Disclosures: Vaduganathan and DeFilippis reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
January 20, 2020
3 min read

More than 2 million patients with CVD have reported marijuana use

Disclosures: Vaduganathan and DeFilippis reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
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Muthiah Vaduganathan

Despite the modest strength of current evidence, cardiologists should screen and test their patients for marijuana use in select CV settings, according to a review published in the Journal of the American College of Cardiology.

“Patients are increasingly inquiring about the relative safety of marijuana use,” Muthiah Vaduganathan, MD, MPH, cardiologist at Brigham and Women’s Hospital Heart and Vascular Center, told Healio. “As a cardiovascular community, we need to be equipped with evidence-based responses.”

Available data on usage rates

According to the 2015 National Survey on Drug Use and Health, marijuana was the most commonly used drug of abuse. In addition, it is estimated that 2 million of the 89.6 million adults who reported marijuana use in the National Health and Nutrition Examination Survey from 2015 to 2016 have CVD, Ersilia M. DeFilippis, MD, second-year fellow in the division of cardiology at Columbia University Irving Medical Center, and colleagues wrote.

“While tobacco smoking in the U.S. has been declining, marijuana use is accelerating, and for the first time, there are more persons estimated to be using marijuana than smoking cigarettes,” Vaduganathan said in an interview. “Until further data are available, we advise caution regarding the use of marijuana in our highest-risk patients with established cardiovascular disease.”

As marijuana use and potency increases, adverse health effects related to cannabis have been reported in case series, case reports and observational studies. Several CV risks associated with marijuana include smoking-related cardiotoxicity, CAD, arrhythmias, cerebrovascular disease, cardiomyopathy and peripheral artery disease. Metabolic alterations may also occur with marijuana use such as weight gain in patients with HIV.

“Converging lines of evidence suggest potential cardiovascular toxicity of marijuana use,” Vaduganathan said in an interview. “Cannabinoid receptors are expressed broadly including on heart cells, platelets and fat cells. Marijuana use may potentiate physiological responses (such as increases in heart rate and blood pressure) that may be harmful to patients with cardiovascular disease. The combustion products of marijuana smoking may be similar to those of tobacco smoking. Observational studies have identified potential associations between the use of marijuana and subsequent cardiovascular events.”

Marijuana use may interfere with multiple CV therapy classes by inhibiting the cytochrome P450 family. Medications affected with use include calcium channel blockers, antiarrhythmics, beta-blockers, statins and warfarin.

Approaching discussions with patients

Clinical care should incorporate screening, counseling and testing when appropriate, given what is known about prevalent marijuana use, especially in patients with established CVD, according to the review. Cardiologists should ask their patients questions about quantity, frequency and methods of administration, and urine toxicology may be reasonable in patients with MI and new-onset HF.


“These will be highly individualized and nuanced discussions,” Vaduganathan told Healio. “There are a variety of tools available for assessing marijuana use.”

A multidisciplinary assessment with a pharmacist is encouraged for patients with CVD and known marijuana use to determine whether doses of therapies should be changed due to drug interactions, according to the review.

“Heightened awareness is needed among cardiovascular specialists of the broad range of potential health consequences of marijuana and its derivatives,” DeFilippis and colleagues wrote. “Cardiovascular specialists should have open discussions with patients acknowledging the limited scientific data but potential cardiovascular hazards of marijuana use, especially when used via smoking/inhalation routes.”

Since guidelines and regulations are limited for marijuana use and CVD, more research is needed to potentially formulate them, according to the review. Significant barriers exist regarding researching cannabis use such as variability in state laws and implementation and heterogeneity of the drug.

“Further research needed in this area include high-quality epidemiological surveillance of the update of marijuana among high-risk patient populations,” Vaduganathan said in an interview. “We also need in-depth pharmacological studies on the duration and intensity of interactions between marijuana and commonly administered medications. Lastly, we need qualitative studies regarding patient perceptions on use and perceived safety of marijuana.” – by Darlene Dobkowski

For more information:

Muthiah Vaduganathan, MD, MPH, can be reached at Brigham and Women’s Hospital Heart & Vascular Center, Harvard Medical School, 75 Francis St., Boston, MA 02115; email: mvaduganathan@bwh.harvard.edu; Twitter: @mvaduganathan.

Disclosures: Vaduganathan and DeFilippis reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.