A 58-year-old man from Delhi presents with progressive dyspnea on exertion for 3 months, orthopnea, and paroxysmal nocturnal dyspnea. He has a history of hypertension (on amlodipine 5 mg daily) and type 2 diabetes mellitus. On examination, BP is 148/92 mmHg, HR 102/min, JVP elevated at 8 cm, bilateral basal crackles, and a displaced apical impulse. ECG shows left ventricular hypertrophy with strain pattern. Echocardiography reveals LVEF 35%, global hypokinesis, and diastolic dysfunction. Which of the following is the most appropriate next step in management?