A 55-year-old man presents with gradually increasing shortness of breath and leg swelling over the past month. He has also noticed orthopnea and paroxysmal nocturnal dyspnea. He takes simvastatin for hypercholesterolemia and hydrochlorothiazide for hypertension. Blood pressure is 140/90 mm Hg; there is mild jugular venous distension, soft bibasilar crackles, an S3 gallop, and minimal pedal edema. An echocardiogram shows left ventricular ejection fraction (LVEF) of 40% without segmental wall-motion abnormality. The patient desires to keep medications to a minimum What change in his management would you recommend at this time?