Aims: The aim of this prospective study was to evaluate left atrial (LA) function for the prediction of increased risk of new-onset non-valvular atrial fibrillation (AF). Risk stratification for new-onset AF based on LA remodelling may have a major public health impact. Although left atrial volume (LAV) or LA dimension have been proposed as predictors of AF, other predictive parameters of LA function have not yet been fully examined.
Methods and results: LA emptying function (EF), strain rate (SR), and LAV were evaluated in the apical four-chamber view by speckle tracking echocardiography in 580 consecutive adults (age 64 ± 17, 303 men) without a history of atrial arrhythmias. During a follow-up period of 28 months, 32 subjects (age 73 ± 9, 18 men) developed electrocardiographically confirmed AF. Subjects with new-onset AF had lower LA active EF (16 ± 5 vs. 28 ± 8%, P< 0.001) and lower LA SR at atrial contraction (-0.9 ± 0.2 vs. -1.4 ± 0.5 S(-1), P< 0.001), but larger maximum LAV index (59 ± 12 vs. 46 ± 16 mL/m(2), P< 0.001) compared with non-AF subjects at baseline. In multivariate logistic regression analysis, LA active EF was the only independent predictor of new-onset AF. Using an LA active EF cut-off of ≤20%, the sensitivity and specificity for new-onset AF based on receiver operator characteristic curve analysis were 88 and 81%, respectively (area under the curve: 0.92).
Conclusion: Reduced LA active EF (booster pump function) assessed by speckle tracking echocardiography independently predicts the risk of new-onset AF, suggesting a stronger association between LA functional remodelling and AF than between LA size and AF.