Study on related substances of TSD-1 — a novel P2Y12 receptor antagonist / 药学学报

For quantitative analysis of related substances in TSD-1 active pharmaceutical ingredient, structures of prepared impurities were confirmed by NMR and UHPLC-MS, and a high performance liquid chromatographic method was established to determine the related substances in TSD-1. The analytical column was an Agilent ZORBAX Eclipe XDB-C8 (250 mm × 4.6 mm, 5 µm). The mobile phase A was 50 mmol·L-1 ammonium acetate solution (adjusted pH to 5.8 with acetic acid) and the mobile phase B was acetonitrile. The whole run was carried out by gradient elution at a flow rate of 1.0 mL·min-1. The detection wavelength was set at 240 nm and the column temperature was 30 ℃. The resolutions among peaks of TSD-1, impurity A, impurity B, TSD-D, and TSD-F were good. The calibration curves (n = 7) of TSD-1, impurity A, impurity B, TSD-D and TSD-F were linear in their respective weight ranges of 0.242-48.4 µg·mL-1 (r = 1.000 0), 0.244-9.75 µg·mL-1 (r = 0.999 9), 0.244-4.80 µg·mL-1 (r = 0.999 9), 0.254-1.02 µg·mL-1 (r = 0.999 9), and 0.247-0.987 µg·mL-1 (r = 0.999 9). The lower limits of quantitation were 0.244, 0.244, 0.254, and 0.247 µg·mL-1 for impurity A, impurity B, TSD-D, and TSD-F, respectively, and the average recovery of each impurity ranged from 99.08% to 103.00% with high accuracy. TSD-D and TSD-F were not detected in the three batches of TSD-1 active pharmaceutical ingredients, and impurity A and impurity B were not detected beyond the limit. The established HPLC method is simple, accurate, and suitable for determination of related substances of TSD-1, which can provide a valuable reference for the subsequent development of TSD-1.

Opposite Modulatory Effects of Crataegus aronia Aqueous Extract on Platelet Aggregation in Rats / 中国结合医学杂志

OBJECTIVES@#To reveal the mechanisms behind the dual effects of Crataegus aronia (C. aronia) aqueous extract on platelet aggregation by focusing on function, regulation, expression, and signaling of platelets P@*METHODS@#Adult male Wistar rats (120 ± 10 g) were classified as control received the vehicle, C. aronia (200 mg/kg), and C. aronia (2,000 mg/kg)-treated rats. After treatments for consecutive 7 days, hematological and molecular experiments were conducted to detect alterations in platelet aggregation, thromboxane B2 (THXB2) and intracellular reactive oxygen species (ROS) content; protein levels of P@*RESULTS@#At a concentration of 200 mg/kg, C. aronia inhibited platelet aggregation through multiple interconnected mechanisms including downregulation P@*CONCLUSION@#Oral administration of C. aronia at low dose inhibits platelet aggregation by reducing THXB2 release, expression of P-selectin and activating cAMP and Akt signaling through two major mechanisms including downregulation of P

Asociación entre el volumen plaquetario medio y la resistencia a aspirina e inhibidores del receptor p2y12 en pacientes ancianos con síndrome coronario agudo / Association between Mean Platelet Volume and Resistance to Aspirin and P2Y12 Receptor Inhibitors in Elderly Patients with Acute Coronary Syndrome

RESUMEN Introducción: La resistencia a antiagregantes y el volumen plaquetario medio (VPM) son predictores de eventos en el síndrome coronario agudo (SCA). La asociación entre ambos ha sido poco estudiada. Objetivos: Evaluar si existe asociación entre la resistencia a la aspirina (AAS) e inhibidores del receptor P2Y12 (iP2Y12) y el VPM en pacientes mayores de 65 años con SCA. Material y métodos: Se incluyeron pacientes mayores de 65 años con diagnóstico de SCA. Se dividieron en: grupo 1 (resistencia a ambos antiagregantes), grupo 2 (a uno de los antiagregantes) y grupo 3 (a ningún antiagregante). Se midió la agregación plaquetaria entre las 12 y 24 horas poscarga (por light transmission aggregometry). Se consideró resistencia a iP2Y12 a un porcentaje máximo de agregación (PMA) con ADP > 60% y a la AAS a un PMA con ARA > 20%. En el seguimiento se consi-deró el punto final combinado de muerte global y reinternación cardiovascular. Resultados: Se incluyeron 195 pacientes que recibieron AAS e iP2y12 (120 recibieron clopidogrel y 75 ticagrelor); grupo 1 (19%), grupo 2 (34,4%) y grupo 3 (46,6%). El VPM se asoció a la resistencia a ambos antiagregantes (OR 1,02 (IC 95% 1,01-1,05), p = 0,03. A su vez, el VPM y el GRACE fueron predictores independientes del punto combinado (HR 1,03 (IC 95% 1,01-1,07), p = 0,04 y HR 1,02 (IC 95% 1,01-1,04), p = 0,02), respectivamente. Conclusiones: El VPM se asoció a la presencia de resistencia a ambos antiagregantes. En el seguimiento el VPM y el score GRACE fueron predictores del punto combinado.

