Cannabis Use Disorder Substantially Increases Risk for Cardiovascular Events

Individuals with cannabis use disorder (CUD) have an approximately 60% higher risk of experiencing incident adverse cardiovascular disease (CVD) events relative to those without CUD, according to study findings published in Addiction.

Cannabis use has increasingly been associated with a wide range of adverse health outcomes. Particularly, there has been an appreciable amount of research exploring the relationship between CUD and CVD events. However, this relationship is still unclear given the conflicting findings reported in the literature thus far. To further the understanding of cardiovascular outcomes and cannabis use, investigators conducted a comprehensive, population-based study.

The investigators examined longitudinal data, collected between January 2012 and December 2019, from multiple databases maintained by the Alberta Ministry of Health. Patients with CUD were identified using International Classification of Diseases (ICD) codes and control patients were matched on age, gender, and time of health service utilization. The primary outcome of the study was an incident CVD event over the course of the study period. The investigators included acute myocardial infarction, unstable angina, other ischemic heart disease, ischemic stroke, heart failure, cardiac dysrhythmias, or peripheral vascular disease as eligible CVD event outcomes. Patients with a previous history of CVD events were excluded.

A total of 29,764 patient pairs (n=59,528 individuals) were included in the analysis, with a 0.8% prevalence of CUD overall for Alberta. The proportion of participants experiencing at least one incident adverse CVD event was 2.4% in the CUD group vs 1.5% in the control group (risk ratio [RR], 1.57; 95% CI, 1.40-1.77). Results from log-rank testing confirmed a significant overall association between CUD and incident CVD (χ2=59.7890; P <.001). Sensitivity analysis revealed a dose-dependent increase in the strength of the association, as the risk for CVD events increased from 1.32 (95% CI, 1.22–1.43) for patients with 1 CUD diagnostic code to 2.47 (95% CI, 2.28-2.68) among those with 2 to 4 CUD codes and 2.64 (95% CI, 2.40–2.91) for those with 5 or more CUD codes.

Confounding variable analysis showed that RR estimates were higher among patients with no medical comorbidities (P =.0037), who were not on any prescriptions (P =.0116), and who had had fewer than 5 visits to health services in the last 6 months (P =.0149). Notably, E-value analyses could not exclude the possibility that an unmeasured confounder, such as cigarette smoking, could account for the association between CUD and adverse CVD events.

These findings revealed that adults with CUD had a 60% higher risk of experiencing incident adverse CVD events relative to matched individuals without CUD. Study authors concluded, “Importantly, this evidence suggests that cannabis use may place a healthier population at increased risk of major cardiovascular events.”

There are several limitations of this study. First, confounding from tobacco use was not directly controlled and the severity of CUD was not directly measured. Further, the investigators did not examine type of cannabis consumed, mode of consumption, or frequency of use. Additionally, the study presumed that patients who received a CUD diagnosis continued to use cannabis consistently throughout the study period, but did not confirm recent use.

Disclosure: Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of author disclosures.