Clopidogrel association test platelet function tests. Medical search. Frequent questions

Consequently, platelet reactivity in these patients remain higher, when compared to patients with wild-type CYP2C19. (ecrjournal.com)
However, the effect of strict, long-term glucose control on platelet reactivity in these patients remains uncertain. (revespcardiol.org)

Agreement between assays for measuring platelet reactivity was poor to moderate. (ahrq.gov)

Current guidelines of the European Society of Cardiology suggest starting clopidogrel therapy before any percutaneous coronary intervention (PCI) or when acute coronary syndrome (ACS) occurs [ 4 ]. (hindawi.com)
METHODS: The ADAPT-DES study was a multicenter registry of patients undergoing routine platelet function testing following percutaneous coronary intervention with DES. (duke.edu)
In the Gauging Responsiveness with A VerifyNow assay - Impact on Thrombosis And Safety (GRAVITAS) trial, patients with high platelet reactivity were randomised to receive clopidogrel 150 mg or 75 mg after percutaneous coronary intervention (PCI). (ecrjournal.com)
Association between high on-treatment platelet reactivity and occurrence of cerebral ischemic events in patients undergoing percutaneous coronary intervention. (cdc.gov)
High On-Treatment Platelet Reactivity Determinants on Dual Antiplatelet Therapy in Patients With Ischemic Heart Disease Before Elective Percutaneous Coronary Intervention]. (cdc.gov)

No significant associations were noted between clopidogrel resistance and recurrent ischaemic events. (bmj.com)
With a less-potent platelet inhibition, clot formation would continue to occur and these patients would remain more vulnerable to recurrent ischaemic events. (ecrjournal.com)

Personalised Approaches to Improving the Effect of Anti-platelet Agents: Where Do We Stand? (ecrjournal.com)
4 Test for both platelet reactivity and the CYP2C19 genetic variant are currently available, and have the theoretical potential to help clinicians to better choose the anti-platelet agent to be used, but the clinical evidence behind their use is still limited, preventing guidelines from routinely recommending these tests. (ecrjournal.com)
Similarly, in the Assessment by a Double Randomization of a Conventional Antiplatelet Strategy versus a Monitoring-guided Strategy for Drug-Eluting Stent Implantation and of Treatment Interruption versus Continuation One Year after Stenting (ARTIC) trial, a platelet-function monitoring strategy, coupled with adequate anti-platelet therapy adjustments, led to lower platelet reactivity, without any significant difference in clinical endpoints. (ecrjournal.com)
In the current edition of European Cardiology Review , a simulated analysis of DAPT post-ACS driven by testing for platelet reactivity gives some hope that a personalised approach to anti-platelet therapy is still worth exploring. (ecrjournal.com)

The reference range is a normal biphasic pattern of aggregation in response to specific platelet activators (see image below). (medscape.com)
Four tubes are needed for platelet aggregation testing. (medscape.com)
Seven tubes are required for full aggregation and secretion testing. (medscape.com)
Platelet aggregation studies test the clumping response of platelets to various platelet activators (eg, ADP, collagen, arachidonic acid, thrombin, epinephrine, ristocetin) as continuously recorded by a light transmission aggregometer. (medscape.com)
Platelet secretion defects can provide greater diagnostic sensitivity than platelet aggregation testing alone. (medscape.com)
Conditions associated with decreased platelet aggregation include suspected hereditary and acquired disorders of platelet function. (medscape.com)
The primary endpoint was assessment of platelet aggregation after stimulation with adenosine diphosphate 20 μM at 12-month follow-up. (revespcardiol.org)

Dual antiplatelet therapy with aspirin plus clopidogrel has become the standard treatment of patients undergoing coronary stenting [ 1 , 2 ]. (hindawi.com)
OBJECTIVES: In this analysis of 2-year outcomes in the ADAPT-DES (Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents) study, the authors sought to examine the independent associations between platelet reactivity to both aspirin and clopidogrel and subsequent outcomes. (duke.edu)

