Miocardiopatía dilatada: aspectos genéticos, infecciosos, inflamatorios y del sistema inmune / Dilated cardiomyopathy: genetics, infectious, inflammatory and immune aspects

En la última década se ha producido un incremento sustancial en el conocimiento de las bases genéticas de las cardiomiopatías, en consideración a lo cual las Sociedades Americanas y Europea de Cardiología, han propuesto una nueva clasificación con el fin de incluir tales aspectos, Aunque se carece de datos precisos, aproximadamente el 30% de los pacientes con miocardiopatías referidos para pruebas genéticas presentan una variante genética patogénica. En la herencia de la miocardiopatía dilatada familiar, la modalidad predominante es la autosómica dominante, siendo mucho menos frecuentes las ligadas al cromosoma X, la herencia autosómica recesiva y la mitocondrial. A su vez, pruebas provenientes de ensayos clínicos y experimentales indican que la infección, la inflamación y el sistema inmunológico están de alguna manera interrelacionados en los mecanismos patogénicos implicados en la miocardiopatía dilatada, No hay duda que en un futuro próximo las mejoras en la secuenciación de genes y el mayor conocimiento de la patogenia influirán decididamente en el diagnóstico, evaluación y tratamiento de esta entidad.

In the last time, a substantial increase in the knowledge of the genetic basis of cardiomyopathy has occurred. Therefore in the last decade the American Heart Association, the American College of Cardiology and the European Society of Cardiology have proposed a new revision of the classification of cardiomyopathies in order to include the genetic basis on the etiology, Although precise data are lacking, approximately 30% of patients currently referred for clinical genetic testing will be found to have a pathogenic genetic variant. The predominant mode of inheritance for familial dilated cardiomyopathy is autosomal dominant, with X linked autosomal recessive and mitochondrial inheritance being less frequent. Evidence from experimental and clinical trials indicates that infection, inflammation and the immune system are in some way interrelated on the pathogenic mechanisms involved in the dilated cardiomyopathy, There is no doubt that in the future, improvements in sequencing genes and insight into pathogenesis will influence the diagnosis, evaluation and management of familial dilated cardiomyopathy.

[Predictors of hospital death and prolonged hospitalization in patients with cardiac failure in Chilean hospitals]. / Predictores de mortalidad intrahospitalaria y hospitalización prolongada en la insuficiencia cardíaca: resultados preliminares del registro nacional de insuficiencia cardíaca. Grupo ICARO.

BACKGROUND: Heart failure (HF) is one of the most common causes for hospital admission. AIM: To evaluate clinical predictors of mortality and prolonged hospital stay among patients admitted for HF in Chilean hospitals. PATIENTS AND METHODS: Prospective registry of 14 centers. Patients admitted for HF in functional class III and IV were included. Epidemiological, clinical data, functional class, decompensation cause, electrocardiogram, echocardiogram, treatment and evolution were registered. The endpoint was hospital death and hospital stay greater than 10 days. RESULTS: Data from 646 patients (mean age 69+/-13 years, 56% men) was collected. The main etiologies of HF were hypertensive in 29.6%, ischemic in 27.1% and valvular in 20%. Mean hospital stay was 10+/-9 days and mortality was 5.6%. Independent predictors of death and prolonged hospital stay were serum sodium <130 mEq/L at admission (odds ratio (OR) 2.6, confidence interval (CI) = 1.2-5.9), serum albumin <3 g/dL (OR 3.2, CI= 1.42-7.2) and a history of hypertension (OR 1.98, CI = 1.1-3.85). The model predicted correctly the occurrence of the endpoint in 67% of cases. CONCLUSIONS: In patients admitted for worsening HF, low serum sodium, decreased serum albumin on admission and a history of hypertension increase the risk for in-hospital death and prolonged hospital stay.

