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March 2009 Clinical Pharmacist Heart failure accounts for at least one in 20 admissions to hospitals in the UK. It occurs most commonly in older people, with prevalence rates doubling for every decade of ageing Heart failure clinical features and diagnosis By Mojgan Sani, DPharm, MRPharmS eart failure is a major and growing health concern in the UK and is still associated with a high morbidity and mortality despite progress in its diagnosis and treatment. The National Service Framework for coronary heart disease (CHD) sets national standards of care relating to CHD, including providing better care for patients with heart failure. The National Institute for Health and Clinical Excellence and the Scottish Intercollegiate Guidelines Network have both issued guidelines for the management of people with chronic heart failure. H SUMMARY Heart failure is a complex syndrome resulting from structural or functional cardiac disorder. The syndrome is characterised by symptoms and signs of breathlessness, fatigue and fluid retention. Many risk factors cause heart failure, including coronary artery disease, hypertension, congenital heart disease, arrhythmias, alcohol and some medicines. Heart failure is a major and growing health problem among older people. Diagnostic and therapeutic options have advanced over the years, together with national and international standards and guidelines focused on improving the care of patients with heart failure. Definition Many definitions of heart failure have been documented over the past 50 years. These definitions tend to include the features of heart failure such as haemodynamics, oxygen consumption, or exercise capacity. Guidelines from the European Society of Cardiology (2008)1 set out the defining features of heart failure (shown in Box 1, p115). Heart failure can also been defined as: Krishnacreations | Dreamstime.com ● New-onset ● Transient ● Chronic New-onset heart failure refers to the first presentation of the disease. Transient heart failure refers to symptomatic heart failure over a limited period of time after which patients recover from the syndrome. Examples include patients with mild myocarditis, post myocardial infarction (heart failure resolved by diuretics administered in a coronary care unit), or heart failure due to ischaemia (resolved by coronary revascularisation). Chronic heart failure is the most common type that requires hospital admission. Treatment is based on patients’ clinical presentation (see accompanying article, p120). Classification Two classifications of the severity of heart failure are described in the ESC guidelines, as shown in Box 2 (p115).1 The New York Heart Association functional classification is based on symptoms and exercise capacity and is Mojgan Sani is head of cardiac pharmacy at the Regional Wessex Cardiac Centre. Dr Sani was also a member of the guideline development group for the National Institute for Health and Clinical Excellence’s 2003 clinical guideline on heart failure. E: [email protected] 113 CLINICAL FOCUS For personal use only. Not to be reproduced without permission of the editor ([email protected]) Vol 1 Vol 1 Epidemiology Lack of universal agreement on the definition of heart failure over the years has made epidemiological studies difficult. The Framingham heart study, which had a cohort of 5,209 subjects, has been followed up biennially since 1948. This dataset has been used to obtain some information on the incidence and prevalence of heart failure, defined using clinical and radiographic criteria.2 The Framingham Box 1: Definition of heart failure Heart failure is a clinical syndrome in which patients have the following features: ● Symptoms such as breathlessness at rest or with Clinical Pharmacist study reported that the age-adjusted prevalence of heart failure was similar for men and women during the 1980s. This prevalence increased significantly with increasing age (doubling the rate of prevalence with each decade of ageing). Heart failure accounts for at least 5% of admissions to hospitals in the UK.3,4 Hospital admission for heart failure accounts for approximately 1% of the total healthcare expenditure in the UK. Epidemiological studies have shown that the financial burden of heart failure on health services is increasing.3 Hospital admissions and GP consultations occur frequently following diagnosis and readmission rates among the elderly range from 29% to 47% within three to six months of the initial hospital discharge.3,4 The prevalence of heart failure is 2–3%, rising sharply at around 75 years of age.1 In the younger population, heart failure is more common in men, with the cause attributed to coronary heart disease. Prevalence is similar between older men and women. Although some patients live for many years, overall 50% of patients will have died four years after diagnosis. exercise, fatigue, tiredness, ankle swelling ● Signs such as tachycardia, tachypnoea, Causes pulmonary rales, pleural effusion, raised jugular venous pressure, peripheral oedema, hepatomegaly ● Objective evidence of structural or functional abnormality of the heart at rest — cardiomegaly, third heart sound, cardiac murmurs, abnormality on echocardiogram, raised natriuretic peptide concentration ESC guidelines state that the most common reasons for functional deterioration of the heart are damage or loss of heart muscle, acute or chronic ischaemia, increased vascular resistance with hypertension, or the development of a tachyarrhythmia such as atrial fibrillation. Causes of heart failure therefore include: Box 2: Heart failure classification ACC/AHA STAGES OF HEART FAILURE NYHA FUNCTIONAL CLASSIFICATION (STAGES OF HEART FAILURE