One hundred twenty-eight studies provided information on the ability of baseline on-clopidogrel platelet reactivity to predict clinical outcomes or platelet reactivity during followup. (ahrq.gov)
At baseline, 59 (95%) patients were taking clopidogrel alone with 3 (5%) on combined clopidogrel and aspirin. (bmj.com)
those with an ischaemic stroke had a non-significantly higher baseline P-selectin using the clopidogrel test as compared with those with no recurrence: 626 [380, 801] versus 406 [265, 609], p=0.08. (bmj.com)
These patients usually are stable enough to complete at least a cursory preparation for major spine surgery, including a detailed history and physical exam, complimented by baseline measures of coagulation and hemoglobin, type and cross for blood, and, if possible, an indication of cardiopulmonary function and appropriate functional testing if indicated. (renalandurologynews.com)
There were no differences between groups in baseline characteristics or platelet function. (revespcardiol.org)

Coronary angiogram, performed after administration of aspirin (100 mg) and of a 300 mg loading dose of clopidogrel, showed a critical stenosis of the left anterior descending artery involving the origin of the first diagonal branch and a severe short stenosis of a large, dominant circumflex artery at the level of the first marginal branch. (hindawi.com)

In the recently published Testing Responsiveness to Platelet Inhibition on Chronic Antiplatelet Treatment for Acute Coronary Syndromes (TROPICAL-ACS) trial, a guided de-escalation strategy from prasugrel to clopidogrel after an acute coronary syndrome (ACS), monitored by a platelet reactivity test, was non-inferior to conventional strategy with prasugrel. (ecrjournal.com)

This comparative effectiveness review evaluated the analytic validity, prognostic value, and comparative effectiveness of two types of medical tests (genetic testing for CYP2C19 variants and phenotypic testing to measure platelet reactivity) to identify patients who are most likely to benefit from clopidogrel-based antiplatelet therapy and to guide antiplatelet therapy in patient populations who are eligible to receive or are already receiving clopidogrel treatment. (ahrq.gov)
use of genetic testing (for CYP2C19 variants) or phenotypic testing (for platelet reactivity). (ahrq.gov)
One hundred six studies provided information on the ability of genetic testing for CYP2C19 variants to predict clinical outcomes or platelet reactivity during followup. (ahrq.gov)
1,2 Clopidogrel is administered as a pro-drug and needs to be metabolised by the cytochrome P450 enzymes (particularly by CYP2C19) in order to have biological activity. (ecrjournal.com)
Patients with loss of function (LOF) variants of the CYP2C19 gene have decreased serum levels of clopidogrel after oral administration. (ecrjournal.com)
In the Platelet Inhibition and Patient Outcomes (PLATO) genetic sub-study, which included slightly more than half of the 18,624 patients from the original trial, a trend was observed for reduced cardiovascular outcomes in patients with a CYP2C19 LOF allele treated with ticagrelor compared with clopidogrel, although no formal interaction was observed in this subgroup (p for interaction 0.46). (ecrjournal.com)
The Diagnostic Utility of the Point-of-Care CYP2C19 Genotyping Assay in Patients with Acute Coronary Syndrome Dosing Clopidogrel: Comparison with Platelet Function Test and SNP Genotyping. (cdc.gov)
CYP2C19 loss-of-function alleles are not associated with clinical outcome of clopidogrel therapy in patients treated with newer-generation drug-eluting stents. (cdc.gov)
Association of CYP2C19*2 polymorphism with clopidogrel response and 1-year major adverse cardiovascular events in a multiethnic population with drug-eluting stents. (cdc.gov)

Some patients may be on platelet inhibitors, including aspirin or clopidogrel, and it is unlikely that the surgeon would proceed with surgery while a patient is on these agents. (renalandurologynews.com)

No participants on aspirin and clopidogrel showed aspirin resistance. (bmj.com)

