The degree of left atrial structural remodeling impacts left ventricular ejection fraction in patients with atrial fibrillation.
OBJECTIVE
The extent of left atrial (LA) wall structural remodeling (fibrosis) detected by late gadolinium enhancement-magnetic resonance imaging (LGE-MRI) is correlated with advanced atrial fibrillation (AF). The concomitant occurrence of AF and left ventricular (LV) dysfunction is not uncommon. We studied the effect of LA fibrosis, a confounder of both AF and LV dysfunction, on LV ejection fraction (EF).


METHODS
For the analysis, we identified and included 384 patients from our retrospective AF database who underwent LGE-MRI and transthoracic echocardiography prior to AF ablation. Based on the degree of LA fibrosis, patients were categorized into four stages as: Utah 1 (<5% LA fibrosis), Utah 2 (5-20% fibrosis), Utah 3 (20-35% fibrosis), and Utah 4 (>35% fibrosis).


RESULTS
The average pre-ablation LVEF was 60.5%±8.5% (n=24) in Utah stage 1 patients, 55.7%±10.3% (n=240) in Utah stage 2 patients, 51.7±11.5% (n=90) in Utah stage 3 patients, and 48.9%±11.6% (n=30) in Utah stage 4 patients (p<0.001, one-way ANOVA). The percentage of LA fibrosis was significantly negatively correlated to LVEF pre-ablation in a univariate analysis (p<0.001). In a multivariate model accounting for age, gender, AF type, and comorbidities such as diabetes and hypertension, Utah stage remained a significant predictor of pre-ablation EF (p<0.001).


CONCLUSIONS
Patients with extensive LA fibrosis appear to have depressed LV function pre-ablation, suggesting that structural remodeling in the LA may also be triggering and promoting remodeling within the ventricular myocardium.
University of Utah, Carma (Comprehensive Arrhythmia Research and Management) Center, Salt Lake City, Utah, USA. mehmetkky@yahoo.com.
Mehmet
M
Akkaya
University of Utah, Carma (Comprehensive Arrhythmia Research and Management) Center, Salt Lake City, Utah, USA.
Nassir
N
Marrouche
University of Utah, Carma (Comprehensive Arrhythmia Research and Management) Center, Salt Lake City, Utah, USA.
Koji
K
Higuchi
University of Utah, Carma (Comprehensive Arrhythmia Research and Management) Center, Salt Lake City, Utah, USA.
Matthias
M
Koopmann
University of Utah, Carma (Comprehensive Arrhythmia Research and Management) Center, Salt Lake City, Utah, USA.
Kavitha
K
Damal
University of Utah, Carma (Comprehensive Arrhythmia Research and Management) Center, Salt Lake City, Utah, USA.
Eugene
E
Kholmovski
University of Utah, Carma (Comprehensive Arrhythmia Research and Management) Center, Salt Lake City, Utah, USA.
Chris
C
McGann
D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000503:physiopathology*; D016279:Atrial Function, Left / Q000502:physiology; D064752:Atrial Remodeling / Q000502:physiology*; D005260:Female; D006346:Heart Septum / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology*