916 resultados para CHRONIC HEART-FAILURE
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BACKGROUND: Increased activity of single ventricular L-type Ca(2+)-channels (L-VDCC) is a hallmark in human heart failure. Recent findings suggest differential modulation by several auxiliary beta-subunits as a possible explanation. METHODS AND RESULTS: By molecular and functional analyses of human and murine ventricles, we find that enhanced L-VDCC activity is accompanied by altered expression pattern of auxiliary L-VDCC beta-subunit gene products. In HEK293-cells we show differential modulation of single L-VDCC activity by coexpression of several human cardiac beta-subunits: Unlike beta(1) or beta(3) isoforms, beta(2a) and beta(2b) induce a high-activity channel behavior typical of failing myocytes. In accordance, beta(2)-subunit mRNA and protein are up-regulated in failing human myocardium. In a model of heart failure we find that mice overexpressing the human cardiac Ca(V)1.2 also reveal increased single-channel activity and sarcolemmal beta(2) expression when entering into the maladaptive stage of heart failure. Interestingly, these animals, when still young and non-failing ("Adaptive Phase"), reveal the opposite phenotype, viz: reduced single-channel activity accompanied by lowered beta(2) expression. Additional evidence for the cause-effect relationship between beta(2)-subunit expression and single L-VDCC activity is provided by newly engineered, double-transgenic mice bearing both constitutive Ca(V)1.2 and inducible beta(2) cardiac overexpression. Here in non-failing hearts induction of beta(2)-subunit overexpression mimicked the increase of single L-VDCC activity observed in murine and human chronic heart failure. CONCLUSIONS: Our study presents evidence of the pathobiochemical relevance of beta(2)-subunits for the electrophysiological phenotype of cardiac L-VDCC and thus provides an explanation for the single L-VDCC gating observed in human and murine heart failure.
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Although experimental prevention studies have suggested therapeutic potential of endothelin (ET) antagonists for the treatment of heart failure, the results of clinical trials using ET antagonists on top of standard heart failure medications have been largely disappointing. This experimental study investigated the effects of chronic ET(A) receptor blockade in long-term survivors of myocardial infarction who had developed stable chronic heart failure in the absence of other treatments. Systolic blood pressure, heart rate, organ weights of the right atrium and ventricle, and the lungs were determined, and tissue ET-1 peptide levels were measured in cardiac tissue, lung, and aorta. The results show that chronic blockade of ET(A) receptors stabilizes systolic blood pressure and reverses the heart failure-induced weight increases of right heart chambers and lung. The changes observed occurred independently of tissue ET-1 concentrations and heart rate, suggesting mechanisms independent of local cardiac or pulmonary ET-1 synthesis, which are yet to be identified.
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With water immersion, gravity is partly eliminated, and the water exerts a pressure on the body surface. Consequently there is a blood volume shift from the periphery to the central circulation, resulting in marked volume loading of the thorax and heart. This paper presents a selection of published literature on water immersion, balneotherapy, aqua exercises, and swimming, in patients with left ventricular dysfunction (LVD) and/or stable chronic heart failure (CHF). Based on exploratory studies, central hemodynamic and neurohumoral responses of aquatic therapies will be illustrated. Major findings are: 1. In LVD and CHF, a positive effect of therapeutic warm-water tub bathing has been observed, which is assumed to be from afterload reduction due to peripheral vasodilatation caused by the warm water. 2. In coronary patients with LVD, at low-level water cycling the heart is working more efficiently than at lowlevel cycling outside of water. 3. In patients with previous extensive myocardial infarction, upright immersion to the neck resulted in temporary pathological increases in mean pulmonary artery pressure (mPAP) and mean pulmonary capillary pressures (mPCP). 4. Additionally, during slow swimming (20-25m/min) the mPAP and/or PCP were higher than during supine cycling outside water at a 100W load. 5. In CHF patients, neck- deep immersion resulted in a decrease or no change in stroke volume. 6. Although patients are hemodynamically compromised, they usually maintain a feeling of well-being during aquatic therapy. Based on these findings, clinical indications for aquatic therapies are proposed and ideas are presented to provoke further research.
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BACKGROUND: Muscular counterpulsation (MCP) was developed for circulatory assistance by stimulation of peripheral skeletal muscles. We report on a clinical MCP study in patients with and without chronic heart failure (CHF). METHODS AND RESULTS: MCP treatment was applied (30 patients treated, 25 controls, all under optimal therapy) for 30 minutes during eight days by an ECG-triggered, battery-powered, portable pulse generator with skin electrodes inducing light contractions of calf and thigh muscles, sequentially stimulated at early diastole. Hemodynamic parameters (ECG, blood pressure and echocardiography) were measured one day before and one day after the treatment period in two groups: Group 1 (9 MCP, 11 no MCP) with ejection fraction (EF) above 40% and Group 2 (21 MCP, 14 no MCP) below 40%. In Group 2 (all patients suffering from CHF) mean EF increased by 21% (p<0.001) and stroke volume by 13% (p<0.001), while end systolic volume decreased by 23% (p<0.001). In Group 1, the increase in EF (6%) and stroke volume (8%) was also significant (p<0.05) but less pronounced than in Group 2. Physical exercise duration and walking distance increased in Group 2 by 56% and 72%, respectively. CONCLUSIONS: Noninvasive MCP treatment for eight days substantially improves cardiac function and physical performance in patients with CHF.
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BACKGROUND: Exertional oscillatory ventilation (EOV) in heart failure may potentiate the negative effects of low cardiac output and high ventilation on exercise performance. We hypothesized that the presence of EOV might, per se, influence exercise capacity as evaluated by maximal cardiopulmonary exercise test. METHODS AND RESULTS: We identified 78 severe chronic heart failure patient pairs with and without EOV. Patients were matched for sex, age and peak oxygen consumption (VO2). Patients with EOV showed, for the same peak VO2, a lower workload (WL) at peak (DeltaWatts=5.8+/-23.0, P=0.027), a less efficient ventilation (higher VE/VCO2 slope: 38.0+/-8.3 vs. 32.8+/-6.3, P<0.001), lower peak exercise tidal volume (1.49+/-0.36 L vs. 1.61+/-0.46 L, P=0.015) and higher peak respiratory rate (34+/-7/min vs. 31+/-6/min, P=0.002). In 33 patients, EOV disappeared during exercise, whereas in 45 patients EOV persisted. Fifty percent of EOV disappearing patients had an increase in the VO2/WL relationship after EOV regression, consistent with a more efficient oxygen delivery to muscles. No cardiopulmonary exercise test parameter was associated with the different behaviour of VO2/WL. CONCLUSION: The presence of EOV negatively influences exercise performance of chronic heart failure patients likely because of an increased cost of breathing. EOV disappearance during exercise is associated with a more efficient oxygen delivery in several cases.
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AIMS: Data on moderately cold water immersion and occurrence of arrhythmias in chronic heart failure (CHF) patients are scarce. METHODS AND RESULTS: We examined 22 male patients, 12 with CHF [mean age 59 years, ejection fraction (EF) 32%, NYHA class II] and 10 patients with stable coronary artery disease (CAD) without CHF (mean age 65 years, EF 52%). Haemodynamic effects of water immersion and swimming in warm (32 degrees C) and moderately cold (22 degrees C) water were measured using an inert gas rebreathing method. The occurrence of arrhythmias during water activities was compared with those measured during a 24 h ECG recording. Rate pressure product during water immersion up to the chest was significantly higher in moderately cold (P = 0.043 in CHF, P = 0.028 in CAD patients) compared with warm water, but not during swimming. Rate pressure product reached 14200 in CAD and 12 400 in CHF patients during swimming. Changes in cardiac index (increase by 5-15%) and oxygen consumption (increase up to 20%) were of similar magnitude in moderately cold and warm water. Premature ventricular contractions (PVCs) increased significantly in moderately cold water from 15 +/- 41 to 76 +/- 163 beats per 30 min in CHF (P = 0.013) but not in CAD patients (20 +/- 33 vs. 42 +/- 125 beats per 30 min, P = 0.480). No ventricular tachycardia was noted. CONCLUSION: Patients with compensated CHF tolerate water immersion and swimming in moderately cold water well. However, the increase in PVCs raises concerns about the potential danger of high-grade ventricular arrhythmias.
