Setareh Salehi Omran, MD
International Stroke Conference 2021
March 17–19, 2021
Session: Substance Abuse in Stroke (153, OnDemand)
The session “Substance Abuse in Stroke” at the International Stroke Conference 2021 included several presentations on the risk of stroke from a wide range of substances, including cannabis, tobacco cigarettes, e-cigarettes, alcohol, methamphetamine, and cocaine.
Marijuana and Synthetic Cannabinoid by Dr. Stephen Sidney:
Dr. Sidney discussed the potential mechanisms of cerebrovascular disease associated with cannabis use. Cannabis can lead to cerebrovascular disease through direct toxic effects on the vascular bed, altered hemodynamics (increased heart rate, increased supine blood pressure, postural hypotension), incident atrial fibrillation and atrial flutter, and endothelial dysfunction. Several studies have shown an association between cannabis exposure and increased risk of stroke. However, these studies have several major limitations, including cross-sectional study design, inability to stratify analysis by confounders (cigarette smoking, cocaine use), and lack of granular clinical information pertaining to the stroke and cannabis use (dose, composition, possible contaminants, various modes of consumption).
As it stands, it is unclear whether cannabis use is associated with stroke. It is important for clinicians to notify patients of limited data on cannabis use and stroke risk, and to advise against cannabis use in patients with known cardiovascular disease.
Smoking, Vaping, and Alcohol by Dr. Sharon Poisson:
Dr. Poisson covered the various ways in which smoking, vaping, and alcohol are associated with stroke. Smoking causes stroke through vasomotor dysfunction, activation of inflammatory pathways, alterations in balance of antithrombotic/prothrombotic factors, and increase in lipid peroxidase. Ultimately, these changes lead to a procoagulant state and acceleration of atherosclerosis. Current smoking and higher doses both contribute to increased stroke risk. Former smokers seem to have a lower risk of stroke, as the procoagulant state associated with smoking reverses days after quitting. An analysis done using data from the Framingham study showed that risk of stroke in former smokers was similar to that of never-smokers after 5 years of abstinence.
Unlike the clear link between combustible cigarette smoking and stroke, the long-term cardiovascular effects of e-cigarettes are less clearly defined. E-cigarettes are thought to increase the risk of cardiovascular disease due to the known effects of nicotine, including increased blood pressure and heart rate, increased myocardial contractility, and the lesser defined effects of inflammation, thrombosis, and endothelial dysfunction. While the data is limited, a cross sectional study showed that sole e-cig users have no increased risk of stroke compared to non-smokers, and lower risk of stroke compared to current combustible cigarette users. Current e-cigarette users who were former combustible cigarette users have an increased risk of stroke compared to non-smokers, while dual users (those that use both e-cigarettes and combustible cigarettes) had higher risk of stroke compared to sole combustible cigarette users.
Studies show that heavy alcohol consumption is associated with increased risk of cardiovascular events while data on moderate alcohol use is a bit more controversial. Overall, the studies suggest that moderate consumption of alcohol (up to 3 drinks a day in men and 1 drink a day in women) seems protective for ischemic stroke and slightly detrimental or neutral for hemorrhagic stroke.
Methamphetamine and Cocaine by Dr. Julia Lappin:
Dr. Lappin discussed the current available data on psychostimulant use, particularly methamphetamine and cocaine, and risk of stroke. Methamphetamine use leads to a five-fold increased risk of hemorrhagic stroke in young individuals, a risk twice that conferred by either cocaine or tobacco use. These strokes are also associated with increased mortality, with subarachnoid hemorrhages from methamphetamine use having a particularly poor outcome. There does not appear to be an increased risk of ischemic stroke with methamphetamine use. Cocaine use is associated with an increased risk of hemorrhagic and ischemic stroke. Importantly, the risk of stroke from psychostimulant use is not associated with mode of consumption, but more due to the substances themselves.
Chronic use of psychostimulants increases the risk of stroke by causing systemic hypertension and vessel damage with appearance in keeping with accelerated atherosclerosis. Additionally, chronic use increases the risk of both arteriovenous malformation and aneurysm rupture, with studies showing methamphetamine users are at an increased risk of aneurysmal rupture at a smaller size than what is typically seen in nonusers. This may be due to resulting physiological vascular fatigue through hypertension and tachycardia, ultimately increasing the risk for vessel rupture and aneurysm development.