Tricuspid annular plane systolic excursion to pulmonary artery systolic pressure ratio in chronic thromboembolic pulmonary hypertension improves with balloon pulmonary angioplasty

Right ventricle (RV)-to-pulmonary artery (PA) coupling measured by the ratio of echocardiography-derived tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) is a meaningful prognostic marker in pulmonary hypertension (PH). It's unclear if balloon pulmonary angioplasty (BPA) treatment of chronic thromboembolic pulmonary hypertension (CTEPH) alters RV-PA coupling measured by TAPSE/PASP. We reviewed CTEPH patients treated with BPA at our institution who had a transthoracic echocardiogram (TTE) before BPA and a follow-up TTE at any point during BPA. TAPSE was obtained from the initial and lattermost TTE; hemodynamics were obtained before each BPA session. Between March 2015 to October 2023, there were 228 patients treated with BPA. After excluding post-PTE patients and those without PH, 67 were included. Initial TAPSE/PASP was 0.39 ± 0.21 mm/mmHg. Using previously defined TAPSE/PASP tertiles in PH (<0.19, 0.19-0.32, >0.32 mm/mmHg), there were 6 patients (9%) in low, 30 (45%) in middle, and 31 (46%) in the high tertiles at baseline. The lower TAPSE/PASP tertiles had more severe baseline hemodynamics (<i>p</i> < 0.001) compared to the high TAPSE/PASP cohort. At follow-up, TAPSE/PASP improved to 0.47 ± 0.20 mm/mmHg (<i>p</i> = 0.023), with 2 (3%), 13 (19%), and 52 (78%) patients in the low, middle, high TAPSE/PASP tertiles, respectively. As patients progress through BPA sessions, the TAPSE/PASP ratio increases, possibly reflecting improved RV mechanics and RV-PA coupling. TAPSE/PASP ratio as a marker of RV-PA coupling can improve with BPA treatment and may be an important measure to follow during treatment of CTEPH.