Young men who tested positive for cannabis had more severe heart attacks and worse cardiac findings than drug-free patients | Research

The takeaway

Among men under 40 with heart attacks, those who tested positive for cannabis had more ST-elevation heart attacks, more wall motion abnormalities, and no normal coronary arteries, even though they had no other cardiac risk factors besides smoking.

Read this if you want to understand the potential cardiac risks of cannabis use in young adults.

47.8% of cannabis-positive patients had wall motion abnormalities vs 11.8% of drug-free patients

What the researchers found

Among 138 young men (age 40 or under) admitted with acute heart attacks, 23 tested positive for cannabis only. Despite having no traditional cardiac risk factors besides tobacco smoking, cannabis-positive patients showed more severe cardiac presentations.

ST-elevation myocardial infarction (STEMI, the more severe type) was dominant in the cannabis group, while non-STEMI was more common in drug-free patients. Cannabis-positive patients had ischemic wall motion abnormalities (areas of the heart not moving properly) in 47.8% of cases versus 11.8% of drug-free patients.

Strikingly, none of the cannabis-positive patients had normal coronary arteries, whereas 14.3% of drug-free patients did. Significant differences in echocardiography and angiography were observed.

Why it matters

Young people generally have very low rates of heart attack. Finding that cannabis-positive young men had more severe cardiac presentations despite fewer traditional risk factors suggests that cannabis may be an independent cardiac risk factor. The Egyptian context is important because cannabis use patterns differ from Western countries.

The numbers in context

Cannabis-only patients (n=23): STEMI dominant, 47.8% wall motion abnormalities, 0% normal coronaries. Drug-free patients (n=34): NSTEMI dominant, 11.8% wall motion abnormalities, 14.3% normal coronaries. All patients: male, age 40 or younger.

How the study worked

Cross-sectional study of 138 male patients aged 40 or younger with acute myocardial infarction admitted to a university hospital cardiac care unit in Egypt. Patients were divided by urine toxicology: cannabis-only (n=23), other substances (n=28), and negative (n=34). Cardiac evaluation included echocardiography and coronary angiography.

What this study cannot tell us

Small sample from a single hospital in Egypt. Cross-sectional design cannot prove cannabis caused the heart attacks. Urine testing detects cannabis use within days, not necessarily acute intoxication at the time of the event. Tobacco smoking was common across groups and is itself a cardiac risk factor. The cannabis products used in Egypt may differ in composition from those elsewhere.

How to read the evidence

Small cross-sectional study from a single hospital. Identifies concerning patterns but cannot establish causation.

When this study was published

Published in 2017. Cannabis and cardiovascular risk has become an increasingly studied topic.

The bigger picture

Cannabis can acutely increase heart rate and blood pressure and has been associated with coronary vasospasm (temporary artery narrowing). This study suggests these effects may be clinically significant enough to trigger heart attacks in young men, even without the diabetes, hypertension, and obesity that typically cause cardiac events.

Questions still open

Does the type of cannabis or route of consumption affect cardiac risk? Is the mechanism vasospasm, accelerated atherosclerosis, or something else? Would the same patterns be seen in a larger, multi-center study?

Common questions

Can cannabis cause a heart attack?

This study found that young men who tested positive for cannabis had more severe heart attacks and worse cardiac findings than drug-free patients, even without traditional risk factors. While this does not prove causation, it raises concern that cannabis may be a cardiac risk factor, possibly through vasospasm or other acute effects on the heart.

Why were these young men having heart attacks?

Heart attacks in men under 40 are uncommon and often result from unusual causes. The study found that cannabis-positive patients had no risk factors besides smoking, suggesting that cannabis may have contributed to their cardiac events through mechanisms different from typical atherosclerotic heart disease.

Read the original research

Marijuana use in acute coronary syndromes.

The American journal of drug and alcohol abuse, 43(5), 576-582

View on PubMed ↗Publisher’s paper ↗

Citation

Draz, Eman I; Oreby, Mervat M; Elsheikh, Eman A; Khedr, Lamia A; Atlam, Salwa A. (2017). Marijuana use in acute coronary syndromes.. The American journal of drug and alcohol abuse, 43(5), 576-582. https://doi.org/10.1080/00952990.2016.1240800