Anatomical severity of Ebstein's anomaly: a quantitative analysis based on cardiovascular MRI

Ebstein's anomaly (EA) exhibits significant anatomical and clinical heterogeneity, warranting a systematic approach to risk stratification. While the Carpentier classification (CC) is commonly employed for qualitative disease assessment, there is increasing interest in quantitative imaging parameters to personalise monitoring strategies and therapeutic interventions. We sought to evaluate the association between cardiovascular magnetic resonance (CMR) parameters, CC and symptoms of heart failure (HF). Also, we investigated whether CMR-derived markers may predict the need for bidirectional cavopulmonary anastomosis (BCPA) and the occurrence of haemodynamic complications or significant right ventricular (RV) dysfunction in the postoperative stay.

This retrospective study evaluated consecutive patients diagnosed with EA undergoing 1.5T CMR acquisition at a tertiary care centre. CC and quantitative indices were extracted from steady-state free precession sequences.

In a total population of 60 patients (53% male, median age 22 years), CMR parameters most strongly associated (p<0.001) with CC included indexed displacement of the septal (SLDi) and inferior (ILDi) leaflets, Ebstein valve rotation angle, functional RV ejection fraction, indexed atrialised RV end-diastolic volume and the ratio of either atrialised or functional RV to anatomical RV. Decreasing left ventricular ejection fraction (OR 0.85, 95% CI 0.75 to 0.97, p=0.01) and increasing ILDi (OR 1.05, 95% CI 1.00 to 1.10, p=0.04) emerged as the most prominent variables associated with HF symptoms. Additionally, ILDi was significantly linked to the need for BCPA (OR 1.15, 95% CI 1.03 to 1.28), the occurrence of haemodynamic complications (OR 1.09, 95% CI 1.01 to 1.18) and significant RV dysfunction in the postoperative stay (OR 1.08, 95% CI 1.01 to 1.17).

Quantitative CMR indices proved to be effective in distinguishing between Carpentier classes and they may be valuable in an integrated CMR-based approach to assess EA severity. Among these, ILDi reflects both the extent of tricuspid valve abnormality and RV atrialisation and may serve as a useful metric in guiding personalised therapeutic strategies.