Carotid artery intima-media thickness measurements in the youth: reproducibility and technical considerations.

BACKGROUND: Carotid artery intima-media thickness (CIMT), a marker of atherosclerosis, is increased in youth at risk for future cardiovascular disease. Some pediatric studies have used CIMT as a primary outcome in clinical trials, yet data are limited on the standardization of methodology in children. The goal of this study was to evaluate reproducibility of CIMT measurements using two different measurement techniques. METHODS: Carotid artery ultrasound studies of children and adolescents obtained as a component of a research study in Kawasaki syndrome were retrospectively analyzed. The CIMTs of both common carotid arteries (CCAs) were measured by one of two sonographers at the time in the cardiac cycle when resolution subjectively was determined to be optimal (Opt-CIMT). These sonographers blindly remeasured a random sample of studies of their own and each other's, using the same method. Another observer made CIMT measurements using exclusively frames on the R wave (R-CIMT). A fourth observer independently measured a random sample of studies twice with the R-CIMT method. RESULTS: Carotid artery images from 184 subjects (mean age, 14.7 ± 2.2 years) were analyzed. The intraclass correlation coefficient for interobserver variability was 0.86 (95% confidence interval [CI], 0.69-0.94) compared with 0.85 (95% CI, 0.65-0.93) for the right and 0.86 (95% CI, 0.67-0.94) versus 0.95 (95% CI, 0.87-0.98) for the left CCA for Opt-CIMT and R-CIMT, respectively. R-CIMT was significantly thicker than Opt-CIMT (right CCA, 0.439 ± 0.030 vs 0.428 ± 0.024 mm, P < .001; left CCA, 0.446 ± 0.030 vs 0.434 ± 0.025 mm, P < .001). CONCLUSION: Pediatric CIMT measurements have excellent reproducibility when the same methodology is applied but vary significantly throughout the cardiac cycle. This report highlights the need to standardize CIMT measurements in the youth and supports the use of electrocardiographic timing, as recommended in adults, in pediatric longitudinal studies.

Vascular health in Kawasaki disease.

OBJECTIVES: The objective of our study was to compare the indices of vascular health in Kawasaki disease (KD) patients to those of control subjects. BACKGROUND: The literature on peripheral vascular health after KD is conflicting. METHODS: Subjects were patients 11 to 29 years of age with the onset of KD >12 months before the study visit (n = 203) and healthy control subjects (n = 50). We measured endothelial function (using the Endothelial Pulse Amplitude Testing index), intima-media thickness (IMT) of the right common carotid artery (RCCA) and the left common carotid artery (LCCA), and fasting lipid profile and C-reactive protein (CRP). KD patients were classified according to their worst-ever coronary artery (CA) status: group I, always normal CAs (n = 136, 67%); group II, CA z-scores ≥2 but <3 (n = 20, 10%); group III, CA aneurysm z-scores ≥3 but <8 mm (n = 40, 20%); and group IV, giant CA aneurysm, defined as ≥8 mm (n = 7, 3%). RESULTS: At a median of 11.6 years (range, 1.2 to 26 years) after KD onset, compared with controls, KD patients had a higher peak velocity in the LCCA (p = 0.04) and higher pulsatility index of both the RCCA and LCCA (p = 0.006 and p = 0.05, respectively). However, there were no differences in the Endo-PAT index or carotid IMT or stiffness. The mean IMT of the LCCA tended to differ across the KD subgroups and control group (p = 0.05), with a higher mean in group IV. Otherwise the KD subgroups and control group had similar vascular health indexes. CONCLUSIONS: In contrast to some earlier reports, our study of North American children and young adults demonstrated that KD patients whose maximum CA dimensions were either always normal or mildly ectatic have normal vascular health indexes, providing reassurance regarding peripheral vascular health in this population.

Echocardiographic predictors of mitral stenosis-related death or intervention in infants.

BACKGROUND: The purpose of this study is to identify independent echocardiographic predictors of mitral stenosis (MS)-related death or intervention in infants. Congenital MS is a rare and morphologically heterogeneous lesion with variable prognosis. Among patients diagnosed with MS in early infancy, echocardiographic factors associated with MS-related intervention or death have not been determined. METHODS AND RESULTS: The clinical and echocardiographic data of patients diagnosed with MS at age <6 months by echocardiography between 1986 and 2004 were reviewed. The primary outcome was a composite end point of either mitral valve (MV) intervention (catheter or surgery) or death related to MS. Multiple variables from the initial echocardiogram were analyzed for association with outcomes. Seventy-one patients (median age at diagnosis 63 days) fulfilled the inclusion criteria. Multivariate analysis identified higher initial MV mean inflow gradient (P = .009) and lower left ventricular (LV) diastolic length Z-score (P = .006) at presentation as predictors of intervention or death. Among patients with an initial MV inflow gradient < 2 mm Hg, none reached an end point, whereas, among patients with an initial mean gradient >/= 5.5 mm Hg, the risk of intervention or death was 85%. Among patients with a gradient > 2 and < 5.5 mm Hg, an end point was reached in 38%, and an LV diastolic length Z-score