Association of smoking cannabis with cardiovascular events among Veterans with coronary artery disease

Published in the Circulation. Here is a link to the article.

Regenstrief Institute authors: Dawn Bravata, M.D.

A new study brings reassuring news for older adults using cannabis: smoking or consuming cannabis does not appear to raise the risk of heart attacks, strokes or cardiovascular death—at least among older veterans with pre-existing heart disease.

Researchers examined 4,285 U.S. veterans, aged 66 to 68, who were born between 1950 and 1952 and had been diagnosed with coronary artery disease. Participants were enrolled in the THC (Heart and Cannabis) Cohort between April 2018 and March 2020. They were interviewed about their cannabis use in the prior 30 days, including whether they smoked, vaped or consumed edibles.

The study tracked each participant for an average of 3.3 years, analyzing the risk of major cardiovascular events, including fatal and nonfatal heart attacks, strokes and cardiovascular-related deaths.

Among the group, 1,015 veterans reported recent cannabis smoking, while 3,122 reported no recent use. In total, 563 cardiovascular events occurred during the follow-up. However, researchers found no significant link between cannabis use and increased cardiovascular risk. Smoking cannabis was associated with a slightly lower but not statistically significant hazard ratio (0.87; 95% CI, 0.61–1.24), and no form of cannabis use—smoking, vaping or edibles—showed a heightened risk.

The findings suggest that, at least in this older population with heart disease, cannabis use may not independently elevate the risk of serious cardiovascular events. Researchers caution, however, that further studies are needed to evaluate long-term effects and outcomes in broader populations.

Authors: 

Salomeh Keyhani^1,2, Beth E Cohen^1,2, Marzieh Vali³, Katherine J Hoggatt^1,2, Dawn M Bravata^4,5, Peter C Austin⁶, Emily Lum³, Deborah Hasin⁷, Carl Grunfeld^1,2, Michael G Shlipak^1,2,8

Affiliations: 

¹Center for Data to Discovery and Delivery Innovation, San Francisco Veterans Administration, CA (S.K., B.E.C., K.J.H., C.G., M.G.S.).

²Department of Medicine, University of California, San Francisco. (S.K., B.E.C., K.J.H., C.G., M.G.S.).

³Northern California Institute for Research and Education, San Francisco (M.V., E.L.).

⁴Center for Health Information and Communication, Richard L. Roudebush VA Medical Center, Indianapolis, IN (D.M.B.).

⁵Department of Medicine, Indiana University School of Medicine, Indianapolis (D.M.B.).

⁶University of Toronto, Canada (P.C.A.).

⁷Department of Psychiatry, Vagelos School of Medicine, Columbia University, New York, NY (D.H.).

⁸Department of Epidemiology and Biostatistics, University of California, San Francisco. (M.G.S.).