Microfluidic Chip and Flow Cytometry for Examination of the Antiplatelet Effect of Ticagrelor / 中国医学科学院学报

Objective To examine the antiplatelet effect of ticagrelor by microfluidic chip and flow cytometry under shear stress in vitro. Methods Microfluidic chip was used to examine the effect of ticagrelor on platelet aggregation at the shear rates of 300/s and 1500/s.We adopted the surface coverage of platelet aggregation to calculate the half inhibition rate of ticagrelor.The inhibitory effect of ticagrelor on ADP-induced platelet aggregation was verified by optical turbidimetry.Microfluidic chip was used to construct an in vitro vascular stenosis model,with which the platelet reactivity under high shear rate was determined.Furthermore,the effect of ticagrelor on the expression of fibrinogen receptor (PAC-1) and P-selectin (CD62P) on platelet membrane activated by high shear rate was analyzed by flow cytometry. Results At the shear rates of 300/s and 1500/s,ticagrelor inhibited platelet aggregation in a concentration-dependent manner,and the inhibition at 300/s was stronger than that at 1500/s (both P<0.001).Ticagrelor at a concentration ≥4 μmol/L almost completely inhibited platelet aggregation.The inhibition of ADP-induced platelet aggregation by ticagrelor was similar to the results under flow conditions and also in a concentration-dependent manner.Ticagrelor inhibited the expression of PAC-1 and CD62P. Conclusion We employed microfluidic chip to analyze platelet aggregation and flow cytometry to detect platelet activation,which can reveal the responses of different patients to ticagrelor.

Disnea secundaria a ticagrelor posterior a arteriografía coronaria. Reporte de caso / Dyspnea secondary to ticagrelor posterior to coronary arteriography. Case report

Resumen Los antiagregantes plaquetarios son medicamentos ampliamente utilizados para la prevención y tratamiento de patologías aterotrombóticas, como lo es el síndrome coronario agudo. A pesar de tener un efecto benéfico, no están exentos de ocasionar múltiples alteraciones a nivel sistémico, como lo es la disnea en pacientes sometidos a manejo con ticagrelor. Se expone el caso de un paciente de 66 años con antecedente de cardiopatía isquémico-hipertensiva, tabaquismo pesado y alergia al ácido acetilsalicílico (ASA), con requerimiento de 2 arteriografías coronarias, quien presenta disnea en reposo en menos de 24 horas posterior al inicio de manejo antiagregante tromboprofiláctico con ticagrelor, que resuelve de forma satisfactoria tras la suspensión del medicamento. Al ser un efecto secundario relativamente frecuente en el marco del uso del ticagrelor, se hace relevante revisar los hallazgos en la literatura actual sobre la aparición de disnea en pacientes tratados con dicho fármaco, para así tener en cuenta posibles recomendaciones acerca del manejo de la disnea asociada a ticagrelor, basadas en el conocimiento actual. MÉD.UIS.2022;35(1): 9-15.

Abstract Antiplatelet agents are widely used drugs for the prevention and treatment of atherothrombotic pathologies such as acute coronary syndrome, however, despite having a beneficial effect, they're not exempt from causing multiple systemic alterations, such as dyspnea in patients undergoing management with ticagrelor. We will now present the case of a 66-year-old patient with a history of hypertensive ischemic heart disease requiring 2 cardiac catheterizations, heavy smoking and allergic to Acetyl Salicylic Acid (ASA) who presented dyspnea at rest in less than 24 hours after the start of thromboprophylaxis management with ticagrelor, that resolves satisfactorily after discontinuation of the drug. Because it is a frequent side effect in the framework of the use of ticagrelor, it's relevant to review the current literature on the appearance of dyspnea in patients treated with ticagrelor, to highlight recommendations for the management of dyspnea associated with ticagrelor based on current knowledge. MÉD.UIS.2022;35(1): 9-15.

Reacción de hipersensibilidad a ticagrelor / Ticagrelor-induced hypersensitivity reaction

Introducción: el ticagrelor es un medicamento antiagregante plaquetario utilizado como prevención secundaria en pacientes con síndrome coronario agudo. Dentro de las reacciones adversas reportadas secundarias a su administración se encuentran hemorragias, cefalea, disnea, epistaxis, pausas ventriculares o bradicardia, hiperuricemia y elevación de la creatinina. No obstante, las reacciones de hipersensibilidad han sido raras. Presentación del caso: paciente masculino de 63 años con infarto agudo del miocardio, elevación de ST y documentándose en cateterismo cardíaco ectasia y enfermedad de flujos lentos. Requirió terapia de antiagregación dual con ácido acetilsalicílico (ASA) y ticagrelor, con posterior urticaria de origen medicamentoso según concepto de dermatología. Se manejó con esteroide tópico, antihistamínico oral y retiro de ticagrelor. Se considera un caso raro de reacción al antiagregante plaquetario descrito.

