Control of hypertension in children after renal transplantation

Etiology, risk factors and management of hypertension post liver transplantation

BACKGROUND

Cardiovascular events are one of the most important causes of morbidity and mortality in the long-term follow-up of liver transplant recipients. Hypertension is a significant cardiovascular risk factor that occurs frequently after pediatric liver transplantation. Chronic use of immunosuppressants - mainly calcineurin inhibitors - plays a major role in the development of post-transplant hypertension and circadian disturbances such as flattening of the nocturnal blood pressure dip. This requires special attention in children given the long timeframe during which immunosuppressive therapy is necessary. Careful and structured blood pressure monitoring and adequate treatment of hypertension are essential to optimize the quality of life and life expectancy of pediatric liver transplant patients. However, evidence-based guidelines for monitoring and management of post-transplant hypertension and its complications are lacking.

METHODS

We conducted a comprehensive review of the current knowledge and practices concerning post-transplant hypertension. The databases Pubmed, Embase, Web of Science and Google Scholar were scanned with the following keywords: pediatric liver transplantation, immunosuppression, tacrolimus, cardiovascular effects, hypertension, heart function, kidney function, circadian rhythm, mechanism, monitoring, and management.

RESULTS

In this review, we describe the incidence and etiology of hypertension in pediatric liver transplant recipients, the underlying mechanisms and characteristics of calcineurin inhibitor-induced hypertension, and the consequences of and risk factors for post-transplant hypertension. We hereby present an overview of the current practices in blood pressure monitoring and antihypertensive treatment as well as an algorithm for the evaluation and management of hypertension post liver transplantation. Finally, we discuss knowledge gaps and suggestions for future research.

Arterial stiffness and blood pressure increase in pediatric kidney transplant recipients

BACKGROUND

Pulse wave velocity (PWV) is a measure of arterial stiffness. We investigated PWV and blood pressure (BP) to determine to what extent BP changes contribute to arterial stiffness, and secondly, to identify influencing factors on BP in children after kidney transplantation.

METHODS

Seventy children ≥ 2.5 years post-transplantation with at least two PWV measurements were included. Changes of systolic (Δ SBP) and diastolic BP (Δ DBP) were classified into "stable/decreasing," "1-10 mmHg increase," and " > 10 mmHg increase." Linear mixed modeling for PWV z-score (PWVz) adjusted either for Δ SBP or Δ DBP was performed. An extended dataset with monthly entries of BP, immunosuppression, and creatinine was obtained in 35 participants over a median of 74 months to perform linear mixed modeling for SBP and DBP.

RESULTS

PWVz increased with a rate of 0.11/year (95% CI 0.054 to 0.16). Compared to participants with stable BP, those with 1-10-mmHg SBP and DBP increase showed a higher PWVz of 0.59 (95% CI 0.046 to 1.13) and 0.86 (95% CI 0.43 to 1.30), respectively. A > 10-mmHg BP increase was associated with an even higher PWVz (SBP β = 0.78, 95% CI 0.22 to 1.34; DBP β = 1.37, 95% CI 0.80 to 1.94). Female sex and participants with lower eGFR showed higher PWVz. In the extended analysis, DBP was positively associated with cyclosporin A and everolimus trough levels.

CONCLUSIONS

A higher increase of PWV is seen in patients with greater BP increase, with higher cyclosporin A and everolimus trough levels associated with higher BP. This emphasizes the role of BP as a modifiable risk factor for the improvement of cardiovascular outcome after transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Isolated nocturnal hypertension in pediatric kidney transplant recipients

BACKGROUND

Isolated nocturnal hypertension (INH) is defined as nighttime hypertension in the setting of normal daytime blood pressure (BP), diagnosed by ambulatory BP monitoring (ABPM).

METHODS AND RESULTS

Hypertension affects 60%-80% of pediatric kidney transplant recipients, and INH is the most common type of ambulatory hypertension. INH is associated with an increased prevalence of hypertension-mediated target organ damage such as left ventricular hypertrophy in adults and in pediatric kidney transplant recipients.

