Evaluation of Right Ventricular Function on Cardiac Magnetic Resonance Imaging and Correlation With Hemodynamics in Patients With Chronic Thromboembolic Pulmonary Hypertension

Background: Balloon pulmonary angioplasty (BPA) is an alternative therapy for chronic thromboembolic pulmonary hypertension (CTEPH). Right heart catheterization (RHC) is essential to evaluate the efficacy of BPA. Cardiac magnetic resonance imaging (CMR) is also now used to assess the structure and function of the right heart non-invasively. The aim of this study was to correlate improvement in CMR with that on RHC, and compared with improvement in other non-invasive findings after BPA. Methods and Results: Forty-two patients underwent BPA between July 2012 and March 2015, and CMR, electrocardiography (ECG), and echocardiography were performed at the same time before and 6 months after BPA. Median pulmonary vascular resistance (PVR) was improved from 5.7 Wood units (IQR, 3.1–7.9 Wood units) to 2.7 Wood units (IQR, 1.6–3.9 Wood units; P<0.001). Changes in PVR were correlated with the changes in 5 CMR, 9 ECG, and 5 echocardiography parameters. On logistic analysis to identify the indicators of improving PH (i.e., PVR <3 Wood units), 4 CMR parameters were independently correlated with PVR change, one of which was median septal inversion ratio (SIR; 0.59; IQR, 0.54–0.63 to 0.54; IQR, 0.50–0.58, P<0.0001). SIR was the best predictor of PH (OR, 1.27; P<0.05). Conclusions: CMR can be used to estimate hemodynamic changes after BPA, and SIR is useful to predict alleviation of PH.