scholarly journals Platelet Function Tests: A Review of Progresses in Clinical Application

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jae-Lim Choi ◽  
Shuhua Li ◽  
Jin-Yeong Han
Keyword(s):  
Clinical Application ◽  
Platelet Function ◽  
Immunomodulatory Activity ◽  
Platelet Function Tests ◽  
Function Tests ◽  
Mediators Of Inflammation ◽  
Increased Risk ◽  
Integral Role ◽  
Thrombotic Diseases

The major goal of traditional platelet function tests has been to screen and diagnose patients who present with bleeding problems. However, as the central role of platelets implicated in the etiology of arterial thrombotic diseases such as myocardial infarction and stroke became widely known, platelet function tests are now being promoted to monitor the efficacy of antiplatelet drugs and also to potentially identify patients at increased risk of thrombosis. Beyond hemostasis and thrombosis, an increasing number of studies indicate that platelets play an integral role in intercellular communication, are mediators of inflammation, and have immunomodulatory activity. As new potential biomarkers and technologies arrive at the horizon, platelet functions testing appears to take on a new aspect. This review article discusses currently available clinical application of platelet function tests, placing emphasis on essential characteristics.

scholarly journals Utility of Platelet Function Tests: A Recent Review Round Up

2019 ◽  
Vol 03 (01) ◽  
pp. 24-27
Author(s):  
Sandeep Sharan ◽  
Ajay Gandhi ◽  
Poonam Malhotra Kapoor
Keyword(s):  
Cardiac Surgery ◽  
Coronary Artery ◽  
Platelet Function ◽  
Postoperative Bleeding ◽  
Platelet Dysfunction ◽  
Platelet Function Tests ◽  
Excessive Bleeding ◽  
Function Tests ◽  
Increased Risk ◽  
Hemostatic Therapy

AbstractPatients undergoing cardiac surgery are at risk of excessive bleeding and associated complications. Excessive bleeding during and after cardiac surgery has an incidence of ~20%. Massive bleeding and subsequent requirement for blood product administration and mediastinal re-exploration is associated with significant morbidity and mortality. Postoperative, nonsurgical bleeding in cardiac surgical patients is often multifactorial. Platelet dysfunction, excessive fibrinolysis, hypothermia, preoperative anemia, and deficiency of coagulation factors or their dilution are all suggested etiologies of postoperative bleeding. Among these, the most important is thought to be platelet dysfunction, which occurs as a result of the interplay of acquired and pharmacologically induced factors. Patients suffering from coronary artery disease are usually advised to stop antiplatelet medication a few days prior to coronary artery bypass grafting (CABG) to reduce the incidence of postoperative bleeding. However, patients who are still on antiplatelet drugs are at an increased risk of postoperative bleeding. Currently, the transfusion of blood and blood components to manage postoperative bleeding after CABG remains largely empirical, with considerable variation among institutions. Algorithm-based hemostatic therapy has been shown to be superior to empiric hemostatic therapy that is based on clinical judgment. Hence, there is a need to have objective tests to demonstrate platelet dysfunction before platelet transfusion. Several devices of platelet function tests have been reported in clinical studies to evaluate platelet dysfunction and quantify the need for antiplatelet therapy

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.

Impaired platelet function and peripartum bleeding in women with Gaucher disease

2011 ◽  
Vol 105 (03) ◽  
pp. 509-514 ◽  
Author(s):  
Michal Simchen ◽  
Rotem Oz ◽  
Boris Shenkman ◽  
Ari Zimran ◽  
Deborah Elstein ◽  
...  
Keyword(s):  
Platelet Function ◽  
Gaucher Disease ◽  
Enzyme Treatment ◽  
Study Cohort ◽  
Platelet Function Tests ◽  
Enzyme Replacement ◽  
Function Tests ◽  
Increased Risk ◽  
Type 1 Gaucher Disease

SummaryThe risk of bleeding during delivery may be increased in women with Gaucher disease. We aimed to evaluate potential predictors for peripartum haemorrhage (PPH) during childbirth in these patients, while focusing upon coagulation tests and platelet function assays. Women with type 1 Gaucher disease who gave birth at Sheba Medical Center between 1999–2009 comprised the study cohort. Data collected included disease history, enzyme treatment, platelet counts, delivery and pregnancy outcome. PPH was defined as excessive bleeding during or immediately following delivery. Coagulation studies and platelet function tests, including aggregometry and cone and platelet (CPA) analyses, were performed on all women. We compared women with PPH (bleeders) and non-bleeders. Furthermore, women with abnormal CPA platelet function tests were compared with those with normal CPA platelet function with regards to the risk for PPH in at least one pregnancy. Forty-five pregnancies of 20 women were studied. Six women received enzyme replacement therapy during pregnancy. Mean platelet count prior to delivery was 83,000/μl ± 35,000/μl. Fourteen out of 45 (31%) deliveries were complicated by PPH. Neither thrombocytopenia nor enzyme therapy predicted PPH. Twelve out of 13 women with PPH (92.3%) versus 2/7 non-bleeders (28.6%) had impaired platelet aggregation (less than the 3rd percentile of normal average aggregate size values), when tested by CPA, (odds ratio [OR] 17.8, 95% confidence interval [CI] 2.5; 126.2; p=0.007). Notably, 78.6% of women with impaired CPA aggregation developed PPH during at least one delivery, as opposed to 16.7% of those with normal CPA platelet function tests (OR 11.6, 95% CI 1.7–77.7, p=0.018). In conclusion, women with type 1 Gaucher disease who have abnormal platelet function tests may have an increased risk of PPH.

