Primary versus secondary hypertension in children followed up at an outpatient tertiary unit

Secondary Hypertension in Children-Identifying and Investigating at Risk Children

PURPOSE OF REVIEW

We aim to review the most recent literature on demographic features and diagnostic workup of children with secondary hypertension, in order to provide a framework for health providers to determine which hypertensive pediatric patients warrant further investigation for secondary causes. By highlighting the utility of various diagnostic investigations, we aim to minimize unnecessary testing burden.

RECENT FINDINGS

A recent meta-analysis revealed that hypertensive children and adolescents with any of the following features were at increased risk of secondary hypertension: < 6 years of age, history of prematurity, family history of secondary hypertension, body mass index (BMI) < 10th percentile. Based on available evidence, we suggest a testing schema that is stratified by both age and BMI. Limited evidence suggest renal ultrasound may be one of the most useful initial investigations for secondary causes in asymptomatic hypertensive children. Lipid profile in overweight/obese children, and echocardiogram for end organ involvement may have high yield of abnormal results. Further studies on the diagnostic utility of tests for secondary hypertension are required, as the current body of evidence is limited.

Current etiology of hypertension in European children - factors associated with primary hypertension

BACKGROUND

While hypertension (HT) in pediatric patients is often secondary (SH), recent trends show a rise in primary hypertension (PH), which is associated with an increasing global prevalence of obesity. A relationship between serum uric acid and PH has also been suggested. Our study aimed to assess the etiology of HT and factors associated with PH in a large European cohort of children referred for HT based on office blood pressure (BP) measurements.

METHODS

We performed a retrospective analysis of 2008 children aged 0-18 years (12.3 ± 4.9 years) diagnosed with HT. Patients were classified into white coat hypertension (WCH), PH, or SH groups based on office BP, 24-h ambulatory BP monitoring (ABPM) and clinical evaluation. Anthropometric, hemodynamic, and biochemical data were collected.

RESULTS

Out of 2008 patients included in the analysis, 200 (10%) were excluded due to multifactorial HT diagnosis after kidney transplantation (KTx). Among the remaining patients HT was confirmed in 1260 (548 were classified as WCH). Of 1260 patients with HT: 49.3% had PH, while 50.7% SH, mainly secondary to renal parenchymal disease (43.5% of SH patients), aortic coarctation (20.7%), and renovascular HT (18%). Age > 12.5 years, obesity (BMI SDS (standard deviation score) ≥ 1.65), and serum uric acid > 4.8 mg/dL were identified as significant factors associated with PH.

CONCLUSIONS

Our study provides valuable insights into the current etiology of pediatric HT and highlights the role of age, obesity, and uric acid level in the diagnosis of PH in children.

Clinical guidelines for the diagnosis, evaluation, and management of hypertension for Korean children and adolescents: the Korean Working Group of Pediatric Hypertension

Pediatric hypertension (HTN) is a significant, growing health concern worldwide and also in Korea. Diagnosis, evaluation, and treatment of HTN in Korean children and adolescents are uncertain due to limitations in using the current international guidelines, since the recommendations by the American Academy of Pediatrics (AAP) and European Society of Hypertension (ESH) guidelines differ. Furthermore, these are guidelines for Western youth, who are racially and ethnically different from Koreans. In addition, reference blood pressure values for all pediatric age groups, which are essential for the diagnosis of HTN according to these two guidelines, are absent in Korea. Therefore, HTN guidelines for Korean children and adolescents should be established. The Korean Working Group of Pediatric Hypertension established clinical guidelines for the diagnosis, evaluation, and management of HTN in Korean children and adolescents. These guidelines were based on reported clinical evidence, expert recommendations, and AAP and ESH guidelines. The characteristics of Korean youth and the Korean medical and insurance system were considered during the establishment of the guidelines. By providing recommendations suitable for Korean youth, these guidelines will help in the prevention and management of childhood HTN, thus relieving the burden of cardiovascular disease in adulthood in Korea.

Yield of diagnostic testing in evaluating etiology and end organ effects of pediatric hypertension

BACKGROUND

Current recommendations regarding the utility of diagnostic investigations for pediatric hypertension are based on limited evidence, leading to wide practice variation. The objective of this study was to characterize the cohort of children that may benefit from secondary hypertension workup, and determine the diagnostic yield of investigations.

