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. Objectives Describe the frequency and timing of AF-associated echocardiographic changes. Methods Patients within the Duke University Health System with two or more transthoracic echocardiograms (TTEs) performed between 2005-2018 were evaluated. AF patients with 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 five years of follow-up. Results The cohort included 3,299 patients with AF at baseline and 7,613 controls without AF. Normal baseline TTEs were seen in 730 of the AF patients; 727 of these patients were matched to controls without AF. AF patients had higher rates of LA enlargement (HR 1.53 [1.27-1.85], p<0.001), LV systolic dysfunction (HR 1.80 [1.00-3.26], p=0.045), LV diastolic dysfunction (HR 1.51 [1.08-2.10], p=0.01) and moderate or greater mitral regurgitation (HR 2.09 [1.27-3.43], p=0.003) compared to controls. Atrial enlargement, systolic dysfunction, and mitral regurgitation surpassed the rates seen in the controls within 6-12 months; whereas, differences in diastolic dysfunction emerged at 24 months. There were no differences in ventricular sizes or mortality. Conclusions AF is associated with higher rates of LA 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 AF patients may inform treatment decisions and facilitate patient-tailored care. Atrial fibrillation (AF) can be a cause and consequence of cardiac remodeling. The natural history of remodeling associated with AF is incompletely described. Describe the frequency and timing of AF-associated echocardiographic changes. Patients within the Duke University Health System with two or more transthoracic echocardiograms (TTEs) performed between 2005-2018 were evaluated. AF patients with 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 five years of follow-up. The cohort included 3,299 patients with AF at baseline and 7,613 controls without AF. Normal baseline TTEs were seen in 730 of the AF patients; 727 of these patients were matched to controls without AF. AF patients had higher rates of LA enlargement (HR 1.53 [1.27-1.85], p<0.001), LV systolic dysfunction (HR 1.80 [1.00-3.26], p=0.045), LV diastolic dysfunction (HR 1.51 [1.08-2.10], p=0.01) and moderate or greater mitral regurgitation (HR 2.09 [1.27-3.43], p=0.003) compared to controls. Atrial enlargement, systolic dysfunction, and mitral regurgitation surpassed the rates seen in the controls within 6-12 months; whereas, differences in diastolic dysfunction emerged at 24 months. There were no differences in ventricular sizes or mortality. AF is associated with higher rates of LA 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 AF patients may inform treatment decisions and facilitate patient-tailored care.