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OBJECTIVE To determine the short- and long-term effects of an intensive, concentrated rehabilitation programme in patients with chronic heart failure. DESIGN Randomized controlled trial, with one-month and six-year evaluations. SETTING Residential rehabilitation centre in Switzerland. SUBJECTS Fifty patients with chronic heart failure, randomized to exercise or control groups. INTERVENTIONS A rehabilitation programme lasting one month, including educational sessions, a low-fat diet, and 2 hours of individually prescribed exercise daily. MAIN MEASURES Exercise test responses, health outcomes and physical activity patterns. RESULTS Peak Vo(2) increased 21.4% in the exercise group during the rehabilitation programme (P<0.05), whereas peak Vo(2) did not change among controls. After the six-year follow-up period, peak Vo(2) was only slightly higher than that at baseline in the trained group (7%, NS), while peak Vo(2) among controls was unchanged. During long-term follow-up, 9 and 12 patients died in the exercise and control groups, respectively (P = 0.63). At six years, physical activity patterns tended to be higher in the exercise group; the mean energy expenditure values over the last year were 2,704 +/- 1,970 and 2,085 +/- 1,522 kcal/week during recreational activities for the exercise and control groups, respectively. However, both groups were more active compared to energy expenditure prior to their cardiac event (P<0.001). CONCLUSIONS Six years after participation in a residential rehabilitation programme, patients with chronic heart failure had slightly better outcomes than control subjects, maintained exercise capacity and engaged in activities that exceed the minimal amount recommended by guidelines for cardiovascular health.
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Durante las últimas décadas se ha producido un fenómeno global de envejecimiento en la población. Esta tendencia se puede observar prácticamente en todos los países del mundo y se debe principalmente a los avances en la medicina, y a los descensos en las tasas de fertilidad y mortalidad. El envejecimiento de la población tiene un gran impacto en la salud de los ciudadanos, y a menudo es la causa de aparición de enfermedades crónicas. Este tipo de enfermedades supone una amenaza y una carga importantes para la sociedad, especialmente en aspectos como la mortalidad o los gastos en los sistemas sanitarios. Entre las enfermedades cardiovasculares, la insuficiencia cardíaca es probablemente la condición con mayor prevalencia y afecta a 23-26 millones de personas en todo el mundo. Normalmente, la insuficiencia cardíaca presenta un mal pronóstico y una tasa de supervivencia bajas, en algunos casos peores que algún tipo de cáncer. Además, suele ser la causa de hospitalizaciones frecuentes y es una de las enfermedades más costosas para los sistemas sanitarios. La tendencia al envejecimiento de la población y la creciente incidencia de las enfermedades crónicas están llevando a una situación en la que los sistemas de salud no son capaces de hacer frente a la demanda de la sociedad. Los servicios de salud existentes tendrán que adaptarse para ser efectivos y sostenibles en el futuro. Es necesario identificar nuevos paradigmas de cuidado de pacientes, así como mecanismos para la provisión de servicios que ayuden a transformar estos sistemas sanitarios. En este contexto, esta tesis se plantea la búsqueda de soluciones, basadas en las Tecnologías de la Información y la Comunicación (TIC), que contribuyan a realizar la transformación en los sistemas sanitarios. En concreto, la tesis se centra en abordar los problemas de una de las enfermedades con mayor impacto en estos sistemas: la insuficiencia cardíaca. Las siguientes hipótesis constituyen la base para la realización de este trabajo de investigación: 1. Es posible definir un modelo basado en el paradigma de lazo cerrado y herramientas TIC que formalice el diseño de mejores servicios para pacientes con insuficiencia cardíaca. 2. El modelo de lazo cerrado definido se puede utilizar para definir un servicio real que ayude a gestionar la insuficiencia cardíaca crónica. 3. La introducción, la adopción y el uso de un servicio basado en el modelo definido se traducirá en mejoras en el estado de salud de los pacientes que sufren insuficiencia cardíaca. a. La utilización de un sistema basado en el modelo de lazo cerrado definido mejorará la experiencia del usuario de los pacientes. La definición del modelo planteado se ha basado en el estándar ISO / EN 13940- Sistema de conceptos para dar soporte a la continuidad de la asistencia. Comprende un conjunto de conceptos, procesos, flujos de trabajo, y servicios como componentes principales, y representa una formalización de los servicios para los pacientes con insuficiencia cardíaca. Para evaluar el modelo definido se ha definido un servicio real basado en el mismo, además de la implementación de un sistema de apoyo a dicho servicio. El diseño e implementación de dicho sistema se realizó siguiendo la metodología de Diseño Orientado a Objetivos. El objetivo de la evaluación consistía en investigar el efecto que tiene un servicio basado en el modelo de lazo cerrado