Methods Following written informed consent, independent patients with a recent non-cardioembolic ischaemic stroke or transient ischaemic attack, and taking clopidogrel, were enrolled. (bmj.com)
The purpose of this study was to determine the association of known variants in the platelet ADP receptors and cytochrome 450 enzymes in cats and determine their association with resistance to clopidogrel effect as assayed by multiple methods. (vin.com)
A meta-analysis of 22 studies of bacterial contamination rate estimates for apheresis (AP), platelet-rich plasma (PRP), and buffy coat (BC) collection methods found an overall mean contamination rate of 0.51 per 1000 components (95% confidence index [CI], 0.38-0.67). (medscape.com)

Characterization of patients with angioscopically-detected in-stent mural thrombi - genetics of clopidogrel responsiveness and generations of drug-eluting stents. (cdc.gov)

Associations were nonstatistically significant in meta-analyses of loss-of-function alleles and all-cause mortality, acute coronary syndromes, stroke, and bleeding events. (ahrq.gov)

Clopidogrel binds to the platelet receptor P2Y12 to prevent platelet clumping and decrease the risk of clots. (vin.com)

Clopidogrel major adverse events are represented by marrow suppression, manifesting with aplastic anaemia, thrombocytopenia and neutropenia. (hindawi.com)
Clopidogrel use is associated with an increased risk of bleeding and may cause haematological adverse effects, such as thrombotic thrombocytopenic purpura, haemolytic uremic syndrome, and bone-marrow suppression, manifesting with aplastic anaemia, thrombocytopenia [ 5 ], and neutropenia [ 6 , 7 ]. (hindawi.com)

CONCLUSIONS: The present study confirms the strong relationship of high platelet reactivity on clopidogrel to 2-year ischemic and bleeding outcomes after DES. (duke.edu)
As the myocardium becomes ischemic, coronary sinus blood pH falls, cellular potassium is lost, lactate accumulates, ECG abnormalities appear, and ventricular function (both systolic and diastolic) deteriorates. (msdmanuals.com)

Clopidogrel exerts its antiplatelet effect by inhibiting the binding of adenosine diphosphate (ADP) to its receptor (P2Y12) and consequent ADP-mediated platelet activation [ 3 ]. (hindawi.com)
This suggests that clopidogrel may have modes of action unrelated to inhibition of the P2Y12 receptor, or that other pathways are at play. (vin.com)
However, in cats with mutations to the P2Y12 receptor, clopidogrel effect was absent or diminished. (vin.com)
Interestingly, clopidogrel does not bind to the P2Y1 receptor, and so the mutation in this gene may not directly influence clopidogrel binding, but other downstream effects of P2Y12 inhibition. (vin.com)
Clopidogrel is the most widely prescribed P2Y12 inhibitor in the world despite the development of newer and more potent agents. (ecrjournal.com)

For the pharmacogenetic associations listed in this table, the FDA has evaluated and believes there is sufficient scientific evidence to suggest that subgroups of patients with certain genetic variants, or genetic variant-inferred phenotypes (such as affected subgroup in the table below), are likely to have altered drug metabolism, and in certain cases, differential therapeutic effects, including differences in risks of adverse events. (fda.gov)
Nor is the table intended to make an assessment on the safe and effective use of, or regulatory requirements for, tests that detect variants in the referenced genes, or to provide comprehensive information on the described gene-drug interactions. (fda.gov)
This version of the table is limited to pharmacogenetic associations that are related to drug metabolizing enzyme gene variants, drug transporter gene variants, and gene variants that have been related to a predisposition for certain adverse events. (fda.gov)

Scholars@Duke publication: Impact of Aspirin and Clopidogrel Hyporesponsiveness in Patients Treated With Drug-Eluting Stents: 2-Year Results of a Prospective, Multicenter Registry Study. (duke.edu)
BACKGROUND: The relationship between platelet reactivity and long-term adverse events following implantation of drug-eluting stents (DES) has been incompletely characterized. (duke.edu)

