About the study Chronic Obstructive Pulmonary Disease (COPD) is the third-leading cause of global health-related disease and deaths. Heart disease is very common in people diagnosed with COPD and is often the cause of health-related sickness and hospitalisations, causing 30 – 50% of deaths. Studies repeatedly show that heart disease is often not diagnosed in persons with COPD, and when it is diagnosed it is often under-treated. People with COPD are also commonly not included in clinical trials of drugs which treat heart disease and heart-related deaths. Beta (β)-blockers are medications often used to treat heart disease. In this study, we will be investigating whether pro-active treatment with a β-blocker in people with COPD can reduce heart-related events, such as strokes and heart attacks. This is important for people with COPD with either known or unknown underlying heart disease. The study also aims to investigate whether this treatment influences number of respiratory flare ups (exace