White Coat Hypertension Persistence in Children and Adolescents: The Pediatric Nephrology Research Consortium Study.

OBJECTIVES: To determine whether youth with white coat hypertension on initial ambulatory blood pressure monitoring (ABPM) continue to demonstrate the same pattern on repeat ABPM. STUDY DESIGN: Retrospective longitudinal cohort study of patients referred for high blood pressure (BP) and diagnosed with white coat hypertension by ABPM who had follow-up ABPM 0.5-4.6 years later at 11 centers in the Pediatric Nephrology Research Consortium. We classified ABPM phenotype using the American Heart Association guidelines. At baseline, we classified those with hypertensive BP in the clinic as "stable white coat hypertension," and those with normal BP as "intermittent white coat hypertension." We used multivariable generalized linear mixed effect models to estimate the association of baseline characteristics with abnormal ABPM phenotype progression. RESULTS: Eighty-nine patients met the inclusion criteria (median age, 13.9 years; 78% male). Median interval time between ABPM measurements was 14 months. On follow-up ABPM, 61% progressed to an abnormal ABPM phenotype (23% ambulatory hypertension, 38% ambulatory prehypertension). Individuals age 12-17 years and those with stable white coat hypertension had greater proportions progressing to either prehypertension or ambulatory hypertension. In the multivariable models, baseline wake systolic BP index ≥0.9 was significantly associated with higher odds of progressing to ambulatory hypertension (OR 3.07, 95% CI 1.02-9.23). CONCLUSIONS: The majority of the patients with white coat hypertension progressed to an abnormal ABPM phenotype. This study supports the 2017 American Academy of Pediatrics Clinical Practice Guideline's recommendation for follow-up of ABPM in patients with white coat hypertension.

Reclassification of adolescent hypertension by ambulatory blood pressure monitoring using adult norms and association with left ventricular hypertrophy.

2017 pediatric blood pressure (BP) guidelines applied adult BP norms to define clinic hypertension (HTN) in patients ≥ 13 years. 2014 pediatric ambulatory BP monitor (ABPM) guidelines recommend age- and sex-specific percentile norms for patients < 18 years. The authors evaluated reclassification of HTN when applying adult ABPM norms in patients ≥ 13 years and assessed the association of left ventricular hypertrophy (LVH) with HTN. Charts of patients 13-17 years with ABPM 9/2018-5/2019 were reviewed for sex, age, height, weight, BP medication, ABPM results, and left ventricular mass index (LVMI). American Heart Association 2005 (AHA 2005), AHA 2017 (AHA 2017), and European Society of Hypertension 2018 (ESH 2018) guidelines for adult ABPM were compared with 2014 AHA pediatric norms (pABPM). HTN was defined by each guideline using only ABPM. ABPM and clinic BP were used to classify white coat hypertension (WCH) and masked hypertension (MH). LVH was defined as LVMI > 51 g/m2.7 . 272 patients had adequate ABPM. 124 patients also had echocardiogram. All adult norms resulted in significant reclassification of HTN. LVMI correlated significantly with systolic BP only. The odds of a patient with HTN having LVH was significant using AHA 2005 (OR: 8.75 [2.1, 36.4], p = .03) and ESH 2018 (OR: 4.94 [1, 24.3], p = .002). Significant reclassification of HTN occurs with all adult norms. HTN is significantly associated with LVH using AHA 2005 and ESH 2018. Applying pediatric norms for ABPM while using adult norms for clinic BP causes confusion. Guideline selection should balance misdiagnosis with over-diagnosis.

Diagnostic sensitivity and specificity of CT angiography for renal artery stenosis in children.

BACKGROUND: Children with suspected renal artery stenosis (RAS) are screened with renal Doppler ultrasonography or computed tomography (CT) angiography/magnetic resonance (MR) angiography depending on institutional preference. CT angiography produces images with superior resolution, allowing higher quality multiplanar two-dimensional reformats and three-dimensional reconstructions. However, there is a paucity of data in the literature regarding the utility and diagnostic performance of renal CT angiography in pediatric RAS. OBJECTIVE: The objective of this study is to retrospectively review our experience with renal CT angiography in the diagnosis of pediatric RAS relative to digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: All patients 0-18 years of age who underwent CT angiography for evaluation of RAS as a cause of hypertension between January 2012 and May 2019 were identified for the study. A total of 131 patients were identified, 23 of whom had DSA correlation. RESULTS: Twenty-three patients (17 boys, 6 girls) with a mean age of 6 years 3 months (range: 3 months to 14 years 7 months) were included in this study. Of the 59 renal arteries studied by DSA, 22 were abnormal on CT angiography and 20 were abnormal on DSA. Of the 59 renal arteries, CT angiography was true positive in 18 and true negative in 35. The sensitivity and specificity of CT angiography for RAS diagnosis were 90.0% and 89.7%, respectively. CT angiography identified all cases of main RAS. CONCLUSION: Renal CT angiography has a high sensitivity and specificity for pediatric RAS diagnosis in patients referred for DSA.

