Identification of poor response to P2Y12 inhibitors in ACS patients with a new ELISA-based vasodilator-associated stimulated phosphoprotein (VASP) phosphorylation assay

2013 ◽  
Vol 110 (11) ◽  
pp. 1055-1064 ◽  
Author(s):  
Jérémie Abtan ◽  
Johanne Silvain ◽  
Mathieu Kerneis ◽  
Stephen A. O’Connor ◽  
Olivier Barthélémy ◽  
...  
Keyword(s):  
Light Transmission ◽  
Platelet Reactivity ◽  
Poor Response ◽  
Threshold Value ◽  
Reactivity Index ◽  
Operating Characteristics ◽  
Specific Test ◽  
P2y12 Inhibitors ◽  
Coronary Syndrome ◽  
Vasp Phosphorylation

SummaryA new ELISA technique has been developed to measure the vasodilator-associated stimulated phosphoprotein (VASP) platelet reactivity index (PRI) in clopidogrel-treated patients. This technique has not been evaluated in acute coronary syndrome (ACS) patients or in prasugrel-treated patients. We assessed the accuracy of ELISA-VASP to identify high on-treatment platelet reactivity (HPR) in ACS patients in comparison with established platelet function tests. Platelet reactivity was measured in 240 ACS patients treated with clopidogrel (75 or 150 mg) or prasugrel (5 or 10 mg) using flow cytometry (FC-VASP) and the ELISA-VASP technique, light transmission aggregometry (LTA) and VerifyNow-P2Y12 assay (VN-P2Y12). When using the ELISA-VASP PRI, the rate of patients with HPR in the overall ACS population was 15.5%, including a 27% rate in clopidogrel-treated patients and a 4% rate in prasugrel-treated patients. There was a strong correlation between ELISA-VASP PRI and FC-VASP PRI (r = 0.83, r2 = 0.68 p < 0.0001) with an area under the receiver-operating characteristics (ROC) curve to identify HPR (VASP-PRI >50% with FC-VASP) of 0.94, p<0.0001. The threshold of 60% for ELISA-VASP PRI provided the best accuracy (likelihood ratio= 23.67) to identify patients with HPR when compared to FC-VASP, LTA or VN-P2Y12 assays. In conclusion, ELISA-VASP is a fast, easy-to-use and specific test to identify HPR in ACS patients on thienopyridines. A 60% threshold value displays the best accuracy to identify HPR in these patients.

scholarly journals Sensitivity of Viscoelastic Tests to Platelet Function

2020 ◽  
Vol 9 (1) ◽  
pp. 189 ◽  
Author(s):  
Marco Ranucci ◽  
Ekaterina Baryshnikova
Keyword(s):  
Platelet Function ◽  
Light Transmission ◽  
Platelet Reactivity ◽  
Point Of Care ◽  
Dynamic Assessment ◽  
Antiplatelet Agents ◽  
Protease Activated Receptors ◽  
Specific Test ◽  
Clot Strength ◽  
P2y12 Inhibitors

Viscoelastic tests provide a dynamic assessment of coagulation, by exploring the time to clot formation and the clot strength. Using specific activators or inhibitors, additional factors can be explored, like the fibrinogen contribution to clot strength. Since the early days, various attempts have been done to measure platelet function with viscoelastic test. In general, the difference between the maximum clot strength and the fibrinogen contribution is considered an index of platelet contribution. However, this parameter does not clearly split platelet count from function; additionally, the extensive thrombin generation of standard activated viscoelastic tests activates platelet through the protease activated receptors, bypassing the other pathways. For this reason, standard viscoelastic tests cannot be used to assess platelet reactivity under the effects of aspirin or P2Y12 inhibitors. To overcome this limitation, a specific test was developed (thromboelastography platelet mapping). This test has been compared with the gold standard of light transmission aggregometry and with other point-of-care tests, with conflicting results. In general, the use of viscoelastic tests to assess the effects of antiplatelet agents is still limited. Conversely, platelet contribution to clot strength in the setting of coagulopathic bleeding is considered an important parameter to trigger platelet transfusion or desmopressin.

