Comparison of light transmission aggregometry and multiple electrode aggregometry for the evaluation of patients with mucocutaneous bleeding

Classic Light Transmission Platelet Aggregometry: Do We Still Need it?

For more than 50 years, light transmission aggregometry has been accepted as the gold standard test for diagnosing inherited platelet disorders in platelet-rich plasma, although there are other functional approaches performed in whole blood. In this article, several advantages and disadvantages of this technique over other laboratory approaches are discussed in the view of recent guidelines, and the necessity of functional assays, such as light transmission aggregometry in the era of molecular genetic testing, is highlighted.

The study of platelet aggregation using a microtiter plate reader ‒ methodological considerations

Optical aggregometry by 96-well plate assay, the microplate method, is a fast, efficient, and readily available method for measuring the pharmacological effects of antiplatelet drugs. Even though recent years have witnessed growing interest in adopting the microplate method for widespread use, it remains in the shadow of the standard light transmission aggregometry (LTA). Regardless of the method used, the results of platelet aggregation depend on a variety of factors and often vary among laboratories worldwide. While several methodological papers have examined the microplate method, no standards have been established, most likely because the approach is not used as a diagnostic tool. Currently, the microplate method is recommended by researchers to be used in conjunction with LTA or as an adjunct to LTA. This raises the question of whether an optimal protocol exists for microplate aggregometry, and what are the key considerations in a good experimental protocol for obtaining reliable results? This article attempts to address these questions by summarizing the knowledge accumulated in this field over the last three decades.

Factors that modulate platelet reactivity as measured by 5 assay platforms in 3429 individuals

Background

Assessment of platelet function is key in diagnosing bleeding disorders and evaluating antiplatelet drug efficacy. However, there is a prevailing "one-size-fits-all" approach in the interpretation of measures of platelet reactivity, with arbitrary cutoffs often derived from healthy volunteer responses.

Objectives

Our aim was to compare well-used platelet reactivity assays.

Methods

Blood and platelet-rich plasma obtained from the Framingham Heart Study (N = 3429) were assayed using a range of agonists in 5 platelet assays: light transmission aggregometry, Optimul aggregometry, Multiplate impedance aggregometry (Roche Diagnostics), Total Thrombus-Formation Analysis System, and flow cytometry. Using linear mixed-effect models, we determined the contribution of preanalytical and technical factors that modulated platelet reactivity traits.

Results

A strong intra-assay correlation of platelet traits was seen in all assays, particularly Multiplate velocity (r = 0.740; ristocetin vs arachidonic acid). In contrast, only moderate interassay correlations were observed (r = 0.375; adenosine diphosphate Optimul Emax vs light transmission aggregometry large area under the curve). As expected, antiplatelet drugs strongly reduced platelet responses, with aspirin use primarily targeting arachidonic acid-induced aggregation, and explained substantial variance (β = -1.735; P = 4.59 × 10-780; variance proportion = 46.2%) and P2Y12 antagonists blocking adenosine diphosphate responses (β = -1.612; P = 6.75 × 10-27; variance proportion = 2.1%). Notably, female sex and older age were associated with enhanced platelet reactivity. Fasting status and deviations from standard venipuncture practices did not alter platelet reactivity significantly. Finally, the agonist batch, phlebotomist, and assay technician (more so for assays that require additional sample manipulation) had a moderate to large effect on measured platelet reactivity.

Conclusion

Caution must be exercised when extrapolating findings between assays, and the use of standard ranges must be medication-specific and sex-specific at a minimum. Researchers should also consider preanalytical and technical variables when designing experiments and interpreting platelet reactivity measures.

Platelet function in neonates and children

Platelets are major regulators of haemostasis and coagulation. The primary role of platelets in coagulation is to form a stable clot and stop bleeding. Studies of platelet phenotype and function in neonates and children have been restricted by the large volumes required for many common platelet function tests such as platelet aggregometry. Developmental changes in platelets have not been as well described as developmental changes in plasma coagulation proteins, and overall, platelet phenotype and function in neonates and children has been understudied when compared to adults. Recent developments in more sensitive platelet function testing methods requiring smaller blood volumes such as flow cytometry has enabled recent studies to further investigate platelet phenotype and function in neonates and children. In this review we will provide an overview of recent advances from the past five years in platelets in the context of developmental haemostasis, as well as the role of platelets in neonatal paediatric disease.