Predictores de mortalidad intrahospitalaria y hospitalización prolongada en la insuficiencia cardíaca: resultados preliminares del registro nacional de insuficiencia cardíaca. Grupo ICARO / Predictors of hospital death and prolonged hospitalization in patients with cardiac failure in Chilean hospitals

Background: Heart failure (HF) is one of the most common causes for hospital admission. Aim: To evaluate clinical predictors of mortality and prolonged hospital stay among patients admitted for HF in Chilean hospitals. Patients and Methods: Prospective registry of 14 centers. Patients admitted for HF in functional class III and IV were included. Epidemiological, clinical data, functional class, decompensation cause, electrocardiogram, echocardiogram, treatment and evolution were registered. The endpoint was hospital death and hospital stay greater than 10 days. Results: Data from 646 patients (mean age 69±13 years, 56 percent men) was collected. The main etiologies of HF were hypertensive in 29.6 percent, ischemic in 27.1 percent and valvular in 20 percent. Mean hospital stay was 10±9 days and mortality was 5.6 percent. Independent predictors of death and prolonged hospital stay were serum sodium <130 mEq/L at admission (odds ratio (OR) 2.6, confidence interval (CI)= 1.2-5.9), serum albumin <3 g/dL (OR 3.2, CI= 1.42-7.2) and a history of hypertension (OR 1.98, CI=1.1-3.85). The model predicted correctly the occurrence of the endpoint in 67 percent of cases. Conclusions: In patients admitted for worsening HF, low serum sodium, decreased serum albumin on admission and a history of hypertension increase the risk for in-hospital death and prolonged hospital stay.

[Characteristics of heart failure with preserved ejection fraction: results of the Chilean national registry of heart failure, ICARO]. / Características de la insuficiencia cardíaca en pacientes con fracción de eyección preservada: resultados del registro Nacional de insuficiencia Cardíaca, grupo ICARO.

BACKGROUND: Heart failure (HF) with preserved ejection fraction (EF) is a condition of growing interest due to its high prevalence and difficult management. AIM: To evaluate the clinical profile of patients hospitalized with HF and preserved EF in Chilean hospitals. MATERIAL AND METHODS: Prospective registry of 15 centers. Among 649 patients hospitalized in functional class III and IV, an echocardiogram was performed to 353. Preserved EF was defined quantitatively as an EF >50%. RESULTS: Out the 353 patients, 45% presented an EF >50%. Mean age in patients with EF >50 and -50% was 66+/-13 and 67+/-13 years, respectively. Among patients with HF and EF >50%, the proportion of women was higher (73.7 and 36.3%, p <0.001), the proportion of patients with a history of hypertension (76.8 and 65.5%, p <0.05) and the presence of atrial fibrillation was also higher (62.3 and 47.8%, p <0.01) and a history of myocardial infarction was lower (17.1 and 29.5%, p <0.05). The diastolic diameter of the left ventricle was significantly lower in HF with preserved EF (51.0+10 and 63.5+10 mm respectively, p <0.001). No differences in the length of hospital stay and mortality were observed between HF with depressed and preserved EF. Female gender was an independent predictor for the presence of HF with preserved EF (Odds ratio: 2.62; confidence intervals: 1.1-6.1). CONCLUSIONS: HF and preserved EF is common among hospitalized patients, particularly in women and subjects with a history of hypertension and atrial fibrillation. Hospitalization length and mortality were similar in patients with either preserved or depressed EF.

Características de la insuficiencia cardíaca en pacientes con fracción de eyección preservada: Resultados del Registro Nacional de Insuficiencia Cardíaca, Grupo ICARO / Characteristics of heart failure with preserved ejection fraction: Results of the Chilean National Registry of Heart Failure, ICARO

