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

Abstract

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.

Keywords: Atrial fibrillation; Cardiac remodeling; Case-control; Clinical outcomes; Echocardiography.