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Frequent Marijuana Use Doubles Myocardial Infarction Risk


Am J of Medicine 2021; 134: 614-20

Study Summary

Observational voluntary survey study using the Behavioral Risk Factor Surveillance System of 133,00+ patients found adults (18-74) that are frequent marijuana users (>/= 10 days out of last 30 days) had increased odds of MI (aOR = 1.88; CI: 1.15-3.08) and increased odds of stroke (aOR=1.81; CI: 1.14-2.89). For younger patients (Male < 55 years; Women < 65 years), frequent marijuana use increased odds further; for MI/CAD (aOR=2.27; CI: 1.20-4.30) and for stroke (aOR=1.92; CI 1.07-3/43). This risk was only present for those who smoked marijuana, but not for other forms of marijuana use.


Smoking marijuana on 10 or more days per month increases odds of MI and CVA for patients, but especially so for those at younger ages.


This is an observational study from a survey of over 400,000 adults. Participation was voluntary, and their answers to questions like: "has a doctor, nurse or other health care professional told you that you had a myocardial infarction or coronary heart disease?" was not further substantiated by medical records. Nonetheless, this is very concerning data.

Nicotine causes coronary artery vasospasm, but there is no overt data showing smoking marijuana does the same. But, it may; additionally vasculitis, acute hypotension (inducing vasospasm) or blood flow dysregulation are proposed mechanisms of action.

Data from a 2019 systematic review showed similar outcomes (Clin Toxicol 2019; 57(10): 831) and a 2018 observational study showing regular marijuana use increased CV and all-cause mortality risk (J Am Coll Cardiol 2018; 71(22): 2540).

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