Cardiovascular Risks of Cannabis Use
Cannabis use poses significant and well-documented cardiovascular risks including myocardial infarction, stroke, arrhythmias, and sudden cardiac death, with young adults who use cannabis frequently (>10 days/month) having 2.45 times higher odds of stroke compared to non-users. 1
Acute Cardiovascular Effects
Cannabis causes immediate cardiovascular stress through multiple mechanisms:
- Sympathetic nervous system activation leads to dose-dependent increases in heart rate and blood pressure, while simultaneously causing coronary vasoconstriction 2
- Increased myocardial oxygen demand can precipitate ischemic events in susceptible individuals, decreasing time to exercise-induced angina in patients with stable angina 2, 3
- Arrhythmias and orthostatic hypotension occur with acute use, creating risk for falls and syncope 4, 2
- Risk of myocardial infarction increases 4.8-fold during the 60 minutes following cannabis consumption 3
The American Heart Association reports that cannabis blocks catecholamine reuptake at presynaptic terminals, increases endothelin-1 while decreasing nitric oxide, and promotes a prothrombotic state through increased platelet activation and aggregation 4
Long-Term Cardiovascular Consequences
Chronic cannabis use is associated with serious cardiovascular events:
- Myocardial infarction and stroke are documented complications of long-term use 4, 2, 5
- Premature cardiovascular disease was independently associated with recreational cannabis use in the Veterans Affairs Healthcare database 2
- Daily cannabis users face increased annual MI risk from 1.5% to 3% per year 3
Age-Specific Risks
Young Adults (18-44 years)
- Stroke risk is particularly elevated in this population, with adjusted odds ratio of 1.82 for recent cannabis users and 2.45 for frequent users (>10 days/month) 1
- Acute ischemic stroke hospitalization is 41% higher among cannabis users (OR 1.41) 1
- Drug use was observed in 10% of patients under 50 years presenting with myocardial infarction 2
Older Adults (≥65 years)
- Higher risk for confusion, falls, and behavioral health issues including anxiety and depression 4
- Cannabis-related emergency department visits have increased, with acute toxicity potentially associated with sedation, obtundation, and myocardial ischemia or infarction 4
Mechanism of Cardiovascular Harm
The pathophysiology involves multiple pathways:
- Coronary arterial vasospasm may explain MI triggering in young patients 3
- Endothelial dysfunction and platelet activation contribute to thrombotic events 2
- Combined use with tobacco results in greater increases in heart rate and vasoconstriction than either substance alone 4
Potency Considerations
Cannabis products have become dramatically more potent, with average THC concentration nearly doubling from 9% in 2008 to 17% in 2017, and cannabis concentrates reaching THC levels as high as 70% 4. This increasing potency significantly elevates all cardiovascular health risks 4
Clinical Screening and Counseling Recommendations
The American College of Cardiology provides clear guidance:
- Patients with chronic coronary disease should be routinely asked and counseled about cannabis use to reduce atherosclerotic cardiovascular disease events 2
- Screening is especially important in young patients presenting with cardiovascular disease 2
- Patients with cardiovascular disease should not be advised to consume cannabis for cardiovascular protection, as medical marijuana has not been FDA-approved for cardiovascular indications 2
Critical Pitfall to Avoid
Despite legalization trends and public perception of safety, the cardiovascular risks are real and well-established 4, 6, 2. The benefits have not been proven for cardiovascular conditions, while the risks—including psychiatric harms, substance use disorder, cardiovascular events, and impaired functioning—are documented 6. Healthcare providers must communicate these risks clearly, particularly to young patients and those with existing cardiovascular disease or risk factors.