What Cardiologists Should Know About Marijuana and Heart Risk
Case reports and temporal associations link marijuana inhalation to heart attacks, sudden cardiac death, stroke, and arterial disease, though controlled studies confirming causation are lacking.
Quick Facts
What This Study Found
The review documents temporal associations between marijuana use and several serious cardiovascular events: myocardial infarction (heart attack), sudden cardiac death, cardiomyopathy, stroke, transient ischemic attack, and cannabis arteritis (inflammation of blood vessels).
Marijuana is known to cause tachycardia (rapid heart rate), which could trigger cardiovascular events in vulnerable individuals. It also causes peripheral vasodilation, which can affect blood pressure and cardiac workload.
The authors emphasize that approximately 200 million people use marijuana worldwide, and as decriminalization and legalization expand, cardiologists should expect to encounter these potential complications more frequently. However, they note that the evidence is primarily based on case reports and temporal associations rather than controlled studies.
Key Numbers
Approximately 200 million marijuana users worldwide. Documented associations: myocardial infarction, sudden cardiac death, cardiomyopathy, stroke, TIA, cannabis arteritis.
How They Did This
This is a brief narrative review focused on cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation. The authors reviewed case reports, case series, and available epidemiological data linking marijuana use to adverse cardiovascular events.
Why This Research Matters
With expanding marijuana legalization, cardiologists need to be aware of potential cardiovascular risks, particularly for patients with pre-existing heart conditions. The review serves as a clinical alert for a risk that may increase in prevalence as marijuana use becomes more widespread.
The Bigger Picture
The cardiovascular effects of marijuana are less studied than its neuropsychiatric effects but may be clinically significant, particularly for older users or those with pre-existing cardiovascular disease. As the demographics of cannabis use shift with legalization, cardiovascular risks may become more apparent.
What This Study Doesn't Tell Us
The evidence is primarily from case reports and temporal associations, which cannot prove causation. The incidence of cardiovascular events attributable to marijuana is unknown. Many reported cases involved young people where other risk factors may have been present. Dose-response relationships have not been established.
Questions This Raises
- ?What is the actual incidence of marijuana-associated cardiovascular events?
- ?Are edibles safer than smoked cannabis for cardiovascular risk?
- ?Should patients with heart disease be specifically counseled about marijuana?
Trust & Context
- Key Stat:
- Temporal associations documented between marijuana and MI, sudden cardiac death, stroke, and arteritis
- Evidence Grade:
- This is a narrative review of primarily case reports and temporal associations. Controlled studies confirming cardiovascular causation are lacking.
- Study Age:
- Published in 2014. Larger epidemiological studies on cannabis and cardiovascular risk have been published since, with ongoing investigation.
- Original Title:
- Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know.
- Published In:
- The American journal of cardiology, 113(1), 187-90 (2014)
- Authors:
- Thomas, Grace, Kloner, Robert A(2), Rezkalla, Shereif
- Database ID:
- RTHC-00880
Evidence Hierarchy
Summarizes existing research on a topic.
What do these levels mean? →Frequently Asked Questions
How does marijuana affect the heart?
Marijuana causes tachycardia (increased heart rate) and peripheral vasodilation (widening of blood vessels). The increased heart rate can place additional demand on the heart, potentially triggering events in people with existing cardiovascular disease.
Are young people at risk for marijuana-related heart problems?
Most reported cases involved young people, which is notable because cardiovascular events are rare in this age group. However, the absolute risk appears to be very low, and these cases may represent rare events in individuals with unrecognized vulnerabilities.
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Cite This Study
https://rethinkthc.com/research/RTHC-00880APA
Thomas, Grace; Kloner, Robert A; Rezkalla, Shereif. (2014). Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know.. The American journal of cardiology, 113(1), 187-90. https://doi.org/10.1016/j.amjcard.2013.09.042
MLA
Thomas, Grace, et al. "Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know.." The American journal of cardiology, 2014. https://doi.org/10.1016/j.amjcard.2013.09.042
RethinkTHC
RethinkTHC Research Database. "Adverse cardiovascular, cerebrovascular, and peripheral vasc..." RTHC-00880. Retrieved from https://rethinkthc.com/research/thomas-2014-adverse-cardiovascular-cerebrovascular-and
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.