Coronary Artery Disease

The goals of physical examination in patients with suspected or known coronary artery disease
(CAD) are to exclude noncoronary causes of chest pain, including aortic stenosis, hypertrophiccardiomyopathy, and aortic dissection; and to detect any signs of heart failure. Then, the most
appropriate diagnostic test (Table 3) depends on the pretest probability of disease, estimated
from thedescription of symptoms, age, and sex.
The standard diagnostic approach in patients with suspected or known coronary artery disease
continues to be history and physical examination followed by stresstesting when appropriate.
Exercise stress testing is preferred because it provides an objective measure of functional status
in addition to detection of ischemia. In patients who cannot exercise, stresstesting with
pharmacologic agents that increase the heart rate–blood pressure product (such as dobutamine)
or result in relative inequality in myocardial blood flow (such as adenosine) areappropriate.
Exercise electrocardiographic (ECG) stress testing with ECG monitoring alone is appropriate
when the resting ECG is normal. Any resting ST-segment changes reduce diagnostic accuracy,
and ECGstress testing is not useful with conditions such as pre-excitation (Wolff-Parkinson-
White syndrome), greater than 1-mm ST-segment depression, and left bundle branch block.
Following an abnormalresting ECG or with pharmacologic stress testing, echocardiographic or
nuclear imaging is needed. Based on a recent meta-analysis, echocardiographic and nuclear
stress imaging are equivalent for thediagnosis of ischemia with a negative predictive value of
98% for adverse cardiovascular outcomes over the next 3 years.
Coronary angiography is appropriate when the stress test is consistent withCAD, particularly if
there is a large area of myocardium at risk. In patients with a very high pretest probability of
disease, coronary angiography is an appropriate initial diagnostic test.
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