Kawasaki Disease Coronary Assessment
A 3-year-old boy has completed 5 days of fever to 39.6 °C with bilateral non-purulent conjunctival injection, cracked lips, a polymorphous rash, and swelling of both hands. C-reactive protein is 180 mg/L, erythrocyte sedimentation rate 92 mm/h, and platelets 620 × 10⁹/L. Kawasaki disease is diagnosed and intravenous immunoglobulin is planned. Which investigation is most appropriate to assess the coronary arteries, both now and during follow-up?
- A.Computed tomography coronary angiography
- B.Cardiac catheterisation with angiography
- C.Transthoracic echocardiographyCorrect
- D.Serum troponin and creatine kinase MB
Explanation
Transthoracic echocardiography is the imaging modality of choice for assessing the coronary arteries in Kawasaki disease. In young children the chest wall is thin and the proximal coronary arteries are well visualised, allowing measurement of the left main, left anterior descending and right coronary artery internal diameters, which are then converted to body-surface-area-adjusted Z scores. Echocardiography is non-invasive, requires no ionising radiation or contrast, can be repeated as often as needed, and also assesses ventricular function, valvular regurgitation and pericardial effusion. The standard schedule is a baseline study at diagnosis, then repeat imaging at 1 to 2 weeks and again at 4 to 6 weeks, with more frequent studies if aneurysms are detected or the patient is immunoglobulin-resistant. Cardiac catheterisation with angiography gives superb anatomical detail but is invasive, requires general anaesthesia in small children, delivers radiation and contrast, and carries procedural risk, so it is reserved for complex or giant aneurysms and for interventional planning. Computed tomography coronary angiography is a useful adjunct in older children with distal or giant aneurysms poorly seen on echocardiography, but it involves radiation and is not first-line. Cardiac enzymes reflect myocardial injury and give no information about coronary anatomy or aneurysm formation. Importantly, a normal initial echocardiogram never excludes Kawasaki disease or delays treatment.
Why each option
- A.
- Computed tomography angiography is an adjunct for distal or giant aneurysms in older children but involves ionising radiation and is not first-line.
- B.
- Cardiac catheterisation is invasive with anaesthetic, radiation and procedural risks, and is reserved for complex aneurysms or intervention.
- C.
- Correct. Transthoracic echocardiography is non-invasive, repeatable and excellent for visualising proximal coronary arteries in young children.
- D.
- Cardiac enzymes detect myocardial injury but provide no information about coronary artery dilatation or aneurysm.
Reference: AHA Scientific Statement: Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease, 2017
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