Strain Analysis from Transverse CMR Cine Imaging in Congenital Heart Disease: Feasibility, Reproducibility, and Comparison to Global Longitudinal Strain.

Background: Global longitudinal strain (GLS), derived from long-axis cine images (LAX), is a sensitive marker for myocardial dysfunction and a strong predictor for clinical events and future ventricular deterioration. In patients with complex congenital heart disease (CHD) transverse-oriented cine imaging is part of the standard cardiac magnetic resonance (CMR) protocol. We aimed to study the feasibility and reproducibility of strain measurements derived from transverse-oriented cine images (Transverse Strain (TrS)) and compare them with standard GLS. Methods: We retrospectively analyzed CMR cine images from 40 patients (n = 20 Fontan, n = 20 Tetralogy of Fallot (ToF)) and 10 healthy controls. Strain analysis was performed in every subject using both the conventional GLS and the TrS approach. Results: TrS showed high intra- and interobserver reproducibility in patients with CHD (intraclass correlation coefficient (ICC) > 0.75, p < 0.05). Intermethod agreement between TrS and GLS was strong in Fontan patients and in the right ventricle (RV) of ToF patients (ICC > 0.75) but showed a positive bias for TrS in the left ventricle (LV) of ToF patients (mean difference = 5.03) and in both ventricles of healthy controls (mean difference LV = 5.36, RV = 4.01). Conclusions: TrS is feasible and reproducible and may offer a new methodological approach for strain assessment, especially in CHD patients with univentricular physiology and ToF patients. Further studies are needed to validate this new approach and perform correlations to clinical outcomes.