A new point-of-care method for monitoring anti-platelet therapy: Application of the cone and plate(let) analyzer

Spectre, Galia; Brill, Alexander; Gural, Alexander; Шенкман, Борис; Touretsky, Natalia; Mosseri, Elinor; Savion, Naphtali; Varon, David

doi:10.1080/09537100400028800

Cited by 33 publications

(17 citation statements)

References 19 publications

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“…In brief, citrated whole blood was placed in a polystyrene well and subjected to flow, and then washed, stained and analysed by an image analysis system, as previously described [12, 13]. Platelet adhesion was assessed as the percentage of total area covered with platelets designated as surface coverage.…”

Section: Methodsmentioning

confidence: 99%

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Aspirin Responsiveness in Acute Brain Ischaemia: Association with Stroke Severity and Clinical Outcome

et al. 2008

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Purpose: Platelets play a critical role in the pathogenesis of acute brain ischaemia. We studied the association between the degree of inhibition of platelet function by aspirin (ASA) and the severity and outcome of acute brain ischaemia. Methods: Platelet responsiveness to ASA was assessed in patients with acute brain ischaemia, treated with ASA since hospital admission. The degree of ASA responsiveness was assessed by optical aggregometry and categorized into patients with good response, partial response and complete unresponsiveness to ASA (good responders, partial responders and non-responders, respectively). An additional evaluation of responsiveness to ASA was performed by Impact-R (cone and platelet analyzer). Patients underwent serial clinical assessment during hospitalization, at discharge and during follow-up. Results: Among 105 patients (mean age 63 ± 12 years; 66% men), impaired ASA responsiveness at baseline as assessed by aggregometry was associated with increased stroke severity at baseline, unfavourable clinical course, and poor functional outcome during follow-up (p < 0.05 for all). Age-adjusted odds ratios in non-responders compared to good responders were 9.8 for severe stroke on admission (95% CI 2.8–34.9), 3.1 for lack of early clinical improvement (95% CI 1.1–8.8) and 8.6 for poor functional outcome during follow-up (95% CI 2.4–30.4). Less robust trends were observed with the Impact-R. Conclusions: Impaired responsiveness to ASA in acute brain ischaemia is common and is associated with worse neurological deficits at stroke onset, early clinical deterioration and poorer functional outcome. The clinical significance of these findings requires further evaluation in larger longitudinal studies.

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Section: Methodsmentioning

confidence: 99%

“…In addition, ASA responsiveness was evaluated by the Impact-R (cone and platelet analyzer), measuring whole blood platelet adhesion under flow conditions following AA pretreatment [11, 12]. …”

Section: Methodsmentioning

confidence: 99%

Aspirin Responsiveness in Acute Brain Ischaemia: Association with Stroke Severity and Clinical Outcome

et al. 2008

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“…Based on the demonstrated in vitro effect of aspirin and 2MeSAMP, preliminary studies have been conducted to determine the degree of the effect of aspirin and clopidogrel by the Impact-R AA-and ADP-response tests [17][18][19]. Increased SC in the agonist-response test in a blood sample of a patient treated with the corresponding drug, showed a good response to the drug.…”

Section: Discussionmentioning

confidence: 99%

“…This phenomenon has already been used to adapt the CPA technology in testing the platelet response to aspirin and clopidogrel treatment [17][18][19]. In the present study, the technology was extended to assess platelet aggregation in response to suboptimal concentrations of various agonists.…”

Section: Introductionmentioning

confidence: 97%

Testing agonist-induced platelet aggregation by the Impact-R [Cone and plate(let) analyzer (CPA)]

Шенкман¹,

Einav²,

Salomon³

et al. 2008

Platelets

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The Impact-R [Cone and plate(let) analyzer (CPA)] is useful to assess platelet adhesion in different diseases and to monitor antiplatelet therapy. The purpose of the present study was to adapt this system to test agonist-induced platelet aggregation. Blood samples were tested by light transmission platelet aggregometry (LTA), Impact-R regular test and Impact-R agonist-response test. In the latter, samples were pre-incubated for 1 min with an agonist leading to platelet activation, micro-aggregates formation and reduced adhesion. Impact-R regular test of ten healthy volunteers demonstrated platelet adhesion (surface coverage, SC) of 11.2 +/- 2.6% while LTA induced by ADP, ristocetin, epinephrine, collagen and arachidonic acid (AA) yielded maximal aggregation (81% to 93%). In the Impact-R agonist-response test, SC was reduced to 2.2 +/- 1.0%, 1.2 +/- 0.9%, 2.3 +/- 1.0%, 2.2 +/- 0.8% and 2.4 +/- 0.4%, respectively. Prostaglandin E(1) treatment weakened SC reduction in response to ADP and epinephrine (SC of 8.8 +/- 1.8% and 9.5 +/- 2.0%, respectively). Inhibition of P2Y(12) receptor with 2MeSAMP resulted in a dose-dependent decrease in maximal aggregation in the ADP-induced test, which inversely correlated to SC in the Impact-R ADP-response test. The Impact-R agonist-response tests detected aggregation defects in patients with storage pool disease, severe von Willebrand disease and epinephrine response deficiency, and may be useful to assess the effect of different agonists on platelet aggregation.

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“…The second point-of-care platelet function assay that has been demonstrated to correlate with clinical events is the Cone-and-Platelet Analyzer, a shear-induced platelet function analyzer [62][63][64][65]. Samples of whole blood (200 µl) are placed into polystyrene well plates, and subjected to a shear rate of 1800s -1 for 2 min using a specially developed Teflon cone.…”

Section: Camentioning

confidence: 99%

Clopidogrel Resistance: Fact and Fiction

et al. 2006

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The antiplatelet agent clopidogrel in combination with aspirin has been shown to reduce thrombotic events in patients with acute coronary syndromes and/or who are undergoing percutaneous coronary intervention. However, a large interindividual response variability to clopidogrel has been described. The reported rates of inadequate clopidogrel response vary considerably depending on the definition and methodologies used to measure the inhibition of platelet function. Recently, several (small) studies have demonstrated the clinical relevance of an inadequate response to clopidogrel. Moreover, several factors have been associated with a high interindividual variability in response to clopidogrel. These are: dosing, impaired intestinal absorption, cytochrome P450 3A4 and 3A5 activity, drug-drug interactions, polymorphisms of the receptors involved in the process of arterial thrombosis and hemostasis, and the method of measurement of platelet function. Future research for the evaluation of clopidogrel resistance should be based on the assessment of selective P2Y12 receptor inhibition (e.g., the vasodilator-stimulated phosphoprotein-assay or the measurement of stabilization of platelet aggregates) with quick and simple tests. Only then can we reveal the true prevalence and impact of clopidogrel resistance.

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A new point-of-care method for monitoring anti-platelet therapy: Application of the cone and plate(let) analyzer

Cited by 33 publications

References 19 publications

Aspirin Responsiveness in Acute Brain Ischaemia: Association with Stroke Severity and Clinical Outcome

Aspirin Responsiveness in Acute Brain Ischaemia: Association with Stroke Severity and Clinical Outcome

Testing agonist-induced platelet aggregation by the Impact-R [Cone and plate(let) analyzer (CPA)]

Clopidogrel Resistance: Fact and Fiction

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