title: Risk of proarrhythmic events in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study: a multivariate analysis.
abstract: OBJECTIVE
  This study examined the risk of proarrhythmic events in patients receiving antiarrhythmic drugs for treatment of atrial fibrillation (AF) according to present-day safety guidelines.
  
  
  BACKGROUND
  Advances in understanding the proarrhythmic risk of antiarrhythmic drugs has led to development of safety guidelines for these agents. Such guidelines were used in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study.
  
  
  METHODS
  This study was an analysis of the risk of arrhythmic events (arrhythmic death, resuscitated cardiac arrest, sustained ventricular tachycardia (VT), and torsade de pointes VT) in the antiarrhythmic drug arm of the AFFIRM study. Each time an antiarrhythmic drug was begun, it was counted as an exposure to that drug and the risk of an arrhythmic event was calculated.
  
  
  RESULTS
  A total of 2,033 patients received 3,030 exposures to antiarrhythmic drugs. Ninety-six arrhythmic events occurred by six years. Patients with a left ventricular ejection fraction <40% had more arrhythmic events. Twelve documented cases of torsade de pointes VT were noted. The incidence of torsade de pointes was 0.6% at five years (95% confidence interval 0.32 to 1.07).
  
  
  CONCLUSIONS
  The overall risk of adverse arrhythmic events upon exposure to antiarrhythmic drugs in the AFFIRM study was reasonably low. Strict criteria for the safe use of antiarrhythmic drugs were successful in minimizing proarrhythmic events.
authors.affiliation: Heart and Vascular Research Center, Hamann 3rd Floor, MetroHealth Campus, Case Western Reserve University, 2500 MetroHealth Drive, Cleveland, Ohio 44109-1998, USA. ekaufman@metrohealth.org
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Kaufman
authors.forename: Paul A
authors.initials: PA
authors.lastname: Zimmermann
authors.forename: Ted
authors.initials: T
authors.lastname: Wang
authors.forename: George W
authors.initials: GW
authors.lastname: Dennish
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Barrell
authors.forename: Mary L
authors.initials: ML
authors.lastname: Chandler
authors.forename: H Leon
authors.initials: HL
authors.lastname: Greene
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D012737:Sex Factors; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents