Impact of Balloon Pulmonary Angioplasty in CTEPH on cardiac and pulmonary physiology as assessed by state-of-the-art cardiovascular magnetic resonance 4D flow haemodynamics

• Applicant: Privatdozent Dr. Sören Jan Backhaus
• Subject Area: Cardiology, Angiology ; Pneumology, Thoracic Surgery
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 560578589

The prevalence of chronic thromboembolic pulmonary hypertension (CTEPH) is on the rise with 26–38 cases/million adults. Following new outcome data highlighting the prognostic impact of already mild increases in pulmonary vascular resistance (PVR) >2 Wood Units (WU), cut-offs for the diagnosis of pulmonary hypertension (PH) have recently been lowered. Technically or clinically inoperable patients or those with residual PH after pulmonary endarterectomy and distal obstructions are forwarded to balloon pulmonary angioplasty (BPA). Monocentric retrospective data from Japan in 170 patients with a median age of 66 years showed 5-year survival (all cause) of 98.7% during a median observation period of 2.8 years. Cardiovascular magnetic resonance (CMR) imaging is the reference standard for the evaluation of cardiac function and morphology. CMR enables myocardial deformation imaging for quantification of cardiac phasic function which bears strong prognostic implications across the field of cardiovascular diseases and unmasks subtle changes in cardiac function before becoming evident on volumetric analyses. CMR is the only imaging technique that allows non-invasive tissue characterisation of diffuse fibrosis (potentially reversible) by the means of T1 and cellular/extracellular volume (ECV) assessment as well as focal replacement fibrosis (irreversible) by late gadolinium enhancement (LGE). Diffuse fibrosis precedes focal replacement fibrosis in a model for increased left ventricular afterload. Conventional velocity-encoded flow sequences allow quantification of pulmonary valve flow kinetics (2D flow). New state-of-the-art time-resolved three-directional CMR phase contrast (4D flow) enables quantification of kinetic energy, pressure differences and haemodynamic forces for right ventriculo-pulmonary artery coupling assessment beyond the means of 2D Flow. Patients with CTEPH referred to the Kerckhoff-Clinic, Campus Justus-Liebig-University Giessen (one of few German high-volume BPA centres), for evaluation and conduction of BPA undergo standard of care diagnostic tests and treatment including conventional echocardiography, right heart catheterisation and non-invasive (computed tomography/CMR) or invasive coronary artery disease examination. BPA is conducted in 5 to 6 consecutive sessions. CMR is performed prior to the first and following the last intervention. In total, n=60 patients will be recruited in a timeframe of 3 years. The objectives of the present study are to; 1. understand the impact of BPA on cardio-pulmonary vascular physiology. 2. quantify the relationship of reduced afterload and cardiac function following BPA. 3. identify prognostic markers prior to and following BPA for major adverse cardiac event as well as quality of life prediction. 4. implement new imaging technology (4D flow).

• DFG Programme: Research Grants
• Co-Investigator: Privatdozent Dr. Christoph Wiedenroth