REDEFINE 3: A Research Study to See the Effects of CagriSema on Heart Disease in People Living With Obesity and Diseases in the Heart and Blood Vessels

This study will look at the effects of CagriSema on cardiovascular events (for example heart attack and stroke) in people living with obesity and cardiovascular disease. Participants will either get CagriSema or a dummy medicine which has no effect on the body. Which treatment participants will get will be decided by chance. Participant's chance of getting CagriSema or placebo is the same. Participants will take one injection once a week. The study medicine will be injected briefly with a thin needle, typically in the stomach, thighs or upper arms. The study will last for about 3 years. Participants will have 22 clinic visits with the study doctor or study staff. Women cannot take part if pregnant, breastfeeding or plan to get pregnant during the study period. Women who are able to become pregnant must use highly effective birth control and will be counselled on the use of birth control.

Inclusion Criteria:Male or femaleAge above or equal to 55 years at the time of signing informed consentBody mass index (BMI) greater than or equal to (>=) 30.0 kilograms per meter square (kg/m^2)Established CVD as evidenced by at least one of the following:Prior myocardial infarctionPrior stroke (ischemic or haemorrhagic stroke)Symptomatic peripheral arterial disease (PAD) defined as at least one of the following:Intermittent claudication with an Ankle-brachial index (ABI) less than (<) 0.85 at restIntermittent claudication with a >= 50% stenosis in a lower extremity peripheral artery documented by X-ray angiography, magnetic resonance (MR) angiography, computed tomography (CT) angiography or Doppler ultrasoundPrior revascularization procedure of a lower extremity peripheral arteryLower extremity amputation at or above ankle due to atherosclerotic disease (excluding e.g., trauma or osteomyelitis)For participants with T2D at screening the following inclusion criteria also apply:Diagnosed with type 2 diabetes mellitus (T2D) >= 180 days before screeningHbA1c 7%-10% (53-86 millimoles per mole [mmol/mol]) (both inclusive), as measured by central laboratory at screeningTreatment with either:Lifestyle intervention alone1-3 marketed oral antidiabetic drugs (OAD)s (metformin, α-glucosidase inhibitors (AGI), glinides, sodium-glucose co-transporter 2 inhibitor (SGLT2i), dipeptidyl peptidase 4 (DPP4)-inhibitors, thiazolidinediones, or sulphonylureas (SU) as a single agent or in combination) according to local labelBasal insulin alone or in combination with up to two marketed OADs, all according to local labelExclusion Criteria:Myocardial infarction, stroke, hospitalization for unstable angina pectoris or transient ischaemic attack within 60 days before screeningPlanned coronary, carotid or peripheral artery revascularisation known on the day of screeningHeart failure classified as being in New York Heart Association (NYHA) Class IV at screeningTreatment with any glucagon-like peptide-1 (GLP-1) receptor agonist (RA) or a medication with GLP-1 activity within 90 days before screeningEnd stage renal disease defined as estimated glomerular filtration rate (eGFR) < 15 millileters per minutes per 1.73^2 (mL/min/1.73 m^2), as measured by the central laboratory at screeningChronic or intermittent haemodialysis or peritoneal dialysis