Introduction: ticagrelor is an antiplatelet therapy used for secondary prevention in patients with acute coronary syndrome. Adverse effects of ticagrelor are hemorrhage, headache, dyspnea, epistaxis, ventricular pauses or bradycardia, hyperuricemia and elevation of creatinine level. However, hypersensitivity reaction of ticagrelor is rarely recognized. Case report: we present a 63-year-old male patient diagnosed with acute myocardial infarction, ST-segment elevation and ectasia and low blood flow disease documented by coronary angiogram. He required dual antiplatelet therapy with acetylsalicylic acid (ASA) and ticagrelor, developing drug-induced urticaria according to dermatology consultation. He was treated with topical steroids, oral antihistamines and ticagrelor discontinuation. This case is considered a rare case of reaction to the antiplatelet agent described herein.

Síndrome de respuesta inflamatoria sistémica por ticagrelor / Systemic inflammatory response syndrome associated with use of ticagrelor

Resumen El ticagrelor es un antiagregante plaquetario que actúa a través de la unión reversible a los receptores P2Y12 de la adenosina-difosfato. En el síndrome coronario agudo, ha demostrado reducir el riesgo de eventos cardiovasculares mayores como infarto de miocardio, accidente cerebrovascular y muerte. Si bien se han descripto en detalle ciertas complicaciones hemorrágicas, renales, hepáticas y respiratorias por el uso del ticagrelor, otros efectos adversos menos frecuentes de la droga no han sido adecuadamente escla recidos. Presentamos el caso de un paciente con un síndrome de respuesta inflamatoria sistémica secundario al uso de ticagrelor.

Abstract Ticagrelor is anantiplatelet agent which acts through reversible binding to the P2Y12 adenosine-diphosphate recep tors. In acute coronary syndromes it has been shown to reduce the risk of major cardiovascular events such as myocardial infarction, stroke and death. Although some hemorrhagic, kidney, liver and respiratory complications have been described in detail with the use of ticagrelor, other less frequent adverse effects are not so well clari fied. We report the case of a patient with a systemic inflammatory response syndrome secondary to the use of ticagrelor.

The efficacy and safety of ticagrelor versus clopidogrel in elderly patients with acute coronary syndrome undergoing percutaneous coronary intervention / 中华心血管病杂志

Objective: To compare the efficacy and safety of ticagrelor and clopidogrel in elderly Chinese patients with acute coronary syndrome (ACS) underwent percutaneous coronary intervention (PCI) in the real world. Methods: This study is a post-hoc analysis of a single center, retrospective cohort study. Between March 2016 and March 2018, elderly (age≥65) ACS patients who underwent PCI in the General Hospital of Northern Theater Command were included in the study. The patients were grouped according to P2Y12 receptor inhibitor. The primary endpoints of this study were ischemic events during the 2-year follow-up, which were defined as the composite of cardiac death, myocardial or stroke. The secondary efficiency endpoints included all-cause death and BARC 2, 3, 5 bleeding events. Results: A total of 4 022 elderly (mean age: (71.5±5.3) years) ACS patients were included in this study. Based on the choice of P2Y12 receptor inhibitor, patients were divided into clopidogrel (n=3 201) and ticagrelor (n=821) groups. Incidences of ischemic events (3.2% (26/821) vs. 5.6% (179/3 201), P=0.005) at 2 years were significantly lower in ticagrelor group compared to clopidogrel group. BARC 2, 3, 5 bleeding events (1.7% (14/821) vs. 1.6% (52/3 201), P=0.818) were comparable between the two groups. The incidence of all-cause death (1.5% (12/821) vs. 4.1% (132/3 201), P=0.005) were also lower in the ticagrelor group compared to the clopidogrel group. Clinical outcomes were consistent after adjusting for confounding factors, the incidence of ischemic events (HR= 0.637, 95%CI 0.409-0.991, P=0.046) and all-cause mortality (HR=0.402, 95%CI 0.213-0.758, P=0.005) was significantly lower in the ticagrelor group compared with the clopidogrel group. Risk of BARC 2, 3, 5 bleeding events were similar between the two groups (HR=0.957, 95%CI 0.496-1.848, P=0.897). Conclusion: In real-world clinical practice, for elderly patients with ACS undergoing PCI, ticagrelor use might reduce the incidence of long-term ischemic events and all-cause death without increasing the risk of bleeding.

