Original Research: Pulmonary Vascular DiseaseEffect of Balloon Pulmonary Angioplasty on Respiratory Function in Patients With Chronic Thromboembolic Pulmonary Hypertension

BackgroundBalloon pulmonary angioplasty (BPA) in chronic thromboembolic pulmonary hypertension (CTEPH) improves hemodynamics and exercise capacity. However, its effect on respiratory function is unclear. Our objective was to investigate the effect of BPA on respiratory function.MethodsWe enrolled patients with inoperable CTEPH who underwent BPA primarily in lower lobe arteries (first series) and upper and middle lobe arteries (second series). We compared changes in hemodynamics and respiratory function between different BPA fields.ResultsSixty-two BPA sessions were performed in 13 consecutive patients. Mean pulmonary arterial pressure and pulmonary vascular resistance significantly improved from 44 ± 8 to 23 ± 5 mm Hg and 818 ± 383 to 311 ± 117 dyne/s/cm−5. The percent predicted diffusion capacity of lung for carbon monoxide (Dlco) decreased after BPA in the lower lung field (from 60% ± 8% to 54% ± 8%) with no recovery. Percent Dlco increased after BPA in the upper middle lung field (from 53% ± 6% to 58% ± 6%) and continued to improve during the follow-up (from 58% ± 6% to 64% ± 11%). The ventilation/Co2 production (V˙e/V˙co2) slope significantly improved after BPA in the lower lung field (from 51 ± 13 to 41 ± 8) and continued to improve during the follow-up (from 41 ± 8 to 35 ± 7); however, the V˙e/V˙co2 slope remained unchanged after BPA in the upper/middle lung field. Changes in % Dlco and the V˙e/V˙co2 slope differed significantly between lower and upper/middle lung fields.ConclusionsThe effect of BPA on respiratory function in patients with CTEPH differed depending on the lung field.