Idarucizumab for Reversal of Dabigatran: Multicenter Real-World Experience
Authors: Barzallo Burbano Paola Alejandra , Meijón Mar , Revilla Calvo Nuria , Blanco Bañares María Jesús , Fernández Begoña , Rodríguez-González Ramón , Sola Aparicio María Elena , Rosado Sierra Belén , Asenjo Correa Susana , Gutiérrez Isabel , Llamas Sillero María Pilar , Díez-Martín José L. , Pérez-Rus Gloria , Pascual Izquierdo Cristina 
Published: November 2021

Abstract
Introduction: Idarucizumab is a humanized monoclonal antibody fragment that binds to dabigatran and reverses its anticoagulant activity. It has been available in Spain since June 2016 and is indicated for imminent surgery or invasive procedures and life-threatening bleeding. The aim of the study was to describe the actual experience with idarucizumab in different centers in Madrid.
Methods: Patients with electronic prescription of idarucizumab between June 2016 and July 2021 were included. Demographic information, comorbidities, laboratory parameters, dabigatran indication, anticoagulation resumption, adverse events related to idarucizumab and death within 30 days were collected from medical records. Qualitative data are presented as frequencies and percentages. Quantitative data are presented as mean ± standard deviation (SD) or median (interquartile range -IQR-). Cumulative survival was calculated by dividing the number of patients alive by the number of patients in each indication category for idarucizumab in a 30-day post-infusion period.
Results: A total of 69 patients from 8 hospitals in Madrid were included. Ninety-six percent received dabigatran for prevention of stroke and embolism in nonvalvular atrial fibrillation and 4% received it for the treatment of thromboembolic disease. The mean age was 73.5 ± 13.9 years, and 55.6% were men. Median aPTT was 45.6 seconds and was prolonged in 72.1% (49). Patient characteristics, concomitant conditions and laboratory parameters are reviewed in Table 1.
The main indication for idarucizumab was reversal of anticoagulation for persistent bleeding (46.4%), followed by surgery (44.9%). Fibrinolysis due to ischemic stroke was performed in 3 patients (4.3%), dabigatran intoxication occurred in 3 patients due to acute renal failure (4.3%). Gastrointestinal bleeding was the most common type of bleeding. Two of the patients intoxicated with dabigatran also had gastrointestinal bleeding. Cardiac surgery was the most common type of intervention, with heart transplant being a common indication (9/13). Minor surgical procedures included 2 lumbar punctures and 1 central venous catheterization. In one case, the type of surgery was not available. Figure 1 A and B summarize the bleeding location and type of surgery.
The median time between infusion of idarucizumab and cessation of bleeding or onset of surgery was 3 hours, however this information was only available in 43 patients. No reports of excessive bleeding during surgery or after fibrinolysis were noted. One patient with dabigatran intoxication was reported to have an episode of persistent melena in which the trough plasma level was 1178.1 ng/mL. This patient died of an aggressive lymphoproliferative disorder that couldn´t be biopsied due to altered coagulation. A case of auricular thrombosis occurred in a patient with a heart transplant due to hyperthophic cardiomiopathy and end-stage heart failure requiring thrombectomy. The patient required a biventricular assistance and died of myocardial infarction.
Full 30-day follow-up was available for 68 patients, during this period 11 died. Five patients in the bleeding group died, 3 from hypovolemic shock, 1 from intraparenchymal hemorrhage and data were missing for 1. Two patients who received a heart transplant died, one as described previously 10 days after the transplant and the other 2 days after the transplant from hemorrhagic shock. Three patients who underwent abdominal surgery died of septic shock. One patient with dabigatran intoxication died. Cumulative survival after a follow-up period of 30 days was 86% (Figure 2).
Seventy-seven percent (53) resumed anticoagulation after a median of 3 days (0-180), and 62.3% (33) were bridged with low molecular weight heparin (LMWH) at prophylactic doses. Finally, 75% (40) maintained LMWH (7) or restarted dabigatran or another direct oral anticoagulant (33). A total of 13 patients didn´t resume any anticoagulation.
Conclusions: Idarucizumab is an effective drug for reversal of dabigatran anticoagulation in bleeding or imminent surgery/invasive procedures. In this cohort it was used safely in patients awaiting a heart transplant. No cases of bleeding after infusion or during surgery were reported, except for a single case of auricular thrombosis. Most patients resumed anticoagulation at discharge. The experience described confirms the safety of idarucizumab in daily clinical practice.
Figure 1 Figure 1.

Disclosures
No relevant conflicts of interest to declare.