Phenotype and progression among patients with dilated cardiomyopathy and RBM20 mutations.

BACKGROUND: Over 70 genes that encode different cell components have been involved in the aetiology of dilated cardiomyopathy. Genotype-phenotype interactions are an unsolved problem, and to a large extent the effects of mutations in the expression mechanisms involved in the disease remain unknown, although associations are increasingly being established which have clinical and prognostic implications. METHODS AND RESULTS: The objective of our work was to describe our population that has cardiomyopathy associated with mutations in the gene RBM20, and study the genotype-phenotype relationship. We studied 8 cases undergoing follow-up at our Unit, and collected data for demographic, clinical and diagnostic testing variables. The mean age on diagnosis was 55 years [52-59], with a median follow-up of 31.5 months [26.0-67.3]. It is worth noting that 62.5% of the patients in our group had a history of cardiomyopathy in first degree relatives, and 37.5% of them had a family history of sudden death. One of the genetic variations of the sample was shared by three subjects who had no apparent family relationship with each other, and this variation had not been described in controls. It is also interesting that arrhythmic events were found in 37.5% of the sample, and 50% of patients had an indication for implantable cardiac defibrillator. CONCLUSION: This is the first analysis of patients with RBM20 mutations conducted in our country, and it indicates a profile with prominent arrhythmogenesis, a high penetrance of familial cardiomyopathy, and sudden death.

Overexpression of scavenger receptor and infiltration of macrophage in epicardial adipose tissue of patients with ischemic heart disease and diabetes.

BACKGROUND: Oxidized low-density lipoproteins and scavenger receptors (SRs) play an important role in the formation and development of atherosclerotic plaques. However, little is known about their presence in epicardial adipose tissue (EAT). The objective of the study was to evaluate the mRNA expression of different SRs in EAT of patients with ischemic heart disease (IHD), stratifying by diabetes status and its association with clinical and biochemical variables. METHODS: We analyzed the mRNA expression of SRs (LOX-1, MSR1, CXCL16, CD36 and CL-P1) and macrophage markers (CD68, CD11c and CD206) in EAT from 45 patients with IHD (23 with type 2 diabetes mellitus (T2DM) and 22 without T2DM) and 23 controls without IHD or T2DM. RESULTS: LOX-1, CL-P1, CD68 and CD11c mRNA expression were significantly higher in diabetic patients with IHD when compared with those without T2DM and control patients. MSR1, CXCL16, CD36 and CD206 showed no significant differences. In IHD patients, LOX-1 (OR 2.9; 95% CI 1.6-6.7; P = 0.019) and CD68 mRNA expression (OR 1.7; 95% CI 0.98-4.5; P = 0.049) were identified as independent risk factors associated with T2DM. Glucose and glycated hemoglobin were also shown to be risk factors. CONCLUSIONS: SRs mRNA expression is found in EAT. LOX-1 and CD68 and were higher in IHD patients with T2DM and were identified as a cardiovascular risk factor of T2DM. This study suggests the importance of EAT in coronary atherosclerosis among patients with T2DM.

Rentabilidad del estudio genético mediante técnicas de next-generation sequencing masiva de pacientes con miocardiopatía arritmogénica de alto riesgo / Usefulness of genetic study by next-generation sequencing in high-risk arrhythmogenic cardiomyopathy

Introducción y objetivos: La miocardiopatía arritmogénica del ventrículo derecho (MCAVD) es una cardiopatía hereditaria definida por la sustitución progresiva de miocardio ventricular derecho por tejido fibroadiposo. Es causa frecuente de la muerte súbita de jóvenes atletas. El objetivo del presente estudio es conocer la incidencia de variantes desmosómicas patogénicas o probablemente patogénicas en pacientes con MCAVD definitiva de alto riesgo. Métodos: El estudio de cohortes retrospectivo observacional incluyó a 36 pacientes diagnosticados de MCAVD definitiva de alto riesgo en nuestro hospital entre enero de 1998 y enero de 2015. El análisis genético se realizó con next-generation sequencing. Resultados: La mayoría eran varones (28 pacientes, 78%) con una media de edad al diagnóstico de 45 ± 18 años. Se detectó al menos 1 variante desmosómica patogénica o probablemente patogénica en 26 de los 35 casos índice (74%): 5 nonsense, 14 frameshift, 1 splice y 6 missense. En 15 pacientes (71%) se encontraron mutaciones nuevas. La presencia o la ausencia de mutaciones desmosómicas o la naturaleza de estas no se asociaron con características electrocardiográficas, clínicas, arrítmicas, anatómicas o pronósticas específicas. Conclusiones: La incidencia de variantes desmosómicas patogénicas o probablemente patogénicas en MCAVD definitiva de alto riesgo fue muy alta, con mayoría de mutaciones que causan truncamiento. La presencia de mutaciones desmosómicas no se asoció con el pronóstico

