Abstract 12204: Effects of Percutaneous Transluminal Pulmonary Angioplasty on Respiratory Functions in Patients With Chronic Thromboembolic Pulmonary Hypertension

Abstract

Introduction: Percutaneous transluminal pulmonary angioplasty (PTPA) is an emerging therapeutic strategy to improve hemodynamics and prognosis of patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, it remains to be examined whether PTPA also improves respiratory functions in those patients. Methods and Results: From July 2011 to May 2015, 69 patients with inoperable CTEPH (median age 62 yrs., female 57/69 (83%)) underwent PTPA in our hospital. In 29 of them (36%), we examined respiratory functions, including %VC, FEV1.0%, %DLco, A-a DO 2 and intra-pulmonary shunt before and after PTPA procedure. Intra-pulmonary shunt was calculated using arterial and pulmonary arterial blood samples during administration of pure oxygen. A mean of 4.8 PTPA procedures were performed, and hemodynamics and respiratory functions were examined before and after the treatment. Mean pulmonary arterial pressure (41 ± 8 to 26 ± 7 mmHg, P<0.01), pulmonary vascular resistance (9.4 ± 4.0 to 4.0 ± 1.7 Wood unit), 6-min walk distance (372±120 to 472±143 meters, P<0.01) and brain natriuretic peptide (141±155 to 38±37 pg/ml, P<0.01) were significantly improved after PTPA. Furthermore, saturation of oxygen measured in room air (SaO2, 87 ± 5 to 91 ± 5%, P<0.01), A-a DO 2 (48 ± 10 to 35 ± 11 torr, P<0.01) and intra-pulmonary shunt (24 ± 7 to 21 ± 5 %, P<0.01) were also significantly ameliorated. SaO 2 and intra-pulmonary shunt before PTPA were significantly correlated ( r 2 =0.26, P<0.01). Changes in SaO 2 after PTPA were also significantly correlated with those in intra-pulmonary shunt after the procedures ( r 2 =0.40, P<0.01) (Figure). In contrast, PTPA had no significant effects on %VC, FEV1.0% or %DLco. Conclusions: These results indicate that PTPA improves not only pulmonary hemodynamics but also oxygenation capacity with a resultant decrease in intra-pulmonary shunt.