Coronary Complications of Kawasaki Disease: Novel Diagnosis Based on Z-score and Absolute Dimension

Kawasaki Disease or KD (also known as mucocutaneous lymph node syndrome) is an acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. Regarding serious coronary complications of the disease, the coronary effects and consequences of the disease in KD diagnosed children were investigated at Ayatollah Mousavi Hospital of Zanjan during 2013 to 2017.

This is a cross-sectional study in which 40 diagnosed cases of KD were evaluated from 2013 to 2017. At the time of diagnosis and 2 to 4 years later, the necessary measures were taken to check cardiovascular complications. After documenting informed consent, the patients underwent follow up echocardiography and electrocardiography. The data analysis was performed by statistical software, SPSS-18.

Totally,21 patients participated in the follow up. The results were analyzed and compared based on coronary artery dimension and Z-score reference values. Next, left coronary artery size was calculated in primary echocardiography based on Z-score in terms of body surface area. In primary echocardiography, Left Coronary Artery (LCA) size was within the reference range in 36 patients (90%) and abnormalities were observed in 4 patients (10%). In the follow up echocardiography, 21 patients revisited (2 of the 4 patients with abnormal findings) and all of them were reported to be within the reference range (p=0.02). Regarding Right Coronary Artery (RCA), findings from primary echocardiography were normal in 38 patients (95%) and abnormal in 2 patients (5%),  and based on follow up echocardiography, RCA sizes of all patients were in reference range (p=0.15).Interestingly, 2 patients were within the normal range based on coronary artery dimension, but were included in the dilation range using the Z-score; also, 2 patients who were in the dilated coronary artery range measured by the coronary artery dimension criterion, were included in the normal range by the Z-score.

To prevent missed diagnosis and further complications, it is recommended to use standard Z-score based on body surface area to diagnose coronary artery aneurysm in addition to merely measuring the diameter of the vessels.