May 2017:
In a publication in the Journal of Thrombosis and Thrombolysis it was demonstrated that stabilization of anticoagulation by Fiix-PT monitoring associated with reduced thromboembolism compared to standar PT (INR) monitoring.

Reduced anticoagulation variability in patients on warfarin monitored with Fiix-prothrombin time associates with reduced thromboembolism: The Fiix-trial.

Oskarsdottir AR, Gudmundsdottir BR, Indridason OS, Lund SH, Arnar DO, Bjornsson ES, Magnusson MK, Jensdottir HM, Vidarsson B, Francis CW, Onundarson PT.
J Thromb Thrombolysis. 2017 May;43(4):550-561. doi: 10.1007/s11239-017-1482-4.

January 2017:
This publication published in January 2017 in the Journal of Thrombosis and Haemostasis demonstrates that the Fiix-PT reflects thrombin generation better than does the standard prothrombin time in samples from patients on warfarin. Thus, the results support the hypothesis that the practice of using a monitoring test that is affected by FVII should be abandonded.

During warfarin induction, the Fiix-prothrombin time reflects the anticoagulation level better than the standard prothrombin time.

Jonsson PI, Letertre L, Juliusson SJ, Gudmundsdottir BR, Francis CW, Onundarson PT.
J Thromb Haemost. 2017 Jan;15(1):131-139. doi: 10.1111/jth.13549. Epub 2016 Nov 30.

July 24 2016:
A meta-analysis published in the International Journal of Laboratory Haematology suggests that monitoring warfarin with Fiix-PT reduces risk of vascular events in NVAF patients at least as much as DOACs.
Compared to traditionally INR monitored warfarin, Fiix-warfarin (warfarin monitored with Fiix-PT) is an improved anticoagulant.

June 7 2016:
A publication in the May 2016 issue of the Journal of Thrombosis and Haemastasis demonstrates that the dilute Fiix prothrombin time may be suitable as a stat test to assess all oral anticoagulants as well as unfractionated and fractionated heparin.

Pall T. Onundarson, M.D. ( and Brynja R. Gudmundsdottir, M.S. (
+534-543-5010 (Pall) and +534-861-2662 (Brynja) Email:
Holtsvegur 45, ibud 501, 210 Gardabaer, Iceland