CONCLUSION

Ambulatory BP monitoring should be performed annually in all pediatric kidney transplant recipients to diagnose hypertension phenotypes that are not detectable by office BP such as masked hypertension, white-coat hypertension, or INH. Isolated nocturnal hypertension in pediatric transplant patients requires study as a treatment target.

Isolated nocturnal hypertension is associated with increased left ventricular mass index in children

BACKGROUND

Isolated nocturnal hypertension (INH) is associated with increased prevalence of left ventricular hypertrophy (LVH) and cardiovascular morbidity and mortality in adult patients. Unlike in adults, data illustrating the possible association between INH and cardiac target organ damage is lacking in children. This study aimed to investigate whether INH is associated with increased left ventricular mass index (LVMI) and LVH in children.

METHODS

Retrospective data from all untreated children with confirmed ambulatory hypertension (HT) in our center was reviewed. Ambulatory blood pressure monitoring (ABPM) and echocardiography were performed concurrently. Ambulatory normotensive children served as controls. LVH was defined as LVMI ≥ 95th percentile.

RESULTS

There were 102 ABPM studies; of these, 79 children had renal HT, and 23 had primary HT. Median age of children was 13.2 years (3.8-18.9). Nineteen children had INH, 9 children had isolated daytime HT, 54 had daytime and nighttime HT, and 20 were normotensive. The LVMI adjusted for age (patient's LVMI/95th percentile of the LVMI) was significantly higher in children with INH than in normotensive children (0.83 ± 0.03 vs. 0.74 ± 0.03, p = 0.03). Left ventricular hypertrophy was present in 11% of children with INH; this was not significantly higher than in normotensive children (0%, p = 0.23).

CONCLUSIONS

This study investigated the association between INH and cardiac structure in children with primary and renal HT and showed children with INH had higher LVMI adjusted for age than normotensive children and children with INH had similar LVMI adjusted for age to children with isolated daytime HT.

Should ACE inhibitors or calcium channel blockers be used for post-transplant hypertension?

Arterial hypertension in renal transplant recipients warrants antihypertensive treatment. The preferable choice of antihypertensives that should be used in patients after kidney transplantation remains a matter of debate; however, calcium channel blockers (CCB) and angiotensin-converting enzyme inhibitors (ACEI) are currently the most commonly used antihypertensives. This educational review summarizes the current evidence about the effects of these two classes of medications in transplant recipients. Several studies have demonstrated that both classes of drugs can reduce blood pressure (BP) to similar extents. Meta-analyses of adult randomized controlled trials have shown that graft survival is improved in patients treated with ACEIs and CCBs, and that CCBs increase, yet ACEIs decrease, graft function. Proteinuria is usually decreased by ACEIs but remains unchanged with CCBs. In children, no randomized controlled study has ever been performed to compare BP or graft survival between CCBs and ACEIs. Post-transplant proteinuria could be reduced in children along with BP by ACEIs. The results of the most current meta-analyses recommend that due to their positive effects on graft function and survival, along with their lack of negative effects on serum potassium, CCBs could be the preferred first-line antihypertensive agent in renal transplant recipients. However, antihypertensive therapy should be individually tailored based on other factors, such as time after transplantation, presence of proteinuria/albuminuria, or hyperkalemia. Furthermore, due to the difficulty in controlling hypertension, combination therapy containing both CCBs and ACEIs could be a reasonable first-step therapy in treating children with severe post-transplantation hypertension.

Sex and age as determinants for high blood pressure in pediatric renal transplant recipients: a longitudinal analysis of the CERTAIN Registry

BACKGROUND

High prevalence of arterial hypertension is known in pediatric renal transplant patients, but how blood pressure (BP) distribution and control differ between age groups and whether sex and age interact and potentially impact BP after transplantation have not been investigated.

METHODS

This retrospective analysis included 336 pediatric renal transplant recipients (62% males) from the Cooperative European Pediatric Renal Transplant Initiative Registry (CERTAIN) with complete BP measurement at discharge and 1, 2 and 3 years post-transplant.

