Background & Aims: Liver biopsy is invasive and associated with complications, sampling errors, and observer variability. Vibration-controlled transient elastography (VCTE) with FibroScan can be used to immediately assess liver stiffness. We aimed to define optimal levels of liver stiffness to identify patients with chronic viral hepatitis and significant fibrosis, advanced fibrosis, or cirrhosis. Methods: In a prospective, 2-phase study, patients with chronic hepatitis C or B underwent VCTE followed by liver biopsy analysis from January 2005 through May 2008 at 6 centers in the United States. In phase 1 we identified optimal levels of liver stiffness for identification of patients with stage F2-F4 or F4 fibrosis (the development phase, n= 188). In phase 2 we tested these cutoff values in a separate cohort of patients (the validation phase, n= 560). All biopsies were assessed for METAVIR stage by a single pathologist in the phase 1 analysis and by a different pathologist in the phase 2 analysis. Diagnostic performances of VCTE were assessed by area under the receiver operating characteristic curve (AUROC) analyses. Results: In phase 1 of the study, liver stiffness measurements identified patients with ≥F2 fibrosis with AUROC value of 0.89 (95% confidence interval, 0.83-0.92) and identified patients with F4 fibrosis with AUROC value of 0.92 (95% confidence interval, 0.87-0.95). Liver stiffness cutoff values (kPa) in phase 1 were 8.4 for ≥F2 (82% sensitivity, 79% specificity) and 12.8 for F4 (84% sensitivity, 86% specificity). In the phase 2 analysis, the liver stiffness cutoff values identified patients with ≥F2 fibrosis with 58% sensitivity (P < .0001 vs phase 1) and 75% specificity (nonsignificant difference vs phase 1); they identified patients with F4 fibrosis with 76% sensitivity (P < .0001 vs phase 1) and 85% specificity (nonsignificant differences vs phase 1). VCTE had an interobserver agreement correlation coefficient of 0.98 (n= 26) and an intraobserver agreement correlation coefficient of 0.95 (n= 34). Conclusions: In a large U.S. multicenter study, we confirmed that VCTE provides an accurate assessment of liver fibrosis in patients with chronic viral hepatitis. Our findings are similar to those from European and Asian cohorts.
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