MRE plus FIB-4 (MEFIB) versus FAST in detection of candidates for pharmacological treatment of NASH-related fibrosis

BACKGROUND AND AIM Nonalcoholic fatty liver disease (NAFLD) patients with significant hepatic fibrosis (stage ≥ 2) are at increased risk of liver-related morbidity and are candidates for pharmacologic therapies. In this study, we compared the diagnostic accuracy of MEFIB (the combination of magnetic resonance elastography [MRE] and FIB-4) and FAST (FibroScan-AST; combined liver stiffness measurement by vibration-controlled transient elastography, controlled attenuation parameter, and aspartate aminotransferase) for detecting significant fibrosis. APPROACH AND RESULTS This prospective cohort study included 234 consecutive NAFLD patients who underwent liver biopsy, MRE, and FibroScan at University of California San Diego [UCSD] Cohort, and an independent cohort (N=314) from Yokohama City University, Japan Cohort. The primary outcome was diagnostic accuracy for significant fibrosis (stage ≥ 2). The proportion of significant fibrosis in UCSD and Yokohama cohorts were 29.5% and 66.2%, respectively. Area under the receiver operating characteristic curve (95% confidence interval) of MEFIB (0.860 [0.81-0.91]) was significantly higher than FAST (0.757 [0.69-0.82]) in UCSD cohort (p = 0.005), with consistent results in the Yokohama cohort (AUROC: 0.899 [MEFIB] vs 0.724 [FAST], p < 0.001). When used as the rule-in criteria (MEFIB: MRE ≥ 3.3 kPa and FIB-4 ≥ 1.6, and FAST ≥ 0.67), the positive predictive value for significant fibrosis was 91.2-96.0% for MEFIB, and 74.2-89.2% for FAST. When used as the rule-out criteria (MEFIB: MRE < 3.3 kPa and FIB-4 < 1.6, and FAST ≤ 0.35), negative predictive value for significant fibrosis was 85.6-92.8% for MEFIB, and 57.8-88.3% for FAST. CONCLUSIONS MEFIB has higher diagnostic accuracy than FAST for significant fibrosis in NAFLD, and our results support the utility of a two-step strategy for detecting significant fibrosis in NAFLD.