Acute cardiac care & resuscitation
Discordance Between Activated Partial Thromboplastin Time (aPTT) and Anti-Xa in Monitoring Heparin Anticoagulation in Mechanical Circulatory Support
Authors' conclusion
aPTT and anti-Xa were frequently discordant in MCS patients receiving heparin anticoagulation. Clinical conditions common in MCS patients such as concurrent warfarin use, malnutrition, haemolysis, and thrombocytopenia, as well as durable type of MCS devices were associated with a high aPTT relative to anti-Xa.
Study context
- Population
- Mechanical circulatory support (MCS) patients receiving unfractionated heparin23,001 paired measurements
- Participants
- 699 participants
- Exposure
- aPTT vs anti-Xa for monitoring unfractionated heparin
- Outcome
- Concordance between aPTT and anti-Xa (both subtherapeutic, therapeutic, or supratherapeutic) and predictors of discordance
Methodological detailssingle-centre, tertiary academic medical centre
- Single-centre
- Tertiary academic medical centre
Main finding
As reported in the abstract
aPTT/anti-Xa concordance (paired observations)
Concordant
35.5%
Discordant
64.5%
Discordant, aPTT > antiXa
61.5%
Discordant, aPTT < antiXa
3.0%
Observational data: associations, not effects.
Further findings
Predictors of discordance with aPTT > anti-Xa (random forest and multivariate regression)
- Associated with high INR, eGFR and total bilirubin, and low platelets, haemoglobin, pre-albumin, white blood cell count and haptoglobin
- Total artificial heart and durable ventricular assist devices more likely associated with aPTT > anti-Xa than temporary MCS devices
Original publication
Discordance Between aPTT and Anti-Xa in Monitoring Heparin Anticoagulation in Mechanical Circulatory Support. ESC Heart Fail. Published 9 May 2024. doi:10.
Summarised from the published abstract; every number is checked against it