Global atrial longitudinal strain is a powerful predictor of atrial fibrillation ablation outcomes in patients with normal echocardiographic images.

Background: Speckle tracking echocardiography (STE) with recent standardized left atrial (LA) deformation allows for the assessment of various LA function parameters. Proper qualification for catheter ablation (CA) for atrial fibrillation (AF) is still an issue. We aimed to assess the value of detailed evaluations of LA function parameters in patients without abnormal baseline standard echocardiography to predict the outcomes after CA for AF.Methods: We studied 84 patients (59% males, mean age 57.3±9.4 years) with nonvalvular paroxysmal AF who underwent CA and had normal preprocedural echocardiographic examinations. Peak longitudinal LA strain (LAS) and strain rate (LASR) during the reservoir (r), conduit (cd) and contraction (ct) phases were measured by STE. AF recurrence was confirmed by serial 4-7 day Holter ECG monitoring during a 12-month follow-up period. Three definitions of ablation success were used: complete success – freedom from symptomatic and asymptomatic AF without antiarrhythmic drug therapy (AA), success on AA – freedom from any AF with continued AA and partial success – clinically relevant reduction of the symptoms. The remaining patients were classified as having ablation failure.Results: Complete success was achieved in 37 (45.1%) patients, success on AA in 7 (8.5%) patients, and partial success in 11 (13.4%) patients. Altogether, 55 (67.1%) patients benefited from CA. The remaining 27 (32.9%) patients were classified as having CA failure. In the multivariate logistic regression analysis, only global LASr was identified as an independent predictor of AF recurrence after CA (OR [95% CI]: 1.27 [1.136-1.423], p<0.0001). The receiver operating characteristic analysis identified LASr as a powerful parameter for predicting the outcome after CA with an area under the curve (AUC) of 0.8548. When CA success was defined as all patients who benefited from CA, the multivariate logistic regression analysis also showed that only global LASr was an independent predictor of whether patients would benefit from CA (OR [95% CI]: 1.44 [1.207-1.716], p<0.0001)Conclusions: In patients with paroxysmal AF and normal standard echocardiographic assessments, LA strain analysis is crucial for selecting the best candidates for catheter ablation. LA reservoir strain is the only echocardiographic parameter that is an independent predictor of either complete success or clinical benefits from catheter ablation.