What is the recommended imaging frequency and protocol for a small coronary artery aneurysm?

Imaging Protocol for Small Coronary Artery Aneurysms

For patients with small coronary artery aneurysms (3-6 mm), yearly echocardiography with ECG is recommended, along with stress tests with myocardial perfusion imaging every 2 years in patients ≥10 years old. 1

Imaging Frequency Based on Aneurysm Classification

Small Coronary Artery Aneurysms (3-6 mm or z-score 3-7)

• Annual follow-up with echocardiogram and ECG by a pediatric cardiologist 1
• Stress tests with myocardial perfusion imaging every 2 years for patients ≥10 years old 1
• Coronary angiography only if myocardial ischemia is demonstrated by stress tests with imaging 1

If Aneurysm Persists (Risk Level 3.1)

• Echocardiography at 6 months after diagnosis, then yearly 1
• Stress testing for inducible myocardial ischemia every 2-3 years 1

If Aneurysm Regresses to Normal or Dilation Only (Risk Level 3.2)

• Echocardiography assessment every 1-3 years (may omit echocardiography in some visits) 1
• Stress testing every 3-5 years 1

Imaging Modalities

Primary Imaging Modalities

• Echocardiography: The cornerstone for serial monitoring of coronary artery morphology 1

  • Should be performed with highest-frequency transducer possible for detailed evaluation 1
  • Multiple imaging planes required for optimal visualization of all major coronary segments 1

• Stress Testing Options:

  • Stress echocardiography 1
  • Stress electrocardiography 1
  • Stress with magnetic resonance perfusion imaging 1
  • Stress with nuclear medicine perfusion imaging 1

Advanced Imaging

• Coronary angiography: Indicated only if non-invasive tests suggest myocardial ischemia 1
• CT coronary angiography: Provides clear visualization of coronary lumen and can highlight intraluminal thrombi 2

Monitoring for Complications

• Monitor for thrombosis formation, especially during the first 45 days of illness when risk is highest 1
• Watch for signs of myocardial ischemia, which may be silent or present with nonspecific symptoms in young children 1
• Assess for regression of aneurysms, which occurs in approximately 50% of cases within 1-2 years 1

Special Considerations

• Sedation is frequently needed for children <3 years of age to obtain high-quality echocardiographic images 1
• Studies should be recorded in dynamic video or digital cine format to enable comparison with subsequent studies 1
• Measurements should be made from inner edge to inner edge and should exclude points of branching 1
• For patients receiving antiplatelet therapy, collision or high-impact sports should be avoided due to bleeding risk 1

Risk Stratification Impact on Imaging

• The frequency and type of imaging are directly related to the size and persistence of aneurysms 1
• Medium (4-8 mm) and large/giant (>8 mm) aneurysms require more frequent imaging 1
• If aneurysms regress in size, imaging frequency can be reduced accordingly 1

By following this imaging protocol, clinicians can effectively monitor for aneurysm progression, regression, or complications that may require intervention, ultimately improving patient outcomes related to morbidity and mortality.