**2. Heart failure**

Heart failure (HF) is one of the most common causes of death while it affects about 37.7 million people worldwide and was identified as an epidemic in 1997 [1, 2]. In majority of patients it can have a debilitating effect chronically if the initial insult is survived. The burden on the affected individual as well as the wider society is substantial. Poor exercise tolerance, chronic lethargy and depression with constant anxiety of sudden death together with frequent hospitalizations are among those factors limiting patients' quality of life (QOL). The burden to the society is highlighted by 1–4% of all hospital admissions in Europe and US being due to HF with an average stay of 5–10 days and readmission rates of about 25% within 1 month and 50% within 2 months after discharge [3].

Over the last two decades the management of HF has improved with optimal medical therapy including ACE-Inhibitors, β-Blockers, loop-diuretics and Spironolactone together with implantable defibrillators and resynchronisation devices. However the best available therapy for advanced HF is heart transplantation with the caveat that it is available for only very few patients who are deemed eligible to be accepted on the waiting lists and survive long enough for a suitable organ to become available. For the rest the outcome is very poor with an average survival of 50% at 5 years and 10% at 10 years after diagnosis of HF. This rate has not changed in the last 20 years whereas the survival when diagnosed with cancer has doubled in the last 40 years. Therefore there is much potential for alternative treatment options of which the ventricular assist devices present a real hope.
