Assessment of atrioventricular interaction and response to balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension using cardiac MRI

Objectives This study aimed to evaluate atrioventricular interaction in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and to determine the effects of balloon pulmonary angioplasty (BPA) on reversible cardiac remodeling assessed by cardiac magnetic resonance (CMR) imaging. Materials and methods In this prospective single-center study, 52 patients with CTEPH (mean age: 58 ± 11 years; 34 females) and 35 healthy controls underwent CMR imaging. Twenty-five patients (mean age: 60 ± 12 years; 19 females) who underwent BPA received follow-up CMR at a mean interval of 7 ± 5 months. Cardiac structure, function, myocardial deformation, and epicardial adipose tissue (EAT) were assessed based on cine images. Results Compared with controls, patients with CTEPH demonstrated predominant right-sided cardiac involvement, characterized by reduced right ventricular ejection fraction ( p < 0.001), marked enlargement of right atrial (RA) and ventricular (RV) volumes, and severely impaired right heart strain (all p < 0.001). Left ventricular systolic function was relatively preserved, with mildly impaired global circumferential strain ( p = 0.011) and a trend toward attenuated longitudinal strain ( p = 0.055), whereas all left atrial (LA) strain components were markedly impaired (all p < 0.05), indicating altered atrioventricular interaction. Following BPA, the right heart structure, RV function and deformation, and LA conduit strain improved. EAT was comparable between groups and remained unchanged after BPA. Conclusion CTEPH involves marked right heart systolic dysfunction and early biventricular diastolic abnormalities associated with impaired atrioventricular interaction. BPA could reverse cardiac remodeling by improving right heart structure, function, and partially recovering atrial deformation after pressure relief. Key Points Questions Atrioventricular interaction abnormalities and reversible cardiac remodeling in chronic thromboembolic pulmonary hypertension (CTEPH) after balloon pulmonary angioplasty (BPA) remain insufficiently characterized. Findings CTEPH is associated with impaired right heart strain and altered atrioventricular interaction; BPA improves right heart structure and function and partially recovers atrial deformation. Critical relevance statement Cardiac MRI-derived myocardial deformation and atrial phasic function may reflect alterations in atrioventricular interaction in CTEPH and complement conventional metrics in assessing cardiac remodeling and recovery after BPA.