Balloon pulmonary angioplasty relieves haemodynamic stress towards untreated-side pulmonary vasculature and improves its resistance in patients with chronic thromboembolic pulmonary hypertension

AIMS Chronic thromboembolic pulmonary hypertension (CTEPH) is characterised by organised thrombotic obliteration of major vessels and small-vessel arteriopathy in the non-thrombosed vessels. The aim of this study was to investigate the impact of balloon pulmonary angioplasty (BPA) on the non-BPA-side pulmonary vasculature in patients with CTEPH. METHODS AND RESULTS This study explored the outcomes of 20 unilateral BPA sessions in 13 CTEPH patients. We measured the pulmonary vascular resistance (PVR), pulmonary artery (PA) flow in the BPA-side and non-BPA-side lungs, respectively, using phase contrast MRI and cardiac catheterisation. The interval from BPA to the follow-up evaluation was 92.8±52.0 days. A single session of BPA decreased mean PA pressure from 37.4±6.2 to 30.9±6.5 mmHg (p