Yoneda, Masato

SummaryBackgroundProgression to cirrhosis in non‐alcoholic steatohepatitis (NASH) is associated with a decrease in liver fat. However, the prognostic significance of liver fat content in NASH‐related significant fibrosis and cirrhosis is unclear.AimTo investigate the risk of decompensation, hepatocellular carcinoma (HCC) and mortality stratified by liver fat content in NASH‐related significant fibrosis and cirrhosis.MethodsIn this meta‐analysis of individual participant data, 456 patients with both magnetic resonance elastography (MRE) and MRI‐derived protein density fat fraction (MRI‐PDFF) were enrolled, and 296 patients with longitudinal follow‐up were analysed. MRE combined with fibrosis‐4 (MEFIB‐index), and MRI‐PDFF were used to measure liver fibrosis and fat, respectively. MEFIB‐negative, MEFIB‐positive+ MRI‐PDFF ≥5% and MEFIB‐positive+ MRI‐PDFF <5% were defined as no significant liver fibrosis, NASH with significant fibrosis and higher liver fat content, and NASH with significant fibrosis and low liver fat content groups, respectively. The primary outcome was hepatic decompensation, HCC and death.ResultsThe rates of decompensation, HCC and mortality were highest in the NASH with significant fibrosis and low liver fat group (33%, 17% and 17%, respectively), followed by the NASH with significant fibrosis and higher liver fat group (18%, 13% and 13% respectively), and lowest in the no significant fibrosis (MEFIB‐negative) group (0%, 1% and 2% respectively). In multivariable‐adjusted analysis, low liver fat content was strongly associated (HR = 42.2 [95% CI: 7.5–235.5, p < 0.0001]) with HCC, decompensation and death. Sensitivity analyses for patients with cirrhosis (MRE ≥5 kPa) determined consistent findings.ConclusionsLow liver fat content in patients with burnt‐out NASH‐related significant fibrosis and cirrhosis is associated with an increase in hepatic decompensation, HCC and mortality.

Abstract Background and Aims Despite that hepatic fibrosis often affects the liver globally, spatial distribution can be heterogeneous. This study aimed to investigate the effect of liver stiffness (LS) heterogeneity on concordance between MR elastography (MRE)‐based fibrosis staging and biopsy staging in patients with NAFLD. Approach and Results We retrospectively evaluated data from 155 NAFLD patients who underwent liver biopsy and 3 Tesla MRE and undertook a retrospective validation study of 169 NAFLD patients at three hepatology centers. Heterogeneity of stiffness was assessed by measuring the range between minimum and maximum MRE‐based LS measurement (LSM). Variability of LSM was defined as the stiffness range divided by the maximum stiffness value. The cohort was divided into two groups (homogenous or heterogeneous), according to whether variability was below or above the average for the training cohort. Based on histopathology and receiver operating characteristic (ROC) analysis, optimum LSM thresholds were determined for MRE‐based fibrosis staging of stage 4 (4.43, kPa; AUROC, 0.89) and stage ≥3 (3.93, kPa; AUROC, 0.89). In total, 53 had LSM above the threshold for stage 4. Within this group, 30 had a biopsy stage of <4. In 86.7% of these discordant cases, variability of LSM was classified as heterogeneous. In MRE‐based LSM stage ≥3, 88.9% of discordant cases were classified as heterogeneous. Results of the validation cohort were similar to those of the training cohort. Conclusions Discordance between biopsy‐ and MRE‐based fibrosis staging is associated with heterogeneity in LSM, as depicted with MRE.