Right ventricular energetic biomarkers from 4D Flow CMR are associated with exertional capacity in pulmonary arterial hypertension

• Published in: Journal of cardiovascular magnetic resonance Vol. 24; no. 1; p. 61
• Main Authors: Zhao, Xiaodan, Leng, Shuang, Tan, Ru-San, Chai, Ping, Yeo, Tee Joo, Bryant, Jennifer Ann, Teo, Lynette L S, Fortier, Marielle V, Ruan, Wen, Low, Ting Ting, Ong, Ching Ching, Zhang, Shuo, van der Geest, Rob J, Allen, John C, Hughes, Marina, Garg, Pankaj, Tan, Teng Hong, Yip, James W, Tan, Ju Le, Zhong, Liang
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 01.12.2022; BioMed Central; Elsevier
• Subjects: 4D flow CMR; Biomarkers; Blood flow; Carbon dioxide; Cardiopulmonary exercise test; Cardiovascular disease; Comparative analysis; Congenital diseases; Development and progression; Ejection; Flow components; Force and energy; Heart; Heart Ventricles; Humans; Hypertension; Kinetic energy; Laboratories; Magnetic resonance; Magnetic Resonance Spectroscopy; Mathematical analysis; Oxygen consumption; Oxygen uptake; Parameters; Predictive Value of Tests; Pulmonary arterial hypertension; Pulmonary Arterial Hypertension - diagnostic imaging; Pulmonary arteries; Pulmonary hypertension; Regression analysis; Reproducibility; Software; Ventricle; Ventricular Remodeling; Netherlands; Cardiopulmonary exercise test; Pulmonary arterial hypertension; Kinetic energy; 4D flow CMR; Flow components
• ISSN: 1097-6647; 1532-429X
• DOI: 10.1186/s12968-022-00896-8

Cardiovascular magnetic resonance (CMR) offers comprehensive right ventricular (RV) evaluation in pulmonary arterial hypertension (PAH). Emerging four-dimensional (4D) flow CMR allows visualization and quantification of intracardiac flow components and calculation of phasic blood kinetic energy (KE) parameters but it is unknown whether these parameters are associated with cardiopulmonary exercise test (CPET)-assessed exercise capacity, which is a surrogate measure of survival in PAH. We compared 4D flow CMR parameters in PAH with healthy controls, and investigated the association of these parameters with RV remodelling, RV functional and CPET outcomes. PAH patients and healthy controls from two centers were prospectively enrolled to undergo on-site cine and 4D flow CMR, and CPET within one week. RV remodelling index was calculated as the ratio of RV to left ventricular (LV) end-diastolic volumes (EDV). Phasic (peak systolic, average systolic, and peak E-wave) LV and RV blood flow KE indexed to EDV (KEI ) and ventricular LV and RV flow components (direct flow, retained inflow, delayed ejection flow, and residual volume) were calculated. Oxygen uptake (VO ), carbon dioxide production (VCO ) and minute ventilation (VE) were measured and recorded. 45 PAH patients (46 ± 11 years; 7 M) and 51 healthy subjects (46 ± 14 years; 17 M) with no significant differences in age and gender were analyzed. Compared with healthy controls, PAH had significantly lower median RV direct flow, RV delayed ejection flow, RV peak E-wave KEI , peak VO , and percentage (%) predicted peak VO , while significantly higher median RV residual volume and VE/VCO slope. RV direct flow and RV residual volume were significantly associated with RV remodelling, function, peak VO , % predicted peak VO and VE/VCO slope (all P < 0.01). Multiple linear regression analyses showed RV direct flow to be an independent marker of RV function, remodelling and exercise capacity. In this 4D flow CMR and CPET study, RV direct flow provided incremental value over RVEF for discriminating adverse RV remodelling, impaired exercise capacity, and PAH with intermediate and high risk based on risk score. These data suggest that CMR with 4D flow CMR can provide comprehensive assessment of PAH severity, and may be used to monitor disease progression and therapeutic response. https://www. gov . Unique identifier: NCT03217240.