Comparison of Left Atrial Feature Tracking Strain and Rapid Long Axis Strain for Predicting Arrhythmia Recurrence After Atrial Fibrillation Ablation

Introduction: Global left atrial (LA) strain is a predictor of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). Recently, novel rapid LA long axis strain has been introduced. Currently, it is unknown whether this fast and simple strain approach can predict AF recurrence after PVI and hence may be a simple alternative for the cumbersome LA feature tracking (FT) strain analysis. Hypothesis: Rapid LA strain is a fast and simple alternative for predicting AF recurrence after PVI as compared to LA FT strain. Methods: A total of 58 AF patients (78% paroxysmal AF, 64% male, mean age 61±7 years) undergoing first PVI ablation were included. Prior to PVI, all patients were in sinus rhythm during cardiac magnetic resonance imaging. LA rapid strain, LA FT strain and LA volumes were derived from 2-chamber and 4-chamber cine CMR images (Figure A). All patients were routinely followed up for arrhythmia recurrence. Results: At one year follow-up, arrhythmia recurrence was observed in 21 patients (36%). Both, rapid LA strain and FT strain were significantly reduced in patients with AF recurrence compared to patients without AF recurrence (rapid strain: -19.96 ± 11.03% vs. -28.18 ± 9.93%, P=0.005; FT strain: -12.54 ± 4.16% vs. -15.94 ± 3.50%, P=0.002, Figure B, and C) while maximal LA volume index (LAVImax) was not different between both groups (16.98 ± 3.70ml/m2 vs. 15.04 ± 2.47ml/m2, P=0.11, Figure D). ROC analysis identified LA FT strain as having the highest area under the curve (AUC) for predicting AF recurrence after PVI (AUC: 0.75 for LA FT strain, 0.71 for LA rapid strain, 0.62 for LAVImax, figure E). Conclusions: Both rapid LA strain and LA FT strain are predictive of AF recurrence after index PVI in AF patients. Moreover, LA mechanical function (strain) may be a more useful marker for predicting AF recurrence than LA volume. Therefore, LA rapid strain can be a more convenient and reproducible parameter for the assessment of LA performance in clinical practice.