See also separate articles: Heart Failure Management, Cardiac Rehabilitation and Palliative Care of Heart Failure.

Heart failure is a clinical syndrome characterised by:

• Typical symptoms: breathlessness, fatigue, ankle swelling.
• Typical signs: tachycardia, tachypnoea, pulmonary rales, pleural effusion, raised jugular venous pressure (JVP), peripheral oedema, hepatomegaly.
• Objective evidence of a structural or functional abnormality of the heart at rest: cardiomegaly, third heart sound, cardiac murmurs, echocardiogram abnormalities, raised natriuretic peptide concentration.

The European Society of Cardiology's guidelines require that there be symptoms, signs and objective evidence present before a diagnosis of heart failure can be made.¹ Heart failure has a number of different aetiologies (see below under 'Aetiology') - always try to determine the cause. Heart failure should never be the only diagnosis, as it is a syndrome occurring as a result of other diagnostic entities.

Classification

Acute and chronic

Heart failure has traditionally been described as acute or chronic, but this can be confusing and should be used to describe time, rather than severity. New-onset (first presentation with acute or slow onset), transient (recurrent or episodic) and chronic (persistent whether stable, worsening or decompensated) heart failure may be a more useful classification.

Systolic and diastolic

Similarly, a distinction is frequently made between systolic and diastolic heart failure. This is somewhat arbitrary and many patients with heart failure have evidence of both. Left ventricular systolic dysfunction (LVSD) is usually defined as an LV ejection fraction <40% on echocardiography.
Some symptomatic patients have a normal ejection fraction and no obvious cause for increased myocardial demand. This condition has been variously termed diastolic heart failure, heart failure with preserved LV function, heart failure with a normal ejection fraction (HFNEF) or heart failure with preserved systolic function (HFPSF).²

High and low output

Certain medical conditions (see under 'Aetiology' below) increase demands on cardiac output, causing a clinical picture of heart failure and this is known as high-output cardiac failure. The primary abnormality is not the heart and the heart failure is reversible with treatment. Low-output failure is where cardiac output is inadequate to perfuse the body (i.e. ejection fraction <40%), or can only be adequate with high filling pressures.

Epidemiology

Europewide:¹

• Prevalence of asymptomatic ventricular dysfunction is approximately 4%.
• Prevalence of heart failure is between 2-4% in the general population, increasing significantly with age to between 10-20% in the over-75s.
• In younger age groups, heart failure is more common in men because of the earlier onset of ischaemic heart disease (IHD).
• Prevalence is increasing due to aging populations and improved survival after coronary events and secondary prevention.

A UK survey of heart failure management in general practice found an average prevalence of 8.3 per 1,000 population.³

Aetiology

Coronary heart disease and hypertension are the most common causes of heart failure in the UK. A general practice population will have about 47% of men with heart failure having coronary artery disease as the cause and 46% of women with heart failure having hypertension as the cause.³

• Valve heart disease - approximately 10% of cases:
  • Aortic stenosis can cause left ventricular hypertrophy (LVH) due to chronic excessive afterload.
  • Aortic or mitral regurgitation, atrial septal defect (ASD), ventricular septal defect (VSD) and tricuspid incompetence cause excessive preload.
• Heart failure secondary to myocardial disease:¹
  • Coronary heart disease (myocardial infarction (MI) and ischaemia, arrhythmias, e.g. atrial fibrillation (AF), heart block).
  • Hypertension (increased vascular resistance, often with LVH but preserved ejection fraction).
  • Cardiomyopathies.
  • Drugs, e.g. betablockers, calcium antagonists, anti-arrhythmics, cytotoxics.
  • Toxins, e.g. alcohol, cocaine, mercury, cobalt, arsenic.
  • Endocrine, e.g. diabetes, hypothyroidism, hyperthyroidism, Cushing's syndrome, adrenal insufficiency, excessive growth hormone, phaeochromocytoma.
  • Nutritional, e.g. deficiencies of thiamine, selenium, carnitine, and obesity, cachexia.
  • Infiltrative, e.g. sarcoidosis, amyloidosis, haemochromatosis, Löffler's eosinophilia, connective tissue disease.
  • Infective, e.g. Chagas' disease, HIV.
• High-output failure - this occurs when cardiac output is normal or increased in the face of much increased needs. It can occur with a normal heart, but even earlier if there is heart disease. Causes include:
  • Anaemia.
  • Pregnancy.
  • Hyperthyroidism.
  • Paget's disease of bone.
  • Arteriovenous malformations.
  • Beriberi.

