Impact of Congenital Substrate 3D Imaging Reconstruction to Guide VT Catheter Ablation: The CORECA Study

In the presence of sustained monomorphic ventricular tachycardia (VT), catheter ablation may be an option in congenital heart disease. However, the heterogeneity of underlying congenital heart disease and previous cardiac surgeries is associated with a unique and particularly complex substrate. The aim of the study was to investigate whether preprocedural 3-dimensional anatomic and substrate reconstruction based on cardiac computed tomography scan or magnetic resonance imaging could reliably identify VT substrate and ablation targets.

Consecutive patients with cardiac computed tomography or magnetic resonance imaging referred for VT ablation in 5 congenital electrophysiology centers were included. Three observers, electrophysiologists, blinded to the ablation procedure and each other, annotated potential ablation targets on 3-dimensional imaging reconstructions with a dedicated software (InHeart). Once completed, the annotations were compared between observers and with the ablation target(s) on the electroanatomical mapping generated during the procedures.

Forty patients (mean age, 38±12 years; 67.5% male) underwent VT ablation, including 28 with a history of spontaneous sustained VT. VT was inducible in 97.5% of cases, with an acute success rate of ablation of 92.5%. Preprocedural imaging identified VT substrate in concordance with electroanatomical mapping in 87.5% of cases. There was a high degree of agreement between the observers. Positive interobserver agreement was complete in 65.0% of cases, moderate in 22.5%, and poor in 5.0%. Considering the total number of isthmuses identified by imaging in comparison with electroanatomical mapping, the sensitivity of imaging was 87.0%, and its positive predictive value was 77.0%.

In our series, 3-dimensional anatomic reconstruction enabled identification of the critical VT substrate in most patients with complex congenital heart disease, particularly those with anatomically based reentrant circuits. Substrate target can be identified by operators with good interobserver reproducibility. This approach may guide VT ablation in these challenging cases.