The variation of serum uric acid levels among patients with myocardial infarction treated with ticagrelor and the association between serum uric acid and platelet reactivity / 中华心血管病杂志

Objectives: To compare the impact of ticagrelor or clopidogrel on serum uric acid levels among patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) and further evaluate the effects of variation of serum uric acid levels on platelet reactivity. Methods: STEMI patients who admitted to Fuwai Hospital from April 2017 to January 2020, and underwent primary PCI and discharged alive with aspirin and ticagrelor or clopidogrel were included in this study. Patients were divided into ticagrelor group and clopidogrel group. The baseline clinical data were collected. Serum uric acid and creatinine levels at baseline and 30 days post-PCI were measured. Light transmittance aggregometry was used to assess maximum aggregation rate induced by adenosine diphosphate and arachidonic acid. The changes of serum uric acid and creatinine were compared between the two groups. Multivariate logistic regression was performed to evaluate independent related factors for rise in the uric acid levels, and the effect of variation of serum uric acid level on platelet reactivity was analyzed. Results: A total of 967 patients were included, the age was (59.4±12.1) years, and 163 case were female. There were 550 cases in ticagrelor group (56.9%) and 417 cases in clopidogrel group (43.1%). Baseline serum uric acid and creatinine levels were similar between the 2 groups. At 30 days, the serum uric acid level [(347.2±96.5) mmol/L vs. (341.2±105.3) mmol/L, P=0.009] and absolute [46.4 (-2.4, 88.1) mmol/L vs. 25.0 (-21.9, 73.0) mmol/L, P=0.001] and percentage [13.2 (-0.01, 29.0) % vs. 7.9 (-5.7, 25.0) %, P=0.007] increase in the serum uric acid levels were significantly higher in ticagrelor group than in clopidogrel group. The level of serum creatinine at 30 days was significantly lower in ticagrelor group than in clopidogrel group [(89.7±21.3) μmol/L vs. (94.4±43.9) μmol/L, P<0.05], whereas there were no differences in absolute [8.0 (-1.4, 16.6) μmol/L vs. 7.8 (-2.0, 16.6) μmol/L] and percentage [10.5 (-1.7%, 22.6%) vs. 9.8 (-2.4%, 22.1%)] change in the serum creatinine between the 2 groups (all P>0.05). Logistic regression analysis showed that, after adjusting for confounding factors, ticagrelor therapy was an independent related factor of serum uric acid elevation (OR=1.582, 95% CI:1.023-2.447, P=0.039). The variation of the serum uric acid levels did not affect platelet aggregation and the percentage of high platelet reactivity in both groups. Conclusions: Ticagrelor use is related to a significant increase in the serum uric acid levels at 30 days post-PCI in this patient cohort. The variations in the uric acid levels do not increase the percentage of high platelet reactivity in STEMI patients treated with ticagrelor or clopidogrel.

Informe diário de evidências COVID-19: busca realizada em 24 de julho de 2020 / COVID-19 daily evidence report: search conducted on July 24, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referentes ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 21 artigos e 15 protocolos.

Effects of ticagrelor on cardiorespiratory fitness in patients after percutaneous coronary intervention / 中华心血管病杂志

Objective: To investigate the effects of ticagrelor on cardiorespiratory fitness in patients with coronary heart disease after percutaneous coronary intervention (PCI). Methods: A total of 1 073 patients, who were diagnosed as coronary heart disease and underwent cardiopulmonary exercise testing (CPET) within 1 year after PCI, were enrolled from September 2017 to September 2019 in Peking University Third Hospital, including 309 patients in ticagrelor group and 764 patients in clopidogrel group. Clinical information, blood test results, echocardiographic parameters, cardiorespiratory fitness related parameters (including peak oxygen uptake (VO(2)), anaerobic threshold VO(2), peak oxygen pulse (VO(2)/HR) and carbon dioxide ventilation equivalent (VE/VCO(2)) slope), coronary lesions and intervention information were obtained. Cardiopulmonary fitness related indexes were compared between the two groups, and the correlation between ticagrelor use and cardiopulmonary fitness related indexes was analyzed by multivariate logistic regression. Patients who underwent CPET within 1 month after PCI were included in the subgroup analysis. Results: In ticagrelor group, the age was (60.3±10.3) years, and 253(81.9%) cases were male. The age of clopidogrel group was (60.6±10.0) years, and there were 608(79.6%) males. No significant differences were observed in peak VO(2), anaerobic threshold VO(2), and peak VO(2)/HR between the two groups (all P>0.05), but the VE/VCO(2) slope was significantly higher in the ticagrelor group than in the clopidogrel group (30.075 (27.207, 33.603) vs. 28.853 (25.970, 32.336), P<0.001). Logistic regression analysis suggested that the peak VO(2), anaerobic threshold VO(2) and peak VO(2)/HR were not significantly correlated with the ticagrelor use (all P>0.05), while the VE/VCO(2) slope was independently correlated with ticagrelor use (OR=1.098, 95%CI 1.032-1.168, P=0.003). Subgroup analysis of patients who underwent CPET within 1 month after PCI also indicated that no significant difference were observed in peak VO(2), anaerobic threshold VO(2), peak VO(2)/HR and VE/VCO(2) slope between the two groups (all P>0.05). Logistic regression analysis suggested that the peak VO(2), anaerobic threshold VO(2) and peak VO(2)/HR were not significantly correlated with ticagrelor use (all P>0.05), while the VE/VCO(2) slope was significantly correlated with ticagrelor use (OR=1.132, 95%CI 1.030-1.244, P=0.010). Conclusion: Among coronary heart disease patients after PCI, treatment with clopidogrel does not result in significant decrease in exercise endurance as compared with patients treated with ticagrelor.

