High variability in reporting of right ventricle contouring technique and body surface area methodology in cardiac magnetic resonance studies of patients with repaired Tetralogy of Fallot: A systematic review.

Background: Timing of pulmonary valve intervention (PVI) for pulmonary regurgitation in patients with repaired Tetralogy of Fallot (TOF) is guided by right ventricle (RV) volumetric/function assessment on cardiac magnetic resonance (CMR) indexed to actual body surface area (BSA). However, different RV contouring techniques and BSA formulae exist with significant variability in reported measurements. We aimed to review the protocols reported in CMR studies of PVI in TOF.

Methods: A search of electronic databases (Embase and MEDLINE) was performed to identify studies published between 28/2/10-28/2/25 which assessed adults with repaired TOF before and after PVI using CMR. RV contouring methods and BSA formulae were reviewed.

Results: After screening 610 references, a total of 27 studies met criteria and were included. All studies were of only level III or level IV (lowest) levels of evidence. Most studies (81%, 22/27) did not specify the RV contouring technique used and none defined the RV basal slice. Of the 5 studies describing the RV contouring technique, 4 excluded trabeculations/papillary muscles from the RV volume and 1 included these structures. No studies reported the formula used to calculate actual BSA.

Conclusion: RV contouring technique and BSA methodology utilised in CMR studies of PVI in TOF is poorly reported. Given the importance of severity thresholds for RV volumes in triggering intervention in clinical practice, clear reporting and standardisation of RV contouring and BSA methodology should be mandatory. Further research into the optimal RV thresholds for PVI based on clear contouring methods is required.