Noninvasive predictors of clinically significant portal hypertension in NASH cirrhosis: Validation of ANTICIPATE models and development of a lab-based model

Abstract

Clinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥ 10 mm Hg, identifies patients with compensated cirrhosis at a high risk of decompensation. However, HVPG is an invasive and nuanced method. The ANTICIPATE models, which include liver stiffness measurements by transient elastography (TE) and platelet count ± body mass index, are robust noninvasive surrogates of CSPH but required external validation in patients with nonalcoholic steatohepatitis (NASH) cirrhosis. Additionally, TE is not widely available worldwide. The aims of the study were: (1) to externally validate the ANTICIPATE models using baseline data from patients with compensated NASH cirrhosis screened/enrolled in a multicenter international randomized controlled trial; and (2) to develop and externally validate a model using only laboratory values. Regarding aim 1, both ANTICIPATE models showed good calibration and discrimination (area under the curve [AUC] > 0.8) in our cohort (n = 222). Regarding aim 2, a new lab-based model using the Fibrosis-4 index (FIB-4 [age, aspartate aminotransferase, alanine aminotransferase, platelet count]) plus serum albumin was developed. The discrimination in the training cohort (n = 309) was good (AUC of 0.78 [95% confidence interval [CI]:0.72–0.83]). It was then externally validated in a separate cohort of 245 patients with compensated NASH cirrhosis (AUC of 0.8 [95% CI: 0.75–0.86]). Given the difference in the prevalence of CSPH between training (74%) and validation (39%) cohorts, the model required an update of the baseline risk to achieve a good calibration. The updated model was named FIB4+. In conclusion, both ANTICIPATE models performed well in predicting the presence of CSPH in NASH cirrhosis. A model using FIB-4 plus albumin (FIB4+) can be used to predict CSPH where TE is not available.