Ventricular flow analysis and its association with exertional capacity in repaired tetralogy of Fallot: 4D flow cardiovascular magnetic resonance study

• Published in: Journal of cardiovascular magnetic resonance 2022-01, Vol.24 (1), p.4-4, Article 4
• Main Authors: Zhao, Xiaodan, Hu, Liwei, Leng, Shuang, Tan, Ru-San, Chai, Ping, Bryant, Jennifer Ann, Teo, Lynette L S, Fortier, Marielle V, Yeo, Tee Joo, Ouyang, Rong Zhen, Allen, John C, Hughes, Marina, Garg, Pankaj, Zhang, Shuo, van der Geest, Rob J, Yip, James W, Tan, Teng Hong, Tan, Ju Le, Zhong, Yumin, Zhong, Liang
• Format: Article
• Language: English
• Subjects: 4D flow CMR; Adult; Blood flow; Cardiopulmonary exercise testing; Cardiovascular disease; Child; Congenital diseases; Development and progression; Ejection; Flow components; Force and energy; Gender; Heart; Heart Ventricles - diagnostic imaging; Humans; Hypertension; Intolerance; Kinetic energy; Magnetic resonance; Magnetic Resonance Spectroscopy; Multivariate analysis; Parameters; Patients; Pediatrics; Predictive Value of Tests; Prognosis; Pulmonary arteries; Repaired tetralogy of Fallot; Resonance; Tetralogy of Fallot; Tetralogy of Fallot - diagnostic imaging; Tetralogy of Fallot - surgery; Veins & arteries; Ventricle; Ventricular Function, Right
• ISSN: 1097-6647; 1532-429X
• DOI: 10.1186/s12968-021-00832-2

Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) allows quantification of biventricular blood flow by flow components and kinetic energy (KE) analyses. However, it remains unclear whether 4D flow parameters can predict cardiopulmonary exercise testing (CPET) as a clinical outcome in repaired tetralogy of Fallot (rTOF). Current study aimed to (1) compare 4D flow CMR parameters in rTOF with age- and gender-matched healthy controls, (2) investigate associations of 4D flow parameters with functional and volumetric right ventricular (RV) remodelling markers, and CPET outcome. Sixty-three rTOF patients (14 paediatric, 49 adult; 30 ± 15 years; 29 M) and 63 age- and gender-matched healthy controls (14 paediatric, 49 adult; 31 ± 15 years) were prospectively recruited at four centers. All underwent cine and 4D flow CMR, and all adults performed standardized CPET same day or within one week of CMR. RV remodelling index was calculated as the ratio of RV to left ventricular (LV) end-diastolic volumes. Four flow components were analyzed: direct flow, retained inflow, delayed ejection flow and residual volume. Additionally, three phasic KE parameters normalized to end-diastolic volume (KEi ), were analyzed for both LV and RV: peak systolic, average systolic and peak E-wave. In comparisons of rTOF vs. healthy controls, median LV retained inflow (18% vs. 16%, P = 0.005) and median peak E-wave KEi (34.9 µJ/ml vs. 29.2 µJ/ml, P = 0.006) were higher in rTOF; median RV direct flow was lower in rTOF (25% vs. 35%, P