Low agreement between cardiologists diagnosing left ventricular hypertrophy in children with end-stage renal disease

BACKGROUND Monitoring of the appearance of left ventricular hypertrophy (LVH) by echocardiography is currently recommended for in the management of children with End-stage renal disease (ESRD). In order to investigate the validity of this method in ESRD children, we assessed the intra- and inter-observer reproducibility of the diagnosis LVH. METHODS Echocardiographic measurements in 92 children (0-18 years) with ESRD, made by original analysists, were reassessed offline, twice, by 3 independent observers. Smallest detectable changes (SDC) were calculated for continuous measurements of diastolic interventricular septum (IVSd), Left ventricle posterior wall thickness (LVPWd), Left ventricle end-diastolic diameter (LVEDd), and Left ventricle mass index (LVMI). Cohen's kappa was calculated to assess the reproducibility of LVH defined in two different ways. LVH(WT) was defined as Z-value of IVSd and/or LVPWd>2 and LVH(MI) was defined as LVMI> 103 g/m² for boys and >84 g/m² for girls. RESULTS The intra-observer SDCs ranged from 1.6 to 1.7 mm, 2.0 to 2.6 mm and 17.7 to 30.5 g/m² for IVSd, LVPWd and LVMI, respectively. The inter-observer SDCs were 2.6 mm, 2.9 mm and 24.6 g/m² for IVSd, LVPWd and LVMI, respectively. Depending on the observer, the prevalence of LVH(WT) and LVH(MI) ranged from 2 to 30% and from 8 to 25%, respectively. Kappas ranged from 0.4 to 1.0 and from 0.1 to 0.5, for intra-and inter- observer reproducibility, respectively. CONCLUSIONS Changes in diastolic wall thickness of less than 1.6 mm or LVMI less than 17.7 g/m² cannot be distinguished from measurement error in individual children, even when measured by the same observer. This limits the use of echocardiography to detect changes in wall thickness in children with ESRD in routine practice.