Chronic heart failure is a high-yield exam topic because its drug treatment has been transformed into the "four pillars," and because the diagnostic pathway hinges on a single blood test. This guide covers chronic heart failure with reduced ejection fraction as examiners frame them, to the current NICE standard (NG106, updated 2025). Follow current guidance and local protocols in practice; this reflects guidance as of mid-2026.
What heart failure is
Heart failure is a clinical syndrome in which the heart cannot maintain an adequate cardiac output for the body's needs, or can do so only at the cost of raised filling pressures. It is classified by the left ventricular ejection fraction: heart failure with reduced ejection fraction (HFrEF, an ejection fraction of 40% or below), with mildly reduced ejection fraction (41 to 49%), and with preserved ejection fraction (50% or above). The drug treatment that follows differs markedly between these, and the exam focus is HFrEF. Heart failure can also be described as left-sided (causing pulmonary congestion and breathlessness), right-sided (causing peripheral oedema and a raised jugular venous pressure), or congestive when both coexist — a framing examiners use to link symptoms to mechanism.
Presentation
The cardinal features are exertional breathlessness, fatigue, and fluid retention — ankle swelling, and orthopnoea or paroxysmal nocturnal dyspnoea. Signs include a raised jugular venous pressure, bibasal crepitations, a displaced apex beat, peripheral oedema and a third heart sound. The commonest cause in the UK is ischaemic heart disease, followed by hypertension and valvular disease. Acute decompensation presents with acute breathlessness and pulmonary oedema, sometimes with pink frothy sputum, and is a medical emergency managed with oxygen and intravenous diuretics, with the patient sat up and closely monitored. A precipitant should always be sought when stable heart failure decompensates: a missed or stopped medication, excess salt or fluid, an arrhythmia such as new atrial fibrillation, infection, an acute coronary event, or anaemia.
Diagnosis
The pathway starts with a blood test: measure NT-proBNP. A high level prompts urgent referral and echocardiography — the higher the level, the more urgent, with very high levels warranting specialist assessment and an echo within two weeks. Echocardiography confirms the diagnosis, measures the ejection fraction and identifies the cause. A normal NT-proBNP makes heart failure unlikely. An ECG and bloods complete the work-up, and a chest X-ray may show cardiomegaly, congestion or effusions. NICE also recommends assessing iron status, as iron deficiency is common in heart failure and intravenous iron can improve symptoms.
Management: the four pillars
This is the highest-yield part of the topic. For HFrEF, NICE now recommends offering all four pillars of disease-modifying therapy, started early and titrated to the maximum tolerated dose:
- An ACE inhibitor (an ARB if not tolerated, or an angiotensin receptor-neprilysin inhibitor, ARNI, in defined situations).
- A beta-blocker licensed for heart failure (bisoprolol, carvedilol or nebivolol).
- A mineralocorticoid receptor antagonist (MRA) — spironolactone or eplerenone.
- An SGLT2 inhibitor — dapagliflozin or empagliflozin.
For a patient who remains symptomatic on the maximum tolerated dose of all four, NICE advises considering switching the ACE inhibitor to an ARNI. Crucially, a loop diuretic such as furosemide is used to relieve congestion and breathlessness but does not improve survival — it treats symptoms, while the four pillars treat the disease.
Specialist options include ivabradine (for those in sinus rhythm with a persistently high heart rate), hydralazine with a nitrate (of particular value in patients of African or Caribbean family origin), and digoxin, alongside device therapy — cardiac resynchronisation therapy or an implantable defibrillator — in selected patients. Certain calcium-channel blockers, namely verapamil and diltiazem, are avoided in HFrEF. Treatment of heart failure with preserved ejection fraction is more limited — diuretics for congestion, management of comorbidities such as hypertension and atrial fibrillation, and increasingly an SGLT2 inhibitor — since the four-pillar regimen is specific to the reduced-ejection-fraction group.
High-yield exam points and traps
- The four pillars of HFrEF treatment are an ACE inhibitor (or ARNI), a beta-blocker, an MRA and an SGLT2 inhibitor — all four, started early.
- Diuretics relieve symptoms but do not improve mortality — a frequent distinguishing question.
- NT-proBNP is the gateway test; the level sets the urgency of referral and echo. Levels are affected by other conditions — obesity can lower them, while atrial fibrillation and renal impairment raise them — so the result is read in context.
- Beta-blockers are disease-modifying in stable heart failure despite being negative inotropes — started low and titrated slowly, not during acute decompensation. They are introduced when the patient is stable and euvolaemic, with gradual up-titration, because abrupt increases can worsen heart failure transiently.
- SGLT2 inhibitors are now a core pillar, not an add-on, for HFrEF, and benefit patients whether or not they have diabetes.
- Avoid verapamil and diltiazem in HFrEF.
A few common questions
What are the four pillars of heart failure treatment? For HFrEF: an ACE inhibitor (or an ARNI), a beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor — all four, started early and titrated up.
Do diuretics improve survival in heart failure? No — loop diuretics relieve congestion and breathlessness but do not reduce mortality; the four pillars are the disease-modifying treatments. The diuretic dose is adjusted to the patient’s fluid status.
What blood test is used to diagnose heart failure? NT-proBNP; a raised level prompts referral and echocardiography, with the level determining how urgently, and a normal level makes heart failure unlikely.
Which beta-blockers are used in heart failure? Those licensed for heart failure — bisoprolol, carvedilol or nebivolol — started at a low dose and titrated slowly once the patient is stable.
What ejection fraction defines HFrEF? A left ventricular ejection fraction of 40% or below; 41 to 49% is mildly reduced and 50% or above is preserved. The drug treatment differs between these groups.
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