METHODS

This was a single-center, retrospective cohort study of 169 children aged 1-18 years referred between 2000 and 2015, to a tertiary pediatric nephrology center in Canada, for evaluation of hypertension. The number of investigations completed, abnormal findings, and diagnostic findings that helped establish hypertension etiology was determined.

RESULTS

56 children were diagnosed with primary and 72 children with secondary hypertension in the outpatient setting. Secondary hypertension was predominant at all ages except for obese adolescents ≥ 12 years. Half of children with traditional risk factors for primary hypertension, including obesity, were diagnosed with secondary hypertension. Kidney ultrasound had the highest yield of diagnostic results (19.8%), with no difference in yield between age groups (P = 0.19). Lipid profile had a high yield of abnormal results (25.4%) as part of cardiovascular risk assessment but was only abnormal in overweight/obese children. Echocardiogram had a high yield for identification of target-organ effects in hypertensive children (33.3%).

CONCLUSION

A simplified secondary hypertension workup should be considered for all hypertensive children and adolescents. High yield investigations include a kidney ultrasound, lipid profile for overweight/obese children, and echocardiograms for assessment of target-organ damage. Further testing could be considered based on results of initial investigations for the most cost-effective management. A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinical characteristics of pediatric hypertension: a multicenter study in China

OBJECTIVES

Hypertension in children has attracted increasing attention. However, clinical-based studies investigating characteristics and secular trends of pediatric hypertension remain limited. This study aimed to investigate the clinical characteristics and secular trends of different types of hypertension among hospitalized children in China.

METHODS

This retrospective analysis was based on medical records from nine tertiary children's hospitals in China during 2010∼2020. A total of 5847 pediatric inpatients (aged <18 years) with the diagnosis of hypertension were enrolled. Information on the clinical characteristics of each patient was obtained from their first admission records.

RESULTS

During the past decade, secondary hypertension sustained to be the dominant type of hypertension in children, with the proportion increased from 51.2% during 2010∼2015 to 59.8% during 2016∼2020. The main causes of secondary hypertension were neurologic disorders in children aged 0∼2 years, which changed to renal diseases after 3 years of age. Compared with primary hypertension, secondary hypertension was common in girls (43.1 vs. 23.3%) and children under 5 years of age (32.2 vs. 2.1%). Moreover, over four-fifths of primary hypertensive individuals had obesity and obesity-related comorbidities, and the proportion of clusters of one or more comorbidities increased in the past decade (79.7 → 85.2%).

CONCLUSION

Secondary hypertension sustained to be the dominant type of hypertension among children, especially in girls. Renal diseases were the most common causes of secondary hypertension in children, followed by rheumatic immune diseases. For primary hypertension, over four-fifths of inpatients had obesity and obesity-related diseases, and the proportion kept rising.

Demographics of childhood hypertension in the UK: a report from the Southeast England

We aimed to describe hypertensive phenotype and demographic characteristics in children and adolescents referred to our paediatric hypertension service. We compared age, ethnicity and BMI in primary hypertension (PH) compared to those with secondary hypertension (SH) and white coat hypertension (WCH). Demographic and anthropometric data were collected for children and adolescents up to age 18 referred to our service for evaluation of suspected hypertension over a 6 year period. Office blood pressure (BP) and out of office BP were performed. Patients were categorised as normotensive (normal office and out of office BP), WCH (abnormal office BP, normal out of office BP), PH (both office and out of office BP abnormal, no underlying cause identified) and SH (both office and out of office BP abnormal, with a secondary cause identified). 548 children and adolescents with mean ± SD age of 10.1 ± 5.8 years and 58.2% girls. Fifty seven percent (n = 314) were hypertensive; of these, 47 (15%), 84 (27%) and 183 (58%) had WCH, PH and SH, respectively. SH presented throughout childhood, whereas PH and WCH peaked in adolescence. Non-White ethnicity was more prevalent within those diagnosed with PH than both the background population and those diagnosed with SH. Higher BMI z-scores were observed in those with PH compared to SH. Hypertensive children <6 years are most likely to have SH and have negligible rates of WCH and PH. PH accounted for 27% of hypertension diagnoses in children and adolescents, with the highest prevalence in adolescence, those of non-White Ethnicity and with excess weight.

