Heart Transplant Outcomes in Patients with Substance Use Disorder History: A Nationwide Cohort Study Using High-Dimensional Propensity Score Matching

History of substance use is assessed in potential heart transplantation evaluations. The evidence base for this highly consequential practice, linking substance use disorders with poor post-transplantation outcomes, presents methodological limitations. We conducted a retrospective cohort study to address these limitations using high dimensional propensity score matching to compare heart transplant outcomes of patients with and without substance use disorders. Key outcomes included mortality, hospitalization, and organ rejection rates, controlling for confounders. A national dataset of electronic health records of >120 million patients in the United-States (2015-2023) was used to identify heart transplantation patients with substance use disorders (n=808) and controls (n=7066), matched for medical comorbidities and demographic variables. Only after adjusting for sociodemographic and comorbidities of heart transplant recipients, the results revealed no significant differences between groups with and without substance use disorders at one year in mortality (Odds Ratio (OR)=0.96 (95% CI: 0.54, 1.69, p=0.88), hospitalization (OR=1.02 (95% CI: 0.83, 1.25, p=0.840)), organ rejection rates (OR=0.96 (95% CI: 0.78, 1.18, p=0.670)), nor at 5 years in mortality (Hazards Ratio (HR) =1.15 (95% CI: 0.82, 1.61, p=0.410) and organ rejection (HR=0.98 (95% CI: 0.84, 1.14, p=0.810). Future studies must consider confounding factors when evaluating transplant criteria and outcomes in patients with substance use disorders.