Comparison of Viscoelastic Testing by Rotational Torsion and Harmonic Resonance Methods: Two-Center Comparison of TEG 5000 and TEG 6S Instruments

Objectives: To compare the performance of the TEG 5000 and TEG 6S Global Hemostasis cartridge. Methods: We reviewed validation data of the TEG 5000 and TEG 6S Global Hemostasis cartridge. The specimens were analyzed in parallel according to the manufacturer's operating instructions. Results: Fifty-four healthy donors and 13 donors with known hemostatic abnormalities were included. The correlations between instrument types were only moderate--the Spearman rank correlations were 0.55, 0.62, 0.64, and 0.72, respectively, for CK R, K, angle, and maximum amplitude (MA) parameters. Using the manufacturer's device-specific reference ranges to classify results as normal/abnormal, there was weak agreement in the qualitative interpretation of all parameters (Cohen's [kappa] for agreement for CK R, K, angle, and MA was 0.418, 0.154, -0.083, and 0.127, respectively). This could lead to discordant transfusion decisions. Conclusions: These findings indicate that the TEG 5000 and TEG 6S may not be used interchangeably.