ABSTRACT Background: Antiplatelet resistance and mean platelet volume (MPV) are event predictors in acute coronary syndrome (ACS). However, the association between both has been poorly studied. Objective: The aim of this study was to evaluate the association between MPV and resistance to aspirin (ASA) and P2Y12 receptor inhibitors (P2Y12i) in elderly patients with ACS. Methods: Patients over 65 years old with diagnosis of ACS were included in the study. They were divided into group 1 (re-sistance to both antiplatelet agents), group 2 (resistance to one antiplatelet agent) and group 3 (no resistance to antiplatelet agents). Platelet aggregation was measured between 12 and 24 hours postload (by light transmission aggregometry). Resis-tance to P2Y12i was considered as maximum percentage of aggregation (MPA) with adenosine diphosphate (ADP) >60% and resistance to ASA as MPA with arachidonic acid (ARA) >20%. The composite endpoint of global death and cardiovascular re-hospitalization was considered during follow-up. Results: One hundred and ninety five patients included in the study received ASA and P2Y12i (120 received clopidogrel and 75 ticagrelor). Nineteen percent of patients belonged to group 1, 34.4% to group 2 and 46.6% to group 3. Mean platelet volume was associated with resistance to both antiplatelet agents [OR 1.02 (95% CI 1.01-1.05), p=0.03], while MPV and the GRACE score were independent predictors of the composite endpoint [HR 1.03 (95% CI 1.01-1.07), p=0.04] and [HR 1.02 (95% CI 1.01-1.04), p=0.02], respectively. Conclusions: Mean platelet volume was associated with the presence of resistance to both antiplatelet agents. During follow-up, MPV and the GRACE score were predictors of the composite endpoint.

Evaluation of platelet activity by multiple electrode impedance aggregometry in acute coronary syndromes: pilot study in a Brazilian tertiary-care public hospital

There is no definite recommendation for testing platelet aggregation (PA) in acute coronary syndromes (ACS) due to inconclusive evidence on the usefulness of platelet function tests to guide therapy and improve clinical outcomes. The evaluation of PA with multiple electrode impedance platelet aggregometry (MEA) may be useful to manage antiplatelet therapy and possibly influence patient outcome. The primary aim of this study was to measure PA with MEA in Brazilian patients with ACS and evaluate the association between PA and adverse clinical outcomes. Forty-seven consecutive patients admitted with ACS to a Brazilian tertiary-care public hospital were studied and PA was evaluated using MEA. Patients were followed for six months for the occurrence of all-cause death, acute myocardial infarction, or stroke. Suboptimal inhibition of PA was found in 7 patients (14.9%); 5 (10.6%) in response to ASA (acetylsalicylic acid), 2 (5.0%) to clopidogrel, and none to ticagrelor. Inadequate PA inhibition in response to ASA was significantly associated with the composite end point, but there was no significant association for insufficient PA inhibition in response to clopidogrel. This study suggested that the evaluation of PA in ACS using MEA may identify non-responders to ASA. Larger studies are necessary to define, in a public health scenario, the value of MEA in the management of ACS.

Correlations of P2Y12 gene polymorphism with clopidogrel resistance and long -term outcome in patients with acute ischemic stroke / 国际脑血管病杂志

Objective To investigate the correlations of P2Y12 gene polymorphisms with clopidogrel resistance and long-term outcome in patients with acute ischemic stroke. Methods From June 2015 to June 2017, consecutive patients with acute ischemic stroke admitted to the Department of Neurology, Nanjing Jiangbei People's Hospital were enrolled. Thromboelastography was used to measure platelet inhibition rate and assess clopidogrel resistance. Polymerase chain reaction was used to assay C34T and G52T polymorphisms of P2Y12 gene. The patients were followed up at 12 months after discharge. The primary outcome was combined outcome of stroke recurrence, myocardial infarction, and death due to cardiocerebrovascular events. Results A total of 214 patients were enrolled, 51 (23.8%) had clopidogrel re-sistance and 29 (13.4%) had major outcome events. One hundred twenty-eight (59.8%) patients were C34T CC genotype and 86 (40.2%) were CT+TT genotype. The proportion of clopidogrel resistance in patients with CT+TT genotype was significantly higher than that with CC genotype ( 76.5% vs.28.8%;χ2=25.672, P=0.001). There were 131 patients (61.2%) with G52T GG genotype and 83 (38.8%) with GT+TT genotype. There was no significant difference in the proportion of clopidogrel resistance between the GT+TT genotype and the GG genotype (43.1% vs.37.4%; χ2=0.534, P=0.465). Multiple logistic regression analysis indicated that age (odds ratio [OR] 1.064, 95%confidence interval [CI] 1.009-1.115;P=0.021), diabetes ( OR 3.773, 95%CI 1.672-8.475; P=0.004), and C34T CT+TT genotype ( OR 9.087, 95%CI 4.416-22.665; P=0.002) were the independent risk factors fot clopidogrel resistance. Cox proportional hazards model analysis showed that age (Hazard ratio [HR] 1.058, 95%CI 1.001-1.121; P=0.049), hypertension ( HR 3.105, 95%CI 1.149-9.523; P=0.028), homocysteine ( HR 1.101, 95%CI 1.020-1.190; P=0.014), and C34T CT+TT genotype ( HR 2.588, 95%CI 1.121-5.967; P=0.026) were independent risk factors for the composite outcome. Conclusion C34T polymorphism of P2Y12 gene in patients with acute ischemic stroke may be a risk factor for clopidogrel resistance and is independently associated with the risk of long-term recurrence of vascular events.

