Abstract P200: The Heart and Cannabis Cohort (THC Cohort): Associations Between Cannabis Use and Cardiovascular Health at Cohort Inception
Authors: Salomeh Keyhani, Beth Cohen, Dawn M Bravata, Marzieh Vali, Katherine Hoggatt, Peter Austin, Carl Grunfeld, Michael Shlipak
Journal: Circulation (2020)

Background: Cannabis use may adversely impact cardiovascular health through the smoking of particulate matter or through the potential adverse hemodynamic effects of Tetrahydrocannabinol (THC). We assembled a prospective cohort of older Veterans with coronary artery disease (CAD) to examine the effects of cannabis use on: medication use, blood pressure control, and cardiovascular events. Methods: We identified all Veterans 65 to 67 years of age in the Veterans Health Administration (VA) with CAD using national VA data. We included Veterans with at least 1 primary care visit in the prior 2 years. We used text processing to identify mentions of cannabis use (e.g., marijuana, cannabis) in the free text of the medical record and preliminarily categorized patients as potential users and non-users. We then randomly selected patients from each group and performed in-depth telephone health interviews to ascertain cannabis use (e.g., frequency, route), and other important health behaviors and measures, including tobacco and alcohol use, physical activity, depression, and post-traumatic stress disorder. We collected baseline information on blood pressure and comorbid conditions from national VA data. Associations of current cannabis use (past 30 days) with receipt of appropriate medications (i.e., statins, antiplatelets, and beta blockers) were evaluated with multivariable logistic regression. Using linear regression, we also examined associations of current marijuana use with systolic blood pressure and body mass index (BMI). Results: We assembled 792 current cannabis users and 2098 current non-users with CAD. At baseline, the cohort’s mean age was 66 years; 98% were male, 75% white and 18% black. Smoking was the predominant form of cannabis use (90%). The cannabis users had higher use of tobacco cigarettes (42% vs 25%), heavy drinking (31% vs 18%) and other drug use (2.8% vs 1.3%) than non-users (p&lt;0.001). In contrast, cannabis users had lower prevalence of diabetes (36% vs 49%) and hyperlipidemia (76% vs 81%) than non-users (p&lt;0.001). After adjusting for baseline sociodemographic, tobacco, alcohol, drug use, and mental health factors, cannabis use was associated with lower odds of receiving statins (OR 0.74, 95% CI 0.62 to 0.89), antiplatelets (OR 0.68, 95% CI 0.56 to 0.83) and beta blockers (OR 0.71, 95% CI 0.59 to 0.85). Current cannabis use was also associated with higher systolic blood pressure (2 mmHg, 95% CI (0.67, 3.465)) and lower BMI (-1.3 kg/m 2 , 95%CI (-1.87, -0.88)) after adjusting for baseline factors. Conclusions: Cannabis use is associated with lower receipt of guideline-recommended cardiovascular medications among Veterans with CAD. Cannabis use is also associated with higher systolic blood pressure, but lower BMI. Future analyses of this prospective cohort will determine whether cannabis use has independent associations with cardiovascular events.