Clinical significance of residual platelet reactivity in patients treated with platelet P2Y12 inhibitors.
Platelet P2Y12 inhibitors have become an essential component of the treatment strategy for patients with acute coronary syndromes and patients undergoing percutaneous coronary intervention. It is now well-established that approximately 30% of patients treated with the P2Y12 inhibitor clopidogrel display high residual platelet reactivity despite treatment. Patients with high on-treatment platelet reactivity have approximately 2-3-fold greater risk of adverse cardiovascular events and stent thrombosis than those without high platelet reactivity. Conversely, clopidogrel-treated patients with low platelet reactivity display approximately 1.7-fold increased risk of major bleeding. High platelet reactivity is uncommon during treatment with prasugrel and ticagrelor, which achieve a greater reduction in adverse cardiovascular events compared to clopidogrel in ACS patients treated with PCI. This is at the expense of an increase in spontaneous bleeding, however. Minor bleeding events, such as skin haematomas, are more common in prasugrel- and ticagrelor-treated patients that have particularly low platelet reactivity values. These minor bleeding events may occasionally prompt discontinuation of therapy, but their overall prognostic impact is uncertain. However, risk factors for bleeding tend to overlap with risk factors for adverse cardiovascular events. Therefore, patients with these minor bleeding events may also be at higher risk of adverse cardiovascular events, conferring a benefit from low platelet reactivity. Further work is needed to determine the optimal level of platelet reactivity in individuals by taking into account their risk of subsequent adverse cardiovascular events and bleeding.
Cardiovascular Research Unit, University of Sheffield, United Kingdom. Electronic address: markthomas@doctors.org.uk.
Mark R
MR
Thomas
Cardiovascular Research Unit, University of Sheffield, United Kingdom.
Robert F
RF
Storey
D054058:Acute Coronary Syndrome / Q000188:drug therapy; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D062645:Percutaneous Coronary Intervention / Q000379:methods; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000494:pharmacology*; D058921:Purinergic P2Y Receptor Antagonists / Q000009:adverse effects / Q000494:pharmacology*; D012307:Risk Factors
D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists
Bleeding; Clopidogrel; Ischaemic events; Prasugrel; Ticagrelor