About this study Individuals receiving dialysis are at risk of heart failure and heart-related death. There is an urgent need for treatments that reduce the risk of these problems in patients that require dialysis. Spironolactone is a medication used to prevent heart failure and related deaths in patients that do not require dialysis. It works by blocking a hormone (aldosterone) in your body that causes high blood pressure and can damage the heart. Although spironolactone is very effective in patients that do not require dialysis, we do not know if spironolactone is effective in dialysis patients. Our research will help determine if spironolactone reduces heart failure and heart related deaths in dialysis patients. Eligibility criteria Inclusion Age ≥45 years or ≥18 with a history of diabetes On dialysis ≥ 90 days On either Haemodialysis prescribed at least 2 treatments per week or Peritoneal dialysis prescribed with at least 1 exc