Introduction: While the risk is reduced, patients may develop coronary artery aneurysms (CAA) after Kawasaki disease (KD) despite receiving intravenous immunoglobulin (IVIG) within 10 days of onset of symptoms. Risk factors for CAA may differ compared to those patients with delayed or no treatment.
Methods: Patients diagnosed with KD between 1990 and 2013 were included. Patients with maximum coronary artery z-scores >5 were classified as having CAA. Separate multivariable regression models were used to determine factors associated with CAA for those with vs. without prompt treatment.
Results: Of 1,358 patients included, 83% were treated with IVIG within 10 days and 5.4% developed CAA. Patients who had delayed (>10 days) or no IVIG treatment were at increased odds of developing CAA (OR: 3.1, p<0.001). From 1990-2013, the proportion of patients treated promptly increased (OR: 1.05/year, p=0.006) while the total duration of fever decreased (EST: -0.10 (0.03) days/year, p=0.001). These trends were associated with a shift such that a greater proportion of the patients who developed CAA actually had been treated promptly (from <25% in 1990 to >70% in 2013, OR: 1.1/year, p=0.01). For patients with prompt treatment with IVIG, factors associated with increased odds of CAA were: longer duration of fever prior to treatment (OR: 1.2/day, p=0.04), age <1 year old (OR 3.9, p=0.001), higher pre-IVIG white blood cell count (OR: 1.05/x109/L, p=0.007), lower hemoglobin (OR: 1.4/g/L, p=0.004) and non-response to the initial IVIG treatment (OR: 2.5, p<0.001). For patients with delayed or no treatment, factors associated with increased odds of CAA were: males (OR: 5.4, p=0.009), age <1 year old (OR: 29.9, p<0.001), lower red blood cell count (OR: 2.5/-0.5 x1012/L, p=0.01) and higher platelet count at diagnosis (OR: 1.4/100x1012/L, p=0.001). Additionally, delayed treatment with IVIG did not reduce the risk of CAA (OR: 1.9, p=0.28), and total duration of fever was not associated with CAA for this group (OR: 1.04/day, p=0.16). .
Conclusions: Factors associated with the development of CAA are generally similar for those treated promptly vs. those with delayed or no treatment. For those with delayed diagnosis, treatment with IVIG does not appear to be effective to prevent CAA.