Which stress test is appropriate for which type of patient (patient)?

Selecting the Appropriate Stress Test Based on Patient Characteristics

Standard exercise ECG testing is recommended as the initial test for patients with an intermediate pretest probability of coronary artery disease who have an interpretable ECG and can exercise adequately, while stress imaging tests should be used for patients with ECG abnormalities, inability to exercise, or high pretest probability of disease. 1

Exercise ECG Testing

Recommended for:

• Patients with intermediate pretest probability of coronary artery disease 1
• Patients with normal or near-normal resting ECG 2
• Patients capable of adequate exercise without disabling comorbidities 1
• Low-risk patients who require testing and have interpretable ECGs 1
• Young adults (<30 years) with suspected aortic stenosis for exercise capacity and blood pressure response assessment 1

Not recommended for:

• Patients with uninterpretable ECGs (e.g., left bundle branch block, ≥0.1 mV ST-depression on resting ECG, digitalis use) 1
• Patients unable to exercise due to physical limitations 1
• Patients with disabling comorbidities 1
• Routine screening of asymptomatic adults 1

Exercise Stress with Imaging (Nuclear MPI or Echocardiography)

Recommended for:

• Patients with intermediate to high pretest probability of coronary artery disease who have:
  • Uninterpretable ECG 1
  • Baseline ECG abnormalities (LBBB, ST-segment depression, LV hypertrophy with ST-T changes) 1
  • Patients taking digoxin 1
• Previous revascularization (PCI or CABG) with recurrent symptoms 1
• Assessment of functional severity of intermediate coronary lesions 1
• Patients who can exercise but need more accurate risk stratification than exercise ECG alone 1

Specific considerations:

• Exercise imaging is preferred over pharmacologic stress whenever patients can exercise adequately 1
• Exercise echocardiography shows comparable results to nuclear imaging for women 1
• Stress echocardiography has been shown to be more accurate than exercise ECG in patients ≥70 years with atypical angina or non-anginal pain 3

Pharmacologic Stress Testing with Imaging

Recommended for:

• Patients unable to exercise adequately 1
• Patients with left bundle branch block or paced ventricular rhythm 1
  • Specifically, dipyridamole or adenosine myocardial perfusion imaging is preferred 1
• Patients with intermediate to high pretest probability of coronary artery disease who cannot exercise 1
• Dobutamine stress testing for evaluation of mild aortic valve gradient with low LV ejection fraction 1

Specific considerations:

• For patients with LBBB or paced rhythm, exercise or dobutamine echocardiography is not recommended 1
• Pharmacologic stress with CMR can be useful for patients with uninterpretable ECG who have intermediate to high pretest probability 1
• Adenosine or dipyridamole myocardial perfusion imaging is preferred over dobutamine echocardiography in patients with LBBB 1

Coronary CT Angiography (CCTA)

Reasonable for:

• Patients with intermediate pretest probability who:
  • Have continued symptoms despite normal prior test results 1
  • Have inconclusive results from prior stress testing 1
  • Cannot undergo stress testing with imaging 1

Clinical Pearls and Pitfalls

1. Important caveat: The inability to perform an exercise test is itself a negative prognostic factor 1

2. Risk stratification value: Normal results on stress imaging tests (particularly perfusion scans) indicate such a low likelihood of significant CAD that coronary angiography is usually not indicated 1

3. Specific ECG considerations: Left bundle branch block or paced ventricular rhythm significantly reduces the accuracy of exercise testing, making pharmacologic imaging the preferred approach 1

4. Post-test risk assessment: While the Duke treadmill score has been traditionally used, newer nomogram models incorporating additional variables (age, sex, risk factors, heart rate recovery) provide better discrimination and calibration for mortality prediction 4

5. Low-risk patients: In patients deemed low-risk after observation (no recurrent chest pain, normal ECG, negative troponin), a standard exercise test can be used to confirm or establish CAD diagnosis before discharge 1

6. Avoid unnecessary testing: Stress testing (exercise or pharmacologic) is not recommended for patients with severe comorbidities that limit life expectancy or prevent revascularization 1