Cannabis use may double risk of cardiovascular disease death

Cannabis use has been linked to a doubling in the risk of dying from cardiovascular disease, with significantly heightened risks of having a stroke or acute coronary syndrome (sudden reduced or blocked blood flow to the heart). That’s according to a pooled analysis of real-world data, published in the journal Heart.

Researchers at the University of Toulouse noted that the use of cannabis and cannabinoids has soared over the past decade, with its legalisation in certain jurisdictions and expanded use for medicinal purposes no doubt helping to drive its growing popularity. But while previously published studies have linked cannabis use to cardiovascular problems, the magnitude of the risk hasn’t been clear — which is concerning in light of major changes in consumption and the increased potency of the drug.

To strengthen the evidence base, the researchers scoured research databases looking for large observational studies, published between January 2016 and December 2023, which explored cannabis use and serious cardiovascular outcomes. From an initial haul of 3012 articles, 24 studies involving around 200 million people (mostly aged between 19 and 59) were included in a pooled data analysis of the results; this included 17 cross-sectional studies, six cohort studies and one case-control study. The analysis revealed that cannabis users had a 29% higher risk of acute coronary syndrome, a 20% higher risk of stroke, and a doubled risk of dying from cardiovascular disease.

The researchers acknowledge that there was a moderate to high risk of bias in most of the included studies, largely because of lack of information on missing data and imprecise measures of cannabis exposure. Most of the included studies were observational, precluding the ability to draw causal inferences from the data, while several used the same data.

Notwithstanding these caveats, the researchers say that theirs is an exhaustive analysis of published data on the potential association between cannabis use and major cardiovascular disease and provides new insights from real-world data. Their findings are further explored in a linked editorial, by Emeritus Professor Stanton Glantz and Dr Lynn Silver from the University of California, San Francisco, who said the study “raises serious questions about the assumption that cannabis imposes little cardiovascular risk”.

According to Glantz and Silver, more research is clearly needed to clarify whether cardiovascular risks are limited to inhaled products or extend to other forms of cannabis exposure. This is because cannabis has now diversified into a wide array of inhaled high-potency cannabis concentrates, synthetic psychoactive cannabinoids, and edibles.

“How these changes affect cardiovascular risk requires clarification, as does the proportion of risk attributable to cannabinoids themselves versus particulate matter, terpenes or other components of the exposure,” the editorial authors said.

“Cannabis needs to be incorporated into the framework for prevention of clinical cardiovascular disease. So too must cardiovascular disease prevention be incorporated into the regulation of cannabis markets. Effective product warnings and education on risks must be developed, required and implemented.

“Cardiovascular and other health risks must be considered in the regulation of allowable product and marketing design as the evidence base grows. Today that regulation is focused on establishing the legal market with woeful neglect of minimising health risks.

“Specifically, cannabis should be treated like tobacco: not criminalised, but discouraged, with protection of bystanders from second-hand exposure.”

Image credit: iStock.com/Rouzes