A 67-year-old man with a history of anterior ST-segment elevation myocardial infarction (STEMI) three years earlier presented for routine follow-up in the heart failure clinic. His medical history included hypertension, type 2 diabetes mellitus, and dyslipidaemia. Despite adherence to guideline-directed medical therapy (GDMT), he reported persistent exertional dyspnoea and fatigue while performing moderate physical activities. He denied orthopnoea, paroxysmal nocturnal dyspnoea, or recent heart failure hospitalisations. Physical examination revealed a blood pressure of 112/68 mmHg, a heart rate of 68 beats/min, mild bilateral ankle oedema, and the absence of bibasal crackles. Echocardiography demonstrated a left ventricular ejection fraction (LVEF) of 30% with global left ventricular systolic dysfunction. Laboratory investigations showed an estimated glomerular filtration rate (eGFR) of 68 mL/min/1.73 m², serum creatinine of 1.1 mg/dL, serum potassium of 4.5 mmol/L, and elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP). Electrocardiography demonstrated normal sinus rhythm. His current medications included sacubitril/valsartan 97/103 mg twice daily, bisoprolol 10 mg once daily, empagliflozin 10 mg once daily, furosemide 40 mg once daily, atorvastatin 40 mg once daily, and aspirin 75 mg once daily. Despite receiving maximally tolerated background therapy, he remained symptomatic with New York Heart Association (NYHA) Functional Class II heart failure with reduced ejection fraction (HFrEF). His renal function and serum potassium were within acceptable limits, prompting consideration of further optimisation of GDMT.