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.

Evidencias para el uso combinado de ácido acetilsalicílico (aspirina) y clopidogrel en síndromes coronarios agudos / Evidences about combination use of acetylsalicylic acid (aspirin) and clopidogrel in acute coronary syndrome

Las enfermedades tromboembólicas siguen siendo una de las causas más importantes de morbilidad y mortalidad en todo el mundo. El mecanismo fisiopatológico subyacente en los síndromes coronarios agudos es la trombosis coronaria. Por eso, la base de su tratamiento se ha centrado en los fármacos antiplaquetarios, fibrinolíticos y anticoagulantes. En un número importante de individuos deben emplearse medidas adicionales como, por ejemplo, el intervencionismo percutáneo coronario (angioplastia y la colocación de los llamados stentsintracoronarios). La aspirina se ha considerado como el fármaco de primera elección en la prevención de las afecciones tromboembólicas. La combinación aspirina-clopidogrel ha representado una terapéutica sumamente eficiente en el tratamiento de los eventos tromboembólicos. La introducción de tabletas de combinación fija representa un avance para facilitar el cumplimiento de la terapia.

Thromboembolic diseases remain one of the most important causes of morbidity and mortality worldwide. The pathophysiologic mechanism underlying the acute coronary syndromes is coronary thrombosis. That is why the basis of its treatment has focused on antiplatelet, fibrinolytic and anticoagulant drugs. In a significant number of individuals, additional measures must be used, such as, for example, the coronary percutaneous intervention (angioplasty and placement of the so-called intracoronary stents). Aspirin has been regarded as the drug of first choice in the prevention of thromboembolic diseases. The combination aspirin-clopidogrel has represented a highly efficient therapeutic measure for thromboembolic events. The introduction of fixed combination tablets represents a step forward in order to facilitate therapeutic compliance.

Decreased platelet responsiveness to clopidogrel correlates with CYP2C19 and PON1 polymorphisms in atherosclerotic patients

Clopidogrel and aspirin are the most commonly used medications worldwide for dual antiplatelet therapy after percutaneous coronary intervention. However, clopidogrel hyporesponsiveness related to gene polymorphisms is a concern. Populations with higher degrees of genetic admixture may have increased prevalence of clopidogrel hyporesponsiveness. To assess this, we genotyped CYP2C19, ABCB1, and PON1 in 187 patients who underwent percutaneous coronary intervention. Race was self-defined by patients. We also performed light transmission aggregometry with adenosine diphosphate (ADP) and arachidonic acid during dual antiplatelet therapy. We found a significant difference for presence of the CYP2C19*2 polymorphism between white and non-white patients. Although 7% of patients had platelet resistance to clopidogrel, this did not correlate with any of the tested genetic polymorphisms. We did not find platelet resistance to aspirin in this cohort. Multivariate analysis showed that patients with PON1 and CYP2C19 polymorphisms had higher light transmission after ADP aggregometry than patients with native alleles. There was no preponderance of any race in patients with higher light transmission aggregometry. In brief, PON1 and CYP2C19 polymorphisms were associated with lower clopidogrel responsiveness in this sample. Despite differences in CYP2C19 polymorphisms across white and non-white patients, genetic admixture by itself was not able to identify clopidogrel hyporesponsiveness.

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.

Time-To-Treatment of Acute Coronary Syndrome and Unit of First Contact in the ERICO Study / Tempo para Tratamento durante Síndrome Coronariana Aguda e Unidade de Primeiro Contato no Estudo ERICO

Abstract Background: To the best of our knowledge, there are no studies evaluating the influence of the unit of the first contact on the frequency and time of pharmacological treatment during an acute coronary syndrome (ACS) event. Objectives: The main objective was to investigate if the unit of first contact influenced the frequency and time of aspirin treatment in the Strategy of Registry of Acute Coronary Syndrome (ERICO) study. Methods: We analyzed the pharmacological treatment time in 830 ERICO participants - 700 individuals for whom the hospital was the unit of first contact and 130 who initially sought primary care units. We built logistic regression models to study whether the unit of first contact was associated with a treatment time of less than three hours. Results: Individuals who went to primary care units received the first aspirin dose in those units in 75.6% of the cases. The remaining 24.4% received aspirin at the hospital. Despite this finding, individuals from primary care still had aspirin administered within three hours more frequently than those who went to the hospital (76.8% vs 52.6%; p<0.001 and 100% vs. 70.7%; p=0.001 for non ST-elevation ACS and ST-elevation myocardial infarction, respectively). In adjusted models, individuals coming from primary care were more likely to receive aspirin more quickly (odds ratio: 3.66; 95% confidence interval: 2.06-6.51). Conclusions: In our setting, individuals from primary care were more likely to receive aspirin earlier. Enhancing the ability of primary care units to provide early treatment and safe transportation may be beneficial in similar settings.

