Cardiac magnetic resonance to predict recurrences after ventricular tachycardia ablation: septal involvement, transmural channels, and left ventricular mass

Abstract

Aims Ventricular tachycardia (VT) substrate-based ablation has an increasing role in patients with structural heart disease-related VT. VT is linked to re-entry in relation to myocardial scarring with areas of conduction block (core scar) and areas of slow conduction [border zone (BZ)]. VT substrate can be analysed by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Our study aims to analyse the role of LGE-CMR in identifying predictors of VT recurrence after ablation. Methods and results We analysed 110 consecutive patients who underwent VT ablation from 2013 to 2018. All patients underwent a preprocedural LGE-CMR, and in 94 patients (85.5%), the CMR was used to aid the ablation. All LGE-CMR images were semi-automatically processed using dedicated software to detect scarring and conducting channels. After a median follow-up of 2.7 ± 1.6 years, the overall VT recurrence was 41.8% with an implantable cardioverter-defibrillator shock reduction from 43.6% to 28.2% before and after ablation, respectively. The amount of BZ (26.6 ± 13.9 vs. 19.6 ± 9.7 g, P = 0.012), the total amount of scarring (37.1 ± 18.2 vs. 29 ± 16.3 g, P = 0,033), and left ventricular (LV) mass (168.3 ± 53.3 vs. 152.3 ± 46.4 g, P < 0.001) were associated with VT recurrence. LGE septal distribution [62.5% vs. 37.8%; hazard ratio (HR) 1.67 (1.02–3.93), P = 0.044], channels with transmural path [66.7% vs. 31.4%, HR 3.25 (1.70–6.23), P < 0.001], and midmural channels [54.3% vs. 27.6%, HR 2.49 (1.21–5.13), P = 0.013] were related with VT recurrence. Multivariate analysis showed that the presence of septal LGE [HR 3.67 (1.60–8.38), P = 0.002], transmural channels [HR 2.32 (1.15–4.72), P = 0.019], and LV mass [HR 1.01 (1.005–1.019), P = 0.002] were independent predictors of VT recurrence. Conclusion Pre-procedural LGE-CMR is a helpful and feasible technique to identify patients with high risk of VT recurrence after ablation. LV mass, septal LGE distribution, and transmural channels were predictive factors of post-ablation VT recurrence.

Analysis of Three-Dimensional Scar Architecture and Conducting Channels by High-Resolution Contrast-Enhanced Cardiac Magnetic Resonance Imaging in Chagas Heart Disease

“…BZ channel mass was an independent predictor of sustained VT in a retrospective case-control study among postmyocardial infarction patients 12 . Transmural BZ channels were also an independent predictor of post-ablation VT recurrence 13 . Furthermore, in ischemic and non-ischemic patients with left ventricular (LV) systolic dysfunction, BZ mass, and BZ channel mass were the strongest predictors of appropriate defibrillator therapy or sudden cardiac death 14 .…”

Cardiac Magnetic Resonance for Ventricular Tachycardia Ablation and Risk Stratification

“…Pre-procedural LGE-CMR is gaining widespread applicability as an assistance tool in ablation procedures because it can facilitate procedural planning, scar mapping, and ablation ( 28 – 30 ), as well as the evaluation of the risk of recurrences after ablation ( 31 ).…”

“…Pre-procedural CMR has already been proven to be related to recurrence rate. Quinto et al ( 31 ) analysed 110 consecutive patients who underwent VT ablation with pre-procedural LGE-CMR, and several factors identified by CMR were clearly related with a higher recurrence rate: BZ and total scar mass, transmural and midmural channels, and septal substrate ( Figure 3 ). In a previous smaller study ( 37 ), scar area was also related with VT recurrence, and a more recent study ( 38 ) including patients with NICM (25 patients) also confirmed that septal LGE extension was related to a higher VT recurrence rate.…”

“… Adapted from Quinto et al ( 31 ). Upper panel: Example of transmural channel in pixel signal intensity (PSI) map of three-dimensional late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR) reconstruction of the left ventricle.…”

“…This review article has used images from very important manuscripts in the field. This review wants to acknowledge the authors of these manuscripts [Andreu et al ( 29 ), Quinto et al ( 31 ), and Sanchez-Somonte et al ( 54 )] for their explicit permission to use the images that contributed to this review.…”