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AAP Grand Rounds 18:64-65 (2007)
© 2007 American Academy of Pediatrics
McCrindle et al, from the University of Toronto, sought to assess whether children with a history of Kawasaki disease (KD) have increased risk factors and abnormalities suggestive of early atherosclerosis.
Patients between the ages of 10 and 20 years were selected from a database of all patients with KD seen at the Hospital for Sick Children between 1982 and 1998. These patients were randomly sampled from three groups based on current coronary artery involvement. Healthy control subjects of similar age were concurrently recruited from community groups. The medical records of the patients with KD were reviewed to determine characteristics of the acute KD episode, including initial coronary artery involvement, disease management, and current cardiovascular findings.
Atherosclerosis risk factors included recent and past medical history, smoking and smoke exposure, medication use, and family history. All participants underwent physical examinations and laboratory investigations. Brachial artery reactivity (BAR) in response to flow mediated dilation (FMD) and nitroglycerin was assessed using vascular ultrasonography
A total of 52 patients with KD were enrolled. Two-thirds were male. The mean age at time of KD episode was four years, with 96% having typical KD. Treatment included aspirin for 92% and intravenous gamma globulin for 64%. Coronary artery involvement at the time of KD episode included aneurysms in 37%, ectasia only in 16%, and no involvement in 47%. The mean time between the KD episode and the time of the study was 11.2 ± 3.7 years.
Coronary artery involvement at the time of the study revealed no involvement in 30 patients, regressed aneurysms in 16, and persistent aneurysms in six. KD patients and the 60 controls were similar with regard to most demographic features and atherosclerosis risk factors, but there was a tendency for the KD group to spend more time in sedentary pursuits, and a greater proportion of controls had obese mothers and hyperlipidemic fathers. As compared to controls, KD patients had higher mean hemoglobin A1c, lower mean apolipoprotein A1, and lower mean blood pressures. BAR did not differ significantly between KD and control subjects.
Among patients with a history of KD, age of the patient, sex, number of days of fever, number of diagnostic criteria, laboratory features, treatment with intravenous gamma globulin or aspirin, and BAR response to endothelium-dependent FMD were not significantly related to coronary artery involvement category. The authors conclude that for patients who have had KD, the degree of coronary artery involvement does not appear to be significantly associated with systemic endothelial function, even after adjustment for atherosclerosis risk factors. Systemic endothelial dysfunction does not appear to be present after KD.
Dalla Pozza et al, from Ludwig-Maximilians-University in Munich, Germany, sought to identify risk factors for atherosclerosis and systemic hypertension among patients with a history of KD. Children and adolescents with a history of admission to a tertiary care facility for KD and seen in a KD follow-up clinic were enrolled.
The control group consisted of friends of children with KD and children presenting for cardiac evaluation at the same facility. A family history of coronary artery disease and stroke was determined by questionnaire. All participants underwent physical and laboratory examinations. Common carotid artery intima-media thickness (IMT), a marker of subclinical atherosclerosis, was measured using ultrasonography. Baroreceptor sensitivity (BRS), which can be used to assess risk of developing hypertension, was determined using serial blood pressure and ECG determinations.
Twenty patients with a history of KD were compared with 28 controls. Patients had a mean age at the time of the study of 12.1 years, most were male (12/20 male), and all had typical KD treated with IVIG and aspirin. Fifteen of the 20 patients had coronary artery involvement. The mean time interval between the onset of the disease and the time of testing was 4.1 ± 3.6 years.
Demographic and biochemical features of the two groups were comparable. Absolute IMT was significantly higher in the KD group compared with the control group (0.449 mm vs 0.424 mm). Among KD patients, no direct correlation was identified between the IMT and factors characterizing the severity of KD (eg, ESR or white blood cell count). However, the IMT was significantly increased in those patients with involvement of the coronary arteries at the time of illness (0.459 mm in KD patients with coronary artery involvement vs 0.436 in those without).
There was no difference between patients and controls with regard to BRS. The authors acknowledge the limitations of the study design (eg, recruiting a high proportion of patients with a history of coronary involvement and its small sample size), but conclude that there are signs of subclinical atherosclerosis among KD patients with coronary artery involvement at the time of diagnosis. Following these patients with IMT testing may be helpful.
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Commentary by
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| Pediatric Cardiology, Children’s Memorial Hospital, Omaha, NE |
Successful acute management of KD has produced a large cohort of outwardly healthy children entering adulthood with a history of a diffuse transient vasculitis, which at the time produced variable degrees of coronary arterial involvement.1
We would like to be able to reassure them that their risks for coronary catastrophe disappeared with the rash and fever, and that they have no greater cause for worry than anyone else. But can we be sure that healed coronary vasculitis is "as good as new?" Perhaps KD has not been recognized long enough to allow us to see the increased risk of myocardial infarctions among middle-aged patients with a history of KD. Perhaps these young people need serious lifestyle and diet modifications, regular cardiac screening, and preemptive statins. Or perhaps not. We don’t know.
Because we are in doubt, what we really need is science. We need to bring the power of newer, noninvasive diagnostic methods to bear on the question of atherosclerotic risk as a result of KD. In that spirit, McCrindle et al2 chose to evaluate brachial artery reactivity (BAR) years after KD. BAR, a marker for systemic arterial endothelial dysfunction, was reassuringly normal, even in patients in whom coronary arterial involvement had been identified during the illness. Dalla Pozza et al3 chose to investigate a different marker for subclinical atherosclerosis in KD patients: the carotid intima-media-thickness (IMT). They found in their small sample that KD patients who had coronary artery involvement at the time of diagnosis had significant IMT abnormalities years later, to the point that they characterized the findings as subclinical atherosclerosis.
Even in light of these investigations we may not be much further along in solving the problem of what to say and do about potential development of atherosclerotic disease following KD. Do we convey encouragement based on a lack of pathologic BAR findings, or do we conclude that the abnormal carotid IMT means that we must sound the alarm for a large group of young people at risk for premature coronary disease? It appears that this calls for more science.
| Editors’ Note |
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