Resumo Fundamento: Em nosso conhecimento, não há estudos que avaliam a influência da unidade de primeiro contato na frequência e tempo para o tratamento farmacológico durante um evento de síndrome coronariana aguda (SCA). Objetivos: O principal objetivo foi investigar se a unidade de primeiro contato influencia a frequência e o tempo para tratamento com aspirina no estudo "Estratégia de Registro de Insuficiência Coronariana" (ERICO). Métodos: Analisamos o tempo para o tratamento farmacológico em 830 participantes do estudo ERICO - 700 indivíduos cuja primeira unidade de contato foi o hospital, e 130 que procuraram, num primeiro momento, unidades de atenção primária. Construímos modelos de regressão logística para estudar se a unidade de primeiro contato estava associada a um tempo de tratamento de menos de três horas. Resultados: Indivíduos que buscaram unidades de atenção primária receberam a primeira dose de aspirina nestas unidades em 75,6% dos casos. Os outros 24,4% receberam a aspirina no hospital. Apesar deste achado, indivíduos de unidades de atenção primária receberam aspirina em três horas mais frequentemente do que aqueles que foram ao hospital (76,8% vs 52,6%; p<0,001 e 100% vs, 70,7%; p=0,001 para SCA sem elevação do segmento ST e infarto agudo do miocárdio com elevação do ST, respectivamente). Em modelos ajustados, indivíduos vindos de unidades de atenção primária tinham mais probabilidade de receber aspirina mais rapidamente (razão de chances: 3,66; 95% intervalo de confiança: 2,06-6,51). Conclusões: Neste contexto, indivíduos provenientes de unidades de atenção primária tinham maior chance de receber aspirina mais rapidamente. O aprimoramento da capacidade das unidades de atenção primária para proporcionar tratamento precoce e transporte seguro pode ser benéfico em contextos similares.

Clopidogrel use after myocardial revascularization: prevalence, predictors, and one-year survival rate

Abstract Introduction: Antiplatelet therapy after coronary artery bypass graft (CABG) has been used. Little is known about the predictors and efficacy of clopidogrel in this scenario. Objective: Identify predictors of clopidogrel following CABG. Methods: We evaluated 5404 patients who underwent CABG between 2000 and 2009 at Duke University Medical Center. We excluded patients undergoing concomitant valve surgery, those who had postoperative bleeding or death before discharge. Postoperative clopidogrel was left to the discretion of the attending physician. Adjusted risk for 1-year mortality was compared between patients receiving and not receiving clopidogrel during hospitalization after undergoing CABG. Results: At hospital discharge, 931 (17.2%) patients were receiving clopidogrel. Comparing patients not receiving clopidogrel at discharge, users had more comorbidities, including hyperlipidemia, hypertension, heart failure, peripheral arterial disease and cerebrovascular disease. Patients who received aspirin during hospitalization were less likely to receive clopidogrel at discharge (P≤0.0001). Clopidogrel was associated with similar 1-year mortality compared with those who did not use clopidogrel (4.4% vs. 4.5%, P=0.72). There was, however, an interaction between the use of cardiopulmonary bypass and clopidogrel, with lower 1-year mortality in patients undergoing off-pump CABG who received clopidogrel, but not those undergoing conventional CABG (2.6% vs 5.6%, P Interaction = 0.032). Conclusion: Clopidogrel was used in nearly one-fifth of patients after CABG. Its use was not associated with lower mortality after 1 year in general, but lower mortality rate in those undergoing off-pump CABG. Randomized clinical trials are needed to determine the benefit of routine use of clopidogrel in CABG.

When is the Best Time for the Second Antiplatelet Agent in Non-St Elevation Acute Coronary Syndrome? / Qual o Melhor Momento para o Segundo Antiplaquetário na Síndrome Coronariana Aguda sem Elevação do ST?

Abstract Dual antiplatelet therapy is a well-established treatment in patients with non-ST elevation acute coronary syndrome (NSTE-ACS), with class I of recommendation (level of evidence A) in current national and international guidelines. Nonetheless, these guidelines are not precise or consensual regarding the best time to start the second antiplatelet agent. The evidences are conflicting, and after more than a decade using clopidogrel in this scenario, benefits from the routine pretreatment, i.e. without knowing the coronary anatomy, with dual antiplatelet therapy remain uncertain. The recommendation for the upfront treatment with clopidogrel in NSTE-ACS is based on the reduction of non-fatal events in studies that used the conservative strategy with eventual invasive stratification, after many days of the acute event. This approach is different from the current management of these patients, considering the established benefits from the early invasive strategy, especially in moderate to high-risk patients. The only randomized study to date that specifically tested the pretreatment in NSTE-ACS in the context of early invasive strategy, used prasugrel, and it did not show any benefit in reducing ischemic events with pretreatment. On the contrary, its administration increased the risk of bleeding events. This study has brought the pretreatment again into discussion, and led to changes in recent guidelines of the American and European cardiology societies. In this paper, the authors review the main evidence of the pretreatment with dual antiplatelet therapy in NSTE-ACS.