A comparison of the antiplatelet effects of prasugrel and high-dose clopidogrel as assessed by VASP-phosphorylation and light transmission aggregometry

2008 ◽  
Vol 99 (01) ◽  
pp. 215-222 ◽  
Author(s):  
Christopher D Payne ◽  
Ying G Li ◽  
Nagy A Farid ◽  
John T Brandt ◽  
David S Small ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Light Transmission ◽  
Platelet Reactivity ◽  
Platelet Inhibition ◽  
P2y12 Receptor ◽  
Reactivity Index ◽  
High Dose ◽  
Receptor Blockade ◽  
Vasp Phosphorylation ◽  
Light Transmission Aggregometry

SummaryPlatelet inhibition as measured by vasodilator-stimulated phosphoprotein (VASP) and light transmission aggregometry (LTA) have shown concordance following dosing of clopidogrel. No reports have directly compared theVASP assay and LTA at the levels of P2Y12 blockade after loading doses (LDs) of prasugrel or high dose clopidogrel (600 and 900 mg).The aim was to compare theVASP assay and LTA during the loading dose phase of a comparative study of prasugrel and clopidogrel. Prasugrel 60 mg LD/10 mg maintenance dose (MD) and clopidogrel 300 mg/75 mg and 600 mg/75 mg LD/MD regimens were compared in a 3-way crossover study in 41 healthy, aspirin-free subjects. Each LD was followed by seven daily MDs and a 14-day washout period. P2Y12 receptor blockade was estimated using theVASP assay, expressed as platelet reactivity index (VASP-PRI). Platelet aggregation was assessed by light transmission aggregometry (20 and 5 μM ADP).Twenty-four hoursafter prasgurel 60 mg or clopidogrel 300 mg and 600 mg, respectively, VASP-PRI decreased from ∼80% to 8.9%, 54.7%, and 39.0 %, and maximal platelet aggregation (MPA) decreased from ∼79% to 10.8%, 42.7%, and 31.2%, with an overall VASP:MPA correlation of 0.88 (p<0.01). VASP assay responses after the clopidogrel LDs showed a wider range of values (300 mg: 0–93%; 600 mg: 0–80%) than prasugrel (0–13%); MPA responses followed a similar trend. Pearson’s correlation suggested a strong agreement between VASP and LTA (20 μM ADP) for MPA (r=0.86, p<0.0001).VASP and LTA demonstrated concordance across the response range of P2Y12 receptor blockade following thienopyridine LDs.

scholarly journals Comparison of Light Transmission Aggregometry With Impedance Aggregometry in Patients on Potent P2Y12 Inhibitors

2020 ◽  
pp. 107424842096870
Author(s):  
Patricia P. Wadowski ◽  
Joseph Pultar ◽  
Constantin Weikert ◽  
Beate Eichelberger ◽  
Irene M. Lang ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Light Transmission ◽  
Platelet Reactivity ◽  
Adenosine Diphosphate ◽  
P2y12 Inhibitors ◽  
Coronary Syndrome ◽  
Multiple Electrode Aggregometry ◽  
Impedance Aggregometry ◽  
Light Transmission Aggregometry ◽  
Sensitivity Specificity

Since data on the agreement between light transmission aggregometry (LTA) and multiple electrode aggregometry (MEA) in patients on the more potent P2Y12 inhibitors are missing so far, we investigated if the evaluation of the responsiveness to therapy by LTA can be replaced by MEA in 160 acute coronary syndrome (ACS) patients on dual antiplatelet therapy with aspirin and prasugrel or ticagrelor (n = 80 each). Cut-off values for high on-treatment residual platelet reactivity (HRPR) in response to adenosine diphosphate (ADP) or arachidonic acid (AA) were defined according to previous studies showing an association of HRPR with the occurrence of adverse ischemic outcomes. ADP- inducible platelet aggregation was 33% and 37% (p = 0.07) by LTA and 19 AU and 20 AU (p = 0.38) by MEA in prasugrel- and ticagrelor-treated patients, respectively. AA- inducible platelet aggregation was 2% and 3% by LTA and 15 AU and 16 AU by MEA, (all p ≥ 0.3) in patients on prasugrel and ticagrelor, respectively. By LTA, HRPR ADP and HRPR AA were seen in 5%/5% and in 4%/ 13% of patients receiving prasugrel- and ticagrelor, respectively. By MEA, HRPR ADP and HRPR AA were seen in 3%/ 25% and 0%/24% of prasugrel- and ticagrelor-treated patients, respectively. ADP-inducible platelet reactivity by MEA correlated significantly with LTA ADP in prasugrel-treated patients (r = 0.4, p < 0.001), but not in those receiving ticagrelor (r = 0.09, p = 0.45). AA-inducible platelet aggregation by LTA and MEA did not correlate in prasugrel- and ticagrelor-treated patients. Sensitivity/specificity of HRPR by MEA to detect HRPR by LTA were 25%/99% for MEA ADP and 100%/79% for MEA AA in prasugrel-treated patients, and 0%/100% for MEA ADP and 70%/83% for MEA AA in ticagrelor-treated patients. In conclusion, on-treatment residual ADP-inducible platelet reactivity by LTA and MEA shows a significant correlation in prasugrel- but not ticagrelor-treated patients. However, in both groups LTA and MEA revealed heterogeneous results regarding the classification of patients as responders or non-responders to P2Y12 inhibition.

