From the Guidelines
Anti-platelet agents affect bleeding time tests and platelet aggregation tests.
Bleeding Tests Affected by Anti-Platelet Agents
- Bleeding time tests: These tests measure the time it takes for bleeding to stop after a small cut is made on the skin. Anti-platelet agents, such as aspirin and P2Y12 inhibitors, can prolong bleeding time by inhibiting platelet activation and aggregation 1.
- Platelet aggregation tests: These tests measure the ability of platelets to clump together and form a blood clot. Anti-platelet agents can inhibit platelet aggregation, making it more difficult for blood to clot 2.
Specific Tests Used to Evaluate Platelet Function
- Platelet function tests: These tests, such as the P2Y12 assay, can be used to evaluate the effectiveness of anti-platelet therapy and to identify patients who may be at risk of bleeding or thrombotic events 2, 3.
Importance of Monitoring Bleeding Risk
It is essential to monitor bleeding risk in patients taking anti-platelet agents, as the risk of bleeding can be increased with these medications. Laboratory tests, such as platelet function tests, can be used to guide therapy and minimize the risk of bleeding 4, 5.
From the Research
Bleeding Tests Affected by Anti-Platelet Agents
- Platelet function assays are used to determine the level of platelet inhibition achieved in a given subject, which can help identify patients at a higher risk of bleeding complications 6, 7
- Point-of-care platelet function tests are available for the peri-procedural assessment of residual platelet aggregation, but these tests are not standardized 8
- Platelet reactivity testing can be used to predict bleeding events after cardiac surgery in patients on antiplatelet therapy 9
- The management of bleeding events associated with antiplatelet therapy relies on poor evidence, and practical guidelines are mainly based on expert opinion 10
Types of Bleeding Tests
- Platelet function tests, such as platelet aggregation tests and platelet activity tests, can be used to assess the pharmacodynamic effects of antiplatelet agents 8, 7
- Platelet reactivity tests, such as those using aspirin and P2Y12 inhibitors, can be used to predict bleeding events after cardiac surgery 9
Limitations of Bleeding Tests
- The efficacy of platelet transfusion to mitigate clinical consequences of bleeding in patients treated with antiplatelet agents depends on various factors, including the type of antiplatelet therapy and the time from the last intake 10
- Specific antidotes for antiplatelet agent neutralisation are needed, especially for ticagrelor, but are not available yet 10
- Little data support the clinical benefit of using platelet function tests for the management of bleeding events in patients treated or potentially treated with antiplatelet agents 10