1354872 - Change in Right Ventricular Strain after Cone Reconstruction of Ebstein’s Anomaly: a CMR-FT Study

Ebstein’s Anomaly (EA) is a rare congenital heart disease characterized by apical displacement of the functional annulus of the tricuspid valve (TV). It is however considered a developmental disorder affecting the global right ventricular myocardium. Da Silva’s Cone repair is a novel surgical technique that for the first time has allowed an anatomical repair of the TV, with promising results. Several studies on right ventricular performance before and after Cone surgery have failed to identify a parameter that truly reflects pre- and postoperative myocardial function. CMR Feature Tracking (CMR-FT) is a well-established method to assess myocardial contraction with potential for diagnostic and prognostic value in many diseases. The aim of our study is to evaluate the potential of CMR-FT of the right ventricle (RV) in pre- and postoperative assessment of EA patients undergoing Cone repair.

Methods:

A total of 9 EA patients who had undergone Cone repair at our center between 2017 and 2021 and had a complete CMR evaluation before and after surgery, were selected retrospectively. CMR-FT Analysis was performed in each patient pre- and postoperatively at a dedicated workstation (Circle Cardiovascular Imaging Inc., CVI42® 5.12.1 software, Calgary, Alberta) by manually tracing the endo- and epicardial contours of the functional RV on steady-state-free-precession cine images. Short-axis cine images (basal, mid, apical) were used to generate global radial (GRS) and global circumferential strain (GCS). Global longitudinal strain (GLS) was obtained from a four-chamber cine image. Statistical analysis was performed using GraphPad Prism software (GraphPad Prism® version 9.2.0, GraphPad Software Inc., La Jolla, CA).

Results:

We evaluated 9 patients (5 female, 4 male) with a median age of 26 (rage 11-40) at first CMR. Postoperative CMR was at median 12 months (range 10-18) after Cone repair. RV ejection fraction decreased from median 55% (range 28-61%) to 36% (range 22-42%) after repair. GLS deteriorated in 8 out of 9 patients, without reaching a significant result (-19.95% vs. -15.20%, p = 0.0907). No relevant difference was observed in GRS (15.43% vs. 17.83%, p = 0.4225) and GCS (9.97% vs. -12.41%, p = 0.2864), with a slight trend towards improvement.

Conclusion:

RV-FT parameters did not show any remarkable impact after Cone repair. Similar to conventional CMR parameters like RVEF, GLS appears to be load dependent, as indicated by slight postoperative impairment. Reduced afterload due to TV regurgitation may cause “false” normal values preoperatively. Since GRS and GCS did not change, we assume that short-axis strain might be less confounded by altered loading conditions and thus might provide diagnostic value.