Clopidogrel Platelet Function Tests
Caveats and Controversies
This slide and the next slide contain the names of platelet function tests which can be used to test for clopidogrel resistance. Clopidogrel acts by irreversibly blocking the ADP receptor P2Y12 on platelets. The first group of tests measures change in direct response to ADP stimulus to determine the effect or lack of effect of clopidogrel on the platelets. The gold standard platelet function test currently is platelet aggregometry, also known as light transmission aggregometry or LTA. Multiplate whole blood aggregometry is a newer variation that can be done without centrifuging the blood and manipulating it to achieve platelet rich plasma. Flow cytometry can test for markers of activation on the platelet surfaces following exposure to ADP. The VerifyNow assay from Accumetrics also detects whole blood platelet aggregation but uses optical detection rather than impedance.
Platelet Function Tests
Jump to section:
- Learning Objectives
- Platelet Function Tests for the Detection of Clopidogrel Resistance1
- Platelet Function Tests for the Detection of Clopidogrel Resistance
- Caveat: There Is No Perfect Platelet Function Test...
- Problems With Testing For Clopidogrel
- How We Choose a Testing Method
- Methodology Table
- Platelet Function Testing Available at Mayo Clinic Florida
- Light Transmission Platelet Aggregometry Studies (LTA)
- Platelet Aggregation (Cont'd)
- Normal Patient
- Accumetrics VerifyNow Test
- VerifyNow P2Y12 Test
- P2Y12 Test Interferences
- P2Y12 Antagonists2
- Can These Platelet Function Tests Be Used for Ticagrelor (Brilinta/Brilique)?
- PFA–100 (Cont'd)
- INNOVANCE PFA P2Y
- TEG — Platelet Mapping
- Results of VerifyNow Testing
- 2009–2011 Clopidogrel Response at 30%
- Genetic Testing: Clopidogrel Metabolism
- Clopidogrel Metabolism
- Number of Gene Polymorphisms
- Clopidogrel Metabolism and Genetic Polymorphisms
- Why Do Genetic Testing?
- Clopidogrel Genetics (Cont'd)
- Caveats — Other Reasons for Poor Response to Clopidogrel
- CYP2C19 Polymorphism May Require Another Factor
- Controversy for Clopidogrel
- Warning: Diminished Effectiveness In Poor Metabolizers
- What Does Warning Mean For Clinicians With Patients On Clopidogrel?
- FDA Answer
- More Questions