Pulmonary Hypertension SOLAR

The objective of this study is to identify a 129Xe MRI signature associated with PAH-like pulmonary vascular remodeling, consisting of plexiform arteriopathy, smooth muscle cell proliferation, and vascular fibrosis, in IPF and COPD that could be used to identify potential responders vs non-responders to PAH-specific therapies. The central hypothesis is that similar mechanisms and pathways underlie pulmonary vascular remodeling in IPF-PH, COPD-PH, and PAH. However, only a subset of Group 3 PH patients display remodeling consistent with PAH, resulting in responder vs. non-responder phenotypes when treated with PAH-specific therapies. In preliminary studies of subjects treated with Tyvaso, The study team has observed distinct 129Xe MRI signatures at baseline and with therapy depending on patients' underlying lung function. Consistent with this, recent studies using single-cell RNA sequencing (scRNAseq) of the pulmonary vasculature in IPF have demonstrated changes consistent with vascular remodeling.