Presentation

In general, the heart fails as a whole, but sometimes a disproportionate burden falls on one ventricle, and this influences the pattern of symptoms and signs. There is no symptom or sign that is both sensitive and specific for chronic heart failure.⁴

Symptoms

• Dyspnoea and fatigue (may limit exercise tolerance).
• Fluid retention (may cause pulmonary or peripheral oedema).
• Patients do not necessarily have both, and either may dominate at any one time. In addition, patients may be depressed or complain of drug-related side-effects.
• When there is left ventricular failure (LVF): dyspnoea, poor exercise tolerance, fatigue, orthopnoea, paroxysmal nocturnal dyspnoea (PND), nocturnal cough (± pink frothy sputum) or wheeze, nocturia, cold peripheries, weight loss and muscle wasting.
• Right ventricular failure (RVF): peripheral oedema (up to thighs, sacrum, abdominal wall), abdominal distension (ascites), nausea, anorexia, facial engorgement, pulsation in the neck and face (tricuspid regurgitation), epistaxis.

Signs

• The patient may look ill and exhausted, with tachypnoea, cool peripheries, peripheral ± central cyanosis.
• There may be a tachycardia at rest, low systolic blood pressure (BP), a displaced apex (LV dilatation) or RV heave (pulmonary hypertension), a narrow pulse pressure or pulsus alternans (alternating large and small pulse pressures)⁵ and a raised JVP.
• On auscultation there may be a gallop rhythm due to presence of S3 (see heart sounds) or murmurs of mitral or aortic valve disease; bilateral basal end-inspiratory crackles ± wheeze ('cardiac asthma'), pleural effusions, tender hepatomegaly - pulsatile in tricuspid regurgitation, with ascites and often extensive peripheral oedema.⁶
• The peak expiratory flow rate may be reduced but, if it is <150 litres/minute, suspect chronic obstructive pulmonary disease (COPD) or asthma.

Investigations

The National Institute for Health and Clinical Excellence (NICE) makes the pathway for diagnosis explicit after detailed history and examination:⁷

If there has been a previous MI

The patient should be referred for specialist assessment and Doppler echocardiography within 2 weeks. Echocardiography is the key test to provide a semi-objective assessment of cardiac function. It enables an assessment of:

• Overall LV systolic function.
• Diastolic function (necessary to diagnose HFPEF).
• LV wall thickness.
• Valvular disease.
• Estimation of pulmonary artery systolic pressure.

If an abnormality is found consistent with heart failure, the severity, aetiology, precipitating factors, type of cardiac dysfunction and treatable causes are assessed.
If there is no obvious abnormality, consider measuring serum natriuretic peptides (if not already done). If the levels are raised, there may be heart failure with a preserved ejection fraction or another diagnosis. If the levels are normal, the diagnosis is unlikely to be heart failure.

No previous MI

B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) are released into the blood when the myocardium is stressed. Measure serum natriuretic peptides:

• If levels are high (BNP ≥400 pg/ml), the patient should be referred for specialist assessment and Doppler echocardiography within 2 weeks - as before.
• If levels are raised (BNP ≥100-400 pg/ml), the referral and assessment may be made within 6 weeks.
• If the levels are normal (BNP ≤100 pg/ml), heart failure is unlikely and other diagnoses should be considered.

Very high levels of serum natriuretic peptides (≥400 pg/ml) carry a poor prognosis. Natriuretic peptide levels may also be elevated in other conditions such as chronic hypoxaemia, renal dysfunction, advanced age, liver cirrhosis and sepsis.
Assessing the aetiology may involve:

• Blood tests: FBC, U&E and creatinine, LFTs, glucose, fasting lipids, thyroid function tests; consider cardiac enzymes if an undiagnosed MI is possible in the last few days.
• 12-lead ECG: this may elucidate the cause of heart failure (e.g. sinus tachycardia or bradycardia, supraventricular tachycardia (SVT)/AF, Q waves suggesting previous MI; also look for ischaemic ST changes, bundle branch block, AF, left axis deviation, and ventricular hypertrophy). An abnormal ECG has little predictive value for heart failure but a normal ECG makes LVSD unlikely (negative predictive value of 98%).⁸ Consider 24-hour ECG to detect paroxysmal arrhythmias
• CXR - provides supportive evidence for heart failure and helps to exclude other potential causes of breathlessness. Typical findings in heart failure include:
  • Cardiomegaly (cardiothoracic ratio >50%).
  • Ventricular hypertrophy.
  • Prominent upper lobe veins (upper lobe diversion).
  • Peribronchial cuffing.
  • Diffuse interstitial or alveolar shadowing - classical perihilar 'bat's wings' or nodular (especially with pre-existing COPD).
  • Fluid in the fissures.
  • Pleural effusions.
  • Kerley B lines.
  Apart from pulmonary congestion, CXR findings are only predictive of heart failure where there are co-existing typical signs and symptoms.
• Urinalysis.
• Lung function tests (peak flow or spirometry).
• Cardiac magnetic resonance imaging - the gold standard for assessing ventricular volumes, mass and wall motion. It can be used with contrast to identify inflammation, infiltration and scarring of the myocardium. Its use is limited by availability and cost.
• Exercise testing, CT angiography or coronary angiography are not part of routine diagnosis of heart failure but may be considered where IHD is suspected.
• Radionuclide imaging may be helpful to assess global ventricular function when echocardiography is not possible.
• Endomyocardial biopsy is rarely needed.

