Usefulness of Left Atrial Reservoir Strain to Predict Long-Term Atrial Fibrillation Recurrence after Catheter Ablation

Objectives: The present study aims to assess the role of left atrial (LA) strain in predicting long-term atrial fibrillation (AF) recurrence in unselected patients undergoing catheter ablation (CA).Background. Modern echocardiographic techniques, as speckle-tracking, have allowed indirect assessment of LA fibrosis and remodeling. LA strain has been associated with AF recurrence following CA, however, its clinical applicability remains uncertain. Methods: Consecutive patients undergoing AF CA were enrolled. Recurrences were defined as AF episodes lasting >30 seconds, occurring after a 3-months blanking period following CA. LA reservoir (LASr), conduit (LAScd) and contractile strain (LASct) along with strain rates (respectively pLASr, pLAScd, pLASct) were assessed. Results: 47 patients were included in the analysis. Mean age was 61{plus minus}11 years, 9 (19%) females, 19 (40%) with persistent AF, 15 (32%) with ongoing AF. 10 (21%) patients underwent cryoballoon, while the remaining radiofrequency CA. During a mean follow-up of 24{plus minus}12 months, AF recurrence occurred in 18 (38%) patients. BMI, ongoing AF, LA area and indexed volume, emptying fraction, LASr, LASct, pLASr, pLAScd, and mechanical dispersion were all associated with AF recurrence. At multivariable Cox-regression analysis, only LASr remained independently associated with AF recurrence (OR 0.57 per 5%-increase, 95%CI 0.34-0.96). LASr {greater than or equal to} 24% related to lower 24-month (0% vs 49%, p=0.015) and 36-month (14% vs 67%, p=0.011) risk of recurrence, yielding a high diagnostic accuracy (AUC=0.74). Conclusions: LA strain emerges as an easily accessible, valuable diagnostic tool to be integrated in routine practice to improve pre-procedural identification of patients at higher risk of AF recurrence.