Diferencias en el tratamiento antitrombótico y pronóstico en función del sexo en pacientes con síndrome coronario agudo tratados con stent / Sex-specific differences in antithrombotic therapy and prognosis in patients with acute coronary syndrome treated with stent

Resumen Antecedentes y objetivo: El interés sobre la influencia del sexo en pacientes con síndrome coronario agudo (SCA) tratados con stent y nuevos antiagregantes inhibidores de P2Y12 en la práctica clínica es creciente. Se analizan las diferencias en función del sexo en el tratamiento con doble antiagregación plaquetaria (DAPT) y los eventos adversos isquémicos y hemorrágicos Materiales y métodos: Estudio prospectivo de pacientes consecutivos con diagnóstico de SCA tratados con stent coronario desde julio de 2015 hasta enero de 2016. Resultados: De un total de 283 pacientes incluidos, 75 (26.5%) correspondió a mujeres y 208 (73.5%) a hombres. La edad media fue de 71 ± 13 y 66.5 ± 13 años, respectivamente. Un 44% de mujeres se presentó como SCA con elevación del segmento ST contra un 52.4 de los hombres, p = 0.21. Las mujeres mostraron un mayor riesgo de sangrado (CRUSADE), sin diferencias en el riesgo isquémico (GRACE y TIMI). Se usaron stents farmacoactivos con más frecuencia en mujeres (88.9 vs. 75.5%, p = 0.04). Se observó una tendencia de menor prescripción del ticagrelor en mujeres (42.6 vs. 50.9%, p = 0.29) en favor de un mayor uso del clopidogrel. No se identificaron diferencias en cuanto a la prescripción del prasugrel. Las mujeres presentaron al año una menor mortalidad (1.4 vs. 6.7%, p = 0.19), aunque mayor sangrado (23.3 vs. 17.4%, p = 0.27). Conclusiones: En este estudio de pacientes consecutivos con SCA tratados con stent se registró una mayor prescripción de clopidogrel en las mujeres que en los hombres. Las mujeres presentaron una menor incidencia anual de mortalidad, pero mayor sangrado en comparación con los hombres, no significativo.

Abstract Aims and objective: Impact of sex-related differences in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention and treated with new P2Y12 inhibitors is not adequately characterised. We aimed to analyse gender-based differences in dual antiplatelet therapy, and adverse cardiovascular events and bleeding. Materials and methods: Prospective-observational study of the consecutive ACS patients treated with stent from July 2016 to January 2016, with a follow-up of 1 year. Results: We examined 283 patients, 75 (26.5%) women and 208 (73.5%) men. Women were older than men (71 ± 13 vs. 66,5 ± 13 years). There were 44% of women and 52% of men presenting with ST-elevation ACS (p = 0.21). Women had a higher bleeding risk (CRUSADE), without differences in the ischaemic risk (GRACE and TIMI). More women were treated with drug-eluting stent (88.9 vs. 75.5%, p = 0.04). There was a lower rate of ticagrelor prescription in women (42.6 vs. 50.9%, p = 0.29), in favour of clopidogrel. No differences were observed in prasugrel prescription. No significant differences were observed after a year of follow up, but women had a tendency towards lower mortality (1.4 vs. 6.7%, p = 0.19) and higher bleeding rates (23.3 vs. 17.4%, p = 0.27). Conclusions: In our study of patients presenting with ACS treated with stent, clopidogrel was preferred in women, whereas ticagrelor was the most frequent prescription in men. No significant differences were noted in clinical outcomes, but women experienced a tendency towards less mortality and more bleeding events.

Investigation of the protective effect of enoxaparin and ticagrelor pretreatment against ischemia-reperfusion injury in rat lung tissue

SUMMARY OBJECTIVES This study was conducted to reveal the possible protective effects of ticagrelor and enoxaparin pretreatment against ischemia-reperfusion (IR)-induced injury on the lung tissue of a rat model. METHODS Wistar albino rats were randomly divided into 4 groups as follows: group-1 (control-sham), group-2 (control-saline+IR), group-3 (ticagrelor+IR), group-4 (enoxaparin+IR). Before the ischemic period, saline, ticagrelor, and enoxaparin were administered to the 2nd-4th groups, respectively. In these groups, IR injury was induced by clamping the aorta infrarenally for 2 h, followed by 4 h of reperfusion except group-1. After the rats were euthanized, the lungs were processed for histological examinations. Paraffin sections were stained with Haematoxylin&Eosin (H&E) for light microscopic observation. Apoptosis was evaluated by caspase-3 immunoreactivity. Data were statistically analyzed using the SPSS software. RESULTS In the lung sections stained with H&E, a normal histological structure was observed in group-1, whereas disorganized epithelial cells, hemorrhage, and inflammatory cell infiltration were seen in the alveolar wall in group-2. The histologic structure of the treatment groups was better than that of group-2. Caspase-3(+) apoptotic cells were noticeable in sections of group-2 and were lower in the treatment groups. In group-4, caspase-3 immunostaining was lower than in group-3. In group-2, apoptotic cells were significantly higher than in the other groups (p<0.001). CONCLUSION Based on the histological results, we suggested that both therapies ameliorated the detrimental effects of IR. Caspase-3 immunohistochemistry results also revealed that pre-treatment with enoxaparin gave better results in an IR-induced rat injury model. In further studies, other parameters such as ROS and inflammatory gene expressions should be evaluated for accurate results.

