What are the indications for a stress test in patients with a history of cardiovascular disease, high risk factors such as hypertension (high blood pressure), hypercholesterolemia (high cholesterol), diabetes, or those who are overweight or obese, physically inactive, or have a family history of heart disease?

Indications for Stress Testing

Stress testing should be performed in symptomatic patients with suspected coronary artery disease who have an interpretable ECG and can exercise adequately, while asymptomatic patients generally do not require routine screening unless they have diabetes planning vigorous exercise or multiple high-risk features. 1

Primary Indications for Stress Testing

Symptomatic Patients

• Chest pain evaluation: Patients with suspected myocardial ischemia and chest pain represent the primary indication for stress testing 1, 2
• Unexplained dyspnea: Shortness of breath with exertion warrants stress testing, particularly when cardiac etiology is suspected 1, 3
• Syncope with exercise: Unexplained loss of consciousness during physical activity requires stress evaluation 1
• Palpitations: Exercise-induced arrhythmias can be assessed, though this indication carries lower mortality risk 3

Post-Acute Coronary Events

• After myocardial infarction: Submaximal testing before discharge or symptom-limited testing 2-3 weeks post-event for risk stratification 4
• Stable acute coronary syndrome: Intermediate- and low-risk patients should undergo testing when clinically stable 4
• Post-revascularization: Patients with prior coronary intervention require stress imaging rather than standard ECG testing 5

Asymptomatic High-Risk Populations (Class IIa-IIb)

Diabetes mellitus represents the strongest indication among asymptomatic patients:

• Diabetic patients ≥40 years planning vigorous exercise should undergo stress testing 1
• Consider stress myocardial perfusion imaging in diabetics with strong family history of CAD or CAC score ≥400 1

Multiple risk factors (Class IIb - weaker recommendation):

• Men >45 years or women >55 years with ≥2 risk factors (hypercholesterolemia >240 mg/dL, hypertension >140/90 mmHg, smoking, diabetes, family history of premature CAD in first-degree relative <60 years) 1
• Particularly justified when planning vigorous exercise after sedentary lifestyle 1
• Those in occupations affecting public safety 1

Pre-Operative Risk Assessment

• Patients with poor functional capacity (<4 METs) and elevated cardiovascular risk before noncardiac surgery 6
• Pharmacologic stress testing preferred for those unable to exercise adequately 7

Valvular Heart Disease

• Aortic regurgitation: Assessment of functional capacity and symptomatic responses in patients with equivocal symptoms 1
• Evaluation of transvalvular gradients during exercise when symptoms are disproportionate to resting severity 1

Contraindications to Routine Screening

Class III (Not Recommended):

• Routine screening of asymptomatic men or women without risk factors 1
• Asymptomatic patients with severe dyslipidemia alone (LDL >190 mg/dL) should receive statin therapy, not stress testing 2
• Low-risk asymptomatic adults (<6% 10-year ASCVD risk) 1

Test Selection Algorithm

Step 1: Assess Exercise Capacity and Baseline ECG

• Normal baseline ECG + able to exercise: Standard exercise ECG is first-line 6, 5
• Abnormal baseline ECG (LBBB, LVH, digoxin use, resting ST changes): Stress imaging required 6, 7
• Unable to exercise adequately: Pharmacologic stress testing 6, 7

Step 2: Choose Imaging Modality if Needed

• Exercise stress echocardiography: For patients who can exercise but have uninterpretable ECG; provides valve assessment 6
• Vasodilator nuclear imaging (regadenoson preferred): For patients unable to exercise without contraindications to vasodilators 6
• Dobutamine stress echo: For patients with contraindications to vasodilators or requiring valve assessment 6

Common Pitfalls to Avoid

Do not perform stress testing when:

• The baseline ECG is uninterpretable (LBBB, paced rhythm) without adding imaging modality 6
• Results will not change management decisions 1
• Patient has acute coronary syndrome, decompensated heart failure, severe aortic stenosis, uncontrolled arrhythmias, or severe hypertension (≥200/110 mmHg) 6

Critical distinction: The indication for testing significantly impacts prognosis - patients referred for dyspnea have 15% higher mortality than those with chest pain, particularly in established CAD 3. This underscores that dyspnea warrants serious evaluation, not dismissal as "non-cardiac."

Asymptomatic screening caveat: The DIAD trial demonstrated no mortality benefit from screening asymptomatic diabetics with stress MPI, though the study was underpowered 1. Therefore, even in diabetes, stress testing should focus on those planning vigorous exercise or with very high-risk features (CAC ≥400, strong family history) 1.