The rs4783961 and rs708272 genetic variants of the CETP gene are associated with coronary artery disease, but not with restenosis after coronary stenting / Los polimorfismos rs4783961 y rs708272 del gen CETP son asociados con la enfermedad arterial coronaria y no con la restenosis tras el implante de un stent coronario

Abstract Objective: We evaluated whether cholesteryl ester transfer protein (CETP) gene polymorphisms are associated with the presence of coronary artery disease (CAD) and/or restenosis in patients with coronary stent. Methods: Two polymorphisms of the CETP gene [−971 A/G (rs4783961), and Taq1B A/G (rs708272)] were genotyped by 5'exonuclease TaqMan assays in 219 patients with CAD (66 patients with restenosis and 153 without restenosis) and 607 control individuals. Results: The distribution of polymorphisms was similar in patients with and without restenosis. However, when the whole group of patients (with and without restenosis) was compared to healthy controls, under dominant model, the G allele of the Taq1B A/G polymorphism was associated with increased risk of CAD (odds ratio [OR] = 1.48, pCDom = 0.032). In the same way, under codominant, dominant, and additive models, the A allele of the −971 A/G polymorphisms was associated with an increased risk of developing CAD (OR = 2.03, pCCo-dom = 0.022, OR = 1.83, pCDom = 0.008, and OR = 1.39, pCAdd = 0.011, respectively). In addition, the linkage disequilibrium showed that the "AG" haplotype was associated with increased risk of developing CAD (OR = 1.28, p = 0.03). Conclusion: This study demonstrates that CETP Taq1B A/G and CETP −971 A/G polymorphisms are associated with an increased risk of developing CAD, but no association with restenosis was observed.

Resumen Objetivo: Evaluamos si los polimorfismos del gen CETP están asociados con la presencia de enfermedad arterial coronaria (EAC) y/o restenosis en pacientes con stent coronario. Métodos: En este estudio se genotiparon dos polimorfismos del gen CETP [−971 A/G (rs4783961) y Taq1B A/G (rs708272)] mediante ensayos de 5'exonucleasa TaqMan en 219 pacientes con EAC (66 pacientes con restenosis y 153 sin restenosis), y 607 individuos de control. Resultados: La distribución de polimorfismos fue similar en pacientes con y sin restenosis. Sin embargo, cuando se comparó todo el grupo de pacientes (con y sin restenosis) con controles sanos, bajo el modelo dominante el alelo G del polimorfismo Taq1B A/G se asocia con un mayor riesgo de EAC (OR = 1.48, pCDom = 0.032). De la misma manera, bajo los modelos co-dominante, dominante y aditivo, el alelo A de los polimorfismos −971 A/G se asocia con un mayor riesgo de desarrollar EAC (OR = 2.03, pCCo-dom = 0.022, OR = 1.83, pCDom = 0,008 y OR = 1.39, pCAdd = 0.011, respectivamente). Adicionalmente, el desequilibrio de ligamiento mostró que el haplotipo "AG" se asocia con un mayor riesgo de desarrollar EAC (OR = 1.28, p = 0.03). Conclusión: En resumen, este estudio demuestra que los polimorfismos CETP Taq1B A/G y CETP −971 A/G están asociados con un mayor riesgo de desarrollar CAD, pero no se observó asociación con restenosis.

Síndrome metabólico, lipoproteína(a) y aterosclerosis subclínica en población mexicana / Metabolic syndrome, lipoprotein(a) and subclinical atherosclerosis in Mexican population

Resumen Objetivo: Investigar la asociación del síndrome metabólico y la lipoproteína(a) [Lp(a)] con el riesgo de aterosclerosis subclínica en adultos mexicanos. Método: En 953 mujeres y hombres se evaluaron datos clínicos, bioquímicos y tomográficos de grasa abdominal visceral, subcutánea, hepática y calcio arterial coronario. La Lp(a) se determinó mediante nefelometría y el síndrome metabólico se diagnosticó con los criterios del Adult Treatment Panel III. La asociación independiente de estas variables con el calcio arterial coronario se obtuvo con análisis de regresión logística multivariada. Resultados: La edad, el peso, el índice de masa corporal, la presión arterial sistólica y diastólica, los volúmenes de grasa abdominal, los lípidos, la glucosa, la insulina y el índice de resistencia a insulina fueron significativamente mayores en los sujetos con síndrome metabólico, mientras que la mediana de Lp(a) fue más baja en comparación con los sujetos sin el síndrome (3.7 [rango intercuartílico (RIC): 2.3-9.2 vs. 5.9 [RIC: 2.5-13.1) mg/dl; p < 0.01). El número de componentes y el síndrome metabólico se asociaron inversamente con la Lp(a) elevada (> 30 mg/dl). La presencia de síndrome metabólico se asoció con un riesgo de calcio arterial coronario > 0 (odds ratio [OR]: 2.19; intervalo de confianza del 95% [IC95%]: 1.64-2.94; p < 0.001), independientemente de la Lp(a) elevada. La glucemia > 100 mg/dl (OR: 2.42; IC95%: 1.7-3.4; p < 0.0001) y la presión arterial elevada (OR: 2.14; IC95%: 1.5-3.1; p > 0.0001) se asociaron con calcio arterial coronario > 0. Conclusiones: En población mexicana existe una asociación inversa entre la concentración de Lp(a) y el síndrome metabólico. Este y sus componentes se asociaron positivamente con aterosclerosis subclínica. La elevada prevalencia de obesidad, diabetes, hipertensión arterial, triglicéridos elevados y concentración de colesterol unido a lipoproteínas de alta densidad que caracterizan a la población mexicana pudieran explicar las diferencias con otras poblaciones.

