A 59-year-old man attends for review 6 weeks after an uncomplicated ST-elevation myocardial infarction treated with primary PCI. He is pain free and undergoing cardiac rehabilitation. His current medications are aspirin 100 mg daily, atorvastatin 20 mg nightly, perindopril 4 mg daily and metoprolol succinate 47.5 mg daily. His LDL-cholesterol is 2.2 mmol/L. What change to his lipid-lowering therapy is most appropriate?