title: Characterization and predictors of first and subsequent inappropriate ICD therapy by heart rate ranges: Result of the MADIT-RIT efficacy analysis.
abstract: BACKGROUND
  Data on inappropriate implantable cardioverter-defibrillator (ICD) therapy and effects of programming by heart rate are lacking.
  
  
  OBJECTIVE
  We aimed to characterize inappropriate ICD therapy and assess the effects of novel programming by heart rate.
  
  
  METHODS
  Incidence and causes of inappropriate therapy by heart rate range (below or above 200 bpm) were assessed. Predictors of inappropriate therapy and effects of programming by heart rate were evaluated with multivariate Cox regression models. Crossovers were excluded.
  
  
  RESULTS
  Inappropriate therapy occurred in 9.2% of the total patient population, with 19% of patients randomized to study arm A, 3.6% in arm B, and 4.7% in arm C. Inappropriate therapies <200 bpm were attributable to supraventricular tachycardia (SVT)/sinus tachycardia (78%) or atrial fibrillation/flutter (20%). Inappropriate therapy ≥200 bpm occurred because of SVT (47%), atrial fibrillation/flutter (41%), or electromagnetic interference (13%). Conventional ICD programming was associated with more inappropriate therapy <200 bpm than high-rate or delayed therapy, as were younger age, history of atrial arrhythmia, advanced New York Heart Association functional class, ICD versus cardiac resynchronization therapy with defibrillator, and absence of diabetes. High-rate and long-delay therapy significantly reduced the risk of inappropriate therapy in the <200 bpm range. Long delay was associated with further reduction of fast (≥200 bpm) inappropriate therapy (P = .032) and a reduction in subsequent inappropriate episodes (P = .006).
  
  
  CONCLUSIONS
  In MADIT-RIT, inappropriate ICD therapy is most frequent at rates below 200 bpm and can be predicted, and effectively prevented, with high-rate cutoff programming. Long-delay therapy effectively reduces fast inappropriate therapy ≥200 bpm and subsequent events. [
  
  
  BACKGROUND
  http://clinicaltrials.gov/ct2/show/NCT00947310].
authors.affiliation: University of Rochester Medical Center, Rochester, New York.
authors.forename: Valentina
authors.initials: V
authors.lastname: Kutyifa
authors.affiliation: Duke University, Cardiology, Durham, North Carolina.
authors.forename: James P
authors.initials: JP
authors.lastname: Daubert
authors.affiliation: University of Iowa, Cardiology Department, Iowa City, Iowa.
authors.forename: Brian
authors.initials: B
authors.lastname: Olshansky
authors.affiliation: University of Rochester Medical Center, Rochester, New York.
authors.forename: David T
authors.initials: DT
authors.lastname: Huang
authors.affiliation: University of Rochester Medical Center, Rochester, New York.
authors.forename: Claire
authors.initials: C
authors.lastname: Zhang
authors.affiliation: University of Rochester Medical Center, Rochester, New York.
authors.forename: Anne-Christine H
authors.initials: AC
authors.lastname: Ruwald
authors.affiliation: University of Rochester Medical Center, Rochester, New York.
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.affiliation: University of Rochester Medical Center, Rochester, New York.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.affiliation: University of Rochester Medical Center, Rochester, New York.
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.affiliation: The Henry Ford Hospital, Cardiac Electrophysiology, Detroit, Michigan. Electronic address: cschuge1@hfhs.org.
authors.forename: Claudio
authors.initials: C
authors.lastname: Schuger
mesh_terms: D000328:Adult; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D054143:Heart Failure, Systolic / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate / Q000639:trends; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: High-rate cutoff; Implantable cardioverter-defibrillator; Long delay; Predictors; Programming; Subsequent inappropriate therapy; Therapy