Abstract Objective: To assess the relationship of metabolic syndrome (MetS) and Lp(a) with subclinical atherosclerosis (CAC) in Mexican adults. Method: Clinical, biochemical and tomographic data of visceral, subcutaneous, hepatic abdominal fat and CAC were evaluated in 953 women and men. Lp(a) was determined by nephelometry and MetS was diagnosed according to ATP III criteria. Multivariate logistic regression analysis was performed to determine the independent association of these variables with CAC. Results: Age, weight, body mass index, systolic and diastolic blood pressure, volumes of visceral, subcutaneous and hepatic abdominal fat, lipids, glucose, insulin and HOMA-RI were significantly higher in subjects with MetS. The median Lp(a) was lower in subjects with MetS compared to subjects without MetS (3.7 [IR: 2.3-9.2 vs. 5.9 [IR: 2.5-13.1) mg/dL; p < 0.01). The number of components and the MetS were inversely associated with the elevated Lp(a) (> 30 mg / dL). The presence of MetS was associated with a CAC risk >0 (OR: 2.19, [95% CI (1.64-2.94)]; p < 0.001), independently of elevated Lp(a). The components of MetS that were independently associated with the presence of CAC > 0 UA were glycaemia > 100 mg/dL (OR 2.42, [95% CI (1.7-3.4)]; p < 0.0001) and high blood pressure (OR 2.14 [95% CI (1.5-3.1)]; p < 0.0001). Conclusions: In Mexican population there is an inverse association between Lp(a) levels and MetS. The MetS and its components were associated with subclinical atherosclerosis. The high prevalence of obesity, diabetes, high blood pressure high triglycerides and low HDL-C, characteristics of Mexican population could explain the differences with other populations.

Coronary artery calcium is associated with lpa gene variant RS7765803-C in Mexican mestizo population The GEA Project

ABSTRACT Background: Lipoprotein(a) [Lp(a)] levels are genetically determined; high levels are a risk factor for coronary disease, although their association with coronary artery calcium (CAC) is controversial. Objective: The objective of the study was to assess the association of LPA gene polymorphisms with CAC in a Mexican Mestizo population. Methods: We included 1594 subjects 35-70 years old. Six polymorphisms of the LPA gene were analyzed. CAC score was determined by tomography and Lp(a) serum levels by immunonephelometry. The association of LPA polymorphism with CAC and Lp(a) was evaluated by logistic regression. Results: The prevalence of Lp(a) ≥30 mg/dL was 10%, and of CAC >0 was 26.9%. Three polymorphisms were associated with high Lp(a) levels: rs10455872-G (p = 0.013), rs6907156-T (p = 0.021), and rs7765803-C (p = 0.001). Homozygotes (CC) for the rs7765803 variant compared with the G allele (CG + GG) carriers had higher Lp(a) levels (8.9 [3.3-23.9] vs. 4.9 [2.3-11.2] mg/dL; p = 0.015) and higher prevalence of CAC >0 (36.5% vs. 26.3%, p = 0.045) and were associated with CAC > 0 (odds ratio = 1.7, 95% confidence interval: 1.06-2.7; p < 0.026). The other polymorphisms were not associated with CAC. Conclusions: This is the first study to demonstrate in a Mexican Mestizo population that carriers of the rs7765803-C allele of LPA gene have 2.6 times greater risk for high Lp(a) values and 1.7 times higher risk for coronary artery disease.

The branched-chain amino acid transaminase 1 -23c/g polymorphism confers protection against acute coronary syndrome

ABSTRACT Background: Previous studies have shown an association between polymorphisms of the BAT1-NF-κB inhibitor-like-1 (NFKBIL1)-LTA genomic region and susceptibility to myocardial infarction and acute coronary syndrome (ACS). Objective: The objective of the study was to study the role of three polymorphisms in the BAT1, NFKBIL1, and LTA genes on the susceptibility or protection against ACS; we included a group of cases-controls from Central Mexico. Methods: The BAT1 rs2239527C/G, NFKBIL1 rs2071592T/A, and LTA rs1800683G/A polymorphisms were genotyped using a 5' TaqMan assay in a group of 625 patients with ACS and 617 healthy controls. Results: Under a recessive model, the BAT1 -23C/G (rs2239527) polymorphism showed an association with protection against ACS (odds ratio = 0.56, and p-corrected = 0.019). In contrast, the genotype and allele frequencies of the NFKBIL1 rs2071592T/A and LTA rs1800683G/A polymorphisms were similar between ACS patients and controls and no association was identified. Conclusion: Our data suggest an association between the BAT1 -23C/G polymorphism and protection against ACS in Mexican patients.

