New research presented at the American Heart Association Scientific Sessions November 16–18 in Philadelphia indicates that young people who are frequent marijuana users are nearly three times more likely to have a stroke than nonusers. The research, which will be published in the journal Stroke, also found that people with cannabis-use disorder have a 50 percent greater risk of being hospitalized for heart arrhythmias. “There’s more and more data raising concern for the negative cardiovascular effects of cannabis, whether it’s stroke, arrhythmias or myocardial infarction,” says Christine Tompkins, MD, an acting associate professor of cardiology at the Emory School of Medicine in Atlanta, who was not involved in the research. “We need to really get a better understanding of what the risks are associated with cannabis use, since it’s becoming more widely used,” she adds. To determine the association between marijuana use and stroke, researchers used pooled data from the Behavioral Risk Factor Surveillance System (2016–2017), a nationally representative cross-sectional survey conducted by the Centers for Disease Control and Prevention (CDC), to examine a total of 43,860 young adults (49.9 percent male and 50.1 percent female). Overall, 13.6 percent reported using marijuana within the last month. Among the results, researchers found that young adults with recent marijuana use had nearly two times higher odds of stroke compared with nonusers. For frequent users, defined as those who used marijuana 10 days or more a month, the risk rose to 2.5 times higher than nonusers. In frequent users of pot who also smoked cigarettes or e-cigarettes, stroke risk was nearly three times higher when compared with nonusers. Because the study was observational, researchers tried to control for many factors that could impact stroke risk, such as other health habits, drug use, education and income level, and relevant comorbidities. Preliminary findings of this observational study could be a “wake-up call,” at least for young heavy cannabis users, says a coauthor of the study, Rupak Desai, MBBS, a research fellow in the division of cardiology at the Atlanta VA Medical Center. “In addition to this analysis of survey-based data, our previous analysis from hospitalizations across the United States also showed an alarming rising trend in acute cardiovascular events among young cannabis users,” says Dr. Desai, referencing other research he coauthored that was published in the journal Medicina in August 2019. Although this study is observational and doesn’t prove cause and effect, these results indicate that physicians should ask patients about marijuana use during clinical visits, says Dr. Tompkins. “If they identify patients who are users, they should educate them about the potential of increased risk [of cardiovascular events],” she says.
Increased Hospitalizations Due to Heart Arrhythmias Associated With Marijuana Use Disorder
In a second study, researchers examined 570,556 arrhythmia inpatients ages 15 to 54 from the Agency for Healthcare Research and Quality’s Nationwide Inpatient Sample. They found that people who were admitted for cardiac arrhythmia with a diagnosis of cannabis use disorder (frequent, compulsive use of marijuana) had a 50 percent greater risk of being hospitalized for an arrhythmia compared with nonusers. Young African American men (ages 15–24) with cannabis use disorder (CUD) had the greatest risk of being hospitalized for arrhythmia, although CUD was more common among white men between ages 45 and 54. According to the authors, while some arrhythmias are benign, others can be life-threatening. “The effects of using cannabis are seen within 15 minutes and last for around three hours. At lower doses, it is linked to a rapid heartbeat. At higher doses, it is linked to a too-slow heartbeat,” says a coauthor of the study, Rikinkumar S. Patel, MD, MPH, a resident physician in the department of psychiatry at the Griffin Memorial Hospital in Norman, Oklahoma.
Researchers Agree More Studies Are Needed
This new research is important, but they are both observational studies, points out Tompkins. “As both studies contain large numbers and very diverse populations, there can be a lot of comorbidities and other health factors going on. We really need more randomized prospective studies to get at what are the true effects of cannabis in heart health,” she says. Desai agrees. “Until future prospective studies are available with more granular data and endpoints, this study should be considered a crucial first step towards identifying young cannabis users remaining at high risk for cardiovascular events,” he says. Part of the problem is a hesitancy from both consumers of cannabis and the scientific community to look at both sides of the data, says Tompkins. “There is really a paucity of evidence available around what are the mechanisms going on behind these clinical findings. The scientific community needs to give more attention to cannabis use for us get to the bottom of this,” Tompkins says.
