A 67-year-old man with a history of LAD stent placed 2 years ago presents with mild angina on heavy exertion(CCS I). He is on atenolol, amlodipine, aspirin, and atorvastatin. BP 110/65, pulse 58 bpm. Exercise stress test result: 8 min on a Bruce protocol, mild angina occurred, DTS score +4. Nuclear perfusion shows a small area of apical–lateral ischemia, with a summed stress score of +3. Coronary angiography shows 60% proximal LCx stenosis, 30% mid-LAD, 40% mid-RCA. What is the next step?