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.
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.