Resumo A indicação de dupla terapia antiplaquetária para o tratamento da síndrome coronariana aguda sem elevação do ST está bem estabelecida e é recomendação classe I (Nível de Evidência A) nas atuais diretrizes nacionais e internacionais. No entanto, essas mesmas diretrizes não são muito claras e consensuais quanto ao melhor momento para utilização do segundo antiplaquetário. As evidências sobre este tema são conflitantes e, após mais de uma década do uso do clopidogrel neste cenário, ainda há discussão se o pré-tratamento com dupla terapia antiplaquetária teria benefício de maneira rotineira, ou seja, quando aplicada sem conhecer a anatomia coronária. A recomendação de tratamentoupfront com clopidogrel na síndrome coronariana aguda sem elevação do ST se baseia em redução de eventos não fatais identificados em estudos que utilizavam estratégia conservadora, com eventual estratificação invasiva tardia, vários dias após o evento agudo. Essa abordagem é bastante diferente da que é feita atualmente, tendo em vista os benefícios já demonstrados da estratégia invasiva precoce nos pacientes de risco intermediário/alto. O único ensaio clínico randomizado que testou a hipótese do pré-tratamento na síndrome coronariana aguda sem elevação do ST sob a atual estratégia invasiva precoce utilizou o antiplaquetário prasugrel e mostrou que não houve benefício em redução de eventos isquêmicos, tendo, por outro lado, aumentado o risco de eventos hemorrágicos. Este estudo trouxe novamente o pré-tratamento à discussão e modificou recomendações nas atuais diretrizes das sociedades americana e europeia de cardiologia. Neste artigo, os autores apresentam uma revisão sobre as principais evidências do pré-tratamento com dupla terapia antiplaquetária na síndrome coronariana aguda sem elevação do ST.

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.

Clopidogrel versus prasugrel en síndrome coronario agudo tratado con angioplastia / Clopidogrel versus prasugrel in acute coronary syndrome treated with coronary angioplasty

Al uso del clopidogrel se han agregado nuevos antiagregantes como prasugrel y ticagrelor. El objetivo de este estudio fue comparar la incidencia de eventos isquémicos y hemorrágicos en pacientes que han recibido clopidogrel o prasugrel.Se incluyeron de manera consecutiva todos los pacientes con angioplastia durante la internación por síndrome coronario agudo entre diciembre 2011 y diciembre 2012.Fueron incluidos 398 pacientes. No se observaron diferencias en la mortalidad de causa cardiovascular (clopidogrel 2.5% vs. prasugrel 2.9%, p = 0.48). El grupo prasugrel presentó una reducción en la tasa de infarto (1.9% vs. 6.8%, p = 0.01) con sangrado totales (18.5% vs. 8.5%, p = 0.001) a expensas de sangrados menores (12.4% vs. 3.4%, p < 0.001), sin diferencia en sangrados mayores (p = 0.27) y sangrados con peligro de vida (p =.0.20). Por análisis multivariado los predictores independientes de mortalidad cardiovascular fueron edad (odds ratio 1.08, intervalo de confianza, IC, 95% 1.02-1.16, p = 0.02) insuficiencia renal (odds ratio 6.98, IC 95% 1.23-39.71, p < 0.0001). En cuanto al sangrado total se identificaron la edad (odds ratio 1.06, IC 95% 1.02-1.09, p = 0.002), elevación del segmento ST (odds ratio 1.99, IC 95% 1.05-3.79, p = 0.02), insuficiencia renal (odds ratio 3.32, IC 95% 1.62-6.78, p = 0.002) y utilización de prasugrel (odds ratio 3.97, IC 95% 1.87-8.41, p < 0.0001). La utilización de prasugrel se asocia a una menor tasa de infarto agudo de miocardio al año de seguimiento, con incremento de hemorragias menores. No se observaron diferencias significativas en la mortalidad cardiovascular entre ambos grupos.

