The assessment of lung function and residual hypoxemia after balloon pulmonary angioplasty for patients with non-operable chronic thromboembolic hypertension

Background: It has been reported that the efficacy of balloon pulmonary angioplasty (BPA) for patients with non-operable chronic thromboembolic pulmonary hypertension (CTEPH) would be promising. However, some patients have shown poor response in oxygenation and lung function parameter even after hemodynamics improved. The aim of our study was to investigate lung function and oxygenation after BPA. Method: Consecutive 103 patients who underwent BPA from September 2011 to August 2018 were enrolled. We evaluated hemodynamics with right heart catheterization, respiratory function test, arterial blood gas examination, and exercise capacity with 6 minute-walk-distance (6MWD)at baseline and after BPA. Result: At the median 12-month follow-up after the final BPA session, pulmonary vascular resistance, and PaO2 improved significantly (782 ± 378 to 331 ± 187 dynes / sec / cm-5, p Conclusion: BPA could dramatically improve hemodynamics and exercise tolerance. However, arterial oxygenation was not normalized after BPA. Moreover, oxygen desaturation in exercise, and %DLCO were almost unchanged. These observations might suggest the remaining arteriopathy and anastomosis in arteriole or capillary level in CTEPH.