Predicts high risk of coronary artery aneurysms by 8 weeks post-acute illness. Validated in diverse North American cohorts.
Predicts non-response to standard initial IVIG infusion. Score ≥ 4 (or ≥ 5) indicates high risk of IVIG resistance and CAA.
Complete KD: Fever ≥ 4–5 days + ≥ 4 of 5 principal clinical criteria:
Incomplete KD: Fever ≥ 5 days + 2–3 compatible features (or infant <6 mo with fever ≥7 days) + CRP ≥ 3.0 mg/dL or ESR ≥ 40 mm/hr PLUS either ≥ 3 supplemental lab criteria (anemia, platelets ≥450k after d7, albumin ≤3.0 g/dL, elevated ALT, WBC ≥15k, urine WBC ≥10/hpf) OR Positive Echocardiogram (LAD/RCA Z ≥ 2.5, CAA, or ≥3 features: decreased LV function, MR, pericardial effusion, Z 2.0–2.5).
| Risk Level | Description | Clinic & Echo Follow-up | Ischemia Stress Tests | Advanced Imaging (CTA/CMR) | Physical Activity |
|---|---|---|---|---|---|
| Level 1 | No CA involvement (Z < 2) | 1–2 wk (consider 4–6 wk if suboptimal or abnormal labs); discharge 4 wk to 1 yr | None | None | Full activity, promotion at every visit |
| Level 2 | Dilation only (Z 2 to <2.5) | 1–2 wk (visit at 6 wk if abnormal); 1 yr; discharge if normal. Assess q2–5y if persistent. | None | None | Full activity, promotion at every visit |
| Level 3.1 | Small CAA, persistent (Z 2.5 to <5) | 1 wk (weekly if enlarging until stable); 6 wk; 6 mo; 12 mo; then yearly | Every 3–5 years | Consider CTA at 1 yr baseline; q3–5y | Promotion counseling; restrict contact |
| Level 3.2 | Small CAA, regressed to normal/dilation | 1 wk; 6 wk; 1 yr; 5 yr (discharge if stress test & CTA normal) | Every 5 years | Consider CTA at 1 yr; if inducible ischemia | Full activity promotion |
| Level 4.1 | Medium CAA, persistent (Z 5 to <10, <8mm) | 1 wk (weekly until stable); 6 wk; 3 mo; 6 mo; 12 mo; then yearly | Every 2–5 years | Consider CTA at 1 yr baseline; q2–5y | Promotion; consider restrict contact; self-limit |
| Level 4.2 | Medium CAA, regressed to small | 1 wk; 6 wk; 6 mo; 12 mo; then yearly | Every 3–5 years | Consider CTA at 1 yr baseline; q3–5y | Promotion; restrict contact; self-limit |
| Level 4.3 | Medium CAA, regressed to normal/dilation | 1 wk; 6 wk; 6 mo; 12 mo; every 2 years | Every 4–5 years | Consider CTA at 1 yr; if inducible ischemia | Promotion; restrict contact; self-limit |
| Level 5.1 | Large/Giant CAA, persistent (Z ≥ 10 or ≥ 8mm) | 1 wk (weekly until stable); 6 wk; 3, 6, 9, 12 mo; then every 6–12 mo | Every 6–12 months | Baseline CTA within 2–6 mo; q1–5y or invasive angiography | Promotion; restrict contact; self-limit |
| Level 5.2 | Large/Giant CAA, regressed to medium | 1 wk (weekly until stable); 6 wk; 3, 6, 9, 12 mo; then every 6–12 mo | Every 2–5 years | Consider CTA at 1 yr baseline; q2–5y | Promotion; restrict contact; self-limit |
| Level 5.3 | Large/Giant CAA, regressed to small | 1 wk; 6 wk; 3, 6, 9, 12 mo; then yearly | Every 3–5 years | Consider CTA at 1 yr baseline; q3–5y | Promotion; restrict contact; self-limit |
| Level 5.4 | Large/Giant CAA, regressed to normal/dilation | 1 wk; 6 wk; 3, 6, 9, 12 mo; then every 1–2 years | Every 3–5 years | Consider CTA at 1 yr baseline; q3–5y | Promotion; restrict contact; self-limit |
