Russell C. Davis

Prevalence of left-ventricular systolic dysfunction and heart failure in the Echocardiographic Heart of England Screening study: a population based study

BACKGROUND Accurate data for prevalence rates for heart failure due to various causes, and for left-ventricular systolic dysfunction in all adults are unavailable. Our aim was to assess prevalence of left-ventricular systolic dysfunction and heart failure in a large representative adult population in England. METHODS Of 6286 randomly selected patients aged 45 years and older, 3960 (63%) participated in the study. They came from 16 randomly selected general practices. We assessed patients by history and examination, electrocardiography, and echocardiography. Prevalence of left-ventricular systolic dysfunction (defined as ejection fraction <40%) and heart failure was calculated for the overall population on the basis of strict criteria and, when necessary, adjudication by a panel. FINDINGS Left-ventricular systolic dysfunction was diagnosed in 72 (1.8% [95% CI 1.4-2.3]) participants, half of whom had no symptoms. Borderline left-ventricular function (ejection fraction 40-50%) was seen in 139 patients (3.5% [3.0-4.1]). Definite heart failure was seen in 92 (2.3%, [1.9-2.8]) and was associated with an ejection fraction of less than 40% in 38 (41%) patients, atrial fibrillation in 30 (33%), and valve disease in 24 (26%). Probable heart failure was seen in a further 32 (0.8% [0.6-1.1]) patients. In total, 124 (3.1% [2.6-3.7]) patients aged 45 years or older had definite or probable heart failure. INTERPRETATION Heart failure is often misdiagnosed or underdiagnosed in primary care. Our results suggest that assessment of left-ventricular function in patients with suspected heart failure could lead to more effective diagnosis and treatment of this disorder.

Reliability of N-terminal pro-brain natriuretic peptide assay in diagnosis of heart failure: cohort study in representative and high risk community populations.

Abstract Objective: To investigate the performance of a novel assay for N-terminal pro-brain natriuretic peptide (NT-proBNP) in diagnosing heart failure in various randomly selected general and high risk community populations. Design: Community cohort study (substudy of the echocardiographic heart of England screening study). Setting: Four randomly selected general practices in the West Midlands of England. Participants: 591 randomly sampled patients over the age of 45, stratified for age and socioeconomic status and falling into four cohorts (general population, patients with an existing clinical label of heart failure, patients prescribed diuretics, and patients deemed at high risk of heart failure). Main outcome measure: Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and area under receiver operating characteristic curve for NT-proBNP assay in the diagnosis of heart failure. Results: For NT-proBNP in the diagnosis of heart failure in the general population (population screen), a level of >36 pmol/l had a sensitivity of 100%, a specificity of 70%, a positive predictive value of 7%, a negative predictive value of 100%, and an area under the receiver operating characteristic curve of 0.92 (95% confidence interval 0.82 to 1.0). Similar negative predictive values were found for patients from the three other populations screened. Conclusions: This NT-proBNP assay seems to have value in the diagnosis of heart failure in the community. High negative predictive values indicate that the assays chief use would be to rule out heart failure in patients with suspected heart failure with normal concentrations of NT-proBNP. Positive results may identify patients who need cardiac imaging.

