Clinical review: Clinical management of new oral anticoagulants: a structured review with emphasis on the reversal of bleeding complications

Table 2 Effects of new anticoagulants on common coagulation tests

Test	Dabigatran etexilate	Rivaroxaban or apixaban
Activated partial thromboplastin time	Prolongation, variation among reagents	Prolongation, variation among reagents
Prothrombin time (Quick method)^a	Prolongation	Prolongation
Prothrombin time (Owren method)^a	Prolongation	Prolongation
Fibrinogen (Clauss method)	Moderate to marked underestimation	Minimal effect
Thrombin time	Marked prolongation	Minimal effect
Hemoclot thrombin inhibitor assay	Prolongation	Not applicable
International normalized ratio (point-of-care)	Elevation	Elevation?^b
Activated factor × (FXa) activity	Minimal effect	Marked overestimation
HepTest assay for monitoring heparin in plasma and whole blood	Not applicable	Marked, dose-dependent overestimation

^aThere is significant variability in prothrombin time and international normalized ratio (INR) prolongation, depending on the reagents used and the time of administration of the drug. INR results might be elevated, ranging from 1.2 to more than 3.0. ^bNo available information. Adapted from [2, 17, 21, 56, 62–69].

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