RESUMO OBJETIVOS Este estudo foi realizado para revelar os possíveis efeitos protetores do ticagrelor e do pré-tratamento da enoxaparina no tecido pulmonar contra o modelo de lesão induzida por isquemia-reperfusão (IR). MÉTODOS Ratos albinos Wistar foram randomizados e divididos em quatro grupos: grupo 1 (controle-sham), grupo 2 (controle-salina + IR), grupo 3 (ticagrelor + IR), grupo 4 (enoxaparina + IR). Antes do período isquêmico, salina, ticagrelor e enoxaparina foram administrados nos grupos 2-4, respectivamente. Nesses grupos, a lesão de IR foi induzida pelo clampeamento da aorta na região da infrarrenal por duas horas, seguida por quatro horas de reperfusão, exceto no grupo 1. Após a sacrificação, os pulmões foram processados para exames histológicos. Secções de parafina foram coradas com hematoxilina e eosina (H&E) para observação microscópica de luz. A apoptose foi avaliada pela imunorreatividade da caspase-3. Os dados foram analisados estatisticamente pelo programa SPSS. RESULTADOS Nas secções pulmonares coradas com H&E, estrutura histológica normal foi observada no grupo 1, enquanto células epiteliais desorganizadas, hemorragia e infiltração de células inflamatórias foram observadas na parede alveolar no grupo 2. A estrutura histológica dos grupos de tratamento foi melhor que o grupo 2. Células apoptóticas caspase-3 (+) foram notadas em secções do grupo 2, e essas células foram mais baixas nos grupos de tratamento. No grupo 4, a imunocoloração com caspase-3 foi menor que no grupo 3. No grupo 2, as células apoptóticas foram significativamente maiores que nos outros grupos (p<0,001). CONCLUSÃO Com base nos resultados histológicos, sugerimos que ambas as terapias atenuaram os efeitos prejudiciais da RI. Resultados de imuno-histoquímica com caspase-3 também revelaram que o pré-tratamento com enoxaparina proporcionou melhores resultados no modelo de lesão induzida por IR. Em estudos posteriores, outros parâmetros, como ROS e expressões gênicas inflamatórias, devem ser avaliados quanto a resultados precisos.

Drogas antiplaquetarias de utilización en Síndrome Coronario Agudo / Antiplatelet drugs used in Acute Coronary Syndrome

Los medicamentos antiplaquetarios, representan el pilar del tratamiento farmacológico, en el síndrome coronario agudo. Su utilización pronta y precisa, permiten ganar minutos importantes en la toma de decisiones de estos pacientes, que permitan una resolución cabal y de optimo pronostico. Esta pequeña y práctica revisión pretende destacar las características más importantes de cada uno de ellos, que ofrezca al clínico optimizar la decisión del medicamento que representa la mejor estrategia terapéutica, en el contexto individual de cada paciente. Para esto se presentan de manera resumida los estudios más recientes que comparan los diferentes agentes, durante el síndrome coronario, que permitan un manejo más individualizado del paciente.

Antiplatelet drugs represent the main pharmacologic treatment on an acute coronary syndrome. Its fast, and precise utilization allow us gain important minutes on de decision making process of this patients, that allows a fast resolution with optimal prognosis. This practical small review pretends to pinpoint the most important characteristics of each one of this drugs that allows the clinician get the best decision on with drug offers the best therapeutic strategy on the individual context of the patient. So we present a summary of the latest trials that compare this agents on acute coronary syndrome that allows individualization o the patient management.

Dual platelet antiaggregation therapy after myocardial revascularization surgery

SUMMARY Coronary artery bypass graft (CABG) is a consolidated treatment in patients with coronary artery disease (CAD) for both symptom control and improvement of prognosis. The patency of venous grafts is still the most vulnerable point of the surgical treatment since it presents a high prevalence of occlusion both in the immediate postoperative period and in the long-term follow-up. Aspirin plays a well-established role in this setting, and for a long time, clopidogrel use has been restricted to patients allergic to aspirin. Recently, subgroup analyses of studies with different anti-platelet therapies have shown reduced mortality and cardiovascular events in patients on dual anti-platelet antiplatelet therapy (DAPT) undergoing CABG, although such studies have not been designed to evaluate this patient profile. However, there is still an insufficient number of randomized studies using DAPT in this context, resulting in a disagreement between the European and American cardiology societies guidelines regarding their indication and generating doubts in clinical practice.

