Phasic left atrial strain predicts arrhythmia recurrence after atrial fibrillation ablation

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Global left atrial (LA) strain is a predictor of atrial fibrillation (AF) recurrence after radiofrequency pulmonary vein isolation (RF-PVI). However, little is known about phasic LA strain (i.e. LA reservoir strain, LA conduit strain, and LA contractile strain) and arrhythmia recurrence after AF ablative therapy. Aim This study was conducted to evaluate the impact of phasic LA longitudinal strain on arrhythmia recurrence after catheter ablation. Methods A total of 62 AF patients (77% paroxysmal AF, 66% male, mean age 61 ± 7 years) undergoing initial RF-PVI were included in the present analysis. Prior to AF ablation, all patients underwent cardiac magnetic resonance imaging in sinus rhythm. LA reservoir strain, conduit strain and contractile strain were derived from 2-chamber and 4-chamber cine CMR images using feature tracking. All patients were routinely followed up for arrhythmia recurrence through ECGs, Kardia or Holter monitoring. Results One year follow-up was incomplete in nine AF patients. Arrhythmia recurrence after the 90-day blanking period was observed in 20 patients (38%), occurring after a median of 159 (119-291) days. Significantly lower LA reservoir strain and LA contractile strain values were found in AF patients with arrhythmia recurrence after RF-PVI, as compared to AF patients without arrhythmia recurrence (-12.8 ± 4.1% vs. -15.6 ± 3.5%, P = 0.02, -5.4 ± 2.2% vs. -7.7 ± 2.3% P < 0.001, respectively). LA conduit strain did not differ between these two groups (-7.4 ± 2.7% vs. -7.9 ± 2.9%, P = 0.53). Arrhythmia-free survival was assessed using the Kaplan Meier method and compared between strain values below and above the median using the log-rank test (median LA reservoir strain: -13.45%, median LA conduit strain: -7.55%, median LA contractile strain: -5.60%). Arrhythmia-free survival was different between AF patients with a high and low LA reservoir strain, and between patients with a high and low LA contractile strain (P = 0.03 and P = 0.006, respectively). Conclusion Low LA reservoir strain and low LA contractile strain both are predictive for arrhythmia recurrence after RF-PVI. LA conduit strain did not differ between patients with and without arrhythmia recurrence. LA contractile strain had the highest predictive value and may be a valuable clinical marker to predict success of AF ablative therapy.