Cannabis Use and Outcomes in Patients With Aneurysmal Subarachnoid Hemorrhage

Background and Purpose - The incidence of cannabis use in patients with aneurysmal subarachnoid hemorrhage (aSAH) and its impact on morbidity, mortality, and outcomes are unknown. Our objective was to evaluate the relationship between cannabis use and outcomes in patients with aSAH. Methods - Records of consecutive patients admitted with aSAH between 2010 and 2015 were reviewed. Clinical features and outcomes of aSAH patients with negative urine drug screen and cannabinoids-positive (CB+) were compared. Regression analyses were used to assess for associations. Results - The study group consisted of 108 patients; 25.9% with CB+. Delayed cerebral ischemia was diagnosed in 50% of CB+ and 23.8% of urine drug screen negative patients (P=0.01). CB+ was independently associated with development of delayed cerebral ischemia (odds ratio, 2.68; 95% confidence interval, 1.03-6.99; P=0.01). A significantly higher number of CB+ than urine drug screen negative patients had poor outcome (35.7% versus 13.8%; P=0.01). In univariate analysis, CB+ was associated with the composite end point of hospital mortality/severe disability (odds ratio, 2.93; 95% confidence interval, 1.07-8.01; P=0.04). However, after adjusting for other predictors, this effect was no longer significant. Conclusions - We offer preliminary data that CB+ is independently associated with delayed cerebral ischemia and possibly poor outcome in patients with aSAH. Our findings add to the growing evidence on the association of cannabis with cerebrovascular risk.