Predicting Biventricular Repair in Common Atrioventricular Canal by Cardiac Magnetic Resonance Imaging: The New Normal?

Introduction: Patients with malaligned common atrioventricular (AV) canal (CAVC) are difficult to manage when one ventricle is borderline hypoplastic. The decision between the single ventricle pathway or attempting a biventricular repair depends upon pre-operative parameters which have previously been studied only by echocardiography. The purpose of this study was to determine the utility of cardiac magnetic resonance (CMR) in predicting success of a biventricular repair in CAVC. Methods: We performed a single center, retrospective cohort study of children with varying degrees of CAVC malalignment who underwent CMR prior to definitive repair (7/1/10 to 2/28/21). The primary outcome was successful biventricular repair. CMR measurements were performed by the investigators. To account for both dominant right ventricles (RV) and left ventricles (LV), ratios of ventricular and AV valve size were normalized as differences from their expected values. Associations were tested using univariable logistic regression. Multivariable regression models using combinations of two variables with p-values less than 0.2 were tested. Results: We included 28 patients (median age at CMR: 5.2 months, 43% male). Clinical and CMR variables are shown in Table 1. The optimal multivariable predictive model included the normalized LV end diastolic volume (EDV) to total ventricular EDV ratio and the LV-RV angle in diastole. Area under the receiver operator characteristic curve was 0.83 (p = 0.041). An LV EDV to total EDV ratio between 0.30 and 0.66 had a sensitivity of 92% and specificity of 63% for predicting successful biventricular repair. Including an LV-RV angle in diastole of less than 72 degrees resulted in a sensitivity of 83% and specificity of 81%. Conclusions: Multiple CMR measures were associated with surgical outcomes. CMR measures such as LV EDV to total ventricular EDV ratio and LV-RV angle in diastole can accurately predict successful biventricular canal repair.