Monogenic forms of low-renin hypertension: clinical and molecular insights

Monogenic disorders of hypertension are a distinct group of diseases causing dysregulation of the renin-angiotensin-aldosterone system and are characterized by low plasma renin activity. These can chiefly be classified as causing (i) excessive aldosterone synthesis (familial hyperaldosteronism), (ii) dysregulated adrenal steroid metabolism and action (apparent mineralocorticoid excess, congenital adrenal hyperplasia, activating mineralocorticoid receptor mutation, primary glucocorticoid resistance), and (iii) hyperactivity of sodium and chloride transporters in the distal tubule (Liddle syndrome and pseudohypoaldosteronism type 2). The final common pathway is plasma volume expansion and catecholamine/sympathetic excess that causes urinary potassium wasting; hypokalemia and early-onset refractory hypertension are characteristic. However, several single gene defects may show phenotypic heterogeneity, presenting with mild hypertension with normal electrolytes. Evaluation is based on careful attention to family history, physical examination, and measurement of blood levels of potassium, renin, and aldosterone. Genetic sequencing is essential for precise diagnosis and individualized therapy. Early recognition and specific management improves prognosis and prevents long-term sequelae of severe hypertension.

Prevalence of Secondary Hypertension in Otherwise Healthy Youths with a New Diagnosis of Hypertension: A Meta-Analysis

OBJECTIVE

To estimate the prevalence of secondary hypertension among otherwise healthy children with hypertension diagnosed in the outpatient setting.

STUDY DESIGN

The MEDLINE, PubMed Central, Embase, Web of Science, and Cochrane Library databases were systematically searched for observational studies reporting the prevalence of secondary hypertension in children who underwent evaluation for hypertension and had no known comorbidities associated with hypertension at the time of diagnosis. Two authors independently extracted the study-specific prevalence of secondary hypertension in children evaluated for hypertension. Prevalence estimates for secondary hypertension were pooled in a random-effects meta-analysis.

RESULTS

Nineteen prospective studies and 7 retrospective studies including 2575 children with hypertension were analyzed, with a median of 65 participants (range, 9-486) in each study. Studies conducted in primary care or school settings reported a lower prevalence of secondary hypertension (3.7%; 95% CI, 1.2%-7.2%) compared with studies conducted in referral clinics (20.1%; 95% CI, 11.5%-30.3%). When stratified by study setting, there were no significant subgroup differences according to study design, country, participant age range, hypertension definition, blood pressure device, or study quality. Although the studies applied different approaches to diagnosing secondary hypertension, diagnostic evaluations were at least as involved as the limited testing recommended by current guidelines.

CONCLUSIONS

The low prevalence of secondary hypertension among children with a new diagnosis of hypertension identified on screening reinforces clinical practice guidelines to avoid extensive testing in the primary care setting for secondary causes in most children with hypertension.

Postnatal urinary tract dilatation classification: improvement of the accuracy in predicting kidney injury

BACKGROUND

The grading of urinary tract dilatation (UTD) on postnatal sonography is a fundamental step to establish rational management for infants with antenatal hydronephrosis (ANH). The aim of this study was to compare the prediction accuracy of UTD grading systems for relevant clinical outcomes. In addition, we propose a refinement of the UTD classification by adding quantitative measurements and evaluate its impact on accuracy.

METHODS

Between 1989 and 2019, 447 infants diagnosed with isolated AHN were prospectively followed. The events of interest were surgical interventions and kidney injury. Comparison of performance of the grading systems and the impact on the accuracy of a modified UTD classification (including the size of the kidney parenchyma) was assessed by the area under the receiver-operating characteristic curve (AUC).

RESULTS

Of 447 infants, 131 (29%) underwent surgical intervention and 26 (5.8%) had developed kidney injury. The median follow-up time was 9 years (IQ range, 7-12 years). The performance for detecting the need for surgical intervention was excellent for all grading systems (AUC > 0.90). However, for predicting kidney injury, the modified UTD classification exhibited significant improvement in accuracy (AUC = 0.913, 95%CI, 0.883-0.937) as compared with UTD classification (AUC = 0.887, 95%CI, 0.854-0.915) (P = 0.027).

CONCLUSIONS

Our study confirms that the hydronephrosis grading systems provide excellent accuracy in discriminating patients who need surgical intervention among infants with AHN. Our findings suggest that the inclusion of kidney parenchymal thickness to UTD classification might increase the accuracy for predicting infants who may develop kidney injury. A higher resolution version of the Graphical abstract is available as Supplementary information.

