Heart failure is a common condition and becoming more common. Many treatments have been evaluated in large clinical trials during the last few decades. These trials can be criticized but do provide an evidence base for treatment, probably greater than for most other clinical conditions. Weaknesses exist in relation to age, ejection fraction, and gender. Most trials have included patients 10 years younger than those in the general population. There is little evidence for efficacy in patients with a near normal ejection fraction. Few women have been included in trials.