Association Between Marijuana Use and Clinical Outcomes After Coronary Artery Bypass Grafting

Though marijuana use has been linked to an increase in heart failure admissions, no prior study has explored the association between its use and outcomes after coronary artery bypass grafting (CABG). This study examines the relationship between marijuana use and postoperative outcomes in CABG patients.

We utilized data from the National Inpatient Sample database from 2008 to 2018 for CABG patients ≥18 y old. Patients were divided into two groups based on marijuana use (abuse/dependency versus nonuse). Primary outcomes include in-hospital mortality, favorable discharge, and length of stay (LOS). Secondary outcomes include acute kidney injury (AKI), acute myocardial infarction (AMI), and transient ischemic attack (TIA)/stroke. A multivariable model, adjusted for confounding variables, was utilized for each outcome.

A total of 343,796 patients met inclusion criteria for the study, 590 of which were marijuana users. In both marijuana user and nonuser groups, most patients were male and White with an average age of 56.0 and 66.3 y, respectively. There was a nonsignificant decreased odds of in-hospital mortality among marijuana users (odds ratio [OR] = 0.41, [0.141-1.124]). Marijuana users exhibited significantly decreased odds of home discharge (OR = 1.50, [1.24-1.81]), and increased odds of longer LOS (mean 10.4 d versus 9.8 d; OR = 1.14, [1.09-1.20]), AKI (OR = 1.40, [1.11-1.78]), AMI (OR = 1.56, [1.32-1.84]), and TIA/stroke (OR = 1.64, [1.21-2.22]).

Marijuana use and dependency are associated with increased nonhome discharge, AKI, AMI, TIA/stroke, and longer LOS. Further studies are needed to delineate the pathophysiologic derangements that contribute to these unfavorable post-CABG outcomes.