Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis.
BACKGROUND
Atherosclerotic intracranial arterial stenosis is an important cause of stroke. Warfarin is commonly used in preference to aspirin for this disorder, but these therapies have not been compared in a randomized trial.


METHODS
We randomly assigned patients with transient ischemic attack or stroke caused by angiographically verified 50 to 99 percent stenosis of a major intracranial artery to receive warfarin (target international normalized ratio, 2.0 to 3.0) or aspirin (1300 mg per day) in a double-blind, multicenter clinical trial. The primary end point was ischemic stroke, brain hemorrhage, or death from vascular causes other than stroke.


RESULTS
After 569 patients had undergone randomization, enrollment was stopped because of concerns about the safety of the patients who had been assigned to receive warfarin. During a mean follow-up period of 1.8 years, adverse events in the two groups included death (4.3 percent in the aspirin group vs. 9.7 percent in the warfarin group; hazard ratio for aspirin relative to warfarin, 0.46; 95 percent confidence interval, 0.23 to 0.90; P=0.02), major hemorrhage (3.2 percent vs. 8.3 percent, respectively; hazard ratio, 0.39; 95 percent confidence interval, 0.18 to 0.84; P=0.01), and myocardial infarction or sudden death (2.9 percent vs. 7.3 percent, respectively; hazard ratio, 0.40; 95 percent confidence interval, 0.18 to 0.91; P=0.02). The rate of death from vascular causes was 3.2 percent in the aspirin group and 5.9 percent in the warfarin group (P=0.16); the rate of death from nonvascular causes was 1.1 percent and 3.8 percent, respectively (P=0.05). The primary end point occurred in 22.1 percent of the patients in the aspirin group and 21.8 percent of those in the warfarin group (hazard ratio, 1.04; 95 percent confidence interval, 0.73 to 1.48; P=0.83).


CONCLUSIONS
Warfarin was associated with significantly higher rates of adverse events and provided no benefit over aspirin in this trial. Aspirin should be used in preference to warfarin for patients with intracranial arterial stenosis.
Chimowitz
Marc I
MI
Department of Neurology, School of Medicine, Emory University, Atlanta, USA. mchimow@emory.edu
Lynn
Michael J
MJ
Howlett-Smith
Harriet
H
Stern
Barney J
BJ
Hertzberg
Vicki S
VS
Frankel
Michael R
MR
Levine
Steven R
SR
Chaturvedi
Seemant
S
Kasner
Scott E
SE
Benesch
Curtis G
CG
Sila
Cathy A
CA
Jovin
Tudor G
TG
Romano
Jose G
JG
D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000401:mortality; D004311:Double-Blind Method; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000150:complications / Q000188:drug therapy*; D002546:Ischemic Attack, Transient / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009026:Mortality; D055502:Secondary Prevention; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D014859:Warfarin; D001241:Aspirin