Guidelines for screening and managing hypertension in children

ABSTRACT

Pediatric hypertension has risen to an overall prevalence of 16.3%. If left untreated, hypertension in children and adolescents can have significant implications for cardiovascular and renal health into adulthood, including stroke, coronary artery disease, kidney disease, and heart failure. In 2017, the American Academy of Pediatrics (AAP) released updated guidelines for the screening, evaluation, and management of pediatric hypertension. This article reviews the definition of pediatric hypertension, describes why the guidelines were updated, and defines treatment protocol. By familiarizing themselves with and applying these guidelines, clinicians will be able to appropriately screen and manage hypertension in children to prevent morbidity into adulthood.

Hypertension in Children and Adolescents: A Position Statement From a Panel of Multidisciplinary Experts Coordinated by the French Society of Hypertension

Hypertension is much less common in children than in adults. The group of experts decided to perform a review of the literature to draw up a position statement that could be used in everyday practice. The group rated recommendations using the GRADE approach. All children over the age of 3 years should have their blood pressure measured annually. Due to the lack of data on cardiovascular morbidity and mortality associated with blood pressure values, the definition of hypertension in children is a statistical value based on the normal distribution of blood pressure in the paediatric population, and children and adolescents are considered as having hypertension when their blood pressure is greater than or equal to the 95th percentile. Nevertheless, it is recommended to use normative blood pressure tables developed according to age, height and gender, to define hypertension. Measuring blood pressure in children can be technically challenging and several measurement methods are listed here. Regardless of the age of the child, it is recommended to carefully check for a secondary cause of hypertension as in 2/3 of cases it has a renal or cardiac origin. The care pathway and principles of the therapeutic strategy are described here.

Secondary Hypertension in Children and Adolescents: Novel Insights

Hypertension is a significant risk factor for cardiovascular morbidity and mortality, not only in adults, but in youths also, as it is associated with long-term negative health effects. The predominant type of hypertension in children is the secondary hypertension, with the chronic kidney disease being the most common cause, however, nowadays, there is a rising incidence of primary hypertension due to the rising incidence of obesity in children. Although office blood pressure has guided patient management for many years, ambulatory blood pressure monitoring provides useful information, facilitates the diagnosis and management of hypertension in children and adolescents, by monitoring treatment and evaluation for secondary causes or specific phenotypes of hypertension. In the field of secondary hypertension, there are numerous studies, which have reported a strong association between different determinants of 24-hour blood pressure profile and the underlying cause. In addition, in children with secondary hypertension, ambulatory blood pressure monitoring parameters offer the unique advantage to identify pediatric low- and high-risk children for target organ damage. Novel insights in the pathogenesis of hypertension, including the role of perinatal factors or new cardiovascular biomarkers, such as fibroblast growth factor 23, need to be further evaluated in the near future.

Diagnosis and Management of Endocrine Hypertension in Children and Adolescents

Hypertension in childhood and adolescence has increased in prevalence. Interest in the disease was raised after the 2017 clinical practice guidelines of the American Academy of Paediatrics on the definition and classification of paediatric hypertension. Among the secondary causes of paediatric hypertension, endocrine causes are relatively rare but important due to their unique treatment options. Excess of catecholamine, glucocorticoids and mineralocorticoids, congenital adrenal hyperplasia, hyperaldosteronism, hyperthyroidism and other rare syndromes with specific genetic defects are endocrine disorders leading to paediatric and adolescent hypertension. Adipose tissue is currently considered the major endocrine gland. Obesity-related hypertension constitutes a distinct clinical entity leading to an endocrine disorder. The dramatic increase in the rates of obesity during childhood has resulted in a rise in obesity-related hypertension among children, leading to increased cardiovascular risk and associated increased morbidity and mortality. This review presents an overview of pathophysiology and diagnosis of hypertension resulting from hormonal excess, as well as obesity-related hypertension during childhood and adolescence, with a special focus on management.

Clinical assessment of primary and secondary hypertension in children and adolescents

The aim of this study was to compare the clinical features of patients with elevated blood pressure and to detect variables associated with the diagnosis of primary hypertension. We identified 383 (69%) hypertensive children (197 [51.5%] with primary hypertension, and 186 [48.5%] with secondary hypertension) out of 553 children referred to our clinic with a history of elevated blood pressure. The primary hypertension group was significantly older and had higher BMI, positive family history of hypertension, and lower prevalence of preterm birth compared with those with secondary hypertension. No difference was found between the two groups in terms of the frequency of target organ damage. Multiple regression analysis showed that a family history of hypertension, obesity, age over 10 years, elevated uric acid, and presence of higher systolic blood pressure values at admission were independent predictors of primary hypertension; therefore, these parameters can be considered important clues for diagnosing primary hypertension.