Hyperuricosuria, hematuria, and novel bladder images with IgA nephropathy.

Episodic (recurrent) macroscopic hematuria in patients with IgA nephropathy is usually associated with a benign prognosis, although some patients experience a transient fall in glomerular filtration rate during the episodes. We present a 15-year-old girl with mild IgA nephropathy who had multiple episodes of macroscopic hematuria associated with severe but transient decreases in estimated glomerular filtration rate, low levels of serum uric acid, and marked increases in fractional excretion of uric acid. Ultrasound studies showed marked inflammatory changes in the bladder, especially involving the trigone. Cystoscopic findings were consistent with these changes. We hypothesize that the macroscopic hematuria may have resulted, at least in part, from hyperuricosuria causing acute irritation of the bladder mucosa in the trigone area.

Interventions in children with renovascular hypertension: A 27-year retrospective single-center experience.

BACKGROUND: Renovascular hypertension (RVH) can be caused by renal artery stenosis (RAS) and/or middle aortic syndrome (MAS). METHODS: Patients who received surgical or transcatheter treatment for RVH between 1/1991 and 11/2017 were retrospectively reviewed using age = adjusted blood pressure ratio (BPR). RESULTS: Fifty-three patients diagnosed with RVH at a median age of 4.5 (0-18) years were included. Vascular involvement ranged from MAS with RAS (20), RAS only (32), and MAS only (1). The first intervention was transcatheter in 47 patients (transcatheter group: angioplasty = 41, stenting = 5, and thrombectomy = 1), and surgical in 6 patients (surgical group), occurring at a median age of 6.2 (0.1-19.6) years. There was a change toward transcatheter interventions as the first procedure over the study period. First reinterventions in the transcatheter group (27 lesions in 18 patients) were repeat transcatheter (in 20 lesions) and surgery (7 lesions) at a median of 92 (2-2555) days; in the surgical group (5 lesions in 4 patients) first reinterventions were transcatheter (4 lesions) and repeat surgery (1) at a median of 2.2 (1.1-12.0) years. A total of 136 transcatheter and 30 surgical discrete interventions were performed. There was a significant decline in antihypertensive medications and BPR at 4-6 months after the first intervention and on last follow-up in patients initially treated by transcatheter means while the decline was not significant in the surgical group (limited by small sample size). Complications were significantly more common in the surgical group (P < .01), 11/27 (41%) vs 10/136 (7.4%). Four patients died (2 from each group): 2 with congenital renal artery atresia and MAS, 2 with MAS and RAS. The median follow-up interval was 3.6 (0.1-35.2) years. CONCLUSION: Pediatric patients with RVH treated with transcatheter means as the first intervention had significant improvement in BPR, as well as decline in antihypertensive medications and were less likely to suffer major complications.

Rasburicase for hyperuricemia in hemolytic uremic syndrome.

BACKGROUND: Acute kidney injury (AKI) with elevated serum uric acid (UA) levels has been reported in patients with hemolytic uremic syndrome (HUS). AKI is thought to result from tubular obstruction by UA crystals. Inducing a diuresis may ameliorate the oligoanuria in such patients. We describe a child with HUS in whom reducing UA with fluids and rasburicase appeared to accelerate the recovery of renal function. CASE-DIAGNOSIS/TREATMENT: A 9-month-old Caucasian male infant presented with 6 days of diarrhea, 3 days of vomiting, and 24 h of oliguria. On admission, hemoglobin was 8.3 g/dL, platelet count 36,000/L, blood urea nitrogen 73 mg/dL, and serum creatinine (SCr) 2.7 mg/dL. Diarrhea-associated HUS was diagnosed. The day after admission, SCr was 2.9 mg/dL and UA 12.3 mg/dL. On hospital day 2, he received a dose of intravenous rasburicase 0.18 mg/kg, and less than 12 h later, the UA had fallen to 0.3 mg/dL. The SCr level also started to fall, and urine output progressively increased without the use of diuretics. Renal function continued to improve, and the UA level remained normal despite ongoing hemolysis requiring a second red blood cell transfusion on hospital day 5. The patient was discharged on hospital day 7 in good physical condition. Two months later, he was in good health, with a SCr level of 0.2 mg/dL and UA of 4.2 mg/dL. CONCLUSIONS: We postulate that aggressive management of the high serum UA level with rasburicase and fluid hydration accelerated the recovery of our patient. Further studies are needed to determine the role of rasburicase in the treatment of hyperuricemia in patients with HUS.

