Abstract 4137535: Gastrointestinal Bleeding Risk: Diltiazem versus Metoprolol in Patients on Rivaroxaban, Apixaban, or Dabigatran.

Introduction: A recent JAMA study by Ray et al., reported severe bleeding risk among older adults with atrial fibrillation (Afib) receiving apixaban or rivaroxaban along with diltiazem compared to metoprolol. Our investigation extended to evaluating the gastrointestinal (GI) bleeding risk associated with various Xa inhibitors and dabigatran when combined with either diltiazem, or metoprolol among all adults ages 18 and older. Method: We conducted a comparative retrospective cohort study using de-identified patient data obtained from the global network of the TriNetX platform, a comprehensive electronic health records system comprising 120 healthcare systems and more than 147 million patients worldwide. The cohorts were divided into patients treated with diltiazem vs. metoprolol while receiving apixaban or rivaroxaban (Cohort A), patients receiving metoprolol with apixaban vs. rivaroxaban treatment (Cohort B), patients treated with diltiazem with apixaban vs rivaroxaban (Cohort C), and patients treated with diltiazem vs metoprolol who received dabigatran (Cohort D). The risk of gastrointestinal hemorrhage among the cohorts was evaluated. Propensity score matching was employed to balance baseline characteristics between the cohorts, including age, sex, ethnicity, and comorbidities. Results: The risk of GI bleed in patients taking diltiazem with either apixaban or rivaroxaban was 6.3%, while the risk in patients taking metoprolol with either of these Xa inhibitors was 5.7 % (p< 0.0001, 95%CI (1.074,1.111), RR 1.09. In patients taking metoprolol with apixaban, GI bleed risk was 5.4%, compared to 6.4% in those taking metoprolol with rivaroxaban (p< 0.0001, 95% CI (0.838, 0.868), RR 0.85. For patients taking diltiazem with rivaroxaban, GI bleed risk was 7.3%, whereas it was 5.8% in those taking diltiazem with apixaban (p< 0.0001, 95% CI (1.194, 1.265), RR 1.23. Risk of GI bleed in patients taking diltiazem with dabigatran was 7.4%% while it was 6.71% for patients treated with metoprolol and dabigatran (p< 0.0011, CI 95% (1.038,1.16), RR 1.097) Discussion: Global patients’ data in this study suggested similar findings reported by Ray et al. Additionally, among all ages adults with Afib, treatment with metoprolol and apixaban was associated with the lower risk of GI bleed when compared with metoprolol and rivaroxaban. While the highest risk of GI bleed was associated with concurrent diltiazem and dabigatran use.