What are the risks of marijuana use in individuals with cardiovascular disease (CVD)?

From the Guidelines

Marijuana use should be avoided in individuals with cardiovascular disease due to its potential to increase the risk of adverse cardiovascular events. The active compounds in marijuana, particularly THC, can cause increased heart rate (tachycardia), elevated blood pressure, and reduced blood flow to the heart, which can trigger angina, heart attacks, arrhythmias, and even sudden cardiac death in vulnerable patients 1. According to the 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA guideline for the management of patients with chronic coronary disease, patients with cardiovascular disease should be routinely asked and counseled about substance use, including marijuana, to reduce the risk of adverse cardiovascular events 1.

Key Risks and Considerations

• Marijuana smoke contains many of the same harmful chemicals as tobacco smoke, promoting inflammation and atherosclerosis, which can further increase the risk of cardiovascular disease 1.
• The risk of cardiovascular events is especially pronounced in the first hour after smoking marijuana, when heart attack risk may increase up to five times.
• Edible forms of marijuana are not necessarily safer, as they can produce unpredictable and sometimes more intense cardiovascular effects.
• Patients with pre-existing conditions like coronary artery disease, heart failure, or arrhythmias face the highest risk when using marijuana.

Recommendations for Patients with CVD

• Patients with CVD should have a thorough discussion with their cardiologist before considering marijuana for medical purposes to weigh potential benefits against the significant cardiovascular risks 1.
• Alternative treatments with better safety profiles should be explored for patients with CVD who are considering marijuana for medical purposes.
• Limiting or avoiding marijuana use altogether is recommended to reduce the risk of adverse cardiovascular events in individuals with CVD 1.

From the Research

Risks of Marijuana Use in Individuals with Cardiovascular Disease (CVD)

• Marijuana use has been associated with an increased risk of myocardial infarctions (MIs) in young male patients, with a 4.8-fold increase in the risk of MI onset within 60 minutes after marijuana consumption 2.
• Smoking marijuana has been shown to increase the annual risk of MI in daily cannabis users from 1.5% to 3% per year 2.
• The use of marijuana may trigger cardiovascular events, such as myocardial infarction, cardiac arrhythmias, cardiomyopathies, stroke, and arteritis, particularly in young, healthy individuals with no prior cardiovascular risk factors 3.
• Marijuana use has been linked to coronary arterial vasospasm, which may contribute to the increased risk of cardiovascular events 2.

Cardiovascular Considerations and Pharmacological Interactions

• Cannabinoid receptors are distributed in multiple tissue beds and cells, including platelets, adipose tissue, and myocytes, which may contribute to the adverse cardiovascular effects of marijuana use 4.
• Marijuana use may interact with other medications, such as anticoagulants and antiplatelet agents, which may increase the risk of bleeding or other cardiovascular complications 4.
• The potency of marijuana has increased over the past decade, which may contribute to a higher risk of adverse cardiovascular events 3.

Epidemiological Studies and Associations

• A retrospective study using the Behavioral Risk Factor Surveillance System (BRFSS) database found no significant association between marijuana use and cardiovascular disease in US adults, although the study had limitations due to missing data 5.
• A systematic review of the literature found insufficient data to conclude whether marijuana use has a negative impact on long-term cardiovascular health 5.
• Observational data suggest associations between marijuana use and a broad range of adverse cardiovascular risks, including myocardial infarction, stroke, and cardiac arrhythmias 4.

Clinical Implications and Recommendations

• Clinicians should be aware of the potential cardiovascular risks associated with marijuana use, particularly in individuals with pre-existing cardiovascular disease 2, 4.
• Screening for marijuana use is encouraged, especially in young patients presenting with cardiovascular disease 4.
• Further research is needed to definitively determine the impact of marijuana on cardiovascular disease and to provide clearer guidance regarding its cardiovascular safety 2, 4.