Liver and Bile
J Hepatol. 2022;77(6):1545–53
Liver stiffness measurement by vibration-controlled transient elastography improves outcome prediction in primary biliary cholangitis
Background and aims: Liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) has been shown to predict outcomes of patients with primary biliary cholangitis (PBC) in small-size studies. The aim of this study was to validate the prognostic value of LSM in a large cohort study.
Methods: The authors performed an international, multicenter, retrospective follow-up study of 3985 patients with PBC seen at 23 centers in 12 countries. Eligibility criteria included at least 1 reliable LSM by VCTE and a follow-up ≥ 1 year. Independent derivation (n = 2740) and validation (n = 568) cohorts were built. The primary end point was time to poor clinical outcomes defined as liver-related complications, liver transplantation, or death. Hazard ratios (HRs) with 95%-confidence intervals (CIs) were determined using a time-dependent multivariable Cox regression analysis.
Results: LSM was independently associated with poor clinical outcomes in the derivation (5324 LSMs, mean follow-up 5.0 ± 3.1 years) and validation (1470 LSMs, mean follow-up 5.0 ± 2.8 years) cohorts: adjusted HRs (95% CI) per additional kPa were 1.040 (1.026–1.054) and 1.042 (1.029–1.056), respectively (p < 0.0001 for both). Adjusted C-statistics (95% CI) at baseline were 0.83 (0.79–0.87) and 0.92 (0.89–0.95), respectively. Between 5 and 30 kPa, the log-HR increased as a monotonic function of LSM. The predictive value of LSM was stable in time. LSM improved the prognostic ability of biochemical response criteria, fibrosis scores, and prognostic scores. The 8-kPa and 15-kPa cut-offs optimally separated low-, medium-, and high-risk groups. 40% of patients were at medium to high risk according to LSM.
Conclusions: Liver stiffness measurement by vibration-controlled transient elastography is a major, independent, validated predictor of primary biliary cholangitis (PBC) outcome. Its value as a surrogate end point for clinical benefit in PBC should be considered.