Polymorphisms in ß-adrenergic receptors are associated with increased risk to have a positive head-up tilt table test in patients with vasovagal syncope

Abstract Background Vasovagal syncope (VVS) is a frequent clinical condition in which a genetic background seems to be implicated. Considering that the adrenergic receptors (ARs) may play a role in VVS, the present study has as principal aim to determine if the α- and β-AR (ADRA and ADRB) gene polymorphisms are associated with an increased risk to have a positive head-up tilt table (HUTT) test in patients with VVS. Methods: Nine polymorphisms in the ADRA1A (rs1048101, rs1383914, rs574584, and rs573542), ADRB1 (rs1801252 and rs1801253), ADRB2 (rs1042713 and rs1042714), and ADRB3 (rs4994) genes were analyzed using the 5’ exonuclease TaqMan genotyping assay in a group of 134 patients with VVS. Results Under different models, the rs1801252 (OR = 8.63, 95% CI: 0.95-78.72, Precessive = 0.02), rs1042713 (OR = 1.94, 95% CI: 1.02-3.66, Padditive = 0.04), and rs4994 (OR = 2.46, 95% CI: 1.01-6.01, Pdominant = 0.042 and OR = 2.62, 95% CI: 1.04-6.63, Pover-dominant = 0.03) polymorphisms were associated with increased risk for a positive HUTT. All models were adjusted for statistically significant covariates. Conclusion These results suggest that some polymorphisms of the β-AR genes could contribute to a positive tilt test in patients with VVS.

Prevalencia y extensión de la calcificación arterial coronaria en población mexicana asintomática cardiovascular: estudio Genética de la Enfermedad Aterosclerosa / Prevalence and extent of coronary artery calcification in an asymptomatic cardiovascular Mexican population: Genetics of Atherosclerotic Disease study

Resumen: Objetivo: La prevalencia de calcificación arterial coronaria (CAC), marcador específico de aterosclerosis, no es conocida en México. Nuestro objetivo fue investigar la prevalencia y extensión de CAC y su asociación con factores de riesgo cardiovascular en población mexicana. Métodos: La CAC fue medida por tomografía computarizada multidetector en individuos asintomáticos que participaron en el estudio Genética de la Enfermedad Aterosclerosa. Los factores de riesgo cardiovascular y los medicamentos fueron registrados. Resultados: La muestra incluyó 1,423 individuos (49.5% hombres), con una edad de 53.7 ± 8.4 años. Los portadores de CAC mostraron prevalencias más altas de dislipidemia, diabetes, hipertensión y otros factores de riesgo. La prevalencia de CAC > 0 unidades Agatston fue de 27%, significativamente más alta en hombres (40%) que en mujeres (13%). Los valores medios del puntaje de CAC aumentaron consistentemente con la edad y fueron más altos en hombres que en mujeres en todos los grupos etarios. La edad y el c-LDL elevado se asociaron de manera independiente con la prevalencia de CAC > 0 en hombres y mujeres, mientras que la presión arterial sistólica en las mujeres, y el incremento de la edad en ambos géneros mostró una asociación independiente con la severidad de CAC. Conclusiones: En población mexicana la prevalencia y la extensión de CAC fueron mucho más altas en hombres que en mujeres y aumentaron consistentemente con la edad. Los predictores independientes de la prevalencia de CAC fueron la edad y el c-LDL.

Abstract: Objective: The prevalence of coronary artery calcification (CAC), a specific marker of atherosclerosis, is unknown in Mexico. Our aim was to investigate the prevalence and quantity of CAC and their association with cardiovascular risk factors in a Mexican population. Methods: CAC was measured by multidetector computed tomography in asymptomatic subjects who participated in the Genetics of Atherosclerotic Disease study. Cardiovascular risk factors and medication were recorded. Results: The sample included 1,423 individuals (49.5% men), aged 53.7 ± 8.4 years. Those with CAC showed a higher prevalence of dyslipidaemia, diabetes, hypertension, and other risk factors. The prevalence of CAC > 0 Agatston units was significantly higher among men (40%) than among women (13%). Mean values of CAC score increased consistently with increasing age and were higher in men than women in each age group. Age and high low density lipoprotein cholesterol were independently associated with prevalence of CAC > 0 in men and women, while increasing systolic blood pressure in women and age in both genders showed an independent association with CAC extension. Conclusions: In the Mexican population the prevalence and extent of CAC were much higher in men than in women, and strongly increased with age. Independent predictors of CAC prevalence were age and low density lipoprotein cholesterol (LDL-C).