BASED ON STRUCTURE AND DAMAGE TO HEART MUSCLE) (SEVERITY BASED ON SYMPTOMS AND PHYSICAL ACTIVITY) Stage A At high risk for developing heart failure. No identified structural or functional abnormality; no signs or symptoms Class I No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation or dyspnoea Stage B Developed structural heart disease that is strongly associated with the development of heart failure, but without signs and symptoms Class II Slight limitation of physical activity. Comfortable at rest but ordinary physical activity results in fatigue, palpitation or dyspnoea Stage C Class III Symptomatic heart failure associated Marked limitation of physical activity. with underlying structural heart disease Comfortable at rest but less than ordinary physical activity results in fatigue, palpitation or dyspnoea Stage D Advanced structural heart disease and marked symptoms of heart failure at rest despite maximal medical therapy Class IV Unable to carry out any physical activity without discomfort. Symptoms at rest. If any physical activity is undertaken discomfort is increased ACC/AHA = American College of Cardiology and American Heart Association NYHA = New York Heart Association ● Coronary artery disease (myocardial infarction, ischaemia) ● Hypertension ● Cardiomyopathy ● Congenital heart disease ● Arrhythmias (tachycardia and bradycardia) ● Alcohol ● Medicines (calcium antagonists, antiarrhythmics, cytotoxic drugs) Pathophysiology Heart failure is a multisystem disorder associated with systolic and diastolic dysfunction of the myocardial tissue. It is characterised by abnormalities of cardiac, skeletal muscle and renal function; stimulation of the sympathetic nervous system; and a complex pattern of neurohormonal changes. Myocardial systolic dysfunction Myocardial systolic dysfunction is described by impairment of left ventricular function, which leads to a fall in cardiac output. This in turn leads to activation of neurohormonal compensatory mechanisms aiming to improve the mechanical capacity of the heart, as shown in Figure 1 (p116). It has been estimated that 30–40% of patients with heart failure have normal ventricular systolic contraction.5 Myocardial diastolic dysfunction Myocardial diastolic dysfunction occurs because myocardial relaxation is compromised, causing stiffness in the ventricular wall and impairment of diastolic ventricular filling.5 115 CLINICAL FOCUS routinely used in clinical trials. The American College of Cardiology and American Heart Association classification describes stages of heart failure based on structural changes and symptoms. March 2009 CLINICAL FOCUS 116 Clinical Pharmacist March 2009 Vol 1 Figure 1: Neurohormonal mechanism and compensatory mechanism in heart failure Left ventricular dysfunction Heart failure value for heart failure, a completely normal ECG would mean that systolic dysfunction is unlikely. Common ECG abnormalities in patients with heart failure can include: sinus tachycardia; sinus bradycardia; atrial tachycardia, flutter or fibrillation; ventricular arrhythmias; ischaemia; left ventricular hypertrophy; and atrioventricular block. Reduced stroke volume and cardiac output Chest X-ray Chest X-ray is an important diagnostic tool Neurohormonal response Activation of sympathetic nervous system Activation of renin-angiotensinaldosterone system Vasoconstriction (increased catecholamines) Vasoconstriction (increased angiotensin) Raised heart rate and contractility Increased blood volume, salt and water retention (aldosterone) Ventricular wall dilatation (remodelling) and further heart failure Symptoms The most common symptoms of chronic heart failure include dyspnoea, fatigue, lethargy and oedema. Breathlessness on exertion is particularly common in heart failure, particularly in patients with comorbid pulmonary disease. Orthopnoea is thought to be a more specific symptom, and paroxysmal nocturnal dyspnoea has a greater predictive value for heart failure as it results from increased left ventricular filling pressure. Fatigue and lethargy are related to skeletal muscle abnormalities and impaired muscle blood flow. Swelling of ankles and feet (oedema) is also commonly seen when patients present with heart failure. Although there seems to be a poor relationship between symptoms and the severity of cardiac dysfunction, symptoms tend to correlate well with prognosis. Symptom control can be used effectively for monitoring the effects of therapy. for patients with suspected heart failure and it can also be used to monitor the response to therapy. Chest X-ray may show cardiac enlargement (including cardiomegaly), pulmonary venous congestion, pleural effusion, and pulmonary infection or infiltration. Natriuretic peptides The heart secretes natriuretic peptides as a homeostatic signal to maintain stable blood pressure and prevent excess salt and water retention. Atrial natriuretic peptide (ANP) has been identified in the atrial myocardium. B-type natriuretic peptide (BNP) is primarily secreted by the ventricles in the heart as a response to ventricular stretching or wall tension.6 BNP levels can be used to assess cardiac function, to help diagnose heart failure, including diastolic dysfunction, and to monitor the success of treatment. However, the use of BNP testing has been controversial because of its cost and also because BNP levels can be increased in pulmonary or renal diseases. Nevertheless, BNP concentrations are thought to correlate well with severity of heart failure and prognosis. Troponins Troponin I or T levels are mainly used to determine myocyte necrosis in acute coronary syndrome and hence can identify potential candidates for coronary revascularisation. Troponin levels are also raised in acute