Platelet Function Testing in Patients on Antiplatelet Medications

Abstract

Guidelines provide a Class IA recommendation for the use of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention (PCI). However, there is interindividual variability in the pharmacodynamic response to antiplatelet medications. Some patients present with a status of high on-treatment platelet reactivity (HPR) during platelet function testing after standard doses of antiplatelet drugs, reflecting a failure to achieve adequate platelet inhibition. As an example, patients with HPR on clopidogrel are at increased risk for thrombotic events, particularly for stent thrombosis and myocardial infarction, but cardiovascular mortality is also elevated. On the contrary, low on-treatment platelet reactivity or an enhanced response to antiplatelet medications has been linked to a higher risk for bleeding. Although both thrombotic and bleeding events are multifactorial in origin, there is supportive evidence for the prognostic value of platelet function testing for risk prediction of both sides of the coin. However, although small studies have provided evidence that treatment adjustments based on platelet function testing results may improve clinical outcomes, the available randomized controlled trials showed no benefit of modifying antiplatelet treatment based on platelet function testing. This review presents the current evidence regarding platelet function testing in patients undergoing PCI. The prognostic value of platelet function testing regarding ischemic and bleeding events is highlighted. Furthermore, the value of platelet function testing for guiding treatment and possible explanations for the so-far negative trial results are presented. The possible future role of platelet function testing for individualized antiplatelet treatment regimens in high-risk patients will be also discussed.

Si-Miao-Yong-An Decoction Protects Against Cardiac Hypertrophy and Dysfunction by Inhibiting Platelet Aggregation and Activation

“…The metabolism of clopidogrel into its active metabolites is affected by individual polymorphisms of CYP enzymes (Jarrar et al, 2016). Patients with high on-treatment platelet reactivity upon clopidogrel were at increased risk for thrombotic events, particularly for stent thrombosis and myocardial infarction, but cardiovascular mortality was also elevated in patients undergoing percutaneous coronary intervention (Gross et al, 2016). It was reported that aspirin use after discharge for HF hospitalization was associated with reduced risk of death, all-cause readmission, and HF readmission (Kim et al, 2016).…”

MicroRNA as Potential Biomarkers of Platelet Function on Antiplatelet Therapy: A Review

“…There are various approaches for platelet function assessment, and most of them focus on the measurements carried out after platelet activation caused by agonist administration (Koltai et al, 2017;Ostrowska et al, 2019). Despite the wide range of available tests, some are discussed below, new, more sensitive and specific biomarkers are needed, especially for the monitoring of antiplatelet therapy (Gross et al, 2016). It has been revealed in some research that sP-selectin or CD40L might serve as such biomarkers, but their detectability time in general circulation is short (Yun et al, 2016).…”

P2Y12 inhibitors in neuroendovascular surgery: An opportunity for precision medicine

“…Current cardiology guidelines define LPR, optimal PR (OPR), and HPR categories as <95, 95-208, and >208 PRU for VerifyNow testing. 32 Similar to aspirin treatment, 33 the presence of risk factors seems a significant contributor to the clinical relevance of HPR and outcome. 34 A meta-analysis of 6,000 individual on-clopidogrel patient data 35 showed that HPR was prognostic for MACE in a dose-dependent fashion.…”