Association of CYP2C19*2 polymorphism with clopidogrel resistance among patients with high cardiovascular risk in Northeastern Mexico / Asociación del polimorfismo CYP2C19*2 con resistencia a clopidogrel en pacientes con alto riesgo cardiovascular en el noreste de México

abstract Objective: Oral antiplatelet drugs are a key to modern pharmacotherapy in cardiovascular atherothrombotic diseases. Clopidogrel (CLO) constitutes the main preventive treatment of atherothrombosis. However, a considerable inter-individual variation in CLO response has been documented, resulting in suboptimal therapy and an increased risk of recurrent adverse effects in some patients. The enzyme CYP2C19 has been reported to be the CYP isoform that activates CLO to its active metabolite. Several single nucleotide polymorphisms in the CYP2C19 gene have been identified as strong predictors of CLO-impaired pharmacological response. At least 16 variants have been associated with changes in CYP2C19 activity. Materials and Methods: The following research was composed of a total of 102 subjects with high cardiovascular risk in the northeast of Mexico, with a maintenance dose of 75 mg of CLO per day. The platelet reactivity was measured with VerifyNow P2Y12 assay, while the presence of CYP2C19*2 was identified by real-time polymerase chain reaction. Results: Patients were categorized by CYP2C19 metabolizer status based on *2 genotypes using the common consensus star allele nomenclature as normal metabolizer (G/G), intermediate metabolizer (G/A), and poor metabolizer (A/A), respectively. The phenotype frequency for CYP2C19*2 was 74.5% (G/G), 21.6% (G/A), and 3.9% (A/A). The subjects with the A allele presented ≥235 P2Y12 reaction unit levels, classifying them how poor metabolizer. The prevalence of reduced CLO effectiveness was associated with the presence of CYP2C19*2 polymorphism among Mexican patients. Conclusion: The presence of the CYP2C19*2 allele is related to resistance to the antiplatelet effect of CLO (p = 0.003).

Resumen Objetivo: Los antiplaquetarios orales son clave en la farmacoterapia moderna de las enfermedades aterotrombóticas cardiovasculares. Clopidogrel (CLO) constituye el principal tratamiento preventivo de aterotrombosis (AT). Sin embargo, se ha documentado una considerable variación interindividual en la respuesta a CLO, lo que da como resultado una terapia subóptima y mayor riesgo de efectos adversos en algunos pacientes. La enzima CYP2C19 es la isoforma CYP que activa CLO a su metabolito activo. Se han identificado varios polimorfismos de un solo nucleótido en el gen CYP2C19 como fuertes predictores de respuesta farmacológica alterada a CLO. Al menos 16 variantes se han asociado con cambios en la actividad de CYP2C19. Método: Se reclutaron un total de 102 sujetos con alto riesgo cardiovascular del noreste de México, con dosis de mantenimiento de 75 mg de CLO/día. La reactividad plaquetaria se midió con el ensayo Verify Now P2Y12, la presencia de CYP2C19*2 se identificó mediante polymerase chain reaction en tiempo real. Resultado: Los pacientes fueron clasificados por el estado metabolizador CYP2C19*2 utilizando nomenclatura consenso, como metabolizador normal (G/G), metabolizador intermedio (G/A) y metabolizador pobre (A/A), respectivamente. La frecuencia del fenotipo para CYP2C19*2 fue 74.5% (G/G), 21.6% (G/A) y 3.9% (A/A). Los sujetos con alelo A presentaron ≥235 niveles P2Y12 reaction unit, clasificándolos como metabolizadores deficientes. La prevalencia de eficacia reducida a CLO se asoció con la presencia del polimorfismo CYP2C19*2 en pacientes mexicanos. Conclusiones: La presencia del alelo CYP2C19*2 se relaciona con resistencia al efecto antiagregante plaquetario del CLO (p = 0.003).

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.

Doble terapia antiagregante en pacientes con accidente cerebrovascular isquémico agudo: Recomendación del grupo CIERTO / Dual antiplatelet therapy for secondary stroke prevention in patients with acute ischemic stroke. CIERTO group recommendation