National data with high validity and completeness showed that only 0.04% of Danish children had been registered with diagnosed hypertension

AIM

Hypertension has been reported in up to 4.0% of American children, but no national data exist in Europe. We studied the frequency of registered hypertension in Danish children and evaluated the data.

METHODS

This 2014-2015 study focused on patients under the age of 16 registered with hypertension in the Danish National Patient Register and 10 paediatric departments in central and eastern Denmark. The diagnoses were coded according to the International Classification of Diseases, 10th revision. All the subjects' medical records were reviewed, including any confirmed diagnoses.

RESULTS

There were 55 784 children under 16 in the study regions at 30 April 2014. By May 2015, 222 of those had been registered with hypertension: 200 in the Danish National Patient Register and 191 in the 10 paediatric departments. Their medical records confirmed hypertension in 187 and 185 cases, respectively. The prevalence of registered and confirmed hypertension was 222/553 784 (0.04%). The positive predictive values of hypertension were 187/200 (94%) and 185/191 (97%), and the completeness of diagnosed hypertension was 187/222 (84%) and 185/222 (83%).

CONCLUSION

The registers had high-quality positive predictive values and completeness, but only 0.04% of the Danish children were registered with a verified diagnosis of hypertension.

Diagnostically Challenging Case of Renal Artery Stenosis in a Pediatric Patient

In this study we report a diagnostically challenging case of bilateral renal artery stenosis (RAS) in a nine-year-old boy presenting as uncontrolled hypertension (HTN). The objective of this clinical case report is to draw attention to the unlikely combination of a classical clinical presentation with several normal investigations.

This is a nine-year-old boy, known to have uncontrolled HTN, later diagnosed as a case of bilateral RAS. This patient underwent several imaging studies including: renal Doppler ultrasonography (US), diethylenetriamine pentaacetic acid (DTPA) scan, and mercaptuacetyltriglycine (MAG3) renal scintigraphy with captopril challenge, with the aim of determining the cause of his uncontrolled HTN. The previously mentioned imaging procedures were carried out at two different medical centers over an extended period of time; however, the images failed to show any anatomical abnormalities to explain his clinical presentation. Due to this unexpected result the primary team in charge of this case opted for a percutaneous transluminal angioplasty, as a diagnostic and therapeutic approach, by which the final diagnosis of bilateral RAS was concluded. During follow-up the patient was asymptomatic in all outpatient clinic appointments.

Even though several initial investigations failed to indicate RAS, clinicians may pursue further investigations in cases of classical clinical presentation of uncontrolled HTN in pediatric population so as to not miss any diagnostically challenging cases.

Pediatric Hypertension

The prevalence of elevated blood pressure and hypertension in children and adolescents has increased over the past decade. This trend is most likely related to increases in primary hypertension associated with increasing obesity rates in children. Lifestyle as well as genetics play a significant role in the development of primary hypertension. Hypertension in children and adolescents is under-recognized and undertreated. The 2017 Revised Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents aimed to create new normative blood pressure tables using data from healthy weight children, meaning between the 5th and 85th percentile per the Centers for Disease Control and Prevention. Another important objective was to simplify normative data to ease screening and detection of elevated blood pressures. The consequences of chronic hypertension are significant, with its major affect being in poor cardiovascular health outcomes both in childhood and early adulthood. Challenges to detection and adequate treatment should be overcome with continued education and awareness to prevent the long-term effects of uncontrolled hypertension that starts in childhood. [Pediatr Ann. 2018;47(12):e499-e503.].

2016 European Society of Hypertension guidelines for the management of high blood pressure in children and adolescents

Increasing prevalence of hypertension (HTN) in children and adolescents has become a significant public health issue driving a considerable amount of research. Aspects discussed in this document include advances in the definition of HTN in 16 year or older, clinical significance of isolated systolic HTN in youth, the importance of out of office and central blood pressure measurement, new risk factors for HTN, methods to assess vascular phenotypes, clustering of cardiovascular risk factors and treatment strategies among others. The recommendations of the present document synthesize a considerable amount of scientific data and clinical experience and represent the best clinical wisdom upon which physicians, nurses and families should base their decisions. In addition, as they call attention to the burden of HTN in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, these guidelines should encourage public policy makers to develop a global effort to improve identification and treatment of high blood pressure among children and adolescents.

Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents

These pediatric hypertension guidelines are an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." Significant changes in these guidelines include (1) the replacement of the term "prehypertension" with the term "elevated blood pressure," (2) new normative pediatric blood pressure (BP) tables based on normal-weight children, (3) a simplified screening table for identifying BPs needing further evaluation, (4) a simplified BP classification in adolescents ≥13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, (5) a more limited recommendation to perform screening BP measurements only at preventive care visits, (6) streamlined recommendations on the initial evaluation and management of abnormal BPs, (7) an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and (8) revised recommendations on when to perform echocardiography in the evaluation of newly diagnosed hypertensive pediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy. These guidelines include 30 Key Action Statements and 27 additional recommendations derived from a comprehensive review of almost 15 000 published articles between January 2004 and July 2016. Each Key Action Statement includes level of evidence, benefit-harm relationship, and strength of recommendation. This clinical practice guideline, endorsed by the American Heart Association, is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient diagnoses and outcomes, support implementation, and provide direction for future research.

Ultrasound imaging of renin-mediated hypertension

The incidence of primary (i.e. essential) hypertension in children and adolescents is increasing; however, secondary hypertension, with an identifiable cause, remains relatively common and might be treatable or even curable. Renovascular hypertension is an uncommon but important secondary cause of hypertension in the pediatric population that can be associated with substantial morbidity. In this article we discuss renin-mediated causes of hypertension in children and related complications, review renal Doppler ultrasound techniques for the evaluation of renin-mediated hypertension (including both direct and indirect assessments), and briefly appraise the literature pertaining to renal Doppler ultrasound and the assessment of pediatric hypertension. Finally, we describe a proposed role for renal Doppler ultrasound in the workup of suspected renin-mediated hypertension in children and adolescents.

Remedial operations for failed endovascular therapy of 32 renal artery stenoses in 24 children

BACKGROUND

Percutaneous transluminal angioplasty (PTA) for the treatment of pediatric renovascular hypertension (RVH) in contemporary practice is accompanied with ill-defined complications. This study examines the mode of pediatric renal PTA failures and the results of their surgical management.

METHODS

Twenty-four children underwent remedial operations at the University of Michigan from 1996 to 2014 for failures of renal PTA. Their clinical courses were retrospectively reviewed and results analyzed.

RESULTS

Renal PTA of 32 arteries, including 13 with stenting, was performed for severe RVH in 12 boys and 12 girls, having a mean age of 9.3 years. Developmental ostial stenoses affected 22 children. PTA failures included: 27 restenoses and five thromboses. Remedial operations included: 13 renal artery-aortic reimplantations, one segmental renal artery-main renal artery reimplantation, ten aortorenal bypasses, one arterioplasty, one iliorenal bypass, and six nephrectomies for unreconstructable arteries; the latter all in children younger than 10 years. Follow-up averaged 2.1 years. Postoperatively, hypertension was cured, improved, or unchanged in 25, 54, and 21 %, respectively. There was no perioperative renal failure or mortality.

CONCLUSIONS

Renal PTA for the treatment of pediatric RVH due to ostial disease may be complicated by failures requiring complex remedial operations or nephrectomy, the latter usually affecting younger children.

Essential hypertension vs. secondary hypertension among children

BACKGROUND

The aim was to determine the proportions and correlates of essential hypertension among children in a tertiary pediatric hypertension clinic.

METHODS

We evaluated 423 consecutive children and collected demographic and clinical history by retrospective chart review.

RESULTS

We identified 275 (65%) hypertensive children (blood pressure >95th percentile per the "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents") from 423 children referred to the clinic for history of elevated blood pressure. The remainder of the patients had normotension (11%), white coat hypertension (11%), prehypertension (10%), and pending diagnosis (3%). Among the 275 hypertensive children, 43% (n = 119; boys = 56%; median age = 12 years; range = 3-17 years) had essential hypertension and 57% (n = 156; boys = 66%; median age = 9 years; range = 0.08-19 years) had secondary hypertension. When compared with those with secondary hypertension, those with essential hypertension had a significantly older age at diagnosis (P = 0.0002), stronger family history of hypertension (94% vs. 68%; P < 0.0001), and lower prevalence of preterm birth (20% vs. 46%; P < 0.001). There was a bimodal distribution of age of diagnosis in those with secondary hypertension.

