Large-Scale Study Links Cannabis Use to Increased Risk of Cardiovascular Death, Stroke

Legal in several countries, including Canada, Germany, and parts of the U.S., cannabis is used worldwide and widely promoted as a wellness product. However, as its popularity rises and more people consume it, its potential health risks are often overlooked. Now, a large systematic review strengthens evidence linking cannabis use to major adverse cardiovascular events, suggesting it should be considered a risk factor for heart disease.

Conducted by researchers from France and published in Heart, the study examined 24 pharmacoepidemiological papers (selected from an initial 3,012 records) over 7 years. The final analysis included 17 cross-sectional studies, six cohort studies, and one case-control study, with approximately 432 million participants. Cannabis use was considered the primary exposure variable in all studies, with one study focused on medical cannabis.

The researchers assessed study quality using the ROBINS-E tool (Risk of Bias in Non-Randomized Studies of Exposure). For the meta-analysis, the researchers pooled adjusted effect estimates and their 95% confidence intervals using a DerSimonian-Laird random effects model with inverse variance weighting, based on the type of outcome studied.

The meta-analysis showed an estimated 29% higher risk of acute coronary syndrome (ACS) among cannabis users (RR 1.29; 95% CI: 1.05–1.59), 20% higher risk of stroke (RR 1.20; 95% CI: 1.13–1.26) and 2.1 fold (210%) higher risk of cardiovascular death (RR 2.10; 95% CI: 1.29–3.42). However, the authors found no statistically significant association for the combined outcome of stroke and ACS.

The authors acknowledged the study’s limitations, including the inability to establish causation and the lack of precise exposure measurements, as most data were observational with reliance on self-reported cannabis use. Nonetheless, they emphasized that using real-world data provides valuable insight into current patterns of cannabis use and associated heart health risks in the population today.

The researchers concluded that findings from the study should encourage clinicians to note the cardiovascular disease risks of cannabis use and “investigate such use in all patients presenting with serious cardiovascular disorders.”