ABC of heart failure: History and epidemiology

Heart failure is the end stage of all diseases of the heart and is a major cause of morbidity and mortality. It is estimated to account for about 5% of admissions to hospital medical wards, with over 100 000 annual admissions in the United Kingdom. “The very essence of cardiovascular practice is the early detection of heart failure” Sir Thomas Lewis, 1933 #### Some definitions of heart failure “A condition in which the heart fails to discharge its contents adequately” (Thomas Lewis, 1933) “A state in which the heart fails to maintain an adequate circulation for the needs of the body despite a satisfactory filling pressure” (Paul Wood, 1950) “A pathophysiological state in which an abnormality of cardiac function is responsible for the failure of the heart to pump blood at a rate commensurate with the requirements of the metabolising tissues” (E Braunwald, 1980) “Heart failure is the state of any heart disease in which, despite adequate ventricular filling, the hearts output is decreased or in which the heart is unable to pump blood at a rate adequate for satisfying the requirements of the tissues with function parameters remaining within normal limits” (H Denolin, H Kuhn, H P Krayenbuehl, F Loogen, A Reale, 1983) “A clinical syndrome caused by an abnormality of the heart and recognised by a characteristic pattern of haemodynamic, renal, neural and hormonal responses” (Philip Poole-Wilson, 1985) “[A] syndrome … which arises when the heart is chronically unable to maintain an appropriate blood pressure without support” (Peter Harris, 1987) “A syndrome in which cardiac dysfunction is associated with reduced exercise tolerance, a high incidence of ventricular arrhythmias and shortened life expectancy” (Jay Cohn, 1988) “Abnormal function of the heart causing a limitation of exercise capacity” or “ventricular dysfunction with symptoms” (anonymous and pragmatic) “Symptoms of heart failure, objective evidence of cardiac dysfunction and …

Prevalence of atrial fibrillation in the general population and in high-risk groups: the ECHOES study

AIMS To establish the prevalence of atrial fibrillation (AF) in the general population in the UK, and in those with risk factors. METHODS AND RESULTS The prevalence of AF on electrocardiography was established in prospectively selected groups: 3960 randomly selected from the population, aged 45+; 782 with a previous diagnosis of heart failure; and 1062 with a record of myocardial infarction, hypertension, angina, or diabetes. Patients were also assessed clinically and with echocardiography. Mortality was tracked for 8 years. Atrial fibrillation was found in 78 of the random population sample (2.0%). Prevalence was 1.6% in women and 2.4% in men, rising with age from 0.2% in those aged 45-54 to 8.0% in those aged 75 and older. Half of all cases were in patients aged 75 and older. Only 23 of the 78 (29.5%) of those in AF took warfarin. Of the 782 patients, 175 (22.4%) with a diagnosis of heart failure were in AF, with normal left ventricular function in 95 (54.3%) of these. Atrial fibrillation was found in 14 of the 244 (5.7%) of those with a history of myocardial infarction, 15 of the 388 (3.9%) of those with hypertension, 15 of the 321 (4.7%) of those with angina, and 11 of the 208 (5.3%) of diabetics. Adjusting for age and sex, mortality was 1.57 times higher for those in AF. CONCLUSION Atrial fibrillation is common in the elderly and those with clinical risk factors. Screening these groups would identify many with AF. Use of anticoagulation was low at the time of the initial assessments in the late 1990s; practice may have changed recently.

A randomized trial of the addition of home‐based exercise to specialist heart failure nurse care: the Birmingham Rehabilitation Uptake Maximisation study for patients with Congestive Heart Failure (BRUM‐CHF) study

Supervised exercise can benefit selected patients with heart failure, however the effectiveness of home‐based exercise remains uncertain. We aimed to assess the effectiveness of a home‐based exercise programme in addition to specialist heart failure nurse care.

Reliability of N-terminal proBNP assay in diagnosis of left ventricular systolic dysfunction within representative and high risk populations

Objective: To determine the performance of a new NT-proBNP assay in comparison with brain natriuretic peptide (BNP) in identifying left ventricular systolic dysfunction (LVSD) in randomly selected community populations. Methods: Blood samples were taken prospectively in the community from 591 randomly sampled individuals over the age of 45 years, stratified for age and socioeconomic status and divided into four cohorts (general population; clinically diagnosed heart failure; patients on diuretics; and patients deemed at high risk of heart failure). Definite heart failure (left ventricular ejection fraction (LVEF) < 40%) was identified in 33 people. Samples were handled as though in routine clinical practice. The laboratories undertaking the assays were blinded. Results: Using NT-proBNP to diagnose LVEF < 40% in the general population, a level of > 40 pmol/l had 80% sensitivity, 73% specificity, 5% positive predictive value (PPV), 100% negative predictive value (NPV), and an area under the receiver-operator characteristic curve (AUC) of 76% (95% confidence interval (CI) 46% to 100%). For BNP to diagnose LVSD, a cut off level of > 33 pmol/l had 80% sensitivity, 88% specificity, 10% PPV, 100% NPV, and AUC of 88% (95% CI 75% to 100%). Similar NPVs were found for patients randomly screened from the three other populations. Conclusions: Both NT-proBNP and BNP have value in diagnosing LVSD in a community setting, with similar sensitivities and specificities. Using a high cut off for positivity will confirm the diagnosis of LVSD but will miss cases. At lower cut off values, positive results will require cardiac imaging to confirm LVSD.

