.6% nonalcoholic steatohepatitis/cryptogenic) were examined. Median time between LT and biopsy/2D-SWE assessment was 4.0 years, and the median follow-up time after LSM determination was 3.5 years. Median LSM was 9 kPa (8 kPa [F0/F1], 11.5 kPa [F2], 12 kPa [F3/F4]). There was a positive correlation between LSM and fibrosis stage (r_s = 0.41; p < 0.001). LSM ≥11 kPa was associated with lower survival within 3 years (84.8 vs. 93.7%; p = 0.04). After adjusting for age, sex, and fibrosis stage, LSM ≥11 kPa was independently associated with mortality (hazard ratio, 2.45; 95% confidence interval, 1.08-5.60). Elevated LSM by 2D-SWE is associated with increased mortality after LT independent of hepatic fibrosis. Given the overall decrease in the use of liver biopsy in the current era, 2D-SWE may serve as a novel noninvasive prognostic tool to predict relevant outcomes late after LT.