Change in cardiac geometry and function in CKD children during strict BP control: a randomized study

Abstract

Background and objectives: Left ventricular hypertrophy (LVH) and abnormal systolic function are present in a high proportion of children with CKD. This study evaluated changes in left ventricular (LV) geometry and systolic function in children with mild to moderate CKD as an ancillary project of the Effect of Strict Blood Pressure Control and ACE Inhibition on Progression of Chronic Renal Failure in Pediatric Patients trial.

Design, setting, participants, & measurements: Echocardiograms and ambulatory BP monitoring were performed at baseline and at 1- or 2-year follow-up in 84 patients with CKD and 24-hour mean BP above the 50th percentile and/or receiving fixed high-dose angiotensin converting enzyme inhibition and randomized to conventional or intensified BP control.

Results: LVH prevalence decreased from 38% to 25% (P<0.05). Changes in LV mass index (LVMI) were restricted to patients with LVH at baseline (-7.9 g/m(2.7); P<0.02). Changes in LVMI were independent of randomization, reduction in BP, hemoglobin, and estimated GFR. A significant increase in midwall fractional shortening was observed in the total cohort (P<0.05), and was greater in the intensified group compared with the conventional BP control group (12%±1.9% versus 8%±1.5%; P=0.05). In multivariate analysis, improvement in myocardial function was associated with reduction in BP (r=-0.4; P<0.05), independently of LVMI reduction.

Conclusions: In children with CKD, angiotensin converting enzyme inhibition with improved BP control, LVH regression, and improved systolic function was observed within 12 months. Lowering BP to the low-normal range led to a slightly more marked improvement in myocardial function but not in LVMI.

Figure 1.

Reduction in 24-hour MAP SDS during the study period, according to randomization class. Significant reduction in BP was observed on mean 24-hour MAP at 12 months (P<0.001 versus baseline) and at 24 months (P<0.001 versus baseline). Conventional BP target aims for the 50th–95th BP percentile reference value of 24-hour MAP for height and sex. Intensified BP target aims for MAP below the 50th percentile BP reference value of 24-hour MAP for height and sex. MAP, mean arterial pressure; SDS, SD score.

Figure 2.

Reduction in LVMI during follow-up. Gray bars refer to mean change in LVMI between baseline and 12-month follow-up, and black bars refer to mean change in LVMI between baseline and 24-month follow-up (no differences could be observed in LVMI change according to follow-up time; all P>0.05). Bars are grouped according to no LVH at baseline (left bars), LVH at baseline (center bars), and overall study population (right bars). LVMI, left ventricular mass index; LVH, left ventricular hypertrophy.

Figure 3.

Reduction in the prevalence of LVH at follow-up, according to LVH definitions. Prevalence of LVH was slightly lower using a previously reported cutoff value (i.e., 38 g/m^2.7) compared with the most recent published data (P<0.05). At follow-up, LVH reduced significantly by both definitions (P<0.01). LVH, left ventricular hypertrophy.