Point-of-Care Platelet Function Tests

2014 ◽  
pp. 45-63
Author(s):  
Gabriele Casso ◽  
Fabio Lanzi ◽  
Carlo E. Marcucci
Keyword(s):  
Platelet Function ◽  
Point Of Care ◽  
Platelet Function Tests ◽  
Function Tests

“Aspirin - resistance”? A few critical considerations on definition, terminology, diagnosis, clinical value, natural course of atherosclerotic disease, and therapeutic consequences

VASA ◽  
2011 ◽  
Vol 40 (6) ◽  
pp. 429-438 ◽  
Author(s):  
Berent ◽  
Sinzinger
Keyword(s):  
Platelet Function ◽  
Point Of Care ◽  
Aspirin Resistance ◽  
Point Of View ◽  
Evidence Based ◽  
Platelet Function Tests ◽  
Clinical Value ◽  
Vascular Events ◽  
Therapeutic Consequences ◽  
Function Tests

Based upon various platelet function tests and the fact that patients experience vascular events despite taking acetylsalicylic acid (ASA or aspirin), it has been suggested that patients may become resistant to the action of this pharmacological compound. However, the term “aspirin resistance” was created almost two decades ago but is still not defined. Platelet function tests are not standardized, providing conflicting information and cut-off values are arbitrarily set. Intertest comparison reveals low agreement. Even point of care tests have been introduced before appropriate validation. Inflammation may activate platelets, co-medication(s) may interfere significantly with aspirin action on platelets. Platelet function and Cox-inhibition are only some of the effects of aspirin on haemostatic regulation. One single test is not reliable to identify an altered response. Therefore, it may be more appropriate to speak about “treatment failure” to aspirin therapy than using the term “aspirin resistance”. There is no evidence based justification from either the laboratory or the clinical point of view for platelet function testing in patients taking aspirin as well as from an economic standpoint. Until evidence based data from controlled studies will be available the term “aspirin resistance” should not be further used. A more robust monitoring of factors resulting in cardiovascular events such as inflammation is recommended.

Analysis of platelet function and dysfunction

2015 ◽  
Vol 35 (01) ◽  
pp. 60-72 ◽  
Author(s):  
K. Jurk
Keyword(s):  
Platelet Function ◽  
Posttranslational Modifications ◽  
Current Knowledge ◽  
Point Of Care ◽  
Screening Tests ◽  
Platelet Dysfunction ◽  
Platelet Function Tests ◽  
Function Tests ◽  
Diagnostic Potential ◽  
Platelet Function Disorders

SummaryAlthough platelets act as central players of haemostasis only their cross-talk with other blood cells, plasma factors and the vascular compartment enables the formation of a stable thrombus. Multiple activation processes and complex signalling networks are responsible for appropriate platelet function. Thus, a variety of platelet function tests are available for platelet research and diagnosis of platelet dysfunction. However, universal platelet function tests that are sensitive to all platelet function defects do not exist and therefore diagnostic algorithms for suspected platelet function disorders are still recommended in clinical practice.Based on the current knowledge of human platelet activation this review evaluates point-of-care related screening tests in comparison with specific platelet function assays and focuses on their diagnostic utility in relation to severity of platelet dysfunction. Further, systems biology-based platelet function methods that integrate global and specific analysis of platelet vessel wall interaction (advanced flow chamber devices) and posttranslational modifications (platelet proteomics) are presented and their diagnostic potential is addressed.

scholarly journals Point-of-care platelet function tests: relevance to arterial thrombosis and opportunities for improvement

2020 ◽  
Author(s):  
Diana A. Gorog ◽  
Richard C. Becker
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Arterial Thrombosis ◽  
Point Of Care ◽  
Laboratory Research ◽  
Platelet Function Tests ◽  
Function Tests ◽  
Antiplatelet Medication ◽  
Platelet Aggregometry

