Platelet Reactivity in Patients and Recurrent Events Post-Stenting

Abstract

High platelet reactivity and clot strength, and rapid fibrin formation are novel risk factors for ischemic events after PCI. Clot strength is more predictive than ADP-induced platelet aggregation and may explain the occurrence of events despite treatment with cyclooxygenase-1 and P2Y12 inhibitors.

Usefulness of thrombelastography platelet mapping assay to measure the antiplatelet effect of P2Y12receptor inhibitors and high on-treatment platelet reactivity

“…Supported by the technical advance, the response to antiplatelet therapy can be evaluated by TEG with the setting of platelet mapping assay. In addition, we reported that MA ADP [adenosine diphosphate (ADP)-induced platelet-fibrin clot strength]447 mm was significantly associated with the short-and long-term post-PCI clinical outcomes, and could be used as an important predictor of ischemic events occurrence [3,4]. Although TEG might be more reflective of the physiologic character of a blood clot in vivo, its correlation with currently widely used platelet function testing has not been validated.…”

High-residual platelet activity despite dual antiplatelet treatment associated with subacute stent thrombosis

“…In recent LTA studies, for stent thrombosis ≥40%, and for ischemic events within 6 months ≥50% of inducible platelet aggregation after stimulation by 20 µl/l ADP, is considered a relevant value [4,8]. It is thus necessary to achieve more than 50% inhibition of aggregation to optimize the clinical outcome after coronary stenting.…”

“…After ARA inductor, the inhibition of platelet aggregation reached only 58% (residual aggregation 42%), and after ADP inductor, only 33% (residual aggregation 67%) ( Figure 2). The cutoff point for effective treatment with aspirin was considered in reaching at least 80% inhibition [3], and for clopidogrel treatment at least 50% [4]. According to these results, we have decided to increase the dose of oral aspirin to 400 mg daily, and to displace treatment with clopidogrel by ticlopidin in a daily dose of 500 mg. After 5 days of treatment with an increased dose of aspirin and 500 mg of ticlopidin, the LTA was repeated.…”

Impact of CYP2C19 Polymorphism on Platelet Function Tests and Coagulation and Inflammatory Biomarkers in Patients Undergoing Percutaneous Coronary Intervention

“…Based on the clinical outcomes of patients with ACS undergoing PCI, recent studies have advocated the use of careful monitoring of the on-clopidogrel PA level using various platelet function assays 15,16) . In a previous study, we also demonstrated the efficacy of on-clopidogrel PA monitoring by showing the cutoff level of on-clopidogrel PA that can be used to discriminate carriers of the functional CYP2C19 reducedfunction allele among patients with stable coronary artery disease (CAD) treated with clopidogrel 17) .…”

“…LTA is considered to be a standard test that includes measurements of the on-clopidogrel PA levels in CAD patients receiving dual antiplatelet therapy 11,15,38) . However, LTA has certain drawbacks in measuring platelet aggregation, such as the long sample processing time and need for expert personnel.…”