Abstract Number: PB2385
Meeting: ISTH 2020 Congress
Theme: Venous Thromboembolism and Cardioembolism » VTE Prophylaxis
Background: Intravenous unfractionated heparin (UFH) is administered routinely in the intensive care unit (ICU) for anticoagulation of patients. UFH doses are adjusted based on the monitoring of activated partial thromboplastin time (APTT) or anti-Xa activity. However, these strategies are associated with potentially large time intervals before dose adjustments, which could be detrimental to the patient.
Aims: To compare a point-of-care (POC) version of APTT to (i) laboratory-based APTT and (ii) measurement of anti-Xa activity in terms of agreement and turnaround time (TAT).
Methods: Seventeen ICU patients requiring UFH therapy for at least 72 hours either for preventive anticoagulation (n=10) or therapeutic anticoagulation (n=7) were prospectively included after giving their written informed consent. UFH was administered according to a local adaptation of Raschke and Amanzadeh algorithms. UFH doses were adjusted on laboratory APTT for therapeutic (2.0-2.5 times baseline APTT) or prophylactic (1.5-2.0 times baseline APTT) anticoagulation. Simultaneous measurements of POCT-APTT (CoaguChek® Pro II, Roche Diagnostics) on a drop of fresh whole blood, laboratory-based APTT (C.K. Prest®, Stago) and Anti-Xa activity (STA®Liquid anti-Xa, Stago) on 3.2% buffered citrated plasma were systematically measured before dose adjustment. Agreement was evaluated in ten patients for whom both POCT and laboratory APTT before UFH administration were available.
Results: The relationship between POCT-APTT vs laboratory APTT (n=162 pairs) and POCT-APTT vs Anti-Xa (n= 117 pairs) for both therapeutic and prophylactic ranges are presented in Figure 1. There was no inter-method agreement between POCT vs laboratory APTT (Cohen´s kappa -0.031 (95%CI -0.12-0.06; p=0.51), and between POCT vs Anti-Xa activity (Cohen´s kappa -0.033 (IC95% -0.18;0.11; p=0.66). Global TAT from blood collection until dose adjustment based on laboratory APTT was 101.3 ± 44.8 minutes (mean±sd; Table 1).
Conclusions: Based on these preliminary results, no agreement between POCT-APTT and either laboratory APTT or Anti-Xa activity was identified. However, these latter methods were associated with high TATs. 
[Figure 1]
[Table 1]
To cite this abstract in AMA style:
Lardinois B, Hardy M, Lessire S, Michaux I, Rotens T, Horlait G, Bareille M, Jacqmin H, Mullier F, Dive A-. Point-of-Care Monitoring of Unfractionated Heparin Treatment in the Intensive Care Unit: Preliminary Results of a Comparative Study with Laboratory-based APTT and Anti-Xa Activity [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/point-of-care-monitoring-of-unfractionated-heparin-treatment-in-the-intensive-care-unit-preliminary-results-of-a-comparative-study-with-laboratory-based-aptt-and-anti-xa-activity/. Accessed September 22, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/point-of-care-monitoring-of-unfractionated-heparin-treatment-in-the-intensive-care-unit-preliminary-results-of-a-comparative-study-with-laboratory-based-aptt-and-anti-xa-activity/