Cardiac MRI predictors of right ventricular dysfunction after the Da Silva cone operation for Ebstein's anomaly

Introduction: Despite the clinical benefits of the cone operation for Ebstein's anomaly, significant right ventricular (RV) dysfunction is frequently seen immediately after the procedure and if persistent may portend worse long-term outcomes. In this study we sought to evaluate the predictors of RV dysfunction after the cone operation using preoperative CMR.

Methods: This was a retrospective review of 26 consecutive patients who had the cone operation. Patients with significant RV dysfunction (RVD), defined as moderate or severe dysfunction by discharge echocardiogram, were compared to patients with no or mild dysfunction (no RVD).

Results: The median age at the operation was 12.2 years (interquartile range (IQR): 4.9-31.7 years). Eighteen patients (69%) had RVD. Patients with RVD had worse preoperative RV ejection fraction (36 ​± ​15 vs 49 ​± ​11%, p ​= ​0.02) and a larger cardiothoracic (CT) index (44 ​± ​8 vs 37 ​± ​6, p ​= ​0.03). The tricuspid valve was more severely abnormal in the RVD group with higher rotational angle (45 ​± ​17 vs 23 ​± ​10°, 0.03) and higher displacement index (39 ​± ​18 vs 23 ​± ​12%, p ​= ​0.02). RVD associated with a higher vasoactive inotropic score (P ​< ​0.01) and a trend towards a longer intensive care stay (p ​= ​0.07).

Conclusion: RVD is common after the cone operation and associated with higher need for postoperative inotropes. Predictors include lower preoperative RV ejection fraction, a more dilated heart and more severe tricuspid valve abnormality. Preoperative CMR is an important tool in preoperative assessment and helps predict RVD.