Background: Transient elastography (TE) is a noninvasive tool to assess hepatic fibrosis by measuring liver stiffness (LS). Recent studies suggest that TE may be used to screen for liver cirrhosis and clinically significant portal hypertension (≥ 10 mmHg; CSPH), whereas data on the clinical applicability of TE are limited.
Methods: Among 695 patients undergoing measurement of LS, data on liver biopsies and on hepatic venous pressure gradient (HVPG) were available in 290 and 502 patients, respectively. Analysis of the area under the receiver operating curve (AUC) was used to assess the positive (PPV) and negative predictive (NPV) values of LS cut-offs for staging of hepatic fibrosis and for diagnosis of CSPH.
Results: LS was significantly associated with fibrosis stage (R = 0.872;p < 0.0001). AUC for diagnosis of fibrosis F2 (> 7.2 kPa) was 0.690, 0.737 for F3 (> 9.6 kPa), and 0.904 for F4 (> 12.1 kPa), respectively. At a LS cut-off of 12.1 kPa the PPV and NPV for diagnosis of cirrhosis were 87 and 91 %, respectively. A significant correlation of LS and HVPG was noted (R = 0.794;p < 0.0001), being stronger in patients with viral disease (R = 0.838;p < 0.0001) than in patients with alcoholic disease (R = 0.756;p < 0.0001). The LS cut-off at 18 kPa can identify CSPH with a PPV and NPV of 86 and 80 %, respectively.
Conclusions: This large single center study confirms the clinical utility of TE as valuable noninvasive screening tool for liver fibrosis with excellent accuracy to rule out F4 cirrhosis. However, the moderate PPV and NPV limit the diagnostic use of TE for discriminating patients with and without CSPH.