However, none has addressed the association between FAR and severity of coronary artery disease (CAD), clinical outcome in NSTE-ACS patients firstly implanted with drug-eluting stent (DES). (hindawi.com)
Results of the Clopidogrel After Surgery for Coronary Artery Disease (CASCADE) trial confirmed that this practice independently associated with improved graft patency, as demonstrated by coronary angiography and saphenous vein graft intravascular ultrasonography. (medscape.com)

The authors found that concentrations of clopidogrel and its active metabolite did not correlate with the degree of platelet function inhibition. (vin.com)

11% of patients taking clopidogrel showed resistance. (bmj.com)
However, clopidogrel is not consistently effective and resistance has been described in all species tested. (vin.com)
Specifically, the mutation P2RY1:A236G was associated with significant resistance to clopidogrel even after multivariate regression. (vin.com)
The authors suggest that variations in the P2Y receptors on platelet surfaces may play a significant role in resistance to clopidogrel, and in fact that this may be a more prominent determining factor in clopidogrel resistance than variations in CYP enzymes. (vin.com)

Pharmacogenomic testing for mutations affecting clopidogrel metabolism has not been widely evaluated to date. (ecrjournal.com)

Studies had to report information on the analytic validity, prognostic ability for intermediate (platelet reactivity) or clinical outcomes, use of tests to guide antiplatelet therapy, or adverse events from testing itself or from test-directed treatment. (ahrq.gov)
Clopidogrel has mostly replaced the use of ticlopidine due to its more favourable adverse event profile. (hindawi.com)
Between years 1 and 2, high platelet reactivity was not associated with the very late ST and in patients on aspirin monotherapy, aspirin hyporesponsiveness was not associated with adverse outcomes. (duke.edu)
Specific information regarding therapeutic management is provided for some pharmacogenetic associations listed in the table, but most of the associations listed have not been evaluated in terms of the impact of genetic testing on clinical outcomes, such as improved therapeutic effectiveness or increased risk of specific adverse events. (fda.gov)

Clopidogrel-Induced Neutropenia after Coronary Stenting: Is Cilostazol a Good Alternative? (hindawi.com)

The primary aim was to assess the proportion of patients who are insensitive to clopidogrel. (bmj.com)
The CAPRIE trial, which included 9.599 patients treated with clopidogrel, showed a low annual incidence (0.05%) of severe neutropenia, considered as neutrophil count below 0.45 × 10 9 /L [ 4 ]. (hindawi.com)
Healthcare providers should ask patients about any of these medications that may have been taken within 2 weeks before testing. (medscape.com)
Platelet inhibitory effect of clopidogrel in patients treated with omeprazole, pantoprazole, and famotidine: a prospective, randomized, crossover study. (medscape.com)
Pharmacogenetic tests, along with other information about patients and their disease or condition, can play an important role in drug therapy. (fda.gov)
Tests that are essential for the safe and effective use of a therapeutic product, including those that identify patients for which the drug is contraindicated, are companion diagnostics. (fda.gov)
The FDA has opened a docket for stakeholders-including scientific and medical communities, patients, providers, and industry-to offer specific comments on pharmacogenetic associations that the FDA should or should not include in this table, along with the rationale and underlying evidence that supports the pharmacogenetic association. (fda.gov)
Intensive glucose control with insulin in patients with an acute coronary syndrome reduces platelet reactivity during hospitalization, compared to conventional control. (revespcardiol.org)
180 mg/dL), on platelet reactivity after hospital discharge in patients with an acute coronary syndrome and hyperglycemia. (revespcardiol.org)
Chez les patients hypertendus, le taux de mortalité était plus élevé uniquement chez les patients admis pour un infarctus du myocarde avec sus-décalage du segment ST. Après ajustement des résultats en fonction des variables de référence, l'hypertension s'est révélé être un facteur prédictif indépendant de l'insuffisance cardiaque (OR = 1,31) et de l'accident vasculaire cérébral (OR = 2,47). (who.int)

