Background

Chronic thromboembolic pulmonary hypertension results from mechanical obstruction of major pulmonary artery lumina with fibrotic tissue. Main treatment has been pulmonary endarterectomy, a complex surgical procedure removing vascular obstruction. However, at least 40% of patients are not candidates for pulmonary endarterectomy because of technical inoperability, comorbidities, or limited access to surgery. Balloon pulmonary angioplasty (BPA) has emerged as an interventional treatment for these patients.

Objectives

The International BPA Registry (NCT03245268) was designed to investigate BPA practice across 18 established centers in the United States, Europe, and Japan.

Methods

A total of 500 patients were prospectively and consecutively enrolled between March 2018 and March 2020, with follow-up until March 2022. Of these, 484 patients were included in the analysis set.

Results

Regional differences were seen in patient characteristics (fewer patients with prior pulmonary endarterectomy and more elderly women in Japan) and procedural details (less medical pretreatment, more jugular access, more segments and more occlusive lesions treated per session and patient, less conscious sedation, less contrast and less radiation, shorter intervals between BPA sessions in Japan). Female sex, procedure in Europe/United States, pulmonary hypertension medications at any time, and higher baseline pulmonary vascular resistance (PVR), calculated as transpulmonary pressure gradient divided by cardiac output, emerged as independent predictors of complications during BPA. After a median of 5 (Q1-Q3: 3-6) BPA sessions per patient within a median time of 4.9 months (Q1-Q3: 1.7-11.0 months), a 15-mm Hg (38%) decrease in mPAP, a 332 dynes/s/cm−5 (57%) decrease in PVR, and a 3.2% increase in arterial saturation (medians; P < 0.001) were observed, and there were significant improvements in functional class, 6-minute walk distance, serum levels of N-terminal probrain natriuretic peptide, and Borg dyspnea index. BPA complications occurred in 11.3% of sessions and 33.9% of patients and were mostly hemoptyses. No patient died within 30 days of BPA.

Conclusions

Our data are in line with previous reports on changes of clinical and hemodynamic parameters and complication rates of BPA. Centers with more experience providing BPAs were more likely to achieve a higher percentage decrease in PVR.