Comparative evaluation of routine coagulation testing on Stago sthemO 301 and Werfen ACL TOP 750

Objectives: We performed a comparative evaluation of analytical performance between the novel bench-top Stago sthemO 301 hemostasis analyzer and the Werfen ACL TOP 750 coagulometer using routine plasma samples. Methods: A minimum of 100 fresh plasma samples per test were analyzed using both analytical systems. The tests included prothrombin time (PT) expressed as international normalized ratio (INR) and seconds (s), activated partial thromboplastin time (APTT) in ratio and seconds, fibrinogen, antithrombin and D-dimer. Clotting assays were performed using mechanical clot detection on sthemO and optical detection on ACL TOP. The comparative evaluation included the calculation of Spearman's correlation, Passing-Bablok regression and Bland-Altman plots. Results: Correlation coefficients ranged between 0.76 for APTT to 0.98 for PT-INR and D-dimer, indicating a generally acceptable/good agreement. The regression slopes varied from 0.82 for D-dimer to 1.17 for APTT-s. A significant bias was observed for all tests except antithrombin, with differences for sthemO ranging between -31 % for D-dimer and 13.7 % for PT-s. Conclusions: SthemO demonstrates acceptable global comparability with ACL TOP for routine coagulation testing. Nevertheless, reagent- and method-dependent bias has been observed, which highlight the need for additional harmonization efforts.