Comparison between the automated TEG®6s and viscoelastic analyzer Haema T4.

Background: Viscoelastic testing is increasingly being used for point-of-care coagulation management. This study compared the Haema T4 (HT4, Medcaptain®), a novel viscoelastic analyzer, with the TEG®6s (Haemonetics®), as they use similar assays but different measurement technologies. Methods: Combined extrinsic-intrinsic activation (CRT), intrinsic activation (CK/kaolin), and fibrinogen polymerization (CFF/FIB) assays were performed using both devices. Activated clotting time (ACT), reaction time (r-time), kinetic time (k-time), and maximum amplitude (MA) were assessed under various experimental conditions. Results: The TEG®6s delivered higher absolute values for ACT, r-time, and k-time but lower MA values than the HT4. A weak correlation for ACT was demonstrated between the devices for the CRT assay (r = 0.36, 95% CI: 0.08-0.59, P = 0.011), with wide limits of agreement (-23.4 to 146.6 s) and substantial bias (61.6 ± 43.4 s). In contrast, strong correlations for MA were demonstrated for the CRT (r = 0.91, 95% CI: 0.84-0.95) and CK/kaolin assays (r = 0.95, 95% CI: 0.91-0.97), with minimal bias (-1.2 ± 5.6 mm and -4.8 ± 2.3 mm, respectively). For the CFF/FIB assays, MA displayed a strong correlation (r = 0.85, 95% CI: 0.75-0.92) with a bias of -5.9 ± 8.6 mm. Conclusions: Although several parameters showed a strong correlation, agreement between the HT4 and TEG®6s was limited, indicating that results between the devices are not interchangeable. Device-specific reference ranges must be determined and clinical outcome studies are required before incorporating the HT4 into clinical practice.