Use of intravenous heparin by North American neurologists: do the data matter?
OBJECTIVE
Our aim was to determine current usage patterns of intravenous heparin for patients with acute ischemic stroke.


METHODS
A survey was undertaken of 280 neurologists from the United States and 270 neurologists from Canada. Brief vignettes were presented for the following 5 scenarios: stroke in evolution, atrial fibrillation-related stroke (A FIB), vertebrobasilar stroke, carotid territory stroke, and multiple transient ischemic attacks. The effect of medicolegal factors was also ascertained. Statistical comparisons were done with chi-squared testing.


RESULTS
US neurologists were significantly more likely than Canadian neurologists to use intravenous heparin for patients with stroke in evolution (51% versus 33%, P<0.001), vertebrobasilar stroke (30% versus 8%, P<0.001), carotid territory stroke (31% versus 4%, P<0.001), and multiple transient ischemic attacks (47% versus 9%, P<0.001). The vast majority of US and Canadian neurologists would use intravenous heparin for acute stroke patients with A FIB (88% and 84%, respectively). US neurologists more often cited medicolegal factors as a potential influence on the decision-making process than Canadian neurologists (33% versus 10%, P<0.001).


CONCLUSIONS
In several clinical scenarios, US neurologists were significantly more likely than Canadian neurologists to use intravenous heparin. Fears regarding medicolegal consequences may partially explain the treatment disparity. Despite the publication of 4 clinical trials, which have not shown any long-term benefit for patients with acute stroke and A FIB (International Stroke Trial, Heparin in Acute Embolic Stroke Trial) or cardioembolic stroke (Trial of Org 10172 in Acute Stroke Treatment, the Tinzaparin in Acute Ischemic Stroke Trial), both US and Canadian neurologists would use intravenous heparin in large numbers for this condition. Further studies are warranted to investigate the lack of impact of "negative" studies on clinician behavior.
Al-Sadat
Ahmad
A
Department of Neurology and Comprehensive Stroke Program, Wayne State University, Detroit, Mich 48201, USA.
Sunbulli
Mohammad
M
Chaturvedi
Seemant
S
D000208:Acute Disease; D002545:Brain Ischemia / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data; D004363:Drug Utilization / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D019538:Health Care Surveys; D006493:Heparin / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D016365:Liability, Legal; D009462:Neurology / Q000706:statistics & numerical data*; D010818:Practice Patterns, Physicians' / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D020521:Stroke / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
D006493:Heparin