Assessment of patients post reversal with idarucizumab

Idarucizumab, a fully humanized Fab antibody fragment, is indicated for reversal of dabigatran's anticoagulant activity. Idarucizumab neutralizes the anticoagulant effects of dabigatran by binding to dabigatran and its metabolite. In the full analysis of 503 patients, idarucizumab fully reversed the anticoagulant effect of dabigatran in more than 98% of patients. Real-world clinical experience with idarucizumab for dabigatran reversal remains limited. We report 11 real-world clinical cases in which idarucizumab was administered for dabigatran reversal in the setting of bleed (bleeding cohort n = 5) or emergent procedure (emergent procedure cohort, n = 6). Coagulation tests and clinical outcomes were assessed before and after idarucizumab administration. Clinical outcomes included thromboembolic events and hemostasis. The median (IQR) aPTT (seconds) before versus after idarucizumab was 40.4 (36.1) versus 27.3 (6.2) (bleeding cohort) and 50.1 (13.4) versus 26.5 (8.1) (emergent procedure cohort). The median (IQR) INR before and after idarucizumab was 2.0 (1.1) versus 1.2 (0.1) (bleeding cohort) and 1.1 (0.5) versus 1.1 (0.3) (emergent procedure cohort). Hemostasis was achieved in 4/5 patients in the bleeding cohort and 5/6 patients in the emergent procedure cohort. Thrombotic events occurred in four patients with a median time (IQR) from idarucizumab administration of 7.4 (4.3-14.7) days. Idarucizumab achieved adequate dabigatran reversal as evident by normalization of aPTT, INR, and achieving hemostasis. However, our data demonstrates a high thrombotic risk associated with dabigatran reversal with idarucizumab than previously reported.