- We strive to improve the clinical outcome of patients at risk of thromboembolic disorders.
- The efficacy and safety of treatment with coumarins (vitamin K antagonists; VKA, mainly warfarin) is totally dependent on monitoring their anticoagulant effect with coagulation tests, the Quick prothrombin time (Quick PT) or less commonly the Owren prothrombin time (Owren PT/P&P test). Based on experiments we invented and tested a modified PT, the Fiix-prothrombin time (Fiix-PT, Fiix-INR). The Fiix-PT was mainly intended to improve warfarin management but later experiments show that a modified dilute Fiix-PT can also be used to measure new anticoagulant agents such as direct oral anticoagulants (DOACs).
- The results of a large blinded randomized clinical trial, the Fiix-trial, were published in the 2015 June issue of The Lancet Haematology and shows that compared to monitoring warfarin with high quality (TTR 80%) PT monitoring, monitoring with the Fiix-PT leads to improved stability of warfarin anticoagulation and up to 50% reduction in thromboembolic events without an increase in major bleeding. The need for dose adjustments and test frequency was reduced. Overall, the results suggest that the fluctuation typically observed during warfarin treatment is partly caused by the influence of factor VII on the traditional prothrombin time itself and that replacing traditional PT (INR) monitoring of VKA with the Fiix-PT improves warfarin as an anticoagulant agent.
- Our estimations suggest that the Fiix-PT would not be substantially more expensive than the currently available PT. Therefore, improved warfarin management by montoring with the Fiix-PT should be of interest to patients, caretakers and third-party payers as well as society at large as the continued use of warfarin in many patients would prevent substantial cost increases associated with use of newer oral anticoagulant agents. In light of the enhanced efficacy, warfarin monitored with the Fiix-PT (“Fiix-warfarin”) could become an important oral anticoagulant choice.