Effects of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension on remodeling in right-sided heart.

Remodeling in the right-sided heart plays an important role in the management of pulmonary hypertension (PH) patients. However, the effect of balloon pulmonary angioplasty (BPA) on right ventricular (RV) and right atrial (RA) morphology of patients with chronic thromboembolic pulmonary hypertension (CTEPH) remains uncertain. This study involved 45 CTEPH patients who underwent BPA with mean pulmonary artery pressure (mPAP) of 37.0 mmHg (all ≥ 25 mmHg). All patients underwent echocardiography and right-heart catheterization at baseline and 3 months after BPA. RV and RA remodeling was assessed as RV and the RA area, and RV systolic function was calculated by averaging peak speckle-tracking longitudinal strain of the RV free-wall (RV free-wall strain). Significant reverse remodeling in the right-sided heart was observed after BPA, resulting in improvement of mPAP and pulmonary vascular resistance (RV area: from 15.0 ± 5.3 to 9.6 ± 3.0 cm ² , p < 0.0001; RA area: from 17.3 ± 6.6 to 13.4 ± 3.8 cm ² , p = 0.0002; RV free-wall strain: from 15.9 ± 5.6 to 21.2 ± 4.9%, p < 0.0001). Furthermore, multiple regression analysis showed that the baseline RV area was an independent predictor of post-BPA normalization of RV systolic function defined as RV free-wall strain ≥ 20% (odds ratio = 1.16, p = 0.0305). Interestingly, significant RV reverse remodeling was also observed after additional BPA even in 18 CTEPH patients with residual pulmonary arterial stenosis, whose mPAP was normalized after BPA (RV area: from 11.5 ± 3.8 to 9.2 ± 3.8 cm ² , p = 0.0045; RV free-wall strain: from 17.2 ± 4.8 to 22.8 ± 7.4%, p = 0.0216). Significant reverse remodeling in the right-sided heart, as well as hemodynamic improvement, was observed in CTEPH patients after BPA.