De-Escalation of P2Y₁₂ Receptor Inhibitor Therapy after Acute Coronary Syndromes in Patients Undergoing Percutaneous Coronary Intervention

Dual antiplatelet therapy (DAPT) — a combination of a P2Y₁₂ receptor inhibitor and aspirin — has revolutionized antithrombotic treatment. Potent P2Y₁₂ inhibitors such as prasugrel and ticagrelor exhibit a strong and more consistent platelet inhibition when compared to clopidogrel. Therefore, ticagrelor and prasugrel significantly reduce ischemic events, but at an expense of an increased bleeding risk in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). These observations have engaged intensive clinical research in alternative DAPT regimens to achieve sufficient platelet inhibition with an acceptable bleeding risk. Our review focusses on P2Y₁₂ receptor therapy de-escalation defined as a switch from a potent antiplatelet agent (ticagrelor or prasugrel) to clopidogrel. Recently, both unguided (platelet function testing independent) and guided (platelet function testing dependent) DAPT de-escalation strategies have been investigated in different clinical studies and both switching strategies could be possible options to prevent bleeding complications without increasing ischemic risk. In light of the still limited data currently available, future large-scale trials should accumulate more data on various DAPT de-escalation regimens with both ticagrelor and prasugrel in unguided and guided de-escalation approaches. In the current review we aim at summarizing and discussing the current evidence on this still emerging topic in the field of antiplatelet treatment.

Effect of omeprazole on antiplatelet activities of W1 / 国际药学研究杂志

Objective To investigate the antiplatelet effects of candidate drug W1 when combined with omeprazole,respec?tively.Methods The experimental rats were randomly divided into 5 groups:control group,clopidogrel(10 mg/kg)group,clopido?grel(10 mg/kg)+omeprazole(80 mg/kg)group,W1(3 mg/kg)group,and W1(3 mg/kg)+omeprazole(80 mg/kg)group.Four hours after oral administration of the drugs,the rats were measured for their platelet aggregation rate;Western blot was used to deter?mine the protein expressions of P2Y12 receptor,P-Akt and P-Erk.Results For the platelet aggregation rate,compared with the con?trol group,the 4 groups decreased significantly(P<0.01);the platelet aggregation rate in the clopidogrel + omeprazole group in?creased significantly than that in the clopidogrel group(42% and 20.4%,respectively,P<0.01);the platelet aggregoction rate (30.9%)in W1+omeprazole group was significantly higher(P<0.01)than that in the W1 group(20.5%),which was lower than that in the clopidogrel+omeprazole group(P<0.01).For the protein expression detected by the western blotting,there were no signif?icant changes in the expression of P2Y12 receptor on the platelet surface,in the clopidogrel or W1 group in comparison with the clopi?dogrel+omeprazole or W1+omeprazole group,respectively,while the phosphorylation level of Akt and Erk was up-regulated in the clopidogrel+omeprazole or W1+omeprazole group compared with the clopidogrel or W1 group,and the up-ragulatory effect of omepra?zole was weaker in the W1+omeprazole group than that in the clopidogrel+omeprazole group. Conclusion Combined use of omepra?zole could inhibit the antiplatelet activities of clopidogrel or W1,with the inhibitory effect weaker in W1 group than in clopidogrel group,suggesting that the risk for the combination of omeprazole with W1 is likely less than that for the combination with clopidogrel.

Research progress of platelet function tests in antiplatelet effect on monitoring P2Y12 receptor antagonist / 天津医药

The P2Y12 receptor antagonist is used widely in prevention and treatment of cardiovascular and cerebrovascular disease. Monitoring changes of platelet function after treatment can improve the prognosis of patients. The platelet function test is the important way to evaluate high residual platelet reactivity after antiplatelet treatment, including light transmission aggregometry (LTA), whole blood impedance aggregometry assay (WBIA), vasodilator- stimulated phosphoprotein (VASP), thrombelastogram (TEG), platelet function analyzer- 100 (PFA-100) and VerifyNow system (VerifyNow). It is very different for the reflecting ability with residual reactivity of platelets among these tests after anti-platelet therapy, and also significant difference for assessment effect. Among them, LTA is a classic method for the curative effect evaluation of anti-platelet agents, which is convenient and cheap, but it is susceptible to the operating and environment interference. The clinical application of WBIA is less, and which lacks threshold value for assessment. VASP is sensitive for the changes of platelet function, but the test is complex and expensive. TEG can monitor the inhibition ratio of drugs on anti-platelets, but it needs to verify the safety of treatment. It is not clear for sensitivity and specificity with monitoring anti-platelet agent by PFA-100. VerifyNow is effective and reliable, but the cost is high. The evidence of clinical study shows that LTA, VASP and VerifyNow can reflect the effect of platelet inhibition of P2Y12 receptor antagonists sensitively, and is associated with the risk of major adverse cardiac events (MACE) in patients with cadiovascular diseases.

