Is Inhaled Therapy Better Than IV? Challenges of PVOD

Abstract

<h3>Introduction</h3> Group 1 pulmonary hypertension (PH) includes pulmonary veno-occlusive disease (PVOD). Diagnosis & management of this rare disease poses multiple challenges. Here we present 2 patients who worsened on systemic vasodilators but responded to inhaled therapy. <h3>Case Report</h3> 76 year old female with sarcoidoisis was admitted with worsening hypoxia requiring high flow nasal cannula. Cardiac sarcoidosis was ruled out by PET-CT (Fig. B, C). Right heart catheterization (RHC) showed severe PH with a negative vasodilator response & normal capillary wedge pressure. PVOD was suspected given hypoxia out of proportion to PH & her CT findings (D, E). She was started on intravenous treprostinil but developed pulmonary edema with worsening V/Q mismatch (F). She was weaned off treprostinil & transitioned to inhaled epoprostenol. She was discharged on inhaled treprostinil only needing nasal cannula. Another 76 year old lady with a recent diagnosis of limited sclerosis was evaluated as an outpatient for dyspnea. Echocardiogram (I) showed PH with a CTA negative for a PE (G). RHC confirmed the diagnosis. She was started on ambrisentan & tadalafil but her hypoxia worsened from 6 to 15 liters. She was referred to cardiology for further evaluation with concern for PVOD. CT chest showed diffuse ground glass pattern & fluid in the fissure (H). Her PFT's showed a normal FEV1, FVC & DLCO of 30%, both consistent with PVOD. She was started on inhaled treprotstinil & has improved since. <h3>Summary</h3> PH specific therapies are directed towards pre-capillary vasculature & pose a risk of causing pulmonary edema in patients with PVOD. Connective tissue disorders are known to be associated with PVOD but there is little data to support the improvement of PH by treating the underlying cause. Right ventricular myocardial biopsies have shown an inherent myocardial defect limiting the response to therapy, leading to poorer outcomes. Given our patients' improvement on inhaled vasodilator therapy we hypothesize that it may help improve V/Q mismatch, but more research is needed to help with management.