Impact of medical therapy on balloon pulmonary angioplasty outcomes in chronic thromboembolic pulmonary hypertension

Background There is no clear consensus on whether medical therapy prior to balloon pulmonary angioplasty (BPA) should be considered for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Purpose To investigate the impact of medical treatment before the first BPA session on BPA outcomes in patients with inoperable CTEPH and severe hemodynamic impairment. Methods A total of 186 patients underwent 1174 BPA procedures between April 2014 and December 2024 at this university hospital. Of these, 82 had a baseline pulmonary vascular resistance (PVR) ≥5 Wood Units (WU) and completed their BPA treatment. Clinical characteristics and hemodynamics were assessed at three time points: (1) at diagnosis ("baseline"), (2) before the first BPA session ("before BPA"), and (3) 6 to 12 months after the final BPA session ("after BPA"). Results Seventeen patients were treated with subcutaneous Treprostinil, 41 with Riociguat, and 24 did not receive medical therapy prior to BPA. At baseline, before the initiation of medical therapy, the Treprostinil group exhibited the highest right ventricular afterload and the lowest cardiac output (CO) (mean pulmonary artery pressure (mPAP) 57±12mmHg, p=0.015; PVR 12.0±2.4WU, p<0.001; CO 4.0±0.9L/min, p = 0.045), while there was no difference between the Riociguat group (mPAP 49±8mmHg, PVR 8.3±2.4WU, CO 4.6±0.9L/min) and the group without medical therapy (mPAP 46±12mmHg, PVR 8.2±2.6WU, CO 4.3±0.9L/min; all p>0.05). However, all three groups achieved a comparable hemodynamic profile before BPA and after completing BPA. The relative reduction in right ventricular afterload was significantly greater in the Treprostinil group (mPAP -43%, p=0.097; PVR -62%, p=0.029) compared to the Riociguat group (mPAP -39%; PVR -52%) and the group without medical therapy (mPAP -28%; PVR -38%). Treprostinil could be discontinued in 11 (65%) patients, while Riociguat was stopped in 13 (32%). There were no significant differences between the groups regarding the required number of BPA sessions or pulmonary injury rates. Conclusions Our findings indicate that pre-treatment with Treprostinil before BPA can significantly reduce right ventricular afterload in inoperable CTEPH patients, leading to similar final hemodynamic outcomes compared to those not receiving therapy. Treprostinil induced the largest hemodynamic improvements and could be safely discontinued in the majority of patients without affecting the overall BPA results.