title: Impact of metabolic syndrome on the risk of atrial fibrillation recurrence after catheter ablation: systematic review and meta-analysis.
abstract: OBJECTIVE
  The impact of metabolic syndrome (MetS) on recurrence of atrial fibrillation (AF) after catheter ablation remains uncertain. We conducted a meta-analysis to summarize the relative risks (RR) of AF recurrence after catheter ablation in patients with vs. without MetS and its components.
  
  
  METHODS
  Among 839 articles identified from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, we included 23 studies with a total of 12,924 patients (7,594 with paroxysmal AF and 5,330 with nonparoxysmal AF) for analysis. Five of these had complete information on MetS components. Variables assessed comprised study design and population characteristics, AF ablation methods, use of anti-arrhythmic drugs, AF recurrence ascertainment methods, adjustment variables, and other quality indicators.
  
  
  RESULTS
  Our meta-analysis found an elevated risk of AF recurrence after ablation in patients with vs. without MetS (pooled RR, 1.63; 95 % confidence interval (CI), 1.25-2.12). Among components of MetS, hypertension was a predictor of AF post-ablation recurrence in studies without adjustment for other MetS components (RR, 1.62; 95 % CI, 1.23-2.13) but not in those adjusting for two or more additional MetS components (RR, 1.03; 95 % CI, 0.88-1.20). There was a borderline association between overweight/obesity and AF recurrence after ablation (RR, 1.27; 95 % CI, 0.99-1.64).
  
  
  CONCLUSIONS
  MetS is associated with an increased risk of AF recurrence after catheter ablation. Further study of the MetS and its components as determinants of AF risk could help refine patient selection and improve procedural outcomes.
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA, kul983@mail.harvard.edu.
authors.forename: Kueiyu Joshua
authors.initials: KJ
authors.lastname: Lin
authors.forename: Soung Ick
authors.initials: SI
authors.lastname: Cho
authors.forename: Nidhish
authors.initials: N
authors.lastname: Tiwari
authors.forename: Michael
authors.initials: M
authors.lastname: Bergman
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Kizer
authors.forename: Eugen C
authors.initials: EC
authors.lastname: Palma
authors.forename: Cynthia C
authors.initials: CC
authors.lastname: Taub
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D017115:Catheter Ablation; D006801:Humans; D024821:Metabolic Syndrome / Q000503:physiopathology*; D012008:Recurrence; D012306:Risk; D012307:Risk Factors