Your doctor has diagnosed you with HF. You are being asked to consider voluntary participation in a research study of CCM treatment with the Optimizer System, sponsored by Impulse Dynamics (USA) Inc. CCM with the Optimizer System was developed many years ago to treat patients with HFrEF and is approved for use in the United States and in many countries outside the US. The purpose of this study is to determine whether CCM treatment will reduce the occurrence of cardiovascular mortality and heart failure hospitalizations in patients with an ejection fraction greater than or equal to 40% and less than or equal to 60%. While the Optimizer system is approved for use in HFrEF patients, it is considered investigational for patients with an ejection fraction >45% in the US.