Association of left atrial function with frailty: The Atherosclerosis Risk in Communities (ARIC) study

Background: Frailty is common in people with cardiovascular disease. Worse left atrial (LA) function is an independent risk factor for cardiovascular disease. However, whether worse LA function is associated with frailty is unclear. Methods: We included 3292 older adults from the Atherosclerosis Risk in Communities study who were non-frail at baseline (visit 5, 2011-2013) and had LA function (reservoir, conduit, and contractile strain) measured from two-dimensional speckle-tracking echocardiography. LA stiffness index was calculated as a ratio of E/e ' to LA reservoir strain. Frailty was defined using the validated Fried frailty phenotype. Incident frailty was assessed between 2016 and 2019 during two follow-up visits. LA function was analyzed as quintiles. Multivariable logistic regression examined odds of incident frailty. Results: Median (interquartile range [IQR]) age was 74 (71-77) years, 58% were female, and 214 (7%) participants developed frailty during a median (IQR) follow-up of 6.3 (5.6-6.8) years. After adjusting for baseline confounders and incident cardiovascular events during follow-up, the odds of developing frailty was 2.42 (1.26-4.66) times greater among participants in the lowest (vs highest) quintile of LA reservoir strain and 2.41 (1.11-5.22) times greater among those in the highest (vs lowest) quintile of LA stiffness index. Worse LA function was significantly associated with the development of exhaustion, but not the other components of the Fried frailty phenotype. Conclusions: Worse LA function is associated with higher incidence of frailty and exhaustion component independent of LA size and left ventricular function. Future studies are needed to elucidate the underlying mechanisms that drive the observed association.