Clopidogrel pretreatment in primary percutaneous coronary intervention: Prevalence of high on-treatment platelet reactivity and impact on preprocedural patency of the infarct-related artery

2013 ◽  
Vol 110 (07) ◽  
pp. 110-117 ◽  
Author(s):  
Javier Berdejo ◽  
Gerard Roura ◽  
Josep Gómez-Lara ◽  
Rafael Romaguera ◽  
Luis Teruel ◽  
...  
Keyword(s):  
Percutaneous Coronary Intervention ◽  
Primary Percutaneous Coronary Intervention ◽  
Light Transmission ◽  
Platelet Reactivity ◽  
Poor Response ◽  
Antiplatelet Agents ◽  
Coronary Intervention ◽  
Platelet Inhibition ◽  
Percutaneous Coronary ◽  
Infarct Related Artery

SummaryTo date, there is limited data on levels of platelet inhibition achieved in patients with ST-elevation myocardial infarction (STEMI) who are loaded with clopidogrel and aspirin (ASA) prior to undergoing primary percutaneous coronary intervention (P-PCI). The aim of this investigation was to evaluate the percentage of STEMI patients with high on-treatment platelet reactivity (HPR) to clopidogrel at the time of initiating P-PCI and its association with the initial patency of the infarct-related artery (IRA). This prospective pharmacodynamic study included 50 STEMI patients, previously naïve to oral antiplatelet agents, who received 500-mg ASA and 600-mg clopidogrel loading doses prior to P-PCI. Platelet function assessment was performed at the beginning of the procedure using various assays, including VerifyNow™ system (primary endpoint), light transmission aggregometry and multiple electrode aggregometry. The percentage of patients with suboptimal response to clopidogrel and ASA assessed with the VerifyNow™ system was 88.0% and 28.6%, respectively. Similar results were obtained with the other assays used. A higher percentage of patients with initial patency of the IRA was observed among those patients without HPR compared with those with HPR to clopidogrel (66.7% vs 15.9%; p=0.013), while no differences were observed regarding postprocedural angiographic or electrocardiographic outcomes. In conclusion, this study shows that a high percentage of STEMI patients have inadequate levels of clopidogrel-induced and, to a lesser extent, aspirin-mediated platelet inhibition when starting a P-PCI procedure, and suggests that a poor response to clopidogrel might be associated with impaired initial TIMI flow in the IRA.

Comparison of VASP-phosphorylation assay to light-transmission aggregometry in assessing inhibition of the platelet ADP P2Y12 receptor

2006 ◽  
Vol 96 (12) ◽  
pp. 767-773 ◽  
Author(s):  
Agnieszka Pampuch ◽  
Giovanni de Gaetano ◽  
Chiara Cerletti
Keyword(s):  
Light Transmission ◽  
Platelet Reactivity ◽  
Flow Cytometric Analysis ◽  
Individual Variability ◽  
P2y12 Receptor ◽  
Reactivity Index ◽  
Drug Induced ◽  
Light Transmission Aggregometry ◽  
Adp Receptor

