Study on the improvement of right ventricular structure and function after balloon pulmonary Angioplasty in chronic thrombotic pulmonary hypertension patients with different degrees of pulmonary arterial hypertension by echocardiography

Objective: Analyze the improvement of right heart structure and function in CTEPH patients with different degrees of pulmonary hypertension after BPA treatment, in order to provide a basis for determining the effectiveness of BPA treatment, and to screen patients with different treatment effects and adjust the subsequent treatment strategies. Method: The patients with CTEPH were selected for preoperative echocardiography, and the right ventricular systolic function parameters, pulmonary artery pressure parameters, left ventricular related parameters were measured; RHC were measured before and after BPA. Perform another echocardiographic within 24 hours after BPA. According to the results of RHC-mPAP before BPA, CTEPH patients were divided into three groups: mild pH, moderate pH and severe PH. Compare the changes in pulmonary artery pressure, right heart structure, and function among three groups of patients after BPA, and analyze their treatment effects. Results: A total of 94 CTEPH patients were included in the study, including 30 mild PH patients, 37 moderate PH patients, and 27 severe PH patients. After BPA, TPVR was significantly reduced in all patients (P=0.029, P=0.002, P=0.004). RHC-sPAP, RHC-mPAP and PVR were decreased in patients with moderate PH (P=0.004, P=0.005, P=0.002) and severe PH (P<0.001, P=0.001, P=0.003); The PAD, RAEDA, RAESA, RVEDA, RVESA, IVCmax, IVCmin and CRIVC in patients with moderate PH were significantly improved. TRA and ∆PTR were also reduced (P<0.001, P=0.001); RAEDA, RAESA, RVEDA, RVESA, FAC, IVCmax, IVCmin were also significantly improved in patients with severe PH. However, patients with mild PH showed no significant changes in the RV volume and hemodynamic parameters. In all patients, RV systolic function parameters (TAPSE, S’, RIMP, RVFAC) did not improve significantly after BPA within 24 hours. Conclusion: BPA has an ideal and rapid therapeutic effect on CTEPH patients with moderate/severe PH, and the therapeutic effect of moderate PH is better than that of severe PH, but not in mild PH; Rapid assessment of patient response after BPA could help screen patients with poor treatment outcomes to consider adjustment for subsequent treatment decisions. After BPA, the structural inverse remodeling of the right heart appeared earlier than the functional inverse remodeling.