Greater antithrombotic potency new antiplatelet agents have been added such as prasugrel (PR) and ticagrelor to the traditional use of clopidogrel (CL) in the treatment of acute coronary syndrome (ACS). This study was aimed at comparing the incidence of long term ischemic and hemorrhagic events in patients treated with CL or PR during hospitalization. Retrospective ACS data base analysis performed by our cardiology service was completed prospectively. There were consecutively included all patients with percutaneous coronary intervention (PCI) during hospitalization due to ACS from December 2011 thru December 2012. A total of 398 ACS patients who underwent PCI with stent implantation were recruited. No differences in cardiovascular related deaths were observed in both groups (PR 2.9% vs. CL 2.5%, p = 0.48). PR group showed less re-infraction (1.9% vs. 6.8%, p = 0.01) with more total bleedings (18.5% vs. 8.5%, p = 0.001) and minor bleedings (12.4% vs. 3.4%, p < 0.001) with no differences in major and life threatening bleedings (p = ns). Multivariate analysis showed that independent predictors of cardiovascular mortality were age (OR 1.08, CI 95% 1.02-1.16) and renal failure (OR 6.98, CI 95% 1.23-39.71). Independent predictors for total bleeding were age (OR 1.06, CI 95% 1.02-1.09),ST segment elevation myocardial infarction (OR 1.99, CI 95% 1.05-3.79), renal failure (OR 3.32, CI 95% 1.62-6.78) and prasugrel use (OR 3.97, CI 95% 1.87-8.41). Use of prasugrel, in the ACS that requires PCI with stent, is associated with a lower myocardial infarction a year after follow-up, and it also leads to an increase of milder hemorrhage. No significant differences were observed in the cardiovascular mortality of both groups.

Effects of simvastatin/ezetimibe on microparticles, endothelial progenitor cells and platelet aggregation in subjects with coronary heart disease under antiplatelet therapy

It is not known whether the addition of ezetimibe to statins adds cardiovascular protection beyond the expected changes in lipid levels. Subjects with coronary heart disease were treated with four consecutive 1-week courses of therapy (T) and evaluations. The courses were: T1, 100 mg aspirin alone; T2, 100 mg aspirin and 40 mg simvastatin/10 mg ezetimibe; T3, 40 mg simvastatin/10 mg ezetimibe, and 75 mg clopidogrel (300 mg initial loading dose); T4, 75 mg clopidogrel alone. Platelet aggregation was examined in whole blood. Endothelial microparticles (CD51), platelet microparticles (CD42/CD31), and endothelial progenitor cells (CD34/CD133; CDKDR/CD133, or CD34/KDR) were quantified by flow cytometry. Endothelial function was examined by flow-mediated dilation. Comparisons between therapies revealed differences in lipids (T2 and T3<T1 and T4 for total cholesterol, LDL-C, and triglycerides; P<0.002 for all), as well as for endothelial function (T2>T1 and T4, P=0.001). Decreased platelet aggregation was observed after aspirin (arachidonic acid, T1<T3 and T4, P=0.034) and clopidogrel (adenosine, T3 and T4<T1 and T2, P<0.0001) therapy. Simvastatin/ezetimibe diphosphate did not change platelet aggregation, the amount of circulating endothelial and platelet microparticles, or endothelial progenitor cells. Cardiovascular protection following therapy with simvastatin/ezetimibe seems restricted to lipid changes and improvement of endothelial function not affecting the release of microparticles, mobilization of endothelial progenitor cells or decreased platelet aggregation.

Farmacogenómica cardiovascular / Cardiovascular pharmacogenomics

La enfermedad cardiovascular representa la primera causa de morbimortalidad a nivel mundial. Actualmente, la evidencia que sustenta la implementación de determinadas intervenciones terapéuticas se origina a partir de datos provenientes de grupos poblacionales. Sin embargo, los pacientes presentan variaciones interindividuales relacionadas tanto con la eficacia como con la toxicidad ante un mismo tratamiento farmacológico. Estas variaciones pueden ser explicadas principalmente por diferencias en la adherencia, interacciones no reconocidas y diferencias genéticas. Las alteraciones en el genoma explican entre un 20 y un 95% de la variabilidad interindividual tanto en la disponibilidad como en la respuesta a fármacos. En el tratamiento de las enfermedades cardiovasculares existen diversos ejemplos de dicha variabilidad genética interindividual y su impacto en la eficacia o toxicidad de diferentes fármacos. La variabilidad genética que determina la respuesta al clopidogrel radica fundamentalmente en el polimorfismo del citocromo (CYP) 2C19. Los polimorfismos en los genes CYP 2C9 y VKORC1 explican gran parte de la variabilidad en la respuesta a los anticoagulantes dicumarínicos. Con respecto al tratamiento hipolipidemiante, el polimorfismo del gen SLCO1B1 se ha asociado a la aparición de miopatía en pacientes tratados con simvastatina. Muchos otros polimorfismos han sido postulados pero sin un impacto clínico definido hasta la fecha. La utilización de la farmacogenómica en la práctica cotidiana ofrece la oportunidad de poder predecir toxicidad o eficacia terapéutica.