Platelet aggregation in Klinefelter syndrome is not aggravated by testosterone replacement therapy: A longitudinal follow-up study

BACKGROUND

Men with Klinefelter syndrome (KS) are routinely offered testosterone replacement therapy (TRT) suggested to potentially promote platelet aggregation and increase cardiovascular risk.

OBJECTIVE

We investigated platelet aggregation in men with KS before and during TRT.

MATERIALS AND METHODS

Forty-one adult men with KS participated, of which 20 had no history of TRT at baseline, with 15 completing follow-up after 18 months TRT. Further, we included 21 adult men with KS on long-term TRT (>10 years) and a male reference population. We assessed platelet impedance aggregometry using adenosine diphosphate (6.5 μM), thrombin-receptor-activating-peptide-6 (TRAP 32 μM), and arachidonic acid (ASPI 0.5 mM) as agonists in KS compared to a male reference population and stratified by route of TRT administration.

RESULTS

Platelet aggregation among men with KS at baseline or during TRT was not increased compared with the male reference population. For all three agonist, no change was seen in platelet aggregation in KS at follow-up compared with baseline (p ≥ 0.2). Platelet aggregation was not associated with total testosterone and furthermore, platelet count was not affected by treatment with testosterone. Men with KS treated with testosterone gel showed slightly increased TRAP- and ASPI-induced platelet aggregation compared with those treated with testosterone injection (p = 0.02 and p = 0.04, respectively).

DISCUSSION AND CONCLUSIONS

We observed normal platelet aggregation in men with KS before TRT and following both short and long term treatment. Our findings do not support an independent role of platelets in driving the cardiovascular risk in KS.

Aspirin Resistance in Vascular Disease: A Review Highlighting the Critical Need for Improved Point-of-Care Testing and Personalized Therapy

Aspirin resistance describes a phenomenon where patients receiving aspirin therapy do not respond favorably to treatment, and is categorized by continued incidence of adverse cardiovascular events and/or the lack of reduced platelet reactivity. Studies demonstrate that one in four patients with vascular disease are resistant to aspirin therapy, placing them at an almost four-fold increased risk of major adverse limb and adverse cardiovascular events. Despite the increased cardiovascular risk incurred by aspirin resistant patients, strategies to diagnose or overcome this resistance are yet to be clinically validated and integrated. Currently, five unique laboratory assays have shown promise for aspirin resistance testing: Light transmission aggregometry, Platelet Function Analyzer-100, Thromboelastography, Verify Now, and Platelet Works. Newer antiplatelet therapies such as Plavix and Ticagrelor have been tested as an alternative to overcome aspirin resistance (used both in combination with aspirin and alone) but have not proven to be superior to aspirin alone. A recent breakthrough discovery has demonstrated that rivaroxaban, an anticoagulant which functions by inhibiting active Factor X when taken in combination with aspirin, improves outcomes in patients with vascular disease. Current studies are determining how this new regime may benefit those who are considered aspirin resistant.

PLATELET FUNCTION IN TRAUMA: IS CURRENT TECHNOLOGY IN FUNCTION TESTING MISSING THE MARK IN INJURED PATIENTS?

ABSTRACT

Platelets are subcellular anucleate components of blood primarily responsible for initiating and maintaining hemostasis. After injury to a blood vessel, platelets can be activated via several pathways, resulting in changed shape, adherence to the injury site, aggregation to form a plug, degranulation to initiate activation in other nearby platelets, and acceleration of thrombin formation to convert fibrinogen to fibrin before contracting to strengthen the clot. Platelet function assays use agonists to induce and measure one or more of these processes to identify alterations in platelet function that increase the likelihood of bleeding or thrombotic events. In severe trauma, these assays have revealed that platelet dysfunction is strongly associated with poor clinical outcomes. However, to date, the mechanism(s) causing clinically significant platelet dysfunction remain poorly understood. We review the pros, cons, and evidence for use of many of the popular assays in trauma, discuss limitations of their use in this patient population, and present approaches that can be taken to develop improved functional assays capable of elucidating mechanisms of trauma-induced platelet dysfunction. Platelet dysfunction in trauma has been associated with need for transfusions and mortality; however, most of the current platelet function assays were not designed for evaluating trauma patients, and there are limited data regarding their use in this population. New or improved functional assays will help define the mechanisms by which platelet dysfunction occurs, as well as help optimize future treatment.