Prevalencia y asociación de la calcificación valvular aórtica con factores de riesgo y aterosclerosis coronaria en población mexicana / Aortic valve calcification prevalence and association with coronary risk factors and atherosclerosis in Mexican population

Resumen: Objetivo: La prevalencia de calcificación valvular aórtica (CVA) tiene influencia importante de la etnia y se desconoce en población mexicana. Nuestro objetivo fue investigar la prevalencia de CVA y sus asociaciones con factores de riesgo cardiovascular y calcificación arterial coronaria (CAC). Método: En 1,267 sujetos (53% mujeres) sin enfermedad coronaria conocida y con edad de 35 a 75 años, la CVA y la CAC se evaluaron mediante tomografía computada multidetector, utilizando el método de Agatston. Los factores de riesgo cardiovascular se documentaron en todos los participantes. Las asociaciones de CVA con CAC y factores de riesgo se estimaron usando el análisis de regresión logística múltiple. Resultados: La prevalencia global de CVA y CAC fue del 19.89% y del 26.5%, respectivamente. Ambas condiciones aumentaron con la edad y se encontraron con mayor frecuencia en hombres (25.5 y 37.1%, respectivamente) que en mujeres (14.9 y 13%, respectivamente). La CVA se observó en únicamente el 8.5% de los sujetos sin CAC, mientras que en aquellos con CAC 1-99, 100-399 y > 400 unidades Agatston, las prevalencias fueron del 36.8, 56.8 y 84%, respectivamente. El análisis de regresión logística múltiple ajustado por edad, género, obesidad, inactividad física, hipertensión, dislipidemia y valores altos de insulina, mostró que la presencia de CAC (RM [IC95%]: 3.23 [2.26-4.60]), obesidad (1.94 [1.35-2.79]), género masculino (1.44 [1.01-2.05]) y edad (1.08 [1.03-1.10]), fueron predictores independientes y significativos de la CVA. Conclusiones: La prevalencia de CVA es alta y se asocia significativamente con factores de riesgo aterosclerótico y CAC en población mexicana.

Abstract: Objetive: The prevalence of aortic valve calcification (AVC), strongly influenced by ethnicity, is unknown in Mexican population. The aim of this study was to investigate the prevalence of AVC and its associations with cardiovascular risk factors and coronary artery calcification (CAC), in Mexican subjects. Methods: In 1,267 subjects (53% women) without known coronary heart disease, aged 35 to 75 years, AVC and CAC were assessed by multidetector-computed tomography using the Agatston score. Cardiovascular risk factors were documented in all participants. The associations of AVC with CAC and risk factors were assessed by multivariable logistic regression analyses. Results: The overall prevalence of AVC and CAC was 19.89% and 26.5%, respectively. AVC and CAC increased with age and were found more frequently in men (25.5% and 37.1%, respectively) than in women (14.9% and 13.0%, respectively). AVC was observed in only 8.5% of subjects wit-hout CAC, while those with CAC 1-99, 100-399, and > 400 Agatston units had AVC prevalences of 36.8%, 56.8%, and 84.0%, respectively. The multivariable logistic regression analyses, adjusted for age, gender, obesity, physical inactivity, hypertension, dyslipidemia and high insulin levels, showed that the presence of CAC (OR [CI95%]: 3.23 [2.26-4.60]), obesity (1.94 [1.35-2.79]), male gender (1.44 [1.01-2.05]) and age (1.08 [1.03-1.10]), were significant independent predictors of AVC. Conclusion: Prevalence of AVC is high and significantly associated with atherosclerotic risk factors and CAC in this Mexican population.

Next generation sequencing for molecular confirmation of hereditary sudden cardiac death syndromes / Confirmación diagnóstica molecular mediante secuenciación masiva de nueva generación ("next generation sequencing") en síndromes hereditarios de muerte súbita cardíaca

Hereditary sudden cardiac death syndromes comprise a wide range of diseases resulting from alteration in cardiac ion channels. Genes involved in these syndromes represent diverse mutations that cause the altered encoding of the diverse proteins constituting these channels, thus affecting directly the currents of the corresponding ions. In the present article we will briefly review how to arrive to a clinical diagnosis and we will present the results of molecular genetic studies made in Mexican subjects attending the SCD Syndromes Clinic of the National Institute of Cardiology of Mexico City.

Los síndromes hereditarios de muerte súbita cardíaca comprenden una amplia gama de enfermedades resultantes de la alteración en los canales iónicos cardíacos. Los genes implicados en estos síndromes presentan mutaciones que causan alteraciones de las diversas proteínas que constituyen estos canales y que, por lo tanto, afectan directamente a las diferentes corrientes iónicas. En el presente artículo se revisa brevemente la forma de llegar a un diagnóstico clínico de dichos síndromes y se presentan los resultados de los estudios genéticos moleculares realizados en sujetos mexicanos que asisten a la Clínica de Síndromes Hereditarios de Muerte Súbita del Instituto Nacional de Cardiología Ignacio Chávez.