Effect of CYP2C19 polymorphism on platelet P2Y12 receptor signaling pathway in Chinese patients with stable coronary artery disease after the treatment of clopidogrel / 复旦学报（医学版）

Objective To investigate the molecular mechanism of the effect of CYP2C19 polymorphism on the efficacy of clopidogrel in patients with stable coronary artery disease (SCAD).Methods A total of 208 patients with coronary artery disease undergoing percutaneous coronary intervention (PCI) were included.The CYP2C19 variant alleles were detected by gene sequencing.Platelet reactivity was assessed by thrombelastograph at 24 h after 300 mg clopidogrel loading.P2Y12-Gi signaling was measured by flow cytometric analysis of vasodilator-stimulated phosphorylation-platelet reactivity index (VASP-PRI) and Akt phosphorylation (P-Akt) index.Results Among 208 patients,40.9％ were classified as CYP2C19 * 1/* 1 (non-carriers) with no loss-of-function (LOF),44.7％ as CYP2C19 * 1/* 2 or CYP2C19 * 1/* 3 (one LOF carriers) and 14.4％ as CYP2C19 * 2/*2 or CYP2C19 * 2/* 3 (two LOF carriers).Both postclopidogrel platelet aggregation and VASP-PRI increased by the presence of one LOF allele,and were even more pronounced with the presence of two LOF alleles.In contrast,P-Akt index only increased in two LOF carriers.VASP-PRI was positively associated with postclopidogrel platelet aggregation (r =0.661,P＜0.001),but not with P-Akt index.Conclusions The two CYP2C19 LOF carriage was associated with more active state of P2Y12-Gi signaling in postclopidogrel platelet in Chinese patients with SCAD.

Association between P2Y12 Genetic Polymorphisms and Clinical Efficacy of Clopidogrel in the Patients with Cardiovascular and Cerebrovascular Diseases:a Meta-analysis / 中国药师

Objective:To systematically review the association between P2Y12 genetic polymorphisms and the clinical safety of clopidogrel in the patients with cardiovascular and cerebrovascular diseases. Methods:Retrieved from MEDLINE,Embase,CNKI,Si-noMed and Wanfang Database (from January 1995 to December 2016),array researches about the association between P2Y12 genetic polymorphisms and the clinical safety of clopidogrel were collected including the studies of patients taking clopidogrel with cardiovascu-lar and cerebrovascular diseases and excluding animal experimental studies. The bias of recruited studies was assessed and meta-analy-sis was performed by RevMan 5.1 software. Results:Totally 10 array researches(3 in English and 7 in Chinese) were enrolled invol-ving 5 223 patients. There were no statistical differences between T allele gene carriers and CC genetype patients of C34T in the inci-dence of adverse cardiovascular events (RR=0.95,95% CI:0.82-1.09,P=0.46). The incidence of adverse cardiovascular events in T allele gene carriers of G52T was higher than that in GG genetype patients(RR=1.99,95% CI:1.63-2.44,P<0.000 01). The incidence of clopidogrel resistance in T allele gene carriers of C34T was higher than that in CC genetype patients(RR=2.02,95% CI:1.37-2.96,P=0.000 4). The incidence of clopidogrel resistance in T allele gene carriers of G52T was higher than that in GG gene-type patients (RR=1.56,95% CI:1.04-2.34,P=0.03). There was no statistical difference in the risk of clopidogrel resistance be-tween C allele gene carriers of i-T744c and T allele gene no-carriers(RR=0.99,95% CI:0.78-1.25,P=0.92). Conclusion:T al-lele gene carriers of C34T might be a risk factor of the occurrence of clopidogrel resistance,T allele gene carriers of G52T might be a risk factor of the occurrence of cardiovascular events and clopidogrel resistance,and C allele gene carriers of i-T744c might not increase the danger of the occurrence of clopidogrel resistance.

Inhibidores del receptor plaquetario P2Y12. Parte 1 de 2: escenario de acción, farmacología, aplicación clínica y limitaciones de su uso / Platelet P2Y12 receptor inhibitors. Part 1 of 2: Scenario of action, pharmacology, clinical application, and limitations of its use

Resumen: las enfermedades cardiovasculares, incluidas las afecciones del corazón, del cerebro y de los vasos sanguíneos en general, representan la primera causa de muerte a nivel mundial, con diecisiete millones y medio de muertes cada año. La prevención primaria y secundaria de las enfermedades aterotrombóticas, como el infarto agudo de miocardio, el accidente cerebrovascular y las enfermedades trombóticas, además de las medidas generales para el control de los factores de riesgo tales como la obesidad, el sedentarismo, el tabaquismo, la hipertensión arterial y la diabetes, se han centrado en el control de la agregación plaquetaria. El antiagregante plaquetario por excelencia o universal, sobre todo en la prevención primaria, es la aspirina y la terapia dual con la combinación de aspirina y un inhibidor del receptor plaquetario P2Y12, principalmente el clopidogrel, es usada en la prevención secundaria y en los casos de resistencia a la aspirina. En el momento, se dispone para uso clínico de seis inhibidores del receptor plaquetario P2Y12: la ticlopidina, el clopidogrel, el prasugrel, el ticagrelor, el cangrelor y el elinogrel. En este primer módulo, de dos que serán presentados, se abordará el uso de los inhibidores del receptor plaquetario P2Y12 en la práctica del día a día en la prevención primaria y secundaria de las enfermedades aterotrombóticas, enfocado en el análisis del papel de las plaquetas en la fisiopatología de la enfermedad aterotrombótica y la descripción de los seis inhibidores del receptor plaquetario P2Y12 disponibles ahora y en el futuro. En un segundo módulo se hará una aproximación al concepto de la resistencia a los inhibidores del receptor plaquetario P2Y12, su diagnóstico desde el punto de vista del laboratorio y las diferentes alternativas de manejo cuando se presenta resistencia a uno de estos medicamentos. (AU)

