Left atrial structure and function across the spectrum of cardiovascular risk in the elderly: The atherosclerosis risk in communities study

Background - Although left atrial (LA) enlargement is a recognized risk factor for adverse cardiovascular outcomes, emerging evidence supports the importance of LA function. We examined LA emptying fraction (LAEF) across the spectrum of cardiovascular disease burden in a large cohort of elderly adults living in the community. Methods and Results - We studied 1142 participants in the Atherosclerosis Risk in Communities (ARIC) study who were in sinus rhythm, free of valvular disease, and had acceptable quality 3-dimensional echocardiograms (mean age, 76±5 years; 59% women). We determined the cross-sectional correlates of LAEF and compared LAEF among elderly adults without cardiovascular disease or cardiovascular risk factors (n=201), those with hypertension (n=734), and those with overt heart failure (HF; n=207). In multivariable analysis, lower LAEF was associated with higher LA volumes and worse left ventricular systolic and diastolic functions. Elderly participants free of cardiovascular disease or risk factors had smaller LA volumes than those with hypertension (LA volume max/body surface area 30.2±6.6 versus 33.0±9.0 mL/m²; P=0.001), but similar LAEF (55.2±10.3% versus 53.8±11.5%, respectively; P=0.357). Participants with HF had higher LA volume (39.8±13.3 mL/m²) and worse LAEF (47.6±14.6%) than participants with hypertension or participants free of cardiovascular disease or risk factors (all P<0.001). Conclusions - In a community-based cohort, LA function was impaired in participants with prevalent HF, but there were no significant differences in LA function between participants with hypertension and those with free of cardiovascular disease or risk factors, despite greater LA size in the former.