A 62-year-old man with a 20-year history of type 2 diabetes mellitus (HbA1c 8.2%), hypertension controlled on amlodipine, and mild dyslipidemia is scheduled for elective laparoscopic cholecystectomy. On pre-anesthetic evaluation, his vital signs are stable, oxygen saturation 98% on room air, and he has no dyspnea or chest pain. His ECG shows normal sinus rhythm with no ischemic changes. What is the most appropriate next step in his pre-anesthetic workup?