Right Heart Remodeling in End-Stage Pulmonary Arterial Hypertension and the Impact of Treatment Intensity

Background Research on the limits of compensatory right heart remodeling and the effects of pulmonary artery hypertension (PAH) targeted therapies on these mechanisms is limited. Method Chest x-ray and echocardiographic data were collected from 143 deceased patients with PAH confirmed by right heart catheterization at their end-stage disease. Right heart remodeling was compared across different PAH treatment strategies. Results This study of 143 deceased PAH patients (49 ± 17 years, 74.1% female) characterized right heart remodeling at the time of death. Mean cardiothoracic ratio (CTR), right atrial area (RAA) and mid-cavity RV linear dimension (RVD) measured by echocardiography were 0.61±0.09, 27 cm² (median 27, IQR 21–38), and 4.97±0.97 cm, respectively, with extremes of 0.88, 102 cm², and 7.50 cm. Intensive therapy resulted in larger CTR (0.63±0.08 vs. 0.60±0.09, p=0.016), RAA (30 [24–40] vs. 25 [19–34] cm², p=0.020), and RVD (5.30±0.97 vs. 4.65±0.85 cm, p<0.001) compared with monotherapy. After adjusting for confounders, intensive therapy independently predicted increases in CTR (0.03, 95% CI 0.00-0.05, p=0.054), RAA (6.63 cm², 95% CI 1.46-11.80, p=0.013), and RVD (0.66 cm, 95% CI 0.34-0.98, p<0.001). Conclusion These findings suggest that more aggressive PAH treatment is associated with greater right heart remodeling, highlighting the complex relationship between therapeutic intervention and disease progression in PAH patients.