Replacement of traditional prothrombin time monitoring with the new Fiix prothrombin time increases the efficacy of warfarin without increasing bleeding. A review article

Figures

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  Fig. 1. Influence of selective reduction in vitamin K dependent factors, a single factor at a time while others remain within normal range, on the undiluted Quick prothrombin time (Neoplastin with ISI 1.3, Stago, Asnieres, France: panel A) and and automated peak thrombin generation with clotting activated with a diluted thromboplastin (Neoplastin diluted 1:17,000: panel B) The figures are reproduced with permission from Thrombosis Research 2012;130:674–81 [3] and Journal of Thrombosis and Haemostasis 2016;15:131–9, respectively [41].

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  Fig. 2. Correlation of Fiix-normalized ratio with undiluted Owren’s PT-INR (SPA, Stago, Asnieres, France: upper panel) or undiluted Quick PT-INR (Neoplastin, Stago, Asnieres, France: lower panel) in samples from patients on stable warfarin therapy. Previously unpublished data from the study described in Thrombosis Research 2012;130:674–81 [3].

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  Fig. 3. Examples of differences in PT-INR and Fiix-NR during warfarin initiation when factor VII is fluctuating due to dose changes. Both the PT-INR and Fiix-NR were measured using undiluted Neoplastin CI Plus with ISI 1.3 (Diagnostica Stago, Asnieres, France) but in the Fiix-NR measurement factor II and X deficient plasma is added to diluted test plasma prior to addition of Neoplastin. Reproduced with permission from Thrombosis Research 2012;130:674–81 [3]

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  Fig. 4. Cumulative non-fatal and fatal thromboembolic events (panel A) and major bleeding (panel B) during treatment days 1–720 of the randomized double blind Fiix trial in patients monitored either with Fiix-warfarin (blue) or PT-warfarin (red). Reproduced with permission from The Lancet Haematology 2015;2:e231-e40 [35].

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  Fig. 5. Relative risk plots showing major vascular event rates and relative risk plots comparing clinical outcome during Fiix-NR or traditional PT-INR. Reproduced with permission from Blood 2021;137 [20]:2745–55 [36].