Real-world data captures risk of major cardiac events with cannabis use

Cannabis users are at increased risk of major adverse cardiovascular events (MACE), according to the results of a meta-analysis based on real-world data.

Pooled data from 24 pharmacoepidemiological studies involving more than 400 million individuals showed cannabis use to be associated with a 1.2-to-1.3–fold higher risk of stroke (risk ratio [RR], 1.20, 95 percent confidence interval [CI], 1.13–1.26) and acute coronary syndrome (RR, 1.29, 95 percent CI, 1.05–1.59) and a twofold higher risk of cardiovascular death (RR, 2.10, 95 percent CI, 1.29–3.42). [Heart 2025;doi:10.1136/heartjnl-2024-325429]

Of the studies included in the meta-analysis, 17 were cross-sectional, six were cohort, and one was case-control. Altogether, these studies included a total of 432,245,972 participants (mean age range, 19–59 years). Cannabis users were mostly male (54 percent to 100 percent) and more likely to be younger compared with nonusers.

A sensitivity analysis restricted to cohort studies yielded consistent results.

The investigators acknowledged that heterogeneity between studies was substantial to considerable, with I² values ranging between 79.2 percent and 89.3 percent. Furthermore, they noted that cannabis exposure was poorly reported in the included studies, and this prevented its assessment in the meta-analysis.

Nevertheless, “these findings should enhance the general awareness of the potential of cannabis to cause cardiovascular harm [as well as] encourage investigating cannabis use in all patients presenting with serious cardiovascular disorders,” the investigators said.

They pointed out that the evidence linking cannabis use to the risk of MACE is further supported by findings from recent studies, including those from France and the US. Specifically, independent associations were observed between cannabis and in-hospital MACE and between daily cannabis use and MI, stroke, and the composite of coronary heart disease, MI, and stroke. [Arch Cardiovasc Dis 2022;115:514-520; Heart 2023;109:1608-1616; J Am Heart Assoc 2024;13:e030178]

An important risk factor

In a linked editorial, Drs Stanton Glant and Lynn Silver, both from the University of California San Francisco in San Francisco, California, US, stressed that cannabis should now be regarded as an important risk factor for cardiovascular disease. [Heart 2025;doi:10.1136/heartjnl-2025-326169]

“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,” Glant and Silver said.

The call comes as legalization of medical and recreational cannabis commerce is spreading around the world, leading to increased use and falling perception of its risk. [Int J Drug Policy 2024;134:104618; J Am Heart Assoc 2024;13:e030178]

“Frequent cannabis use has increased in several countries, and many users believe that it is a safe and natural way to relieve pain or stress,” Glant and Silver noted. “[This makes it critical that] effective product warnings and education on risks be developed, required, and implemented.”

In closing, Glant and Silver argued that cannabis ought to be treated like tobacco: “not criminalized, but actively discouraged, with [measures in place to] protect bystanders from secondhand exposure.”