The Utility of Follow-up Transthoracic Echocardiogram to Screen for Severe Portopulmonary Hypertension (POPH) in Patients Granted POPH Model for End-stage Liver Disease (MELD) Exceptions

Background. The current model for end-stage liver disease (MELD) exception policies for portopulmonary hypertension (POPH) require serial right heart catheterizations (RHCs) every 3 mo to maintain exception points. RHC is necessary for the initial diagnosis of POPH, but the utility of serial catheterizations has not been studied. In patients with POPH MELD exceptions, we sought to compare noninvasive and invasive hemodynamics and determine the sensitivity of echocardiography for the detection of hemodynamically severe POPH that would preclude liver transplant. Methods. We performed a single-center retrospective cohort study of patients with POPH MELD exceptions who underwent liver transplant from December 2008 to January 2024. Results were validated at an external center. Echocardiograms and RHCs performed within 1 mo were compared. Pearson correlation coefficient and Bland-Altman plots assessed the association between echocardiogram and RHC variables. We examined varied echocardiographic parameters to optimize sensitivity for the detection of hemodynamically severe POPH. Results. Twenty-two individuals underwent 60 follow-up RHCs with paired echocardiograms. Right ventricular systolic pressure (RVSP) and cardiac index estimated with echocardiogram were not strongly correlated with RHC measurements at follow-up (RVSP and RHC pulmonary artery systolic pressure: R = 0.30, P = 0.02; cardiac index: R = 0.17, P = 0.21). However, echocardiograms with RVSP ≥48 mm Hg had 100% sensitivity for detecting hemodynamically severe POPH, with 100% negative predictive value. In external validation of 13 paired echocardiograms and RHCs, our algorithm had 64% specificity and 100% negative predictive value. Conclusions. Although echocardiogram and RHC hemodynamic estimates were not strongly correlated, these results could potentially negate the current requirement for repeat RHC every 3 mo to maintain POPH MELD exception.