Progression of atrial remodeling in patients with high-burden atrial fibrillation: Implications for early ablative intervention.
BACKGROUND
Advanced atrial remodeling predicts poor clinical outcomes in human atrial fibrillation (AF).


OBJECTIVE
The purpose of this study was to define the magnitude and predictors of change in left atrial (LA) structural remodeling over 12 months of AF.


METHODS
Thirty-eight patients with paroxysmal AF managed medically (group 1), 20 undergoing AF ablation (group 2), and 25 control patients with no AF history (group 3) prospectively underwent echocardiographic assessment of strain variables of LA reservoir function at baseline and at 4, 8, and 12 months. In addition, P-wave duration (Pmax,, Pmean) and dispersion (Pdis) were measured. AF burden was quantified by implanted recorders. Twenty patients undergoing ablation underwent electroanatomic mapping (mean 333 ± 40 points) for correlation with LA strain.


RESULTS
Group 1 demonstrated significant deterioration in total LA strain (26.3% ± 1.2% to 21.7% ± 1.2%, P < .05) and increases in Pmax (132 ± 3 ms to 138 ± 3 ms, P < .05) and Pdis (37 ± 2 ms to 42 ± 2 ms, P < .05). AF burden ≥10% was specifically associated with decline in strain and with P-wave prolongation. Conversely, group 2 manifest improvement in total LA strain (21.3% ± 1.7% to 28.6% ± 1.7%, P <.05) and reductions in Pmax (136 ± 4 ms to 119 ± 4 ms, P < .05) and Pdis (47 ± 3 ms to 32 ± 3 ms, P < .05). Change was not significant in group 3. LA mean voltage (r = 0.71, P = .0005), percent low voltage electrograms (r = -0.59, P = .006), percent complex electrograms (r = -0.68, P = .0009), and LA activation time (r = -0.69, P = .001) correlated with total strain as a measure of LA reservoir function.


CONCLUSIONS
High-burden AF is associated with progressive LA structural remodeling. In contrast, AF ablation results in significant reverse remodeling. These data may have implications for timing of ablative intervention.
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia.
Tomos E
TE
Walters
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Ashley
A
Nisbet
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Gwilym M
GM
Morris
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia.
Gabriel
G
Tan
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Megan
M
Mearns
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Eliza
E
Teo
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Nigel
N
Lewis
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
AiVee
A
Ng
Department of Cardiology, Princess Alexandra Hospital, Brisbane, Australia; University of Queensland, Brisbane, Australia.
Paul
P
Gould
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia.
Geoffrey
G
Lee
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Stephen
S
Joseph
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia.
Joseph B
JB
Morton
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia.
Dominica
D
Zentner
Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide, Adelaide, Australia; Royal Adelaide Hospital, Adelaide, Australia.
Prashanthan
P
Sanders
Department of Medicine, University of Melbourne, Melbourne, Australia; Department of Cardiology, Alfred Hospital and Baker IDI, Melbourne, Australia.
Peter M
PM
Kistler
Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia. Electronic address: jon.kalman@mh.org.au.
Jonathan M
JM
Kalman
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D016279:Atrial Function, Left / Q000502:physiology*; D064752:Atrial Remodeling / Q000502:physiology*; D017115:Catheter Ablation / Q000379:methods*; D015331:Cohort Studies; D018450:Disease Progression; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D061665:Time-to-Treatment; D016896:Treatment Outcome; D014672:Vectorcardiography / Q000379:methods
D000889:Anti-Arrhythmia Agents
Atrial fibrillation; Atrial remodeling; Strain imaging