Advances in the diagnosis of heritable platelet disorders

The last decade has seen large increases in the number of patients registered with heritable platelet disorders in national databases of bleeding disorders. Although individually rare, collectively they are a relatively common cause of heritable bleeding. This revolution has come about through the application of high-throughput sequencing strategies and efforts to standardize diagnostic testing. There is renewed interest in established parameters such as platelet volume and utilising simple tools such as blood smears. The diagnostic yield from peripheral blood smears can be improved with new microscopy techniques that could potentially assist in determining which patients need to be referred to tertiary centres for specialist testing. A better understanding of the other clinical features that can accompany abnormalities of platelet number or function, can lead to better clinical management and prevention of serious complications. There are challenges for clinicians who need to be aware of these developments, understand the limitations of new diagnostic techniques and keep abreast of strategies for incorporation into clinical practice. This review discusses some of these approaches, the limitations that clinicians need to be aware of and techniques that may enter clinical use in the future.

Screening and diagnosis of inherited platelet disorders

Inherited platelet disorders are important conditions that often manifest with bleeding. These disorders have heterogeneous underlying pathologies. Some are syndromic disorders with non-blood phenotypic features, and others are associated with an increased predisposition to developing myelodysplasia and leukemia. Platelet disorders can present with thrombocytopenia, defects in platelet function, or both. As the underlying pathogenesis of inherited thrombocytopenias and platelet function disorders are quite diverse, their evaluation requires a thorough clinical assessment and specialized diagnostic tests, that often challenge diagnostic laboratories. At present, many of the commonly encountered, non-syndromic platelet disorders do not have a defined molecular cause. Nonetheless, significant progress has been made over the past few decades to improve the diagnostic evaluation of inherited platelet disorders, from the assessment of the bleeding history to improved standardization of light transmission aggregometry, which remains a "gold standard" test of platelet function. Some platelet disorder test findings are highly predictive of a bleeding disorder and some show association to symptoms of prolonged bleeding, surgical bleeding, and wound healing problems. Multiple assays can be required to diagnose common and rare platelet disorders, each requiring control of preanalytical, analytical, and post-analytical variables. The laboratory investigations of platelet disorders include evaluations of platelet counts, size, and morphology by light microscopy; assessments for aggregation defects; tests for dense granule deficiency; analyses of granule constituents and their release; platelet protein analysis by immunofluorescent staining or flow cytometry; tests of platelet procoagulant function; evaluations of platelet ultrastructure; high-throughput sequencing and other molecular diagnostic tests. The focus of this article is to review current methods for the diagnostic assessment of platelet function, with a focus on contemporary, best diagnostic laboratory practices, and relationships between clinical and laboratory findings.

Platelet function and filamin A expression in two families with novel FLNA gene mutations associated with periventricular nodular heterotopia and panlobular emphysema

Pathogenic variants of the X‐linked FLNA gene encoding filamin A protein have been associated with a wide spectrum of symptoms, including the recently described pulmonary phenotype with childhood‐onset panlobular emphysema. We describe three female patients from two families with novel heterozygous FLNA variants c.5837_2del and c.508C > T. Analysis of immunofluorescence of peripheral blood smears and platelet function was performed for all patients. FLNA‐negative platelets were observed, suggesting that these variants result in the loss of a functional protein product. All three patients also had periventricular nodular heterotopia and panlobular emphysema. However, they had considerably milder symptoms and later age of onset than in the previously reported cases. Therefore, patients with pathogenic FLNA variants should be studied actively for lung involvement even in the absence of pronounced respiratory symptoms. Conversely, any patient with unexplained panlobular emphysema should be analyzed for pathogenic FLNA variants. We also suggest that immunofluorescence analysis is a useful tool for investigating the pathogenicity of novel FLNA variants.

Performance comparison of the PFA-200 and Anysis-200: Assessment of bleeding risk screening in cardiology patients

BACKGROUND

Assessment of platelet function is important in the management of patients who are subject to operation as well as at potential risk of hemorrhagic complications.

OBJECTIVE

This study aimed to evaluate a new platelet assays (Anysis-Epinephrine, Anysis-ADP) and to compare them with PFA-200 in cardiology visiting patients and inpatients.

