Prevalence and echocardiographic screening for pulmonary hypertension in liver transplantation recipients

Background: Limited data are available on the prevalence of pulmonary hypertension (PH) in liver transplantation (LT) recipients and the usefulness of echocardiography (Echo) as a screening tool. Aim: To examine the comorbid rate of PH and the accuracy of Echo in estimating pulmonary arterial pressure (PAP) in living-donor LT recipients. Methods: We reviewed all adult LT recipients who underwent screening Echo and right heart catheterization (RHC) between 2003 and 2017. We determined the prevalence of PH using RHC-derived pulmonary arterial pressure (PAP) recorded at the time of LT. To examine the accuracy of Echo, we compared the Echo-estimated systolic PAP (Echo-SPAP) with the RHC-derived SPAP (RHC-SPAP). Results: We retrospectively analyzed data from 81 LT patients (48 men; mean age, 54 [49–59] years; mean PAP (MPAP), 17 [14-21] mmHg). Among them, 9 (11%) patients exhibited an MPAP of ≥25 mmHg and 21 (26%) an MPAP of >20 mmHg. Tricuspid regurgitation flow was not detectable on the Echo findings of 15 (19%) patients. In the remaining 66 patients, the Echo-SPAP significantly correlated with the RHC-SPAP (p=0.01, ρ=0.31). Notably, however, the Echo-SPAP (33 [27-38] mmHg) was significantly higher than the RHC-SPAP (25 [20-30] mmHg; p=0.02, Wilcoxon rank sum test). In addition, the Echo-SPAP was higher than the RHC-SPAP by ≥20% in 42/66 (52%) patients. Conclusions: PH with an MPAP of >20 mmHg was observed in 26% of our living-donor LT cohort. Echo is useful for estimating PAP and screening for PH. However, the Echo-SPAP cannot be calculated in 1 out of 5 patients and it often overestimates PAP, which should be kept in mind when interpreting its results.