Association of left atrial metrics with atrial fibrillation rehospitalization and adverse cardiovascular outcomes in patients with nonvalvular atrial fibrillation following index hospitalization

Background: Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice, with significant clinical and economic burdens, largely driven by adverse cardiovascular outcomes and AF-related hospitalization. Left atrial (LA) parameters have been shown to have prognostic value in cardiovascular disease states. We sought to evaluate the prognostic value of measures of LA size and function, as measured through LA volume index and LA emptying fraction (LAEF), respectively, for AF rehospitalization and long-term adverse outcomes in patients with nonvalvular AF following index hospitalization. Methods: In this retrospective study, 594 consecutive patients (mean age, 67.8 ± 13.6 years, 53% men) admitted to a tertiary referral center with nonvalvular AF were assessed. Patients who underwent transthoracic echocardiography during their index admission and had complete follow-up data were included and followed for a mean period of 33.18 ± 21.27 months for the primary outcome of AF rehospitalization. The secondary outcome was a composite of all-cause death and major adverse cardiovascular events. Results: The primary outcome occurred in 250 (42%) patients, and the secondary outcome occurred in 219 (37%) patients. On multivariable regression analysis, LAEF had an independent association with AF rehospitalization (hazard ratio [HR] = 0.967; 95% CI, 0.953-0.982; P <.01), and time-dependent receiver operating characteristic curves demonstrated LAEF to have strong diagnostic accuracy in predicting early and intermediate AF rehospitalization. Both LA volume index (HR = 1.014; 95% CI, 1.003-1.026; P =.01) and LAEF (HR = 0.982; 95% CI, 0.970-0.993; P <.01) were associated with all-cause death and major adverse cardiovascular events. Conclusions: Adverse LA remodeling, as reflected through LA enlargement and reduced LA mechanical function, is associated with AF rehospitalization and long-term adverse cardiovascular outcomes in hospitalized patients with nonvalvular AF.