RESUMO A cirurgia de revascularização miocárdica (CRM) é tratamento fundamental em pacientes com doença arterial coronariana (DAC) tanto para controle de sintomas quanto para melhora do prognóstico. A patência dos enxertos venosos ainda hoje é o ponto mais vulnerável do tratamento cirúrgico, por apresentar alta prevalência de oclusão tanto no pós-operatório imediato como no seguimento em longo prazo. A aspirina tem papel bem estabelecido neste cenário e, por muito tempo, o uso do clopidogrel ficou restrito a pacientes alérgicos a aspirina. Recentemente, análises de subgrupos de estudos com diferentes terapias antiplaquetárias demonstraram redução de mortalidade e eventos cardiovasculares em pacientes em uso de dupla antiagregação plaquetária (Dapt) submetidos à CRM, ainda que tais estudos não tenham sido desenhados para avaliar este perfil de pacientes. Contudo, há ainda uma quantidade insuficiente de estudos randomizados com uso de Dapt nesse contexto, resultando em uma discordância entre as diretrizes europeia e americana de cardiologia quanto à sua indicação e gerando dúvidas na prática clínica.

Impact of Baseline Bleeding Risk on Efficacy and Safety of Ticagrelor versus Clopidogrel in Chinese Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention / 中华医学杂志(英文版)

Background@#There was still conflict on the antithrombotic advantage of ticagrelor versus clopidogrel among East Asian population with acute coronary syndrome (ACS). We considered that the baseline bleeding risk might be an undetected key factor that significantly affected the efficacy of ticagrelor.@*Methods@#A total of 20,816 serial patients who underwent percutaneous coronary intervention (PCI) from October 2011 to August 2014 in the General Hospital of Shenyang Military Region were enrolled in the present study. Patients receiving ticagrelor or clopidogrel were further subdivided according to basic bleeding risk. The primary outcome was net adverse clinical events (NACEs) defined as major adverse cardiac or cerebral events (MACCE, including all-cause death, myocardial infarction, ischemia-driven target vessel revascularization, or stroke) and any bleeding during 1-year follow-up. Comparison between ticagrelor and clopidogrel was adjusted by propensity score matching (PSM).@*Results@#Among the 20,816 eligible PCI patients who were included in this study, there were 1578 and 779 patients in the clopidogrel and ticagrelor groups, respectively, after PSM, their clinical parameters were well matched. Patients receiving ticagrelor showed comparable NACE risk compared with those treated by clopidogrel (5.3% vs. 5.1%, P = 0.842). Furthermore, ticagrelor might reduce the MACCE risk in patients with low bleeding risk but increase MACCE in patients with moderate-to-high bleeding potential (ticagrelor vs. clopidogrel, low bleeding risk: 2.5% vs. 4.9%, P = 0.022; moderate-to-high bleeding risk: 4.8% vs. 3.0%, P = 0.225; interaction P = 0.021), with vast differences in all bleeding (low bleeding risk: 1.5% vs. 0.8%, P = 0.210; moderate-to-high bleeding risk: 4.8% vs. 3.0%, P = 0.002; interaction P = 0.296).@*Conclusion@#Among real-world Chinese patients with ACS treated by PCI, ticagrelor only showed superior efficacy in patients with low bleeding risk but lost its advantage in patients with moderate-to-high bleeding potential.

Uso de terapia antiagregante dual luego de angioplastía coronaria: duración, frecuencia de sangramientos y validación de scores de riesgo de hemorragia en una cohorte chilena / Dual anti platelet therapy post PTCA: duration, bleeding risk and validation of scores for predicting risk of bleeding in a Chilean population

