Ventricular scar channel entrances identified by new wideband cardiac magnetic resonance sequence to guide ventricular tachycardia ablation in patients with cardiac defibrillators

Abstract

Aims Ventricular tachycardia (VT) substrate-based ablation has become a standard procedure. Electroanatomical mapping (EAM) detects scar tissue heterogeneity and define conduction channels (CCs) that are the ablation target. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is able to depict CCs and increase ablation success. Most patients undergoing VT ablation have an implantable cardioverter-defibrillator (ICD) that can cause image artefacts in LGE-CMR. Recently wideband (WB) LGE-CMR sequence has demonstrated to decrease these artefacts. The aim of this study is to analyse accuracy of WB-LGE-CMR in identifying the CC entrances. Methods and results Thirteen consecutive ICD-patients who underwent VT ablation after WB-LGE-CMR were included. Number and location of CC entrances in three-dimensional EAM and in WB-LGE-CMR reconstruction were compared. Concordance was compared with a historical cohort matched by cardiomyopathy, scar location, and age (26 patients) with LGE-CMR prior to ICD and VT ablation. In WB-CMR group, 101 and 93 CC entrances were identified in EAM and WB-LGE-CMR, respectively. In historical cohort, 179 CC entrances were identified in both EAM and LGE-CMR. The EAM/CMR concordance was 85.1% and 92.2% in the WB and historical group, respectively (P = 0.66). There were no differences in false-positive rate (CC entrances detected in CMR and absent in EAM: 7.5% vs 7.8% in WB vs. conventional CMR, P = 0.92) nor in false-negative rate (CC entrances present in EAM not detected in CMR: 14.9% vs.7.8% in WB vs. conventional CMR, P = 0.23). Epicardial CCs was predictor of poor CMR/EAM concordance (OR 2.15, P = 0.031). Conclusion Use of WB-LGE-CMR sequence in ICD-patients allows adequate VT substrate characterization to guide VT ablation with similar accuracy than conventional LGE-CMR in patients without an ICD.

Cardiac Magnetic Resonance for Ventricular Tachycardia Ablation and Risk Stratification

“…The use of wideband sequences can overcome this limitation by minimising device-related artefacts, making LGE-CMR imaging robust for myocardial characterisation under these conditions ( 32 – 34 ). A good correlation between wideband LGE-CMR and EAM has recently been demonstrated in previous work by our group ( 35 ).…”

Scar channels in cardiac magnetic resonance to predict appropriate therapies in primary prevention

“…All CMR studies were performed with a 3T MAGNETOM Trio scanner (Siemens Healthcare, Erlangen, Germany), and the images were processed with ADAS 3D software (ADAS3D Medical S.L., Barcelona, Spain) following a previously described protocol. [7][8][9] Briefly, 2 independent investigators analyzed the CMR images and a third observer was available in case of discrepancies. Full left ventricular volume was reconstructed in the axial orientation, and the resulting images were processed with ADAS3D software.…”

Ablation Lesion Assessment with MRI

“…[ 47 , 48 ] We and other centres are now successfully employing these sequences, enabling high image quality without hyperintensity artefacts, even in the proximity of implanted devices. [ 49 ]…”

“…The capability of LGE-MRI to accurately localise arrhythmogenic substrate in terms of scar border zone and slow conduction channels in a 3D fashion is meanwhile well-established; this is also true for patients with implanted cardiac devices when employing specific wideband MRI sequences. [ 4 , 49 , 56 , 57 , 73 – 75 ] However, the elimination of LGE-MRI-detected arrhythmogenic substrate as a potential endpoint of VT ablation has not been studied.…”