[Hemodynamic changes with serial balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension]

Objective: To monitor hemodynamic changes during serial balloon pulmonary angioplasty (BPA) for chronic thromboembolic pulmonary hypertension (CTEPH). Methods: General clinical data of CTEPH patients diagnosed from October 2017 to January 2022 in Beijing Chaoyang Hospital were collected, and 83 patients who underwent at least 1 BPA treatment were included to analyze their 6 min walking distance, WHO functional class, N-terminal B-type natriuretic peptide precursor (NT-proBNP), troponin I (cTnI) and haemodynamic indices. Baseline and follow-up after the final BPA clinical data and hemodynamics, functional status and serial hemodynamics before each series of BPA were collected to evaluate the efficacy of BPA for CTEPH patients. Complications and managements were documented to confirm the safety of BPA for CTEPH patients. Results: Three hundred and forty BPA procedures were performed in 83 CTEPH patients. The median number of BPA procedures was 4.0 and a total of 2104 vessels were dilated. In general, mPAP [from 50.0(42.0-55.25) mmHg(1 mmHg=0.133 kPa) to 32.0(27.0-42.0) mmHg, P<0.001], PVR[from (806.6±323.2) dyn·s·cm^-5 to 420.0(295.0-613.5) dyn·s·cm^-5, P<0.001] were significantly improved compared with baseline, but not CO and CI. Functional parameters including WHO functional class Ⅰ/Ⅱ/Ⅲ/Ⅳ (from 0/35/34/14 to 43/32/7/1, P<0.001), 6MWD [from 364.5(300.0-429.5)m to 461.0(409.0-501.0)m, P<0.001], NT-proBNP [from 1 357.0(232.0-2 715.0) ng/L to 141.0(57.0-627.8) ng/L,P<0.001] were significantly improved compared with baseline. A cumulative (compared to baseline) and serial (compared to preceding BPA session) analysis of the sequential BPA session confirmed that a major hemodynamic improvement in PVR and mPAP occurred in the first 3 serial BPA treatments. There was a dose-response relationship: the more segments that were treated, the greater were the subsequent reduction in PVR and mPAP. There were 32.0 complications (9.4%) associated with BPA procedures, and the most common complication was pulmonary hemorrhage caused by catheter-related vascular injury. Conclusions: BPA is an effective and safe alternative for technically non-operable CTEPH patients. The hemodynamic benefits of BPA in CTEPH patients were cumulative and correlated with the total number of vessels successfully dilated.