LA Phasic Volumes and Reservoir Function in the Elderly by Real-Time 3D Echocardiography: Normal Values, Prognostic Significance, and Clinical Correlates.

OBJECTIVES

This study sought to assess the prevalence and prognostic value of abnormalities in left atrial (LA) phasic volumes and reservoir function in a community cohort.

BACKGROUND

LA enlargement is associated with adverse cardiovascular outcomes. Real-time 3-dimensional (RT3D) echocardiography allows assessment of LA phasic volumes and reservoir function. However, there is a paucity of data regarding normal values, clinical correlates, and prognostic value of RT3D echocardiography-derived LA phasic volumes and reservoir function, especially in the elderly, a subgroup at high risk for cardiovascular events.

METHODS

Left atrial maximum volume (LAVi), minimum volume (LAVi), and reservoir function assessed as emptying volume (LAEV), emptying fraction (LAEF), and expansion index (LAEI), were measured by RT3D echocardiography in participants from a community-based cohort study. Cut-off values for LA phasic volumes were derived from a healthy subgroup of participants free of cardiovascular disease and risk factors (n = 142; 66 ± 9 years of age; 55% women). Annual follow-up examinations were performed for cardiovascular outcomes (myocardial infarction, ischemic stroke, and vascular death).

RESULTS

The cohort included 706 participants (71 ± 9 years of age; 59% women). LAVi and LAVi were not associated with age in the healthy subgroup but progressively increased with age in the entire cohort (p < 0.001). During a median follow-up of 7 years (minimum 0.06, maximum 9.5 years), 78 cardiovascular events occurred. In univariate analysis, LAVi, LAVi, and reservoir function parameters were significantly associated with outcome. In multivariate analysis, LAVi ≥20.5 ml/m (adjusted hazard ratio [aHR]: 1.79; 95% confidence interval [CI]:1.02 to 3.16) and LAEV ≤5.7 ml/m (aHR: 1.98; 95% CI: 1.02 to 3.85) remained significantly associated with events. LAVi and LA reservoir function showed incremental prognostic value over that of LAVi.

CONCLUSIONS

LA phasic volumes and reservoir functions assessed by RT3D echocardiography were strong independent predictors of cardiovascular events in a community-based elderly cohort. LAVi and reservoir function assessment may improve cardiovascular outcome prediction over LAVi.