Left atrial size and echocardiographic diastolic parameters as predictors of incident atrial fibrillation in older hospitalized patients

Background The associations between left atrial (LA) size, echocardiographic diastolic parameter (E/A ratio), and incident atrial fibrillation (AF) in older inpatients remain underexplored. Aims This study aimed to evaluate the relationship between LA size, E/A ratio, and AF risk in older hospitalized patients. Methods Between January 2015 and May 2023, a total of 2,615 older inpatients (aged ≥ 65 years) were enrolled in this retrospective longitudinal study. Left atrial diameter (LAD) and E/A ratio were measured using transthoracic echocardiography. Results Over a median follow-up of 844 days (IQR: 331–1355 days), 209 patients (8.0%) experienced at least one incident of AF. After adjusting for covariates, large LA and high E/A ratio were significantly associated with incident AF, with an 11% increase in risk for each 1 mm increase in LAD over 35 mm (adjusted HR: 1.11, 95% CI: 1.10–1.13) and a 30% increased risk per standard deviation increase in E/A ratio when E/A ratio exceeded 0.65 (adjusted HR: 1.30, 95% CI: 1.23–1.37), P < 0.001. The influence of LA size and E/A ratio on incident AF was more pronounced in the younger subgroup of older adults. Incorporating LAD and E/A ratios into the CHA2DS2-VASc score improved its predictive accuracy (AUC increase = 0.168, P < 0.001). Discussion This study shows that LA size and E/A ratio are key predictors of AF in hospitalized older patients, with age influencing their predictive value. Incorporating these factors into the CHA2DS2-VASc score enhances risk stratification and highlights the need for early AF screening in this group. Conclusions In hospitalized older patients, large LA and high E/A ratio are associated with incident AF, and these associations are more pronounced in younger individuals. LAD and E/A ratios provide incremental predictive value for AF beyond the CHA2DS2-VASc score. Graphical Abstract LA, left atrium; ASE: American Society of Echocardiography; E, mitral inflow velocity in the early diastolic phase; A, mitral inflow velocity in the late diastolic phase; AF: Atrial Fibrillation.