Antiplatelet Therapy in Acute Coronary Syndromes. Lights and Shadows of Platelet Function Tests to Guide the Best Therapeutic Approach

2020 ◽  
Vol 18 (3) ◽  
pp. 262-272 ◽  
Author(s):  
Giovanni Cimmino ◽  
Emanuele Gallinoro ◽  
Luigi Di Serafino ◽  
Nicola De Luca ◽  
Plinio Cirillo
Keyword(s):  
Antiplatelet Therapy ◽  
Platelet Activation ◽  
Platelet Function ◽  
Acute Coronary Syndromes ◽  
Clinical Decision Making ◽  
Platelet Reactivity ◽  
Platelet Function Tests ◽  
Function Tests ◽  
Increased Risk ◽  
Coronary Syndromes

The key role of platelets in pathophysiology of Acute Coronary Syndromes (ACS) has been well recognized. Platelet activation and aggregation, together with tissue factor-pathway activation, lead to acute thrombus formation in the coronary vessels at sites of plaque rupture. Thus, antiplatelet therapy with drugs able to interfere with platelet activation/aggregation represents a cornerstone of ACS treatment in intensive care units and catheterisation labs. Several observational studies have described that residual high platelet reactivity, despite antiplatelet therapy, is associated with increased risk of nonfatal Myocardial Infarction (MI), definite/probable stent thrombosis and cardiovascular mortality. Thus, assessment of platelet function with reliable and reproducible platelet function tests might be crucial to identify patients at high risk of thrombosis or not responding to ongoing antiplatelet strategies. However, despite this promising background, some randomized clinical trials have failed to demonstrate improvement in outcomes when using platelet function tests for clinical decision-making. This review, after describing platelet biology and pathophysiology of ACS, briefly considers the drugs currently approved for use in patients with ACS or treated by the percutaneous coronary intervention (PCI). Finally, we provide an updated overview of the current methods to evaluate platelet reactivity in the clinical setting of ACS illustrating their potential advantages/limitations in current clinical practice.

“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.

LACK OF CORRELATION BETWEEN INTRAPLATELET cAMP INCREASE AND SYSTEMIC CIRCULATORY EFFECTS

1987 ◽  
Author(s):  
W Haarmann ◽  
H Weisenberger
Keyword(s):  
Platelet Function ◽  
Circulatory System ◽  
Human Platelets ◽  
Platelet Function Tests ◽  
Inotropic Effects ◽  
Circulatory Effects ◽  
Function Tests ◽  
Drug Concentrations ◽  
Camp Metabolism ◽  
The Difference

Compounds inhibiting platelet function by acting on platelet cAMP metabolism usually also have effects on the circulatory system, i.e. they decrease systemic blood pressure (bp) and are positive inotropic. For several compounds selected because of their distinct platelet inhibitory effects, the influence on these parameters in animals and on the cAMP metabolism in human platelets was determined.Inotropic effects and bp were measured via an indwelling catheter in anestetised cats after i.v. application of the test compounds. The inhibition of platelet PDEs was measured in freeze-thaw homogenates of human platelets using 3H-cAMP as substrate. Intraplatelet cAMP changes were measured by prelabelling the ATP pool with 3H-adenine and isolation of 3H-cAMP. Linear regression analysis of the drug concentrations causing a doubling of intraplatelet cAMP levis and the % difference in bp or the % difference in dp/dt, resp., by i.v. application of 0.3 mg/kg test compound yielded the following results:cAMP vs % diff. bp : r=0.02, N=18cAMP vs % diff. dp/dt: r = 0.02 , N = 15In contrast to a good correlation between intraplatelet cAMP levels and inhibition of platelet function tests, no obvious relationship was seen between cAMP and decrease in bp and positive initropic effects. It is not known whether the lack of correlation could be due to a different drug access to platelets and the bp regulatory system.A biochemical parameter, i.e. intraplatelet cAMP increase by inhibition of PDEs correlates reasonably well with the inhibition of platelet function tests. This parameter is not useful, however, to predict the effects on the heart and the circulatory system.

Standardization of platelet function tests

1981 ◽  
Vol 11 (2) ◽  
pp. 183-203 ◽  
Author(s):  
Pamela R. Roper-Drewinko ◽  
Benjamin Drewinko ◽  
Gail Corrigan ◽  
Dennis Johnston ◽  
Kenneth B. McCredie ◽  
...  
Keyword(s):  
Platelet Function ◽  
Platelet Function Tests ◽  
Function Tests

Platelet function tests during major operation for gastro-intestinal carcinoma

1977 ◽  
Vol 64 (2) ◽  
pp. 147-149 ◽  
Author(s):  
J. A. Kokores ◽  
T. C. Economopoulos ◽  
C. Alexopoulos ◽  
J. Pyrovolakis ◽  
A. G. Papayannis
Keyword(s):  
Platelet Function ◽  
Platelet Function Tests ◽  
Function Tests ◽  
Major Operation
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