Cannabis smoking was not independently associated with the risk of a cardiovascular event (acute myocardial infarction [AMI], stroke or cardiovascular death) among veterans with coronary artery disease (CAD), according to the THC Cohort (Heart and Cannabis) study published July 21 in Circulation.

Salomeh Keyhani, MD, et al., analyzed data from 4,285 veterans (mean age, 68 years; 2% women), of whom 1,015 adults self-reported smoking cannabis in the previous 30 days. Overall, participants who used cannabis had fewer comorbid conditions (including hypertension, hyperlipidemia, previous AMI, heart failure, atrial fibrillation) than nonusers. In contrast, cannabis users had a lower socioeconomic status and were more likely to engage in adverse health behaviors vs. nonusers.

Results showed that during a mean 3.3-year follow-up, 563 participants experienced a cardiovascular event. Specifically, smoking cannabis was not associated with the composite outcome of AMI, stroke and cardiovascular death (hazard ratio [HR], 0.87) vs. not smoking cannabis in the previous 30 days. Likewise, recent use of any form of cannabis (smoking, vaping, edibles) was not associated with cardiovascular events (HR, 0.85).

Similar findings revealed no significant association between cardiovascular events and daily or nondaily cannabis smoking (HR, 0.93 and 0.72). Moreover, no association was found between cardiovascular events and current and former cannabis smoking (HR, 0.98 and 1.30) or for all-cause mortality among those smoking vs. not smoking cannabis in the last 30 days (HR, 0.96).

The authors write that to their knowledge this is first well-powered study to evaluate the associations of self-reported cannabis use and long-term cardiovascular risk. They note the lack of an association in this study may be due in part to the numerous competing risk factors and suggest that cannabis use may be a less important risk factor in the setting of prevalent disease. Similar studies are suggested of adults in the general population as well as "those with lifetime tobacco nonuse … to further examine the association of cannabis use with cardiovascular events."