Introduction and objectives: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by progressive fibrofatty replacement of predominantly right ventricular myocardium. This cardiomyopathy is a frequent cause of sudden cardiac death in young people and athletes. The aim of our study was to determine the incidence of pathological or likely pathological desmosomal mutations in patients with high-risk definite ARVC. Methods: This was an observational, retrospective cohort study, which included 36 patients diagnosed with high-risk ARVC in our hospital between January 1998 and January 2015. Genetic analysis was performed using next-generation sequencing. Results: Most patients were male (28 patients, 78%) with a mean age at diagnosis of 45 ± 18 years. A pathogenic or probably pathogenic desmosomal mutation was detected in 26 of the 35 index cases (74%): 5 nonsense, 14 frameshift, 1 splice, and 6 missense. Novel mutations were found in 15 patients (71%). The presence or absence of desmosomal mutations causing the disease and the type of mutation were not associated with specific electrocardiographic, clinical, arrhythmic, anatomic, or prognostic characteristics. Conclusions: The incidence of pathological or likely pathological desmosomal mutations in ARVC is very high, with most mutations causing truncation. The presence of desmosomal mutations was not associated with prognosis

Impact of dynamic physical exercise on high-risk definite arrhythmogenic right ventricular cardiomyopathy.

INTRODUCTION: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited cardiomyopathy characterized by ventricular arrhythmias and heart failure. The variable phenotype suggesting that determined environmental factors may have an influence. The aim of our study was to discover the impact of the dynamic physical activity on patients with high-risk definite ARVC/D. METHODS AND RESULTS: Collection of data on physical activity at the time of diagnosis was conducted at an in-person clinical interview. The intensity of the activity was classified in accordance with the mean frequency of weekly physical exercise sessions in the 10 years before diagnosis and into the following three groups of dynamic activity: high/competitive (>3 h/wk), moderate (1 to 3 h) and minimal/inactive (<1 h). Seventeen patients practiced high dynamic physical activities. The intensity of dynamic activity was classified into three groups: 8 of high intensity, 9 moderate, and 19 inactive. The first major arrhythmic event and occurrence of severe right ventricular dysfunction were earlier in the high-intensity exercise group, followed by the moderate intensity group and at a later age in the low-intensity/inactive group. CONCLUSIONS: Dynamic exercise could be directly associated with the severity of the phenotype in relation to the precocity of major ventricular arrhythmic events and right ventricular systolic dysfunction in patients with high-risk definite ARVC/D.

Usefulness of Genetic Study by Next-generation Sequencing in High-risk Arrhythmogenic Cardiomyopathy.

INTRODUCTION AND OBJECTIVES: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by progressive fibrofatty replacement of predominantly right ventricular myocardium. This cardiomyopathy is a frequent cause of sudden cardiac death in young people and athletes. The aim of our study was to determine the incidence of pathological or likely pathological desmosomal mutations in patients with high-risk definite ARVC. METHODS: This was an observational, retrospective cohort study, which included 36 patients diagnosed with high-risk ARVC in our hospital between January 1998 and January 2015. Genetic analysis was performed using next-generation sequencing. RESULTS: Most patients were male (28 patients, 78%) with a mean age at diagnosis of 45 ± 18 years. A pathogenic or probably pathogenic desmosomal mutation was detected in 26 of the 35 index cases (74%): 5 nonsense, 14 frameshift, 1 splice, and 6 missense. Novel mutations were found in 15 patients (71%). The presence or absence of desmosomal mutations causing the disease and the type of mutation were not associated with specific electrocardiographic, clinical, arrhythmic, anatomic, or prognostic characteristics. CONCLUSIONS: The incidence of pathological or likely pathological desmosomal mutations in ARVC is very high, with most mutations causing truncation. The presence of desmosomal mutations was not associated with prognosis.

Expression of epicardial adipose tissue thermogenic genes in patients with reduced and preserved ejection fraction heart failure.

Epicardial adipose tissue has been proposed to participate in the pathogenesis of heart failure. The aim of our study was to assess the expression of thermogenic genes (Uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), and PR-domain-missing 16 (PRDM16) in epicardial adipose tissue in patients with heart failure, stablishing the difference according to left ventricular ejection fraction (reduced or preserved). Among the 75 patients in our study, 42.7% (n=32) had reduced left ventricular ejection fraction. UCP1, PGC1α and PRDM16 mRNA in EAT were significantly lower in patients with reduced left ventricular ejection fraction. Multiple regression analysis showed that age, male gender, body max index, presence of obesity, type-2-diabetes mellitus, hypertension and coronary artery disease and left ventricular ejection fraction were associated with the expression levels of UCP1, PGC1α and PRDM16 mRNA. Thermogenic genes expressions in epicardial adipose tissue (UCP1: OR 0.617, 95%CI 0.103-0.989, p=0.042; PGC1α: OR 0.416, 95%CI 0.171-0.912, p=0.031; PRDM16: OR 0.643, 95%CI 0.116-0.997, p=0.044) were showed as protective factors against the presence of heart failure with reduced left ventricular ejection fraction, and age (OR 1.643, 95%CI 1.001-3.143, p=0.026), presence of coronary artery disease (OR 6.743, 95%CI 1.932-15.301, p<0.001) and type-2-diabetes mellitus (OR 4.031, 95%CI 1.099-7.231, p<0.001) were associated as risk factors. The adequate expression of thermogenic genes has been shown as possible protective factors against heart failure with reduced ejection fraction, suggesting that a loss of functional epicardial adipose tissue brown-like features would participate in a deleterious manner on heart metabolism. Thermogenic genes could represent a future novel therapeutic target in heart failure.