Abstract 14631: Pulmonary Artery Calcification: A New Threat in Pulmonary Arterial Hypertension

Background: Pulmonary arterial hypertension (PAH) is associated with imbalance between proliferation and apoptosis of pulmonary artery (PA) smooth muscle cells (PASMCs). Recently, we uncovered a role for microRNA-204 (miR-204), whose downregulation sustains the phenotype in time. In systemic vascular disease, miR-204 downregulation increases the Runt-related transcription factor 2 (RUNX2), a key osteogenic factor inducing calcification. The fact that PAH patients live longer increases the odds of developing PA calcification lesions. Interestingly, the presence and development of calcified lesions in PAH have not been explored. We thus hypothesized that miR-204-dependent upregulation of RUNX2 triggers the development of proliferative and calcified vascular lesions within the lungs, thus worsening PAH. Methods/Results: Using CT-scan, we showed that PAH patients (n=50; p<0.05) had significant increase in distal PA calcification compared to control patients matched for age, sex and comorbidities known to prom...