Staging

Functional capacity may be assessed using a standardised exercise test such as the 6-minute walk test (which strongly and independently predicts morbidity and mortality in patients with LV dysfunction).⁹ Most patients do not show a linear deterioration, but may fluctuate even in the absence of treatment changes, and changes in treatment may make things better, or worse, in the absence of measurable changes in ventricular function.

The New York Heart Association's (NYHA) Classification of Heart Failure has provided a clinically useful, functional classification, outlined below:

Prognosis

• Prognosis is poor on the whole, with 5-year mortality varying from 26-75%.^10,11
• Heart failure accounts for at least 5% of medical hospital admissions in the UK and up to 16% of patients are back in hospital within 6 months of their first admission.
• When patients present with acute pulmonary oedema their prognosis is poorer; survival rates are predicted by severity. In those presenting with cardiogenic shock (hypotension with systolic BP <90 mm Hg, oliguria and low cardiac output), hospital mortality can be as high as 90%.

Document references

1. Guidelines for the diagnosis and treatment of acute and chronic heart failure, European Society of Cardiology (January 2008)
2. Sanderson JE; Heart failure with a normal ejection fraction. Heart. 2007 Feb;93(2):155-8. Epub 2005 Dec 30. [abstract]
3. Majeed A, Williams J, de Lusignan S, et al; Management of heart failure in primary care after implementation of the National Service Framework for Coronary Heart Disease: a cross-sectional study. Public Health. 2005 Feb;119(2):105-11. [abstract]
4. Management of Chronic Heart Failure, Scottish Intercollegiate Guidelines Network (SIGN), Feb 2007
5. McLaughlin DP; Images in clinical medicine. Pulsus alternans. N Engl J Med. 1999 Sep 23;341(13):955.
6. Watson RD, Gibbs CR, Lip GY; ABC of heart failure. Clinical features and complications. BMJ. 2000 Jan 22;320(7229):236-9.
7. Chronic heart failure, NICE Clinical Guideline (August 2010); Chronic heart failure: management of chronic heart failure in adults in primary and secondary care
8. Dargie HJ, McMurray JJ; Diagnosis and management of heart failure. BMJ. 1994 Jan 29;308(6924):321-8.
9. Bittner V, Weiner DH, Yusuf S, et al; Prediction of mortality and morbidity with a 6-minute walk test in patients with left ventricular dysfunction. SOLVD Investigators. JAMA. 1993 Oct 13;270(14):1702-7. [abstract]
10. Cowie MR, Mosterd A, Wood DA, et al; The epidemiology of heart failure. Eur Heart J. 1997 Feb;18(2):208-25.
11. Stewart S, MacIntyre K, Hole DJ, et al; More 'malignant' than cancer? Five-year survival following a first admission for heart failure. Eur J Heart Fail. 2001 Jun;3(3):315-22. [abstract]

Internet and further reading

• Chronic heart failure, NICE Clinical Guideline (August 2010); Chronic heart failure: management of chronic heart failure in adults in primary and secondary care
• Hunt SA, Abraham WT, Chin MH, et al; 2009 Focused update incorporated into the ACC/AHA 2005 Guidelines for the Diagnosis and Management of Heart Failure in Adults A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines Developed in Collaboration With the International Society for Heart and Lung Transplantation. J Am Coll Cardiol. 2009 Apr 14;53(15):e1-e90.
• The use of B-type natriuretic peptides (BNP and NT-proBNP) in the investigation of patients with suspected heart failure, NHS Quality Improvement Scotland (2005)
• Heart failure - chronic, Clinical Knowledge Summaries (November 2010)

Acknowledgements