Echo-Doppler Assessment of Arterial Stiffness in Pediatric Patients with Kawasaki Disease

Abstract

There is growing evidence to suggest increased arterial stiffness in patients with a history of Kawasaki disease (KD). Pulse-wave velocity (PWV) is the most validated measure of arterial stiffness. The aim of this study was to determine if aortic PWV is increased in children with KD. This was a retrospective cohort study. The study cohort was composed of 42 patients with KD (mean age, 9.7 ± 2.0 years) and 44 age-matched control subjects. The primary measure was aortic PWV. Secondary measures included characteristic impedance (Zc), input impedance (Zi), elastic pressure-strain modulus (Ep), and β stiffness index and the following measures of left ventricular size and function: end-diastolic and end-systolic dimensions, wall thickness in diastole and systole, mass, shortening and ejection fractions, mean velocity of circumferential fiber shortening, and stress at peak systole. The appropriate measures were indexed to body surface area. The aortic stiffness and impedance indexes were derived using an echocardiography-Doppler method. Height, weight, body mass index, and body surface area were similar between the groups. PWV was higher in patients with KD compared with controls (495 vs 370 cm/sec, P = .0008). Zc, Ep, and β stiffness index were higher in patients with KD, but the difference was not statistically significant. Left ventricular dimensions were all within normal limits, with no differences between the groups. Patients with KD had lower stress at peak systole compared with controls (55 vs 64 g/cm(2), P = .01). There was a significant association between the length of time between the initial diagnosis and testing with PWV (r = 0.32, P = .04) and Zi (r = -0.38, P = .01) in patients with KD. There was no significant association between the arterial stiffness indexes (PWV, Zi, Zc, Ep, and β stiffness index) and length of fever, age at KD diagnosis, or heart rate. Logistic regression analysis revealed no association between coronary artery lesion classification and length of fever, day of illness at first treatment, age at KD diagnosis, or any of the arterial stiffness indexes. In the control group, there were significant associations between age and heart rate (r = -0.48, P = .001), Zi (r = -0.55, P < .0001), Zc (r = -0.66, P < .0001), and β stiffness index (r = -0.31, P = .04). There was an association between heart rate and Zc (r = 0.44, P = .003) but no association between heart rate and PWV, Zi, Ep, or β stiffness index. Arterial stiffness was increased in children with KD. There was no association between acute-phase KD coronary involvement and PWV. This implies that patients with KD may be at increased cardiovascular risk in the future.