On What Day of Illness Does the Dilatation of Coronary Arteries in Patients With Kawasaki Disease Begin?

BACKGROUND

In the present study we used echocardiography to investigate coronary artery diameter at the time of diagnosis of Kawasaki disease (KD), before the start of treatment.Methods and Results:Diameters of the right, left main, left anterior descending, and left circumflex coronary arteries were determined in 410 patients before KD treatment commenced. The maximum Z-score was considered to be the pretreatment, maximum coronary artery Z-score (preZmax). The cumulative probability of coronary arterial dilatation was analyzed using the Kaplan-Meier method. In the present study, 31 patients (7.6%) had a preZmax ≥3.0, 56 (13.7%) had a preZmax ≥2.5, and 96 (23.4%) had a preZmax ≥2.0. The cumulative probability of a preZmax ≥2.0 was >20% on Day 5 of illness, 40% on Day 7, and 70% on Day 10. The positive predictive value (PPV) of a preZmax of 2.0 was approximately 0.9 on Day 5 of illness.

CONCLUSIONS

The present study demonstrates that the coronary arteries may dilate before Day 5 of illness, and that the rate of dilatation increases gradually until Day 10. Because preZmax 2.0 has high PPV after Day 5 of illness, it is a useful marker of coronary artery dilatation in the early phase of KD.