| Medication | Mechanism / Class | Pediatric Dosing | Target Range / Monitoring | Key Clinical Points |
|---|---|---|---|---|
| Aspirin (ASA) | Antiplatelet (COX-1 inhibitor) |
Acute phase: 30–50 mg/kg/day divided q6h until afebrile 48–72h. Maintenance / Antiplatelet: 3–5 mg/kg once daily (max 81–325 mg/day). |
Clinical response. Platelet aggregation if resistance suspected. | Avoid NSAIDs (ibuprofen blocks antiplatelet effect). Defer live vaccines (MMR, Varicella) for 11 mo after IVIG. Inactivated flu vaccine recommended. |
| Clopidogrel | P2Y₁₂ ADP-receptor inhibitor | 0.2–1.0 mg/kg once daily PO (typical infant/child dose ~0.2 mg/kg/day; adult max 75 mg/day) | Clinical observation; monitor for bruising/bleeding. | Used in DAPT for Medium CAA (Level 4.1), ASA allergy/resistance, or in Triple Therapy for Giant CAA / thrombosis. |
| Warfarin | Vitamin K antagonist (factors II, VII, IX, X) | Load with 0.2 mg/kg/day, maintain with ~0.1 mg/kg/day titrated to INR. | Target INR: 2.0 – 3.0 (Daily until stable, then at least monthly). |
Indicated for Giant CAA (Level 5.1). Avoid in 1st trimester of pregnancy (teratogenic). Many food/drug interactions. |
| LMWH (Enoxaparin) | Factor Xa inhibitor |
<2 months: 1.5 mg/kg SC q12h >2 months: 1.0 mg/kg SC q12h |
Target anti-Factor Xa: 0.5 – 1.0 U/mL (drawn 4–6 h post-dose). | Preferred in infants & acute evolving aneurysms. Monitor antithrombin III if target anti-Xa not reached. |
| DOACs (Direct Oral Anticoagulants) AHA 2024 Update |
Direct Factor Xa / Thrombin inhibitors (Apixaban, Edoxaban) |
Apixaban: Weight-based twice daily (SAXOPHONE trial) Edoxaban: Weight-based once daily (ENNOBLE-ATE trial) |
Infrequent monitoring; no routine INR testing required. | 2024 AHA Update notes DOACs provide a convenient and safe alternative to Warfarin/LMWH with fewer dietary/drug interactions. Reversal agents available. |
| Statins (Atorvastatin) | HMG-CoA reductase inhibitor | 0.125 to 0.75 mg/kg/day PO (evaluated in children ≥2 yrs with CAA) | Lipid profile, liver enzymes (ALT/AST), CPK. | Pleiotropic anti-inflammatory & endothelial stabilization benefits for persistent/regressed CAA (Level 3–5). Avoid concurrent cyclosporine (CYP3A4). |
| β-Blockers | Cardioselective β-blockade | Carvedilol, Metoprolol succinate, or Bisoprolol | Heart rate & blood pressure. | May be considered in large/giant aneurysms (Level 5) to reduce myocardial oxygen demand and wall stress. |
Peak MI risk occurs in the first 2–3 months in large/giant CAA. Presenting symptoms in infants include irritability, unexplained crying, pallor, and diaphoresis; in older children chest/abdominal pain and vomiting.
| Patient ID / Name: — | Age: — | Sex: — |
| Weight: — kg | Height: — cm | BSA (Haycock): — m² |
| Artery | Dimension (mm) | Z-Score | AHA Classification |
|---|---|---|---|
| LMCA (Left Main) | — | — | — |
| LAD (Left Anterior Descending) | — | — | — |
| LCx (Left Circumflex) | — | — | — |
| RCA (Right Coronary) | — | — | — |
| Son et al. 2019 Score (CAA Risk): — | Kobayashi Score (IVIG Resistance): — |