This is a study in adults with chronic heart failure. People with chronic heart failure may need to be hospitalised for their condition. Some people with chronic heart failure may eventually die from their condition. The purpose of the study is to find out whether a medicine called empagliflozin lowers the chances of patients having to go to hospital for heart failure and whether it improves their survival. The study is open to patients with a type of chronic heart failure called chronic heart failure with preserved ejection fraction.