Are P2Y12 reaction unit (PRU) and % inhibition index equivalent for the expression of P2Y12 inhibition by the VerifyNow® assay? Role of haematocrit and haemoglobin levels

2011 ◽  
Vol 106 (08) ◽  
pp. 227-229 ◽  
Author(s):  
Sophie Voisin ◽  
Vanina Bongard ◽  
Mohammed A. Tidjane ◽  
Thibault Lhermusier ◽  
Didier Carrié ◽  
...  

SummaryThe results of the whole blood VerifyNow® P2Y12 assay can be expressed as platelet reaction units (PRU) or % inhibition index (%inh), but an optimal cut-off for the assessment of high on-treatment platelet reactivity (HPR) predictive of clinical events has been validated only for PRU. The aim of the study was to study the influence of haematological variables, such as platelet and leukocyte counts or haematocrit / haemoglobin, within the limits indicated by the manufacturer for assay validity, on the results of the test. We performed a comparison of PRU and %inh in a series 186 samples obtained from a clinical trial on patients under dual antiplatelet therapy. The results show that PRU significantly decreases with increasing haematocrit / haemoglobin, whereas %inh does not, due to a parallel change in PRU and iso-TRAP baseline value. PRU and % inhibition index are not equivalent for the definition of HPR, because of their different sensitivities to haematocrit / haemoglobin.

2019 ◽  
Vol 51 (3) ◽  
pp. 310-314
Author(s):  
Moon Joo Kim ◽  
Pragna Patel ◽  
Niti Vyas ◽  
Christopher Leveque ◽  
Orlando Diaz ◽  
...  

Abstract A 70-year-old female with a history of hypertension and left A2 segment aneurysm was scheduled for pipeline embolization device (PED) placement. Preinterventional antiplatelet prophylaxis included aspirin and ticagrelor. Unexpectedly, after 13 days of treatment, VerifyNow showed a P2Y12 reaction unit (PRU) value of 216, approximately >5 times the mean PRU of other patients on aspirin and ticagrelor. We confirmed platelet reactivity and ticagrelor resistance with light transmission aggregometry. Antiplatelet therapy was switched to prasugrel, and aspirin was continued. Eight days later, the P2Y12 reaction value (PRU) was 164. PED was placed without complications. Unlike clopidogrel, ticagrelor is a direct P2Y12 inhibitor that does not require metabolism to an active metabolite. Ticagrelor resistance is very rarely reported. To the best of our knowledge, there has been no case of ticagrelor resistance reported in the context of pre-PED placement prophylaxis.


Author(s):  
Dian Hasiannami Boru Munthe ◽  
Siti Sjamsiah Sargo ◽  
Mohammad Yogiarto

AbstractBackgroundAntiplatelet agents used in coronary heart disease (CHD) cause gastrointestinal side effects. Omeprazole can prevent and cure these antiplatelet side effects. Clopidogrel combined with aspirin increases the risk of gastrointestinal tract ulcers and bleeding. This research studied the effect of omeprazole on the antiplatelet effect of clopidogrel.MethodsCHD patients using clopidogrel and aspirin receive omeprazole 20 mg in a single dose for 10 days. Platelet antiaggregation point for clopidogrel was measured using VerifyNow P2Y12. The cutoff points used were: low on treatment platelet reactivity (LPR) <85 P2Y12 reaction unit (PRU), normal on treatment platelet reactivity (NPR) 85–208 PRU, and high on treatment platelet reactivity (HPR) >208 PRU.ResultsUsing the paired t-test PRU points pre- and post-omeprazole were 154 ± 85.89 PRU and 169.4 ± 56.15 PRU, respectively. The PRU points were consistent or decreased from the previous PRU points below the HPR cutoff (p: 0.215; >0.05). Before omeprazole use, five patients were categorized as NPR, two patients as LPR, and three patients as HPR. After omeprazole use, two patients, each from HPR and NPR category had a PRU point >208; the rest showed results below the HPR point.ConclusionsIn this study the PRU points of clopidogrel after omeprazole use showed a PRU <208. The hypothesis that omeprazole may reduce the antiaggregation effect of clopidogrel as shown by the increase in PRU above the cutoff points >208 PRU (HPR) was not proven.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Fabiana Rollini ◽  
Jung Rae Cho ◽  
Francesco Franchi ◽  
Mona Bhatti ◽  
Christopher DeGroat ◽  
...  

