When should a cardiac stress test be ordered?

When to Order a Cardiac Stress Test

Cardiac stress tests should be ordered for patients with suspected coronary artery disease (CAD) who are at intermediate risk, patients with acute chest pain who have been stabilized, and for prognostic assessment in patients with established CAD. 1

Indications for Cardiac Stress Testing

Suspected Coronary Artery Disease

• Standard exercise treadmill testing is the initial procedure of choice for patients with normal or near-normal resting ECG who can adequately exercise 2
• Stress testing should be performed in patients with chest pain who are at low to intermediate risk after initial evaluation shows no high-risk features (normal ECG, negative cardiac biomarkers) 1
• Testing should be performed within 72 hours of presentation for low-risk patients evaluated on an outpatient basis 1
• For patients evaluated in chest pain units or emergency departments, stress testing can be performed after 8-12 hours of observation if the patient remains pain-free with normal ECGs and cardiac biomarkers 1

Imaging vs. Non-Imaging Stress Tests

• Imaging modalities (echocardiography, nuclear imaging) should be added when patients have:
  • Resting ST-segment depression ≥0.10 mV
  • Left ventricular hypertrophy
  • Bundle-branch block or intraventricular conduction defect
  • Pre-excitation syndrome
  • Digoxin therapy
  • Paced rhythm 1
• Pharmacological stress testing with imaging is recommended when physical limitations prevent adequate exercise (arthritis, amputation, severe peripheral vascular disease, COPD, general debility) 1

After Acute Coronary Syndrome

• Submaximal exercise testing can be performed before discharge (around 4-6 days post-event) for prognostic assessment and activity prescription 1
• Symptom-limited exercise testing can be performed 14-21 days after discharge if a predischarge test was not done 1
• Late testing (3-6 weeks) is appropriate if the early exercise test was submaximal 1

Known CAD and Prior Revascularization

• Stress testing is useful for activity counseling and exercise training as part of cardiac rehabilitation in patients who have undergone coronary revascularization 1
• Stress testing is generally not appropriate for asymptomatic patients less than 2 years after percutaneous intervention or less than 5 years after coronary artery bypass grafting 3
• For patients with known CAD and new symptoms, stress testing can help determine if there is progression of disease or new obstructive lesions 1

Special Populations

Asymptomatic Individuals

• Evaluation of asymptomatic persons with diabetes mellitus who plan to start vigorous exercise 1
• Consider testing in asymptomatic men older than 45 years and women older than 55 years who:
  • Plan to start vigorous exercise (especially if sedentary)
  • Work in occupations where impairment might impact public safety
  • Are at high risk for CAD due to other diseases (peripheral vascular disease, chronic renal failure) 1

Cocaine Users

• Patients with cocaine-associated chest pain who are at low to intermediate risk can undergo stress testing after 9-12 hours of observation if they remain stable 1
• Stress testing can be performed at the time of observation or on an outpatient basis depending on cardiac risk factors and ongoing symptoms 1

Contraindications to Stress Testing

• Severe comorbidity likely to limit life expectancy and/or candidacy for revascularization 1
• Acute myocardial infarction patients with uncompensated heart failure, cardiac arrhythmia, or severe noncardiac conditions that limit exercise ability 1
• Patients already selected for cardiac catheterization (although stress imaging may still be useful to evaluate ischemia in borderline lesions) 1
• Routine screening of asymptomatic men or women without risk factors 1

Risk Stratification Value

• The Duke treadmill score provides excellent prognostic value for exercise stress testing 3
• Imaging is not necessary if patients can achieve more than 10 metabolic equivalents on exercise stress testing 3
• Exercise stress testing is not indicated before noncardiac surgeries in patients who can achieve 4 metabolic equivalents without symptoms 3

Common Pitfalls to Avoid

• Ordering stress tests in asymptomatic low-risk patients without risk factors (not recommended) 1
• Failing to use imaging when indicated in patients with baseline ECG abnormalities (leads to decreased accuracy) 1, 2
• Performing stress tests too early in patients with acute myocardial infarction who are not clinically stable 1
• Not recognizing that women may have more false positive results during reproductive years 4
• Failing to consider pharmacologic stress testing when patients cannot achieve adequate exercise levels 1