Síndrome de Andersen-Tawil: una revisión del diagnóstico genético y clínico con énfasis en sus manifestaciones cardíacas / Andersen-Tawil syndrome: A review of its clinical and genetic diagnosis with emphasis on cardiac manifestations

El síndrome de Andersen-Tawil resulta de la alteración de canales de potasio, se hereda de forma autosómica dominante y se cataloga como el tipo 7 de los síndromes de QT largo congénitos. El gen afectado es el KCNJ2, el cual codifica la proteína Kir2.1 que forma el canal de potasio rectificador interno («inward rectifier¼). Este canal interviene en la estabilización del potencial de membrana en reposo y controla la duración del potencial de acción en el sistema musculoesquelético y cardíaco. En miocitos ventriculares, es un componente responsable de la rectificación de la corriente de potasio en la fase 3 del potencial de acción. Debido a que Kir2.1 está presente en el sistema musculoesquelético, corazón y cerebro, las alteraciones de esta proteína dan origen a las principales características del síndrome: parálisis flácida, arritmias ventriculares y alteraciones leves a moderadas en el desarrollo del esqueleto, especialmente en manos y pies. En la presente revisión se aborda esta enfermedad desde el punto de vista del diagnóstico clínico y molecular con énfasis en sus manifestaciones cardíacas.

The Andersen-Tawil syndrome is a cardiac ion channel disease that is inherited in an autosomal dominant way and is classified as type 7 of the congenital long QT syndromes. Affected gene is KCNJ2, which forms the inward rectifier potassium channel designated Kir2.1. This protein is involved in stabilizing the resting membrane potential and controls the duration of the action potential in skeletal muscle and heart. It also participates in the terminal repolarization phase of the action potential in ventricular myocytes and is a major component responsible for the correction in the potassium current during phase 3 of the action potential repolarization. Kir 2.1 channel has a predominant role in skeletal muscle, heart and brain. Alterations in this channel produce flaccid paralysis, arrhythmias, impaired skeletal development primarily in extremities and facial area. In this review we address the disease from the point of view of clinical and molecular diagnosis with emphasis on cardiac manifestations.

Toll-like receptor 4 gene polymorphisms and acute coronary syndrome: No association in a Mexican population / No existe asociación entre los polimorfismos del receptor tipo toll-4 y el síndrome coronario agudo

Objective: The objective of this study was to establish the role of the TLR-4 gene polymorphisms in individuals in risk of developing ACS. Methods: The study included 457 Mexican patients with ACS and 283 control individuals. The TLR-4 Asp299Gly and TLR-4 Thr399Ile single nucleotide polymorphisms were genotyped using 5' exonuclease TaqMan genotyping assays on an 7900HT Fast real-time PCR system according to manufacturer's instructions (Applied Biosystems, Foster City, USA). Results: The results obtained in this study showed that the frequency of the two polymorphisms (TLR-4 Asp299Gly and TLR-4 Thr399Ile) studied were similar between patients with ACS and healthy controls. Multiple logistic regression analysis showed that the largest risk factor for ACS development was given by smoking (11.88-fold increased risk), hypertension (4.32-fold increased risk), type II diabetes (3.44-fold increased risk), gender (2.32-fold increased risk), and dyslipidemia (1.52-fold increased risk). Conclusion: The Asp299Gly and Thr399Ile polymorphisms were not associated with susceptibility to ACS in the Mexican population.

Objetivo: El objetivo de este estudio fue establecer el papel de los polimorfismos del gen TLR-4 en individuos en riesgo de desarrollar síndrome coronario agudo (SCA). Métodos: El estudio incluyó a 457 pacientes mexicanos con SCA y 283 individuos como grupo control. Los polimorfismos de un solo nucleótido TLR-4 Asp299Gly y TLR-4 Thr399Ile fueron determinados usando ensayos TaqMan 5' exonucleasa en un equipo tiempo real 7900HT (Fast real-time PCR system) de acuerdo con instrucciones del fabricante Applied Biosystems, Foster City, EE.UU. Resultados: Los resultados obtenidos mostraron que las frecuencias de los 2 polimorfismos (TLR-4Asp299Gly y TLR-4 Thr399Ile) estudiados fueron similares entre pacientes con SCA e individuos control. No obstante, el análisis de regresión logística mostró que los factores de mayor riesgo para desarrollar SCA se debieron a tabaquismo (incrementa 11.88 veces el riesgo), hipertensión (incrementa 4.32 veces el riesgo), diabetes tipo 2 (incrementa 3.44 veces el riesgo), género (incrementa 2.32 veces el riesgo), y la dislipidemia (incrementa 1.52 veces el riesgo). Conclusión: Determinamos que los polimorfismos Asp299Gly y Thr399Ile no se asocian con la susceptibilidad al SCA en la población mexicana.