sobre el estado de salud de los pacientes con insuficiencia cardíaca. La evaluación se realizó en el marco de un estudio clínico observacional. El análisis de los resultados ha comprendido métodos de análisis cuantitativos y cualitativos. El análisis cuantitativo se ha centrado en determinar el estado de salud de los pacientes en base a datos objetivos (obtenidos en pruebas de laboratorio o exámenes médicos). Para realizar este análisis se definieron dos índices específicos: el índice de estabilidad y el índice de la evolución del estado de salud. El análisis cualitativo ha evaluado la autopercepción del estado de salud de los pacientes en términos de calidad de vida, auto-cuidado, el conocimiento, la ansiedad y la depresión, así como niveles de conocimiento. Se ha basado en los datos recogidos mediante varios cuestionarios o instrumentos estándar (i.e. EQ-5D, la Escala de Ansiedad y Depresión (HADS), el Cuestionario de Cardiomiopatía de Kansas City (KCCQ), la Escala Holandesa de Conocimiento de Insuficiencia Cardíaca (DHFKS), y la Escala Europea de Autocuidado en Insuficiencia Cardíaca (EHFScBS), así como cuestionarios dedicados no estandarizados de experiencia de usuario. Los resultados obtenidos en ambos análisis, cuantitativo y cualitativo, se compararon con el fin de evaluar la correlación entre el estado de salud objetivo y subjetivo de los pacientes. Los resultados de la validación demostraron que el modelo propuesto tiene efectos positivos en el cuidado de los pacientes con insuficiencia cardíaca y contribuye a mejorar su estado de salud. Asimismo, ratificaron al modelo como instrumento válido para la definición de servicios mejorados para la gestión de esta enfermedad. ABSTRACT During the last decades we have witnessed a global aging phenomenon in the population. This can be observed in practically every country in the world, and it is mainly caused by the advances in medicine, and the decrease of mortality and fertility rates. Population aging has an important impact on citizens’ health and it is often the cause for chronic diseases, which constitute global burden and threat to the society in terms of mortality and healthcare expenditure. Among chronic diseases, Chronic Heart Failure (CHF) or Heart Failure (HF) is probably the one with highest prevalence, affecting between 23 and 26 million people worldwide. Heart failure is a chronic, long-term and serious condition with very poor prognosis and worse survival rates than some type of cancers. Additionally, it is often the cause of frequent hospitalizations and one of the most expensive conditions for the healthcare systems. The aging trends in the population and the increasing incidence of chronic diseases are leading to a situation where healthcare systems are not able to cope with the society demand. Current healthcare services will have to be adapted and redefined in order to be effective and sustainable in the future. There is a need to find new paradigms for patients’ care, and to identify new mechanisms for services’ provision that help to transform the healthcare systems. In this context, this thesis aims to explore new solutions, based on ICT, that contribute to achieve the needed transformation within the healthcare systems. In particular, it focuses on addressing the problems of one of the diseases with higher impact within these systems: Heart Failure. The following hypotheses represent the basis to the elaboration of this research: 1. It is possible to define a model based on a closed-loop paradigm and ICT tools that formalises the design of enhanced healthcare services for chronic heart failure patients. 2. The described closed-loop model can be exemplified in a real service that supports the management of chronic heart failure disease. 3. The introduction, adoption and use of a service based on the outlined model will result in improvements in the health status of patients suffering heart failure. 4. The user experience of patients when utilizing a system based on the defined closed-loop model will be enhanced. The definition of the closed-loop model for health care support of heart failure patients have been based on the standard ISO/EN 13940 System of concepts to support continuity of care. It includes a set of concept, processes and workflows, and services as main components, and it represent a formalization of services for heart failure patients. In order to be validated, the proposed closed-loop model has been instantiated into a real service and a supporting IT system. The design and implementation of the system followed the user centred design methodology Goal Oriented Design. The validation, that included an observational clinical study, aimed to investigate the effect that a service based on the closed-loop model had on heart failure patients’ health status. The analysis of results comprised quantitative and qualitative analysis methods. The quantitative analysis was focused on determining the health status of patients based on objective data (obtained in lab tests or physical examinations). Two specific indexes where defined and considered in this analysis: the stability index and the health status evolution index. The qualitative analysis assessed the self-perception of patients’ health status in terms of quality of life, self-care, knowledge, anxiety and depression, as well as knowledge levels. It was based on the data gathered through several standard instruments (i.e. EQ-5D, the Hospital Anxiety and Depression Scale, the Kansas City Cardiomyopathy Questionnaire, the Dutch Heart Failure Knowledge Scale, and the European Heart Failure Self-care Behaviour Scale) as well as dedicated non-standardized user experience questionnaires. The results obtained in both analyses, quantitative and qualitative, were compared in order to assess the correlation between the objective and subjective health status of patients. The results of the validation showed that the proposed model contributed to improve the health status of the patients and had a positive effect on the patients’ care. It also proved that the model is a valid instrument for designing enhanced healthcare services for heart failure patients.
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Background. Australia, like other countries, is experiencing an epidemic of heart failure (HF). However, given the lack of national and population-based datasets collating detailed cardiovascular-specific morbidity and mortality outcomes, quantifying the specific burden imposed by HF has been difficult. Methods. Australian Bureau of Statistics (ABS data) for the year 2000 were used in combination with contemporary, well-validated population-based epidemiologic data to estimate the number of individuals with symptomatic and asymptomatic HF related to both preserved (diastolic dysfunction) and impaired left ventricular systolic (dys)function (LVSD) and rates of HF-related hospitalisation. Results. In 2000, we estimate that around 325,000 Australians (58% male) had symptomatic HF associated with both LVSD and diastolic dysfunction and an additional 214,000 with asymptomatic LVSD. 140,000 (26%) live in rural and remote regions, distal to specialist health care services. There was an estimated 22,000 incidents of admissions for congestive heart failure and approximately 100,000 admissions associated with this syndrome overall. Conclusion. Australia is in the midst of a HF epidemic that continues to grow. Overall, it probably contributes to over 1.4 million days of hospitalization at a cost of more than $1 billion. A national response to further quantify and address this enormous health problem is required.
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As suggested by studies that have examined the economic burden imposed by heart failure and, more specifically where the greatest expenditure occurs, the key to cost-effectively minimising the impact of a sustained heart failure epidemic is to minimise recurrent hospital use-even at the expense of increasing levels of community-based care and prescribed pharmacotherapy [Mark DB. Economics of treating heart failure. Am J Cardiol 1997;80:33H-38H; Weintraub WS, Cole J, Tooley JF. Cost and cost-effectiveness studies in heart failure research. Am Heart J 2002;143:565-76]. This paper examines the potential cost-benefits of applying specialist heart failure programs of care and the range of financial issues that need to be considered when establishing a formal heart failure service. (C) 2005 European Society of Cardiology. Published by Elsevier B.V.
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Background: The aim of this study was to determine the effects of carvedilol on the costs related to the treatment of severe chronic heart failure (CHF). Methods: Costs for the treatment for heart failure within the National Health Service (NHS) in the United Kingdom (UK) were applied to resource utilisation data prospectively collected in all patients randomized into the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) Study. Unit-specific, per them (hospital bed day) costs were used to calculate expenditures due to hospitalizations. We also included costs of carvedilol treatment, general practitioner surgery/office visits, hospital out-patient clinic visits and nursing home care based on estimates derived from validated patterns of clinical practice in the UK. Results: The estimated cost of carvedilol therapy and related ambulatory care for the 1156 patients assigned to active treatment was 530,771 pound (44.89 pound per patient/month of follow-up). However, patients assigned to carvedilol were hospitalised less often and accumulated fewer and less expensive days of admission. Consequently, the total estimated cost of hospital care was 3.49 pound million in the carvedilol group compared with 4.24 pound million for the 1133 patients in the placebo arm. The cost of post-discharge care was also less in the carvedilol than in the placebo group (479,200 pound vs. 548,300) pound. Overall, the cost per patient treated in the carvedilol group was 3948 pound compared to 4279 pound in the placebo group. This equated to a cost of 385.98 pound vs. 434.18 pound, respectively, per patient/month of follow-up: an 11.1% reduction in health care costs in favour of carvedilol. Conclusions: These findings suggest that not only can carvedilol treatment increase survival and reduce hospital admissions in patients with severe CHF but that it can also cut costs in the process.
