Non-Cirrhotic Intrahepatic Portal Hypertension Induced Pulmonary Arterial Hypertension: Is it More Prevalent than we Think?

Introduction Porto-Pulmonary Hypertension (PoPH) belongs to WHO group I, Pulmonary Arterial Hypertension (PAH). It has a prevalence of 0.5-5% and is potentially curable with liver transplant. Non-cirrhotic intrahepatic portal hypertension (NCIPH) is a rare cause of PoPH that shares clinical features of advanced right heart failure. Based on review of the literature and Pulmonary Hypertension (PH) registries, most studies report the prevalence of patients with the liver cirrhosis with little to no data on the incidence of PoPH amongst the non-cirrhotic patient population. In this report, we describe the two cases of “missed” NCIPH and PoPH who were diagnosed in our institution within the span of six months. Case Reports The first patient was a 36 year old African American female who carried an initial diagnosis of SLE and ITP. She was on combination therapy with prostacyclin and endothelin receptor antagonist for the treatment of PAH. Her recurrent epistaxis from thrombocytopenia was refractory to therapy with prednisone, Rituximab, Romiplostim requiring multiple PRBC transfusions. Abdominal imaging revealed splenomegaly while liver biopsy demonstrated Nodular Regenerative Hyperplasia (NRH) without cirrhosis. The second patient, a 44 year old Chinese female, was initially diagnosed with idiopathic PAH. She was also identified to have ITP and showed no significant response to dexamethasone. On hospital admission, both patients presented with large volume ascites, splenomegaly and dependent edema. While in the ICU, they underwent RHC with assessment of Hepatic Venous Pressure Gradient (HVPG) demonstrating severely elevated pressures at 14 mmHg (Normally ≤ 5 mmHg) (Table 1). Liver biopsy was performed during the same procedure without complications. The pathology was consistent with NCIPH. Summary Our report illustrates the importance of considering the diagnosis of NCIPH in patients with PH and refractory ITP, particularly in the setting of splenomegaly and lack of overt cirrhosis. Due to an estimated 50% of patients with NCIPH that go on to develop portal hypertension, it is important to consider this diagnosis when evaluating patients with PH as the treatment strategy differs from idiopathic and connective tissue disease-associated PAH. Given the limited risk of HVPG measurement as part of the evaluation of patients with PAH, our single center experience would suggest screening for NCIPH in select patients and embracing this etiology in the differential.