SummaryThere is need to improve platelet function testing to monitor the response to antiplatelet drugs. We compared flow-cytometric analysis of intraplatelet vasodilator-stimulated phosphoprotein phosphorylation (VASP-P) to light-transmission aggregometry for the detection of drug-induced in-vitro inhibition of the platelet P2Y12 ADP receptor on 22 healthy subjects (10 males, 12 females, 28.5 ± 6.6 years). The platelet reactivity index (PRI) of VASP was calculated both from mean fluorescence intensity (MFI) and percent of fluorescence-positive platelets in the presence of PGE1 with or without ADP (10 µM). Platelet aggregation was induced by ADP (1.25, 2.5 and 5 µM). Cangrelor, a competitive inhibitor of the P2Y12 receptor, preincubated 5 minutes, induced a concentration-dependent inhibition of platelet ADP-receptor function in both tests. Indeed PRI (%) based on either MFI or percent platelets gated were highly correlated with each other (r = 0.97, p<0.0001) and with aggregation in- duced by ADP. The IC50 of cangrelor against each of the three ADP concentrations used in aggregometry increased from 5.8 ± 3.4 nM to 23.1 ± 4.0 nM and to 98 ± 25 nM, respectively. The IC50 of cangrelor based on VASP-P was within the same range (25.5 ± 7.7 nM). No correlation was observed between IC50 values of cangrelor and ADP concentrations giving 50% effect (EC50) in the absence of the drug. However, at 10 nM cangrelor seven subjects could be identified by the VASP-P assay as “low responders” to the drug (PRI> 50%), and six of them also had an aggregation response to 5 µM ADP > 50%. These six subjects showed the lowest ADP EC50 values in the absence of the drug, possibly reflecting high sensitivity of their platelet P2Y12 receptors to ADP. In conclusion, both the VASP-P assay and light-transmission aggregometry detect in a comparable way in-vitro pharmacological inhibition of the platelet P2Y12 ADP receptor and its individual variability.

Early determination of clopidogrel responsiveness by platelet reactivity index identifies patients at risk for cardiovascular events after myocardial infarction

2011 ◽  
Vol 106 (07) ◽  
pp. 141-148 ◽  
Author(s):  
Andreas Schäfer ◽  
Ulrike Flierl ◽  
Jürgen Kössler ◽  
Nora Seydelmann ◽  
Anna Kobsar ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Platelet Reactivity ◽  
Density Lipoprotein ◽  
Coronary Intervention ◽  
Platelet Inhibition ◽  
Systematic Evaluation ◽  
Reactivity Index ◽  
Operating Characteristics ◽  
Patients At Risk ◽  
Acute Mi

SummaryWhile acute myocardial infarction (MI) is associated with impaired clopidogrel responsiveness, systematic evaluation is lacking due to the inability of functional aggregation-based assays to analyse clopidogrel responsiveness in the presence of glycoprotein IIb/IIIa inhibitors. Using the P2Y12-specific, non-aggregation-based platelet-reactivity-index (PRI) we assessed clopidogrel responsiveness in patients with acute MI. Clopidogrel responsiveness was determined 24 hours (h) after loading with 600 mg clopidogrel in 54 patients with acute MI admitted for coronary intervention. A PRI > 50% was considered as suboptimal inhibition. Overall response in MI patients was suboptimal with a median PRI of 58%. Diabetes, low high-density lipoprotein and pre-hospital clopidogrel loading were associated with impaired clopidogrel responsiveness. Patients loaded at first medical contact had a significantly weaker platelet inhibition by clopidogrel after 24 h (PRI 63%) compared to those loaded peri-interventionally (PRI 54%, p=0.014). Clinical outcome was assessed as a combination of cardiac death, non-fatal MI, stent thrombosis, ischaemic stroke, and urgent target vessel revascularisation after 12 months. The pre-selected cut-off of PRI ≤ 50% yielded a sensitivity of 87% at a specificity of 26%, whereas a PRI ≤ 57% determined by receiver-operating characteristics (ROC)-analysis yielded a sensitivity of 80% at a specificity of 56% (event rate: PRI ≤ 57%: 12.0%; PRI > 57%: 41.4%, p=0.0136). In conclusion, PRI detects clopidogrel responsiveness in acute MI patients requiring glycoprotein IIb/IIIa antagonism; and impaired clopidogrel responsiveness predisposes to clinical events. Pre-hospital clopidogrel loading was associated with impaired response and more adverse events challenging the concept of earliest oral clopidogrel loading in MI patients.

