About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Heart failure = clinical syndrome of breathlessness, fatigue, and fluid retention due to impaired cardiac output
- Classify by ejection fraction: HFrEF (≤40%), HFmrEF (41–49%), HFpEF (≥50%)
- First investigation: NT-proBNP (>400 pg/mL = suspected HF, >2000 = urgent referral within 2 weeks)
- HFrEF treatment pillars: ACE inhibitor + beta-blocker + MRA + SGLT2 inhibitor ("four pillars")
- All patients: offer cardiac rehabilitation, flu and pneumococcal vaccination
Overview
Heart failure is a complex clinical syndrome resulting from any structural or functional cardiac abnormality that impairs ventricular filling or ejection of blood. It is not a single disease but the final common pathway of multiple pathologies. The 2026 MLA content map identifies it as a high-priority condition. Classification now centres on left ventricular ejection fraction (LVEF): HFrEF (reduced, ≤40%), HFmrEF (mildly reduced, 41–49%), and HFpEF (preserved, ≥50%). This distinction is critical because evidence-based drug therapy is strongest for HFrEF.
Epidemiology
Approximately 920,000 people in the UK live with heart failure, with around 200,000 new diagnoses per year. Prevalence increases steeply with age — roughly 1–2% in the general population, rising to >10% in those over 70. The most common causes are ischaemic heart disease (approximately 50%) and hypertension. Other causes include valvular disease, cardiomyopathy, arrhythmias, and congenital heart disease. Five-year mortality remains around 50%, making it a condition with prognosis comparable to many cancers.
Clinical Features
Symptoms
Breathlessness on exertion (early), progressing to orthopnoea and paroxysmal nocturnal dyspnoea
Fatigue and exercise intolerance
Ankle swelling (peripheral oedema)
Weight gain from fluid retention
Acute pulmonary oedema: sudden severe breathlessness, pink frothy sputum
Reduced urine output
Signs
Raised JVP
Displaced apex beat (cardiomegaly)
S3 gallop rhythm
Bibasal fine inspiratory crackles
Peripheral pitting oedema (ankles → sacral if bedbound)
Hepatomegaly and ascites (right heart failure)
Hypotension with cold peripheries (cardiogenic shock)
Investigations
First-line
NT-proBNP<400 pg/mL = HF unlikely. 400–2000 = refer for specialist assessment and echo within 6 weeks. >2000 = urgent referral and echo within 2 weeks
ECGMay show LVH, ischaemia, AF, bundle branch block. A completely normal ECG makes HFrEF very unlikely
BloodsFBC, U&Es (baseline for ACEi/MRA), LFTs, TFTs, HbA1c, lipid profile, ferritin/TSAT
Second-line
Transthoracic echocardiogramGold standard for confirming diagnosis — assesses LVEF, wall motion, valves, diastolic function
Chest X-rayCardiomegaly, upper lobe diversion, Kerley B lines, pleural effusions, alveolar oedema (bat-wing pattern)
Specialist
Cardiac MRITissue characterisation — useful if cardiomyopathy, infiltrative disease, or myocarditis suspected
Coronary angiographyIf ischaemic aetiology suspected and revascularisation is being considered
Right heart catheterisationHaemodynamic assessment in advanced HF or pre-transplant workup
1
First-line — start together and uptitrate
- ACE inhibitor (ramipril, enalapril) — or ARB if ACE inhibitor not tolerated (cough)
- Beta-blocker (bisoprolol, carvedilol, nebivolol) — start low, go slow
- Aim for maximum tolerated dose of both before adding further agents
2
Second-line — add when still symptomatic
- Mineralocorticoid receptor antagonist (spironolactone or eplerenone)
- Monitor K⁺ and renal function closely — risk of hyperkalaemia
3
Third-line — SGLT2 inhibitor (the "fourth pillar")
- Dapagliflozin or empagliflozin — now recommended for all HFrEF regardless of diabetes status
- NICE TA902/TA929 — significant mortality and hospitalisation benefit
4
Specialist options
- Sacubitril-valsartan (ARNI) — replaces ACEi in symptomatic HFrEF with LVEF ≤35% despite optimal therapy
- Ivabradine — if sinus rhythm and HR >75 bpm despite max beta-blocker
- Hydralazine + nitrate — for Afro-Caribbean patients or if ACEi/ARB not tolerated
- CRT (cardiac resynchronisation therapy) — if LBBB with QRS ≥150 ms
- ICD — primary prevention if LVEF ≤35% despite ≥3 months optimal therapy
- Loop diuretics (furosemide/bumetanide) for symptom relief — not disease-modifying
Complications
- Arrhythmias: Atrial fibrillation (most common), ventricular tachycardia/fibrillation (risk of sudden cardiac death)
- Renal impairment: Cardiorenal syndrome — progressive CKD from chronic low cardiac output
- Cachexia: Cardiac cachexia in advanced disease — poor prognosis marker
- Thromboembolism: Systemic embolism (especially if concomitant AF), DVT/PE from immobility
- Depression: Common comorbidity — screen and treat
- Acute decompensation: Precipitated by infection, arrhythmia, non-adherence, dietary indiscretion, new ischaemia
UKMLA Exam Tips
- 1NT-proBNP thresholds: <400 = unlikely, 400–2000 = echo within 6 weeks, >2000 = urgent echo within 2 weeks
- 2The "four pillars" of HFrEF: ACEi + beta-blocker + MRA + SGLT2i — examiners love asking the order
- 3Sacubitril-valsartan replaces the ACEi (must stop ACEi for 36 hours before switching — risk of angioedema)
- 4Do NOT give verapamil or diltiazem in HFrEF — negative inotropic effect
- 5If a question mentions an Afro-Caribbean patient not tolerating ACEi/ARB → hydralazine + isosorbide dinitrate
- 6Iron deficiency is common in HF (check ferritin/TSAT) — IV iron if ferritin <100 or TSAT <20%
practicetest your knowledge on heart failureApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — cardiovascular and beyond.
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