Abstract Studies using whole blood platelet aggregometry as a laboratory research tool, provided important insights into the mechanism and modulators of platelet aggregation. Subsequently, a number of point-of-care (POC) platelet function tests (PFTs) were developed for clinical use, based on the concept that an individual’s thrombotic profile could be assessed in vitro by assessing the response to stimulation of platelet aggregation by specific, usually solo agonists such as adenosine diphosphate (ADP), collagen and thrombin. However, adjusting antiplatelet medication in order to improve the results of such POC PFTs has not translated into a meaningful reduction in cardiovascular events, which may be attributable to important differences between the POC PFT techniques and in vivo conditions, including patient-to-patient variability. Important limitations of most tests include the use of citrate-anticoagulated blood. Citrate directly and irreversibly diminishes platelet function and even after recalcification, it may result in altered platelet aggregation in response to ADP, epinephrine or collagen, and interfere with thrombin generation from activated platelets. Furthermore, most tests do not employ flowing blood and therefore do not assess the effect of high shear forces on platelets that initiate, propagate and stabilize arterial thrombi. Finally, the effect of endogenous thrombolysis, due to fibrinolysis and dislodgement, which ultimately determines the outcome of a thrombotic stimulus, is mostly not assessed. In order to accurately reflect an individual’s predisposition to arterial thrombosis, future tests of thrombotic status which overcome these limitations should be used, to improve cardiovascular risk prediction and to guide pharmacotherapy.

Peri-operative antiplatelet therapy guided by point of care (POC) platelet function tests in cardiovascular surgery

2009 ◽  
Vol 96 (S1) ◽  
pp. 2-2
Author(s):  
C. W. Kotze ◽  
N. H. Harvey ◽  
S. Sepehripour ◽  
R. S. Kong ◽  
N. P. Hutchinson ◽  
...  
Keyword(s):  
Antiplatelet Therapy ◽  
Platelet Function ◽  
Cardiovascular Surgery ◽  
Point Of Care ◽  
Platelet Function Tests ◽  
Function Tests

scholarly journals Comparison of three common whole blood platelet function tests for in vitro P2Y12 induced platelet inhibition

2019 ◽  
Vol 50 (1) ◽  
pp. 135-143 ◽  
Author(s):  
Joao D. Dias ◽  
Torben Pottgiesser ◽  
Jan Hartmann ◽  
Daniel Duerschmied ◽  
Christoph Bode ◽  
...  
Keyword(s):  
Platelet Function ◽  
Whole Blood ◽  
Linear Models ◽  
Point Of Care ◽  
Platelet Function Tests ◽  
Blood Samples ◽  
P2y12 Inhibitors ◽  
Function Tests ◽  
Increased Risk

Abstract In the context of interventional cardiology, platelet function testing may identify patients treated with P2Y12-inhibitors at an increased risk of mortality, thrombosis and bleeding. Several whole blood point-of-care platelet function analyzers are available; however, inter-device differences have not been examined systematically. To compare three platelet function tests under standardized in vitro conditions. Healthy volunteer (n = 10) blood samples were spiked with increasing concentrations of ticagrelor (0–7500 ng/mL) and/or ASA (0–3280 ng/mL), measured on three platelet function analyzers (TEG®6s, Multiplate®, and VerifyNow®) and respective Effective Concentration (EC) levels EC10, EC50 and EC90 were calculated. Repeatability was assessed in a separate group of pooled blood samples (n = 10) spiked with ticagrelor at EC10, EC50 and EC90. ASA had no impact on ADP-activated channels for all three devices. TEG®6s was able to distinguish (p ≤ 0.05) between all ticagrelor EC zones; VerifyNow® and Multiplate® were able to distinguish between three and two zones, respectively. Multiplate® showed the largest window between EC10 and EC90 (19–9153 ng/mL), followed by TEG®6s (144–2589 ng/mL), and VerifyNow® (191–1100 ng/mL). Drug effect models distribution of disagreements were identified for TEG®6s (5.0%), VerifyNow® (8.3%), and Multiplate® (13.3%). TEG®6s showed the smallest average coefficient of variation between EC conditions (5.1%), followed by Multiplate® (14.1%), and VerifyNow® (17.7%). Linear models could be generated between TEG®6s and Multiplate®, but not VerifyNow®. Significant differences were found between whole blood point-of-care platelet function analyzers and the clinical impact of these differences needs to be further investigated.

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