Pulmonary Hypertension After Liver Transplantation, a Case Study in Dysfunctional Liver‐Lung Communication

Portopulmonary hypertension (PoPH) is a type of pulmonary vascular disease that occurs in the context of portal hypertension. Liver transplantation (LT) can be beneficial and is believed to resolve PoPH in about half of all cases. Uncommonly, however, new‐onset pulmonary hypertension (PH) can occur in patients following LT without any prior history of pulmonary vascular disease, which may be associated with high morbidity and mortality and is believed to be a result of dysfunctional liver‐lung communication. PH post‐LT may present heterogeneously, with different implications for survival and hepatic graft function: some individuals may develop acute but transient right‐sided pressure elevation and cardiac dysfunction soon after LT, whereas others may succumb to pulmonary vascular remodeling and right heart failure many years after transplantation. Much remains unknown regarding the epidemiology, timing, risk factors, underlying mechanisms, and natural history of PH post‐LT. In this narrative review of two illustrative cases (one with de novo PH post‐LT, one with worsening PH post‐LT), a retrospective single center analysis and review of the literature, we summarize the current state of knowledge regarding PH post‐LT and highlight key gaps in our understanding of how inter‐organ communication drives pulmonary vascular disease following liver transplantation.