Genetic analysis links cannabis use disorder to higher risk of atrial fibrillation, heart failure, and stroke | Research

The takeaway

A Mendelian randomization study found genetic liability to cannabis use disorder was associated with increased risk of atrial fibrillation, heart failure, pulmonary embolism, and stroke, even after adjusting for smoking, BMI, and other risk factors.

Cardiologists, cannabis users with cardiovascular concerns, and researchers studying cannabis-heart relationships.

Independent genetic link to atrial fibrillation, heart failure, PE, and stroke

What the researchers found

Genetic liability to cannabis use disorder was associated with higher risk of atrial fibrillation, heart failure, pulmonary embolism, and stroke in both univariable and multivariable MR analyses adjusting for smoking, alcohol, BMI, lipids, diabetes, hypertension, and depression. Initial associations with coronary artery disease, myocardial infarction, and deep venous thrombosis did not persist after adjustment, suggesting mediation by traditional cardiovascular risk factors.

Why it matters

Mendelian randomization reduces confounding compared to observational studies. Finding that cannabis use disorder has cardiovascular risks independent of traditional risk factors strengthens the case for a causal relationship.

The numbers in context

12 SNPs used as instruments. Significant associations persisted for atrial fibrillation, heart failure, pulmonary embolism, and stroke after multivariable adjustment. Associations with coronary artery disease, MI, and DVT were mediated by smoking, BMI, LDL, hypertension, and depression.

How the study worked

Two-sample Mendelian randomization using 12 SNPs from the largest GWAS of cannabis use disorder as instrumental variables. Cardiovascular outcomes from published GWAS. Inverse-variance weighted method with sensitivity analyses. Multivariable MR adjusted for potential mediators.

What this study cannot tell us

MR instruments for cannabis use disorder may capture pleiotropic effects. Cannot distinguish cannabis use disorder from occasional use. European ancestry samples limit generalizability. Some sensitivity analyses were inconsistent.

How to read the evidence

Mendelian randomization provides stronger causal evidence than observational studies, though some sensitivity analyses were inconsistent.

When this study was published

Published in 2022.

The bigger picture

While many cardiovascular risks of cannabis may be driven by co-occurring factors like smoking and obesity, the independent associations with atrial fibrillation and stroke suggest direct cardiovascular effects that warrant further investigation.

Questions still open

What biological mechanisms link cannabis specifically to atrial fibrillation and stroke? Does the cardiovascular risk differ by method of consumption? Would recreational cannabis users without disorder-level use face the same risks?

Common questions

Does cannabis use cause heart problems?

This genetic analysis found that liability to cannabis use disorder was associated with increased risk of atrial fibrillation, heart failure, pulmonary embolism, and stroke, even after accounting for smoking, obesity, and other risk factors, suggesting a direct cardiovascular effect.

Were all cardiovascular risks independent of other factors?

No. Initial links to coronary artery disease, heart attack, and deep vein thrombosis were explained by co-occurring factors like smoking and obesity. But atrial fibrillation, heart failure, PE, and stroke associations persisted after adjustment.

Read the original research

Association of cannabis use disorder with cardiovascular diseases: A two-sample Mendelian randomization study.

Frontiers in cardiovascular medicine, 9, 966707

View on PubMed ↗Publisher’s paper ↗

Citation

Chen, Miao; Lu, Yun-Long; Chen, Xiao-Fan; Wang, Zhen; Ma, Liang. (2022). Association of cannabis use disorder with cardiovascular diseases: A two-sample Mendelian randomization study.. Frontiers in cardiovascular medicine, 9, 966707. https://doi.org/10.3389/fcvm.2022.966707