title: Pericardial fat is associated with atrial fibrillation severity and ablation outcome.
abstract: OBJECTIVE
  The aim of this study was to characterize the relationship between pericardial fat and atrial fibrillation (AF).
  
  
  BACKGROUND
  Obesity is an important risk factor for AF. Pericardial fat has been hypothesized to exert local pathogenic effects on nearby cardiac structures above and beyond that of systemic adiposity.
  
  
  METHODS
  One hundred ten patients undergoing first-time AF ablation and 20 reference patients without AF underwent cardiac magnetic resonance imaging for the quantification of periatrial, periventricular, and total pericardial fat volumes using a previously validated technique. Together with body mass index and body surface area, these were examined in relation to the presence of AF, the severity of AF, left atrial volume, and long-term AF recurrence after ablation.
  
  
  RESULTS
  Pericardial fat volumes were significantly associated with the presence of AF, AF chronicity, and AF symptom burden (all p values <0.05). Pericardial fat depots were also predictive of long-term AF recurrence after ablation (p = 0.035). Finally, pericardial fat depots were also associated with left atrial volume (total pericardial fat: r = 0.46, p < 0.001). Importantly, these associations persisted after multivariate adjustment and additional adjustment for body weight. In contrast, however, systemic measures of adiposity, such as body mass index and body surface area, were not associated with these outcomes in multivariate-adjusted models.
  
  
  CONCLUSIONS
  Pericardial fat is associated with the presence of AF, the severity of AF, left atrial volumes, and poorer outcomes after AF ablation. These associations are both independent of and stronger than more systemic measures of adiposity. These findings are consistent with the hypothesis of a local pathogenic effect of pericardial fat on the arrhythmogenic substrate supporting AF.
authors.affiliation: Centre for Heart Rhythm Disorders (CHRD), Royal Adelaide Hospital and the University of Adelaide, Adelaide, Australia.
authors.forename: Christopher X
authors.initials: CX
authors.lastname: Wong
authors.forename: Hany S
authors.initials: HS
authors.lastname: Abed
authors.forename: Payman
authors.initials: P
authors.lastname: Molaee
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Nelson
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Brooks
authors.forename: Gautam
authors.initials: G
authors.lastname: Sharma
authors.forename: Darryl P
authors.initials: DP
authors.lastname: Leong
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Lau
authors.forename: Melissa E
authors.initials: ME
authors.lastname: Middeldorp
authors.forename: Kurt C
authors.initials: KC
authors.lastname: Roberts-Thomson
authors.forename: Gary A
authors.initials: GA
authors.lastname: Wittert
authors.forename: Walter P
authors.initials: WP
authors.lastname: Abhayaratna
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Worthley
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000473:pathology*; D012720:Severity of Illness Index; D016896:Treatment Outcome