What is heart failure?

Heart failure (HF) is a clinical syndrome in which the heart cannot pump enough blood to meet the body's demands, or can only do so at abnormally elevated filling pressures. It is a chronic, progressive condition affecting over 500,000 Australians. Despite its name, heart failure does not mean the heart has stopped — it means the heart is not working as efficiently as it should.

Types of heart failure

• HFrEF (reduced ejection fraction): The heart muscle is weakened and contracts poorly. Ejection fraction (EF) ≤40%. Formerly called 'systolic heart failure'.
• HFpEF (preserved ejection fraction): The heart muscle contracts normally but is stiff and does not relax properly. EF ≥50%. Most common in older women with hypertension and diabetes.
• HFmrEF (mildly reduced EF): EF 41–49%. A transitional category with features of both HFrEF and HFpEF.

Heart failure affects over 600,000 Australians and is the leading cause of hospitalisation in those over 65. It carries a higher 5-year mortality than many common cancers.

Symptoms of heart failure

• Breathlessness on exertion — the earliest and most common symptom
• Orthopnoea — breathlessness when lying flat, relieved by sitting up
• Paroxysmal nocturnal dyspnoea (PND) — waking at night gasping for breath
• Ankle, leg and abdominal swelling (oedema)
• Fatigue and exercise intolerance
• Rapid weight gain due to fluid retention (>2 kg in 2 days)
• Persistent cough or wheeze
• Reduced urine output during the day; nocturia at night
• Loss of appetite and nausea (right heart failure)

Common causes

• Coronary artery disease and prior myocardial infarction — most common cause of HFrEF
• Hypertension — leading cause of HFpEF
• Valvular heart disease (aortic stenosis, mitral regurgitation)
• Dilated, hypertrophic or restrictive cardiomyopathy
• Atrial fibrillation (tachycardia-mediated cardiomyopathy)
• Diabetes mellitus
• Cardiotoxic medications (anthracyclines, trastuzumab)
• Alcohol excess
• Viral myocarditis

Heart failure is a clinical diagnosis supported by investigations. No single test is diagnostic.

• Echocardiogram: The cornerstone investigation. Measures ejection fraction, wall motion, valve function, filling pressures and right heart assessment.
• BNP / NT-proBNP: Biomarkers of cardiac stretch. Elevated levels confirm heart failure; a normal value makes heart failure unlikely. Used for diagnosis and monitoring.
• 12-lead ECG: Identifies underlying arrhythmias, conduction disease, left ventricular hypertrophy or prior MI.
• Chest X-ray: Assesses cardiomegaly and pulmonary oedema.
• Blood tests: Full blood count, renal function, electrolytes, liver function, thyroid function, iron studies (iron deficiency is present in up to 50% of HF patients).
• Holter monitor: If AF or other arrhythmia is suspected as a contributing cause.
• CT coronary angiography: To exclude coronary artery disease as an underlying cause in new-onset HF.

NYHA Functional Classification

Modern heart failure therapy for HFrEF is highly effective. Four drug classes form the "fantastic four" of guideline-directed therapy:

• ACE inhibitor or ARNI (sacubitril/valsartan): Reduces mortality and hospitalisation. ARNI (Entresto) is preferred over ACE inhibitors where tolerated.
• Beta-blocker (carvedilol, metoprolol succinate, bisoprolol): Reduces mortality by up to 35% in HFrEF.
• MRA (spironolactone or eplerenone): Reduces mortality; also treats fluid retention.
• SGLT2 inhibitor (dapagliflozin or empagliflozin): Reduces hospitalisations and cardiovascular death in both HFrEF and HFpEF. PBS-listed in Australia.

Additional treatments

• Diuretics (frusemide) — for fluid congestion and symptom relief
• Iron replacement — IV ferric carboxymaltose improves symptoms and reduces hospitalisation in iron-deficient HF
• Implantable cardioverter-defibrillator (ICD) — for sudden death prevention in severe HFrEF
• Cardiac resynchronisation therapy (CRT) — for HFrEF with left bundle branch block
• Treatment of underlying cause (revascularisation, valve repair/replacement)

Heart failure is a serious condition with a significant mortality burden. However, outcomes have improved dramatically with modern guideline-directed therapy.

• Overall 5-year survival is approximately 50–60%, but this varies significantly by severity and aetiology
• HFrEF has better evidence-based therapies and outcomes may improve substantially with optimised treatment
• Regular specialist follow-up, medication optimisation and self-monitoring significantly improve prognosis
• Early detection and treatment of decompensation (weight gain, increasing breathlessness) reduces hospitalisation

Many cases of heart failure are preventable through aggressive management of modifiable risk factors:

• Control blood pressure — target below 130/80 mmHg
• Optimise cholesterol and LDL-C
• Manage diabetes with cardioprotective agents (SGLT2 inhibitors, GLP-1 agonists)
• Stop smoking
• Limit alcohol intake
• Regular physical activity (150 min/week moderate intensity)
• Maintain healthy weight
• Treat sleep apnoea
• Avoid cardiotoxic medications where possible or monitor closely when required

• Weigh yourself daily — report a gain of >2 kg in 2 days to your doctor
• Restrict fluid intake to 1.5–2 litres per day if advised
• Limit dietary sodium to <2 g/day
• Participate in a cardiac rehabilitation programme
• Stay up to date with flu and pneumococcal vaccinations
• Carry a medication list and a 'heart failure action plan'
• Have an advance care plan discussion with your family and medical team