Abstract: Cardiovascular diseases, including in general heart diseases, brain, and blood vessels are the leading cause of death worldwide with 17.000.000 of deaths each year. Primary and secondary prevention of atherothrombotic diseases, as acute myocardial infarction, stroke, and thrombotic disorders, besides to the general measures for risk factors control such as obesity, sedentary lifestyle, smoke, high blood pressure, and diabetes, have focused on platelet aggregation control. The antiplatelet agent par excellence or universal, especially in primary prevention, is aspirin, and dual therapy with the combination of aspirin and a platelet receptor inhibitor P2Y12, with clopidogrel as the most used, for secondary prevention and in cases of aspirin resistance. Currently, six P2Y12 platelet receptor inhibitors are available for clinical use: ticlopidine, clopidogrel, prasugrel, ticagrelor, cangrelor, and elinogrel. In this first of two modules, the use of P2Y12 receptor inhibitors in daily practice in the primary and secondary prevention of atherothrombotic diseases will be addressed focused on the analysis of the platelets role in atherothrombotic disease pathophysiology and description of the six P2Y12 platelet receptor inhibitors available now and in the future. In a second module, we will approach the concept of resistance to platelet P2Y12 receptor inhibitors, its diagnosis from the laboratory point of view and the different management alternatives when resistance to one of these drugs is present. (AU)

Importancia de las plaquetas en las enfermedades cardiovasculares / Importance of platelets in cardiovascular diseases

La fascinante historia de las plaquetas, aquellos pequeños fragmentos celulares que se desprenden del citoplasma de los megacariocitos, se remonta a los siglos XVII y XVIII [1]; no obstante, lo que hoy representan en el contexto de la salud y la enfermedad se inicia cuando sir William Osler (1849-1919), el padre de la medicina interna, las describe por primera vez en el año 1874 [2] y cuando Giulio Bizzozero (1846-1901) las caracteriza, en 1881, como un nuevo elemento forme de la sangre [3]. Con el correr del tiempo, y a partir de los primeros años del siglo xx, las plaquetas se fueron posicionando como un parámetro más para incluir en el hemograma y, desde el punto de vista clínico, para definir y caracterizar algunas entidades hematológicas relacionadas con su recuento, como la púrpura trombocitopénica idiopática, hoy conocida como trombocitopenia autoinmune [4] y llamada, originalmente, enfermedad de Werlhof, que fue descrita en 1735 [5], muchísimos años antes de que se descubriesen las plaquetas y su papel en la hemostasia; al igual que aquellas asociadas a su morfología y funcionamiento, como el síndrome de Bernard-Soulier [6] y la trombastenia de Glanzmann [7], entre otras. El desarrollo tecnológico relacionado con las plaquetas en la primera mitad del siglo XX se limitó a su recuento manual con cámaras desarrolladas para ese fin [8], y al tiempo de sangría [9] como única prueba de la función plaquetaria por muchos años; esta última aún ofertada en algunos laboratorios clínicos a pesar de ser una prueba obsoleta de acuerdo a lo definido claramente por el CAP (del inglés, College of American Pathology) y la ASCP (del inglés, American Society for Clinical Pathology) [10]. Todo lo anterior es suficiente para entender por qué el papel de las plaquetas fue considerado, por muchos años, como secundario. Dos inventos revolucionaron la hematología, en general, y en el hemogramalos parámetros plaquetarios, en particular: • El primero se desarrolló en 1953 y es conocido como principio de Coulter, el cual se define como un método que utiliza un campo eléctrico para contar y dimensionar partículas que se encuentran en suspensión en el líquido conductor, como reza en su patente [11], y que hoy se aplica en todos los contadores electrónicos de hematología y en las citometrías de flujo. Este principio revolucionó la hematología en general y, en el caso particular de las plaquetas, no solo mejoró su recuento, que antes se hacía por métodos manuales, sino que introdujo nuevos parámetros plaquetarios de utilidad clínica en el hemograma de rutina, como el volumen medio plaquetario, el ancho de distribución de las plaquetas, el plaquetocrito y el índice de plaquetas inmaduras o plaquetas reticuladas [12]. (AU)

tromAgregación plaquetaria, ADP (inhibidores del receptor P2Y12) / Platelet aggregation, ADP (P2Y12 receptor inhibitors)