El inicio precoz del tratamiento con antiagregantes plaquetarios es considerado el estándar de cuidado para pacientes con accidente cerebrovascular isquémico agudo. Distintos esquemas de antiagregación se han comparado con resultados que sugieren que la combinación de múltiples antiagregantes se asocian a menor riesgo de recurrencia de accidente cerebrovascular (ACV) pero a expensas de un aumento en el riesgo de sangrado, lo que a largo plazo termina opacando dichos beneficos. Sin embargo, considerando que el riesgo de recurrencia de ACV es mayor en el periodo inmediato al evento, la indicación de doble tratamiento antiagregante por tiempos limitados podría asociarse a beneficios relevantes. Con este concepto, se realizó una revisión sistemática rápida con el objetivo de evaluar el efecto del tratamiento con doble antiagregación por un periodo corto intentando maximizar el beneficio y reducir al mínimo el riesgo de sangrado. Se incluyeron todos los estudios primarios identificados en los que se comparó un esquema de doble antiagregación, iniciado en el periodo agudo del evento índice (ACV o accidente isquémico transitorio - AIT), contra un esquema de simple antiagregación. El cuerpo de la evidencia mostró que la intervención (doble antiagregación) reduce el riesgo de recurrencia de ACV y probablemente se asocie a un aumento marginal en el riesgo de sangrado mayor. Sugerimos indicar doble esquema antiplaquetario para el tratamiento inicial de pacientes con ACV isquémico menor (Score NIH < o igual a 3 o AIT).

One of the main pillars of acute ischemic stroke management is antiplatelet therapy. Different treatment schemes have been compared, suggesting that the combination of multiple antiplatelet drugs is associated with a reduced risk of stroke recurrence. However, it has also been associated with an increased risk of bleeding complications which, in the long term, surpass the mentioned benefits. However, considering that most stroke recurrences occur i n the short term, a time limited double antiplatelet scheme could result in significant benefits to patients with acute ischemic stroke. On this basis, we conducted a rapid systematic review of the literature in order to evaluate the effects of a short-term double antiplatelet therapy both on stroke recurrence and complications. All trials comparing double versus single antiplatelet therapy in patients with acute ischemic stroke were included. Results showed that double therapy reduces recurrence risk but probably marginally increases major bleeding complications. We suggest double antiplatelet therapy for the initial management of patients with minor (Score NIH < or equal to 3 or transient isquemic attack -TIA) acute ischemic stroke.

Stroke and transient ischemic attacks related to antiplatelet or warfarin interruption / Acidente vascular cerebral e ataques isquêmicos transitórios relacionados à interrupção de antiplaquetários ou varfarina

ABSTRACT Patients on anticoagulant or antiplatelet therapy are often required to discontinue these medications before and during surgical or invasive procedures. In some cases, the patient stops the treatment without medical supervision. These situations may increase stroke risk. Objective To identify the ischemic stroke and transient ischemic attack (TIA) prevalence related to length of time of discontinuation of antiplatelet or vitamin K antagonist therapy, in a group of inpatients from a specialized neurological hospital in Brazil. Methods Cross-sectional, retrospective and descriptive study of stroke inpatients for three years. Medical reports were reviewed to find study participants, stroke characteristics, risk factors, reasons and time of drug interruption. Results In three years, there were 360 stroke and TIA inpatients, of whom 27 (7.5%) had a history of antiplatelet or vitamin K antagonist interruption correlated with the time of the event (81% ischemic stroke, 19% TIA). The median time between antiplatelet interruption and an ischemic event was five days, and 62% of events occurred within seven days after drug suspension. For vitamin K antagonists, the average time to the ischemic event was 10.4 days (SD = 5.7), and in 67% of patients, the time between drug discontinuation and the event was 7-14 days. The most frequent reason for drug suspension was patient negligence (37%), followed by planned surgery or invasive examination (26%) and side effects, including hemorrhage (18.5%). Conclusion Antiplatelet or vitamin K antagonist suspension has a temporal relationship with the occurrence of stroke and TIA. Since these events are preventable, it is crucial that healthcare professionals convince their patients that drug withdrawal can cause serious consequences.

RESUMO Pacientes em terapia anticoagulante ou antiagregante plaquetária frequentemente são solicitados a descontinuar essas medicações antes e durante procedimentos cirúrgicos ou invasivos. Se o paciente interromper tratamento sem supervisão médica, poderá aumentar de risco de acidente vascular cerebral (AVC). Objetivo Identificar prevalência de AVC isquêmico e ataque isquêmico transitório (AIT) associados à descontinuação de terapia antiplaquetária ou coumarínicos em pacientes internados em hospital especializado em atendimento neurológico no Brasil. Métodos Estudo transversal, retrospectivo de três anos, descritivo dos pacientes hospitalizados por AVC. A revisão de relatórios médicos determinou características do AVC, fatores de risco, motivos e tempo de interrupção medicamentosa. Resultados Em três anos, foram internados 360 pacientes por AVC ou AIT; destes, 27 interromperam temporariamente terapia antiplaquetária ou coumarínicos relacionando ao evento (81% acidente vascular cerebral isquêmico, 19% AIT). A prevalência foi de 7,5%. O tempo médio entre interrupção antiplaquetária e evento foi cinco dias, com 62% deles ocorrendo até sete dias após suspensão medicamentosa. Para coumarínicos, o tempo médio foi 10,4 dias (d.p.= 5,7), em 67% dos casos o tempo entre a descontinuação medicamentosa e o evento foi 7-14 dias. O motivo mais frequente para suspensão do medicamento foi negligência do paciente (37%), seguido por cirurgia planejada ou exame invasivo (26%) e efeitos colaterais, incluindo hemorragia (18,5%). Conclusão Suspensão de terapia de antiplaquetários ou coumarínicos tem relação temporal com ocorrência de AVC e de AIT. Esses eventos são passíveis de serem evitados, sendo imprescindível que profissionais de saúde convençam seus pacientes das consequências graves da retirada do medicamento.

