A 66 year old man presents with intermittent central chest pressure for the past 3 hours. The pain occurs with walking two blocks and improves with rest. He has hypertension and hyperlipidemia. Vital signs are stable, ECG shows normal sinus rhythm without ischemic changes, and high sensitivity troponin is normal at 0.5 hours and 2 hours after presentation. He has no high risk features and his pretest probability of coronary artery disease is low to intermediate by structured risk assessment. What is the most appropriate next diagnostic strategy?