What surveillance is needed for a patient with Kawasaki disease and coronary artery dilation diagnosed in childhood?

Surveillance for Kawasaki Disease with Coronary Artery Dilation

Patients with Kawasaki disease and coronary artery dilation diagnosed in childhood require lifelong cardiac surveillance with the frequency determined by the severity of coronary involvement as measured by Z-scores. 1

Risk Stratification Based on Coronary Artery Z-Scores

The 2017 American Heart Association (AHA) guidelines recommend using Z-scores to classify coronary artery abnormalities and determine appropriate surveillance:

Z-Score Classification and Surveillance 1

• No involvement (Z-score <2): Least intensive follow-up
• Dilation only (Z-score 2 to <2.5): Intermediate follow-up
• Small aneurysm (Z-score ≥2.5 to <5): Regular surveillance
• Medium aneurysm (Z-score ≥5 to <10, absolute dimension <8 mm): Frequent surveillance
• Large or giant aneurysm (Z-score ≥10 or absolute dimension ≥8 mm): Most intensive surveillance

Surveillance Protocol

Initial Surveillance Period (First Year)

• Uncomplicated cases with normal coronary arteries:

  • Echocardiography at diagnosis, 1-2 weeks, and 4-6 weeks after treatment 1
  • If normal at 4-8 weeks, repeat echocardiography at 1 year is unlikely to reveal new abnormalities 1

• Cases with coronary artery abnormalities (Z-score >2.5):

  • More frequent echocardiography (at least twice per week) while coronaries are rapidly expanding 1
  • For giant aneurysms (Z-score ≥10), echocardiography at least weekly in first 45 days, then monthly until 3 months, then quarterly until 1 year 1

Long-Term Surveillance

For Small to Medium Aneurysms:

• Echocardiography every 3-6 months depending on stability of findings
• Assessment should include:
  • Coronary artery dimensions with Z-scores
  • Ventricular function
  • Valvular regurgitation
  • Aortic root dimensions 1

For Large or Giant Aneurysms:

• More frequent echocardiography (every 3 months)
• Additional imaging modalities are recommended:
  • Coronary angiography 6-12 months after onset of illness 1
  • Advanced imaging (CTA, CMRI) when echocardiography cannot adequately visualize distal coronary segments 1
  • Stress testing to evaluate for inducible myocardial ischemia 2

Comprehensive Assessment During Surveillance

Each echocardiographic evaluation should include:

• Coronary artery dimensions with Z-scores
• Left ventricular function (ejection fraction, shortening fraction)
• Regional wall motion abnormalities
• Valvular regurgitation (particularly mitral and aortic)
• Aortic root dimensions
• Presence/absence of pericardial effusion 1

Antithrombotic Therapy Based on Risk

Surveillance should be paired with appropriate antithrombotic therapy:

• All patients with persistent coronary artery disease: Long-term low-dose aspirin 1
• Giant aneurysms (≥8 mm): Low-dose aspirin plus warfarin (INR 2.0-3.0) 1
• Moderate-sized aneurysms: Aspirin plus a second antiplatelet agent 1

Important Considerations and Pitfalls

1. Visualization challenges: As children grow, echocardiographic visualization of coronary arteries becomes more difficult, necessitating advanced imaging techniques 1

2. Compliance with guidelines: Studies show poor compliance with recommended surveillance protocols, with only 4% of patients receiving all recommended follow-up studies 3

3. Risk of late complications: Even with aneurysm regression, patients remain at risk for stenosis and thrombosis, requiring ongoing surveillance 2

4. Transition to adult care: Establish a clear transition plan as pediatric patients move to adult cardiology care to ensure continuity of surveillance

5. Standardized approach: Use a standardized imaging protocol with Z-scores rather than absolute dimensions to account for patient growth 1, 2

By following these surveillance guidelines based on risk stratification, clinicians can optimize the detection of complications and improve long-term outcomes for patients with Kawasaki disease and coronary artery abnormalities.