title: Warfarin in atrial fibrillation patients with moderate chronic kidney disease.
abstract: OBJECTIVE
  The efficacy of adjusted-dose warfarin for prevention of stroke in atrial fibrillation patients with stage 3 chronic kidney disease (CKD) is unknown.
  
  
  METHODS
  Patients with stage 3 CKD participating in the Stroke Prevention in Atrial Fibrillation 3 trials were assessed to determine the effect of warfarin anticoagulation on stroke and major hemorrhage, and whether CKD status independently contributed to stroke risk. High-risk participants (n = 1044) in the randomized trial were assigned to adjusted-dose warfarin (target international normalized ratio 2 to 3) versus aspirin (325 mg) plus fixed, low-dose warfarin (subsequently shown to be equivalent to aspirin alone). Low-risk participants (n = 892) all received 325 mg aspirin daily. The primary outcome was ischemic stroke (96%) or systemic embolism (4%).
  
  
  RESULTS
  Among the 1936 participants in the two trials, 42% (n = 805) had stage 3 CKD at entry. Considering the 1314 patients not assigned to adjusted-dose warfarin, the primary event rate was double among those with stage 3 CKD (hazard ratio 2.0, 95% CI 1.2, 3.3) versus those with a higher estimated GFR (eGFR). Among the 516 participants with stage 3 CKD included in the randomized trial, ischemic stroke/systemic embolism was reduced 76% (95% CI 42, 90; P < 0.001) by adjusted-dose warfarin compared with aspirin/low-dose warfarin; there was no difference in major hemorrhage (5 patients versus 6 patients, respectively).
  
  
  CONCLUSIONS
  Among atrial fibrillation patients participating in the Stroke Prevention in Atrial Fibrillation III trials, stage 3 CKD was associated with higher rates of ischemic stroke/systemic embolism. Adjusted-dose warfarin markedly reduced ischemic stroke/systemic embolism in high-risk atrial fibrillation patients with stage 3 CKD.
authors: Department of Neurology, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA. robert.hart@phri.ca
authors: Robert G
authors: RG
authors: Hart
authors: Lesly A
authors: LA
authors: Pearce
authors: Richard W
authors: RW
authors: Asinger
authors: Charles A
authors: CA
authors: Herzog
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001241:Aspirin / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D001777:Blood Coagulation / Q000187:drug effects; D002170:Canada; D016009:Chi-Square Distribution; D002908:Chronic Disease; D004359:Drug Therapy, Combination; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D019934:International Normalized Ratio; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000150:complications* / Q000175:diagnosis; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin; D001241:Aspirin