scholarly journals Comparison of platelet reactivity between prasugrel and ticagrelor in patients with acute coronary syndrome: a meta-analysis

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Mingxiang Wen ◽  
Yaqi Li ◽  
Xiang Qu ◽  
Yanyan Zhu ◽  
Lingfang Tian ◽  
...  
Keyword(s):  
Acute Coronary Syndrome ◽  
Platelet Reactivity ◽  
Weighted Mean Difference ◽  
Meta Analysis ◽  
Reactivity Index ◽  
Cochrane Library ◽  
Coronary Syndrome ◽  
Significant Difference ◽  
Definition Of ◽  
The Cochrane Library

Abstract Background This meta-analysis aimed to compare the effects of prasugrel and ticagrelor on high (HTPR) and low on-treatment platelet reactivity (LTPR) in patients with acute coronary syndrome (ACS). Methods Eligible studies were retrieved from PubMed, Embase, and the Cochrane Library. HTPR and LTPR were evaluated on the basis of the vasodilator-stimulated phosphoprotein platelet reactivity index (VASP-PRI) and P2Y12 reaction units (PRUs). HTPR and LTPR were analyzed using risk ratios (RRs) and their 95% confidence intervals (CIs). Weighted mean difference (WMD) and 95% CI were used to calculate the pooled effect size of platelet reactivity (PR). Results Fourteen eligible studies were obtained, which included 2629 patients treated with ticagrelor (n = 1340) and prasugrel (n = 1289). The pooled results showed that the prasugrel-treated patients had higher platelet reactivity than the ticagrelor-treated patients (PRU: WMD = − 32.26; 95% CI: − 56.48 to − 8.76; P < 0.01; VASP-PRI: WMD = − 9.61; 95% CI: − 14.63 to − 4.60; P = 0.002). No significant difference in HTPR based on PRU was identified between the ticagrelor and prasugrel groups (P = 0.71), whereas a lower HTPR based on VASP-PRI was found in the ticagrelor-treated patients than in the prasugrel-treated patients (RR = 0.30; 95% CI: 0.12–0.75; P = 0.010). In addition, the results showed a lower LTPR was observed in the prasugrel group than in the ticagrelor group (RR = 1.40; 95% CI: 1.08–1.81; P = 0.01). Conclusions Prasugrel might enable higher platelet reactivity than ticagrelor. Ticagrelor could lead to a decrease in HTPR and increase in LTPR. However, this result was only obtained in pooled observational studies. Several uncertainties such as the nondeterminancy of the effectiveness of ticagrelor estimated using VASP-PRI or the definition of HTPR (a high or modifiable risk factor) might have affected our results.

Enhanced active metabolite generation and platelet inhibition with prasugrel compared to clopidogrel regardless of genotype in thienopyridine metabolic pathways

2013 ◽  
Vol 110 (12) ◽  
pp. 1223-1231 ◽  
Author(s):  
Dominick J. Angiolillo ◽  
Jose L. Ferreiro ◽  
Joseph A. Jakubowski ◽  
Kenneth J. Winters ◽  
Mark B. Effron ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Active Metabolite ◽  
Platelet Reactivity ◽  
Coronary Intervention ◽  
Platelet Inhibition ◽  
Reactivity Index ◽  
Coronary Syndrome ◽  
Metabolite Generation ◽  
Artery Disease ◽  
The Impact

