Heart attack in a 21-year-old cannabis user with completely normal arteries | Research

The takeaway

A 21-year-old regular cannabis user had a heart attack with a large blood clot in a coronary artery, but intravascular ultrasound confirmed his arteries were completely free of atherosclerosis.

Read this if you use cannabis and want to understand the rare but serious cardiovascular risks.

Heart attack in a 21-year-old with zero atherosclerosis confirmed by ultrasound

What the researchers found

A previously healthy 21-year-old man who regularly smoked cannabis presented with an ST-elevation myocardial infarction (the most serious type of heart attack) during sports activity. Coronary angiography revealed a large thrombus (blood clot) in the left anterior descending coronary artery.

The unique contribution of this case was the use of intravascular ultrasound to definitively exclude atherosclerotic plaque rupture as the cause. The arteries were completely normal, ruling out the most common mechanism of heart attack in older patients. The only cardiovascular risk factors were cannabis and cigarette smoking.

This was described as the first report where atherosclerotic plaque rupture was excluded with high confidence using intravascular imaging in a cannabis-associated heart attack.

Why it matters

By ruling out atherosclerosis, this case pointed to alternative mechanisms by which cannabis might trigger heart attacks, such as vasospasm, direct prothrombotic effects, or endothelial dysfunction. Understanding the mechanism is critical for assessing who is at risk.

The numbers in context

One patient, age 21. ST-elevation MI during sports. Large thrombus in left anterior descending artery. Intravascular ultrasound: no atherosclerosis at thrombus site.

How the study worked

Single case report with coronary angiography and intravascular ultrasound imaging to characterize the coronary pathology and definitively exclude atherosclerosis.

What this study cannot tell us

Single case report. The patient also smoked cigarettes, which is an independent cardiovascular risk factor. Cannot definitively prove cannabis caused the event. Case reports cannot establish incidence rates.

How to read the evidence

Single case report with advanced imaging. Novel finding but limited to one patient.

When this study was published

Published in 2014.

The bigger picture

Cannabis-associated heart attacks in young people with normal arteries challenge the traditional model where heart attacks require pre-existing coronary artery disease. If cannabis can trigger thrombosis in healthy arteries, the at-risk population may be broader than previously thought.

Questions still open

What is the mechanism by which cannabis triggers thrombosis in healthy arteries? Does the combination of cannabis and vigorous exercise increase risk? How common is this event among young cannabis users?

Common questions

Can you have a heart attack from cannabis if your arteries are healthy?

This case suggests yes. A 21-year-old with no atherosclerosis (confirmed by intravascular ultrasound) had a heart attack with a blood clot in a coronary artery. The mechanism may involve vasospasm or direct clotting effects rather than plaque rupture.

How rare is a cannabis-related heart attack?

Case reports like this are uncommon, and the actual incidence is unknown. Most cannabis users will never experience this, but the fact that it can occur in young people with no other risk factors is noteworthy.

Read the original research

Cannabis-associated myocardial infarction in a young man with normal coronary arteries.

The Journal of emergency medicine, 47(3), 277-81

View on PubMed ↗Publisher’s paper ↗

Citation

Hodcroft, Christopher J; Rossiter, Melissa C; Buch, Ashesh N. (2014). Cannabis-associated myocardial infarction in a young man with normal coronary arteries.. The Journal of emergency medicine, 47(3), 277-81. https://doi.org/10.1016/j.jemermed.2013.11.077