Marijuana Use May Increase Risk of Heart Attack and Stroke, Review of 16 Studies Suggests | Research

The takeaway

A systematic review of 16 studies found marijuana use was associated with increased risk of heart attack within 24 hours of use and stroke, especially among people with existing cardiovascular conditions.

Cannabis users with cardiovascular risk factors and healthcare providers managing patients who use cannabis

16 studies reviewed

What the researchers found

Marijuana use was associated with an increased likelihood of heart attack within 24 hours in 2 studies and stroke in 6 studies. Results also suggested increased risk for angina and acute coronary syndrome, particularly among people with a history of cardiovascular events.

Why it matters

As marijuana use increases and perceived risk decreases, understanding cardiovascular effects becomes more important. The association with acute events like heart attack and stroke within hours of use suggests a time-sensitive physiological mechanism.

The numbers in context

16 studies included from 3,916 citations; 2 studies linked use to heart attack within 24 hours; 6 studies linked use to stroke; study sizes ranged from 10 to 118,659,619 hospitalizations

How the study worked

Systematic review searching six databases from 1970 to 2018. Of 3,916 citations, 16 met inclusion criteria. Included 4 cohort studies, 8 case-control studies, 1 case-crossover study, 2 RCTs, and 1 descriptive study. Study sizes ranged from 10 participants to over 118 million hospitalizations.

What this study cannot tell us

Most studies were observational, limiting causal conclusions. Cannabis use was measured differently across studies (self-report, diagnostic codes, drug tests). Potential confounding by tobacco co-use was not always controlled. Search ended in 2018, missing more recent studies.

How to read the evidence

Systematic review with broad database search, but mostly observational studies with heterogeneous methods and potential confounding

When this study was published

2022 study

The bigger picture

Cardiovascular risk from cannabis use is less studied than respiratory or cognitive effects. As the population of cannabis users ages and more people use cannabis while managing existing heart conditions, these associations become increasingly relevant to public health.

Questions still open

What is the biological mechanism behind cannabis-related cardiovascular events? Does the method of consumption (smoking vs edibles) affect cardiovascular risk? Are certain cannabinoids more cardiotoxic than others?

Common questions

Can marijuana cause a heart attack?

This review found an association between marijuana use and heart attack risk, particularly within 24 hours of use. However, the observational study designs cannot definitively prove marijuana caused the events.

Are people with heart disease at higher risk from cannabis?

The review suggested that people with a history of cardiovascular events may face higher risk for angina and acute coronary syndrome with marijuana use, though more research is needed.

Read the original research

Nonmedical Marijuana Use and Cardiovascular Events: A Systematic Review.

Public health reports (Washington, D.C. : 1974), 137(1), 62-71

View on PubMed ↗Publisher’s paper ↗

Citation

Yang, Peter K; Odom, Erika C; Patel, Roshni; Loustalot, Fleetwood; Coleman King, Sallyann. (2022). Nonmedical Marijuana Use and Cardiovascular Events: A Systematic Review.. Public health reports (Washington, D.C. : 1974), 137(1), 62-71. https://doi.org/10.1177/0033354920988285