A 60-year-old woman with type 2 diabetes for 8 years, established coronary artery disease and an eGFR of 60 mL/min/1.73 m² has an HbA1c of 8.4%. She is on metformin 1 g twice daily. According to Diabetes Canada, which additional medication is MOST appropriate to add to reduce both cardiovascular risk and improve glycaemic control?