What is this summary about? This is a summary of the article describing the EMPEROR-Reduced study of empagliflozin, which was published in the New England Journal of Medicine. Empagliflozin (brand name Jardiance ® ) is a new drug therapy for the treatment of chronic heart failure. Chronic heart failure is a long-term condition where the heart cannot pump enough blood around the body, leading to symptoms such as shortness of breath, fatigue and build-up of too much water in the body (fluid retention). It also increases the risk for premature death. What was the EMPEROR-Reduced study? The EMPEROR-Reduced study looked at the effects of empagliflozin, a medication taken once daily, in people with reduced ejection fraction. This is a type of heart failure where insufficient blood is pushed out of the heart muscle as it contracts. The study was conducted because more evidence is needed on the effects of empagliflozin and similar drugs in people with heart failure, including those with reduced ejection fraction. The main aim of the EMPEROR-Reduced study was to see if empagliflozin reduces the risk of being taken to hospital for complications of heart failure or dying from heart disease. What happened during the study? Over 3700 people with heart failure and reduced ejection fraction were randomly given either empagliflozin or placebo (an identical pill lacking medication) daily for about 16 months. This was a double-blind study, which means that neither the participants nor the researchers knew which treatment participants were receiving. What were the results? After an average of 16 months of continuous treatment, fewer patients taking empagliflozin (13.2%) needed to be hospitalized for complications of heart failure than those taking placebo (18.3%). Also, fewer patients taking empagliflozin (1.6%) developed serious kidney problems than those taking placebo (3.1%). Side effects were generally similar in participants who received empagliflozin and those who received placebo, except for genital tract infections, which affected more participants who received empagliflozin (1.7%) than placebo (0.6%). What do the results mean? This study suggests that people with chronic heart failure with reduced ejection fraction may benefit from treatment with empagliflozin, mainly by needing to go to hospital less often because of complications of heart failure. Clinical Trial Registration: NCT03057977 (EMPEROR-Reduced study) ( ClinicalTrials.gov )