(P-466) Risk of Emergency Department Visits or Hospitalization for Cardiovascular Events in Patients with Medical Cannabis Authorization

Background: Emerging evidence mainly from case reports and very few observational studies suggest that cannabis use could be associated with an increased risk of cardiovascular event.

Objectives: This study assesses the risk of CV-related emergency department (ED) visit/hospitalization in adult patients authorized to use medical cannabis in Ontario, Canada from 2014-2017.

Methods: This is a longitudinal cohort study of patients who received medical cannabis authorization and followed-up in cannabis clinics, matched to population-based controls. The primary outcome was an ED visit/hospitalization for acute coronary syndrome (ACS) or stroke; and secondary outcome was for any CV event. Conditional Cox proportional hazards regressions adjusted for prior CV events and other covariates were used to assess the association between cannabis use and risk.

Results: 18,653 cannabis patients were matched to 5,1243 controls for a median follow-up of 240 days. Incidence rates for ACS or stroke were 7.19/1000 person-years and 5.67/1000 person-years in the cannabis and controls group, respectively- adjusted hazard ratio (aHR) of 1.44 (95%CI: 1.08-1.93). When stratified by sex, the association was only statistically significant among males: aHR 1.77 (1.23-2.56).
For the secondary outcome (any CV events), the aHR was 1.47 (1.26-1.72). The aHR among males and females were 1.52 (1.24-1.86) and 1.41 (1.11 -1.79), respectively. Tested interactions between cannabis authorization and sex were not significant.

Conclusions: Medical cannabis authorization was associated with an increased risk of ED visits or hospitalization for ACS/stroke and any CV event. No difference was observed between male and female.