Table 2

Coagulation assays responsive to dabigatran, rivaroxaban, apixaban and edoxaban

AssayResponsive within therapeutic range?Included in US drug prescribing information?*
Dabigatran22–24 26 28 45–47
 aPTTProvides estimate of effectYes
 ECTQuantifiable dose–responseYes
 TTToo sensitive to give quantifiable resultsNo
 Diluted TTQuantifiable dose–responseNot in the USA
Rivaroxaban29–31 48–52
 PT (rivaroxaban-calibrated)Quantifiable dose–response if PT performed with neoplastinYes
 aPTTDose-dependent, but variable and less sensitive than PTNo
 FXa (clot-based, eg, HepTest)Quantifiable dose–responseNo
 FXa (chromogenic)Quantifiable dose–responseNo
Apixaban42 43 53 54
 PT/INRSmall and variable responseNo
 aPTTSmall and variable responseNo
 FXa (chromogenic)Quantifiable dose–responseNo
 PTLarge variability between reagentsNo
 aPTTLess variability between reagentsNo
 Thrombin generationThree times more sensitive to edoxabanNo
  • Assays that can give quantifiable responses will typically require drug-specific and laboratory-specific calibration.

  • *Routine use of coagulation assays is not required with the novel oral anticoagulants.

  • aPTT, activated partial thromboplastin time; ECT, ecarin clotting time; FXa, factor Xa; INR, international normalised ratio; PT, prothrombin time; TT, thrombin time.