In TEG, CFT stands for Clot Formation Time.
In the context of Thromboelastography (TEG), CFT specifically refers to Clot Formation Time. This parameter provides crucial insight into the kinetics of clot strengthening after the initial formation has occurred.
According to the provided reference, CFT is precisely defined as:
"the time necessary for clot amplitude to increase from 2 to 20 mm."
Alongside parameters like Kinetics Time (K) and Angle (α), CFT helps characterize the speed and efficiency of clot development once the initial clot is detected (at the point defined by CT or R time).
Understanding CFT within TEG
Thromboelastography (TEG) is a test used to assess the viscoelastic properties of whole blood clot formation. It provides a graphical representation of the entire clotting process, from initial platelet-fibrin interaction to clot lysis. Various parameters are measured from this graph to evaluate different aspects of coagulation.
Key parameters typically measured in TEG include:
- R-time (or CT - Clotting Time): The time from sample placement until the first significant clot formation (typically 2 mm amplitude). This reflects the initiation phase and primarily depends on coagulation factors.
- K-time (or CFT - Clot Formation Time): As defined in the reference, the time taken for the clot amplitude to increase from 2 mm to 20 mm. This represents the speed of clot strengthening.
- Alpha (α) Angle: The angle of the tangent line drawn from the R time point to the curve. This also reflects the kinetics of clot formation and correlates with K-time and fibrinogen function.
- MA (Maximum Amplitude): The maximum strength or stiffness of the clot, reflecting the overall contribution of platelets and fibrinogen to clot structure.
- LY30 (Lysis at 30 minutes): Percentage of clot lysis 30 minutes after MA is reached, indicating fibrinolysis.
Clinical Significance of CFT
CFT is a measure of the clot's ability to strengthen rapidly. A normal CFT range indicates effective interaction between platelets and fibrinogen in building the clot's structure.
- Prolonged CFT: Can suggest issues with clot kinetics, often related to:
- Defects in fibrinogen function or concentration.
- Platelet function disorders.
- Presence of certain medications affecting platelet function or fibrin formation.
- Shortened CFT: Less common, but might suggest hypercoagulability depending on the context and other parameters.
Understanding CFT, along with other TEG parameters, helps clinicians assess a patient's coagulation status and guide transfusion or antithrombotic therapy. While the reference specifically defines CFT (Clot Formation Time), it's worth noting that some TEG systems may use 'K' (Kinetics Time) to represent the time to reach a specific amplitude (e.g., 20mm), effectively serving a similar function to what the reference describes for CFT and K interchangeably as reaching 20mm from 2mm. However, adhering strictly to the reference, CFT is the term used for this specific time measurement.