Postoperative bleeding following preoperative clopidogrel administration in patients with haemoglobin level above 110 g/l undergoing urgent cabg

Abstract Introduction: Patients with acute coronary syndrome usually receive dual antiplatelet therapy (DAPT) (usually clopidogrel + aspirin) prior to coronary catheterization, and approximately 10% of these patients require coronary artery bypass grafting (CABG). DAPT has favorable effects on prevention of thrombus formation, but it can have deleterious effects on surgical hemostasis. Anaemia, if present, gives additional risk to such patients. The aim of this study was to examine if DAPT affects postoperative bleeding in patients with haemoglobin levels above 110 g/L, who underwent urgent or emergent CABG, less than five days after stopping DAPT therapy. Methods: Data were collected prospectively on 122 CABG patients, operated by a surgical team from March 2008 to August 2013. Patients were stratified into two groups: group 1 received DAPT within 5 days of CABG (n=65), and group 2 where DAPT was discontinued for more than 5 days prior to CABG (n=57). All patients were diagnosed with acute coronary syndrome preoperatively, and all of them had haemoglobin levels above 110 g/L. Patients who needed reoperation, combined procedures, or off-pump revascularization were excluded. Results: There was no hospital mortality. Mean chest tube losses after the surgical revascularization did not differ significantly, but group 1 received a higher quantity of transfused red blood cells and platelets. Conclusion: Urgent and emergent surgical revascularization using extracorporeal circulation in patients with acute coronary syndrome whose preoperative haemoglobin levels are above 110 g/L is a safe and effective procedure. We suggest that, where indicative, one may perform CABG in less than 5 days after the clopidogrel discontinuation.

Manejo perioperatorio de pacientes usuarios de antiagregantes plaquetarios / Perioperative management of patients using antiplatelet agents

Resumen El uso de fármacos antiagregantes plaquetarios para prevención primaria y secundaria de eventos cardiovasculares es una práctica común en clínica. La terapia antiagregante plaquetaria disminuye significativamente la incidencia de eventos cardiovasculares, incluyendo infarto agudo al miocardio y accidente cerebro-vascular. Cada vez es más frecuente enfrentarse a pacientes en terapia antiagregante plaquetaria que serán sometidos a algún procedimiento quirúrgico, por tanto es fundamental conocer el manejo perioperatorio de estos fármacos, para disminuir los riesgos y complicaciones asociados a la suspensión o mantención de estas drogas en el período perioperatorio. Los antiagregantes plaquetarios de mayor uso en Chile son la aspirina y las tienopiridinas, siendo el clopidogrel el fármaco más utilizado en este grupo. El enfrentamiento perioperatorio de estos fármacos está supeditado al riesgo trombótico individual de cada paciente y al riesgo hemorrágico de cada cirugía. En cirugías no cardiacas, se sugiere mantener la aspirina, excepto en pacientes con bajo-moderado riesgo trombótico que serán sometidos a cirugías con alto riesgo de sangrado, en los cuales se recomienda suspenderla 5-7 días previo a la intervención quirúrgica. El clopidogrel se sugiere suspenderlo 5 días antes de la cirugía, excepto en pacientes con alto riesgo trombótico que se someterán a procedimientos quirúrgicos con riesgo hemorrágico bajo-moderado. En cirugías de revascularización miocárdica, se recomienda mantener aspirina y suspender clopidogrel 5 días antes del procedimiento. En relación al reinicio postquirúrgico de estos fármacos, se sugiere reanudar aspirina 6 h posterior a la cirugía y clopidogrel durante las primeras 24 h postoperatorias, asegurando previamente una adecuada hemostasia quirúrgica.