Background: Heart failure (HF) with preserved ejection fraction (EF) is a condition of growing interest due to its high prevalence and difficult management. Aim: To evaluate the clinical profile of patients hospitalized with HF and preserved EF in Chilean hospitals. Material and Methods: Prospective registry of 15 centers. Among 649 patients hospitalized in functional class III and IV, an echocardiogram was performed to 353. Preserved EF was defined quantitatively as an EF >50%. Results: Out the 353 patients, 45% presented an EF >50%. Mean age in patients with EF >50 and ­50% was 66±13 and 67±13 years, respectively. Among patients with HF and EF >50%, the proportion of women was higher (73.7 and 36.3%, p <0.001), the proportion of patients with a history of hypertension (76.8 and 65.5%, p <0.05) and the presence of atrial fibrillation was also higher (62.3 and 47.8%, p <0.01) and a history of myocardial infarction was lower (17.1 and 29.5%, p <0.05). The diastolic diameter of the left ventricle was significantly lower in HF with preserved EF (51.0+10 and 63.5+10 mm respectively, p <0.001). No differences in the length of hospital stay and mortality were observed between HF with depressed and preserved EF. Female gender was an independent predictor for the presence of HF with preserved EF (Odds ratio: 2.62; confidence intervals: 1.1-6.1). Conclusions: HF and preserved EF is common among hospitalized patients, particularly in women and subjects with a history of hypertension and atrial fibrillation. Hospitalization length and mortality were similar in patients with either preserved or depressed EF.

Insuficiencia cardíaca en hospitales chilenos: resultados del Registro Nacional de Insuficiencia Cardíaca, Grupo ICARO / Cardiac failure in Chilean hospitals: results of the National Registry of Heart Failure, ICARO

Background: Heart failure (HF) is a major public health problem. In Chile hospitalized patients due to HF have not been characterized. Aim: To evaluate clinical profile and outcome of patients hospitalized for heart failure in Chilean hospitals. Patients and Methods: Prospective registry of 14 centers. Patients hospitalized for HF in functional class III and IV were included. Epidemiological and clinical data, functional class, type of presentation, decompensation cause, electrocardiogram, echocardiogram, treatment and evolution were registered. Results: Three hundred seventy two patients aged 69±13 years old, 59 percent men, were assessed. The main etiologies of HF were ischemic in 31.6 percent, hypertensive in 35.2 percent, valvular in 14.9 percent and idiopathic in 7.4 percent. There was a history of hypertension 69 percent, diabetes in 35 percent, myocardial infarction in 22 percent, atrial fibrillation (AF) in 28 percent. The presentation form of HF was chronic decompensated in 86 percent, acute in 12 percent, refractory in 2 percent. The causes of decompensation were non compliance with diet or medical prescriptions in 28 percent, infections in 22 percent and AF 17 percent. ECG showed AF in 36 percent and left bundle branch block in 16 percent. Echocardiography was performed in 52 percent of the patients, 69 percent had left ventricular ejection fraction <40 percent. On admission, 39 percent received angiotensin converting enzyme (ACE) inhibitors, 15 percent beta-blocker, 25 percent digoxin, 16 percent spironolactone and 53 percent furosemide. The mean hospital stay was 11±10 days and mortality was 4.5 percent. Conclusions: The elderly is the age group most commonly admitted to hospital due to HF. The main etiologies were ischemic and hypertensive. The main causes for decompensations were noncompliance with diet or medical prescriptions and infections. A significant proportion had a relatively well preserved ventricular systolic function (Rev Méd Chile 2004; 132: 655-62).

Variabilidad de la frecuencia cardíaca: sus fundamentos fisiopatológicos y su utilidad como índice pronóstico post-infarto agudo del miocardio / Variability of cardiac frequency: it physiopathological basis and it utility as pronostic index on post myocardial acute infarction

The analysis of heart rate variability studies the normal oscillatory changes of the cardiac cycle. These changes are periodicals or incidental and are controlled by humoral, sympathetic and parasympathetic stimuli. Time domain analysis variations of cardiac cycle using the standard deviation of RR intervals in 24 hours (SDRR) and the percentage of difference between adjacent normal RR intervals of more than 50 ms (pNN50). Frequency domain, converts beat to beat fluctuation of heart rate into different components of frequency by a fast Fourier transformation. They are classified, according to their magnitude, in high frequency (>0.15 Hz), low frequency (0.04-0.15 Hz), very low frequency (0.003-0.04 Hz) and extremely low frequency (<0.003 Hz). The high frequency fluctuations are predominantly related to parasympathetic activity. The physiology of very low and extremely loe frequency fluctuations remain unclear. Many reports have shown that a decrease in heart rate variability after myocardial infarction may independently identify patients at risk for sudden death. However, the physiopathological basis of these findings is not yet elucidated