Cardiovascular disease remains a major cause of morbidity and mortality worldwide. Current medical practice takes into account information based on population studies and benefits observed in large populations or cohorts. However, individual patients present great differences in both toxicity and clinical efficacy that can be explained by variations in adherence, unknown drug to drug interactions and genetic variability. The latter seems to explain from 20% up to 95% of patient to patient variability. Treating patients with cardiovascular disorders faces the clinician with the challenge to include genomic analysis into daily practice. There are several examples within cardiovascular disease of treatments that can vary in toxicity or clinical usefulness based on genetic changes. One of the main factors affecting the efficacy of Clopidogrel is the phenotype associated with polymorphisms in the gene CYP 2C9. Furthermore, regarding oral anticoagulants, changes in CYP2C9 and VKORC1 play an important role in changing the clinical response to anticoagulation. When analyzing statin treatment, one of their main toxicities (myopathy) can be predicted by the SLCO1B1 polymorphism. The potential for prediction of toxicity and clinical efficacy from the use of genetic analysis warrants further studies aiming towards its inclusion in daily clinical practice.

Alta reatividade plaquetária durante tratamento é preditora de eventos cardíacos em pacientes com stents farmacológicos / High on-treatment platelet reactivity predicts cardiac events in patients with drug-eluting stents

FUNDAMENTO: O papel dos testes de reatividade plaquetária (RP) na predição de eventos em longo prazo em pacientes latino-americanos tratados com stents farmacológicos (SF) não foi estabelecido. OBJETIVOS: Analisar o papel dos testes de RP na predição de eventos após a implantação de SF. MÉTODOS: De maio de 2006 a janeiro de 2008, foram incluídos 209 pacientes brasileiros que se submeteram a tratamento eletivo com SF. A RP foi avaliada 12 a 18 horas após o procedimento, por agregometria de transmitância de luz com 5µM de ADP. Os pacientes foram acompanhados prospectivamente por até 4,8 anos. Dezessete (8%) dos indivíduos foram perdidos durante o acompanhamento e a coorte final foi composta de 192 pacientes. A curva ROC foi utilizada para determinar o melhor ponto de corte de 5µM de ADP para prever eventos. O endpoint primário foi uma combinação de morte cardiovascular, infarto agudo do miocárdio, trombose definitiva de stent, e revascularização de artéria alvo.Modelos de risco proporcional de Cox foram utilizados para determinar as variáveis independentemente associadas com o tempo até o primeiro evento. RESULTADOS: O melhor ponto de corte de 5µM de ADP foi de 33%. Cento e sete (55,7%) pacientes apresentaram 5mM de ADP > 33%. A taxa de sobrevivência livre de eventos em 1.800 dias foi de 55% contra 70% para os indivíduos com ADP5 acima e abaixo desse ponto de corte, respectivamente (p = 0,001). Preditores de tempo independentes para o primeiro evento foram tabagismo atual (HR 3,49, IC95%: 1,76-6,9, p = 0,0003), ADP 5mM > 33% (HR 1,95, IC95%: 1,09-3,51, p = 0,025) e idade (HR 1,03 IC 95%: 1,0-1,06, p = 0,041). CONCLUSÕES: Neste estudo, 55,7% dos pacientes apresentaram alta reatividade plaquetária durante tratamento. 5µM de ADP > 33% foi um preditor independente de eventos em longo prazo.

BACKGROUND: The role of platelet reactivity (PR) tests in the prediction of long-term events in Latin-American patients treated with drug-eluting stents (DES) has not been established. OBJECTIVES: To assess the role of PR tests in the prediction of events after DES implantation. METHODS: From May 2006 through January 2008, 209 Brazilian patients who underwent elective treatment with DES were included. PR was assessed 12 to 18h after the procedure by light transmittance aggregometry with 5µM of ADP. Patients were prospectively followed for up to 4.8 years. Seventeen (8%) individuals were lost to follow-up and the final cohort comprised 192 patients. Receiver operating curve (ROC) was used to determine the best 5µM of ADP cutoff to predict events. The primary endpoint was a combination of cardiovascular death, acute myocardial infarction, definite stent thrombosis, and target-artery revascularization. Cox proportional hazard models were used to determine the variables independently associated with the time to the first event. RESULTS: The best ADP 5µM cutoff was 33%. One hundred and seven (55.7%) patients had ADP 5µM >33%. Event-free survival rate at 1,800 days was 55% vs. 70% for individuals with ADP5 above and below such cutoff, respectively (p=0.001). Independent predictors of time to first event were current smoking (HR 3.49; 95% CI 1.76-6.9; p=0.0003), ADP 5µM >33% (HR 1.95; 95% CI 1.09-3.51; p=0.025) and age (HR 1.03; 95% CI 1.0-1.06; p=0.041). CONCLUSIONS: In this study, 55.7% of the patients had high on-treatment platelet reactivity. ADP 5µM >33% was an independent predictor of long-term events.

