Prognostic significance of right atrial volume and interval changes in patients with idiopathic pulmonary arterial hypertension

Abstract

Introduction

Idiopathic pulmonary arterial hypertension (IPAH) is a severe condition characterized by a poor prognosis, rapid deterioration, and high mortality in the absence of lung transplantation. However, non-invasive prognostic markers in assessing IPAH remain uncertain. We aimed to investigate the prognostic significance of chest CT and alterations in heart contours on chest radiography (CXR) in predicting adverse outcomes in IPAH patients.

Methods

A retrospective study analyzed medical records of IPAH patients who underwent right heart catheterization and chest CT at a tertiary center between 2001 and 2023. Clinical, hemodynamic, and CT findings, and changes (Δ) in heart contours on CXR were assessed. Adverse events were defined as IPAH-related death or lung transplantation. Cox regression models evaluated the predictive power of these parameters.

Results

In 80 patients with IPAH (mean age 42.6 years; 75 % females), the 3- and 5-year survival rates were 65.8 % and 55.1 %, respectively. Adverse events were associated with a history of cardiac arrest (Hazard ratio [HR], 11.67, p = 0.02), mean pulmonary artery pressure (HR, 1.04, p = 0.001), creatinine (HR, 4.12, p < 0.001), 6-min walk distance (HR, 0.997, p = 0.03), CT-derived right atrial (RA) volume index (HR, 1.01, p = 0.02), and ΔRA contour on CXR (HR, 1.27, p < 0.001). Combined clinical, CT, and CXR findings showed a 3-year event-free survival predictive accuracy of 82.2 % (95 % CI, 69.8–94.7), outperforming clinical factors alone.

Conclusion

Rapid increases in RA contour on CXR and CT-derived RA volume index were associated with adverse outcomes in IPAH. Assessing these parameters may be helpful in identifying patients who require proactive treatments.