Prevalence of left ventricular systolic dysfunction and heart failure in high risk patients: community based epidemiological study

abstract Objectives: To determine the prevalence of left ventricular systolic dysfunction, and of heart failure due to different causes, in patients with risk factors for these conditions. Design: Epidemiological study, including detailed clinical assessment, electrocardiography, and echocardiography. Setting: 16 English general practices, representative for socioeconomic status and practice type. Participants: 1062 patients (66% response rate) with previous myocardial infarction, angina, hypertension, or diabetes. Main outcome measures: Prevalence of systolic dysfunction, both with and without symptoms, and of heart failure, in groups of patients with each of the risk factors. Results: Definite systolic dysfunction (ejection fraction <40%) was found in 54/244 (22.1%, 95% confidence interval 17.1% to 27.9%) patients with previous myocardial infarction, 26/321 (8.1%, 5.4% to 11.6%) with angina, 7/388 (1.8%, 0.7% to 3.7%) with hypertension, and 12/208 (5.8%, 3.0% to 9.9%) with diabetes. In each group, approximately half of these patients had symptoms of dyspnoea, and therefore had heart failure. Overall rates of heart failure, defined as symptoms of dyspnoea plus objective evidence of cardiac dysfunction (systolic dysfunction, atrial fibrillation, or clinically significant valve disease) were 16.0% (11.6% to 21.2%) in patients with previous myocardial infarction, 8.4% (5.6% to 12.0%) in those with angina, 2.8% (1.4% to 5.0%) in those with hypertension, and 7.7% (4.5% to 12.2%) in those with diabetes. Conclusion: Many people with ischaemic heart disease or diabetes have systolic dysfunction or heart failure. The data support the need for trials of targeted echocardiographic screening, in view of the major benefits of modern treatment. In contrast, patients with uncomplicated hypertension have similar rates to the general population.

Prevalence of Heart Failure and Atrial Fibrillation in Minority Ethnic Subjects: The Ethnic-Echocardiographic Heart of England Screening Study (E-ECHOES)

Background Limited data exists on the prevalence of heart failure amongst minority groups in the UK. To document the community prevalence and severity of left ventricular systolic dysfunction, heart failure, and atrial fibrillation, amongst the South Asian and Black African -Caribbean groups in the UK. Methods and Results We conducted a cross-sectional study recruiting from September 2006 to July 2009 from 20 primary care centres in Birmingham, UK. 10,902 eligible subjects invited, 5,408 participated (49.6%) and 5,354 had complete data (49.1%). Subjects had median age 58.2 years (interquartile range 51.0 to 70.0), and 2544 (47.5%) were male. Of these, 1933 (36.3%) had BMI>30 kg/m2, 1,563 (29.2%) had diabetes, 2676 (50.0%) had hypertension, 307 (5.7%) had a history of myocardial infarction, and 104 (1.9%) had history of arrhythmia. Overall, 59 (1.1%) had an Ejection Fraction<40%, and of these 40 (0.75%) were NYHA class ≥2; 51 subjects (0.95%) had atrial fibrillation. Of the remaining 19 patients with an EF<40%, only 4 patients were treated with furosemide. A further 54 subjects had heart failure with preserved ejection fraction. Conclusions This is the largest study of the prevalence of left ventricular systolic dysfunction, heart failure and atrial fibrillation in under-researched minority communities in the UK. The prevalence of heart failure in these minority communities appears comparable to that of the general population but less than anticipated given the high rates of cardiovascular disease in these groups. Heart failure continues to be a major cause of morbidity in all ethnic groups and preventive strategies need to be identified and implemented.

