Test your medicine knowledge with the MKSAP challenge, in partnership with the American College of Physicians.

A 59-year-old woman is evaluated for continued substernal chest pain. She presented with exertional chest pain 6 months ago that occurred with minimal ambulation. She was evaluated with a stress nuclear medicine myocardial perfusion study that showed no ST-segment changes but a small area of inducible ischemia in the lateral area of the left ventricle and an ejection fraction of 45%. She was initially treated medically but has continued to have chest pain with exertion despite the addition of multiple antianginal agents. Medical history is significant for hypertension, hypercholesterolemia, and type 2 diabetes mellitus. She has a 30-pack-year smoking history but quit 1 year ago. Medications are aspirin, lisinopril, simvastatin, metformin, metoprolol, and long-acting nitroglycerin.

On physical examination, the patient is afebrile, blood pressure is 132/72 mm Hg, pulse rate is 68/min, and respiration rate is 16/min. BMI is 28. The remainder of her physical examination is normal.

Electrocardiogram is unchanged from the time of her stress test.

Which of the following is the most appropriate next step in management?

A. Cardiac catheterization
B. CT angiography
C. Dobutamine stress echocardiography
D. Continued medical therapy

MKSAP Answer and Critique

The correct answer is A. Cardiac catheterization.

This patient with stable angina pectoris with symptoms that are not adequately controlled on optimal medical therapy should undergo left heart catheterization for further evaluation and potential revascularization. Her myocardial perfusion imaging results are consistent with ischemic coronary artery disease (CAD); however, these findings alone would not be an indication for left heart catheterization. In patients with stable angina pectoris, coronary revascularization has not been shown to improve morbidity or mortality, and thus is not indicated in patients whose symptoms are able to be controlled with optimal medical therapy. However, in patients with coronary ischemia who fail to respond to adequate antianginal therapy, such as this patient, coronary angiography is indicated to evaluate for possible revascularization to control her angina symptoms. Catheterization may allow for percutaneous intervention to address a coronary occlusion leading to her angina symptoms, or assessment for the need for surgical revascularization if extensive or complex CAD is present.

CT angiography is an emerging technology for the noninvasive evaluation of the coronary arteries. Although it may be able to confirm the diagnosis of CAD in this patient, it would not allow the opportunity for percutaneous coronary intervention, if possible. The use of CT angiography to estimate the need or benefit of coronary artery bypass grafting also has not been established. Therefore, this study would not be indicated in this clinical setting.

Dobutamine stress echocardiography is typically used to evaluate for ischemic CAD in patients who are unable to exercise. However, in this patient with documented coronary ischemia established by a nuclear medicine myocardial perfusion study, there would be no benefit to performing this alternative diagnostic study for ischemia.

Because this patient remains symptomatic with restrictions on her quality of life, continuing her current medical therapy without additional intervention would not be appropriate.

Key Point

• Patients with stable angina not adequately controlled with optimal medical therapy should undergo coronary angiography to evaluate for possible revascularization.

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