Cardiovascular Magnetic Resonance Feature Tracking Provides Early Indices of Right Ventricular Systolic Dysfunction in Ebstein's Anomaly

Background: Cardiovascular magnetic resonance feature-tracking analysis (CMR-FT) provides a quantitative assessment of myocardial contraction with potential for diagnostic and prognostic ability in a wide spectrum of diseases. Ebstein's anomaly (EA) is a rare congenital heart disease characterized by apical displacement of the tricuspid valve. It is, however, deemed a disorder of development affecting the global right ventricular myocardium. Aim of our study is to describe the complex contractile mechanics of the functional right ventricle (RV) in patients affected by EA through CMR-FT.

Method: Fifty surgery-free EA patients who had undergone a complete CMR protocol at our institution between January 2017 and December 2020 were selected for the retrospective study. A historical control group of 25 healthy patients was also included. CMR-FT analysis was performed at a dedicated workstation by manually tracing RV endo- and epicardial borders on steady-state-free-precession (SSFP) cine images. RV strain derived values such as global peak systolic radial (GRS) and circumferential (GCS) strain were obtained from short-axis cine images (basal, mid, and apical), while global peak systolic longitudinal strain (GLS) was calculated on a long-axis slice. The magnitude of apical displacement of the tricuspid valve was measured on a four-chamber cine image.

Results: EA patients presented significantly impaired GRS and GCS in respect to controls (19.2 ± 7.6 vs. 29.2 ± 9.5, p <0.0001 and −12.2 ± 4.5 vs. −15.9 ± 3.9, p = 0.0008, respectively), whereas no statistical difference was observed for GLS. In a subgroup analysis, GRS was significantly compromised in patients with a severely displaced tricuspid valve (>16 mm/m²) compared with milder forms (16.9 ± 8.3 vs. 21.5 ± 6.2, p = 0.03) and to controls (29.2 ± 9.5, p-value among the three groups <0.0001). Among EA patients with a preserved EF (RVEF > 52%), 12 (48%) versus 6 (24%) controls already showed compromised GRS and GCS.

Conclusion: The contractile pattern of the functional RV in EA is characterized by prevalent alterations in the short-axis direction as indicated by reduced GRS and GCS. Strain values might be reduced prior to routine used functional parameters like RVEF and can possibly serve as an early predictor of myocardial dysfunction in EA patients.

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Artikel online veröffentlicht:
12. Februar 2022