SummaryClopidogrel response varies according to the presence of genetic polymorphisms. The CYP2C19*2 allele has been associated with impaired response; conflicting results have been reported for CYP2C19*17, ABCB1, and PON1 genotypes. We assessed the impact of CYP2C19, PON1, and ABCB1 polymorphisms on clopidogrel and prasugrel pharmacodynamic (PD) and pharmacokinetic (PK) parameters. Aspirin-treated patients (N=194) with coronary artery disease from two independent, prospective, randomised, multi-centre studies comparing clopidogrel (75 mg) and prasugrel (10 mg) were genotyped and classified by predicted CYP2C19 metaboliser phenotype (ultra metabolisers [UM] = *17 carriers; extensive metabolisers [EM] = *1/1 homozygotes; reduced metabolisers [RM] = *2 carriers). ABCB1 T/T and C/T polymorphisms and PON1 A/A, A/G and G/G polymorphisms were also genotyped. PD parameters were assessed using VerifyNow® P2Y12 and vasodilator stimulated phosphoprotein (VASP) expressed as platelet reactivity index (PRI) after 14 days of maintenance dosing. Clopidogrel and prasugrel active metabolite (AM) exposure was calculated in a cohort of 96 patients. For clopidogrel, genetic variants in CYP2C19, but not ABCB1 or PON1, affected PK and PD. For prasugrel, none of the measured genetic variants affected PK or PD. Compared with clopidogrel, platelet inhibition with prasugrel was greater even in the CYP2C19 UM phenotype. Prasugrel generated more AM and achieved greater platelet inhibition than clopidogrel irrespective of CYP2C19, ABCB1, and PON1 polymorphisms. The lack of effect from genetic variants on prasugrel AM generation or antiplatelet activity is consistent with previous studies in healthy volunteers and is consistent with improved efficacy in acute coronary syndrome patients managed with percutaneous coronary intervention.

scholarly journals Impact of smoking habit on platelet reactivity in a cohort of patients admitted due to an acute coronary syndrome

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J.C Gomez Polo ◽  
D Vivas Balcones ◽  
A.L Marcano Fernandez ◽  
J Playan Escribano ◽  
L.M Lugo Gavidia ◽  
...  
Keyword(s):  
Acute Coronary Syndrome ◽  
Platelet Function ◽  
Platelet Reactivity ◽  
Smoking Habit ◽  
Tertiary Care ◽  
Funding Source ◽  
P2y12 Inhibitors ◽  
Lower Response ◽  
Coronary Syndrome ◽  
The Impact

Abstract Background Several pharmacodynamic studies have shown the impact of smoking habit on platelet reactivity; with a reduction on platelet aggregation. Wether this inhibition in platelet reactivity is due to tobacco effects in platelet signaling pathways or due to a pharmacodynamic interaction with antiplatelet therapies is not well stablished. Purpose Our aim was to study the influence of smoking habit in platelet reactivity and in the response to P2Y12 inhibitors. Methods Patients admitted in four tertiary care hospitals due to an acute coronary syndrome that undergone percutaneous coronary intervention (PCI) were consecutively and prospectively recruited. All the patients received dual antiplatelet therapy with aspirin and a P2Y12 inhibitor following current European Guidelines. Platelet function was assessed at day 1 and day 30 post-PCI by VerifyNow P2Y12, VASP (Vasodilator-stimulated phosphoprotein) y MEA (Multiple electrode aggregometry). Results A total of 1000 patients were enrolled, of whom 12 had to be excluded due to inaccurate processing of blood samples. 372 patients (37,6%) had smoking habit. Non-smoking patients showed higher prevalence of high blood pressure [423 (68.7%) vs 196 (52.7%)] and diabetes mellitus [213 (34.6%) vs 81 (21.8%)]. Smoking patients were younger [57.3 (9,6) years old vs 68.4 (11.1)], with higher incidence of acute coronary syndrome with ST segment elevation [184 patients (49,5%) vs 241 (39.1%), p&lt;0,001]. There were no differences in platelet function at day 1. When analysing platelet function 30 days post-PCI, a lower inhibition of platelet reactivity in non-smoking patients as compared with smoking patients was observed in those treated with clopidogrel, with higher prevalence of clopidogrel-resistance in non-smoking patients (VerifyNow, 51,2% prevalence of high platelet reactivity in non-smoking patients vs 34,9% 30 days after PCI, p=0,023). On the other hand, smoking patients that received ticagrelor did not show any differences. Patients with smoking habit treated with prasugrel showed a lower response of borderline statistical significance. Conclusion Smoking habit was associated with a lower response to prasugrel of borderline significance, and with higher response to clopidogrel, according with previous studies suggesting a pharmacodynamics interaction between tobacco use and P2Y12 inhibitors. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Fondo de Investigaciones Sanitarias (FIS)

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