Medical Cannabis Patients Had 15% Higher Risk of Heart Failure Events

Patients with authorized cannabis prescriptions had a hazard ratio of 1.15 (95% CI: 1.06-1.25) for the primary outcome of ED visits/hospitalization for heart failure. Incidence rates were 5.87 per 1000 person-years in the cannabis group vs. 5.14 in controls. The secondary outcome (including physician claims) showed a similar pattern (HR 1.13, 95% CI: 1.08-1.19).

Retrospective cohort study using Ontario health administrative and clinical data. 54,006 patients with authorized cannabis prescriptions (2014-2019) matched with 161,265 general population controls. Inverse probability of treatment weighting based on propensity scores minimized confounding.

As medical cannabis prescribing expands, understanding cardiovascular risks is essential. This is one of the largest studies linking medical cannabis to heart failure events, suggesting a modest but clinically significant increased risk that patients and prescribers should consider.

This adds to growing evidence of cardiovascular risks with cannabis use. While the 15% increased risk is modest, heart failure is a serious and costly condition. Medical cannabis patients may have underlying conditions that contribute, but the risk signal warrants monitoring.

Observational — cannot prove causation. Medical cannabis patients likely have more underlying health conditions (confounding by indication). Authorized prescription doesn't confirm actual use or dosage. Ontario-specific results may not generalize. No information on cannabis type or consumption method.