Abstract Body (Do not enter title and authors here): Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a potentially life-threatening disease characterized by unresolved pulmonary embolism. Over the past decade, balloon pulmonary angioplasty (BPA) has been increasingly implemented in a number of centers. The Japan BPA registry was designed to evaluate the effects and safety of BPA from a nationwide perspective.
Methods: This nationwide BPA registry enrolled 1202 patients who underwent BPA at 44 hospitals between April 2018 and March 2023.
Results: A total of 5207 BPA procedures were performed, with a median of four procedures (interquartile range, 3–5 procedures) per patient. High-volume centers (> 50 procedures per year) accounted for 20.5% of the 44 hospitals, whereas 40.8% of BPA procedures were performed in low-volume centers (1–50 procedures per year). BPA significantly improved symptoms, six-minute walk distance, brain natriuretic peptide levels, oxygenation, and hemodynamics, with a 55.6% reduction in pulmonary vascular resistance. The BPA-related death rate was 0.2%, and there was no significant difference between high- and low-volume centers. Severe lung injuries related to BPA were more common in low-volume centers (1.3%) than in high-volume centers (0.3%) (p < 0.001). In the Kaplan-Meier analysis, the estimated survival at 3 years was 94.7% (95% confidence interval: 92.5–96.3%). In the multivariate Cox regression analysis, older age and higher right atrial pressure were associated with an increased risk of mortality, whereas female sex and high-volume centers were associated with a reduced risk of mortality.
Conclusions: This nationwide registry data demonstrated that BPA is a safe and effective therapeutic option for patients with CTEPH. The incidence of severe complications related to BPA was higher in centers with lower procedural volumes than in high-volume centers, although there was no difference in BPA-related death.