Diastolic Function and Ambulatory Hypertension in Children With Chronic Kidney Disease

Diastolic dysfunction is one of the earliest cardiac abnormalities in patients with chronic kidney disease. We analyzed echocardiographic markers of left ventricular function from 786 children and adolescents (1658 person-visits) enrolled in the CKiD (Chronic Kidney Disease in Children) cohort, a large prospective observational study of children with chronic kidney disease. Primary outcome was early mitral inflow velocity-to-early mitral annular peak velocity (E/e′) ratio as a marker of left ventricular compliance. Abnormal diastolic function was defined as E/e′>8.0. Those with an abnormal E/e′ ratio were younger, had a lower estimated glomerular filtration rate and hemoglobin, and a higher prevalence of hypertension and left ventricular hypertrophy compared to children with a normal E/e′. In adjusted analysis, a higher E/e′ ratio was independently associated with ambulatory (sustained) hypertension (1.66 [95% CI, 1.15-2.42]). Other significant independent predictors were higher left ventricular mass index Z score, increased body mass index Z score, lower hemoglobin, higher phosphorus level, and younger age. Casual blood pressure was not significantly associated with higher E/e′. These data indicate that ambulatory blood pressure might better identify children with chronic kidney disease at risk for subclinical cardiac dysfunction than clinic blood pressure alone.