Desensibilización rápida en pacientes con hipersensibilidad a aspirina sometidos a angioplastía coronaria: Reporte de cuatro casos / Rapid aspirin desensitization in patients with a history of aspirin hypersensitivity requiring coronary angioplasty: Report of four cases

Background: Aspirin use is necessary after a coronary angioplasty. It should not be used in patients with a history of hypersensitivity. However, rapid desensitization protocols have been reported to allow its use in such patients. One of these protocols consists in the administration of progressive doses of aspirin, from 1 to 100 mg in a period of 5.5 hours, in a controlled environment. We report four male patients aged 45,49, 59 and 73 years with a history of aspirin hypersensitivity, who were subjected to a coronary angioplasty. In all, the rapid aspirin desensitization protocol was successfully applied, allowing the use of the drug after the intervention without problems.

Resistência ao clopidogrel: prevalência e variáveis associadas / Resistance to clopidogrel: prevalence and associate variables

FUNDAMENTO: A dupla terapia antiagregante plaquetária com ácido acetilsalicílico e clopidogrel é pedra angular do tratamento de pacientes submetidos a angioplastia com implante de stents coronarianos. Todavia, parte desses pacientes, a despeito do uso de aspirina e clopidogrel, não se encontram eficazmente antiagregados, fenômeno conhecido como resistência aos antiagregantes plaquetários. A sua prevalência, assim como as condições a ela relacionadas são desconhecidas em nosso meio. OBJETIVO: Determinar a prevalência de resistência ao clopidogrel, assim como as variáveis a ela relacionadas. MÉTODOS: Pacientes admitidos para angioplastia eletiva em uso crônico de aspirina e clopidogrel entre janeiro de 2007 e janeiro de 2010. Uma hora após o procedimento, foi medida a agregação plaquetária utilizando a agregometria óptica com difosfato de adenosina 5 µmoles/l como agonista. Nesse momento, em um coorte transversal, determinou-se a prevalência de resistência ao clopidogrel, definida com um valor de agregação plaquetária > 43% e um modelo de regressão logística às variáveis a ela relacionadas. RESULTADOS: Foram analisados 205 pacientes (66,4 ± 11anos, 61,5% masculino). A prevalência de resistência ao clopidogrel foi 38,5% (IC95% 31,9 - 45,2%). O valor da glicemia (OR = 1,014 IC95% 1,004 - 1,023), infarto do miocárdio prévio (OR = 2,320 IC95% 1,1103 - 4,892) e a resposta terapêutica à aspirina (OR = 1,057 IC95% 1,017 - 1,099) foram as variavéis de associação independente à resistência ao clopidogrel. CONCLUSÃO: A prevalência de resistência ao clopidogrel foi alta. Glicemia, infarto agudo do miocárdio prévio e a resposta ao ácido acetilsalicílico foram variáveis a ela relacionadas. A melhor compreensão desse fenômeno se faz necessária frente às novas propostas de antiagregantes plaquetários.

BACKGROUND: The dual antiplatelet therapy with acetylsalicylic acid (ASA) and clopidogrel is the cornerstone of treatment for patients undergoing angioplasty with coronary stent implantation. However, some of these patients, despite the use of aspirin and clopidogrel, are not effectively anti-aggregated, a phenomenon known as resistance to antiplatelet agents. Its prevalence, as well as the conditions associated with it, is unknown in our country. OBJECTIVE: To determine the prevalence of clopidogrel resistance, as well as variables associated with it. METHODS: Patients admitted for elective angioplasty in chronic use of ASA and clopidogrel between January 2007 and January 2010 were studied. One hour after the procedure, platelet aggregation was measured using optical aggregometry with adenosine diphosphate 5 mmoles / l as agonist. At that moment, in a cross-sectional cohort, we determined the prevalence of clopidogrel resistance, defined as the value of platelet aggregation > 43% and a logistic regression model to the variables associated with it. RESULTS: A total of 205 patients were analyzed (66.4 ± 11 years, 61.5% males). The prevalence of clopidogrel resistance was 38.5% (95% CI: 31.9 - 45.2%). Blood glucose (OR = 1.014; 95%CI: 1.004 - 1.023), previous myocardial infarction (OR = 2.320; 95%CI: 1.1103 - 4.892) and therapeutic response to ASA (OR = 1.057; 95%CI: 1.017 - 1.099) were the variables independently associated with clopidogrel resistance. CONCLUSION: The prevalence of clopidogrel resistance was high. Glycemia, acute myocardial infarction and response to ASA were variables associated with it. A better understanding of this phenomenon is necessary considering the new antiplatelet aggregant agents.

