In the first part, in an observational study, daily cannabis use was associated with 34% higher odds for CAD, compared with never-users, in a large population-based U.S. cohort. Less frequent use was not associated with increased odds for CAD.
In the second part, people with a genetic susceptibility to cannabis use disorder or severe cannabis dependency had an increased risk for CAD, compared with other people.
Ishan Paranjpe, MD, the study’s lead author, reported these results in a press briefing and will present the study at the upcoming joint scientific sessions of the American College of Cardiology and the World Heart Federation 2023.
“A couple of takeaway points are that daily cannabis use, but not less frequent cannabis use, was associated with CAD” in the large population-based cohort, said Dr. Paranjpe, a resident physician at Stanford (Calif.) University, during the press conference.
“This analysis was adjusted for several possible confounders including age, sex at birth, [body mass index (BMI)], race, education, cigarette use, hypertension, high cholesterol, and diabetes,” he noted, and even after accounting for these risk factors, the association with heart disease remained.
“And the next thing, using Mendelian randomization, we sort of implied that there might be a causal relationship between cannabis and heart disease. Importantly this effect is independent of alcohol and cigarette use.
“The notion that cannabis is completely benign is probably wrong, and there might be certain risk of certain cardiovascular effects of cannabis we should be more on the lookout for,” Dr. Paranjpe said in an interview.
“Our main conclusion was that prevalent CAD is associated with cannabis consumption,” he added. “Other mechanistic work published in Cell has also shown that cannabis causes vascular inflammation that may lead to CAD.
“Thus, there is growing evidence from both laboratory and population studies that cannabis consumption may be harmful for cardiovascular health,” he said. “However, we still need more work on whether it affects the risk of incident cardiovascular events (i.e., stroke, heart attack) in patient[s] with existing CAD.”
ASCVD risk
Invited to comment, Robert L. Page II, PharmD, chair of the writing group for the American Heart Association’s scientific statement Medical Marijuana, Recreational Cannabis, and Cardiovascular Health, published in 2020, said, “This adds to our hypothesis that if you are using marijuana over a longer period, greater exposure, you’re going to see an increase in the risk” for atherosclerotic cardiovascular disease (ASCVD).
“We’re seeing this increased risk for ASCVD in young adults between ages 18 to 40 – people who think that they’re invincible,” Dr. Page, a professor at the University of Colorado at Denver, Aurora, who was not involved with this research, told this news organization in an interview.
“The bottom line is that the risk that they are seeing is what has also been documented in other observational studies, and it adds fuel to the fire. We need to be paying close attention to this,” he said.
“Primary care [clinicians], cardiologists, need to address this, particularly in younger adults – because that’s where you’re seeing the highest amount of use.”