Basic characteristics and interpretation of commonly used assays to assess platelet function
| Test | Medium | Interpretation | Comments |
|---|---|---|---|
| Light transmission aggregometry | Plasma | Increased light transmission α increased platelet function | Does not account for effect of blood cells on clotting |
| Impedance aggregometry | Whole blood | Increased impedance α increased platelet function | |
| PFA-100 | Whole blood | Decreased closure time α increased platelet function | Not approved for detection of clopidogrel |
| VerifyNow | Whole blood | Akin to light transmission aggregometry | |
| TEG platelet map | Whole blood | Directly reports the percentage of inhibition in maximal platelet function | Variable and high degree of inhibition noted due to illness and injury |
TEG, thrombelastography-platelet mapping.