title: Risk of arrhythmia and sudden death in patients with asymptomatic preexcitation: a meta-analysis.
abstract: BACKGROUND
  The incidence of sudden cardiac death (SCD) and the management of this risk in patients with asymptomatic preexcitation remain controversial. The purpose of this meta-analysis was to define the incidence of SCD and supraventricular tachycardia in patients with asymptomatic Wolff-Parkinson-White ECG pattern.
  
  
  RESULTS
  We performed a systematic search of prospective, retrospective, randomized, or cohort English-language studies in EMBASE and Medline through February 2011. Studies reporting asymptomatic patients with preexcitation who did not undergo ablation were included. Twenty studies involving 1869 patients met our inclusion criteria. Participants were primarily male with a mean age ranging from 7 to 43 years. Ten SCDs were reported involving 11 722 person-years of follow-up. Seven studies originated from Italy and reported 9 SCDs. The risk of SCD is estimated at 1.25 per 1000 person-years (95% confidence interval [CI], 0.57-2.19). A total of 156 supraventricular tachycardias were reported involving 9884 person-years from 18 studies. The risk of supraventricular tachycardia was 16 (95% CI, 10-24) events per 1000 person-years of follow-up. Children had numerically higher SCD (1.93 [95% CI, 0.57-4.1] versus 0.86 [95% CI, 0.28-1.75]; P=0.07) and supraventricular tachycardia (20 [95% CI, 12-31] versus 14 [95% CI, 6-25]; P=0.38) event rates compared with adults.
  
  
  CONCLUSIONS
  The low incidence of SCD and low risk of supraventricular tachycardia argue against routine invasive management in most asymptomatic patients with the Wolff-Parkinson-White ECG pattern.
authors.affiliation: Division of Cardiology, University of Western Ontario, London, Ontario, Canada. manojobey@yahoo.com
authors.forename: Manoj N
authors.initials: MN
authors.lastname: Obeyesekere
authors.forename: Peter
authors.initials: P
authors.lastname: Leong-Sit
authors.forename: David
authors.initials: D
authors.lastname: Massel
authors.forename: Jaimie
authors.initials: J
authors.lastname: Manlucu
authors.forename: Simon
authors.initials: S
authors.lastname: Modi
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Krahn
authors.forename: Allan C
authors.initials: AC
authors.lastname: Skanes
authors.forename: Raymond
authors.initials: R
authors.lastname: Yee
authors.forename: Lorne J
authors.initials: LJ
authors.lastname: Gula
authors.forename: George J
authors.initials: GJ
authors.lastname: Klein
mesh_terms: D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D015995:Prevalence; D012307:Risk Factors; D013617:Tachycardia, Supraventricular / Q000401:mortality*; D014927:Wolff-Parkinson-White Syndrome / Q000401:mortality*