title: Outcomes in atrial fibrillation patients on combined warfarin & antiarrhythmic therapy.
abstract: BACKGROUND
  This retrospective cohort study compared rates of treatment persistence, incidences of de novo stroke, arterial embolism, and hemorrhage/bleeding, and healthcare resource use and costs between atrial fibrillation/flutter (AF/AFL) patients receiving concomitant warfarin (W)+amiodarone (A) or warfarin+other antiarrhythmic drug (OAAD) therapy in real-world practice.
  
  
  METHODS
  The Ingenix IMPACT database (1997-2009) was used to identify patients with ≥ 1 diagnostic claim for AF/AFL and concurrent pharmacy claims (≥ 60 days' supply) for W and A (n=4238) or W+OAAD (n=6332) within the first 90 days of initiating therapy. Outcomes of interest were assessed over 12 months following initiation of dual therapy.
  
  
  RESULTS
  The W+A cohort was older than the W+OAAD cohort (mean 66.5 vs. 61.9 years) and had greater baseline comorbidity. The W+A cohort had significantly 1) lower rates of treatment persistence; 2) higher incidences of de novo stroke (hazard ratio [HR] 1.24), arterial embolism (HR 1.48) and combined stroke/hemorrhage/bleeding/arterial embolism (HR 1.25); 3) more frequent inpatient (incidence rate ratio [IRR] 1.25), emergency room (IRR 1.16) and outpatient (IRR 1.07) admissions; and 4) higher incidences of cardiovascular- (IRR 1.35) and arterial embolism- (IRR 1.94) related healthcare use than the W+OAAD cohort. Incremental total healthcare costs over 12 months were $4114 ($2397 inpatient; $1171 outpatient).
  
  
  CONCLUSIONS
  Allowing for differences in prescribing practice, AF/AFL patients treated with W+A are at higher risk of stroke and arterial embolism, and have higher healthcare use and costs, than patients receiving W+OAAD.
authors.affiliation: Analysis Group Inc., Boston, Massachusetts, USA. aguerin@analysisgroup.com
authors.forename: Annie
authors.initials: A
authors.lastname: Guérin
authors.forename: Jay
authors.initials: J
authors.lastname: Lin
authors.forename: Mehul
authors.initials: M
authors.lastname: Jhaveri
authors.forename: Eric Q
authors.initials: EQ
authors.lastname: Wu
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Yu
authors.forename: Martin
authors.initials: M
authors.lastname: Cloutier
authors.forename: Genevieve
authors.initials: G
authors.lastname: Gauthier
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Alpert
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage* / Q000191:economics; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000191:economics / Q000453:epidemiology*; D015331:Cohort Studies; D016208:Databases, Factual / Q000639:trends; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage* / Q000191:economics
chemical_list: D000889:Anti-Arrhythmia Agents; D014859:Warfarin