The MHC2TA gene polymorphisms are not associated with restenosis after coronary stenting in Mexican patients / Los polimorfismos del gen MHC2TA no se asocian con la reestenosis después del implante de stent coronario en pacientes mexicanos

Objective: The aim of this study was to test for association between MHC2TA gene polymorphisms and risk for restenosis after coronary stent placement in a group of Mexican patients. Methods: The MHC2TA-168A>G (rs3087456), 1614C>G (rs4774), and 2536G>A (rs2229320) single nucleotide polymorphisms were genotyped using 5' exonuclease TaqMan genotyping assays in a group of 202 patients, who underwent coronary artery stenting. Basal and procedure coronary angiography were analyzed, looking for angiographic predictors of restenosis and follow-up angiography was performed to screen for binary restenosis. Results: The results obtained in this study showed that the frequency of the three polymorphisms studied was similar in patients with and without restenosis. Univariate analysis showed that the use of drug-eluting stent (DES) reduces the risk of developing restenosis (p < 0.001, OR = 0.26). In contrast, the diameter< 2.5 mm of the stent and bifurcations increased the risk of developing restenosis (p = 0.049, OR = 1.74 and p = 0.041, OR = 1.8). Conclusion: The present study suggests that the MHC2TA polymorphisms are not involved in the risk of developing restenosis after coronary stent placement.

Objetivo: El propósito de este estudio fue evaluar la asociación de los polimorfismos del gen MHC2TA y el riesgo de desarrollar reestenosis, después del implante de stent coronario en un grupo de pacientes mexicanos. Métodos: Los polimorfismos de un solo nucleótido MHC2TA-168A>G (rs3087456), 1614C>G (rs4774) y 2536G>A (rs2229320), se determinaron en un grupo de 202 pacientes tratados con stent coronario. Los polimorfismos fueron evaluados utilizando ensayos de genotipificacion Taq-Man 5' exonucleasa. El procedimiento basal y la búsqueda de predictores de reestenosis fueron analizados por medio de angiografía coronaria, y seguimiento angiográfico con el fin de detectar reestenosis binaria. Resultados: Los resultados obtenidos en este estudio mostraron que la distribución génica de los tres polimorfismos estudiados fue muy similar, en pacientes con o sin reestenosis. Sin embargo, el análisis univariado mostró que el uso de los stent medicados reducen el riesgo de desarrollar reestenosis (p < 0.001, OR = 0.26). En contraste, con las bifurcaciones y el diámetro < 2.5 mm del stent que se incrementa el riesgo de desarrollar reestenosis (p = 0.049, OR = 1.74 y p = 0.041, OR = 1.8). Conclusión: El presente estudio sugiere que los polimorfismos del gen MHC2TA no están asociados con el riesgo de desarrollar reestenosis, después del implante de stent coronario.

Genética y genómica de la hipertensión arterial: una actualización / Genetic and genomic studies in the hypertension: an actualization

La hipertensión arterial es considerada la principal causa de riesgo para el desarrollo de infarto agudo al miocardio, falla cardiaca, arritmia ventricular, nefropatía, ceguera, entre otras. La hipertensión arterial es una enfermedad multifactorial en la que participan factores ambientales, genéticos e intrínsecos como raza y género. La Organización Mundial de la Salud ha estimado que la prevalencia de la hipertensión se incrementará drásticamente, de modo que en la próxima década será la primera causa de muerte a nivel mundial, debido al elevado número de muertes (17.5 millones) por enfermedades cardiovasculares registradas a nivel mundial. No obstante, los datos publicados en la Encuesta Nacional de la Secretaría de Salud en 2006, señalan aproximadamente 17 millones de hipertensos en población adulta y una prevalencia de 30.8%, cifra que indica que la hipertensión arterial aumentó su morbilidad del año 2000 al 2005. Sin embargo, poco se ha logrado en la comprensión de los mecanismos moleculares y genéticos involucrados en el desarrollo de esta patología y en consecuencia su prevalencia sigue aumentando drásticamente. Con el uso de las nuevas tecnologías para el análisis de las variantes en el genoma, se han identificado algunos genes en diferentes loci que confieren susceptibilidad al desarrollo de hipertensión arterial. La finalidad de esta revisión es hacer una comparación entre los diferentes estudios en genética y genómica relacionados con esta patología a nivel mundial y en nuestro país, con la finalidad de identificar genes clave que participen en la susceptibilidad al desarrollo de la hipertensión arterial.

