Left Atrial Strain for Predicting Atrial Fibrillation Recurrence After Catheter Ablation

Abstract

Introduction: Recurrence of atrial fibrillation (AF) after catheter ablation remains high (20–40%). Conventional predictors (left atrial volume, AF type) have modest accuracy. Left atrial reservoir strain (LARS) measured by speckle-tracking echocardiography may be a superior predictor.
Methods: Systematic review and meta-analysis of observational studies and post-hoc trial analyses. Inclusion: patients undergoing first AF ablation (paroxysmal or persistent), pre-procedural LARS measured, follow-up ≥12 months with rhythm monitoring. Exclusion: prior ablation or structural heart disease. Outcome: any atrial arrhythmia recurrence.
Results: 23 studies (n=4,918 patients) with mean LARS 23.4% (SD 8.1). Optimal cutoff for predicting recurrence ranged 18–22%. Pooled sensitivity 71% (95%CI 67–75%), specificity 74% (70–78%). Lower LARS (per 5% absolute decrease) was associated with a 2.1-fold higher recurrence odds (OR 2.12, 1.76–2.56). LARS outperformed left atrial volume index (C-statistic 0.72 vs. 0.62, p<0.01). Predictive value was stronger in persistent AF (OR 2.8) than paroxysmal (OR 1.7).
Discussion: LARS reflects atrial fibrosis and compliance beyond structural remodeling. Limitations include vendor-dependent strain algorithms, lack of standardization in acquisition (apical 4-chamber vs. 2-chamber), and heterogeneity in recurrence definitions (ECG vs. Holter).
Conclusions: Reduced left atrial reservoir strain is a robust predictor of AF recurrence after catheter ablation, with acceptable discriminative ability. LARS should be incorporated into pre-ablation risk stratification, though technical standardization is needed.