title: Atrial high rate episodes detected by pacemaker diagnostics predict death and stroke: report of the Atrial Diagnostics Ancillary Study of the MOde Selection Trial (MOST).
abstract: BACKGROUND
  Some current pacing systems can automatically detect and record atrial tachyarrhythmias that may be asymptomatic. We prospectively studied a 312-patient (pt) subgroup of MOST (MOde Selection Trial), a 2010-patient, 6-year randomized trial of DDDR versus VVIR pacing in sinus node dysfunction (SND). The purpose of the study was to correlate atrial high rate events (AHREs) detected by pacemaker diagnostics with clinical outcomes.
  
  
  RESULTS
  Pacemakers were programmed to log an AHRE when the atrial rate was >220 bpm for 10 consecutive beats. Analysis was confined to patients with at least 1 AHRE duration exceeding 5 minutes. The 312 patients were median age 74 years, 55% female, and 60% had a history of SVT. 160 of 312 (51.3%) patients enrolled had at least 1 AHRE >5 minutes duration over median follow-up of 27 months. Cox proportional hazards analysis assessed the relationship of AHREs with clinical events, adjusting for prognostic variables and baseline covariates. The presence of any AHRE was an independent predictor of the following: total mortality (hazard ratio AHRE versus no AHRE and 95% confidence intervals=2.48 [1.25, 4.91], P=0.0092); death or nonfatal stroke (2.79 [1.51, 5.15], P=0.0011); and atrial fibrillation (5.93 [2.88, 12.2], P=0.0001). There was no significant effect of pacing mode on the presence or absence of AHREs.
  
  
  CONCLUSIONS
  AHRE detected by pacemakers in patients with SND identify patients that are more than twice as likely to die or have a stroke, and 6 times as likely to develop atrial fibrillation as similar patients without AHRE.
authors.affiliation: Division of Electrophysiology , Hackensack University Medical Center, Hackensack, NJ, USA. TayaVG@aol.com
authors.forename: Taya V
authors.initials: TV
authors.lastname: Glotzer
authors.forename: Anne S
authors.initials: AS
authors.lastname: Hellkamp
authors.forename: John
authors.initials: J
authors.lastname: Zimmerman
authors.forename: Michael O
authors.initials: MO
authors.lastname: Sweeney
authors.forename: Raymond
authors.initials: R
authors.lastname: Yee
authors.forename: Roger
authors.initials: R
authors.lastname: Marinchak
authors.forename: James
authors.initials: J
authors.lastname: Cook
authors.forename: Alexander
authors.initials: A
authors.lastname: Paraschos
authors.forename: John
authors.initials: J
authors.lastname: Love
authors.forename: Glauco
authors.initials: G
authors.lastname: Radoslovich
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Lee
authors.forename: Gervasio A
authors.initials: GA
authors.lastname: Lamas
mesh_terms: D000328:Adult; D000368:Aged; D001146:Arrhythmia, Sinus / Q000628:therapy; D001145:Arrhythmias, Cardiac / Q000175:diagnosis; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality*; D002304:Cardiac Pacing, Artificial; D015716:Electrocardiography, Ambulatory; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology