Riociguat-Discontinue Effects on Right HEART in CTEPH (RED-HEART)

Riociguat and balloon pulmonary angioplasty (BPA) are established standard-of-care interventions for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) with comparable evidence levels. However, the optimal combined treatment strategy remains unclear. Specifically, there is no consensus on whether riociguat should be continued long-term after achieving hemodynamic stability with BPA. Additionally, the long-term effects of riociguat discontinuation on right ventricular (RV) structure and function remain poorly characterized, particularly due to the lack of comprehensive noninvasive evaluations integrating cardiac magnetic resonance (CMR) and echocardiography. This prospective study aims to determine the hemodynamic impact of riociguat discontinuation in inoperable CTEPH patients who have achieved BPA treatment endpoints using right heart catheterization (RHC). Evaluate RV remodeling and functional changes after riociguat cessation through multimodal noninvasive imaging (CMR, echocardiography). Assess safety outcomes and identify potential rebound pulmonary hypertension or decompensated RV dysfunction associated with riociguat withdrawal.