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Reactive oxygen species play important roles in the pathophysiology of chronic heart failure secondary to chronic left ventricular hypertrophy or myocardial infarction. Reactive oxygen species influence several components of the phenotype of the failing heart, including contractile function, interstitial fibrosis, endothelial dysfunction and myocyte hypertrophy. Recent studies implicate the production of reactive oxygen species by a family of NADPH oxidases in these effects. NADPH oxidases are activated in an isoform-specific manner by many pathophysiological stimuli and exert distinct downstream effects. Understanding NADPH oxidase activation and regulation, and their downstream effectors, could help to develop novel therapeutic targets.
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OBJECTIVE: To differentiate the nature of functional cardiorespiratory limitations during exercise in individuals with chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF) and to determine indicators that may help their classifications. METHODS: The study comprised 40 patients: 23 with COPD and 17 with CHF. All individuals underwent maximal cardiopulmonary exercise testing on a treadmill. RESULTS: The values of peak gas exchange ratio (R peak), peak carbon dioxide production (VCO2 peak), and peak oxygen ventilatory equivalent (V E O2 peak) were higher in the patients with CHF than in those with COPD, and, therefore, those were the variables that characterized the differences between the groups. For group classification, the differentiating functions with the R peak, VCO2 peak (L/min), and V E O2 peak variables were used as follows: group COPD: - 44.886 + 78.832 x R peak + 5.442 x VCO2 peak + 0.336 x V E O2 peak; group CHF: - 69.251 + 89.740 x R peak + 8.461 x VCO2 peak + 0.574 x V E O2 peak. The differentiating function, whose result is greater, correctly classifies the patient's group as 90%. CONCLUSION: The R peak, VCO2 peak, and V E O2 peak values may be used to identify the cause of the functional cardiorespiratory limitations in patients with COPD and CHF.
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Catopril, an inhibitor of angiotensin converting enzyme, was given orally during cardiac catheterisation to 6 normotensive patients with refractory congestive heart-failure. 60--180 minutes after administration of 25 mg captopril, arterial pressure fell by 25%, cardiac index rose by 38%, and left-ventricular pressure and right-atrial pressure fell by 25% and 40% respectively. Plasma-renin activity rose while plasma noradrenaline and aldosterone fell. These data suggest that, in the short term, captopril can reduce both preload and afterload, and improve cardiac function, in refractory congestive heart-failure.
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BACKGROUND: Chronic kidney disease (CKD) has been linked to higher heart failure (HF) risk. Anemia is a common consequence of CKD, and recent evidence suggests that anemia is a risk factor for HF. The purpose of this study was to examine among patients with HF, the association between CKD, anemia and inhospital mortality and early readmission. METHODS: We performed a retrospective cohort study in two Swiss university hospitals. Subjects were selected based the presence of ICD-10 HF codes in 1999. We recorded demographic characteristics and risk factors for HF. CKD was defined as a serum creatinine > or = 124 956;mol/L for women and > or = 133 micromol/L for men. The main outcome measures were inhospital mortality and thirty-day readmissions. RESULTS: Among 955 eligible patients hospitalized with heart failure, 23.0% had CKD. Twenty percent and 6.1% of individuals with and without CKD, respectively, died at the hospital (p < 0.0001). Overall, after adjustment for other patient factors, creatinine and hemoglobin were associated with an increased risk of death at the hospital, and hemoglobin was related to early readmission. CONCLUSION: Both CKD and anemia are frequent among older patients with heart failure and are predictors of adverse outcomes, independent of other known risk factors for heart failure.