Ground-Glass Opacities in Pulmonary Arterial Hypertension-Results from the PVDOMICS Study.

Rationale: Pulmonary hypertension (PH) is associated with significant morbidity and mortality. Ground-glass opacities (GGOs) are common in Group 1 PH, but their clinical significance is unclear. Objectives: We sought to characterize the clinical features and outcomes of patients with Group 1 PH with and without GGOs in the PVDOMICS study, a prospective multicenter cohort study aimed at deep phenotyping PH. Methods: Patients with incident and prevalent PH were enrolled across seven U.S. centers. We included patients with Group 1 PH and excluded those with parenchymal lung disease or without chest imaging, resulting in a cohort of 242 patients. Results: GGOs were common among patients with Group 1 PH (43% prevalence), associated with female sex, younger age, prostanoid use, and longer disease duration. GGOs were more common among patients with familial pulmonary arterial hypertension and pulmonary veno-occlusive disease. GGOs were associated with established markers of disease severity, including echocardiographic (right ventricular systolic pressure and tricuspid annular plane systolic excursion), biomarkers (N-terminal pro B-type natriuretic peptide), and worse hemodynamics (higher mean pulmonary artery pressure, pulmonary vascular resistance, and pulmonary artery wedge pressure). GGOs were associated with worse transplant-free survival (hazard ratio, 2.49; 95% confidence interval = 1.43-4.32; P = 0.001) and had independent prognostic value for predicting transplant-free survival after adjusting for European Society of Cardiology and European Respiratory Society risk stratification (hazard ratio, 2.19; 95% confidence interval = 1.20-3.99; P = 0.01). Conclusions: Overall, GGOs were associated with specific clinical characteristics and disease phenotypes, as well as worse hemodynamics, longer disease duration, prostanoid use, and worse survival. Future studies evaluating the pathophysiology and "omic" correlates of GGOs are warranted. Clinical trial registered with www.clinicaltrials.gov (NCT02980887).