In a recent report on outcomes after thrombolysis for ALLI, end-stage renal disease and poor pedal outflow were predictors for limb loss after multi-variable testing, whereas diabetes mellitus (DM) and the Rutherford Classification were not [ 2 ]. (springer.com)

Significant variability in P-VASP expression was seen that was not correlated significantly with clopidogrel use or genotype, leading the authors to posit that P-VASP expression may not be an ideal test of clopidogrel effect. (vin.com)
Although the higher dose of clopidogrel reduced platelet reactivity significantly (by 22%), no difference in the composite of cardiovascular death, nonfatal MI or stent thrombosis was found. (ecrjournal.com)

Recently, numerous studies have shown that the fibrinogen-to-albumin ratio (FAR) does not only have a high prognostic value in certain types of cancer including gastric, colorectal, and gallbladder cancer [ 8 - 10 ] but also have an association with the presence and poor clinical outcome of cardiovascular disease [ 11 - 14 ]. (hindawi.com)

When clopidogrel toxicity occurs, there are few and unsubstantiated alternative treatments and thus, in these cases, medical decisions may be very difficult. (hindawi.com)
We report a case of clopidogrel-induced bone marrow toxicity manifesting with severe neutropenia in a patient treated with multiple coronary stents and provide suggestions for an alternative treatment. (hindawi.com)
When clopidogrel toxicity occurs, little is known about the efficacy and safety of alternative treatments, and thus, in these cases, medical decisions may be very difficult. (hindawi.com)
If no statements related to efficacy or toxicity are provided, the scientific evidence the FDA reviewed was considered insufficient to support such associations. (fda.gov)

During the cascade process, the body sequentially activates coagulation factors , which are proteins that create a net of fibrin threads, which weave them through the platelet plug making a stable firm fibrin blood clot, whilst still allowing blood to flow through the damage vessel. (labtestsonline.org.uk)

Nevertheless, it is thought that the actual incidence of clopidogrel myelotoxicity could be somewhat underestimated [ 7 ]. (hindawi.com)
[ 4 , 6 ] The higher incidence of bacterial transmission via platelets has been attributed to the difference in storage temperatures. (medscape.com)

Coronary stent restenosis and the association with allergy to metal content of 316L stainless steel. (cdc.gov)

Samples were tested before initiation of therapy and after 10-14 days of clopidogrel (the maximal effect is usually reached by 4 days post-initiation). (vin.com)

We searched MEDLINE®, the Cochrane Central Trials Registry, the Cochrane Database of Systematic Reviews, the Human Genome Epidemiology Network database, and the National Institutes of Health Genetic Association Database, from inception to July 27, 2012. (ahrq.gov)
In particular, each patient's genetic makeup is only one of many factors that may impact drug concentrations and response, highlighting the fact that information provided in this table is limited to certain pharmacogenetic associations only and does not provide comprehensive information needed for safe and effective use of a drug. (fda.gov)

Conclusions Remote measurement of platelet function assessed using the platelet surface expression of P-selectin is feasible. (bmj.com)

The secondary aim was to assess the association between insensitivity to clopidogrel and recurrent cerebrovascular events. (bmj.com)

The risk of thromboembolism may be decreased with antiplatelet drugs such as clopidogrel. (vin.com)
These drugs aren't routinely used because they are still being tested. (epnet.com)

The fact that the FDA has included a particular gene-drug interaction in the table does not necessarily mean the FDA advocates using a pharmacogenetic test before prescribing the corresponding medication, unless the test is a companion diagnostic. (fda.gov)

EGCG is more tested and while it does effect many things, we have a better understanding of what it does. (blogspot.com)

When blood flow stops, brain cells do not receive the oxygen and glucose they require to function and a stroke occurs. (medicinenet.com)

Consider additional follow-up and diagnostic testing. (nih.gov)
Wallach J. Interpretation of Diagnostic Tests . (medscape.com)