METHODS

Citrated blood samples were collected from 184 patients for ADP test and 163 patients for EPI test, who visited Korea University Guro Hospital with written consent. The PFA-200 assay gives a test result the closure time (CT) until the blood flow rate decreases to 10%of the initial value, whereas Anysis-200 assay does a blood flow migration distance (MD) until blood flow completely stops. According to the results of PFA closure time (CT), the tested samples were classified as either negative control or positive group. The measurements were simultaneously conducted with two devices and compared.

RESULTS

The sensitivity and specificity of Anysis-200 C/EPI kit in comparison to PFA-200 C/EPI kit was 87.5%and 85.7%, respectively. Regarding C/ADP kit, the sensitivity and specificity of Anysis-200 was 96.9%and 87.5%, respectively. In addition, the sums of sensitivity and specificity are greater than 150%for both of EPI and ADP. Also, it was found that likelihood ratio and odd ratio for each assay provide useful additional information. Since the Cohen's kappa coefficients value between the two devices was relatively high, the equivalence between the two devices was confirmed.

CONCLUSIONS

Anysis-200, a novel platelet function analyzer has showed excellent agreements with PFA-200 with high agreement rates and precision. Anysis-200 assay would be useful in assessing bleeding risk management as well as abnormal platelet reactivity at point of care.

Plateletworks® as a Point-of-Care Test for ASA Non-Sensitivity

Aspirin (ASA) therapy is proven to be effective in preventing adverse cardiovascular events; however, up to 30% of patients are non-sensitive to their prescribed ASA dosage. In this pilot study, we demonstrated, for the first time, how ASA non-sensitivity can be diagnosed using Plateletworks®, a point-of-care platelet function test. Patients prescribed 81 mg of ASA were recruited in a series of two successive phases-a discovery phase and a validation phase. In the discovery phase, a total of 60 patients were recruited to establish a cut-off point (COP) for ASA non-sensitivity using Plateletworks®. Each sample was simultaneously cross-referenced with a light transmission aggregometer (LTA). Our findings demonstrated that >52% maximal platelet aggregation using Plateletworks® had a sensitivity, specificity, and likelihood ratio of 80%, 70%, and 2.67, respectively, in predicting ASA non-sensitivity. This COP was validated in a secondary cohort of 40 patients prescribed 81 mg of ASA using Plateletworks® and LTA. Our data demonstrated that our established COP had a 91% sensitivity and 69% specificity in identifying ASA non-sensitivity using Plateletworks®. In summary, Plateletworks® is a point-of-care platelet function test that can appropriately diagnose ASA non-sensitive patients with a sensitivity exceeding 80%.

Platelet function assays for the diagnosis of aspirin resistance

Aspirin, an antiplatelet drug, is commonly used at low doses for numerous indications, including prophylaxis of cardiovascular, neurovascular, and venous thromboembolic events. Due to review articles suggesting that aspirin resistance may result in poorer outcomes, interest in assessing platelet function is increasing. Despite this, platelet function tests are rarely used as part of routine clinical practice and therefore, a basic understanding of these tests may be lacking. Although aspirin resistance can be categorized as clinical or laboratory resistance, determining laboratory resistance is the only way to determine resistance before treatment failure occurs. Therefore, knowledge of platelet assays to determine aspirin resistance is of importance. The following review aims to provide a framework for clinicians to understand the main principles of platelet function tests. This includes comparison of the most frequently used platelet assays to diagnose aspirin resistance, including the basic mechanism, methodology, reference ranges, inter-assay comparison, and their respective clinical considerations when using.

The Current Role of Platelet Function Testing in Clinical Practice

Platelet dysfunction, whether hereditary or acquired, may increase an individual's risk of spontaneous, posttraumatic, or postoperative bleeding. Conversely, increased platelet reactivity on antiplatelet agents following vascular (in particular, coronary vascular) intervention may increase the risk of thrombosis and adverse vascular events. The aim of platelet function testing is to identify and characterize platelet dysfunction in these settings to inform bleeding/ thrombosis risk and guide perioperative prophylactic management strategies. A vast array of screening and diagnostic tests is available for this purpose. The successful clinical application of platelet function tests depends on the knowledge of their analytical strengths and limitations and the correct extrapolation of derived results to a particular clinical scenario. This review critically appraises traditional and contemporary platelet function testing focusing on their role in clinical practice.

