Heart failure: symptoms, causes and modern treatment

What is heart failure?

In heart failure, the heart muscle is weakened or stiff and cannot fill with or pump out blood effectively. Organs receive less oxygen, and fluid builds up in the lungs, abdomen and legs.

The European Society of Cardiology (ESC) describes three main types, based on the left ventricle's ejection fraction (EF) – the percentage of blood pumped out with each beat:

• reduced EF (40% or less) – the heart muscle squeezes weakly;
• mildly reduced EF (41–49%);
• preserved EF (50% or more) – the heart squeezes normally but is stiff and does not relax well; this is more common in older people, women and those with high blood pressure, obesity or diabetes.

Heart failure can develop gradually (chronic heart failure) or suddenly (acute decompensation), which needs hospital treatment.

Causes and risk factors

Heart failure is usually the result of another heart or blood vessel condition:

• coronary heart disease and a previous heart attack that has scarred the muscle;
• high blood pressure, which strains and thickens the heart over years;
• heart valve disease – narrowed or leaking valves;
• cardiomyopathies – inherited, inflammatory or caused by toxins such as alcohol and some cancer medicines;
• rhythm problems, especially atrial fibrillation with a fast heart rate;
• diabetes, obesity, chronic kidney disease, sleep apnoea and thyroid disease.

Controlling these risk factors is the best prevention. For the wider picture, see heart disease.

Heart failure symptoms

Symptoms often come on slowly and are easily put down to age or being unfit:

• breathlessness – at first on exertion such as climbing stairs, later even at rest;
• breathlessness lying flat, needing extra pillows, or waking at night short of breath;
• swollen ankles and legs, usually worse in the evening;
• rapid weight gain – 2 kg in two or three days – from fluid retention;
• tiredness, weakness and reduced exercise tolerance;
• a night-time cough, palpitations, poor appetite and a bloated abdomen.

Doctors grade severity using the NYHA classes, from class I (no symptoms with ordinary activity) to class IV (symptoms at rest).

How heart failure is diagnosed

If heart failure is suspected, the doctor takes a history, examines you and arranges tests:

• NT-proBNP or BNP – a blood marker that rises when the heart is under strain; a normal result makes heart failure unlikely.
• ECG – looks for rhythm problems and signs of a previous heart attack.
• Echocardiogram – the key test, measuring ejection fraction, chamber size, valves and pressures.
• Chest X-ray and blood tests – blood count, kidney function, salts, thyroid hormones, iron and glucose.
• Where needed, coronary angiography, cardiac MRI or genetic testing to find the cause.

Treating heart failure

For heart failure with reduced ejection fraction, ESC guidelines recommend four core medicine groups that have been shown to reduce hospital admissions and deaths, started as early as possible:

• angiotensin receptor–neprilysin inhibitors (ARNI) or ACE inhibitors;
• beta-blockers;
• mineralocorticoid receptor antagonists;
• SGLT2 inhibitors – first developed for diabetes, but effective in people without diabetes too.

Diuretics ("water tablets") remove excess fluid and ease breathlessness and swelling. SGLT2 inhibitors are also recommended for mildly reduced and preserved EF. Doses are increased step by step while blood pressure, pulse and kidney function are checked – do not stop medicines on your own.

Devices and procedures for suitable patients include an implantable cardioverter-defibrillator (ICD) to protect against dangerous arrhythmias, cardiac resynchronisation therapy (CRT), surgical or catheter valve treatment, and stenting or bypass surgery for blocked arteries. In severe, advanced heart failure, a left ventricular assist device (LVAD) or a heart transplant may be considered.

Acute worsening and outlook

Chronic heart failure can suddenly get worse – this is called acute decompensation. Common triggers include missed medicines, too much salt or fluid, infections, uncontrolled blood pressure, rhythm problems and certain medicines. In hospital, fluid is removed with intravenous diuretics, the trigger is treated and long-term medicines are adjusted. The first weeks after discharge are a vulnerable time, so a check-up with the cardiologist or GP should follow soon after you go home.

The outlook varies widely and depends on the cause, type and severity of heart failure, other conditions and how closely treatment is followed. In advanced heart failure with frequent admissions, palliative care helps with breathlessness and fatigue alongside cardiology treatment.

Self-care and daily life

What you do every day is part of the treatment:

• weigh yourself every morning and tell your team about a gain of more than 2 kg in three days;
• cut down on salt; any fluid limit should be set individually by your doctor;
• keep up regular, moderate physical activity, ideally through a cardiac rehabilitation programme;
• stop smoking and keep alcohol low;
• have flu, pneumococcal and COVID-19 vaccinations;
• avoid anti-inflammatory painkillers unless advised – they cause fluid retention;
• watch your mood – depression is common and treatable.

For practical eating advice, see a heart-healthy diet.

When to see a doctor

See your GP if you notice increasing breathlessness on exertion, swollen ankles, unexplained tiredness or need more pillows to sleep. They will arrange tests and, if needed, refer you to a cardiologist. If you are already being treated, contact your team about rapid weight gain or worsening swelling or breathlessness.

Call 112 (or your local emergency number) for severe breathlessness at rest, being unable to lie down because of breathlessness, coughing up pink frothy sputum, chest pain, fainting, or a very fast and irregular heartbeat.

Heart failure treatment abroad and in Türkiye

Patients from Bulgaria and elsewhere in Europe sometimes seek a second opinion or procedures – ICD or CRT implantation, catheter valve treatment, bypass surgery or LVAD assessment – at large accredited hospital groups in Istanbul. Before deciding, check the cardiologist's and cardiac surgeon's experience, ask for a written plan, and agree who will monitor the device and your medicines at home. Organisers such as New City Clinic coordinate the hospital, doctor, hotel, transfers and interpreter, while medical decisions remain with the treating team. Read more in heart surgery in Turkey.