The arterial hypertension is considered to be the main risk factor for myocardial infarction, heart failure, ventricular arrhythmias, kidney failure, blindness and other diseases. Arterial hypertension is a multifactorial disease derived from environmental, genetic, gender and ethnic factors. In recent years, the World Health Organization estimated that approximately 17.5 million of deaths were due to cardiovascular diseases worldwide and that this pathology will become the leading cause of death in the next decade. Data from the National Survey of Mexican Ministry of Health (2006), reported approximately 17 million hypertensive adults, equivalent to a prevalence of 30.8% among Mexican population. As a consequence, hypertension represents the leading cause of morbidity from 2000 to 2005 and is increasing in recent years. However, studies have failed to clearly identify the molecular and genetic mechanisms of this pathology so far. Nevertheless, using the new technologies for analysis of variants in the genome, several genes in different loci that confer susceptibility to develop hypertension have been identified. In this review we compared the different studies in genetics and genomics of the hypertension that have been made worldwide and in Mexico, with the aim of identifying important genes involved in susceptibility to the development of this pathology.

Marcadores pro y antiinflamatorios en la enfermedad arterial coronaria y el síndrome isquémico coronario agudo / Pro-inflammatory and anti-inflammatory markers in coronary artery disease and acute ischemic coronary syndrome

Inflammation plays an important role in the development of atherosclerotic lesions, affecting several stages of the atheroma's development going from the initial leukocyte recruitment to the eventual rupture of the unstable atherosclerotic plaque. The inflammatory reactions within coronary atherosclerotic plaques influence the clinical outcome of acute coronary syndromes and coronary artery disease. Recent studies suggest that inflammation markers may reflect different aspects of the atherothrombotic process in relation to the stages of acute coronary syndrome. These markers play an important role in the risk of developing coronary artery disease, and may correlate with its severity. Some cytokines, acute phase proteins, acute phase reactants proteins, and adhesion molecules released from the inflammatory cells may reflect the inflammatory process in atherosclerotic plaques. However, it remains to be determined whether these pro- and anti-inflammation markers may confer risk or protection for cardiovascular disease, or simply reflect the underlying disease process. The analysis of the markers may be useful for the development of new strategies for coronary disease prevention and treatment. Therefore, we need a well-designed evaluation of these markers before their use in the clinical practice.

Actividades paraoxonasa y arilesterasa bajas en sujetos mexicanos con enfermedad arterial coronaria / Low paraoxonase and arylesterase plasma activities in mexican patients with coronary artery disease

PURPOSE: To determine the Paraoxonase-1 (PON1) activity as well as its pheno- and genotypes at position 192 in Mexican subjects with diagnosis of coronary heart disease (CHD). METHODS: We determined the PON1-192 polymorphism by PCR-RFLP, and serum PON1 activity, using either paraoxon (PONase activity) or phenylacetate (ARE activity) as substrates, in 155 clinically healthy individuals (control group), and 155 patients with at least one myocardial infarction (CHD group). The biochemical A/B phenotype was determined by the ratio of the NaCI 1 M-stimulated PONase activity divided by the ARE activity. RESULTS: We found significantly lower PONase and ARE activities in CHD patients as compared to controls (233.1 +/- 102.1 vs. 295.8 +/- 159.1 nmol/min/mL, and 103.1 +/- 33.7 vs 220.2 +/- 120.7 micromol/min/mL, respectively, p<0.05 for both). Allele and genotype frequencies for PON1-192 were similar in CHD patients and healthy controls. Moreover, in the control group, the PON1-192 Q/R genotype did not matched with the A/B phenotype as has been proposed by other studies. CONCLUSIONS: There were important differences in the ARE and PONase activities between Mexican CHD patients and controls, suggesting that PON1 activity could be a good marker of CHD risk, whereas PON1-192 lacks of value to assess such risk.

Guías clínicas para la detección, prevención, diagnóstico y tratamiento de hipertensión arterial sistémica en México (2008) / Clinical guidelines for detection, prevention, diagnosis and treatment of systemic arterial hypertension in Mexico (2008)

The multidisciplinary Institutional Committee of experts in Systemic Arterial Hypertension from the National Institute of Cardiology [quot ]Ignacio Chávez[quot ] presents its update (2008) of [quot ]Guidelines and Recommendations[quot ] for the early detection, control, treatment and prevention of Hypertension. The boarding tries to be simple and realistic for all that physicians whom have to face the hypertensive population in their clinical practice. The information is based in the most recent scientific evidence. These guides are principally directed to hypertensive population of emergent countries like Mexico. It is emphasized preventive health measures, the importance of the no pharmacological actions, such as good nutrition, exercise and changes in life style, (which ideally it must begin from very early ages). [quot ]We suggest that the changes in the style of life must be vigorous, continuous and systematized, with a real reinforcing by part of all the organisms related to the health education for all population (federal and private social organisms). It is the most important way to confront and prevent this pandemic of chronic diseases[quot ]. In this new edition the authors amplifies the information and importance on the matter. The preventive cardiology must contribute in multidisciplinary entailment. Based mainly on national data and the international scientific publications, we developed our own system of classification and risk stratification for the carrying people with hypertension, Called HTM (Arterial Hypertension in Mexico) index. Its principal of purpose this index is to keep in mind that the current approach of hypertension must be always multidisciplinary. The institutional committee of experts reviewed with rigorous methodology under the principles of the evidence-based medicine, both, national and international medical literature, with the purpose of adapting the concepts and guidelines for a better control and treatment of hypertension in Mexico. This work group recognizes that hypertension is not an isolated disease; therefore its approach must be in the context of the prevalence and interaction with other cardiovascular risk factors such as obesity, diabetes, dislipidemia and smoking among others. The urgent necessity is emphasized to approach in a concatenated form the diverse cardiovascular risk factors, since independently of which they share common pathophysiological mechanisms, its suitable identification and cont

