The DAPA-MEMRI Trial

The study is designed to investigate the myocardial calcium handling in patients with heart failure with or without type 2 diabetes mellitus and if Dapagliflozin (study drug) improves the myocardial calcium handling in patients with heart failure and diabetes mellitus. We propose to conduct this study in two parts. 1. OBSERVATIONAL CROSS-SECTIONAL STUDY An observational cross-sectional study will be undertaken to compare myocardial calcium in patients with diabetes mellitus and normal left ventricular ejection fraction (n=20), patients with heart failure in the absence of diabetes mellitus (n=60), and patients with both diabetes mellitus and heart failure (n=60). They will be compared with healthy volunteers (n=20). There will be an initial meeting, where informed consent will be documented and a medical assessment including blood tests will be undertaken as well as an echocardiogram will be performed. Healthy volunteers will only undergo Manganese enhanced cardiac MRI scan. The other cohorts will undergo a gadolinium enhanced cardiac MRI scan on their first visit. On a subsequent visit, they will undergo 1 cardiac Manganese enhanced Manganese MRI scan (MEMRI) which lasts 45-60 minutes. Participants will be monitored with blood pressure and ECG monitoring throughout the MEMRI scan. Patients will be offered an anti-sickness medication if required following the MEMRI scan. 2. RANDOMISED CONTROLLED TRIAL We will undertake a randomised double-blind placebo controlled trial of patients with heart failure with (n=60) and without (n=60) type 2 diabetes mellitus. These participants would have been recruited as part of the observational study as described above from out-patient clinics at the Edinburgh Heart Centre. If all eligibility criteria are met, patients will be randomised to receive treatment with either Dapagliflozin 10 mg, or matched placebo, once daily for 6 months at a ratio of 1:1. Detailed clinical assessment including history and examination, blood sampling, electrocardiogram, echocardiogram and cardiac MRI will be collected at baseline, 1 and 6 months. There will also be a 3 month safety visit after randomisation to record any adverse events.