<div><b>Impact of Pre-ablation Weight Loss on the Success of Catheter
Ablation for Atrial Fibrillation</b></div><div>Abdul Hafiz Al Tannir BS, Marwan M. Refaat MD</div><div>Department of Internal Medicine, Division of Cardiology, American
University of Beirut Medical Center, Beirut, Lebanon</div><div>Running Title: Pre-ablation Weight Loss and Success of AF Ablation</div><div>Disclosures: None</div><div>Funding: None</div><div>Keywords: Cardiac Arrhythmias, Cardiovascular Diseases, Heart Diseases,
Weight Loss, Catheter Ablation, Atrial Fibrillation</div><div>Words: 621 (excluding references)</div><div>Correspondence:</div><div>Marwan M. Refaat, MD, FACC, FAHA, FHRS, FASE, FESC, FACP, FRCP</div><div>Associate Professor of Medicine</div><div>Director, Cardiovascular Fellowship Program</div><div>Department of Internal Medicine, Cardiovascular Medicine/Cardiac
Electrophysiology</div><div>Department of Biochemistry and Molecular Genetics</div><div>American University of Beirut Faculty of Medicine and Medical Center</div><div>PO Box 11-0236, Riad El-Solh 1107 2020- Beirut, Lebanon</div><div>Fax: +961-1-370814</div><div>Clinic: +961-1-759616 or +961-1-355500 or +961-1-350000/+961-1-374374
Extension 5800</div><div>Office: +961-1-350000/+961-1-374374 Extension 5353 or Extension 5366
(Direct)</div><div>Email: mr48@aub.edu.lb</div><div>In the United States, the prevalence of obese individuals has risen
3-fold since 1960, with 1 in every 3 persons being obese. The effect of
weight changes on the progression on atrial fibrillation is
well-established but the effect of pre-ablation weight loss on the
recurrence of atrial fibrillation is not well-studied. Atrial
fibrillation is the most frequently encountered cardiac arrhythmia
[1]; it currently affects around 2.7 million people in the United
States of America and is estimated that 6-12 million people will suffer
from this condition by 2050 [2, 3]. Pulmonary vein isolation is the
primary target for cardiac ablation; it can be achieved either by
radiofrequency (RF) or cryoballoon ablation (CBA) [4, 5]. The FIRE
and ICE trial conducted by Kuck et al showed that CBA therapy was
associated with significantly fewer recurrence, rehospitalization, and
cardioversion rates [6]. Several studies suggest the preferred use
of CBA in treating atrial fibrillation in obese patients due to the
increased surface area for ablation [4].</div><div>Obesity has adverse effects on the structure and hemodynamics of the
heart and it is a well-established risk factor for the development of
atrial fibrillation [3]. A prospective cohort study performed by
Pathak et al showed that progressive weight loss in obese and overweight
patients resulted in dose-dependent effects on freedom from atrial
fibrillation (FFAF) [7]. Similarly, Middeldrop et al, concluded that
obesity is associated with the progression of the disease while weight
loss is associated with reversal of the progression [8]. Limited
data is available regarding the effect of weight loss on the recurrence
of atrial fibrillation post-ablation. Current guidelines recommend
lifestyle modifications, including a healthy diet and exercise, for
overweight and obese patients before ablation [8, 9].</div><div>The study of Peigh et al. is a retrospective cohort study from
2012-2017; 607 patients met the inclusion criteria. The aim of the study
is to assess the impact of patient-directed weight loss 1 year before
CBA on FFAP 15 months after ablation. The authors addressed an important
topic that is poorly understood. Obese patients have a significantly
lower FFAF rate 40-50% than the overall population 60-80%. The study
selectively included patients undergoing CBA therapy. The follow-up time
was 1-year post-ablation. The study concluded that, with the exception
of non-obese patients with persistent atrial fibrillation, weight loss
is associated with a significantly increased FFAF while weight gain led
to a decrease in FFAF. A similar study assessed the impacted of
physician-mediated risk control in patients undergoing RF ablation for
atrial fibrillation [10]. A total of 149 patients were included in
the prospective cohort study. The study showed a positive association
between physician-directed weight loss (≥ 10%) and FFAF in symptomatic
obese patients. The study performed by Peigh et al, included though a
larger subject group (607) than LEGACY (141); however, the LEGACY is a
prospective cohort study that is more suitable to monitor the
fluctuation in patients’ variables before ablation.</div><div>This study was well conducted but has the limitations of retrospective
studies; a prospective cohort study would better monitor the variations
in patients’ variables pre-ablation. In addition, as the authors stated,
asymptomatic atrial fibrillation episodes may go unnoticed.</div><div>Patients with atrial fibrillation, particularly those who are obese,
should be advised to lose weight prior to catheter ablation. Lifestyle
modifications should not be limited to patients undergoing ablation; the
effect of weight loss on disease progression is well-established. Due to
the overgrowing prevalence of atrial fibrillation and obesity worldwide,
more studies are encouraged to better understand the ideal lifestyle
management in patients. Larger prospective cohort studies should be
conducted in order to validate the results. There is also an ongoing
randomized clinical trial BAROS (Bariatric Atrial Return of Sinus Trial)
[NCT 04050969] which will provide more data on this topic.</div>