Nav: Home

An estimated 2 million people with heart disease have used marijuana, finds study

January 20, 2020

Marijuana use is on the rise as more states legalize it for medicinal and recreational purposes, and physicians are fielding more questions about its safety.

Although smoking tobacco is responsible for approximately one in four deaths from cardiovascular disease, the effects of smoking marijuana on the heart are not fully understood. Some studies suggest that marijuana can trigger heart attacks and strokes in some users.

Ersilia DeFilippis, MD, a second-year cardiology fellow at Columbia University Irving Medical Center and NewYork-Presbyterian, first became interested in marijuana's effect on the heart a few years ago when studying heart attacks in people under 50. "We noted that 10% of patients in a registry of young heart attack patients had used marijuana and/or cocaine," she says.

DeFilippis and colleagues recently reviewed the medical literature to find out what's known about marijuana's effect on the heart and what's still unknown. Their full report was published Jan. 20 in the Journal of the American College of Cardiology.

Here are five highlights from the review:

2 Million People with Heart Disease Have Used Marijuana

Marijuana is the most commonly used drug of abuse. It's estimated that approximately 90 million American adults have used the drug at least once in their life, and more than 39 million have used the drug in the past year.

Based on responses to the National Health and Nutrition Examination Survey from 2016, DeFilippis and her colleagues estimate that about 2 million adults in the United States who have cardiovascular disease currently use marijuana or have used the drug in the past.

"In addition to the 2 million marijuana users with diagnosed cardiovascular disease, many more may be at risk," DeFilippis says. "With many adolescents and young adults turning to marijuana, it is important to understand the cardiovascular implications they may face years down the line."

Cannabinoids Can Interact with Drugs Used to Treat Heart Disease

Cannabinoids inhibit certain enzymes in the body, which affects 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 these prescribed drugs in the body, though limited data are available to guide physicians in adjusting dose to compensate for marijuana use.

Marijuana's Potency Today Is Higher

The potency of marijuana--the percentage of THC contained in the plant--has steadily increased over the past 30 years, from about 4% in the mid-1990s to 12% in 2014. However, most scientific studies of cannabis tested products with THC levels between 1.5% and 4%.

"Higher potency may translate into greater effects on the conduction system, the vasculature, and the muscle of the heart," DeFilippis says. "It also highlights the need for real-world data given the variety of marijuana products and formulations available for purchase."

THC is the most psychoactive chemical in marijuana, but marijuana also contains more than 100 compounds, called cannabinoids, that are chemically related to THC.

Receptors for cannabinoids are highly concentrated in the nervous system but also can be found in blood cells, muscle cells, and other tissues and organs.

Marijuana May Be Linked to Heart Attacks and Strokes

Studies have identified marijuana smoking as a potential trigger of heart attacks, and marijuana use is not infrequently detected in adults who have experienced heart attacks at an early age (under 50).

A small experimental study found that smoking marijuana can bring on angina (chest pain) more quickly in patients with coronary heart disease compared with smoking a placebo.

Though current evidence for a link between marijuana and heart attacks is modest, it's thought that smoking marijuana may increase cellular stress and inflammation, which are known to be precipitating factors for coronary artery disease and heart attacks.

Cerebrovascular events, including strokes, also have been associated with marijuana use. It's thought that marijuana may induce changes in the inner lining of blood vessels or alter blood flow.

Physicians Should Screen for Marijuana Use

"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 says.

"Therefore, asking patients about marijuana use may help in risk assessment. In addition, we know that marijuana use affects the metabolism of many common cardiac drugs. In order to make sure patients are getting therapeutic doses without untoward side effects, it is important for cardiologists to talk to their patients about marijuana use."
-end-
About the Paper

The paper is titled, "Marijuana Use in Patients With Cardiovascular Disease," and was published Jan. 20 in the Journal of the American College of Cardiology.

The other authors are: Navkaranbir S. Bajaj (University of Alabama at Birmingham, Birmingham, Alabama), Amitoj Singh (University of Arizona), and Rhynn Malloy, Michael M. Givertz, Ron Blankstein, Deepak L. Bhatt, and Muthiah Vaduganathan ((Brigham and Women's Hospital and Harvard Medical School).

Ersilia DeFilippis reports no relationships relevant to the contents of this paper to disclose. (See paper for information on other authors).

Columbia University Irving Medical Center provides international leadership in basic, preclinical, and clinical research; medical and health sciences education; and patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the Vagelos College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Columbia University Irving Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest faculty medical practices in the Northeast. For more information, visit cuimc.columbia.edu or columbiadoctors.org.

Columbia University Irving Medical Center

Related Heart Disease Articles:

New 'atlas' of human heart cells first step toward precision treatments for heart disease
Scientists have for the first time documented all of the different cell types and genes expressed in the healthy human heart, in research published in the journal Nature.
With a heavy heart: How men and women develop heart disease differently
A new study by researchers from McGill University has uncovered that minerals causing aortic heart valve blockage in men and women are different, a discovery that could change how heart disease is diagnosed and treated.
Heart-healthy diets are naturally low in dietary cholesterol and can help to reduce the risk of heart disease and stroke
Eating a heart-healthy dietary pattern rich in vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, vegetable oils and nuts, which is also limits salt, red and processed meats, refined-carbohydrates and added sugars, is relatively low in dietary cholesterol and supports healthy levels of artery-clogging LDL cholesterol.
Pacemakers can improve heart function in patients with chemotherapy-induced heart disease
Research has shown that treating chemotherapy-induced cardiomyopathy with commercially available cardiac resynchronization therapy (CRT) delivered through a surgically implanted defibrillator or pacemaker can significantly improve patient outcomes.
Arsenic in drinking water may change heart structure raising risk of heart disease
Drinking water that is contaminated with arsenic may lead to thickening of the heart's main pumping chamber in young adults, according to a new study by researchers at Columbia University Mailman School of Public Health.
New health calculator can help predict heart disease risk, estimate heart age
A new online health calculator can help people determine their risk of heart disease, as well as their heart age, accounting for sociodemographic factors such as ethnicity, sense of belonging and education, as well as health status and lifestyle behaviors.
Wide variation in rate of death between VA hospitals for patients with heart disease, heart failure
Death rates for veterans with ischemic heart disease and chronic heart failure varied widely across the Veterans Affairs (VA) health care system from 2010 to 2014, which could suggest differences in the quality of cardiovascular health care provided by VA medical centers.
Heart failure: The Alzheimer's disease of the heart?
Similar to how protein clumps build up in the brain in people with some neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, protein clumps appear to accumulate in the diseased hearts of mice and people with heart failure, according to a team led by Johns Hopkins University researchers.
Women once considered low risk for heart disease show evidence of previous heart attack scars
Women who complain about chest pain often are reassured by their doctors that there is no reason to worry because their angiograms show that the women don't have blockages in the major heart arteries, a primary cause of heart attacks in men.
Where you live could determine risk of heart attack, stroke or dying of heart disease
People living in parts of Ontario with better access to preventive health care had lower rates of cardiac events compared to residents of regions with less access, found a new study published in CMAJ (Canadian Medical Association Journal).
More Heart Disease News and Heart Disease Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.