title: Gamma-glutamyl transferase predicts recurrences of atrial fibrillation after catheter ablation.
abstract: BACKGROUND
  Catheter ablation is a popular therapy of atrial fibrillation (AF). Gamma-glutamyl transferase (GGT) is known as a marker of oxidative stress. The objective of this study was to ascertain the relationship between levels of GGT and recurrence of AF after catheter ablation.
  
  
  METHODS
  A total of 102 paroxysmal AF patients who underwent cryoballoon catheter ablation were enrolled. Serum samples were obtained to evaluate GGT levels before catheter ablation. Cox regression analysis was used to estimate the predictors of AF recurrence.
  
  
  RESULTS
  Mean age of the cohort was 49.9 ± 11.7 and 63% of the patients were male. After a mean follow-up of 20 months, 19 (23%) patients had AF recurrences. The baseline GGT levels were significantly higher in patients who had AF recurrence [27 U/L (17-36) vs 18 U/L (13-22), P = 0.002]. The optimal cut-off value of GGT to predict AF recurrence was 23.5 U/L according to receiver operating characteristic curve analysis (area under the curve 0.72, P = 0.002). In the multivariable Cox regression analysis, baseline GGT > 23.5 was the only independent predictor of AF recurrence (hazard ratio (HR) 4.47, 95% confidence interval [1.66-12.09], P = 0.003).
  
  
  CONCLUSIONS
  Our results indicate that elevated GGT is associated with AF recurrence. A simple measurement of GGT may help us to identify high-risk patients undergoing catheter ablation for AF.
authors.forename: Fatih Mehmet
authors.initials: FM
authors.lastname: Uçar
authors.forename: Esra
authors.initials: E
authors.lastname: Gucuk İpek
authors.forename: Burak
authors.initials: B
authors.lastname: Acar
authors.forename: Murat
authors.initials: M
authors.lastname: Gul
authors.forename: Abdullah
authors.initials: A
authors.lastname: Tunçez
authors.forename: Özeke
authors.initials: Ö
authors.lastname: Özeke
authors.forename: Bilal
authors.initials: B
authors.lastname: Geyik
authors.forename: Serkan
authors.initials: S
authors.lastname: Topaloglu
authors.forename: Dursun
authors.initials: D
authors.lastname: Aras
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012008:Recurrence; D013997:Time Factors; D016896:Treatment Outcome; D014421:Turkey; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D005723:gamma-Glutamyltransferase
keywords: Gamma-glutamyl transferase; atrial fibrillation; catheter ablation; outcome