Treatment of Diabetes in Patients With Systolic Heart Failure

Investigator Initiated Study to study the effects of Canagliflozin 100 milligrams (mg) vs Sitagliptin 100 mg on parameters of aerobic exercise capacity (peak oxygen consumption \[VO2\]) and ventilator efficiency (minute ventilation \[VE\]/carbon dioxide production \[VCO2\] slope) at cardiopulmonary exercise test (CPET) after 12 weeks of active treatment (primary endpoints). Blood pressure (BP), body water content, body composition, cardiac function, and diet will be also measured (secondary endpoints).