Liver stiffness as a prognostic parameter and tool for risk stratification in advanced cardiac transthyretin amyloidosis

Background: In light of increasing therapeutic options, risk stratification of advanced cardiac transthyretin amyloidosis (ATTR-CA) is gaining clinical importance to avoid ineffective treatments. Liver stiffness as a marker of hypervolemia and hepatic congestion might predict mortality in advanced ATTR-CA and allow to identify patients at highest risk.
Methods: Proven ATTR-CA patients underwent repeated vibration-controlled transient elastography (VTCE) and standardized serial workup within the local amyloidosis cohort study AmyKoS. Spearman correlation analyses and Cox regressions were performed to evaluate the prognostic value.
Results: 41 patients with ATTR-CA were included with median age of 76.6 (55.1-89.1) years, of which 90.2% were male and > 92% wild-type ATTR-CA. In total, 85 VCTE examinations were performed. Median follow-up was 43.7 (2.4-75.6) months; 26.8% of the patients died. At the first clinical evaluation, median left ventricular (LV) absolute global longitudinal strain (GLS) was 11.4 (5.2-19.0) % and median liver stiffness was 6.3 (2.4-22.9) kPa, both significantly correlated with mortality. NT-proBNP possessed statistically significant predictive power in ATTR-CA with more preserved LV function (absolute GLS ≥ 10), whereas stiffness seemed to be more discriminative for ATTR-CA with absolute GLS < 10. The use of alternative congestion surrogates such as liver vein dilation and tricuspid regurgitation peak velocity (tr-vmax) showed congruent results.
Conclusion: Liver stiffness shows prognostic value regarding all-cause mortality and allows risk stratification in advanced ATTR-CA, particularly in those with markedly impaired longitudinal LV function. These results are transferable to other congestion surrogates.