Left Ventricular Functional Changes of Uncontrolled Diabetes by Dapagliflozin Treatment Trial

Inclusion Criteria: * Male or female affected by type 2 diabetes mellitus (T2D) for at least 6 months. * Age ≥ 20 and ≤ 80 years. * HbA1c levels 7.1%\~9.0% . * On stable (at least 3 months) antidiabetic therapy with SGLT2 inhibitors naive. * On stable (at least 3 months) cardio-active therapies (e.g. anti-hypertensive drugs, diuretics or drugs for hyperlipidemia). * Preserved kidney function as defined by estimated glomerular filtration rate(eGFR)\> 60 mL/min/1.73m2. * Preserved left ventricular function defined as EF ≥ 50% by echocardiographic screening. Exclusion Criteria: Subjects should not enter the study if any of the following exclusion criteria are fulfilled: * Involvement in the planning and/or conduct of the study (applies to both Investigator staff and/or staff at the study site). * Previous enrolment or randomisation in the present study. * Participation in another clinical study with an investigational product during the last 3 months. The exclusion criteria that follow are for example only; include, exclude, modify or add other criteria as appropriate. * Refuse or inability to give informed consent. * Patients unlikely to comply with the protocol or unable to understand the nature and possible consequences of the study. * Employees of the investigator or study centre (i.e. principal investigator, sub-investigator, study coordinators, other study staff, employees, or contractors of each), with direct involvement in the proposed study or other studies under the direction of that investigator and/or study centre, as well as family members of the employees or the investigator. * Pregnancy or active breast feeding. * History of hospitalization for heart failure. * History of stage C or D heart failure. * History of myocardial infarction. * History of cardiac dysrhythmia. * Patients with a known hypersensitivity to Dapagliflozin or any of the excipients of the product.