title: Bariatric Surgery and the Risk of New-Onset Atrial Fibrillation in Swedish Obese Subjects.
abstract: BACKGROUND
  Obesity is a risk factor for atrial fibrillation, which in turn is associated with stroke, heart failure, and increased all-cause mortality.
  
  
  OBJECTIVE
  The authors investigated whether weight loss through bariatric surgery may reduce the risk of new-onset atrial fibrillation.
  
  
  METHODS
  SOS (Swedish Obese Subjects) is a prospective matched cohort study conducted at 25 surgical departments and 480 primary healthcare centers in Sweden. The cohort was recruited between 1987 and 2001. Among 4,021 obese individuals with sinus rhythm and no history of atrial fibrillation, 2,000 underwent bariatric surgery (surgery group), and 2,021 matched obese control subjects received usual care (control group). The outcome, first-time atrial fibrillation, was ascertained by crosschecking the SOS database with the Swedish National Patient Register on inpatient and outpatient diagnosis codes.
  
  
  RESULTS
  During a median follow-up of 19 years, first time atrial fibrillation occurred in 247 patients (12.4%) in the surgical group, and in 340 (16.8%) control subjects. The risk of developing atrial fibrillation was 29% lower in the surgery group versus the control group (hazard ratio: 0.71; 95% confidence interval: 0.60 to 0.83; p < 0.001). Younger individuals benefited more from surgical intervention than those who were older (p value for interaction 0.001). Also, those with a high diastolic blood pressure benefitted more from surgery than did those with a low diastolic blood pressure (p for interaction = 0.028).
  
  
  CONCLUSIONS
  Compared with usual care, weight loss through bariatric surgery reduced the risk of atrial fibrillation among persons being treated for severe obesity. The risk reduction was more apparent in younger people and in those with higher blood pressure.
authors.affiliation: Department of Cardiology, Sahlgrenska University Hospital and Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Shabbar
authors.initials: S
authors.lastname: Jamaly
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Carlsson
authors.affiliation: Chronic Disease Epidemiology and Prevention Unit, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Peltonen
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Jacobson
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Sjöström
authors.affiliation: Department of Cardiology, Sahlgrenska University Hospital and Institute of Medicine, University of Gothenburg, Gothenburg, Sweden. Electronic address: kristjan.karason@gu.se.
authors.forename: Kristjan
authors.initials: K
authors.lastname: Karason
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D050110:Bariatric Surgery / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000601:surgery; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
keywords: atrial fibrillation; bariatric surgery; obesity; weight loss