Código SCPC (Sociedad Colombiana de Patología Clínica): 10240. Código CUPS (Codificación Única de Procedimientos en Salud): no aplica. Sección: Hematología. Nivel de complejidad: alto. Metodología: agregación plaquetaria por transmisión de luz. Sinónimos: prueba de inhibidores P2Y12 Definición La agregación plaquetaria con ADP es una prueba que mide el porcentaje de agregación inducida por el adenosín difosfato (ADP) a una concentración de 20 µM mediante una prueba de agregometría por transmisión de luz para medir la actividad como antiagregantes plaquetarios de los inhibidores del receptor P2Y12 y, a su vez, la posible resistencia a estos. Espectro clínico de aplicación Las pruebas de función plaquetaria simulan el proceso fisiológico de activación y agregación plaquetaria, de forma que permiten la cuantificación de la respuesta plaquetaria y la identificación de una función anormal posterior a la estimulación con agentes específicos. La agregación plaquetaria con ADP es una prueba empleada para el diagnóstico de la no respuesta (resistencia) al tratamiento con los inhibidores del receptor P2Y12 in vitro, entendida como la incapacidad del medicamento para bloquear apropiadamente la reactividad plaquetaria en un individuo que lo está tomado regularmente y a la dosis indicada, que se observa como un aumento in vitro de la agregación plaquetaria a dosis de 20 µM de ADP. La resistencia a los inhibidores del receptor P2Y12 puede ser debida a múltiples factores, entre los que se incluyen los demográficos (edad avanzada), los genéticos (polimorfismos de proteínas y enzimas para la absorción y el metabolismo hepático de estos medicamentos), celulares (estados de hiperactividad plaquetaria), interferencias medicamentosas, como las presentadas con los inhibidores de la bomba de protones, las estatinas lipófilas y los bloqueadores de canales de calcio, y comorbilidades del paciente (insuficiencia renal, diabetes mellitus, obesidad y enfermedad coronaria). (AU)

Resistencia a los inhibidores del receptor plaquetario P2Y12: después de la aspirina, llegó el momento de detectarla y de optar por un manejo personalizado / Resistance to inhibitors of the platelet receptor P2Y12: after aspirin, it was time to detect it and opt for a personalized management

Los enfoques para la reducción del riesgo cardiovascular, tanto en la prevención primaria como en la secundaria, han incluido, tradicionalmente, cambios del comportamiento, por ejemplo, en la dieta [1], la actividad física [2] y dejar de fumar [3], al igual que mejoras en la gestión de los factores de riesgo, por ejemplo, mediante el control de la diabetes [4], de la hipertensión arterial [5] y de los lípidos [6]. No obstante lo anterior, las enfermedades cardiovasculares en general, incluidas las afecciones del corazón, del cerebro y de los vasos sanguíneos, representan la principal causa de muerte a nivel mundial que, de acuerdo con la Organización Mundial de la Salud (OMS), corresponden a más de 17.500.000 de muertes cada año, entre ellas, 7.400.000 por ataques cardíacos y 6.700.000 por ictus isquémico [7]. Además de estas medidas convencionales para la prevención primaria y secundaria de las enfermedades cardiovasculares, se ha utilizado la antiagregación plaquetaria con aspirina, en el primer caso [8], y con terapia dual, compuesta por aspirina combinada con un inhibidor del receptor plaquetario P2Y12, en el segundo [9-14]. Cómo sucede con frecuencia, cuando se encuentra una solución que funciona frente a un problema, como lo son las enfermedades cardiovasculares y sus desenlaces tromboembólicos, aparece un nuevo inconveniente que, en el caso de los antiagregantes plaquetarios, se expresa como resistencia a los medicamentos utilizados y lleva al paciente a quedar expuesto a desenlaces aterotrombóticos, en muchos casos fatales. Es así como la resistencia a la aspirina, descrita en 1990 [15], presenta una prevalencia que oscila entre el 0,4% [16] y el 56,8% [17], la cual es explicable, en gran parte, en función de los criterios que la definen, los métodos utilizados, la población estudiada y las comorbilidades de los pacientes analizados, entre otras circunstancias. Del otro lado, la resistencia a los inhibidores del receptor plaquetario P2Y12, en particular al clopidogrel, el medicamento más utilizado de este grupo, fue descrita en 2002 [18] y presenta una prevalencia que oscila entre el 6% [19] y el 44% [20], que es explicable, en gran parte, por las mismas circunstancias antes citadas para la aspirina. Con el desarrollo tecnológico en las dos últimas décadas, relacionado con la actividad plaquetaria, en particular la agregación plaquetaria [21], y las pruebas sucedáneas como la agregagometría de impedancia, el PFA-100 (del inglés, Platelet Funtion Analizer-100; Siemens Healthcare Diagnostics, Inc., Deerfield, Illinois, Estados Unidos) y el VerifyNow®, además de otras como la citometría de flujo y la tromboelastografía, hoy es posible seguir mediante pruebas de laboratorio la antiagregación plaquetaria tanto con aspirina como con los inhibidores del receptor plaquetario P2Y12. (AU)

Effects of Platelet Number and Platelet Indices on Platelet Reactivity in Patients Treated with Clopidogrel or Ticagrelor / 대한내과학회지

