Research Study to Investigate How Well Semaglutide Works in People Living With Heart Failure and Obesity

This study will look at how the participants daily life is affected by their heart failure. The study will also look at the change in participants body weight from the start to the end of the study. This is to compare the effect on heart failure symptoms and on body weight in people taking semaglutide (a new medicine) to people taking "dummy" medicine. Participants will either get semaglutide or "dummy" medicine - which treatment participants get is decided by chance. Participants will need to take 1 injection once a week. The study medicine is injected with a thin needle in a skin fold in the stomach area, thigh or upper arm. During the study participants will have talks with the study staff about healthy lifestyle choices including healthy food and physical activity. The study will last for approximately 59 weeks. Participants will have 11 clinic visits and 1 phone call with the study doctor. Women: Women cannot take part if they are pregnant, breast-feeding or plan to become pregnant during the study period.