Relation Between Platelet Reactivity Levels and Diabetic Retinopathy Stage in Patient with Type 2 Diabetes Mellitus by Using Multiplate Whole Blood Aggregometry

Purpose: To test the hypothesis of a possible association between platelet reactivity and the severity of diabetic retinopathy using Multiplate whole blood aggregometry in type 2 diabetes mellitus patients. Methods: Of 157 patients were divided to three groups based on the severity of diabetic retinopathy (normal, non-proliferative and proliferative [ordinal among group 1-2-3]). Platelet reactivity was measured using arachidonic acid response to the ASPI and ADP platelet test. The association between DR stage and the degree of platelet reactivity (predictor variable) ASPI, ADP, systolic blood pressure, age, hypertension, body mass index (BMI), HbA1c, creatinine, Microalbumin, platelet, triglyceride/HDL and Hscrp variables were evaluated using ordinal logistic regression models (Model 1). The association between DR presence (outcome variable (group 1 vs group 2 and 3)) and the presence of variables was evaluated using binary logistic regression models (Model 2). Results: A comparison of the laboratory parameters of the three groups revealed that the ASPI, ADP, glucose and HbA1c values were significantly higher in Group-3 than Group-1. ASPI (odds-ratio OR: 1.044[1.021-1.09], p < .001], ADP (OR: 1.033[1.010-1.10], p: 0.002] and HbA1c (OR: 2.42(1.22, 4.94), p < .001) were demonstrated to be associated with stage of DR while the other variables were not. In binary logistic regression (model-2) analysis; ASPI (OR: 1.061[1.031-1.1], p < .001], ADP (OR: 1.03(1.01, 1.06), p: 0.045] and HbA1c (OR: 4.37 (1.67, 11.36)], p: 0.002) were associated with DR while the other variables were not. Conclusion: Herewith, we demonstrated that higher platelet reactivity measured by multiplate ASPI and ADP was significantly associated with stages of DR. Therefore, these measurements may be useful to predict the severity of DR in the clinical practice of physicians.

Cardiopulmonary bypass-induced coagulopathy in pediatric patients: The role of platelets in postoperative bleeding. A preliminary study

Pediatric patients are particularly prone to cardiopulmonary bypass (CPB)-induced coagulopathy mainly due to hemodilution, consumption of coagulation factors and hypothermia. The aim of the present study was to examine the possible role of platelet count and function as it relates to the bleeding risk after CPB in the pediatric population. All consecutive patients (age <13 years) scheduled for elective cardiac surgery between January 2019 and November 2019 were retrospectively considered for the study. We gathered demographic characteristics, perioperative laboratory data (mainly platelet count and function), transfusion requirements, and blood loss for each patient. Patients with a chest tube output during the first 24 hours after surgery >75th percentile were bleeders (cases). Controls were nonbleeders. A total of 31 patients were enrolled [median age 17 (4-57) months]. A significant postoperative reduction in platelet count (P < .001) and function either in ADP-test (P < .001), TRAP-test (P < .001) and ASPI-test (P < .001) was found, with positive correlations between chest tube output within the first 24 hours after surgery and postoperative impairment of platelet count (R = 0.553, P = .001), ADP-test (R = 0.543, P = .001), TRAP-test (R = 0.627, P < .001) and ASPI-test (R = 0.436, P = .014). Eight children (26%) experienced major postoperative bleeding. Bleeders were significantly younger (P = .015) and underwent longer CPB duration (P = .015). Despite no significant differences in postoperative platelet count and function between cases and controls, the postoperative reduction (Δ) in platelet count (P = .002) and function in ADP-test (P = .007), TRAP-test (P = .020) and ASPI-test (P = .042) was significantly greater in bleeders vs. nonbleeders. A ΔPLT >262 500 ×10⁹ /L, a ΔADP-test >29 U, a ΔTRAP-test >44 U and a ΔASPI-test >26 U showed to be predictive of major postoperative bleeding. Postoperative bleeding in children undergoing cardiac surgery with CPB was linked to younger age, longer CPB duration, and significant postoperative reduction in platelet count and function. Larger studies are needed to confirm our results and define strategies to reduce postoperative bleeding in these patients.

