Article Impact Level: HIGH Data Quality: STRONG Summary of JACC: Advances, 101698. https://doi.org/10.1016/j.jacadv.2025.101698 Dr. Ibrahim Kamel et al.
Points
- A large retrospective study found that cannabis users under 50 had a 6-fold higher risk of heart attack, along with increased risks for ischemic stroke (4-fold), heart failure (2-fold), and cardiovascular death (3-fold) compared to non-users.
- A meta-analysis of 12 studies with over 75 million individuals found a 50% increased risk of heart attack among cannabis users, with 7 out of 12 studies showing a significant link between cannabis use and heart attacks.
- The meta-analysis lacked data on cannabis dosage, duration of use, and concurrent substance use (e.g., tobacco, cocaine), which may affect cardiovascular outcomes.
- Researchers suggest that cannabis may contribute to cardiovascular risk by altering heart rhythm, increasing heart muscle oxygen demand, and impairing blood vessel function (endothelial dysfunction).
- While findings suggest caution in cannabis use, especially for those with underlying cardiovascular risks, more prospective studies are needed to clarify mechanisms and identify high-risk populations.
Summary
Two recent studies have added substantial evidence linking cannabis use with an increased risk of cardiovascular events, particularly heart attacks. In a large retrospective study, researchers found that individuals under the age of 50 who used cannabis had a more than sixfold increased risk of heart attack compared to non-users. This study, based on data from over 4.6 million people, also indicated higher risks for ischemic stroke (4-fold), heart failure (2-fold), and cardiovascular death (3-fold) among cannabis users, with a follow-up period of over three years. All participants were free of significant cardiovascular comorbidities at baseline, with normal blood pressure, LDL cholesterol levels, and no history of diabetes, smoking, or coronary artery disease.
The second study, a meta-analysis of 12 previously published studies, pooled data from more than 75 million individuals and found a 50% increased risk of heart attack among cannabis users. Of the 12 studies included, seven demonstrated a significant positive association between cannabis use and heart attacks, with cannabis users being 1.5 times more likely to suffer from a heart attack compared to non-users. However, the analysis was limited by variations in the data, such as the inability to account for factors like the duration and amount of cannabis use or concurrent use of other substances like tobacco and cocaine.
The researchers hypothesize that cannabis may impact the cardiovascular system by altering heart rhythm, increasing oxygen demand in the heart muscle, and causing endothelial dysfunction, which impairs blood vessel relaxation and blood flow. While the exact mechanisms remain unclear, the studies highlight the need for caution regarding cannabis use, especially for individuals with underlying cardiovascular risk factors. Further prospective studies are necessary to better understand these risks and to identify specific groups that may be more susceptible to the cardiovascular effects of cannabis use.
Link to the article: https://www.sciencedirect.com/science/article/pii/S2772963X25001152
References Kamel, I., Mahmoud, A. K., Twayana, A. R., Younes, A. M., Horn, B., & Dietzius, H. (2025). Myocardial infarction and cardiovascular risks associated with cannabis use: A multicenter retrospective study. JACC: Advances, 101698. https://doi.org/10.1016/j.jacadv.2025.101698
