The Value of the Newly Validated Cardiovascular Magnetic Resonance Derived Total Right/Left Volume Index in the Course of Ebstein Anomaly: A Prospective Long-Term Follow-up Study

Objectives: Classification of clinical severity of Ebstein anomaly (EA) remains a challenge. Recently, we proposed a simple CMR based index, the Total Right/Left Volume Index (ToRLVi) as a measure of disease severity in EA and reported its correlation with heart failure markers (1). The aim of the present investigation was to evaluate the consistency of the ToRLVi and its correlation with heart failure markers over time in a long term follow-up design.

Methods: This was a prospective long-term follow-up study. From the original cohort of 25 EA patients (1), 21 with unrepaired EA were available for the first follow-up at 3 years (mean follow-up: 35.6 ± 3.8 months; 1 death, 1 claustrophobic, 2 lost to follow-up) and completed the examinations. Disease severity was classified using CMR derived ToRLVi, volumes and functional measurements (RA, aRV, fRV and LV EF, EDVi, ESVi, PR) as described previously (1). CMR parameters were compared with heart failure markers including clinical data, ECG, laboratory, cardiopulmonary exercise testing (CPEX). Examinations were completed within 24 hours. Paired t-tests and multivariate regression to identify predictors of change in ToRLVi between baseline and follow-up were performed.

Results: The mean patient age was 28 ± 16 years. One patient with initial NYHA class IV and the highest ToRLVi in the original study cohort died. For the patients available for follow-up clinical status, heart failure markers and CMR parameters were largely unchanged between baseline and follow-up (Table 1). Patients were found to be in NYHA classes I and II, but no significant changes were seen with regard to heart failure markers. Thus, regression analysis could not identify any predictive markers of change in ToRLVi from ECG, CPEX (Qtc, O₂ pulse, VE/VCO_2, VO₂/kg max.) or laboratory (BNP) data in our cohort. There was no change in ToRLVi between baseline and follow-up (2013: 2.59 ± 1.31 and 2016: 2.60 ± 1.29). Correlations with heart failure parameters were preserved.

Conclusion: In this cohort of EA, the severity of disease and correlation with heart failure markers are well described by the ToRLVi. Stable values of the ToRLVi are indicative of insignificant progression in the disease severity and heart failure markers. A longer follow-up period is required to observe significant changes in the clinical status, and possibly ToRLVi in EA. 1) Hösch et al., Circ Cardiovasc Imaging. 2014;7:601–609

 

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No conflict of interest has been declared by the author(s).