As global cannabis consumption continues to rise amid shifting social norms and policy reforms, growing attention is being paid to its potential health implications—particularly its effects on cardiovascular health. A systematic review and meta-analysis published in Heart offers one of the most comprehensive evaluations to date on the link between cannabis use and major adverse cardiovascular events (MACE), which include non-fatal stroke, non-fatal acute coronary syndrome (ACS), and cardiovascular death.
The study analyzed 24 pharmacoepidemiological studies published between January 2016 and January 2023. These included over 432 million patient records from large databases such as the National Inpatient Sample (NIS), the Behavioral Risk Factor Surveillance System (BRFSS), and the National Health and Nutrition Examination Survey (NHANES). The majority examined recreational cannabis use; only one focused on medical cannabis.
Cannabis use was associated with a 29% increased risk of acute coronary syndrome (RR=1.29), a 20% increased risk of stroke (RR=1.20), and a more than doubled risk of cardiovascular death (RR=2.10). Interestingly, no statistically significant association was found for the composite outcome combining ACS and stroke, possibly due to heterogeneity in study designs and exposure measurements.
Age and frequency of cannabis use also influenced cardiovascular outcomes. In several studies, younger users (especially aged 18–34) were disproportionately affected by ischemic stroke and myocardial infarction. One Australian cohort found that stroke/transient ischemic attack risk was significantly elevated only in participants using cannabis at least weekly. Similarly, frequent cannabis use (more than once a week) was linked to higher odds of acute MI compared to occasional or non-users. A UK Biobank analysis also revealed a sex-specific risk, with women experiencing a significantly higher increase in cardiovascular mortality from heavy cannabis use compared to men.
From a biological standpoint, cannabinoids—particularly THC—have complex effects on the cardiovascular system. THC activates CB1 receptors, potentially leading to increased heart rate, oxidative stress, and vasoconstriction. These mechanisms may precipitate ischemic events, especially in individuals with preexisting risk factors. In contrast, CB2 activation, often associated with CBD, may have anti-inflammatory properties. Yet, with many cannabis products increasingly high in THC content, the balance is tilted toward risk.
As Stanton Glantz, PhD, and Lynn Silver, MD, MPH, from the University of California San Francisco write, “Cannabis needs to be incorporated into the framework for prevention of clinical cardiovascular disease. So too must cardiovascular disease prevention be incorporated into the regulation of cannabis markets.”
This study provides a critical evidence base for clinicians, policymakers, and regulatory agencies. As legalization continues to expand, the integration of cardiovascular screening, education, and regulation into cannabis policy frameworks will be essential to safeguard public health.
Sources: British Medical Journal: Heart, MedScape