scholarly journals The importance of tests applied to evaluate the effectiveness of antiplatelet therapy in patients with recurrent coronary stent thrombosis

2009 ◽  
Vol 66 (4) ◽  
pp. 328-332
Author(s):  
Aleksandra Grdinic ◽  
Danilo Vojvodic ◽  
Vesna Ilic ◽  
Zvonko Magic ◽  
Nina Djukanovic ◽  
...  
Keyword(s):  
Antiplatelet Therapy ◽  
Stent Thrombosis ◽  
Platelet Function ◽  
Coronary Intervention ◽  
P2y12 Receptor ◽  
Cardiac Events ◽  
Major Haplotype ◽  
Function Analyzer ◽  
Insufficient Response ◽  
Platelet Function Analyzer

Background. Stent thrombosis is potentially lethal complication with huge economic burden. The role of insufficient response to antiplatelet therapy is still unclear reason for its occurrence. Case report. We presented 54-year-old man with recurrent stent thrombosis on the 4th, 9th and 12th day after the primary percutaneous coronary intervention in spite of double antiaggregation therapy (aspirin+ clopidogrel). All possible procedural causes were excluded and reimplantation of intracoronary stent was insufficient to resolve the problem, so four platelet tests were performed: flow cytometry, Platelet Function Analyzer-100 test, aggregometry, and determination of gene polymorphism for P2Y12 receptor (directly involved in the mechanism of thienopyridine), and GPIIbIIIa receptor (final receptor in aggregation). The patient was the carrier of the major haplotype H1H1 for P2Y12 receptor and minor A1A2 for GPIIbIIIa receptor. The results of all the performed tests showed insufficient antiplatelet effect of aspirin and sufficient response to thienopyridin (not to clopidogrel, but to ticlopidine). Conclusion. Performance of platelet function tests is necessary in the case of major adverse cardiac events especially stent thrombosis, after implantation of intracoronary stent.

scholarly journals Adequate Platelet Function Inhibition Confirmed by Two Inductive Agents Predicts Lower Recurrence of Ischemic Stroke/Transient Ischemic Attack

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Lulu Zhang ◽  
Xiaowei Hu ◽  
Juehua Zhu ◽  
Xiuying Cai ◽  
Yan Kong ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Antiplatelet Therapy ◽  
Platelet Function ◽  
Adenosine Diphosphate ◽  
Aggregation Rate ◽  
Function Analyzer ◽  
Ischemic Attack ◽  
Platelet Function Analyzer ◽  
Platelet Functions

Background. The correlation between platelet function and recurrent ischemic stroke or TIA remains uncertain. Objective. To investigate two inductive agents to detect platelet functions and assess associations with recurrent ischemic stroke/TIA. Method. The study included 738 ischemic stroke/TIA patients. On days 0, 3, and 9 after antiplatelet therapy, platelet function tests were determined by maximum aggregation rate (MAR) using a PL-11 platelet function analyzer and phase matching reagents. Two induction agents were used: arachidonic acid (AA) and adenosine diphosphate (ADP). At 3-month follow-up, recurrence of stroke/TIA was recorded. Result. Cut-off values of adequate platelet function inhibition were MARADP < 35% and MARAA < 35%. Data showed that antiplatelet therapy could reduce the maximum aggregation rate. More importantly, adequate platelet function inhibition of either MARADP or MARAA was not associated with the recurrence of stroke/TIA, but adequate platelet function inhibition of not only MARADP but also MARAA predicts lower recurrence (0/121 (0.00%) versus 18/459 (3.92%), P = 0.0188). Conclusion. The platelet function tested by PL-11 demonstrated that adequate inhibition of both MARADP and MARAA could predict lower risk of ischemic stroke/TIA recurrence.

scholarly journals Monitoring of Clopidogrel Action: Comparison of Methods

2005 ◽  
Vol 51 (6) ◽  
pp. 957-965 ◽  
Author(s):  
Jörg Geiger ◽  
Lino Teichmann ◽  
Ralf Grossmann ◽  
Barsom Aktas ◽  
Udo Steigerwald ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Platelet Function ◽  
Significant Proportion ◽  
Coronary Intervention ◽  
Platelet Response ◽  
Closure Time ◽  
Vasp Phosphorylation ◽  
Function Analyzer ◽  
Potent Drug ◽  
Platelet Function Analyzer