Resumen: Introducción: La terapia antiagregante dual (TAD) con aspirina más clopidogrel o ticagrelor es fundamental para prevenir trombosis de stent y nuevos eventos cardiovasculares (CV) en pacientes sometidos a angioplastía coronaria (AC). Sin embargo, TAD se asocia a un riesgo aumentado de hemorragias, en particular cuando su uso se prolonga. Recientemente se han creado puntajes (DAPT, PRECISE-DAPT) que buscan estimar el riesgo de sangrado en pacientes con TAD por tiempo prolongado, los que quisimos evaluar en nuestra población. Métodos: Se utilizó la base de datos prospectiva de Prevención Cardiovascular del Hospital Clínico U. Católica, seleccionando pacientes sometidos a AC el año 2015. Se realizó una encuesta telefónica estandarizada para identificar episodios de sangrado definidos según clasificación ISTH, tiempo de uso de TAD y nuevos eventos CV. Se calcularon los puntajes DAPT y PRECISE-DAPT. Se usó pruebas de t de Student, test exacto de Fisher y curva ROC, según correspondiese, considerando significativa una p<0,05. Resultados: Se incluyeron 227 pacientes (edad 64,2±12,3 años, 22,5% mujeres), de los cuales el 69,6% eran hipertensos, 28,6% diabéticos, 26,9% fumadores y 5,3% insuficientes renales crónicos. En el 63% de los pacientes la AC fue por síndrome coronario agudo, se implantaron 1,4±0,7 stents/paciente y el 37% de los pacientes recibió sólo stents metálicos. Al momento de la encuesta, el seguimiento fue de 26±3 meses. Se registró un tiempo promedio de duración de TAD de 12,6±7,4 meses, con 99,1% de los pacientes recibiendo aspirina, 93,4% clopidogrel, 6,6% ticagrelor y 9,3% anticoagulantes orales. Hubo 35 (15,4%) nuevos eventos CV (revascularización 14, infarto 12, accidente cerebrovascular 2 y muerte 7) y 31 (13,6%) episodios de sangrados (criterio ISTH). De acuerdo con el criterio TIMI de sangrado se registraron 5 (2,2%) episodios graves, 9 (3,9%) leves y 17 (7,4%) menores. En 10 (4,4%) pacientes se modificó la TAD debido al sangrado. PRECISE-DAPT se asoció de manera significativa a los episodios de sangrado (p<0,01); tener un puntaje de alto riesgo (>25) aumentó más de 3 veces el riesgo de sangrado (OR 3,1 IC 1,4-7,1, p<0,01) y una curva ROC estableció que en la población estudiada el mejor punto de corte fue de 18 puntos (C-statistic 0,69) (Figuras 1A y B). El uso de TACO aumentó el riesgo (OR 3,4 IC 1,2-9,5, p=0,02). Si bien miden distintos parámetros, los puntajes de riesgo DAPT y PRECISE-DAPT se correlacionaron significativamente en nuestra cohorte (p<0,01). Conclusiones: En esta cohorte de la vida real se demuestra que la ocurrencia de sangramientos es un evento frecuente en pacientes con TAD, similar a la tasa de nuevos eventos CV, y por tanto debe ser un factor relevante a considerar al momento de la AC y la selección de la TAD. El puntaje PRECISE-DAPT es una herramienta útil para predecir sangrados, aunque nuestros resultados sugieren que en población chilena los valores de corte pueden ser algo menores que lo previamente publicado .

Abstracts: Background: Dual antiplatelet therapy (DAT) with aspirin plus clopidogrel or ticagrelor is essential for the prevention of stent thrombosis and new cardiovascular events in patients undergoing PCI. However, DAT is associated with an increased risk of bleeding, more so when it is used for prolonged time periods. Scores (DAPT, PRECISE-DAPT) developed to predict bleeding risk were evaluated in this study. Method: The prospective Cardiovascular Prevention database at Catholic University Hospital was used to select patients who underwent PCI followed by DAT during 2015. By phone contact information on bleeding episodes - according to the ISTH classification -, new cardiovascular events and DAT duration were collected. DAPT and PRECISE- DAPT scores were calculated. Student's t test, Fisher exact test and ROC analysis were used. Significance was established at p< 0.05. Results: 277 patients were included (age 64.2±12.3 y-o, 22.5% women). Hypertension was present in 66.9%, diabetes in 28.6%, smoking habit in 26.9% and renal failure in 5.3%. The indication for PCI was acute coronary syndrome in 63%, 1.4±0.7 stents per patient were implanted and 37% of patients received bare metal stents exclusively. Follow-up extended for 26±3 months. DAT was active for 12.6±7.4 months and 9.3% of patients received oral anticoagulant therapy. There were 35 (15.4%) new cardiovascular events (14 revascularizations, 12 myocardial infarctions, 2 CVA and 7 deaths). Conversely, there were 31 (13.6%) bleeding episodes. According to the TIMI classification, bleeding episodes were severe in 2.2%, mild in 3.9% and minor in 7.4%. In 4% of patients DAT was modified due to bleeding. PRECISE-DAPT score was significantly associated to bleeding episodes (p<0.01). A high score (>25) was associated with a 3-fold risk of bleeding (OR 3.1, CI 1.4-7.1 (p<0.01). Through ROC analysis the best PRECISE-DAPT cutting point in this cohort was 18 (C=0.69). The use of oral anticoagulation increased bleeding risk (OR 3.4 CI 1.2 - 9.5, p=0.02). DAPT and PRECISE-DAPT were significantly correlated (p<0.01). Conclusion: Bleeding is a frequent complication of DAT, similar to the risk of new cardiovascular events. PRECISE-DAPT score is useful to estimate the risk of bleeding, although this study suggests that in the studied population the cutting point may be somewhat lower than previously published.