The use of antiplatelet drugs for primary and secondary prevention of cardiovascular disease events is a common clinical practice. Antiplatelet therapy significantly decreases the incidence of cardiovascular disease events, including acute myocardial infarction and cerebrovascular accident. It is increasingly common to face patients on antiplatelet therapy who will undergo some surgical procedure, so it is essential to know the perioperative management of these drugs, to reduce the risks and complications associated with the suspension or maintenance of these therapies in the perioperative period. The most common antiplatelet agents used in Chile are acetylsalicylic acid and thienopyridines, of which clopidogrel is the most frequent one. The perioperative management of these drugs has to be based on the individual thrombotic risk of each patient and the risk of hemorrhage of each surgery. In noncardiac surgeries, it is suggested to maintain acetylsalicylic acid, except in patients with low to moderate thrombotic risk who will undergo surgeries with a high risk of bleeding, in which case it is recommended to suspend it 5 to 7 days before surgery. Clopidogrel is suggested to be discontinued 5 days before surgery, except in patients with high thrombotic risk who will undergo surgical procedures with low to moderate risk of hemorrhage. In myocardial revascularization surgeries, it is recommended to maintain acetylsalicylic acid and to suspend clopidogrel 5 days before the procedure. Once assuring adequate surgical hemostasis, it is suggested to reinitiate acetylsalicylic acid 6 hours after surgery and to reinitiate clopidogrel during the first 24 postoperative hours.

Effect of clopidogrel with or without omeprazole in patients with carotid artery stenting / Efecto del clopidogrel con o sin omeprazol en pacientes con stent en la arteria carótida

BACKGROUND: Recent concerns have been raised about the potential for proton pump inhibitors (PPIs) to blunt the efficacy of clopidogrel. We observed the effect of clopidogrel plus aspirin with or without omeprazole in patients with carotid stenoses after they received placement of carotid stents. METHODS: Sixty-four consecutive patients treated with percutaneous carotid artery stenting (CAS) comprised the sample. All enrolled patients underwent the C13 urea breath test (C13 UBT) before CAS. Patients with Helicobacter pylori infection and a history of peptic ulcer were assigned dual antiplatelet combination with omeprazole. Others received dual antiplatelet without omeprazole. Transcranial Doppler and ultrasonography were performed to assess the middle cerebral artery and carotid artery in follow-up at three months and six months. RESULTS: Eight patients had gastrointestinal bleeding; the event rate was 22.6% without omeprazole and 3.8% with omeprazole. The rate of gastrointestinal bleeding was reduced with omeprazole as compared without omeprazole (p = 0.026, p < 0.05). The two groups did not differ significantly in the rate of instent restenosis and thrombus through transcranial Doppler and ultrasonography. CONCLUSION: Among patients receiving dual antiplatelet therapy, prophylactic use of omeprazole reduced the rate of upper gastrointestinal bleeding. There was no apparent interaction between clopidogrel and omeprazole in patients with carotid artery stenting.

ANTECEDENTES: Recientemente se han expresado preocupaciones acerca de la posibilidad de que los inhibidores de la bomba de protones (IBP) para debilitar la eficacia del clopidogrel. Observamos el efecto del clopidogrel más aspirina con o sin omeprazol en pacientes con estenosis de la arteria carótida después de que recibieran la colocación de stents carotídeos. MÉTODOS: Sesenta y cuatro pacientes consecutivos tratados con stent percutáneo de la arteria carótida (SAC) fueron seleccionados para formar la muestra. A todos los pacientes inscritos se les realizó la prueba de aliento con urea C13 (C13 UBT) antes de CAS. A pacientes con infección por Helicobacter pylori y antecedentes de úlcera péptica les fue asignada una combinación antiplaquetaria dual con omeprazol. Otros recibieron tratamiento antiplaquetario dual sin omeprazol. Se realizaron una prueba Transcranial Doppler y una ultrasonografía a fin de evaluar la arteria cerebral media y la arteria carótida en seguimientos a los tres meses y a los seis meses. RESULTADOS: Ocho pacientes tuvieron hemorragia gastrointerstinal; la tasa de eventos fue 22.6% sin omeprazol y 3.8% con omeprazol. La tasa de hemorragia gastrointerstinal se redujo con omeprazol en comparación con la obtenida sin omeprazol (p = 0,026, p < 0.05). Los dos grupos no difirieron significativamente con respecto a la tasa de restenosis en stent y trombos a través de la prueba Transcranial Doppler y la ultrasonografía. CONCLUSIÓN: Entre los pacientes que reciben terapia antiplaquetaria dual, el uso profiláctico de omeprazol redujo la tasa de hemorragia gastrointestinal superior. No hubo interacción ostensible entre el clopidogrel y el omeprazol en pacientes con stent de la arteria carótida.