Background: Clopidogrel is characterized by non-uniform pharmacodynamic (PD) effects leading to considerable rates of high on-treatment platelet reactivity (HPR), a marker of increased atherothrombotic risk. Prasugrel and ticagrelor have greater potency and more uniform PD effects compared with clopidogrel. The effects of switching from clopidogrel to prasugrel or ticagrelor and how this impacts HPR rates has been poorly explored. Methods: This was a prospective, randomized PD study conducted in patients with coronary artery disease on maintenance aspirin (81mg/qd) and clopidogrel (75mg/qd) therapy. Patients were randomized to switch to prasugrel (60mg loading dose/10mg maintenance dose qd) or ticagrelor (180mg loading dose/90mg maintenance dose bid) for 1 week. PD assessments were performed at 5 time points: before (while on clopidogrel) and 30 min, 2 hrs, 24 hrs and 1 week after switch. HPR was defined by a platelet reactivity index (PRI) > 50% assessed by VASP and platelet reaction unit (PRU) > 208 assessed by VerifyNow P2Y12 (VN). Results: A total of 110 patients were studied. HPR on clopidogrel therapy as defined by VASP-PRI was observed in 67.3% of the overall population. HPR rates were similarly distributed among patients subsequently randomized to prasugrel vs ticagrelor (69.8% vs 64.7%, p=0.57). After switching to prasugrel or ticagrelor, HPR rates significantly reduced as early as 30 min and continued to decrease consistently in both groups over the study time period. At 1 week, HPR was found in 13.7% and 15.6% of patients randomized to prasugrel and ticagrelor, respectively (p=0.80) (Figure). Parallel findings were observed when assessing HPR rates defined by VN-PRU (Figure). Conclusions: Switching from clopidogrel to a more potent P2Y 12 inhibiting agent significantly reduces HPR rates. Reduction in HPR rates occur to a similar extent between prasugrel and ticagrelor in both the acute and maintenance phases of therapy.


2017 ◽  
Vol 12 (3) ◽  
pp. 321-325 ◽  
Author(s):  
Yilong Wang ◽  
Yi Lin ◽  
Xia Meng ◽  
Weiqi Chen ◽  
Guohua Chen ◽  
...  

Rationale and aim Little is known about the safety and efficacy of the combination of ticagrelor and aspirin in acute ischemic stroke. This study aimed to evaluate whether the combination of ticagrelor and aspirin was superior to that of clopidogrel and aspirin in reducing the 90-day high on-treatment platelet reactivity for acute minor stroke or transient ischemic attack, especially for carriers of cytochrome P450 2C19 loss-of-function allele. Sample size and design This study was designed as a prospective, multicenter, randomized, open-label, active-controlled, and blind-endpoint, phase II b trial. The required sample size was 952 patients. It was registered with ClinicalTrials.gov (NCT02506140). Study outcomes The primary outcome was the proportion of patients with high on-treatment platelet reactivity at 90 days. High on-treatment platelet reactivity is defined as the P2Y12 reaction unit >208 measured using the VerifyNow P2Y12 assay. Conclusion The Platelet Reactivity in Acute Non-disabling Cerebrovascular Events study explored whether ticagrelor combined with aspirin could reduce further the proportion of patients with high on-treatment platelet reactivity at 90 days after acute minor stroke or transient ischemic attack compared with clopidogrel and aspirin.


2017 ◽  
Vol 225 (3) ◽  
pp. 189-199 ◽  
Author(s):  
Tina B. Lonsdorf ◽  
Jan Richter

Abstract. As the criticism of the definition of the phenotype (i.e., clinical diagnosis) represents the major focus of the Research Domain Criteria (RDoC) initiative, it is somewhat surprising that discussions have not yet focused more on specific conceptual and procedural considerations of the suggested RDoC constructs, sub-constructs, and associated paradigms. We argue that we need more precise thinking as well as a conceptual and methodological discussion of RDoC domains and constructs, their interrelationships as well as their experimental operationalization and nomenclature. The present work is intended to start such a debate using fear conditioning as an example. Thereby, we aim to provide thought-provoking impulses on the role of fear conditioning in the age of RDoC as well as conceptual and methodological considerations and suggestions to guide RDoC-based fear conditioning research in the future.


