A 54‑year‑old woman with type 2 diabetes (diagnosed 8 years ago) and hypertension is reviewed in general practice. Her BMI is 31 kg/m², blood pressure 132/78 mmHg on an ACE inhibitor, and HbA1c is 7.6% (60 mmol/mol) on metformin 1 g twice daily. She has established coronary artery disease following an NSTEMI 2 years ago. According to Australian type 2 diabetes algorithms, which addition to metformin is preferred to improve cardiovascular outcomes?