The research study is being done to see if ziltivekimab can be used to treat people who were admitted to hospital because of a heart attack. Ziltivekimab might reduce development of heart disease, thereby preventing new heart attacks or strokes. Participants will either get ziltivekimab (active medicine) or placebo (a dummy medicine which has no effect on the body). Which treatment participants get is decided by chance. The chance of getting ziltivekimab or placebo is the same. The participant will need to inject the study medicine into a flat skin surface in there stomach, thigh, or upper arm once every month. Ziltivekimab is not yet approved in any country or region in the world. It is a new medicine that doctors cannot prescribe. The study will last for about 2 years.