Left ventricular ejection fraction: are the revised cut-off points for defining systolic dysfunction sufficiently evidence based?

The recent guidelines from the American Society of Echocardiography and European Society of Echocardiography have defined an abnormal ejection fraction (EF) of the left ventricle, as one that is <55%.1 Owing to the fact that it is a continuous biological variable, there is inevitable debate over what constitutes mild, moderate and severe left ventricular (LV) dysfunction across the ranges of EF. Up to now, the lower limit of normal in clinical practice has usually been set at 40%.2 Despite the recent guidelines,1 there has been little debate or evidence to suggest altering the lower limit of normality to include patients with EFs of 50–54%. These guidelines therefore represent a step change in the definition of (echocardiographic) LV systolic dysfunction and will include many more patients into the category of “impaired LV function” with EFs >50%. The main limitation of this approach is how best to define risk. The cut-off points suggested for a single parameter can vary broadly for the risk of death, myocardial infarction, congestive heart failure and atrial fibrillation. Also, much of the literature applies to specific populations (eg, after myocardial infarction, the elderly) and not to overall cardiovascular risk.1 The recommended new cut-off EF value of 54% is based on expert opinion, interpreting data from the limited number of studies that have reported that an EF <54% is associated with moderate adverse outcomes.1 For example, Roman et al followed up 486 patients undergoing echocardiography to determine the prevalence of carotid atherosclerosis and to examine its relationship to LV hypertrophy.3 Two hundred and seventy-seven subjects were normotensive and 209 subjects had untreated hypertension, and all were asymptomatic with no overt manifestations of cerebrovascular disease. The investigators found that 392 patients were essentially without any evidence of carotid plaques and 366 patients had …

Home-based exercise rehabilitation in addition to specialist heart failure nurse care: design, rationale and recruitment to the Birmingham Rehabilitation Uptake Maximisation study for patients with congestive heart failure (BRUM-CHF): a randomised controlled trial

BackgroundExercise has been shown to be beneficial for selected patients with heart failure, but questions remain over its effectiveness, cost-effectiveness and uptake in a real world setting. This paper describes the design, rationale and recruitment for a randomised controlled trial that will explore the effectiveness and uptake of a predominantly home-based exercise rehabilitation programme, as well as its cost-effectiveness and patient acceptability.Methods/designRandomised controlled trial comparing specialist heart failure nurse care plus a nurse-led predominantly home-based exercise intervention against specialist heart failure nurse care alone in a multiethnic city population, served by two NHS Trusts and one primary care setting, in the United Kingdom.169 English speaking patients with stable heart failure, defined as systolic impairment (ejection fraction ≤ 40%). with one or more hospital admissions with clinical heart failure or New York Heart Association (NYHA) II/III within previous 24-months were recruited.Main outcome measures at 1 year: Minnesota Living with Heart Failure Questionnaire, incremental shuttle walk test, death or admission with heart failure or myocardial infarction, health care utilisation and costs. Interviews with purposive samples of patients to gain qualitative information about acceptability and adherence to exercise, views about their treatment, self-management of their heart failure and reasons why some patients declined to participate.The records of 1639 patients managed by specialist heart failure services were screened, of which 997 (61%) were ineligible, due to ejection fraction>40%, current NYHA IV, no admission or NYHA II or more within the previous 2 years, or serious co-morbidities preventing physical activity. 642 patients were contacted: 289 (45%) declined to participate, 183 (39%) had an exclusion criterion and 169 (26%) agreed to randomisation.DiscussionDue to safety considerations for home-exercise less than half of patients treated by specialist heart failure services were eligible for the study. Many patients had co-morbidities preventing exercise and others had concerns about undertaking an exercise programme.