Portopulmonary hypertension: Current developments and future perspectives

Portopulmonary hypertension (POPH) is a severe pulmonary vascular disease secondary to portal hypertension and a subset of Group 1 pulmonary hypertension (PH). The pathological changes of POPH are indistinguishable from other PH phenotypes, including endothelial dysfunction, pulmonary vasoconstriction, and vascular remodeling. These changes cause a progressive increase in pulmonary vascular resistance and afterload of the right ventricle, eventually leading to severe right heart failure. The prognosis of POPH is extremely poor among untreated patients. POPH is associated with a high risk of death after liver transplantation (LT), and severe POPH is considered an absolute contraindication for LT. However, pulmonary arterial hypertension (PAH)-targeted therapies are administered to patients with POPH, and aggressive drug treatment significantly optimizes pulmonary hemodynamics and reduces the risk of death. Therefore, early diagnosis, aggressive PAH-targeted therapies, and proper selection of liver transplant candidates are vital to reduce the risk of surgery and improve clinical outcomes. This article aims to review the results of previous studies and describe biological mechanisms, epidemiology, potential risk factors, and diagnostic approaches of POPH. Moreover, we introduce recent therapeutic interventions for the early diagnosis of POPH and efficient clinical management decisions.