Background: Echocardiography (echo) is recommended in patients (pts) with KD at baseline, 2 wks, and 6 wks after fever onset to detect coronary artery (CA) abnormalities. However, echo imaging is expensive and in infants and toddlers often requires sedation, which is burdensome and carries some risk.
Objective: To assess the benefit of additional echo imaging in uncomplicated KD pts with normal CAs at baseline and 2 wks.
Methods: In this retrospective two-center study, eligibility criteria were: 1) admission and treatment at center for acute KD; 2) no significant congenital heart disease; 3) available echo measurements of both the right (R) CA and left anterior descending (LAD) at ≤ Day 10 (baseline), 2 (±1) wks and 6 (±3) wks; and 4) normal CAs = RCA and LAD z scores [zMax] ≤2.0 and no aneurysms.
Results: Of 2,600 pts treated for KD from 1976 - 2014, 457 had normal CAs at baseline and 2 wks and met other inclusion criteria. Of these, 57% were male; median age was 3.3 yrs [IQR 1.8 to 5.4 yrs]; 77% had complete KD; and 14% received IVIG retreatment. At 6 wks, 450 (98.5%) had normal CAs. Of the remaining 7 pts, zMax was 2.0-2.4 in 5 (1.1%); their z scores subsequently normalized at 1 yr. The zMax was 2.5-2.9 in 1 (0.2%) pt who remained on low dose aspirin until 6 mos, when ECHO normalized. The zMax was ≥3.0 in 1 pt (0.2%, 95% CI [0.0%, 1.2%]) with a dilated LAD, which was normal 3 wks later. Sensitivity analysis using zMax of <2.5 was similar (98.0% with nl CAs at 6 wks).
Conclusion: New CA abnormalities are rarely detected at 6 wks in KD pts with normal CAs at baseline and 2 wks. The 6 wk echo may be unnecessary for uncomplicated KD pts with normal CAs at baseline and 2 wks.
Figure - CA zMax shown as mean (+), median, 25th to 75th %tile.