Sodium-glucose Transporter Type 2 Inhibition in Anthracycline-related Cardiotoxicity

Inclusion Criteria: * Patients with breast cancer between 18-70 years of age. * Patients with low to medium cardiovascular risk. * Patients scheduled for adjuvant or neo-adjuvant anthracycline therapy. * Patients who are able to give written informed consent to take part in the study. * Patients who can read and understand English. The current thresholds for defining cardiovascular risk for patients undergoing anthracycline chemotherapy are as follows: normal resting 12-lead electrocardiogram, plasma cardiac troponin I concentration \< 99th centile, serum brain natriuretic peptide concentration \<35 pg/mL or serum N-terminal pro-brain natriuretic peptide concentration \<125 pg/mL, left ventricular ejection fraction \>55%, global longitudinal strain \>-18% and healthy life-style (normal body-mass index, non-smoker). Low cardiovascular risk will allow for the presence of one abnormal life-style factor (body-mass index indicating obesity (\>30 kg/m2), current smoker or significant smoking history), or presence of only one of the following in the clinical history: hypertension, stage 1-2 chronic kidney disease, age 65-79 years, borderline left ventricular ejection fraction (50-54%) or elevated cardiac biomarkers. Medium cardiovascular risk will permit the combination of any 2-4 of the lifestyle or clinical history variables indicated above. Exclusion Criteria: * Patients with a known intolerance of dapagliflozin * Patients with high cardiovascular risk as specified by the most recent cardio-oncology guidelines. * Patients with significant renal impairment (estimated glomerular filtration rate \<45 mL/min/1.73 m2). * Patients with a previous cancer diagnosis. * Patients with known type 1 or 2 diabetes mellitus. We will not actively screen for diabetes. This is not done in clinical practice and there have been no issues. * Patients with a contraindication to magnetic resonance imaging. * Patients with prior exposure to anthracyclines. * Patients who cannot read and understand English. * Patients who are pregnant