Left Ventricular Extracellular Volume Expansion does not Predict Recurrence of Atrial Fibrillation following Catheter Ablation

Abstract

Introduction:

A recent study reported diffuse left ventricular (LV) fibrosis is a predictor of atrial fibrillation (AF) recurrence following catheter ablation, by measuring post-contrast cardiac T ₁ (an error prone metric as per the 2017 SCMR consensus statement) using an inversion-recovery pulse sequence (an error prone method in arrhythmia) in AF ablation candidates. The purpose of this study was to verify the prior study, by measuring extracellular volume fraction (ECV) (an accurate metric) using a saturation-recovery pulse sequence (accurate method in arrhythmia).

Methods and Results:

This study examined 100 AF patients (mean age=62±11 years, 69 males and 31 females, 67 paroxysmal [pAF] and 33 persistent [peAF]) who underwent a pre-ablation cardiovascular magnetic resonance (CMR). LV ECV and LA and LV functional parameters were quantified using standard analysis methods. During an average follow-up period of 457±261 days with 4±3 rhythm checks per patient, 72 patients maintained sinus rhythm. Between those who maintained sinus rhythm (n=72) and those who reverted to AF (n=28), the only clinical characteristic that was significantly different was age (60 ± 12 years vs.66 ± 9 years); for CMR metrics, neither mean LV ECV (25.1 ± 3.3% vs. 24.7±3.7%), native LV T1 (1093.8 ± 73.5 ms vs. 1070.2 ± 115.9 ms), LVEF (54.1 ± 11.2% vs. 55.7±7.1%), or LA EDV/BSA (42.4 ± 14.8 mL/m ² vs. 43.4±19.6 mL/m ²) was not significantly different (p ≥ 0.23). According to Cox regression tests, none of the clinical and imaging variables predicts AF recurrence.

Conclusion:

Neither LV ECV nor other CMR metrics predict recurrence of AF following catheter ablation.