Study: 2 Million People with Heart Disease Estimated to Have Used Marijuana

A recent study estimates that approximately 2 million adults in the United States who have cardiovascular disease currently use marijuana or have used the drug in the past. This estimate is based on responses from the National Health and Nutrition Examination Survey from 2016.

The percentage of THC contained in the marijuana plant, also known as the potency, has increased over the past 30 years, from approximately 4% in the mid-1990s to 12% in 2014, according to researchers from Columbia University Irving Medical Center. However, many scientific studies of cannabis tested products with THC levels between 1.5% and 4%. Receptors for cannabinoids are highly concentrated in the nervous system, but can be found in blood cells, muscle cells, and other tissues and organs.

In addition to its effects on the nervous system, cannabinoids can affect the metabolism of many drugs for heart disease, including antiarrhythmics, statins, calcium-channel blockers, beta blockers, and warfarin. Researchers believe that cannabinoids may increase the activity of prescription drugs in the body, although limited data are available to help physicians adjust the dose of the prescriptions to compensate for marijuana use.

Ersilia DeFilippis, MD, and her colleagues evaluated past studies that identified marijuana smoking as a potential trigger of heart attacks. One small experimental study showed that smoking marijuana can bring on chest pain quicker in patients with coronary heart disease compared with smoking a placebo.

Many prior studies have connected marijuana smoking with an increase in cellular stress and inflammation, which are known to be precipitating factors for coronary artery disease and heart attacks, according to the authors of the current study. Cerebrovascular events, including strokes, are also thought to be associated with marijuana use, inducing changes in the inner lining of blood vessels or altering blood flow.

“Although we need more data, the evidence we do have indicates that marijuana use has been associated with coronary artery disease, arrhythmia, cardiomyopathy, and more,” DeFilippis said in a prepared statement. “Therefore, asking patients about marijuana use may help in risk assessment.”

DeFilippis also suggests that cardiologists talk to their patients about marijuana use to make sure patients are getting therapeutic doses of their cardiac drugs without untoward side effects.

REFERENCE

Study estimates 2 million people with heart disease have used marijuana. Columbia University Irving Medical Center. https://www.cuimc.columbia.edu/news/study-estimates-2-million-people-heart-disease-have-used-marijuana. Published January 20, 2020. Accessed January 27, 2020.