A 58-year-old man is evaluated in the cardiology clinic 12 days after suffering an anterior ST-elevation myocardial infarction that was treated with primary percutaneous coronary intervention. His current medications include aspirin, metoprolol, lisinopril, and high-intensity statin therapy. A transthoracic echocardiogram performed today shows an LVEF of 30% with anterior wall hypokinesis. He is otherwise euvolemic and asymptomatic. Which of the following is the most appropriate next step in managing his risk of sudden cardiac death?