Key Facts

Heart failure is a complex clinical syndrome resulting from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood. It is classified by left ventricular ejection fraction (LVEF) into HFrEF, HFmrEF, and HFpEF.

Epidemiology

• Prevalence: ~1-2% of UK adults; ~900,000 people affected
• Incidence: ~200,000 new diagnoses per year in the UK
• Increases with age: ~10% in those >70 years
• 5-year mortality: ~50% (worse than many cancers)
• Leading cause of hospitalisation in those >65 years
• Annual NHS cost: >£2 billion

Aetiology

HFrEF:

• Ischaemic heart disease (~50%)
• Dilated cardiomyopathy (idiopathic, alcohol, viral, familial)
• Valvular heart disease (aortic stenosis, mitral regurgitation)
• Hypertension
• Arrhythmia (tachycardia-mediated)

HFpEF:

• Hypertension (most common)
• Diabetes mellitus
• Obesity
• Atrial fibrillation
• Ageing

Pathophysiology

• Reduced cardiac output activates compensatory neurohormonal mechanisms:
  • RAAS activation → sodium/water retention, vasoconstriction
  • Sympathetic activation → tachycardia, increased contractility
  • ADH release → water retention
• Initially compensatory but become maladaptive: ventricular remodelling, fibrosis, further dysfunction
• Natriuretic peptides (BNP, ANP) released in response to myocardial wall stress — counter-regulatory but overwhelmed

Left Heart Failure

• Dyspnoea (exertional → orthopnoea → PND → at rest)
• Fatigue and exercise intolerance
• Bibasal fine crepitations
• Third heart sound (S3 gallop)
• Displaced apex beat (cardiomegaly)
• Tachycardia

Right Heart Failure

• Peripheral oedema (bilateral pitting)
• Elevated JVP
• Hepatomegaly (may be pulsatile in TR)
• Ascites
• Weight gain

NYHA Functional Classification

• Class I: no limitation of physical activity
• Class II: slight limitation; symptoms with ordinary activity
• Class III: marked limitation; symptoms with less than ordinary activity
• Class IV: symptoms at rest

Red Flags

• Acute decompensation: severe dyspnoea, pulmonary oedema
• Cardiogenic shock: hypotension, cold peripheries, oliguria
• Severe peripheral oedema with anasarca
• Syncope or presyncope

Bedside

• ECG: may show LVH, AF, pathological Q waves, bundle branch block
• Observations: HR, BP, SpO₂, RR, weight

Bloods

• NT-proBNP (or BNP): key diagnostic biomarker
  • NT-proBNP <400 pg/mL: heart failure unlikely
  • NT-proBNP 400-2000 pg/mL: refer for echocardiography within 6 weeks
  • NT-proBNP >2000 pg/mL: refer urgently within 2 weeks
• FBC: anaemia
• U&Es: renal function, electrolytes (before ACEi/MRA)
• LFTs: hepatic congestion
• TFTs: thyroid disease
• HbA1c: diabetes
• Iron studies: iron deficiency (common comorbidity)
• Lipid profile: IHD risk

Imaging

• Echocardiography: gold standard for diagnosis
  • LVEF, wall motion abnormalities, valvular disease, chamber dimensions, diastolic function
  • HFrEF: EF ≤40%
  • HFmrEF: EF 41-49%
  • HFpEF: EF ≥50% with evidence of diastolic dysfunction
• Chest X-ray: cardiomegaly, pulmonary congestion, Kerley B lines, pleural effusions
• Cardiac MRI: gold standard for EF measurement, myocardial characterisation (fibrosis, inflammation, infiltration)

Special Tests

• Coronary angiography: if ischaemic aetiology suspected
• Cardiac catheterisation: haemodynamic assessment
• Endomyocardial biopsy: if infiltrative disease suspected
• Genetic testing: if familial cardiomyopathy suspected

Non-pharmacological

• Fluid restriction: 1.5-2L/day if hyponatraemic or fluid overloaded
• Salt restriction: <6g/day
• Daily weight monitoring: gain >2kg in 3 days → increase diuretic/seek advice
• Exercise-based cardiac rehabilitation (NICE recommended)
• Smoking cessation
• Alcohol avoidance/moderation
• Annual influenza and COVID vaccination

Pharmacological

HFrEF — Quadruple therapy (initiate all within first 6 weeks):

1. ACEi/ARB (first-line) or ARNI (sacubitril/valsartan):

   • Ramipril 1.25mg → titrate to 10mg OD
   • Or sacubitril/valsartan 24/26mg BD → titrate to 97/103mg BD
   • ARNI preferred if still symptomatic on ACEi (PARADIGM-HF trial)

2. Beta-blocker (evidence-based):

   • Bisoprolol 1.25mg → titrate to 10mg OD
   • Or carvedilol 3.125mg BD → 25mg BD
   • CIBIS-II, MERIT-HF, COPERNICUS trials

3. Mineralocorticoid receptor antagonist (MRA):

   • Spironolactone 25-50mg OD or eplerenone 25-50mg OD
   • RALES trial (spironolactone), EMPHASIS-HF (eplerenone)

4. SGLT2 inhibitor:

   • Dapagliflozin 10mg OD or empagliflozin 10mg OD
   • DAPA-HF, EMPEROR-Reduced trials
   • Benefit regardless of diabetes status

Additional therapies:

• Loop diuretic: furosemide 20-250mg OD for fluid overload (symptom relief, not mortality benefit)
• Hydralazine + isosorbide dinitrate: if ACEi/ARB/ARNI not tolerated (A-HeFT trial; particular benefit in Black patients)
• Ivabradine 2.5-7.5mg BD: if HR >75 bpm in sinus rhythm despite max beta-blocker (SHIFT trial)
• IV iron (ferric carboxymaltose): if iron deficient (ferritin <100 or 100-299 with TSAT <20%) — FAIR-HF, AFFIRM-AHF
• Digoxin: if AF with HF, or persistent symptoms despite OMT in sinus rhythm (DIG trial)

HFpEF:

• SGLT2 inhibitor: empagliflozin (EMPEROR-Preserved) or dapagliflozin (DELIVER) — first drugs to show benefit
• Diuretics for fluid management
• Treat underlying conditions (HTN, AF, diabetes)

Surgical/Interventional

• CRT (cardiac resynchronisation therapy): EF ≤35% + LBBB + QRS ≥150ms + NYHA II-IV despite OMT
• ICD (implantable cardioverter-defibrillator): EF ≤35% despite ≥3 months OMT (primary prevention)
• Heart transplantation: refractory end-stage HF in selected patients
• LVAD (left ventricular assist device): bridge to transplant or destination therapy
• Valve intervention: if significant valvular disease contributing

Referral Criteria

• All new diagnoses: specialist heart failure team within 2 weeks if NT-proBNP >2000
• Refractory symptoms despite optimal therapy: advanced HF centre
• Consider palliative care if NYHA IV with poor prognosis

• 1-year mortality: ~20-30% after first hospitalisation
• 5-year mortality: ~50% (comparable to many cancers)
• Median survival after diagnosis: ~5 years
• Prognosis improved significantly with modern quadruple therapy
• NYHA class IV: 1-year mortality ~50-75%
• HFpEF mortality slightly lower than HFrEF but still substantial
• Key prognostic factors: LVEF, NYHA class, NT-proBNP, renal function, age

Landmark Heart Failure Trials Summary

NYHA Classification