CONCLUSIONS

The phenotype of essential hypertension can present as early as 3 years of age and is the predominant form of hypertension in children after age of 6 years. Among children with hypertension, those with essential hypertension present at an older age, have a stronger family history of hypertension, and have lower prevalence of preterm birth.

Duplex ultrasound findings before and after surgery in children and adolescents with renovascular hypertension

We report our experience with duplex ultrasound in young patients with renal artery stenosis (RAS) or middle aortic syndrome (MAS) before and after surgery (1995 and 2009). Of 36 patients (mean age: 13 ± 7 y), 21 had RAS and 15 had MAS. For patients with RAS, the Vmax in the affected artery was 350 ± 111 cm/s before surgery and 145 ± 55 cm/s after surgery. The resistance index was 0.46 ± 0.1 in the post-stenotic kidney and increased to 0.60 ± 0.08 after revascularization. Determination of the flow profile in the iliac artery revealed triphasic flow. In individuals with MAS, Vmax in the aorta was 323 ± 98 and the resistance index in both kidneys was low, even in the absence of RAS. The flow profile in the iliac arteries was monophasic before surgery and became triphasic after surgery. Duplex ultrasound is useful for the evaluation of children and young adults both pre- and post-surgery. Duplex ultrasound criteria for RAS in adults appear to be applicable in children and young adults also. The diagnostic evaluation of suspected renal vascular disease should include assessment of the aorta and the flow profile in the iliac arteries, as this could help differentiate between aortic and isolated renal artery stenosis.

Essential pediatric hypertension: defining the educational needs of primary care pediatricians

BACKGROUND

In order to better understand the educational needs regarding appropriate recognition, diagnosis and management of pediatric hypertension (HTN), we asked practicing pediatricians questions regarding their educational needs and comfort level on this topic.

METHODS

We conducted 4 focus group sessions that included 27 participants representing pediatric residents, adolescent medicine physicians, clinic based pediatricians and office based pediatricians. Each focus group session lasted for approximately an hour and 90 pages of total transcriptions were produced verbatim from audio recordings.

RESULTS

Four reviewers read each transcript and themes were elucidated from these transcripts. Overall, 5 major themes related to educational needs and clinical concerns were found: utilization of resources to define blood pressure (BP), correct BP measurement method(s), co-morbidities, barriers to care, and experience level with HTN. Six minor themes were also identified: differences in BP measurement, accuracy of BP, recognition of HTN, practice pattern of care, education of families and patients, and differences in level of training. The focus group participants were also questioned on their preferences regarding educational methods (i.e. e-learning, small group sessions, self-study, large group presentations) and revealed varied teaching and learning preferences.

CONCLUSIONS

There are multiple methods to approach education regarding pediatric HTN for primary care pediatricians based on provider preferences and multiple educational activities should be pursued to achieve best outcomes. Based on this data, the next direction will be to develop and deliver multiple educational methods and to evaluate the impact on practice patterns of care for children and adolescents with HTN.

Renal sonography with Doppler for detecting suspected pediatric renin-mediated hypertension - is it adequate?

BACKGROUND

Renal Doppler US is used to evaluate suspected vascular causes of hypertension in children, despite mostly unknown diagnostic performance characteristics.

OBJECTIVE

To evaluate renal Doppler US for detecting vascular causes of hypertension in children with high clinical suspicion of aortic or renal artery narrowing.

MATERIALS AND METHODS

We identified pediatric renal Doppler US examinations performed for hypertension between January 1995 and June 2010 at our institution. We excluded children without follow-up angiography (CT-, MR-, or catheter-based). Two pediatric radiologists reviewed imaging studies and documented relevant findings. Intrarenal spectral Doppler resistive index measurement <0.5 or tardus parvus waveform constituted a positive examination.

RESULTS

Thirty-five boys and 13 girls underwent renal Doppler US and confirmatory imaging (mean age  =  9.0 years). Nineteen US examinations were truly negative, two were falsely negative, 18 were truly positive (16 involved narrowing of the aorta or main renal artery) and nine were falsely positive. Sonography had a sensitivity and specificity of 90% and 68%, respectively, for detecting a vascular cause of hypertension.

