SAT-091 NOCTURNAL HYPERTENSION ON LONGITUDINAL AMBULATORY BLOOD PRESSURE MONITORING AND LEFT VENTRICULAR HYPERTROPHY IN PEDIATRIC RENAL TRANSPLANT RECIPIENTS

Abstract

Hypertension (HTN) after renal transplantation is known to be associated with cardiovascular morbidity. Indian children with chronic kidney disease (prior to transplantation) have a 3 times higher prevalence of LVH1 compared to western counterparts2. The aims of this observational study in pediatric kidney transplant recipients were to describe the prevalence of masked HTN and LVH, the association between ABPM measurements and left ventricular mass index (LVMI ) and to determine the longitudinal changes in ambulatory blood pressure monitoring (ABPM). ABPM and auscultatory clinic BP were performed in children (2015- 2018), ≥ 3 months post transplant with a stable functioning renal allograft at baseline and repeated in 6-12 months. Mean daytime and sleep ambulatory BPs were calculated. Nocturnal dip (mean sleep BP vs. mean daytime BP) <10% was defined as blunted. Clinic and ABPM mean BPs were indexed to the 95th percentile (HTN present if BP index ≥ 1). ECHO data from a single timepoint performed within 6 months of ABPM was used to calculate LVMI (LVH present if > 95th percentile for age/sex). Masked HTN was defined as clinic BP index <1 and ABPM SBP or DBP index ≥ 1. Isolated nocturnal hypertension was diagnosed if daytime BP indices were <1 but sleep BP indices were ≥ 1. Linear Regression determined the association between LVMI and ABPM indices. Baseline Data: 30 children were included (14 boys, 28 living donor allografts, age 13.2 ±3 yrs, eGFR = 75±32 ml/min/1.73m2, median 18mths post transplant). Masked HTN was present in 16/30 (53%), [Fig 1]; all with masked HTN were treated with increased dose and/or number of BP medications. Clinic BP failed to diagnose 65% of patients with HTN. Isolated nocturnal HTN occurred in 13/25 (52%) of patients with HTN. Sleep SBP and DBP indices were higher than daytime BPs (p < 0.001 for each). Blunted nocturnal dip was present in 80%. LVH and LVMI: 12/21 patients (57%) with echoes had LVH; all with LVH had HTN by ABPM. Elevated sleep SBP and DBP indices as well as sleep BP loads (p < 0.05 for each) were associated with elevated LVMI. Follow-up Data: 18 had follow-up ABPM [Table 1]. Overall, BPM indices (not clinic BPs) decreased on follow-up (all p < 0.05) but sleep BPs remained higher than daytime. Table 1: Ambulatory BP Values on Initial ABPM and Follow UP Prevalence of masked HTN, isolated nocturnal HTN and blunted nocturnal dip was high in this study of children with kidney transplants. Nocturnal BP predicted LVMI. Clinical treatment based on ABPM was associated with improvement in BP, but nocturnal hypertension was persistent. This data confirms the importance of proactive ABPM monitoring of children with kidney transplants as hypertension is not satisfactorily assessed by office evaluation.