A Stepwise Algorithmic Approach and External Validation Study for Noninvasive Prediction of Advanced Fibrosis in Nonalcoholic Fatty Liver Disease.

BACKGROUND AND AIMS: Advanced F3-4 fibrosis predicts liver-related mortality in nonalcoholic fatty liver disease (NAFLD). Noninvasive tests, designed to rule in/out advanced fibrosis, are limited by indeterminates, necessitating biopsy. We aimed to determine whether stepwise combinations of noninvasive serum-based tests and elastography (VCTE) could predict F3-4, reduce indeterminates, and decrease liver biopsies. METHODS AND RESULTS: Five hundred forty-one biopsy-proven NAFLD cases were identified between 2010 and 2018 from two Canadian centers. Characteristics of training (n = 407)/validation (n = 134) cohorts included: males 54%/59%; mean age 48.5/52.5 years; mean body mass index 32.3/33.6 kg/m2; diabetes mellitus 30%/34%; and F3-4 48%/43%. For training/validation cohorts, area under the receiver operating curve (AUROC) for FIB-4, AST-platelet ratio index (APRI), NAFLD fibrosis score (NFS), BARD score, and AST/ALT ratio ranged from 0.70 to 0.83/0.68 to 0.81, with indeterminates 25-39%/34-45%, for F3-4. In the training cohort, parallel FIB-4 + NFS had good accuracy (AUROC = 0.81) but was limited by 38% indeterminates and 16% misclassified. Sequential FIB-4 → NFS reduced indeterminates to 10%, and FIB-4 → VCTE to 0%, misclassified 20-22%, while maintaining high specificity (0.88-0.92) and accuracy (AUROC 0.75-0.78) for combined cohorts. Liver biopsy could have been avoided in 27-29% of patients using sequential algorithms. CONCLUSIONS: Sequential FIB-4 âž” NFS/VCTE predicts F3-4 with high specificity and good accuracy, while reducing indeterminates and need for biopsy. Parallel algorithms are limited by high indeterminates. Sequential FIB-4 âž” NFS had similar accuracy to VCTE-containing algorithms. Validation in low-prevalence cohorts may allow for potential use in community or resource-limited areas for risk stratification.

Monitoring Occurrence of Liver-Related Events and Survival by Transient Elastography in Patients With Nonalcoholic Fatty Liver Disease and Compensated Advanced Chronic Liver Disease.

BACKGROUND & AIMS: Patients with advanced fibrosis related to nonalcoholic fatty liver disease (NAFLD) are at risk of developing hepatic and extrahepatic complications. We investigated whether, in a large cohort of patients with NAFLD and compensated advanced chronic liver disease, baseline liver stiffness measurements (LSMs) and their changes can be used to identify patients at risk for liver-related and extrahepatic events. METHODS: We performed a retrospective analysis of consecutive patients with NAFLD (n = 1039) with a histologic diagnosis of F3-F4 fibrosis and/or LSMs>10 kPa, followed for at least 6 months, from medical centers in 6 countries. LSMs were made by FibroScan using the M or XL probe and recorded at baseline and within 1 year from the last follow-up examination. Differences between follow up and baseline LSMs were categorized as: improvement (reduction of more than 20%), stable (reduction of 20% to an increase of 20%), impairment (an increase of 20% or more). We recorded hepatic events (such as liver decompensation, ascites, encephalopathy, variceal bleeding, jaundice, or hepatocellular carcinoma [HCC]) and overall and liver-related mortality during a median follow-up time of 35 months (interquartile range, 19-63 months). RESULTS: Based on Cox regression analysis, baseline LSM was independently associated with occurrence of hepatic decompensation (hazard ratio [HR], 1.03; 95% CI, 1.02-1.04; P < .001), HCC (HR, 1.03; 95% CI, 1.00-1.04; P = .003), and liver-related death (HR, 1.02; 95% CI, 1.02-1.03; P = .005). In 533 patients with available LSMs during the follow-up period, change in LSM was independently associated with hepatic decompensation (HR, 1.56; 95% CI, 1.05-2.51; P = .04), HCC (HR, 1.72; 95% CI, 1.01-3.02; P = .04), overall mortality (HR, 1.73; 95% CI, 1.11-2.69; P = .01), and liver-related mortality (HR, 1.96; 95% CI, 1.10-3.38; P = .02). CONCLUSIONS: In patients with NAFLD and compensated advanced chronic liver disease, baseline LSM and change in LSM are associated with risk of liver-related events and mortality.