Comparison of various late gadolinium enhancement magnetic resonance imaging methods with high-definition voltage and activation mapping for detection of atrial cardiomyopathy

Abstract

Aims Atrial cardiomyopathy (ACM) is associated with increased arrhythmia recurrence rates after pulmonary vein isolation (PVI). We compare the most common left atrial (LA) late gadolinium enhancement magnetic resonance imaging (LGE-MRI)-methods [Utah-method and image intensity ratio (IIR)-methods] and endocardial voltage mapping for ACM-detection and outcome prediction after PVI for atrial fibrillation (AF). Methods and results In this prospective observational study, 37 ablation-naive patients (66 ± 9 years, 84% male) with persistent AF underwent LA-LGE-MRI and high-definition voltage and activation mapping (2129 ± 484 sites) in sinus rhythm prior to PVI. The MRI-post-processing-analyses were performed by two independent expert laboratories. Arrhythmia recurrence was recorded within 12 months following PVI. The global ACM-extent was highly variable: median LA low-voltage substrate (LA-LVS) was 12.9% at <1.0 mV and 2.7% at <0.5 mV; median LA-LGE-extent using the Utah-method was 18.3% and 0.03–93.1% using the IIR-methods. The LA activation time was significantly correlated with LA-LVS (r = 0.76 at <0.5 mV and r = 0.82 at <1.0 mV, both P < 0.0001), but not with LA-LGE-extent. The highest regional matching between LA-LVS <0.5 mV and LA-LGE was found for the anterior wall in 57% of patients using the Utah-method and in 59% using IIR 1.20. The corresponding values for the posterior wall were 19% and 38%, respectively. Arrhythmia recurrence occurred in 15(41%) patients. Freedom from arrhythmia was significantly lower in those with LA-LVS ≥2 cm2 at 0.5 mV but not in those with LGE ≥20% (Utah-stages III and IV): 43% vs. 81%, P = 0.009 and 50% vs. 67%, P = 0.338, respectively. Conclusion Comparison of the most common LA-LGE-MRI methods and endocardial voltage mapping revealed large discrepancies in global and regional ACM-extent.

Atrial cardiomyopathy: from cell to bedside

“…It has been regarded as the gold standard in determining atrial abnormality. Low‐voltage areas detected by electroanatomic mapping systems are a powerful predictor of atrial remodelling and poor prognosis post‐ablation 104,105 . But as an invasive procedure, electroanatomic mapping cannot be used for preprocedural and prognostic evaluation.…”

“…Low-voltage areas detected by electroanatomic mapping systems are a powerful predictor of atrial remodelling and poor prognosis post-ablation. 104,105 But as an invasive procedure, electroanatomic mapping cannot be used for preprocedural and prognostic evaluation. A recent study revealed that there existed large discrepancies in identifying both extent and regional distribution of ACM between the most common LGE-CMR methods and endocardial mapping.…”

“…A recent study revealed that there existed large discrepancies in identifying both extent and regional distribution of ACM between the most common LGE‐CMR methods and endocardial mapping. Thus, optimizing the ACM‐detection methods of LGE‐CMR is required 105 …”

Role of advanced imaging with cardiac computed tomography and MRI in atrial and ventricular ablation

“…Both CMR and CCT require administration of contrast to delineate areas of myocardial scar, which can be problematic in selected patients with impaired renal function [64]. Consensus on the ideal method for quantifying myocardial scar on CMR or CCT is lacking [65,66], with histologic data suggesting significant variability in the extent of myocardial scar and border zone areas depending on the methodology used for delineating fibrosis [67]. Lastly, volume changes and misalignment between CMR/CCTderived image mesh and EAM can lead to co-registration errors [68], limiting accuracy for the purpose targeting sites for ablation.…”

New concepts in atrial fibrillation pathophysiology

“…However, it is currently not possible to differentiate between LGE areas caused by replacement fibrosis, necrosis, inflammation, edema, or interference with adjacent hyperenhanced structures, such as epicardial fat. Additionally, different LGE-MRI postprocessing methods lead to discrepancies regarding extent and regional distribution of atrial cardiomyopathy, as well as the correlation to low-voltage assessed in endocardial voltage mapping [10]. The contrasting results may be related to technical challenges with LGE-MRI, including spatial resolution, motion artifact, irregular heart rates, and the quantitation of LGE, which can be algorithm-dependent.…”