The ability to explain bleeding or clotting complications in patients treated with dabigatran remains challenging. In addition, there is limited data on how coagulation tests perform in patients treated with therapeutic doses of dabigatran. Predicted responses of coagulation tests to therapeutic doses of dabigatran may be helpful in better understanding abnormal responses to dabigatran. The purpose of the study is to define a therapeutic reference range for peak and trough coagulation tests in patients taking FDA approved doses of dabigatran and to determine which tests may be most clinically useful for monitoring dabigatran.

Inclusion Criteria:

• Medication therapy with dabigatran 75 mg twice daily or 150 mg twice daily for a minimum of 3 days

Exclusion Criteria:

• CrCl < 15 ml/min
• Non-FDA approved dose based on calculated CrCl with most recent SCr
• Age < 18 years
• Inability to communicate in the English language
• Decisionally-impaired individuals
• Incarcerated
• Pregnant/Lactating (Pregnancy category: C, unevaluated effects in lactation)

Patients taking FDA-approved doses of dabigatran and control subjects not taking an anticoagulant or antiplatelet were eligible for inclusion.