Abstract 147: Cannabis, Ischemic Stroke and Transient Ischemic Attack: A Case Control Study
Background: Cannabis is the most widely used illicit drug of abuse. A temporal relationship between cannabis use and stroke has been reported in case series and population based studies. To date this relationship has not been confirmed. We performed a case-controlled study on the recent use of cannabis in younger stroke patients.
Methods: Consecutive ischemic stroke/TIA patients aged 18-55 years had urine screens for cannabis. A control cohort of age, sex and ethnicity matched hospital patients were screened for cannabis using anonymized urine samples obtained for other indications and which would otherwise be discarded. The study was performed with the approval of the regional Ethics Committee.
Results: One hundred and sixty of 218 (73%) ischemic stroke/TIA patients had urine drug screens [100 men, 60 women; mean (SD) age 44.8 (8.7) years], of whom 150 (94%) had ischemic stroke and 10 (6%) had TIA. Fifty-eight patients did not have drug screens, mainly because they were admitted outside office hours or had been discharged early (primarily TIA patients). All of the patients approached to provide a urine sample agreed to do so. Twenty-five (15.6%) patients had positive cannabis drug screens, and these patients were more likely to be male (84% versus 59%, χ2 p=0.016) and tobacco smokers (88% versus 28%, χ2 p<0.001). There were no differences in age, stroke mechanism or most vascular risk factors between those with and without positive cannabis tests. Control urine samples were obtained from 160 patients matched for age (t-test, p=0.979), sex (χ2 p=0.492) and ethnicity (χ2 p=0.910). Thirteen (8.1%) control participants tested positive for cannabis. In a logistic regression analysis adjusted for age, sex and ethnicity, cannabis use was associated with increased risk of ischemic stroke and TIA (odds ratio 2.30, 95% confidence intervals 1.07-4.95).
Conclusions: This study provides the strongest evidence to date of an association between cannabis and stroke, with ischemic stroke and TIA patients twice as to have recently used cannabis likely as control participants. Cannabis is generally perceived as having few serious adverse effects. This study suggests that this may not be the case and that the association between cannabis and stroke warrants further investigation.
- © 2012 by American Heart Association, Inc.