Heart failure

Overview

•Heart failure (HF) - clinical syndrome where the heart cannot generate sufficient cardiac output to meet metabolic demands, or only does so at the cost of elevated filling pressures
•UK prevalence 1-2%; mean age at diagnosis 75 years; ~50% dead within 5 years (comparable to malignancy)

Aetiology

Common causes
Coronary artery disease - most common (ischaemic cardiomyopathy)
Hypertension - pressure overload → LVH → diastolic dysfunction
Valvular disease - pressure or volume overload
Atrial fibrillation - reduces diastolic filling time by ~20%
Cardiomyopathy
High-output causes - thyroid disease, severe anaemia

Presentation

•Left heart failure - pulmonary venous congestion: exertional dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea (PND), bibasal fine crepitations
•Right heart failure - systemic venous congestion: peripheral oedema, raised JVP, hepatomegaly, ascites
•Key signs - displaced apex beat (LV dilatation), third heart sound (S3 gallop - highly specific for HF), raised JVP
•Orthopnoea - lying flat redistributes fluid into pulmonary circulation; PND - same mechanism occurring during sleep, waking patient 1-2 hours after lying down

Investigations

🥇 First-line

•NT-proBNP - key biomarker; raised due to ventricular wall stress
•NT-proBNP >2000 ng/L → urgent echo within 2 weeks; NT-proBNP 400-2000 ng/L → routine echo within 6 weeks; normal value makes HF unlikely
•12-lead ECG - rarely normal in HF; look for LVH, AF, LBBB, ischaemic changes; completely normal ECG makes HF unlikely
•Chest X-ray - ABCDE signs (see below)
•Bloods - U&E (baseline before ACEi/diuretics; hyponatraemia = poor prognosis), FBC, TFTs, LFTs (raised in right HF), HbA1c, lipid profile

🏆 Gold standard

•transthoracic echocardiography - confirms diagnosis, measures EF, identifies structural cause, guides treatment
🧠
CXR in HF - remember ABCDE: Alveolar oedema (batwing perihilar shadowing) | Basal Kerley B lines (interstitial oedema) | Cardiomegaly (cardiothoracic ratio >0.5) | Diversion of upper lobe blood (early sign) | Effusions (bilateral pleural transudates). Fluid in the horizontal fissure is also classical.

Management

•Conservative: salt restriction, fluid restriction if hyponatraemic, smoking cessation, alcohol reduction, weight optimisation, cardiac rehabilitation, annual influenza and one-off pneumococcal vaccination
•Symptom control (all HF): furosemide - loop diuretic for fluid overload
•HFrEF - four pillars of mortality-reducing therapy:
•ACE inhibitor (or ARB if ACEi not tolerated) - blocks RAAS
•Beta-blocker - blocks SNS-driven remodelling; reduces mortality ~35% in HFrEF
•Mineralocorticoid receptor antagonist (MRA) - e.g. spironolactone
•SGLT2 inhibitor - e.g. dapagliflozin / empagliflozin
•Device therapy: ICD if EF <35% (sudden cardiac death prevention); CRT if LBBB/wide QRS (dyssynchrony)
⚠️
Do NOT withhold beta-blockers in stable HFrEF out of fear of negative inotropy - long-term use reduces mortality by ~35%. Key caveats: start low, titrate slowly, and do NOT initiate during acute decompensation.

Complications

•Atrial fibrillation - cause and complication; worsens HF by reducing diastolic filling time (~20%) and loss of atrial kick; rate control with beta-blockers or digoxin
•Sudden cardiac death - VF/VT; leading cause of death in HFrEF; risk greatest with EF <35% → ICD
•Cardiorenal syndrome - reduced CO causes renal hypoperfusion; modest creatinine rise up to 30% acceptable when starting ACEi
•Acute pulmonary oedema - medical emergency; urgent IV diuresis, oxygen, sit upright
•Hepatic congestion - raised right-sided pressures → 'nutmeg liver'; rising bilirubin is a poor prognostic sign

Prognosis

•~50% dead within 5 years; mortality higher in HFrEF than HFpEF
•Poor prognostic markers: low EF, raised NT-proBNP, hyponatraemia, renal impairment, NYHA class IV, AF, wide QRS

Classification by ejection fraction

HF classification by EF
FeatureHFrEFHFmrEFHFpEF
EF<40%40-49%≥50%
Dominant mechanismSystolic dysfunctionMixedDiastolic dysfunction
Four-pillar therapyYes - evidence-basedEmerging evidenceLimited - symptom control