What are the indications for a pre-operative stress echocardiogram (echo) prior to orthopedic (ortho) surgery?

Indications for Pre-operative Stress Echocardiography Prior to Orthopedic Surgery

Pre-operative stress echocardiography is not routinely recommended prior to orthopedic surgery and should be limited to specific high-risk patients with poor functional capacity and multiple cardiac risk factors.

Risk Stratification Framework

The decision to perform pre-operative stress echocardiography should follow a stepwise approach based on:

1. Surgical Risk - Orthopedic surgery is classified as intermediate-risk surgery (1-5% risk of cardiac death or MI) 1
2. Patient Risk Factors - Clinical risk factors that increase perioperative cardiac risk
3. Functional Capacity - Patient's ability to perform daily activities

Clinical Risk Factors to Consider

• Major risk predictors 1:

  • Unstable coronary syndromes
  • Decompensated heart failure
  • Significant arrhythmias
  • Severe valvular disease

• Intermediate risk predictors 1:

  • Mild angina
  • Prior myocardial infarction
  • Compensated or prior heart failure
  • Diabetes mellitus
  • Renal insufficiency

• Minor risk predictors 1:

  • Advanced age
  • Abnormal ECG
  • Rhythm other than sinus
  • Low functional capacity
  • History of cerebrovascular accident
  • Uncontrolled hypertension

Specific Indications for Stress Echocardiography

Stress echocardiography before orthopedic surgery is indicated in the following scenarios:

1. Poor functional capacity (<4 METs) with 3 or more clinical risk factors 1

   • These patients should be considered for testing if it will change management

2. Patients with uninterpretable ECG (resting ST-segment depression ≥0.10 mV, complete left bundle-branch block, pre-excitation, or paced rhythm) who have intermediate risk predictors and poor functional capacity 1

3. Patients with known coronary artery disease, poor functional capacity, and high cardiac risk (>20% 10-year risk or presence of diabetes) 1

When NOT to Perform Stress Echocardiography

Stress echocardiography is not recommended in the following scenarios:

1. Low-risk patients (no clinical risk factors) undergoing orthopedic surgery 1

2. Patients with good functional capacity (≥4 METs) regardless of risk factors 1

3. Patients with 1-2 clinical risk factors and adequate functional capacity 1

4. Routine screening in all patients undergoing orthopedic surgery 1, 2

Contraindications to Stress Echocardiography

When considering stress echocardiography, be aware of these contraindications 1:

• Acute coronary syndrome
• Decompensated heart failure
• Severe/symptomatic aortic stenosis
• Uncontrolled arrhythmias
• Severe hypertension (≥200/110 mmHg)
• Acute aortic dissection
• Pericarditis/myocarditis
• Pulmonary embolism
• Severe pulmonary hypertension

For dobutamine stress echocardiography specifically:

• Critical aortic stenosis
• Hemodynamically significant left ventricular outflow tract obstruction

Clinical Implications

The 2024 AHA/ACC guidelines emphasize that stress testing is costly, may delay surgery, and has not been shown to improve clinical outcomes 1. The negative predictive value of stress echocardiography is high (typically >90%), but the positive predictive value for perioperative events is relatively low (0-37%) 1.

A positive stress echocardiogram showing moderate to large areas of ischemia (especially with ischemia in ≥5 segments) identifies patients at higher risk for perioperative cardiac events 1. However, routine testing in patients with coronary artery disease has not been associated with improved outcomes 2.

Key Takeaways

1. Risk stratification is essential - Use the clinical risk factors and functional capacity to determine the need for stress echocardiography
2. Avoid routine testing - Stress echocardiography should not be performed routinely prior to orthopedic surgery
3. Focus on high-risk patients - Reserve testing for patients with poor functional capacity and multiple risk factors
4. Consider alternative modalities when echocardiography is contraindicated or when specific clinical questions need to be addressed

By following these evidence-based guidelines, clinicians can appropriately select patients who will benefit from pre-operative stress echocardiography while avoiding unnecessary testing in low-risk individuals.