Echocardiographic Predictors of Progression to Persistent or Permanent Atrial Fibrillation in Patients with Paroxysmal Atrial Fibrillation (E6P Study)

Abstract

Backgrounds: Paroxysmal atrial fibrillation (AF) frequently, but not always, progresses to persistent/permanent AF. The aim of this study was to evaluate the echocardiographic predictors of AF progression in patients with paroxysmal AF. Methods: A multicenter, prospective, observational study was conducted that included 313 patients with paroxysmal AF who underwent two-dimensional speckle-tracking echocardiography. The diameter, volume, and mechanical function of the left atrium, including global strain (epsilon) and epsilon rate, were measured. Results: Progression to persistent or permanent AF occurred in 52 patients (16.6%) during a median follow-up period of 26 months. Echocardiographic measure of left atrial (LA) diameter, volume, and function (E velocity, E/A and E/e' ratio, LA expansion index, active emptying fraction, global longitudinal epsilon and epsilon rate) were associated with AF progression. LA epsilon <= 30.9% was the strongest predictor of AF progression, which was associated with a more than fourfold hazard increase for AF progression (hazard ratio, 4.224; P =.001). LA diameter > 39 mm and maximal LA volume index > 34.2 mL/m(2) were associated with about a twofold hazard increase for AF progression (hazard ratios, 1.994 and 2.649; P = .016 and P =.001, respectively). When adjusted for a model combining maximal LA volume index, E velocity, LA expansion index, and active emptying fraction, LA epsilon <= 30.9% maintained a more than threefold hazard increase for AF progression (adjusted hazard ratio, 3.970; P =.003). Conclusions: Echocardiographic measures of LA diameter, volume, and mechanical function, including LA epsilon, were associated with AF progression. LA epsilon was the strongest independent predictor of AF progression and is expected to serve as a valuable predictor of AF progression.