BACKGROUND/AIMS: Platelet counts and characteristics can influence platelet reactivity during antiplatelet therapy. We compared the effects of both platelet count and indices on platelet reactivity between patients who were treated with either clopodogrel or ticagrelor. METHODS: Patients with coronary artery disease who underwent percutaneous coronary intervention were randomly assigned to either the clopidogrel (n = 63) or ticagrelor (n = 65) groups. Platelet count, platelet indices (including mean platelet volume, platelet distribution width, platelet large cell ratio, and immature platelet fraction), and platelet reactivity were measured before intervention, and 48 hours and 30 days post-intervention. High on-treatment platelet reactivity (HPR) was defined as ≥ 47 unit as assessed by multiple electrode platelet aggregometry. RESULTS: Baseline platelet reactivity was similar between the two groups; however, at 48 hours and 30 days, platelet reactivity was significantly lower in the ticagrelor group than in the clopidogrel group. Platelet count, mean platelet volume, platelet distribution width, platelet large cell ratio, and immature platelet fraction were significantly correlated with platelet reactivity in the clopidogrel group; however, these correlations were attenuated in the ticagrelor group. The use of clopodogrel (hazard ratio [HR] 4.1, 95% confidence interval [CI] 1.4–11.9; p = 0.010) and platelet count (HR 9.7, 95% CI 2.9–32.7; p = 0.001) were independent predictors for 30 day HPR. Platelet count was an independent predictor of HPR in the clopidogrel group but not in the ticagrelor group. CONCLUSIONS: Platelet count and indices are significantly correlated with platelet reactivity. However, antiplatelet treatment with ticagrelor could overcome these associations.

Perioperative management and monitoring of antiplatelet agents: a focused review on aspirin and P2Y12 inhibitors / 대한마취과학회지

Platelets play pivotal roles in hemostasis as well as pathological arterial thrombosis. The combination of aspirin and a P2Y₁₂ inhibitor has become the mainstay therapy in the ageing population with cardiovascular conditions, particularly during and after percutaneous coronary intervention. A number of novel P2Y₁₂ inhibitors has become available in the recent years, and they markedly vary in pharmacokinetic and pharmacodynamic properties. Perioperative physicians today face a challenge of preventing hemorrhage due to platelet inhibitors, while minimizing thrombotic risks. There are several point-of-care platelet function tests available in the peri-procedural assessment of residual platelet aggregation. However, these platelet function tests are not standardized in terms of sample processing, agonist type and potency as well as methods of detecting platelet activity. Understanding the differences in pharmacological properties of antiplatelet agents, principles of platelet function tests, and pertinent hemostatic strategies may be useful to anesthesiologists and intensivists who manage perioperative issues associated with antiplatelet agents. The objectives of this review are: 1) to discuss clinical data on aspirin and P2Y12 inhibitors relating to perioperative bleeding, 2) to outline different features of point-of-care platelet function tests, and 3) to discuss therapeutic options for the prevention and treatment of bleeding associated with antiplatelet agents.

Comparison of the Infarct Size between the Loading of Ticagrelor and Clopidogrel in Patients with Acute Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND AND OBJECTIVES: Ticagrelor is considered a potent antiplatelet agent compared to clopidogrel. However, there are no studies regarding the effect of ticagrelor loading on infarct size in patients with ST-segment elevation myocardial infarction (STEMI) in a primary percutaneous coronary intervention (PCI) setting. SUBJECTS AND METHODS: In this single-center, randomized, open-label study, 188 patients who underwent primary PCI for STEMI were enrolled (92 patients in the clopidogrel group and 96 in the ticagrelor group) and compared the infarct size by technetium-99m (Tc-99m) tetrofosmin single-photon emission computed tomography (SPECT) and serial cardiac biomarker levels between the groups. SPECT was performed at a median of 2 days after PCI. RESULTS: Baseline clinical and procedural characteristics were similar between the groups. Infarct size on SPECT, was similar between the 2 groups (28.1%±34.5% vs. 32.8%±29.2%; p=0.169). At all time-points after PCI (8, 24, and 48 hours), the peak levels of creatine kinase-myocardial band (CK-MB) and troponin T were lower in the clopidogrel group. The clopidogrel group showed lower cumulative troponin T levels than the ticagrelor group (12.59±10.66 vs. 17.67±19.51 ng/mL; p=0.029). CONCLUSION: Ticagrelor loading before primary PCI was not associated with reduced myocardial infarct size during the first 48 hours, compared to clopidogrel loading.

Effect of morphine on pharmacokinetics and pharmacodynamics of P2Y12 receptor antagonists / 中国药理学通报

P2Y12 receptor antagonists and morphine are often recommended in patients with acute myocardial infarction.P2Y12 receptor antagonists can rapidly and potently reduce the platelet activity and prevent future thrombotic events.Meanwhile,combined morphine is used to relieve symptoms of angina.A number of studies have confirmed that morphine can decrease plasma concentrations of clopidogrel and impair its anti-platelet activity,which may lead to poor response in clopidogrel-treated patients with acute coronary syndrome.The randomized trials in healthy volunteers and patients with acute myocardial infarction also confirmed the similar drug-drug interaction between morphine and ticagrelor or prasugrel.Although the P2Y12 receptor antagonists combined with morphine are still used for myocardial infarction patients,there are few report on the objective evaluation of this drug interaction.This review,based on the findings of experimental as well as observational and randomized clinical studies,summarizes completely the drug interactions between oral P2Y12 receptor antagonists and morphine.