Clopidogrel is used to prevent heart attack and stroke. (epnet.com)
It may help to function when given after a stroke. (epnet.com)
Some migraine headache episodes can even mimic stroke with loss of function of one side of the body or vision or speech problems. (medicinenet.com)
In 2014, the American Heart Association and the American Stroke Association released the first guidelines to specifically address stroke prevention in women. (adam.com)
The consequences of a stroke, the type of functions affected, and the severity depend on where in the brain it has occurred and the extent of the damage. (adam.com)

1-6 Unlike other secondary prevention interventions such as blood pressure and lipid lowering, antithrombotic antiplatelet agents are prescribed and administered without ongoing monitoring as there are no widely available, affordable, effective and validated tests of platelet function. (bmj.com)
The utility of evaluating platelet reactivity to tailor antiplatelet strategies has been widely studied, with disappointing findings. (ecrjournal.com)
8 Given the uncertainty of evidence and the high cost of the alternative agents to clopidogrel and the cost of the platelet reactivity tests, local cost-effectiveness analyses are necessary before widely adopting these strategies. (ecrjournal.com)

Only 12 studies provided information on analytic test performance, and they reported variable results. (ahrq.gov)

No significant bleeding was observed post-operatively, and she was discharged by post-operative day 15 with normal biventricular systolic function. (stanfordchildrens.org)

The study was limited to cats with HCM, which, while the most common use of clopidogrel is not the only indication for its use. (vin.com)

Blood tests revealed severe leukopenia (white cells 1 × 10 3 / μ L) with marked neutropenia (neutrophils 3%), anaemia (haemoglobin 9.9 g/dL), and an important rise in inflammatory markers (C-reactive protein 122 mg/dL). (hindawi.com)
Platelet function was assessed by whole blood aggregometry using the Multiplate system, and flow cytometry to measure phosphorylation of P-VASP and P-selectin. (vin.com)
The dose varies and is chosen based on blood tests that check how you clot. (epnet.com)
You won't need blood tests while you are on it. (epnet.com)
Aspirin lowers blood clotting by affecting platelets. (epnet.com)
In 2009, the American Association of Blood Banks (AABB) published a detailed description of 68 infectious agents capable of being transmitted by blood transfusion and prioritizing emerging infectious diseases for which there was not yet an implemented intervention. (medscape.com)
The estimated residual risk of contamination of blood products with bacterial agents is 1 in 5,000 for platelets and 1 in 30,000 for red blood cells. (medscape.com)
During haemostasis, the injured blood vessel becomes narrower (constricts) to reduce blood flow, cells in the blood called platelets stick (adhere) to the injury site and clump together to form a loose platelet plug and the coagulation cascade is triggered (initiated). (labtestsonline.org.uk)

The brain controls the major functions of human life. (homeopathydallas.com)

Anatomy2

Diseases9

Chemicals and Drugs28

Analytical, Diagnostic and Therapeutic Techniques and Equipment22

Psychiatry and Psychology4

Phenomena and Processes25

Disciplines and Occupations1

Anthropology, Education, Sociology and Social Phenomena2

Information Science2

Health Care6

Reactivity in these patients2

Measuring platelet reactivity1

Percutaneous coronary int5

Recurrent ischaemic events2

Anti-platelet4

Aggregation7

Dual antiplatelet therapy2

Baseline5

Loading dose1

Antiplatelet Treatment1

CYP2C199

Inhibitors1

Aspirin resistance1

Methods3

Responsiveness1

Loss-of-function alle1

Clots1

Thrombocytopenia2

Ischemic2

P2Y125

Variants3

Drug-Elutin2

Coronary artery2

Inhibition1

Resistance4

Mutations1

Adverse4

Cilostazol1

Patients10

Outcomes1

Significantly2

Cardiovascular1

Toxicity4

Fibrin1

Incidence2

Stent1

Therapy1

Genetic2

Conclusions1

Events1

Drugs2

Interaction1

Effect1

Glucose1

Diagnostic2

Stroke5

Widely3

Results1

Systolic1

Indication1

Blood8

Major1