Systematic review of 62 cases links marijuana use to heart attacks in young people with no risk factors | Research

The takeaway

A systematic review of 62 published cases found marijuana-associated heart attacks occurred at an average age of 27.7, with 37% having normal coronary arteries and 7 deaths reported.

Cardiologists, emergency medicine physicians, and young cannabis users concerned about heart health.

Average age 27.7; 37% had normal coronary arteries; 7 deaths in 62 cases

What the researchers found

Across 46 published studies describing 62 patients who had acute myocardial infarction following marijuana use, the mean age was 27.7 years with male predominance. Average onset was within 5 hours of use. Angiographic findings were normal in 36.8%, while the left anterior descending artery was the most commonly occluded vessel (42.1%). Seven deaths were reported among the 62 cases.

Why it matters

Heart attacks in people under 30 with no traditional risk factors are rare. The pattern of young, otherwise healthy users having coronary events shortly after marijuana use suggests a direct pharmacological trigger worth understanding.

The numbers in context

62 patients; mean age 27.7 (SD 10.3); ~3.7g average use; 9.7 years average use history; symptoms within 5h; normal angiogram 36.8%; LAD occlusion 42.1%; 7 deaths.

How the study worked

Systematic review of case reports, case series, and letters to the editor from MEDLINE describing individuals with acute myocardial infarction associated with marijuana use. 46 studies with 62 total patients included.

What this study cannot tell us

Case reports only (lowest level of evidence); publication bias toward unusual presentations; cannot establish causation from case series; no denominator to calculate actual risk; other substance co-use may be underreported.

How to read the evidence

Moderate: systematic methodology but entirely case-report based evidence, the lowest level of individual study quality.

When this study was published

Published 2020.

The bigger picture

With an average of 3.7g consumed over nearly 10 years, these were not one-time users. The 37% with completely normal coronary arteries suggests marijuana may cause coronary vasospasm rather than atherosclerosis, an important mechanistic distinction.

Questions still open

Is coronary vasospasm the primary mechanism? Does the route of consumption (smoking vs edibles) affect cardiovascular risk? What is the actual incidence rate among marijuana users?

Common questions

Can marijuana cause a heart attack?

This review of 62 published cases found heart attacks occurring within 5 hours of marijuana use, often in young people with no traditional cardiac risk factors. About 37% had completely normal coronary arteries, suggesting spasm rather than blockage.

How common are marijuana-related heart attacks?

Unknown. Only 62 cases have been published, but this likely underestimates the true number since not all cases are reported. The actual risk rate among marijuana users cannot be determined from case reports alone.

Read the original research

Marijuana use and acute myocardial infarction: A systematic review of published cases in the literature.

Trends in cardiovascular medicine, 30(5), 298-307

View on PubMed ↗Publisher’s paper ↗

Citation

Patel, Rikinkumar S; Kamil, Saher H; Bachu, Ramya; Adikey, Archana; Ravat, Virendrasinh; Kaur, Mandeep; Tankersley, William E; Goyal, Hemant. (2020). Marijuana use and acute myocardial infarction: A systematic review of published cases in the literature.. Trends in cardiovascular medicine, 30(5), 298-307. https://doi.org/10.1016/j.tcm.2019.08.003