Terapia anticoagulante no tratamento das síndromes coronárias agudas: revisão / Anticoagulant therapy for treating acute coronary syndromes: A review

As síndromes coronarianas são responsáveis por elevado número de hospitalizações, associadas a importante morbimortalidade nos dias atuais. O tratamento de suas formas de apresentação tem sido objeto de grande interesse nas últimas décadas e, conhecida a estreita relação de sua fisiopatologia com ativação das vias da cascata de coagulação ? que em última instância resulta na formação do trombo coronariano, drogas com ação anticoagulante vêm sendo amplamente testadas em associação com a terapia antiagregante plaquetária. Algumas classes de drogas trouxeram, ao longo dos anos, benefício indubitável em relação à melhora do desfecho clínico dos pacientes e outras ainda necessitam de evidências adicionais para a implementação na prática clínica. Apesar do benefício clínico na redução de eventos adversos, é certo que o preço cobrado por essas associações tem sido o aumento significativo do risco de eventos hemorrágicos. Atualmente, as classes de anticoagulantes com benefício clínico mais amplamente aceito pela literatura nas síndromes coronarianas agudas são as heparinas não fracionadas e de baixo peso molecular e, mais recentemente, a inibição específica do fator Xa com o fondaparinux, além dos inibidores diretos da trombina alguns ainda em fase inicial de investigação. O objetivo desta revisão é discorrer sobre as recomendações de utilização das terapias anticoagulantes nas síndromes coronárias agudas, à luz dos achados dos estudos mais relevantes sobre cada uma delas e dos consensos sobre a abordagem das mesmas.

Coronary syndromes account for a high number of hospital admissions and have been associated with significant rates of morbimortality. Treatment of the outward signs of the disease has been object of great interest over the last decades. Given the great association of the disease physiopathology with the activation of the coagulation cascade pathways which eventually results in the formation of coronary thrombus, anticoagulant drugs have been widely tested in association with platelet anti-aggregation therapy. Some of such drugs have undoubtedly contributed to the clinical outcome of patients and some other still need further testing before implementation in the medicalpractice. Despite the clinical benefit of reducing adverse events, the use of such drugs has significantly increased the risk of bleeding events. According to the literature on acute coronary syndromes, the classes of anticoagulants with widely accepted clinical benefits are unfractionated and low molecular weight heparins and, more recently, fondaparinux for specific inhibition of activated X factor, besides direct thrombin inhibitors some still in early stages of testing. This review aims to argue about the recommendations of adopting anticoagulant therapies to treat acute coronary syndromes in the light of the most relevant studies on each therapy and the most consensual understandings of their approach.

Antiplaquetários nas síndromes coronarianas agudas: revisão / Antiplatelet drugs for treating acute coronary syndromes: A review

As síndromes coronarianas agudas sem supradesnivelamento do segmento ST são causadas, na maioria das vezes, por instabilização ou ruptura da placa de ateroma, com consequente formação de trombo não oclusivo. A escolha adequada de antiplaquetários é fundamental no tratamento, com redução dos eventos isquêmicos e da mortalidade. O objetivo deste artigo é a revisão crítica atualizada dos principais agentes antiplaquetários disponíveis para uso no Brasil, os mecanismos de ação de cada droga, bem como suas indicações e contraindicações em pacientes com síndrome coronariana aguda sem supradesnivelamento do segmento ST. A aspirina, isoladamente, é capaz de reduzir eventos de forma significativa. Sua associação com derivados tienopiridínicos, principalmente com o clopidogrel, acarretou sinergismo de ação com importante redução de eventos adversos. Novas drogas surgiram, gerando redução de recorrência de infarto e aumento nas taxas de sangramento, tornando mais complexa a escolha de antiplaquetários. O prasugrel, na sala de hemodinâmica, é opção basicamente nos pacientes que não receberam clopidogrel e que se submetem à angioplastia precoce, com baixo risco de sangramento avaliado por escores. O ticagrelor é uma opção ao clopidogrel para pacientes submetidos a tratamento invasivo, com possível benefício adicional na mortalidade. A escolha de antiplaquetários deve ser individualizada, conforme as circunstâncias definidas no texto, conforme o perfil de risco hemorrágicoe também conforme o perfil de risco de morte ou infarto do paciente.

Acute coronary syndromes without ST segment elevation are usually caused by destabilization or rupture of the atheroma plaque and the subsequent formation of non-occlusive thrombus. The right choice of antiplatelet drugs is crucial for treatment and to reduce both ischemicevents and mortality. This paper provides an updated critical review of the main antiplatelet drugs available in Brazil, describing the mechanisms of action, indications and contraindications of each drug for patients with acute coronary syndrome without ST segment elevation.Aspirin alone is capable of reducing events significantly. Its association with thienopyridine derivatives, especially with clopidogrel leads to synergisms and meaningful reduction of adverse events. Choosing the most adequate antiplatelet drug has become increasingly difficultas new drugs have been developed, which have reduced infarction recurrence but increased bleeding rates. Prasugrel is basically an option for patients that have not been treated with clopidogrel and undergo angioplasty in early stages, with low risks of bleeding as assessedthrough scores. Ticagrelor is an alternative to clopidogrel for patients that have undergone invasive treatment. The choice of antiplatelet drugs should be individualized for each patient, according to circumstances herein described, and according to patients? death and bleeding risk rankings.

