title: Reduction in inappropriate therapy and mortality through ICD programming.
abstract: BACKGROUND
  The implantable cardioverter-defibrillator (ICD) is highly effective in reducing mortality among patients at risk for fatal arrhythmias, but inappropriate ICD activations are frequent, with potential adverse effects.
  
  
  METHODS
  We randomly assigned 1500 patients with a primary-prevention indication to receive an ICD with one of three programming configurations. The primary objective was to determine whether programmed high-rate therapy (with a 2.5-second delay before the initiation of therapy at a heart rate of ≥200 beats per minute) or delayed therapy (with a 60-second delay at 170 to 199 beats per minute, a 12-second delay at 200 to 249 beats per minute, and a 2.5-second delay at ≥250 beats per minute) was associated with a decrease in the number of patients with a first occurrence of inappropriate antitachycardia pacing or shocks, as compared with conventional programming (with a 2.5-second delay at 170 to 199 beats per minute and a 1.0-second delay at ≥200 beats per minute).
  
  
  RESULTS
  During an average follow-up of 1.4 years, high-rate therapy and delayed ICD therapy, as compared with conventional device programming, were associated with reductions in a first occurrence of inappropriate therapy (hazard ratio with high-rate therapy vs. conventional therapy, 0.21; 95% confidence interval [CI], 0.13 to 0.34; P<0.001; hazard ratio with delayed therapy vs. conventional therapy, 0.24; 95% CI, 0.15 to 0.40; P<0.001) and reductions in all-cause mortality (hazard ratio with high-rate therapy vs. conventional therapy, 0.45; 95% CI, 0.24 to 0.85; P=0.01; hazard ratio with delayed therapy vs. conventional therapy, 0.56; 95% CI, 0.30 to 1.02; P=0.06). There were no significant differences in procedure-related adverse events among the three treatment groups.
  
  
  CONCLUSIONS
  Programming of ICD therapies for tachyarrhythmias of 200 beats per minute or higher or with a prolonged delay in therapy at 170 beats per minute or higher, as compared with conventional programming, was associated with reductions in inappropriate therapy and all-cause mortality during long-term follow-up. (Funded by Boston Scientific; MADIT-RIT ClinicalTrials.gov number, NCT00947310.).
authors.affiliation: Department of Medicine, University of Rochester Medical Center, Rochester, NY 14642-0653, USA. heartajm@heart.rochester.edu
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Claudio
authors.initials: C
authors.lastname: Schuger
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Beck
authors.forename: Mary W
authors.initials: MW
authors.lastname: Brown
authors.forename: David S
authors.initials: DS
authors.lastname: Cannom
authors.forename: James P
authors.initials: JP
authors.lastname: Daubert
authors.forename: N A Mark
authors.initials: NA
authors.lastname: Estes
authors.forename: Henry
authors.initials: H
authors.lastname: Greenberg
authors.forename: W Jackson
authors.initials: WJ
authors.lastname: Hall
authors.forename: David T
authors.initials: DT
authors.lastname: Huang
authors.forename: Josef
authors.initials: J
authors.lastname: Kautzner
authors.forename: Helmut
authors.initials: H
authors.lastname: Klein
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Brian
authors.initials: B
authors.lastname: Olshansky
authors.forename: Morio
authors.initials: M
authors.lastname: Shoda
authors.forename: David
authors.initials: D
authors.lastname: Wilber
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
mesh_terms: D000368:Aged; D017147:Defibrillators, Implantable / Q000009:adverse effects; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D013610:Tachycardia / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D013997:Time Factors