Association of left atrial structure and function with cognitive function among adults with metabolic syndrome

Background: Atrial fibrillation has been associated with cognitive impairment. Whether subclinical abnormalities in atrial function and substrate predisposing to atrial fibrillation impact cognitive function has received limited attention. Methods: We tested associations of echocardiographic markers of atrial structure and function with cognitive functioning and decline among 510 participants with overweight/obesity and metabolic syndrome (mean age [standard deviation] of 64.4 [5.2] years in men and 66.5 [3.9] in women). Left atrial markers (volume index, emptying fraction, strain, function index, and stiffness index) were estimated based on transthoracic echocardiography. General cognitive functioning (Mini-mental examination), verbal ability (verbal fluency test), memory and attention (Digit Span Tests), and processing speed and executive function (Trail-Making Tests A and B) were assessed at baseline and at the two-year follow-up. Multiple linear regression was used to test associations of atrial markers (modeled in standard deviation units) with baseline and two-year changes in cognitive scores adjusting for demographic and health covariates. Results: Left atrial structure and function was not associated with cognitive function at baseline. Larger left atrial volume index (standardized {beta} [95% confidence interval] = -0.13 [-0.22, -0.03]), lower peak longitudinal strain (-0.11 [-0.20, -0.01]), and higher stiffness index (-0.18 [-0.28, -0.08) were associated with 2-year worsening in Trail-Making Test A. Strain measurements were also associated with 2-year change in the Controlled Oral Word Association Test. Conclusion: Overall, adverse markers of left atrial structure and function were associated with 2-year detrimental executive function-related cognitive changes in a sample of participants at high risk for cardiovascular disease, highlighting left atrial substrate as a potential risk factor for cognitive decline and dementia.