Natural history of echocardiographic changes in atrial fibrillation: A case-controlled study of longitudinal remodeling

BACKGROUND Atrial fibrillation (AF) can be a cause and consequence of cardiac remodeling. The natural history of remodeling associated with AF is incompletely described. OBJECTIVE The purpose of this study was to describe the frequency and timing of AF-associated echocardiographic changes. METHODS Patients within the Duke University Health System with >2 transthoracic echocardiograms (TTEs) performed between 2005 and 2018 were evaluated. Patients with AF and normal baseline TTEs were matched to patients without AF on year of TTE, age, and CHA2DS2-VASc score. Frequency and timing of changes in chamber size, ventricular function, mitral regurgitation, and all -cause mortality were compared over 5 years of follow-up. RESULTS The cohort included 3299 patients with AF at baseline and 7613 controls without AF. Normal baseline TTEs were acquired from 730 of patients with AF; 727 of these patients were matched to controls without AF. Patients with AF had higher rates of left atrial enlargement (hazard ratio [HR] 1.53; 95% confidence interval 1.27-1.85; P < .001), left ventricular (LV) systolic dysfunction (HR 1.80; 95% confidence interval 1.00-3.26; P = .045), LV diastolic dysfunction (HR 1.51; 95% confidence interval 1.08-2.10; P = .01), and moderate or greater mitral regurgitation (HR 2.09; 95% confidence interval 1.27-3.43; P = .003) than did controls. Atrial enlargement, systolic dysfunction, and mitral regurgitation surpassed the rates seen in controls within 6-12 months, whereas differences in diastolic dysfunction emerged at 24 months. There were no differences in ventricular sizes or mortality. CONCLUSION AF is associated with higher rates of left atrial enlargement, LV systolic and diastolic dysfunction, and mitral regurgitation that typically manifest within 6-24 months of diagnosis. The natural history of cardiac remodeling in patients with AF may inform treatment decisions and facilitate patient-tailored care.