Transcriptional changes of the extracellular matrix in chronic thromboembolic pulmonary hypertension govern right ventricle remodeling and recovery.

Chronic thromboembolic pulmonary hypertension (CTEPH) leads to progressive right ventricular (RV) dysfunction. Pulmonary endarterectomy (PEA) is an established treatment for these patients; however, the molecular mechanisms underlying RV remodeling and recovery remain poorly understood. Here we show that RNA sequencing and histological analysis of RV free wall and septal biopsies from patients with CTEPH reveal extracellular matrix enrichment and cytoskeletal remodeling before PEA. These changes were consistent across an exploratory and confirmatory cohort. Post-PEA samples showed reversal of both histological and transcriptional abnormalities. Key signaling molecules-ANKRD1, IL7R and SERPINE1-were implicated in fibrotic and proliferative pathways, as confirmed in human tissues and experimental models. Our findings identify a reversible gene expression and structural remodeling signature in the RV, linking hemodynamic unloading with molecular recovery. These insights suggest potential therapeutic targets to modulate maladaptive RV remodeling in CTEPH and improve outcomes beyond surgical intervention.