Differences in right ventricular-pulmonary vascular coupling and clinical indices between repaired standard tetralogy of Fallot and repaired tetralogy of Fallot with pulmonary atresia

Purpose: The purpose of this study was to compare ventricular vascular coupling ratio (VVCR) between patients with repaired standard tetralogy of Fallot (TOF) and those with repaired TOF-pulmonary atresia (TOF-PA) using cardiovascular magnetic resonance (CMR). Materials and methods: Patients with repaired TOF aged > 6 years were prospectively enrolled for same day CMR, echocardiography, and exercise stress test following a standardized protocol. Sanz's method was used to calculate VVCR as right ventricle (RV) end-systolic volume/pulmonary artery stroke volume. Regression analysis was used to examine associations with exercise test parameters, New York Heart Association (NYHA) class, RV size and biventricular systolic function. Results: A total of 248 subjects were included; of these 222 had repaired TOF (group I, 129 males; mean age, 15.9 +/- 4.7 [SD] years [range: 8-29 years]) and 26 had repaired TOF-PA (group II, 14 males; mean age, 17.0 +/- 6.3 [SD] years [range: 8-29 years]). Mean VVCR for all subjects was 1.54 +/- 0.64 [SD] (range: 0.43-3.80). Mean VVCR was significantly greater in the TOF-PA group (1.81 +/- 0.75 [SD]; range: 0.78-3.20) than in the standard TOF group (1.51 +/- 0.72 [SD]; range: 0.43-3.80) (P = 0.03). VVCR was greater in the 68 NYHA class II subjects (1.79 +/- 0.66 [SD]; range: 0.75-3.26) compared to the 179 NYHA class I subjects (1.46 +/- 0.61 [SD]; range: 0.43-3.80) (P < 0.001). Conclusion: Non-invasive determination of VVCR using CMR is feasible in children and adolescents. VVCR showed association with NYHA class, and was worse in subjects with repaired TOF-PA compared to those with repaired standard TOF. VVCR shows promise as an indicator of pulmonary artery compliance and cardiovascular performance in this cohort. (C) 2020 Societe franc, aise de radiologie. Published by Elsevier Masson SAS. All rights reserved.