This study will look at how participants' daily life is affected by their heart failure. The study will also look at the change in participants' body weight.

This study will compare the effect of semaglutide (a new medicine) compared to "dummy" medicine on body weight and heart failure symptoms.

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 and physical activity.

The study will last for about 59 weeks, that is a little more than 1 year. Participants will have 12 clinic visits with the study doctor.

• At 6 of the visits participants will have blood samples taken.
• At 5 of the visits participants will be asked to fill in a questionnaire
• At 4 of the visits participants will have to do a 6-minute walking test
• At 3 of the visits participants will have a test to check the heart.
• participants will have their eyes checked before or at the start of the study and at the end of the study

Women cannot take part if pregnant, breast-feeding or plan to become pregnant during the study period.

Inclusion Criteria:

• Male or female, age above or equal to 18 years at the time of signing informed consent.
• Body mass index (BMI) greater than or equal to 30.0 kg/m^2
• New York Heart Association (NYHA) Class II-IV
• Left ventricular ejection fraction (LVEF) greater than or equal to 45% at screening
• Diagnosed with T2D greater than or equal to 90 days prior to the day of screening
• HbA1c of below or equal to 10.0% as measured at the screening visit

Exclusion Criteria:

• A self-reported change in body weight greater than 5 kg (11 lbs) within 90 days before screening irrespective of medical records
• Uncontrolled and potentially unstable diabetic retinopathy or maculopathy. Verified by a fundus examination performed within 90 days prior to screening or in the period between screening and randomisation. Pharmacological pupil-dilation is a requirement unless using a digital fundus photography camera specified for non-dilated examination.

According to the Novo Nordisk disclosure commitment on novonordisk-trials.com

Sponsor staff involved in the clinical trial is masked according to company standard procedures.