Abstract Number: PB0331
Meeting: ISTH 2021 Congress
Background: The GEM Hemochron 100 is a point of care (POC) coagulation analyzer that performs individual ACT tests on fresh whole blood samples. It is the next generation Hemochron device following the on-market Hemochron Signature Elite. There are two ACT cartridges available for the system, ACT+ and ACT-LR, which demonstrate linear correlation to the anticoagulation effects of heparin from 1.0 up to 6.0 U/mL and 0 up to 2.5 U/mL, respectively.
Aims: To demonstrate that ACT results reported by the GEM Hemochron 100, over the ACT+ and ACT-LR reportable ranges, are equivalent to the results given by the Hemochron Signature Elite. To evaluate the precision of the system for each assay.
Methods: Method comparison testing was performed to evaluate the GEM Hemochron 100 system, in a multi-site clinical study utilizing the Hemochron Signature Elite as the predicate device. Patient blood samples were tested in duplicate on paired instruments. Data analysis included Passing-Bablok regression, calculation of the Pearson product-moment correlation coefficient (r), and determination of the percentage bias at medical decision levels. A liquid quality control (LQC) precision study was also performed, and fully nested variance components models were employed for analysis.
Results: Table 1 summarizes the method comparison study results and Table 2 summarizes the LQC precision study results.
| Assay Type | N | Metric | Result (95% CI) |
| ACT+ (Pooled, First Replicate) |
1279 | Passing-Bablok Slope | 1.04 (1.03-1.06) |
| Correlation Coefficient, r | 0.95 | ||
| ACT-LR (Pooled, First Replicate) |
463 | Passing-Bablok Slope | 0.96 (0.93-1.00) |
| Correlation Coefficient, r | 0.95 |
Clinical Method Comparison Summary, GEM Hemochron 100 vs. Hemochron Signature Elite
| Within Run (Repeatability) | ||||||
| LQC Level | N | Mean | SD | %CV | ||
| ACT-LR Level 1 | 640 | 176.3 | 14.2 | 8.1% | ||
| ACT-LR Level 2 | 640 | 294.5 | 16.8 | 5.7% | ||
| ACT+ Level 1 | 640 | 158.9 | 12.5 | 7.9% | ||
| ACT+ Level 2 | 640 | 447.7 | 10.4 | 2.3% | ||
Liquid Quality Control (LQC) Precision Summary from 20 Day Study
Conclusions: The GEM Hemochron 100 ACT+ and ACT-LR results are equivalent to the results given by the Hemochron Signature Elite. The assay systems yielded precision estimates in %CV below 10% and can be used to assess response to unfractionated heparin in many clinical applications.
The clinical study did not require written Informed Consent in alignment with FDA guidance provided in 71 FR 23924. It was performed under the oversight of, and after approval by, the appropriate Institutional Review Boards.
To cite this abstract in AMA style:
Leung A, Lu W, Martin M, Smith C, Diggs J, Chen S, Yu P, Bottenus R. Evaluation of Activated Clotting Time (ACT) Results on a New POC Coagulation Analyzer [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/evaluation-of-activated-clotting-time-act-results-on-a-new-poc-coagulation-analyzer/. Accessed January 23, 2022.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/evaluation-of-activated-clotting-time-act-results-on-a-new-poc-coagulation-analyzer/