LAUSR

Portopulmonary hypertension (POPH) is characterized by portal hypertension leading to splanchnic vasodilatation and formation of portosystemic shunts. These phenomena contribute directly to a decrease in peripheral vascular resistance, which is exacerbated by vasoactive substances able to bypass the liver through the portosystemic shunts, ultimately leading to a hyperdynamic state. 1 The increased blood flow itself may increase pulmonary artery pressure, also in the absence of pulmonary vascular remodeling. True POPH with increased pulmonary vascular resistance (PVR ≥ 3 Wood units) is found in approximately 5% of liver transplantation candidates. 2 Although this prevalence is relatively low, it is important to screen for POPH through echocardiography as the 5-year survival is only 40%. 3 Screening is especially important in liver transplantation candidates as the mortality after liver transplantation is higher when pulmonary hypertension (PH) is present, but clear cutoffs for estimated pulmonary artery pressure are lacking. 4 When systolic pulmonary artery pressure (sPAP) is >50 mmHg and/or signs of right ventricular (RV) hypertrophy or dysfunction are present, a diagnostic right heart catheterization is recommended. However, with lower values of estimated sPAP, it is not clear whether