Abstract Body (Do not enter title and authors here): Background: Left atrial (LA) functional remodeling plays an essential role in the pathophysiological mechanisms of atrial fibrillation (AF). LA reservoir strain (LARS) measured by speckle-tracking echocardiography (STE) exhibits acceptable predictive value for recurrent atrial arrhythmia in patients with paroxysmal AF, while its performance in persistent AF remains inconclusive. Recently, LA functional reserve, a novel concept of LA mechanics in response to acute-volume overload, is drawing attention.
Research Questions: Are LARS and LA functional reserve associated with recurrent atrial arrhythmia after catheter ablation in patients with persistent AF?
Methods: Ninety-two patients who underwent first catheter ablation for persistent AF were included in the study. LARS at rest and LA functional reserve were assessed by STE 1-4 days before catheter ablation. LA functional reserve was calculated as change in LARS after passive leg lifting. Recurrence of arrhythmia was defined as atrial arrhythmia of ≥ 30 seconds duration after a 2-month blanking period.
Results: The median values of LARS and LA functional reserve were 14.4 % (interquartile range [IQR] 10.9 to 18.2) and 1.0% (IQR -1.2 to 3.6), respectively. During a mean follow-up of 13.2 ± 9.9 months, 29 (31.5%) patients experienced recurrent AF. When we stratified patients into 2 groups according to LARS and LA functional reserve (below vs. above median values), patients with impaired LA functional reserve (< 1.0%) were at higher risk of AF recurrence (log-rank test p value=0.026), but this was not observed for LARS (Figure). In multivariable Cox proportional hazard analysis, impaired LA functional reserve was associated with recurrent atrial arrhythmia independent of AF risk factors, left ventricular ejection fraction and LARS at rest (adjusted hazard ratio 3.99, p=0.004).
Conclusions: Evaluation of LA functional reserve may provide valuable information for optimal patient selection as well as follow-up strategy after catheter ablation in patients with persistent AF.