Study on the Correlation of Gene Polymorphism with Antiplatelet Efficacy of Clopidogrel in PAD Patients / 中国药房

OBJECTIVE:To investigate the correlation of gene polymorphism in peripheral artery disease(PAD)patients with antiplatelet efficacy of clopidogrel. METHODS:Reviewing related domestic and foreign literatures in recent years,the correlation of gene polymorphism in PAD patients with antiplatelet efficacy of clopidogrel was summarized and analyzed. RESULTS&CON-CLUSIONS:At present,a variety of genes associated with clopidogrel antiplatelet efficacy and major adverse cardiovascular events (MACE)have been identified,including cytochrome P450(CYP)2C19,adenosine three phosphate binding cassette B subfamily 1 (ABCB1),paraoxonase 1 (PON1) and adenosine diphosphate P2Y12 receptor (P2Y12),etc. CYP2C19*2,*3 allele may reduce the antiplatelet effect of clopidogrel. Their correlation has been confirmed by a number of studies,and study results are broadly con-sistent. Mutations in the ABCB1 C3435T and PON1 Q192R sites may lead to a lower response to clopidogrel and increase the risk of MACE;but there is a lack of large-scale prospective clinical studies,and the present results are inconsistent. P2Y12 gene poly-morphism in PAD patients has not been found to be significantly associated with clopidogrel efficacy.

Evaluation of clopidogrel response variability and identification of the CYP2C19 polymorphism in Mexican patients / Evaluación de la variabilidad en la respuesta a clopidogrel e identificación del polimorfismo CYP2C19 en pacientes mexicanos

Abstract Objective Drug inhibition of platelet P2Y12 adenosine diphosphate receptor has reduced the incidence of adverse cardiovascular events after percutaneous coronary interventions. The analysis of the phosphorylation status of vasodilator-stimulated phosphoprotein by flow cytometry has shown a predictive value for adverse events and stent thrombosis. Polymorphisms of CYP2C19 in high risk patients may also relate to adverse cardiovascular events. Methods Ninety patients were enrolled. Patients received a 600 mg clopidogrel loading dose. Blood samples were obtained at the time of the procedure and 24 h later, platelet reactivity was assessed by vasodilator-stimulated phosphoprotein phosphorylation measurement using flow cytometry. Low response to clopidogrel was defined as a platelet reactivity index ≥ 50%. The presence of CYP2C19*2 was identified with the restriction enzyme Smal. Results Mean platelet reactivity index: 53.45 ± 22.48% in the baseline sample and 57.14 ± 23.08% at 24 h (p = 0.183); 40% of patients behaved as good responders, the rest behaved as non-responders with 38% of patients showing platelet reactivity indexes between 50-70% and 22% showing indexes above 70%. The CYP2C19*2 polymorphism was found in 17% of patients, with a 3.9% AA homozygous genotype carriers. Conclusion Response to the clopidogrel loading dose showed a wide variability among patients with 40% responding to the drug according to previously established cut-off values. Our results showed that 3.9% of patients show the AA genotype. To our knowledge, this is the first study involving clopidogrel response by flow citometry and genotype typification in Mexican Mestizo population.

Resumen Objetivo La inhibición del receptor plaquetario P2Y12 se ha asociado con reducción en incidencia de eventos cardiovasculares mayores en pacientes sometidos a intervenciones coronarias percutáneas. El estudio de la fosfoproteína estimulada por vasodilatadores mediante citometría de flujo tiene valor predictivo para desarrollo de eventos adversos y trombosis del stent. Los polimorfismos del CYP2C19 en pacientes de alto riesgo pueden también asociarse con eventos adversos. Método 90 pacientes, dosis de carga de clopidogrel: 600 mg. Se obtuvieron muestras de sangre basales y post-24 horas. La reactividad plaquetaria se estudió mediante medición de fosfoproteína estimulada por vasodiatadores por citometría de flujo. Se consideró baja respuesta al clopidogrel un índice de reactividad plaquetaria ≥50%. La presencia del CYP2C19*2 se identificó con enzima de restricción Smal. Resultados La media del índice de reactividad plaquetaria fue: 53.45 ± 22.48% en muestras basales y 57.14 ± 23.08% a 24 h (p = 0.183); 40% de los pacientes repondieron a clopidogrel, el resto de comportó como no-respondedores, un 38%, mostró índices de reactividad plaquetaria entre 50 -70% y 22%, índices > 70%. El polimorfismo CYP2C19*2 se encontró en 17% pacientes, con un 3.9% portadores de genotipo homozigótico AA. Conclusiones La respuesta a clopidogrel mostró amplia variabilidad entre pacientes, el 40% presentó respuesta de acuerdo con puntos de corte pre establecidos. Un 3.9% de los pacientes presentó genotipo AA. Consideramos que este es el primer estudio realizado en población mestizo-mexicana utilizado citometría de flujo para evaluar la respuesta a clopidogrel así como la tipificación genética de los pacientes.