Effectiveness and safety of warfarin initiation in older hemodialysis patients with incident atrial fibrillation

Clin J Am Soc Nephrol. 2011 Nov;6(11):2662-8. doi: 10.2215/CJN.04550511. Epub 2011 Sep 29.


Background and objectives: Although generally recommended in atrial fibrillation (AF) patients, the effectiveness and safety of oral anticoagulation in dialysis patients with AF is unknown.

Design, setting, participants, & measurements: We assembled a cohort of older hemodialysis patients who initiated dialysis without prior record of AF and who had prescription drug benefits through three state-administered programs. The index event was a first hospitalization with diagnosed AF; patients with any recorded prior warfarin use were excluded. Eligible patients survived ≥30 days from discharge, and new warfarin use was recorded from prescription records during that 30-day window. Propensity-matched warfarin users and nonusers were compared using Cox regression. Outcomes included ischemic stroke, hemorrhagic stroke, and mortality.

Results: Among 2313 patients with new AF who survived 30 days from discharge, 249 (10.8%) filled a prescription for warfarin. Comparing 237 warfarin users and 948 propensity-matched nonusers over 2287 person-years of follow-up, the occurrence of ischemic stroke was similar (HR = 0.92; 95% CI, 0.61 to 1.37), whereas warfarin users experienced twice the risk of hemorrhagic stroke (HR = 2.38; 95% CI, 1.15 to 4.96). The risks of stroke, gastrointestinal hemorrhage, and mortality did not differ between groups. As-treated analyses yielded similar findings, as did analyses restricted to patients with CHADS(2) scores ≥2.

Conclusions: Although we confirmed association between warfarin use and hemorrhagic stroke in dialysis patients with AF, we found no association between warfarin use and ischemic stroke. Adequately powered randomized trials are required to conclusively determine the risks and benefits of the studied warfarin indication in hemodialysis patients.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Anticoagulants / adverse effects
  • Anticoagulants / therapeutic use*
  • Atrial Fibrillation / complications
  • Atrial Fibrillation / drug therapy*
  • Atrial Fibrillation / mortality
  • Brain Ischemia / etiology
  • Brain Ischemia / mortality
  • Brain Ischemia / prevention & control*
  • Case-Control Studies
  • Drug Prescriptions
  • Female
  • Hospitalization
  • Humans
  • Intracranial Hemorrhages / etiology
  • Intracranial Hemorrhages / mortality
  • Intracranial Hemorrhages / prevention & control*
  • Kidney Failure, Chronic / complications
  • Kidney Failure, Chronic / mortality
  • Kidney Failure, Chronic / therapy*
  • Logistic Models
  • Male
  • Medicare
  • Middle Aged
  • Proportional Hazards Models
  • Renal Dialysis* / adverse effects
  • Renal Dialysis* / mortality
  • Risk Assessment
  • Risk Factors
  • Stroke / etiology
  • Stroke / mortality
  • Stroke / prevention & control*
  • Survival Rate
  • Time Factors
  • Treatment Outcome
  • United States / epidemiology
  • Warfarin / adverse effects
  • Warfarin / therapeutic use*


  • Anticoagulants
  • Warfarin