A new multicenter retrospective study found that the risk of myocardial infarction and other major adverse cardiovascular events may be higher among cannabis users compared with nonusers, even in individuals without traditional cardiovascular risk factors.
In the study, published as a preproof in JACC: Advances, investigators analyzed data from 4.6 million adults aged 50 years and younger in the TriNetX health research network, identifying 93,267 cannabis users and 4.5 million nonusers. They excluded individuals with significant baseline comorbidities, including hypertension, hyperlipidemia, coronary artery disease, diabetes mellitus, and tobacco use in order to isolate the cardiovascular effects of cannabis.
After propensity score matching, each group had 89,776 patients with balanced demographics and baseline health conditions. Cannabis users had a 6.185-fold increased risk of myocardial infarction (MI) (odds ratio [OR] = 6.214, 95% confidence interval [CI] = 4.913–7.86) compared with nonusers. The absolute risk for MI was 0.558% in cannabis users vs 0.09% in nonusers.
Previous research suggested that the risk of MI may be nearly fivefold higher within 1 hour of cannabis consumption, highlighting the potential acute effects of cannabis use on cardiac health.
Cannabis use was also associated with increased risks for ischemic stroke, major adverse cardiovascular events, heart failure, and all-cause mortality. Kaplan-Meier survival analysis showed lower survival probabilities among cannabis users, with hazard ratios ranging from 1.81 for all-cause mortality to 7.57 for MI.
Cannabis users had higher rates of depressive disorders and obesity. The mean follow-up duration was 35.7 ± 23.4 months among cannabis users and 44.2 ± 23.8 months among nonusers.
The investigators suggested that cardiovascular risks may be linked to endothelial dysfunction, proinflammatory cytokine release, and oxidative stress, all of which contribute to coronary microvascular dysfunction and plaque destabilization. Study limitations included a lack of detailed cannabis consumption data and potential misclassification.
"[T]he inherent limitations of real-world data often result from inconsistent patient reporting in electronic medical records," the study authors emphasized.
The findings indicated that cannabis use may be an independent cardiovascular risk factor, even in young adults without traditional risk factors. Clinicians were encouraged to consider these findings in patient discussions, particularly as cannabis use increases worldwide, with over 192 million users reported by the United Nations in 2018.
The authors reported no conflicts of interest.