Heart Failure
In developed countries, approximately 1–2 % of the adult population has heart failure (HF), and the prevalence of this cardiovascular disease increases with age.1,2 HF can occur in the presence or absence of reduced left ventricular ejection fraction (LVEF), known as HF with reduced ejection fraction (HF-rEF) and HF with preserved ejection fraction (HF-pEF), respectively. The most widely studied of these is HF-rEF, which is particularly prevalent in men with ischaemic heart disease.3 HF-pEF is present in 40–50 % of HF patients.4,5 It is more prevalent in women and the underlying aetiology is more often non-ischaemic.3,6 Despite these differences, the negative prognostic impact of both HF-rEF and HF-pEF appears to be similar.6 The prevalence of renal disease and sleep-disordered breathing (SDB) is similar in patients with HF-rEF or HF-pEF, but the profile of other co-morbidities differs, with pulmonary disease, anaemia and obesity tending to be more prevalent in HF-pEF patients.7 Even with the wide range of therapeutic options available for patients with HF-rEF and treatment being optimised according to current guideline recommendations, most HF-rEF patients will eventually die from progressive disease; for HF-pEF there are still no evidence-based treatments available, so the focus is mainly on treatment of co-morbidities and optimising risk factors.3