Epidemiology and pathophysiology of heart failure

Heart failure is a syndrome characterized by dyspnoea, fatigue and fluid retention. The diagnosis of heart failure remains clinical: there is currently no single diagnostic investigation that can be considered as a ‘gold standard’. The syndrome generally affects middle-aged and elderly men and women, and causes substantial morbidity and reduces life expectancy. Prevalence is around 2% in the general population, rising steeply with age. The incidence of heart failure is 0.1–0.3% per year, but ten-fold higher in the elderly. Both incidence and prevalence are higher in men than in women. In developed countries, coronary artery disease accounts for two-thirds of cases. The prognosis of heart failure is poor with more than 40% of people dying within 18 months of a new diagnosis. The pathophysiology of the syndrome includes haemodynamic, autonomic and neurohormonal changes leading to progressive cardiac dysfunction, often accompanied with ventricular dyssynchrony, cardiac arrhythmias, renal dysfunction, anaemia, and cachexia. Therapy can be targeted to counteract these abnormalities, with increased use of angiotensin converting enzyme inhibitors, beta-blockers and aldosterone antagonists improving prognosis.