Background: The aortic valve is like a door in the heart that lets blood flow out to the body. Over time, this valve can get worn out and become too narrow, leading to a condition called aortic stenosis. When this happens, the heart has to work extra hard to push blood through the narrow valve to supply the body with what it needs. This extra effort can cause the heart muscle to become abnormally thick or to have fibrosis. For people with aortic stenosis, this can lead to more problems like feeling out of breath, chest pain, and even needing to go to the hospital. It also increases the risk of dying from heart issues. There is a type of medication called Sodium Glucose Cotransporter 2 (SGLT2) inhibitors, which has been studied in people with weak heart muscle. These medicines were found to help the heart work better and improve the pumping of blood around the body. This can be promising for patients with aortic stenosis because it might make the heart muscle stronger and protect it from damage. Aim of research study: The aim of this study is to investigate whether the use of the drug empagliflozin, an SGLT2 inhibitor, prevents the formation of fibrosis or the abnormal thickening of the heart muscle in patients with aortic stenosis. Using advanced imaging techniques (such as echocardiography and cardiovascular magnetic resonance), we intend to study their effect on the heart muscle of patients with aortic stenosis. Study design: Patients with moderate aortic stenosis will be invited for participation. Eligible consenting patients will have a baseline assessment with cardiac MRI scan, echocardiography, cardiopulmonary exercise test and validated quality of life questionnaires. They will then be randomised to receive either the SGLT2i for 6 months, or standard of care. All patients will undergo the same tests at 6 months. This way, we aim to investigate the potential changes in the heart muscle and whether the SGLT2 inhibitor prevents fibrosis or hypertrophy.