Dabigatran: Is There a Role for Coagulation Assays in Guiding Therapy?

OBJECTIVE: To determine the usefulness of coagulation assay monitoring for dabigatran etexilate in certain high-risk clinical situations. DATA SOURCES: Literature retrieval was accessed through MEDLINE (1948-February 2013), Web of Science (1980-February 2013), International Pharmaceutical Abstracts (1977-February 2013), and Google Scholar using the terms dabigatran, dabigatran etexilate, BIBR 1048, BIBR 953, direct thrombin inhibitor, therapeutic monitoring, and atrial fibrillation. In addition, abstracts presented at the 2011-2012 American Society of Hematology, American College of Cardiology, International Society of Thrombosis and Haemostasis, and European Society of Cardiology annual meetings were reviewed. A search of Clinicaltrials.gov was performed to identify relevant ongoing or completed research. STUDY SELECTION AND DATA EXTRACTION: All English-language articles identified from the data sources were evaluated for inclusion. Priority was placed on all data derived from controlled clinical studies. DATA SYNTHESIS: Of the 6 published Phase 3 studies, only the RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial evaluated the safety and efficacy of dabigatran for the prevention of stroke in patients with nonvalvular atrial fibrillation. Post hoc analyses of the RE-LY trial have provided additional information in special situations. Several published reports highlight the potential for complications with dabigatran, the importance of determining the most optimal candidates, and the need for therapeutic monitoring. Activated partial thromboplastin time and thrombin time are effective qualitative assays for dabigatran. Ecarin clotting time and the dilute thrombin time (ie, Hemoclot direct thrombin inhibitor) assays are suitable for quantitative measurement. CONCLUSIONS: The correlation between coagulation-based assays and clinical out comes among dabigatran-treated patients has not been definitively established. However, coagulation-based assays may be useful in the management of several clinical scenarios.