Cannabis use and Post-Transplant Outcomes in Heart Transplant Recipients: A Propensity-Matched Cohort Study

Cannabis use is increasingly prevalent in the United States, yet its impact on outcomes after heart transplantation remains uncertain. This retrospective cohort study using the TriNetX network, included adult heart transplant recipients between 2005 and 2025. Patients with documented cannabis-related disorders prior to transplantation were compared with non-users using 1:1 propensity score matching. Five-year outcomes included all-cause mortality, transplant-related complications-rejection/failure/infection, acute kidney injury (AKI), and calcineurin inhibitor-associated cardiometabolic adverse effects. After matching, 1054 patients were included in each cohort. All-cause mortality at five years was similar between cannabis users and non-users (17.9% vs. 17.8%; HR 0.99, 95% CI 0.82-1.22; p = 0.99). At five years, cannabis use was associated with higher rates of transplant-related complications (HR 1.49, 95% CI 1.31-1.70, p<0.001), including rejection (HR 1.50, p<0.001) and graft failure (HR 1.62, p<0.001). Rates of transplant infection and AKI were similar between groups. New-onset cardiometabolic adverse effects were more frequent among cannabis users (HR 1.53, p = 0.004). In a re-run analysis including cardiac allograft vasculopathy (CAV) as an additional outcome, CAV was substantially more frequent among cannabis users (HR 2.81, 95% CI 2.14-3.68; p<0.001). This study highlights an important signal that requires prospective investigation and may inform future transplant evaluation and policy.