A composite noninvasive index correlates with liver fibrosis scores in post-Fontan patients: Preliminary findings.

ABSTRACT

OBJECTIVE: We hypothesized that clinic-based, hepatic-ultrasound, elastography measurements, either alone or in combination with other noninvasive variables, might correlate with liver-biopsy fibrosis scores in patients post-Fontan. METHODS: Between March 2012 and February 2017, we identified patients post-Fontan that underwent elective cardiac catheterization and simultaneous transvenous hepatic biopsy. From this group, we selected patients that met inclusion criteria for liver-ultrasound, shear-wave elastography. Utilizing the results of elastography, laboratory testing, and time post-Fontan, we constructed a composite Fontan hepatic index as a sum of elastography measurements in kilopascals, model for end-stage liver disease excluding INR scores, and the square root of the number of years post-Fontan. Further, we analyzed correlations between Fontan hepatic index values and fibrosis scores from hepatic biopsy. RESULTS: We identified a total of 79 post-Fontan patients that underwent cardiac catheterization and liver biopsy. Of the 79 patients, 53 met inclusion criteria, and 32 consented to undergo hepatic-ultrasound elastography. Of the 32 that underwent elastography, data from 30 patients was used for analysis. We found no statistically significant differences in demographics, laboratory values, or cardiac catheterization data between the 30 included patients and the 21 that did not participate. Utilizing data from the 30 included patients, we found a strong, highly statistically significant correlation between the Fontan hepatic index values and total fibrosis scores (R = 0.8, P < .00001). However, the cohort size prevented reliable discriminating cut-off values for the range of total fibrosis scores. CONCLUSIONS: In a small cohort of patients post-Fontan, preliminary findings suggest that the composite Fontan hepatic index might be a clinically useful, noninvasive method of serially monitoring for hepatic fibrosis. Further studies, with large patient cohorts, are necessary to validate our findings and develop clinically useful discriminatory cutoff values.