Risk assessment of myocarditis in patients undergoing chimeric antigen receptor T-cell therapy: A retrospective cohort analysis

Abstract Background: The advent of immunotherapy in oncology has increased the prevalence of immune-related adverse events. Chimeric Antigen Receptor T-cell (CAR-T) therapy has revolutionized the treatment of hematologic malignancies but has raised concerns about immune-related toxicities, including CAR-T-associated myocarditis. However, evidence regarding the association between CAR-T therapy and myocarditis remains debatable. Methods: Using the National Inpatient Sample (NIS) database, we conducted a retrospective cohort study of patients aged ≥18 years who underwent CAR-T therapy between 2018 and 2023. The study population was divided into two groups: (1) patients with hematologic malignancies who received CAR-T therapy without a prior diagnosis of myocarditis, and (2) patients with hematological malignancies with no history of CAR-T therapy or myocarditis. Propensity score matching was applied to balance baseline characteristics between the cohorts.The incidence of newly diagnosed myocarditis post-CAR-T therapy was analyzed and compared between the groups. Results: A total of 981 patients were included in each group after matching. The incidence of newly diagnosed myocarditis during the study period was 1.02% in both cohorts, with 10 patients in each group affected. The difference in myocarditis incidence between the two groups was not statistically significant (p = 0.268). Kaplan-Meier analysis for the time-to-event outcome revealed no significant difference between the CAR-T cohort and the control group (log-rank test, p = 0.268). The hazard ratio for the onset of myocarditis in the CAR-T cohort compared to the control group was 1.7 (95% CI: 0.346–32.319), but this did not reach statistical significance (p = 0.142). Conclusion: No significant difference in the incidence of autoimmune diseases was observed between the CART-treated group and the healthy control group (p > 0.05). The findings suggest that CART therapy does not substantially increase the risk of developing myocarditis. Our results do not support routine baseline or follow-up testing for autoimmune diseases in patients undergoing CART therapy. These findings can inform clinical guidelines, reducing unnecessary investigations and optimizing resource utilization for this patient population. Further studies with larger cohorts may be warranted to confirm these findings.