Abstract Number: PB0575
Meeting: ISTH 2020 Congress
Background: The T-TAS01 PL assay is a novel in vitro diagnostic system that passes whole blood through a collagen-coated microcapillary bed at arterial shear stress to measure the platelet thrombus formation process. The test is used to assess overall primary hemostatic function. Results are reported as the area under the pressure-time curve (AUC).
Aims: To validate the diagnostic performance of the T-TAS01 PL assay using a pre-specified AUC< 260 cutoff in subjects taking antiplatelet therapy.
Methods: Healthy subjects and subjects confirmed to be taking 81-325 mg daily aspirin monotherapy (ASA) or dual antiplatelet therapy (DAPT) were enrolled according to an IRB-approved protocol at three investigational sites. Blood samples were collected into vacuum tubes containing benzylsulfonyl-D-Arg-Pro-4-amidinobenzylamide (BAPA), a thrombin and factor Xa inhibitor. Healthy subjects were screened for possible primary hemostasis defects and confirmed to have normal primary hemostatic function.
Results: 259 subjects were enrolled. The T-TAS01 PL AUC< 260 cutoff was 96% specific, and 71% and 100% sensitive for abnormal primary hemostatic function in ASA and DAPT patients, respectively. The AUC results correlated with the potency of antiplatelet therapy, as well as vWF antigen and activity levels. The AUC>260 results in aspirin patients reflect the established variability in response to aspirin and existence of poor response or “aspirin resistance”. Subjects taking ticagrelor DAPT had lower AUC results compared to subjects taking clopidogrel DAPT (mean AUC 46.2 vs 20.7) and had significantly less variability in AUC results (p < 0.01).
Conclusions: The T-TAS01 PL assay is highly sensitive and specific for impaired primary hemostatic function caused by antiplatelet therapy, and AUC results decrease in proportion to the potency of antiplatelet therapy. T-TAS01 PL assay measurements may be useful for the assessment of overall primary hemostatic function in patients taking antiplatelet therapy either while on therapy or following cessation prior to procedures involving bleeding risk.
| Group | N | Mean Age | % Female | Mean AUC | % < 260 AUC |
| Healthy Controls | 142 | 38 | 67.6% | 381.5 | 4.2% |
| ASA | 82 | 67 | 34.1% | 221.0 | 70.7% |
| DAPT | 35 | 63 | 25.7% | 33.8 | 100.0% |
[Summary Data]
To cite this abstract in AMA style:
Dahlen J, Gurbel P, Wu AHB, Bliden K, Ong C-, Tantry U, Hosokawa K. Clinical Validation of the T-TAS 01 PL Assay in Patients Taking Antiplatelet Therapy [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/clinical-validation-of-the-t-tas-01-pl-assay-in-patients-taking-antiplatelet-therapy/. Accessed September 24, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/clinical-validation-of-the-t-tas-01-pl-assay-in-patients-taking-antiplatelet-therapy/