Right Ventricular Restrictive Physiology Is Associated With Right Ventricular Direct Flow From 4D Flow CMR

Xiaodan Zhao; Phong Teck Lee; Liwei Hu; Ru-San Tan; Ping Chai; Tee Joo Yeo; Shuang Leng; RongZhen Ouyang; Jennifer Ann Bryant; Lynette L S Teo; Rob J van der Geest; James W Yip; Ju Le Tan; Yumin Zhong; Liang Zhong

doi:10.1016/j.jacasi.2024.08.019

Right Ventricular Restrictive Physiology Is Associated With Right Ventricular Direct Flow From 4D Flow CMR

JACC Asia. 2024 Oct 22;4(12):912-924. doi: 10.1016/j.jacasi.2024.08.019. eCollection 2024 Dec.

Authors

Xiaodan Zhao¹, Phong Teck Lee¹, Liwei Hu², Ru-San Tan^{1

3}, Ping Chai^{4

5}, Tee Joo Yeo^{4

5}, Shuang Leng^{1

3}, RongZhen Ouyang², Jennifer Ann Bryant^{1

3}, Lynette L S Teo^{4

5}, Rob J van der Geest⁶, James W Yip^{4

5}, Ju Le Tan^{1

3}, Yumin Zhong², Liang Zhong^{1

3

7}

Affiliations

¹ National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore.
² Duke-NUS Medical School, Singapore.
³ Department of Radiology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
⁴ National University Hospital Singapore, Singapore.
⁵ Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
⁶ Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
⁷ Department of Biomedical Engineering, National University of Singapore, Singapore.

Abstract

Background: Right ventricular restrictive physiology (RVRP) is a common occurrence in repaired tetralogy of Fallot (rTOF). The relationship of RVRP with biventricular blood flow components and kinetic energy (KE) from 4-dimensional (4D) flow cardiovascular magnetic resonance (CMR) is unclear.

Objectives: The purpose of this study was to investigate the association of 4D flow CMR parameters with RVRP in rTOF patients.

Methods: A total of 103 rTOF patients and 62 age and sex-matched healthy control subjects were prospectively recruited. All participants underwent CMR (cine, 2-dimensional phase-contrast, and 4D flow sequences), and cardiopulmonary exercise test in adult populations. RVRP was identified from pulmonary artery flow curve using 2-dimensional phase-contrast images. Biventricular flow components (direct flow, retained inflow, delayed ejection flow, and residual volume) and KE parameters normalized to end-diastolic volume (KEi_EDV) were analyzed encompassing global, peak systolic, average systolic, average diastolic, peak E-wave, and peak A-wave.

Results: Compared with control subjects, rTOF patients had significantly lower RV direct flow and higher RV residual volume (both P < 0.001). All RV KEi_EDV parameters, except peak A-wave, were higher in rTOF patients. In rTOF patients, 70 of 103 (68%) had RVRP, with increasing RV direct flow (27% vs 20%; P = 0.002) and RV peak E-wave KEi_EDV (28.4 vs 20.7μJ/mL; P = 0.015) and decreasing RV residual volume (37% vs 42%; P = 0.039) than rTOF without RVRP. Exercise capacity was impaired in rTOF, although comparable between RVRP subgroups. Multivariable analysis revealed RV direct flow was an independent predictor of RVRP (OR: 1.158; 95% CI: 1.074-1.249; P < 0.001).

Conclusions: RVRP is associated with dilated RV, higher pulmonary regurgitation, and higher RV direct flow. (Integrated Computational modeling of Right Heart Mechanics and Blood Flow Dynamics in Congenital Heart Disease; NCT03217240).

Keywords: 4D flow CMR; flow component; kinetic energy; repaired tetralogy of Fallot; right ventricular restrictive physiology.

Associated data

ClinicalTrials.gov/NCT03217240