Abstract Background: Clopidogrel is a potent drug for prevention of adverse effects during and after coronary intervention. Increasing experience indicates that a significant proportion of patients do not respond adequately to clopidogrel. Because failure of antiplatelet therapy can have severe consequences, there is need for a reliable assay to quantify the effectiveness of clopidogrel treatment. Methods: Of 24 healthy volunteers admitted to the study, 18 were treated for 1 week with clopidogrel (300-mg loading dose and 75-mg maintenance dose), and 6 with placebo. Platelet function was monitored by 2 assays, based on flow cytometry and enzyme immunoassay, that measure the phosphorylation status of vasodilator-stimulated phosphoprotein (VASP) and by aggregometry, flow cytometry of P-selectin, and the platelet function analyzer at baseline, on days 1–5, and on day 9 of treatment. Results: Aggregometry and VASP phosphorylation revealed a loss of platelet response to ADP within 12 h after clopidogrel intake. The phosphorylation status of VASP correlated with the inhibition of platelet aggregation. In contrast, neither P-selectin expression nor PFA-100 closure time was a clear indicator of clopidogrel effects on platelets. Conclusions: VASP phosphorylation assays are reliable for quantifying clopidogrel effects. Because the VASP assay directly measures the function of the clopidogrel target, the P2Y12 receptor, the assay is selective for clopidogrel effects rather than effects of other platelet inhibitors commonly in use.

Quantifying the Effect of Antiplatelet Therapy

2006 ◽  
Vol 105 (4) ◽  
pp. 676-683 ◽  
Author(s):  
Seema Agarwal ◽  
Margaret Coakely ◽  
Kalpana Reddy ◽  
Anne Riddell ◽  
Susan Mallett
Keyword(s):  
Antiplatelet Therapy ◽  
Platelet Function ◽  
Light Transmission ◽  
Point Of Care ◽  
Perioperative Bleeding ◽  
Light Transmission Aggregometry ◽  
Function Analyzer ◽  
Platelet Function Analyzer ◽  
Ischemic Events ◽  
Good Agreement

Background Antiplatelet therapy with aspirin and clopidogrel is known to confer protection against ischemic events. Increasing numbers of patients are presenting for surgery while taking these drugs. This may lead to an increase in perioperative blood loss, particularly in those who have a heightened response to the drugs. Identifying these patients preoperatively would allow us to plan appropriate management. Methods The antiplatelet effect of aspirin and/or clopidogrel was measured using two point-of-care monitors: the platelet function analyzer (PFA-100; Dade, Miami, FL) and the modified thromboelastograph (mTEG; Haemoscope Corp., Niles, IL). This was compared with optical light transmission aggregometry. Results All people taking aspirin displayed a definitive aspirin effect on aggregometry (n = 20). Ninety percent of these were identified by modified thromboelastography (n = 18). Seventy percent were identified by the platelet function analyzer (n = 14). Fifty percent of people taking clopidogrel displayed a definitive response to the drug on aggregometry. Seventy percent of these were identified on modified thromboelastography (n = 7). None were identified by the platelet function analyzer. There was good agreement between the results of the aggregometry and modified thromboelastography in clopidogrel patients (kappa = 0.81). Conclusion The search for a point-of-care monitor of platelet function has been the focus of much research. This study has shown that the modified thromboelastograph can be used for monitoring the effect of clopidogrel as well as aspirin. It potentially has a wide scope to be used for the monitoring of effectiveness of therapy as well as a possible predictor of perioperative bleeding.

Monitoring Acetylsalicylic Acid Effects with the Platelet Function Analyzer PFA-100

2005 ◽  
Vol 31 (04) ◽  
pp. 411-415 ◽  
Author(s):  
Martin Feuring ◽  
Armin Schultz ◽  
Ralf Losel ◽  
Martin Wehling
Keyword(s):  
Acetylsalicylic Acid ◽  
Platelet Function ◽  
Function Analyzer ◽  
Platelet Function Analyzer

scholarly journals Variables influencing Platelet Function Analyzer-100TM closure times in healthy individuals

2005 ◽  
Vol 130 (5) ◽  
pp. 759-767 ◽  
Author(s):  
Hannelore Haubelt ◽  
Christof Anders ◽  
Anette Vogt ◽  
Petra Hoerdt ◽  
Ulrich Theo Seyfert ◽  
...  
Keyword(s):  
Platelet Function ◽  
Healthy Individuals ◽  
Function Analyzer ◽  
Platelet Function Analyzer
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