Anticoagulant Therapy

ISTH Covid Antithrombotics Guidelines

On Wednesday, 8-3-22, the ISTH published comprehensive guidelines recommending for or against antithrombotic agents for Covid at defined levels of severity. Below are the task force guidelines and an editorial describing the research considerations behind guideline development. Schulman S, Sholzberg M, Spyropoulos AC, et al. ISTH guidelines for antithrombotic treatment in COVID-19. JTH 2022, DOI: […]

Anticoagulant Therapy

Heparin Curve to Measure DOACs?

Does your facility measure rivaroxaban or apixaban using a chromogenic substrate anti-Xa assay based on unfractionated heparin [UFH] calibrators or UFH-low molecular weight heparin [UFH-LWMH] ‘hybrid” calibrators, or do you require rivaroxaban and apixaban calibrators? I [Geo] received a 6-22-22 response from international hemostasis expert Robert Gosselin, who cited several references. Many of us use […]

Anticoagulant Therapy

April 2022 QQ: Measuring Heparin Summary

Hello, our April 2022 Quick Question asks, “How do you measure unfractionated heparin [UFH]?” Our 37 respondents answered… Chromogenic anti-Xa using a hybrid curve: 38% [14] Chromogenic anti-Xa using the UFH curve: 14% [5] Anti-Xa and PTT: 22% [8] PTT: 26% [9] The majority of respondents are using the chromogenic anti-Xa heparin assay, and most […]

Anticoagulant Therapy

April 2022 QQ: Measuring Heparin

Our April 2022 Quick Question reprises our May 16, 2012 post, “Who Uses the Hybrid Curve?” but adds a twist based on May JE, Siniard RD, Taylor LJ, Marques MB, Gangaraju R. From activated partial thromboplastin time to anti-factor Xa and back again; the evolution of monitoring unfractionated heparin. Am J Clin Pathol 2022;157:321–7 HTTPS://DOI.ORG/10.1093/AJCP/AQAB135. […]

Anticoagulant Therapy

March 2022 Quick Question Summary

The stem of our March 2022 Quick Question was, “How do you measure the anti-Xa DOACs rivaroxaban or apixaban?” The question drew 33 responses and here are the answer selections: We don’t measure the anti-Xa DOACs: 24% [8] Chromogenic anti-Xa using DOAC-specific calibrators and controls: 64% [21] Chromogenic anti-Xa using the unfractionated heparin curve: 3% […]

Anticoagulant Therapy

March 2022 Quick Question: Measuring Anti-Xa DOACs

Please review and answer our March 2022 Quick Question, submitted by colleague and coagulation expert Dave McGlasson. Although the US FDA has never approved the chromogenic anti-Xa assay for the direct oral anticoagulants rivaroxaban and apixaban, calibrators and controls are available from several distributors. Many facilities are called upon to assay for plasma concentration in […]

Anticoagulant Therapy

Measuring DOACs

Here is a helpful article from the January 17, 2022 issue of CAP Today: “Measuring Direct Oral Anticoagulants—When, How.”

Anticoagulant Therapy

PIVKA

George is updating a book chapter and asks if there is a reason to continue using the phrase “proteins induced by vitamin K absence/antagonists” [PIVKA], now termed des-gamma-carboxy- II, VII, IX, or X. Does any laboratory continue to offer a PIVKA assay?

Anticoagulant Therapy

The Fiix-PT Assay; Improves on PT-INR?

I [Geo] received a communication from Dr. Pall Onundarson, Hematology Laboratory and Thrombosis and Hemostasis Service, Faculty of Medicine, University of Iceland, Reykjavik, Iceland, about the Fiix-PT assay designed to monitor vitamin K antagonist [warfarin, Coumadin] therapy unaffected by reductions in FVII and FIX which the authors claim to play little role in clinical anticoagulation. […]

Anticoagulant Therapy

December 2021 Quick Question: Thrombosis Risk Profile

Our December 2021 question asks, “The resident orders a thrombosis risk profile on an inpatient being treated for a pulmonary embolism [PE]. How do you respond?” This question is inspired by a case study we developed for Rutgers’ CLSC 5124 Advanced Hemostasis fall, 2021 online graduate course. Above is a screen capture that lists several […]

Anticoagulant Therapy

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George Fritsma is a medical laboratory scientist, educator, and author. George holds faculty appointments with Rutgers University and Michigan State University, and is a member of the International Society on Thrombosis and Hemostasis, American Association of Clinical Chemists, and American Society for Clinical Laboratory Science.

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