myocarditis and in severe heart failure or during a period of acute fluid overload (ie, decompensation, for example due to ischaemia or sepsis). The combination of increased troponin levels and an increased BNP level is a strong marker for the presence of heart failure. Echocardiography Echocardiography is the most useful non-invasive tool for the assessment of left ventricular dysfunction and, ideally, should be used for all patients with suspected heart failure. Diagnosis There are several diagnostic techniques that can be used to determine heart failure. NICE’s diagnostic algorithm is reproduced in Figure 2 (p119). Clinical examination The symptoms and signs of heart failure are crucially important for early identification of heart failure. The ESC guidelines recommend the clinical assessments described in Box 3, including observation, palpation and auscultation. Electrocardiogram An electrocardiogram (ECG) is taken routinely for all patients with suspected heart failure. Although an abnormal ECG has little predictive Box 3: Clinical examination Appearance Alertness, nutritional state, weight Pulse Rate, rhythm and character Blood pressure Systolic, diastolic and pulse pressure Fluid overload Jugular venous pressure, peripheral oedema (ankles and sacrum), hepatomegaly, ascites Lungs Respiratory rate, rales, pleural effusion Heart Apex displacement, gallop rhythm, third heart sound and murmurs Vol 1 Prognosis Cardiac catheterisation Cardiac catheterisation is not 3 used routinely for the diagnosis or management of heart failure. It is considered useful for heart failure patients with a history of angina or ischaemic left ventricular dysfunction. It may also be used for patients with refractory heart failure of unknown cause. 4 Pulmonary function testing Spirometry is useful 7 for excluding respiratory causes of breathlessness and to evaluate the severity of concomitant pulmonary disease. 8 Clinical Pharmacist Determining an individual heart failure patient’s prognosis is difficult, with many factors complicating the picture. These factors include: advanced age; ischaemia; arrhythmias; marked elevation of BNP; low LVEF; and presence of other diseases such as diabetes, renal dysfunction, anaemia, chronic obstructive pulmonary disease and depression. References 1 2 5 6 Task force for diagnosis and treatment of acute and chronic heart failure 2008 of the European Society of Cardiology. ESC guidelines for the diagnosis and treatment of chronic heart failure 2008. European Heart Journal 2008;29:2388–442. Ho KK, Pinsky JL, Kannel WB, et al. The epidemiology of heart failure: Framingham study. Journal of the American College of Cardiology 1993;22:6–13A. Cowie MR, Mosterd A, Wood DA, et al. The epidemiology of heart failure. European Heart Journal 1997;18:208–25. Cowie MR, Wood DA, Coats AJS, et al. Incidence and aetiology of heart failure: a population-based study. European Heart Journal 1999;20:421–8. Grossman W. Diastolic dysfunction in congestive heart failure. New England Journal of Medicine 1991;325:1557–64. Yasue H, Yoshimura M, Surhida H, et al. Localisation and mechanism of secretion of B-type natriuretic peptide in comparison with those of Atype natriuretic peptide in normal subjects and patients with heart failure. Circulation 1994;90:195–203. Cheesman MG, Leech G, Chambers J, et al. Central role of echocardiography in the diagnosis and assessment of heart failure. Heart 1998;80(s1):S1–5. National Institute for Health and Clinical Excellence. Management of chronic heart failure in adults in primary and secondary care. www.nice.org.uk (accessed 17 February 2009). Figure 2: Diagnostic algorithm for heart failure This algorithm, which summarises recommendations for the diagnosis of heart failure, forms part of a clinical guideline published by the National Institute for Health and Clinical Excellence in 2003.8 The guideline is being reviewed by NICE and a partial update is expected in 2010 KEY BNP = B-type natriuretic peptide ECG = Electrocardiogram FBC = Full blood count LFTs = Liver function tests TFTs = Thyroid function tests U&Es = Urea and electrolytes Suspected heart failure ? How can you fit diploma tutoring into your busy workload (history, signs and symptoms) Seek to exclude heart failure through ● 12-lead echocardiogram ● and/or natriuretic peptide (eg, BNP) where available Other recommended tests to exclude other conditions ● Chest X-ray ● Blood tests: U&Es, creatinine, FBC, TFTs, LFTs, glucose and lipids ● Urinalysis and peak flow/spirometry CAREER DEVELOPMENT Both normal Heart failure unlikely, consider alternative diagnosis No abnormality detected Heart failure unlikely, but if diagnostic doubt persists consider diastolic dysfunction and consider referral for specialist assessment One of more abnormal Imaging by echocardiography Abnormal Assess heart failure severity, cause, precipitating and exacerbating factors and type of cardiac dysfunction. Correctable causes must be identified. Consider referral (p141) 119 CLINICAL FOCUS Echocardiography allows a quantitative measurement of the left ventricular ejection fraction (LVEF normal >45%), which in turn is well correlated with the outcome and survival of patients with heart failure.7 Advances in echocardiography using contrast agents have allowed for observation of left ventricular walls in more detail. Common echocardiographic abnormalities observed in heart failure include: reduced left ventricular ejection fraction, increased left atrial size, left ventricular thickness, and valvular stenosis or regurgitation. Greater availability of echocardiography services for heart failure patients in primary care has the potential to improve patient’s prognosis through speedier diagnosis. March 2009