Point-of-care testing for emergency assessment of coagulation in patients treated with direct oral anticoagulants
Critical Care 2017;21:32 doi:10.1186/s13054-017-1619-z
Presented by: Dr B Eagle
- The use of direct oral anticoagulants (DOAC) is increasing, yet there is no way to point of care test coagulation in patients taking these drugs.
- Haemochron signature is a coagulation point of care test (POCT) that is sensitive to rivaroxaban and dabigatran, although its action on apixiban is unreported.
- This study aims to evaluate the use of haemochron in guiding emergency treatment of DOAC treated patients.
Design & Setting
- Prospective observational single centre study based in Tubingen Germany.
- Patients enrolled receiving first dose of apixiban, rivaroxaban or dabigatran.
- Patients excluded with any form coagulopathy or on other anticoagulants.
- 60 patients enrolled.
- Samples of blood taken from each subject before DOAC intake and at intervals up to 24 hours post ingestion.
- Bedside POCT testing using Haemochron was undertaken – PT/INR, aPTT, ACT.
- Lab anti 10a concentrations were measured and liquid chromatography with mass spec used to determine concentrations as a gold standard.
- Analyses used to determine whether POCT can determine concentrations considered safe for emergency surgery and for stroke thrombolysis i.e. POCT PT of 1 equates to concentration of 30ng/ml for rivaroxban – considered the safe threshold for operations.
- Correlation between POCT and apixiban concentrations were weak for PT/INR and moderate for ACT.
- No correlation for aPTT.
- Rivaroxaban correlation strong for PT/INR and ACT and weak for aPTT.
- Dabigatran correlated strongly with all assays.
- Hemochron POCT testing correlates with rivaroxaban and dabigatran concentrations but not apixiban concentrations.
- POCT specific cut offs can be used to exclude rivaroxaban concentrations at the bedside with high specificity.
- Good sample numbers
- Novel idea, to help with a clinically relevant problem
- Essentially a lab study – using whole blood – tests not been used to actually guide any clinical intervention
- This study does not help to determine what the clinically relevant concentrations of these drugs are – even though it can test for arbitrarily determined levels
- Study does not discuss how Haemochron differs in effectiveness from established POC testing such as TEG or ROTEM
Implications & Potential for Impact
- Haemochron signature could be used to rule out relevant concentrations of rivaroxaban and dabigatran.
- May allow concentration based cut offs for operating on patients on DOACS to be used rather than time based cut offs currently used – time based estimation may be very variable