Right ventricular adaptation after pulmonary endarterectomy and balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension: a comparative cardiac MRI-based study.

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is associated with elevated right ventricular (RV) afterload and progressive RV remodelling. Balloon pulmonary angioplasty (BPA) has emerged as an established and increasingly used alternative to pulmonary endarterectomy (PEA). This study aimed to evaluate haemodynamic, functional and structural cardiac responses to PEA and BPA, with specific focus on RV reverse remodelling.

METHODS

In this prospective, multicentre cohort study, 93 patients with CTEPH (PEA n=50, BPA n=43) from the Netherlands and Denmark underwent cardiac magnetic resonance imaging, right heart catheterisation, exercise testing and biomarker assessment at baseline and 6 months post-intervention. Longitudinal changes were assessed with repeated-measures ANOVA. A subgroup underwent analysis at 18 months.

RESULTS

BPA patients were older (mean±sd age 68.9±10.1 versus 62.4±11.1 years; p=0.004), and used more pulmonary hypertension medication. PEA-treated patients had higher RV mass index at baseline (40.1±13.5 versus 32.9±12.2 g·m-2; p=0.017), and consistently higher relative RV wall thickness at baseline and follow-up (both 0.4±0.1 versus 0.3±0.1; p<0.001). Both interventions improved RV afterload, function and exercise capacity (all p<0.05). Larger haemodynamic improvement after PEA (mean pulmonary artery pressure and pulmonary vascular resistance; p-interaction ≤0.001) was accompanied by more pronounced RV reverse remodelling, including lower follow-up indexed RV volumes (RV end-diastolic volume indexed 76.2±16.8 versus 92.2±20.2 mL·m-2; p<0.001; and RV end-systolic volume indexed 39.0±15.6 versus 49.0±18.8 mL·m-2; p=0.014).

CONCLUSIONS

In this multicentre European study, both therapies resulted in significant RV reverse remodelling. PEA was associated with larger absolute reductions in indexed RV mass and volumes than BPA. However, remodelling sensitivity to unloading appeared broadly similar across treatments. Despite favourable outcomes following both treatments, our findings emphasise the need for randomised controlled studies, to optimise treatment strategies for operable and inoperable patients.