Table 3.
A description of the four standard VHA assay parameters and their clinical significance with the addition of the most recent tools for measuring POC clot dynamics with the TEG® 5000, TEG® 6s, ROTEM® delta/sigma, Quantra® QPlus®, and the ClotPro® systems [18,27,53,59,65,68,69,70,71,72,73,74].
| Coagulation Event | Main Contributor | TEG® 5000 | TEG® 6s | ROTEM® Delta/Sigma | Quantra® QPlus® QStat® |
ClotPro® | Clinical Significance |
|---|---|---|---|---|---|---|---|
| Clot initiation | Coagulation factors | Reaction time (R), minutes | R | Clotting time (CT), seconds | CT | CT | A short R/CT/CTH time indicates a hypercoagulable state. A prolonged R/CT time indicates either hypocoagulability or the presence of an anticoagulant. A short CTH/CKH in the presence of a long CT /CK-R or CTR > 1.1.indicates the presence of heparin anticoagulation. Specifically, heparin and DOAC tests are available with TEG® 6s, ROTEM® sigma, and ClotPro®. 6 |
| Citrated Kaolin (CK) R-time, minutes | CK-R-time, minutes | INTEM 1 CT | CT | IN-test CT | |||
| rTEG® Activated clotting time (ACT), seconds 1 | Citrated Rapid TEG (CRT) ACT, seconds |
EXTEM 1 CT |
n/a | EX-test CT | |||
| Citrated kaolin-heparinase (CKH) 1 | CKH 1 | HEPTEM 1 CT | Heparinase Clot Time (CTH), seconds | HI-test RVV-test ECA-test NA-test |
|||
| n/a | n/a | n/a | Clot time ratio (CTR) | n/a | |||
| Clot kinetics: amplification | Fibrinogen | Kinetic time (K), minutes | K | Clot formation time (CFT), seconds | Fibrinogen contribution to stiffness (FCS), hPA 2 | CFT | Angle reflects fibrin kinetics, including fibrin formation and cross-linking. FCS measures the direct contribution of stiffness generated by fibrinogen. |
| ɑ angle | ɑ angle | ɑ angle | n/a | ɑ angle | |||
| Citrated functional fibrinogen (MAff/CFF) | MAff/CFF 1 | FIBTEM 1 | n/a | FIB-test 1 | |||
| Clot stiffness: propagation | Fibrinogen, Platelets | CK Maximum amplitude (MA), mm | CK MA, mm | Maximum clot firmness (MCF), mm | Clot stiffness (CS), hPA 2 | MCF | MA, MCF, and CS reflect platelet and fibrinogen contributions to the clot stiffness and full platelet potential under maximal stimulation by thrombin. PCS isolates the platelet contribution to clot stiffness. |
| rTEG® MA, mm | CRT MA, mm | EXTEM 3 MCF | Platelet contribution to clot stiffness (PCS), hPA2 | EX-test MCF 3 | |||
| Clot stability: termination | Fibrinolytic enzymes and inhibitors, Factor XIII | Lysis at 30 min after MA, (LY30), % | LY30 | Clot Lysis Index at 30/60 min after CT (CLI30/CLI60), residual % of MCF 4 Maximum Lysis (ML), % of MCF lysed during run |
Clot Stability to Lysis (CSL), % 5 | Clot Lysis Index at 30/60 min (CLI30/CLI60), % of MCF 4 | Hyperfibrinolysis is suggested by increased clot lysis that starts within 30 min of clot formation. |
| n/a | n/a | APTEM 1 | n/a | AP-test 3 | |||
| n/a | n/a | n/a | n/a | TPA 3 |
1 See Figure 1 and Figure 3 and Table 1 and Table 2 for the definition of the parameters. 2 hPa, hectopascals are units of pressure used to assay clot stiffness in Quantra®. 3 See Section 2.5.3 and Section 2.5.4 in the text and Figure 3 for definitions of the Quantra® and ClotPro® assays and parameters. 4 For the purposes of this review, in ROTEM® sigma/delta and ClotPro®, fibrinolysis is defined uniformly as the clot lysis index (CLI) 5 Measurement of Clot Stability to Lysis (CSL) is only available with the QStat® cartridge. 6 Assays for DOACs (Factor Xa inhibitors and direct thrombin inhibitors) are in various stages of approval for commercial use.