title: Annual atrial tachyarrhythmia burden determined by device interrogation in patients with cardiac implanted electronic devices is associated with a risk of ischaemic stroke independent of known risk factors.
abstract: OBJECTIVE
  This study evaluated the risk of non-fatal ischaemic stroke associated with increased long-term cumulative duration of atrial tachycardia (AT).
  
  
  METHODS
  We retrospectively reviewed the records of 260 patients with cardiovascular implantable electronic devices capable of monitoring AT. Patients were separated into zero, low and high AT burden groups. The cut-off point between low and high AT burden was defined by the median value of AT burden in the non-zero AT burden groups (5% in 1 year, about 18 days annually). The primary outcome was non-fatal ischaemic stroke.
  
  
  RESULTS
  The mean patient age was 63.3 ± 13.7 years, the average follow-up was 7.0 years and 10 patients had strokes. Multivariate analysis showed only hypertension and a diagnosis of atrial fibrillation (AF) were associated with stroke. The risk of stroke in patients with hypertension was 12.57-fold higher than in those without hypertension, and was 20.81-fold higher in patients with paroxysmal AF and 162.59-fold higher in patients with chronic AF than in those without AF. Kaplan-Meier analysis showed that stroke-free survival was significantly different in the three AT burden groups (P = 0.002, long-rank test); the rate was greatest in the zero AT burden group, followed by the low AT burden group and was lowest in the high AT burden group.
  
  
  CONCLUSIONS
  Patients who accumulated an AT duration exceeding 5% (18 days) of the total time in any of the 1-year periods are more likely to have an ischaemic stroke than those who have a low or zero AT burden.
authors: Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors: Szu-Heng
authors: SH
authors: Wang
authors: Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors: Yu-Chuan
authors: YC
authors: Kang
authors: Division of Cardiology, Chang-Gung Memorial Hospital, Linkou, Taiwan.
authors: Chun-Chieh
authors: CC
authors: Wang
authors: Division of Cardiology, Chang-Gung Memorial Hospital, Linkou, Taiwan.
authors: Ming-Shien
authors: MS
authors: Wen
authors: Division of Cardiology, Chang-Gung Memorial Hospital, Linkou, Taiwan.
authors: Kuo-Chun
authors: KC
authors: Hung
authors: Division of Cardiology, Chang-Gung Memorial Hospital, Linkou, Taiwan.
authors: Chao-Yung
authors: CY
authors: Wang
authors: Division of Cardiology, Chang-Gung Memorial Hospital, Linkou, Taiwan Department of Cardiology, Chang-Gung Memorial Hospital, Xiamen, China skyheart0826@gmail.com.
authors: Tien-Hsing
authors: TH
authors: Chen
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D002545:Brain Ischemia / Q000453:epidemiology / Q000209:etiology*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors
keywords: Atrial fibrillation; Atrial tachyarrhythmia; Cardiac implantable device; Ischaemic stroke