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.

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.

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).

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. Competing Interest Statement The authors have declared no competing interest. Funding Statement This study was supported in part by the National Key Research and Development Program of China 2022YFC2703902 (L.W.), the National Key Research and Development Program of China 2023YFC2507200 (L.W.) and Three-Year Action Plan for Promoting Clinical Skills and Clinical Innovation in Municipal Hospitals (SHDC2024CRI065). Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Our study adhered to the principles of the Declaration of Helsinki and received approval from the ethics committee of Shanghai Pulmonary Hospital (approval number: K16-293). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability all data is available