Similar observed CABG related bleeding complications in patients with and without clopidogrel loading doses / Complicaciones hemorrágicas asociadas a cirugía de revascularización miocárdica en pacientes con o sin dosis de carga de clopidogrel

Objective: Pretreatment with clopidogrel before percutaneous coronary intervention improves cardiovascular outcomes. However, some patients require elective coronary artery bypass graft (CABG) surgery instead, possibly increasing bleeding complications. We sought to assess the hemorrhagic complications and the length of hospital stay of stable patients receiving clopidogrel pretreatment that are referred for CABG. Methods: Between March and August 2007, 493 patients underwent diagnostic catheterization; 54 patients underwent elective CABG and were stratified according to clopidogrel loading dose (n = 20) or not (n = 34). Incidences of major hemorrhagic events and median post-surgical hospital stay were compared between groups. Results: TIMI Bleeding Index was not significantly different between the clopidogrel and no-clopidogrel groups (mean difference 0.46; 95% CI -0.89 to 1.82; p = 0.5). The incidence of major TIMI bleeding (70% vs. 73.5%; p > 0.9), peak hemoglobin loss > 5 g/dL (60% vs. 38.2%; p = 0.2), and blood transfusion > 4 units (20% vs. 26.5%; p = 0.7) in clopidogrel vs. no-clopidogrel group were not statistically different. Interestingly, the post-surgical length of stay was longer for the no-clopidogrel group (median of 5 vs. 7 days; p = 0.006). Conclusion: There was no significant evidence of increased bleeding or need for blood transfusion during CABG in patients pretreated with clopidogrel. The current practice of clopidogrel pretreatment before percutaneous coronary intervention does not significantly increase the risk of hemorrhagic complications in stable patients provided they can wait for at least 7 days before CABG. In a single center retrospective study, clopidogrel pretreatment was not found to be associated with increased bleeding or need for blood transfusion during coronary artery bypass graft surgery, suggesting that clopidogrel pretreatment before percutaneous coronary intervention does not significantly increase the risk of hemorrhagic complications in stable patients provided they can wait for 7 days before the surgery.

Objetivo: El pretratamiento con clopidogrel antes de la intervención precutánea coronaria, mejora los resultados cardiovasculares. Sin embargo, algunos pacientes que requieren cirugía programada de puente aortocoronario (CABG), posiblemente incrementan las complicaciones de sangrado. Nosotros buscamos valorar las complicaciones hemorrágicas y la duración de la estancia hospitalaria de los pacientes estables que reciben el pretratamiento de clopidogrel y que son enviados a CABG. Métodos: Entre los meses de marzo y agosto de 2007, 493 pacientes tuvieron diagnóstico de cateterización; 54 pacientes tuvieron una CABG programada y fueron estratificados con base en la dosis cargada de clopidogrel (n = 20) o no cargada (n = 34), y se compararon las incidencias de mayores eventos hemorrágicos y la media de estancia post operatoria entre ambos grupos. Resultados: El Indice de Sangrado TIMI no arrojó una diferencia significativa entre los grupos con clopidogrel y sin clopidogrel (la diferencia principal 0.46; 95% CI - 0.89 a 1.82; p = 0.5). La incidencia de mayor sangrado TIMI (70 % vs. 73.5%; p > 0.9) máxima pérdida de hemoglobina > 5 g/dL (60% vs. 38.2%; p = 0.2) y transfusión de sangre > 4 unidades (20% vs. 26.5%; p = 0.7) entre los grupos con clopidogrel y sin clopidogrel no fue estadísticamente diferente. Pero es interesante que el periodo de permanencia post operatoria fue más largo en el grupo que no fue tratado con clopidogrel (media de cinco vs. siete días: p = 0.006). Conclusión: No hay una evidencia significativa de incremento de sangrado o necesidad de transfusión sanguínea durante la CABG en pacientes pretratados con clopidogrel. La práctica actual del pretratamiento clopidogrel antes de la intervención precutánea coronaria no incrementa significativamente el riesgo de complicaciones hemorrágicas en pacientes estables siempre y cuando puedan esperar al menos siete días antes de la CABG. En un estudio simple de retrospectiva, no se encontró que el pretratamiento con clopidogrel se asociara con el incremento de sangrado o la necesidad de transfusión sanguínea durante la cirugía de puente aortocoronario, sugiriendo que el pretratamiento con clopidogrel antes de la intervención precutánea coronaria, no incrementa significativamente el riesgo de complicaciones hemorrágicas en pacientes estables siempre y cuando puedan esperar siete días antes de la cirugía.