How often do we “miss” chronic hepatitis C patients with at least significant fibrosis by using Acoustic Radiation Force Impulse Elastography (ARFI) cut-off values proposed by meta-analysis?

Purpose: To evaluate how often we “miss” chronic hepatitis C patients with at least significant fibrosis (F≥2) that must be treated with specific antiviral therapy by using ARFI cut-off values proposed by meta-analysis.

Methods: Our study included 132 patients with chronic hepatitis C patients evaluated by means of ARFI and liver biopsy-LB (interpreted according to the METAVIR score). Ten liver stiffness (LS) measurements were performed in each patient. Reliable measurements were defined as: median value of 10 LS measurements with a success rate≥60% and an interquartile range interval< 30%, values expressed in meters/second (m/s). For predicting F≥2 we used the LS cut-off proposed in the published meta-analysis (1): 1.34 m/s.

Results: Reliable LS measurements by means of ARFI were obtained in 117 patients (87.9%). The classification of liver fibrosis in LB was: F0 – 5.9%, F1 – 9.4%, F2 – 44.5%, F3 – 28.2% and F4 – 11.9%. In our study, 58 patients (49.6%) had LS values < 1.34 m/s; from these 75.8% had F≥2 in LB. From the 59 patients (50.4%) with LS values≥1.34 m/s, only 6.8% had F0 or F1 in LB.

Conclusions: Similar with Transient Elastography, ARFI had a very good positive predictive value (93.2%) for predicting the presence of significant fibrosis, but the negative predictive value was low (24.2%). So, if the LS value obtained by means of ARFI elastography is at least 1.34 m/s, we can recommend directly antiviral therapy, but if the value is lower than 1.34 m/s a LB should be performed to recover those patients missed by the technique.

References: 1. Friedrich-Rust et al. J Viral Hepat.2012;19:e212 – 9