A63-39 Progressive Pulmonary Artery Dilation as a Surrogate of Worsening Right Heart Failure in Pulmonary Hypertension

Abstract Introduction Pulmonary artery (PA) dilatation is a common imaging finding in pulmonary arterial hypertension (PAH) patients and may reflect right ventricular pressure overload and vascular remodeling. Its prognostic significance, particularly regarding hemodynamic deterioration and functional capacity, remains uncertain. Case Description Two women with connective tissue disease (CTD)-associated PAH were identified from a comprehensive care center. Both demonstrated progressive PA enlargement on serial computed tomography (CT) imaging despite advanced therapy. Case 1: A 49-year-old woman with CTD-associated PAH initially presented in 2008 with severe PAH and left recurrent laryngeal nerve paralysis due to right PA enlargement. She was treated with sildenafil, later escalated to dual therapy with ambrisentan. Her condition remained stable until 2016, when rheumatoid arthritis progressed. CT imaging revealed a markedly dilated main PA measuring 5.4 cm. With worsening symptoms, therapy was intensified to ambrisentan, selexipag, and riociguat. Case 2: A A 49-year-old woman with CTD-associated PAH and hepatitis B was diagnosed in 2013. She transitioned from ambrisentan to macitentan, selexipag, and riociguat. Upadacitinib was discontinued for abnormal liver function tests. In May 2025, sotatercept was initiated, resulting in significant improvement in dyspnea and normalization of liver function tests. Arthritis remained well controlled without steroids. Demographic, clinical, and hemodynamic data were collected, and CT images reviewed. Both patients exhibited progressive PA dilation over time, yet hemodynamic parameters and six-minute walk distance (6MWD) did not consistently correlate with imaging changes (Figure). Conclusion This two-patient case series highlights the complexity of interpreting PA dilation in PAH. Although marked vascular enlargement was observed, it did not reliably predict worsening hemodynamics or functional decline. Recent studies suggest that increasing PA diameter may be associated with RV dysfunction and reduced exercise capacity, but its independent prognostic value remains unclear. These findings underscore the need to integrate imaging, hemodynamic, and functional assessments for comprehensive risk stratification in PAH This abstract is funded by: none