Cannabis use disorder may raise the risk of a heart attack or stroke

People with cannabis use disorder have an increased risk of heart attack, stroke and other major cardiovascular conditions, suggesting that frequent cannabis use may impair heart health.

Anees Bahji at the University of Calgary in Canada and his colleagues analysed the health records of  59,528 people living in Canada. Half of the participants had been diagnosed with a cannabis use disorder – which is when someone continues to use marijuana despite it disrupting their life – between January 2012 and December 2019. They then tracked who experienced a heart attack, stroke or developed another major cardiovascular condition during this period.

After adjusting for factors such as age, gender and socioeconomic status, the researchers found that people with cannabis use disorder had a nearly 60 per cent higher risk of subsequently developing a cardiovascular condition than people without it. The risk worsened with the severity of the disorder. For instance, people who sought care for cannabis dependence five or more times were over twice as likely to later have a heart or vascular problem than people without cannabis use disorder.

These findings suggest frequent cannabis use could harm heart health, though the exact mechanisms driving this association are unclear, says Bahji. It may be due to compounds in the drug, such as tetrahydrocannabinol, or THC, binding to receptors in the body. This can elevate heart rate, decrease blood pressure and impact blood clotting, Bahji says.

Cannabis use has been increasing in recent years, especially among young people. Because this study focused solely on those with cannabis use disorder, it doesn’t capture people who use the drug infrequently, says Jennifer Bailey at the University of Washington. “I would really like to see studies looking at how lower levels and short durations of cannabis use relate to heart health,” she says. “Or whether different cannabis products are differently related to heart health.”