Platelet Dysfunction after Traumatic Brain Injury: A Review

Coagulopathy is a known sequela of traumatic brain injury (TBI) and can lead to increased morbidity and mortality. Platelet dysfunction has been identified as one of several etiologies of coagulopathy following TBI and has been associated with poor outcomes. Regardless of whether the platelet dysfunction occurs as a direct consequence of the injury or because of pre-existing medical comorbidities or medication use, accurate detection and monitoring of response to therapy is key to optimal patient care. Platelet transfusion has been proposed as a potential therapeutic intervention to treat platelet dysfunction, with several studies using platelet function assays to monitor response. The development of increasingly precise diagnostic testing is providing enhanced understanding of the specific derangement in the hemostatic process, allowing clinicians to provide patient-specific treatment plans. There is wide variability in the currently available literature on the incidence and clinical significance of platelet dysfunction following TBI, which creates challenges with developing evidence-based management guidelines. The relatively high prevalence of platelet inhibitor therapy serves as an additional confounding factor. In addition, the data are largely retrospective in nature. We performed a literature review to provide clarity on this clinical issue. We reviewed 348 abstracts, and included 97 manuscripts in our final literature review. Based on the currently available research, platelet dysfunction has been consistently demonstrated in patients with moderate-severe TBI. We recommend the use of platelet functional assays to evaluate patients with TBI. Platelet transfusion directed at platelet dysfunction may lead to improved clinical outcome. A randomized trial guided by implementation science could improve the applicability of these practices.

Advances in Platelet Function Testing-Light Transmission Aggregometry and Beyond

Platelet function testing is essential for the diagnosis of hemostasis disorders. While there are many methods used to test platelet function for research purposes, standardization is often lacking, limiting their use in clinical practice. Light transmission aggregometry has been the gold standard for over 60 years, with inherent challenges of working with live dynamic cells in specialized laboratories with independent protocols. In recent years, standardization efforts have brought forward fully automated systems that could lead to more widespread use. Additionally, new technical approaches appear promising for the future of specialized hematology laboratories. This review presents developments in platelet function testing for clinical applications.

Updates in diagnosis of the inherited platelet disorders

PURPOSE OF REVIEW

To provide a comprehensive update on the current available methodologies and techniques for diagnosis of inherited platelet disorders (IPD).

RECENT FINDINGS

The contributions of many groups have resulted in the significant progress in the molecular diagnosis of IPD including the identification of many genes responsible for the various phenotypes. The widespread use and availability of next-generation sequencing has brought to the forefront ethical challenges associated with nontargeted sequencing as well as provided us with novel variants to functionally validate. These requirements have driven the development of novel tools for functional assessment of platelets, although none of the novel techniques beyond sequencing have yet taken clinical hold.

SUMMARY

Much work is ongoing on functional and molecular assessment of platelet disorders and the incorporation of combined assessments is likely to yield the highest diagnostic results.

The MICELI (MICrofluidic, ELectrical, Impedance): Prototyping a Point-of-Care Impedance Platelet Aggregometer

As key cellular elements of hemostasis, platelets represent a primary target for thrombosis and bleeding management. Currently, therapeutic manipulations of platelet function (antithrombotic drugs) and count (platelet transfusion) are performed with limited or no real-time monitoring of the desired outcome at the point-of-care. To address the need, we have designed and fabricated an easy-to-use, accurate, and portable impedance aggregometer called “MICELI” (MICrofluidic, ELectrical, Impedance). It improves on current platelet aggregation technology by decreasing footprint, assay complexity, and time to obtain results. The current study aimed to optimize the MICELI protocol; validate sensitivity to aggregation agonists and key blood parameters, i.e., platelet count and hematocrit; and verify the MICELI operational performance as compared to commercial impedance aggregometry. We demonstrated that the MICELI aggregometer could detect platelet aggregation in 250 μL of whole blood or platelet-rich plasma, stimulated by ADP, TRAP-6, collagen, epinephrine, and calcium ionophore. Using hirudin as blood anticoagulant allowed higher aggregation values. Aggregation values obtained by the MICELI strongly correlated with platelet count and were not affected by hematocrit. The operational performance comparison of the MICELI and the Multiplate^® Analyzer demonstrated strong correlation and similar interdonor distribution of aggregation values obtained between these devices. With the proven reliability of the data obtained by the MICELI aggregometer, it can be further translated into a point-of-care diagnostic device aimed at monitoring platelet function in order to guide pharmacological hemostasis management and platelet transfusions.