Platelet Function Tests (platelet + function_test)

Distribution by Scientific Domains


Selected Abstracts


Levosimendan has an inhibitory effect on platelet function

AMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2008
at Kaptan
Levosimendan enhances cardiac contractility by increasing myocyte sensitivity to calcium, and induces vasodilatation. Although studies have evaluated the efficacy of levosimendan in heart failure, it is not clear whether it might produce functional influence on platelet response. In this study, the effect of levosimendan on platelet aggregation was investigated. Platelet function tests were performed in 12 healthy male volunteers. Three concentrations of levosimendan solution were prepared that would result in 10, 25, and 45 ng/ml levosimendan concentrations in the blood similar to that observed after clinical therapeutic intravenous application of 0.05,0.1 ,g/kg/min. Each concentration of levosimendan solution and a control diluent without levosimendan were incubated with whole blood at 37°C. After incubation for 15 min, aggregation responses were evaluated with adenosine diphosphate (ADP) (5 and 10 ,M) and collagen (2 and 5 ,g/ml) in platelet-rich plasma. Preincubation with all dilutions of levosimendan inhibited aggregation of platelets induced by ADP and collagen significantly. Levosimendan also inhibited significantly the secondary wave of platelet aggregation induced by ADP. The results showed that there was a relationship between levosimendan concentration and inhibition of platelet aggregation. In conclusion, this study with an in vitro model showed that levosimendan had a significant inhibitory effect on platelets in clinically relevant doses. Am. J. Hematol., 2008. © 2007 Wiley-Liss, Inc. [source]


ADP-induced platelet aggregation in acute ischemic stroke patients on aspirin therapy

EUROPEAN JOURNAL OF NEUROLOGY, Issue 12 2008
J.-K. Cha
Background and purpose:, Aspirin is an important therapeutic regimen to prevent the recurrent ischemic events or death after acute ischemic stroke. In this study, we evaluated the relationship between the extent of adenosine diphosphate (ADP) -induced platelet aggregation and outcome in acute ischemic stroke patients on aspirin therapy. Methods:, We selected 107 acute ischemic stroke patients who had been prescribed aspirin and evaluated platelet function test by using optic platelet aggregometer test after 5 days of taking it and investigated the prognosis 90 days after ischemic events. Kaplan,Meyer curve was used for survival analysis. Results:, After stratification of the subjected patients by tertiles of ADP-induced platelet aggregation, the events rates were 7.4%, 9.3% and 30.8% (P = 0.023). In multiple logistic regression analysis, old age over 70 years (OR, 13.7; 95% CI, 2.14,88.07; P = 0.001) and the increased ADP-induced platelet aggregation had independent significance to the risk of primary end-points after acute ischemic stroke (OR, 1.1; 95% CI 1.01 to 1.20; P = 0.026). Conclusions:, This study showed that the increased ADP-induced platelet aggregation under using aspirin is associated with poor outcome after acute ischemic stroke. [source]


Comparison between hirudin and citrate in monitoring the inhibitory effects of P2Y12 receptor antagonists with different platelet function tests

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2009
C. A. C. M. PITTENS
[source]


Long-term Management of an Implantable Left Ventricular Assist Device Using Low Molecular Weight Heparin and Antiplatelet Therapy: A Possible Alternative to Oral Anticoagulants

ARTIFICIAL ORGANS, Issue 5 2007
Bart Meuris
Abstract:, Between January 2004 and December 2005, out of 14 patients with decompensated heart failure who were treated with an INCOR left ventricular assist device (Berlin Heart AG, Berlin, Germany), 10 patients were kept on a long-term regime of low molecular weight heparin (LMWH) and antiplatelet therapy. The treatment objective was bridge-to-transplantation. All patients received LMWH in therapeutic doses according to body weight, in combination with daily aspirin 160 mg, clopidogrel 75 mg, and three times dipyridamole 75 mg. Effectiveness of the low molecular weight regime was monitored through measurement of antifactor Xa activity (base and peak levels). Antiplatelet therapy was monitored through weekly platelet function tests. Within this group of 10 patients, six patients successfully received transplants and four patients died, the latest death after 405 days of INCOR support. Causes of death were sepsis, intestinal hemorrhage, acute right ventricular failure, and one major stroke. Long-term management of INCOR assist devices using a combination of LMWH and antiplatelet therapy is feasible. This treatment strategy can serve as an alternative to oral anticoagulants. [source]


Assessing the Current Role of Platelet Function Testing

CLINICAL CARDIOLOGY, Issue S1 2008
Eugene Braunwald
Abstract In vitro platelet function tests are commonly applied in research and offer justification for using antiplatelet therapy. However, studies assessing the ability of standardized platelet function tests to predict patients' clinical response to aspirin or clopidogrel have generated contradictory results. At this time, there is no standardized definition for resistance to antiplatelet therapy, and the appropriate treatment of patients who are hyporesponsive to these agents is not known. Although such tests have a role in research, their place in guiding therapy remains to be established, and prospective trials are urgently needed. The ideal platelet function test for clinical practice would be rapid, easy-to-use, inexpensive, and reliable. Copyright © 2008 Wiley Periodicals, Inc. [source]