2014 ◽  
pp. 79-130 ◽  
Author(s):  
Ales Novak

The term ?business model' has recently attracted increased attention in the context of financial reporting and was formally introduced into the IFRS literature when IFRS 9 Financial Instruments was published in November 2009. However, IFRS 9 did not fully define the term ‘business model'. Furthermore, the literature on business models is quite diverse. It has been conducted in largely isolated fashion; therefore, no generally accepted definition of ?business model' has emerged. Therefore, a better understanding of the notion itself should be developed before further investigating its potential role within financial reporting. The aim of this paper is to highlight some of the perceived key themes and to identify other bases for grouping/organizing the literature based on business models. The contributions this paper makes to the literature are twofold: first, it complements previous review papers on business models; second, it contains a clear position on the distinction between the notions of the business model and strategy, which many authors identify as a key element in better explaining and communicating the notion of the business model. In this author's opinion, the term ‘strategy' is a dynamic and forward-looking notion, a sort of directional roadmap for future courses of action, whereas, ‘business model' is a more static notion, reflecting the conceptualisation of the company's underlying core business logic. The conclusion contains the author's thoughts on the role of the business model in financial reporting.


Sains Insani ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 10-14
Author(s):  
Ira Meilita Ibrahim ◽  
Taufik A. Latif ◽  
Afi Roshezry Abu Bakar ◽  
Muthualagan Thangavelu

The advancement of European dress to the rest of the world was linked to the definition of civilization as “a stage of social development considered to be more advanced” and “polite and good-mannered”. The widespread of their fashion style in the 19th and 20th centuries influenced the way the rest of the world attire. The fashion trend and dressing style thus change the purpose of dressing through time. The dressing style in campuses especially in private institutions of higher learning is under particular scrutiny, as it is often said to be inappropriate for a learning environment. This study looked at the importance of moral education, and its role in implementing the dress code for students among university students especially between two types of university i.e. public university and private university. It looked on the dressing style of students, both male and female, and the factors that lead to their dressing pattern which is common among students. This study also advocated the students’ understanding of the content of dress codes in their learning institution and the role played by moral education in regard to dress code. The overall study highlighted students’ perception towards the implementation of the dress code and punishment in their learning institution. The methodologies used to carry out this study are questionnaires and interviews. This study will therefore ascertain the important of dress code among students at higher learning institution and the role of moral education in cultivating values in order to dress properly or decently. Key Words: moral education, dress code, higher learning institution, civilization.


2020 ◽  
Vol 17 (5) ◽  
pp. 462-476
Author(s):  
Alexander A. Ushkarev ◽  
Galina G. Gedovius ◽  
Tatyana V. Petrushina

The technological revolution of recent decades has already brought art to the broadest masses, and the unexpected intervention of the pandemic has significantly accelerated the process of migration of theatrical art to the virtual space, causing the corresponding dynamics of the audience. What is the theater audience in the era of digitalization and the spread of alternative forms of cultural consumption? How does the theater build its relationship with the audience today? In search of answers, we conducted a series of sociological surveys of the Chekhov Moscow Art Theater’s audience — both at the theater’s performances and in the online community of its fans. The purpose of this phase of the study was to answer the fundamental questions: do spectators surveyed in the theater and those surveyed online represent the same audience; what are their main differences; and what are the drivers of their spectator behavior? The article presents the main results of a comparative analysis of two images of the Moscow Art Theatre’s audience based on a number of content parameters by two types of surveys, as well as the results of a regression analysis of the theater attendance. The study resulted in definition of the qualitative and behavioral differences between the theater visitors and the viewers surveyed online, and identification of the factors of theater attendance for both of the represented audience groups. The study made it possible to clarify the role of age and other socio-demographic parameters in cultural activity, as well as the influence of preferred forms of cultural consumption (live contacts or online views) on one’s attitude to art, motivation and spectator behavior. The conclusions of the study, despite the uniqueness of the object, reflect the general patterns of the modern art audience’s dynamics.


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