Development of hypertension in adolescents with pre-hypertension.

OBJECTIVE: To evaluate the risk for developing incident hypertension (HTN) in adolescents with pre-hypertension. STUDY DESIGN: A secondary analysis of students participating in multiple school-based blood pressure (BP) screens from 2000 to 2007 was completed. At each screen, height, weight, and 2 to 4 BPs were measured on as many as 3 occasions when BP remained ≥ 95th percentile. Students with confirmed HTN at their initial screen were excluded, and incident HTN was defined as having a BP ≥ 95th percentile at all 3 visits of a later screen. Incidence rates (IR) and hazard ratios (HR) were calculated by using Cox Proportional models. RESULTS: Of 1006 students, HTN developed in 11 (IR 0.5%/year) in a mean of 2.1 years of observation. IRs were higher in "at-risk" students (pre-hypertensive or hypertensive with follow-up BP <95th percentile), 1.4%/year (HR, 4.89; 1.48-16.19) and students with a BP ≥ 90th percentile at 3 baseline visits, 6.6%/year HR 24.33 (5.68-104.29)]. Although not significant, students with pre-hypertension by the 2004 Task Force definition also had an increased IR of 1.1%/year (HR, 2.98; 0.77-11.56)]. CONCLUSION: Elevated BP increases the risk for the development of HTN during adolescence. Effective strategies for preventing HTN in at-risk adolescents are needed.

Prevalence of persistent prehypertension in adolescents.

OBJECTIVE: To measure the prevalence of persistent prehypertension in adolescents. STUDY DESIGN: We collected demographic and anthropometric data and 4 oscillometric blood pressure (BP) measurements on 1020 students. The mean of the second, third, and fourth BP measurements determined each student's BP status per visit, with up to 3 total visits. Final BP status was classified as normal (BP <90th percentile and 120/80 mm Hg at the first visit), variable (BP ≥ 90th percentile or 120/80 mm Hg at the first visit and subsequently normal), abnormal (BP ≥ 90th percentile or 120/80 mm Hg at 3 visits but not hypertensive), or hypertensive (BP ≥ 95th percentile at 3 visits). The abnormal group included those with persistent prehypertension (BP ≥ 90th percentile or 120/80 mm Hg and <95th percentile on 3 visits). Statistical analysis allowed for comparison of groups and identification of characteristics associated with final BP classification. RESULTS: Of 1010 students analyzed, 71.1% were classified as normal, 15.0% as variable, 11.5% as abnormal, and 2.5% as hypertensive. The prevalence of persistent prehypertension was 4.0%. Obesity similarly affected the odds for variable BP (OR, 3.9; 95% CI, 2.5-6.0) and abnormal BP (OR, 3.4; 95% CI, 2.0-5.9), and dramatically increased the odds for hypertension (OR, 38.4; 95% CI, 9.4-156.6). CONCLUSION: Almost 30% of the students had at least one elevated BP measurement significantly influenced by obesity. Treating obesity may be essential to preventing prehypertension and/or hypertension.

Ambulatory blood pressure monitoring: a versatile tool for evaluating and managing hypertension in children.

In recent years, pediatric practitioners have increasingly used ambulatory blood pressure (ABP) monitoring for evaluating blood pressure (BP) abnormalities in children. ABP monitoring in adults is superior to casual BP measurements for predicting cardiovascular morbidity and mortality, and whereas the association with target-organ damage in children is not as definitive, early evidence does seem to parallel the adult data. In addition to confirming hypertension at diagnosis, ABP monitoring may be useful for identifying isolated nocturnal hypertension, characterizing BP patterns, and assessing response to therapeutic interventions. This article reviews current evidence supporting the use of ABP monitoring in children and discusses limitations in our understanding of this technology, specifically focusing on indications for its use and interpretation of the large quantity of data obtained by ABP monitoring.