Can a patient have a critical coronary lesion with a normal Stress Echocardiogram (SECHO)?

Critical Coronary Lesions Can Occur Despite Normal Stress Echocardiography Results

Yes, it is possible for a patient to have a critical coronary lesion despite having a normal stress echocardiogram (SECHO). While stress echocardiography is a valuable diagnostic tool, it has inherent limitations in sensitivity that can result in false negative results, particularly in certain patient populations and lesion types.

Diagnostic Performance of Stress Echocardiography

Stress echocardiography relies on detecting wall motion abnormalities induced by stress as a marker of significant coronary artery disease. According to ACC/AHA guidelines, the sensitivity of stress echocardiography for detecting significant coronary artery disease varies based on several factors:

• For single-vessel disease, sensitivity ranges from 32-96% 1
• For multi-vessel disease, sensitivity ranges from 24-96% 1
• The negative predictive value ranges from 60-95% 1

This means that even with a normal stress echocardiogram, there remains a possibility (approximately 5-18%) of missing significant coronary artery disease.

Scenarios Where Critical Lesions May Be Missed

1. Single-Vessel Disease

• Single-vessel disease, particularly involving distal vessels or diagonal branches, may not produce wall motion abnormalities detectable on stress echocardiography
• The sensitivity for single-vessel disease can be as low as 32% in some studies 1

2. Balanced Ischemia

• In patients with multi-vessel disease or left main disease with balanced reduction in coronary flow, wall motion abnormalities may not be apparent due to global rather than regional hypoperfusion

3. Submaximal Stress

• Patients unable to achieve target heart rate may have false negative results
• The inability to perform an exercise test is itself a negative prognostic factor 1

4. Technical Factors

• Poor acoustic windows limiting visualization of wall segments
• Operator experience and interpretation variability
• Suboptimal image quality

Clinical Evidence of False Negatives

Case reports have documented acute myocardial infarction occurring shortly after normal dobutamine stress echocardiograms. In one documented case, a patient developed an acute inferior ST-elevation MI just 2 hours after a normal dobutamine stress echocardiogram. Coronary angiography revealed a 60% stenosis of the proximal right coronary artery with a complex ulcerated lesion and intracoronary thrombus 2.

This suggests that myocardial infarction following a normal stress echocardiogram can occur not only in severe obstructive disease but also in moderate lesions that may become unstable due to plaque rupture or erosion.

Risk Stratification Considerations

Even in patients with angiographically confirmed significant coronary artery disease (≥70% stenosis), those with normal stress echocardiography results (no inducible ischemia) have a relatively low cardiac event rate of approximately 1.0% per year compared to 4.9% per year in those with abnormal results 3.

Recommendations for Clinical Practice

1. Recognize the limitations of stress echocardiography

   • No single non-invasive test is 100% sensitive for coronary artery disease
   • Normal results reduce but do not eliminate the possibility of significant CAD

2. Consider patient-specific factors that may affect test accuracy

   • Left bundle branch block or paced rhythm (reduces accuracy)
   • Inability to achieve adequate stress level
   • Poor acoustic windows

3. Integrate with clinical assessment

   • High clinical suspicion with typical symptoms despite normal SECHO may warrant further investigation
   • The 2024 ESC guidelines recommend considering the pre-test likelihood when interpreting test results 1

4. Consider alternative or additional testing when appropriate

   • Coronary CT angiography may be preferred in patients with low to moderate pre-test probability (5-50%) 1
   • Invasive coronary angiography should be considered in patients with very high clinical likelihood of disease (>85%) despite normal non-invasive testing 1

When to Consider Additional Testing Despite Normal SECHO

• Persistent typical angina symptoms despite normal stress results
• High-risk clinical features (diabetes, multiple risk factors)
• Known coronary artery disease with change in symptom pattern
• High Duke treadmill score with normal imaging (limited data suggest this may be an exception to the rule) 1

In conclusion, while a normal stress echocardiogram has good negative predictive value and generally indicates a favorable prognosis, clinicians should remain vigilant in patients with high clinical suspicion for coronary artery disease, as critical coronary lesions can be present despite normal stress echocardiography results.