CONCLUSION

Renal Doppler sonography reliably detects renin-mediated hypertension caused by aortic or main renal artery narrowing in children. More studies are needed to determine its ability to detect intrarenal and accessory renal artery stenoses.

Hypertension associated with coarctation of the aorta revisited: case-based update from experience of three children

Coarctation of the aorta (CoA) can present with different clinical pictures depending on the severity of the narrowness in the coarcted aortic segment in an age range between newborn and adolescence. Sometimes, it can cause intracranial hemorrhage or infarction when diagnosis and treatment are delayed. The aim of this report is taking attention to CoA as a cause of systemic hypertension and is also emphasizing the differences of diagnostic approach for hypertension in children from adults. Two cases of hypertensive cerebral hemorrhage and one case of hypertensive cerebellar infarction associated with CoA are reported. These cases help us to pay attention to the possibility of CoA in adolescents with hypertensive stroke. We want to emphasize the importance of physical examination for evaluation of hypertension and to impress the diagnostic approach for secondary hypertension in children.

Clinical and demographic characteristics of children with hypertension

Most information describing hypertension in the young comes from single-center reports. To better understand contemporary demographic and clinical characteristics of hypertensive children and adolescents, we examined baseline data on 351 children aged 1 to <17 years old who were enrolled in 2 multicenter trials of valsartan. Anthropometric, laboratory, and demographic information at randomization was extracted from the clinical trials databases. Summary variables were created and compared for 3 age groups: <6 years (n=90), 6 to <12 years (n=131), and 12 to <17 years (n=130). Comparisons were also made between different etiologies of hypertension and for different anthropometric categories. Children<6 years old were significantly more likely to have secondary hypertension and were significantly less likely to have weight or body mass index>95 percentile compared with older children. Estimated glomerular filtration rate was significantly lower in children<6 years old (90.9±31.8 mL/min per 1.73 m2) than in the other 2 age groups (6 to <12 years, 141.4±42.1 mL/min per 1.73 m2; 12 to <17 years, 138.3±46.0 mL/min per 1.73 m2). Frequency of total cholesterol>95 percentile was significantly lower in children aged<6 years. Diastolic blood pressure index (subject blood pressure÷95 percentile) was significantly higher in children<6 years old (1.1 versus 1.0 in both the 6 to <12 years and 12 to <17 years groups; both P<0.0001). We conclude that hypertensive children<6 years are more likely to have secondary hypertension and to have higher diastolic blood pressure and lower glomerular filtration rate and are less likely to be obese or to have elevated cholesterol than school-aged children or adolescents. These findings emphasize unique aspects of childhood hypertension that should be considered when evaluating children and adolescents with elevated blood pressure and in designing future clinical trials.

Clinical course of 822 children with prenatally detected nephrouropathies

BACKGROUND AND OBJECTIVES

With the advent of fetal screening ultrasonography, the detection of congenital anomalies of the kidney and urinary tract (CAKUT) in utero has permitted early management of these conditions. This study aims to describe the clinical course of a large cohort of patients with prenatally detected nephrouropathies.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this retrospective cohort study, 822 patients were prenatally diagnosed with CAKUT and systematically followed up at a tertiary Renal Unit for a median time of 43 months. Variables included in the analysis were sex, laterality, fetal ultrasonography (isolated versus associated hydronephrosis), and presence/absence of nephrouropathies. The events of interest were urinary tract infection, surgical interventions, hypertension, CKD, and death. Survival analyses were performed to evaluate time until occurrence of the events of interest.

RESULTS

Urinary tract infection occurred in 245 (29.8%) children, with higher risk in females (hazard ratio=1.30, 95% confidence interval=1.02-1.70, P=0.05); 22 patients (2.7%) had hypertension, and 49 (6%) patients developed CKD. The risk of CKD was greater in patients with associated hydronephrosis (hazard ratio=5.20, 95% confidence interval=2.90-9.30, P<0.001). Twelve patients (1.5%) died during follow-up. Death was significantly associated with being born during the first period of the study (hazard ratio=6.00, 95% confidence interval=1.60-22.50, P<0.001), associated hydronephrosis (hazard ratio=9.30, 95% confidence interval=2.90-29.30, P<0.001), and CKD (hazard ratio=170.00, 95% confidence interval=41.00-228.00, P<0.001).

CONCLUSIONS

In our series, the clinical course of prenatally detected CAKUT was heterogeneous, and those infants with associated hydronephrosis at baseline were identified as a high-risk subgroup.