Pulmonary veno-occlusive disease: Insights from animal models

Pulmonary veno-occlusive disease (PVOD) is a subtype of pulmonary hypertension (PH) with a poor prognosis. Patients with PVOD develop a gradual increase in pulmonary vascular resistance (PVR) and right heart failure. PVOD can occur sporadically (known as sporadic PVOD or sPVOD) or be inherited (known as heritable PVOD or hPVOD). The estimated incidence rate of PVOD is 0.1-0.5 cases per million, which is about ten times less frequent than that of pulmonary artery hypertension (PAH), a condition closely related to PVOD. Because many clinical features of PVOD overlap with those of PAH, PVOD patients are often misdiagnosed as PAH. There is a critical need for early and accurate diagnosis of PVOD and effective therapeutics for PVOD developed based on its underlying etiology. In this review, we highlight the similarities and distinctions between PAH and PVOD, recent advances in understanding the mechanisms of vascular remodeling in PVOD using animal models, and emerging therapeutic strategies specifically targeting PVOD informed by these insights.