Abstract 9978: Effect of Balloon Pulmonary Angioplasty on Respiratory Function in Patients With Chronic Thromboembolic Pulmonary Hypertension: Different Effects According to the Lung Field Involved

Abstract

Background: Treatment of chronic thromboembolic pulmonary hypertension (CTEPH) with balloon pulmonary angioplasty (BPA) reportedly improves hemodynamics, exercise capacity, and right ventricular function. However, the effect of BPA on respiratory functions is unclear. Methods: We enrolled consecutive patients with inoperable CTEPH who underwent BPA. BPA was performed primarily on the lower lobe arteries during the first series and on the upper and middle lobe arteries during the second series. We examined right heart catheterization, the respiratory function test, and the cardiopulmonary exercise test, and compared the change in these parameters according to the BPA performed field (divided into the upper-middle and lower lobe before BPA, after BPA, and the follow-up period). Results: In total, 62 BPA sessions were performed in 13 CTEPH patients. Hemodynamics significantly improved after BPA (mPAP: 44±8 to 24±5 mmHg, PVR: 818±383 to 293±68 dyne/s/cm-5), and WHO-FC improved from 3.1±0.3 to 2.2±0.6 after BPA. Hemodynamic improvement tended to be larger in BPA in the lower lung field. The %DLco significantly decreased (p=0.001) in BPA in the lower lung field, and did not appear to recover during the follow-up period. In contrast, %DLco significantly increased in BPA in the upper-middle lung field (p=0.030), and tended to increase until the follow-up period (p=0.077) (Fig). In addition, VE/VCO2 slope significantly improved after BPA in the lower lung field (p=0.014), and showed further improvement at the follow-up period (p=0.007); however, VE/VCO2 slope remained unchanged after BPA in the upper-middle lung field (Fig). Furthermore, during follow-up, change in %DLco and VE/VCO2 slope were significantly different between lower and upper-middle lung field BPA performed (p<0.001 and p=0.020, respectively, Fig). Conclusions: We observed that the effect of BPA in CTEPH patients may have a different effect on respiratory function according to the lung field.