Polimorfismos genéticos en enfermedades cardiovasculares: la experiencia en el Instituto Nacional de Cardiología Ignacio Chávez / Genetic polymorphisms in cardiovascular diseases: the experience in the National Institute of Cardiology Ignacio Chávez

The knowledge of the complete human genome sequence and the application of new molecular techniques is providing important information about the genetic markers associated with the development of several diseases. Cardiovascular diseases are of special interest for these studies since they are an important worldwide health problem. These diseases have a multifactorial etiology, therefore, many genetic and environmental factors participate to generate them. The identification of susceptibility genes has the potential to aid in the development of new treatments and to enhance the prediction of disease risk. Thus, the strategy has been to analyze polymorphisms presents in candidate genes coding for important proteins in the homeostatic system involved in maintaining cardiovascular health. Several studies have been reported in Caucasian, Asian and African populations, however, few data are available in the mexican population. The revision discusses recently published data of polymorphic markers associated with cardiovascular disease in the Mexican population.

Regulación antitrombótica por la fibrinólisis / Antithrombotic regulation by fibrinolytic system

In this work it is emphasized the presence of the fibrinolitico system in different physiological mechanisms, specially in the antithrombotic regulation of the hemostasis. It is described: the mechanism of activation of plasminogen by their activators as much on the fibrin as in the cells surface; the inhibition of the activators in different metabolic alterations.

A novel SCN5A deletion mutation in a child with ventricular tachycardia, recurrent aborted sudden death, and Brugada electrocardiographic pattern / Descripción de una nueva mutación (deleción) en el gen SCN5A en un niño con taquicardia ventricular, riesgo de muerte súbita, y cuadro electrocardiográfico de Brugada

A novel SCN5A mutation was found in a child with congenital sick sinus disease, a Brugada-like electrocardiogram and recurrent aborted sudden death. The mutation (L1821fs/10) is a 4 base pair deletion (TCTG) at position 5464-5467 in exon 28 of the gene. The novel mutation is predicted to produce a frameshift leading to a premature stop codon after ten missense amino acids upstream that did not allow the generation of the complete protein, and probably producing an incomplete and therefore non functional protein. The resulting alteration in sodium current could explain the clinical phenotype observed in this patient.

Bases moleculares de la insuficiencia cardíaca / Molecular bases of heart failure

Heart failure (HF) is a complex pathophysiologic state in which delivery of blood and nutrients is inadequate for tissue requirements. HF almost always arises in patients with previous cardiovascular disease such as acute myocardial infarction, atherosclerosis, cardiomyopathy, myocarditis, congenital malformations, or valvular disease. Recently, substantial progress has been made to understand the etiology, pathogenesis, and mechanisms of HF. Several inter-related mechanisms such as oxidative stress, signal transduction, abnormalities in intracellular calcium handling, mitochondrial dysfunction and inherited mutations have been proposed as the triggers of HF.

Detección de una mutación en el gen KCNQ1 (KvLQT1) causante de síndrome de Jervell, Lange-Nielsen en una familia mexicana / KCNQ 1 (KvLQT1) missense mutation causing congenital long QT syndrome (Jervell-Lange-Nielsen) in a Mexican family

BACKGROUND: Long QT syndromes (LQTS) are inherited cardiac disorders caused by mutations in the genes that encode sodium or potassium transmembrane ion channel proteins. More than 200 mutations, in at least six genes, have been found in these patients. The Jervell and Lange-Nielsen (JLN) syndrome is the recessive form of the disease and is associated with deafness. Few families with JLN syndrome and genetic studies are reported in the literature. METHODS: The KCNQ1 (KvLQT1) gene in a Mexican family with Jervell-Lange-Nielsen long QT syndrome was analyzed using an automated sequence method. RESULTS: A missense mutation was found in the three affected individuals. This mutation is associated with complete loss of channel function. Correlation with the phenotype showed a prolonged QTc interval and deafness in the two siblings homozygous to the mutation. The mother, who was heterozygous for the mutation, also had prolonged QTc interval without deafness. The father and younger brother had normal QTc intervals. The mutation was not found in 50 healthy controls studied. CONCLUSIONS: We describe for the first time a mutation in the KCNQ1 gene in a Mexican family with JLN long QT syndrome. This mutation produces an amino acid change (Gly-Arg) at protein level at the 168 residue. This mutation has been previously reported in Caucasian families with LQTS.