Does a negative stress echocardiogram (echo) rule out Coronary Artery Disease (CAD)?

From the Guidelines

A negative stress echocardiogram does not definitively rule out coronary artery disease (CAD), though it is reassuring. While a negative stress echo indicates that no significant stress-induced wall motion abnormalities were detected during the test, it has limitations. The test has approximately 85-90% sensitivity, meaning it can miss some cases of CAD, particularly single-vessel disease or mild coronary stenosis that doesn't cause detectable wall motion abnormalities during stress, as noted in studies evaluating the diagnostic accuracy of stress echocardiography 1. False negatives are more common in women, patients with left bundle branch block, and those taking beta-blockers during testing. Additionally, a negative test only reflects the patient's condition at that specific time; CAD can develop or progress later. Clinical context remains crucial - if a patient has significant risk factors or concerning symptoms despite a negative stress echo, further evaluation with other modalities like coronary CT angiography or invasive coronary angiography might be warranted, as suggested by guidelines for the evaluation of primary care patients with chronic stable angina 1. Regular follow-up and continued attention to cardiovascular risk factor management remain important even after a negative stress echo. Some key points to consider include:

• The presence or absence of inducible myocardial wall-motion abnormalities has useful predictive value in patients undergoing exercise or pharmacologic stress echocardiography 1
• Negative results on stress echocardiography also denote a low cardiovascular event rate during follow up 1
• Left bundle-branch block, or an electronically paced ventricular rhythm, reduces the accuracy and specificity of exercise myocardial perfusion imaging, exercise echocardiography, and dobutamine echocardiography, making adenosine or dipyridamole myocardial perfusion imaging preferred in such patients for diagnosis and risk stratification 1.

From the Research

Stress Echo Results

• A negative stress echocardiography (NSE) result is associated with low cardiovascular morbidity and overall mortality 2
• The negative predictive value (NPV) of stress echocardiography is high, but not 100%, meaning that a negative result does not completely rule out coronary artery disease (CAD) 3
• A normal stress test does not rule out a non-obstructive coronary etiology of angina, nor does it negate the need for comprehensive invasive testing 4

Predictors of CAD

• Predictors of a new CAD lesion at 1 year include male gender, diabetes, personal history of CAD, and abnormal non-ischemic SE 2
• MACE occurred more frequently among older (≥65 years) men with preexisting diabetes, hypertension, and/or hyperlipidemia 3
• Endothelial dysfunction, microvascular dysfunction, and/or a myocardial bridge may be present in patients with angina and no obstructive CAD, and stress echocardiography may not be able to identify these occult abnormalities 4

Diagnostic Accuracy

• Stress echocardiography has excellent clinical efficacy, is safe, and is cost-effective for the diagnosis and risk stratification of patients with known or suspected CAD 5
• Non-invasive coronary angiography by computed tomography has emerged as a diagnostic tool with high accuracy and prognostic value, challenging the role of stress testing as the initial imaging modality in patients with suspected CAD 6