Abstract Number: PB0641
Meeting: ISTH 2020 Congress
Background: Screening coagulation assays (PT/PTT) have poor sensitivity and specificity for detection of hemostatic defects. We have developed a novel, point-of-care (POC), whole blood assay based on a dielectric microsensor (ClotChip) that provides global coagulation assessment in a miniaturized, portable measurement platform
Aims: To assess the ClotChip sensitivity to detect hemostatic defects
Methods: Patients (n=37) presenting with bleeding symptoms or with abnormal coagulation screening pre-operatively, and undergoing a bleeding disorder work-up, were enrolled. Blood samples were obtained by venipuncture in 3.2% sodium citrate. Coagulation was induced with CaCl2. ClotChip was based on the electronic technique of dielectric spectroscopy (DS) integrated into a disposable microfluidic channel with < 10 µL sample volume. ClotChip curves were calculated as variation in blood permittivity at 1MHz, and time to reach a peak in permittivity (Tpeak) was taken as coagulation time. Sensitivity and specificity of ClotChip were calculated for detection of a hemostatic defect
Results: ClotChip exhibited mean Tpeak of 435 ± 22 sec (mean ± SEM) for patients with clinically normal hemostatic function. Mean Tpeak for patients with a hemostatic dysfunction was 751 ± 159 sec and was significantly prolonged (P=0.002) compared to patients in the normal group. A receiver operator characteristic (ROC) curve (Fig. 1)
[ROC Curve]
was generated to determine the true-positive rate (sensitivity) and false-positive rate (100% – specificity) for ClotChip Tpeak to detect hemostatic dysfunction, and the area under the curve (AUC) for ClotChip Tpeak was 0.88. The sensitivity and specificity of ClotChip Tpeak with a threshold of 540 sec were determined as 78% and 93%, respectively (Table 1)
Hemostatic Defect Present | Hemostatic Defect Absent | Total | |
ClotChip Abnormal | 7 (True Positive) | 2 (False Positive) | 9 |
ClotChip Normal | 2 (False Negative) | 26 (True Negative) | 28 |
Total | 9 | 28 | 37 |
[Sensitivity and Specificity Results]
Conclusions: Our studies demonstrate a novel, microfluidic, dielectric sensor (ClotChip) was sensitive for detection of hemostatic defects. ClotChip has potential to fulfill an unmet clinical need as a POC tool to triage extensive work-up for bleeding symptoms or abnormal coagulation screening tests
To cite this abstract in AMA style:
Pourang S, Suster M, Maji D, Butala S, Nutt J, Nayak L, Mohseni P, Ahuja S. A Novel Point-of-Care Whole Blood Coagulation Assay to Screen for Hemostatic Defects [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/a-novel-point-of-care-whole-blood-coagulation-assay-to-screen-for-hemostatic-defects/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/a-novel-point-of-care-whole-blood-coagulation-assay-to-screen-for-hemostatic-defects/