A 43-year-old woman is evaluated for a 1-month history of chest discomfort. She states that she experiences a vague pressure-like sensation in her chest that occurs intermittently, with each episode lasting less than 5 minutes. She has had approximately two episodes each week, and several have seemed to be associated with exertion but also appear to have resolved after taking antacids. Her medical history is significant for hypertension. Her only medication is lisinopril. She is a current smoker with a 15-pack-year history. Family history is negative for coronary artery disease.
On physical examination, the patient is afebrile, blood pressure is 132/78 mm Hg, pulse rate is 85/min, and respiration rate is 12/min. BMI is 32. Cardiopulmonary examination is unremarkable, as is the remainder of her physical examination.
An electrocardiogram shows sinus rhythm, normal PR and QRS intervals, and no ST-segment or T-wave abnormalities or Q waves.
An exercise electrocardiographic treadmill test is performed. The patient is able to exercise for 4 minutes to a heart rate of 82% of the maximum predicted and energy expenditure of 4 metabolic equivalents until the study is discontinued because of fatigue. Testing did not reproduce her symptoms, and there were no significant electrocardiographic changes with exercise.
Which of the following is the most appropriate next step in management?