Chronic heart failure (CHF) is a clinical syndrome involving reduced cardiac output because of impaired cardiac contraction. Typical clinical symptoms of CHF include shortness of breath, fatigue and ankle swelling.
CHF prevalence is 1-2%, rising to 10% in those over 70 years old.
Stroke volume requires:
As a result, cardiac output (CO) can be reduced by any of the following factors (potentially causing CHF):
Cardiac output (CO) = Heart rate (HR) x Stroke volume (SV)
The most common causes of heart failure in the UK are coronary heart disease (myocardial infarction), atrial fibrillation, valvular heart disease and hypertension.
Other causes of heart failure include:
High-output cardiac failure occurs in states where demand exceeds normal cardiac output such as pregnancy, anaemia and sepsis.
Patients with CHF often present with symptoms that have gradually worsened over months to years.
Typical symptoms of CHF include:
When taking a history for suspected heart failure (CHF), important areas to consider include any pre-syncope or syncope and reduced appetite. Additionally, it is important to gather information regarding the patient's past medical history, family history, medications they are taking, and any social risk factors such as smoking, excess alcohol intake, and recreational drug use.
On cardiovascular examination of a suspected CHF patient, clinical findings may include:
On respiratory examination of a suspected CHF patient, clinical findings may include:
On abdominal examination of a suspected CHF patient, clinical findings may include:
NICE recommends performing certain investigations after history taking and clinical examination for suspected heart failure.
Relevant bedside investigations include:
ECG findings associated with heart failure include:
Relevant laboratory investigations include:
The investigation of chronic heart failure (CHF) should begin with a range of blood tests, including:
Screening for cardiomyopathy includes the following blood tests:
N-terminal pro-B-type natriuretic peptide (NT-proBNP) should be measured in all patients presenting with symptoms and clinical signs of heart failure to inform the type and urgency of further investigations such as echocardiography:
Other conditions in which NT-proBNP may be raised include left ventricular hypertrophy, tachycardia, liver cirrhosis, diabetes and acute or chronic renal disease.
All patients with suspected chronic heart failure should undergo transthoracic echocardiography, with the urgency determined by their NT-proBNP level.
Typical chest X-ray findings associated with CHF include alveolar oedema, kerley B lines, cardiomegaly, dilated upper lobe vessels and effusions.
Cardiac MRI is the gold standard investigation for assessing ventricular mass, volume and wall motion. It can be used with contrast to identify infiltration, inflammation or scarring. It is typically used when echocardiography has provided inadequate views.
Chronic heart failure (CHF) is a condition in which the heart is unable to pump enough blood throughout the body. It can be classified structurally based on left ventricular ejection fraction (LVEF). LVEF measures the percentage of blood that enters and is subsequently pumped out of the left ventricle. It usually is measured with transthoracic echocardiography, but can also be done through MRI, nuclear medicine scans, and transoesophageal echocardiography.
The New York Heart Association's (NYHA) classification system relies on patient symptoms and level of function: Class I (no symptoms during physical activity), Class II (slight limitation of physical activity by symptoms), Class III (less than ordinary activity leads to symptoms), Class IV (inability to carry out any activity without symptoms).
CHF management focuses on improving cardiac function, quality of life, preventing hospitalization, and reducing mortality.
Lifestyle management includes: fluid and salt restriction, regular exercise, smoking cessation, and reduced alcohol intake.
Everyone with CHF should be offered vaccinations for influenza and pneumococcal disease.
A medication review should be done to identify any medications that can be harmful to those with heart failure, such as calcium channel blockers, tricyclic antidepressants, lithium, NSAIDs, COX-2 inhibitors, corticosteroids, and QT-prolonging medications.
Patients with CHF need to be monitored for functional capacity, fluid status, cardiac rhythm, cognitive status, nutritional status, and renal function. The frequency of monitoring depends on clinical condition.
If heart failure is caused by coronary artery disease, statins and aspirin may be prescribed for secondary prevention.
Oral anticoagulation is prescribed for patients with heart failure and atrial fibrillation (paroxysmal or permanent) due to the risk of stroke.
Pharmacological treatment is aimed at increasing cardiac output by optimizing preload and contractility while decreasing afterload.
The medications discussed below are aimed to target the pathological sympathetic responses and renin-angiotensin-aldosterone system (RAAS) activation that occurs in chronic heart failure (CHF).
Diuretics are prescribed to alleviate symptoms associated with fluid overload such as shortness of breath and peripheral oedema. They work by increasing sodium excretion via diuresis, which ultimately reduces cardiac afterload. Doses should be adjusted according to clinical response and renal function should be closely monitored.
All patients with CHF and reduced ejection fraction (LVEF ≤ 40%) should be prescribed an ACE inhibitor, unless contraindicated. ACE inhibitors have been proven to improve ventricular function and reduce mortality. Urine and electrolytes should be tested prior to treatment and after 1-2 weeks. Contraindications for ACE inhibitors include a history of angioedema, bilateral renal artery stenosis, hyperkalaemia (> 5 mmol/L), severe renal impairment (serum creatinine > 220 μmol/L) and severe aortic stenosis.
Beta-blockers (e.g. bisoprolol) should be prescribed to all patients suffering from symptomatic heart failure and reduced LVEF (≤40%) unless there are contraindications. Beta-blockers lower heart rate and myocardial oxygen demand and reduce RAAS activation. Blood pressure and heart rate should be monitored when doses are adjusted. Contraindications include asthma, 2nd or 3rd degree AV block, sick sinus syndrome and sinus bradycardia.
If a patient is unable to tolerate an ACE inhibitor (usually due to persistent cough) an ARB (e.g. candesartan) should be prescribed as an alternative. Patients must have normal serum potassium and adequate renal function to commence an ARB.
A low-dose aldosterone antagonist (e.g. spironolactone or eplerenone) should be prescribed if a patient experiences persistent symptoms of heart failure despite diuretics, ACE inhibitors and beta-blockers. MRAs antagonise aldosterone, increasing sodium excretion via diuresis, reducing cardiac afterload.
SGLT2 inhibitors (e.g. dapagliflozin) are used as add-on therapy for patients with a LVEF < 40%. Dapagliflozin is known to reduce the risk of cardiovascular events and hospital admission, regardless of the patient's glycaemic control.
Ivabradine inhibits the sinoatrial node, decreasing heart rate of patients in sinus rhythm and increasing stroke volume while preserving myocardial contractility. It has been shown to reduce cardiovascular death or hospitalisation for heart failure by 18%.
ARNIs increase BNP levels by blocking the enzyme neprilysin, which breaks down BNP. An increase in BNP triggers natriuresis/diuresis, thus reducing cardiac afterload.
Chronic heart failure (CHF) is a clinical syndrome resulting in reduced cardiac output due to reduced cardiac contraction. Common causes in the UK are coronary heart disease and hypertension. Symptoms include shortness of breath, fatigue and ankle swelling.
Investigations required for diagnosis include ECG, NT-proBNP and echocardiography.
Management of CHF involves a combination of lifestyle modification, pharmacological therapies and, in some cases, surgical intervention. A visual summary of pharmacological management is shown in Figure 2.
If heart failure is caused or worsened by other conditions, these should be managed appropriately:
Complications of CHF include:
The prognosis of CHF is poor overall, with approximately 50% of people with heart failure dying within five years of diagnosis.
