A 68-year-old man with heart failure with reduced ejection fraction (HFrEF) is reviewed. He is currently taking Ramipril 10mg OD and Bisoprolol 10mg OD. He remains symptomatic (NYHA Class II). His eGFR is 50 mL/min and potassium is 4.5 mmol/L. According to current NICE guidelines, which two medications should be added next?