Cost-effectiveness analysis of ticagrelor compared to clopidogrel for the treatment of patients with acute coronary syndrome in Colombia / Análisis de costo-efectividad del ticagrelor en comparación con el clopidogrel para el tratamiento de pacientes con síndrome coronario agudo en Colombia

Introduction: Acute coronary syndrome is one of the most frequent medical emergencies in developing countries. Objective: To determine, from the perspective of the Colombian health system, the cost-effectiveness of ticagrelor compared to clopidogrel for the treatment of patients with acute coronary syndrome. Materials and methods: We conducted a cost-effectiveness analysis from the perspective of the Colombian health system comparing ticagrelor and clopidogrel for the treatment of patients with acute coronary syndrome. To estimate the expected costs and outcomes, a Markov model was constructed in which patients could remain stable without experiencing new cardiovascular events, suffer from a new event, or die. For the baseline case, a 10-year time horizon and a discount ratio of 3% for costs and benefits were adopted. The transition probabilities were extracted from the PLATO (Platelet Inhibition and Patient Outcomes) clinical trial. Vital statistics were drawn from the Departmento Administrativo Nacional de Estadística (DANE) and additional information from Colombian patients included in the Access registry. To identify and measure resource use, a standard case was built by consulting guidelines and protocols. Unit costs were obtained from Colombian rate lists. A probabilistic sensitivity analysis was conducted in which costs were represented by a triangular distribution, and the effectiveness through a beta distribution. Results: In the base case, the additional cost per quality-adjusted life-year gained with ticagrelor was COP$ 28,411,503. The results were sensitive to changes in the time horizon and the unit cost of clopidogrel. For a willingness-to-pay equivalent to three times the Colombian per capita gross domestic product, the probability of ticagrelor being cost-effective was 75%. Conclusions: Ticagrelor is a cost-effective strategy for the treatment of patients with acute coronary syndrome in Colombia.

Introducción. El síndrome coronario agudo es una de las emergencias médicas más frecuentes en los países en desarrollo. Objetivo. Determinar, desde la perspectiva del sistema de salud colombiano, la relación de costo-efectividad del ticagrelor comparado con el clopidogrel para el tratamiento de pacientes con síndrome coronario agudo. Materiales y métodos. Se hizo un análisis de costo-efectividad desde la perspectiva del sistema de salud colombiano, comparando el ticagrelor y el clopidogrel para el tratamiento de pacientes con síndrome coronario agudo. Para estimar los costos y resultados esperados de las dos alternativas, se construyó un modelo de Markov en el cual los pacientes podían permanecer estables sin experimentar nuevos eventos cardiovasculares, sufrir de un nuevo evento coronario o morir. Para el caso de base, se adoptó un horizonte temporal de 10 años y una tasa de descuento de 3 % para los costos y beneficios. Las probabilidades de transición se extrajeron del estudio Platelet Inhibition and Patient Outcomes , PLATO. Las estadísticas vitales se consultaron en informes del Departamento Administrativo Nacional de Estadística (DANE) y los parámetros adicionales del modelo se basaron en la información de los pacientes colombianos incluidos en el registro en Access. Para identificar y medir el uso de recursos, se construyó un caso estándar a partir de guías y protocolos. Los costos unitarios se obtuvieron de manuales tarifarios colombianos. Se hizo un análisis de sensibilidad probabilístico en el que los costos se representaron por una distribución triangular y, las probabilidades de transición, mediante una distribución beta. Resultados. En el caso de base, el costo adicional por años de vida ajustados por calidad ganados con el ticagrelor fue de COP$ 28´411.503. Los resultados fueron sensibles a los cambios en el horizonte temporal y al costo unitario del clopidogrel. Para un umbral de costo-efectividad equivalente a tres veces el producto interno bruto per cápita de Colombia, la probabilidad de que el ticagrelor fuera costo-efectivo fue de 75 %. Conclusiones. El ticagrelor es una estrategia costo-efectiva para el tratamiento de los pacientes con síndrome coronario agudo en Colombia.

Ticagrelor en el síndrome coronario agudo. Explicando lo inexplicable / [Ticagrelor in acute coronary syndrome. Explaining the inexplicable]

The PLATO study evaluated the efficacy of adding ticagrelor, instead of clopidogrel, to aspirin in patients with acute coronary syndrome, which showed surprisingly positive results making the drug acceptable to regulatory agencies and specialty societies worldwide. Notwithstanding the aforementioned success, contradictory information supplied by critical analysis was submitted by the sponsor. The controversial findings revealed several aspects that are difficult to explain, threatening the veracity of the study’s conclusions. Mortality rate pattern, excessive benefit not comparable to prior studies, unexplained loss of follow-up development and inconsistency in findings in accordance with the country, the type of events arbitrator and monitoring committee are some of the most questionable issues. Dubious reaction to this trial is based on the fact that the information could not be found in published articles. This complex situation poses a challenge to the critical analysis of the text and raises questions as to how far the conflicts of financial interest influenced the development of the study, the communication of its results and probably, acceptance of the drug for commercial use.