RESULTS

At discharge and 3 years post-transplant, arterial hypertension was highly prevalent (84% and 77%); antihypertensive drugs were used in 73% and 68% of the patients. 27% suffered from uncontrolled and 9% from untreated hypertension at 3 years post-transplant. Children transplanted at age < 5 years showed sustained high systolic BP z-score and received consistently less antihypertensive treatment over time. Younger age, shorter time since transplantation, male sex, higher body mass index (BMI), high cyclosporine A (CSA) trough levels, and a primary renal disease other than congenital anomalies of the kidney and urinary tract (CAKUT) were significantly associated with higher systolic BP z-score. Sex-stratified analysis revealed a significant association between high CSA and higher systolic BP in older girls that likely had started puberty already. An association between BP and estimated glomerular filtration rate was not detected.

CONCLUSIONS

BP control during the first 3 years was poor in this large European cohort. The description of age- and sex-specific risk profiles identified certain recipient groups that may benefit from more frequent BP monitoring (i.e. young children) or different choices of immunosuppression (i.e. older girls).

Inadequate blood pressure control demonstrated by ambulatory blood pressure monitoring in pediatric renal transplant recipients

BACKGROUND

Adequate BP control in RT recipients should not rely only by normal office BP but also on normal 24-hour BP. This study aims to assess adequacy of BP control by ABPM and to assess ABPM parameters associated with LVMI in pediatric RT recipients.

MATERIALS AND METHODS

Patients aged 5-20 years who have been followed after RT were enrolled. Demographic data and BP assessed by office and ABPM were collected. Echocardiography was performed to detect LVMI.

RESULTS

Thirty RT recipients (18 males) with median age of 15 years (IQR 13-18.5) were included. Among 23 patients who were taking antihypertensive drugs, uncontrolled hypertension was detected in 34.8% and 78.3% by office BP measurement and ABPM, respectively. Thus, the difference in prevalence of uncontrolled hypertension observed by ABPM versus office BP was 43.5%. Those seven patients who were not taking antihypertensive drugs because of normal office BP, four patients (57.1%) had masked hypertension and one patient had elevated BP. Fifteen patients have progression of LVH after RT. Multivariate analysis revealed that age (OR 1.369, 95%CI 0.985-1.904, P-value = 0.062) had a trend to be associated with progression of LVH. Moreover, nighttime systolic BP z-score was significantly correlated with LVMI (r = 0.551, P-value = 0.002).

CONCLUSION

The difference in prevalence of uncontrolled hypertension uncovered by ABPM was 43.5%. Nighttime SBP z-score was significantly correlated with LVMI.

Steroid withdrawal improves blood pressure control and nocturnal dipping in pediatric renal transplant recipients: analysis of a prospective, randomized, controlled trial

BACKGROUND

Variable effects of steroid minimization strategies on blood pressure in pediatric renal transplant recipients have been reported, but data on the effect of steroid withdrawal on ambulatory blood pressure and circadian blood pressure rhythm have not been published so far.

METHODS

In a prospective, randomized, multicenter study on steroid withdrawal in pediatric renal transplant recipients (n = 42) on cyclosporine, mycophenolate mofetil, and methylprednisolone, we performed a substudy in 28 patients, aged 11.2 ± 3.8 years, for whom ambulatory blood pressure monitoring (ABPM) data were available.

RESULTS

In the steroid-withdrawal group, the percentage of patients with arterial hypertension, defined as systolic and/or diastolic blood pressure values recorded by ABPM > 1.64 SDS and/or antihypertensive medication, at month 15 was significantly lower (35.7%, p = 0.002) than in controls (92.9%). The need of antihypertensive medication dropped significantly by 61.2% (p < 0.000 vs. control), while in controls, it even rose by 69.3%. One year after steroid withdrawal, no patient exhibited hypertensive blood pressure values above the 95th percentile, compared to 35.7% at baseline (p = 0.014) and to 14.3% of control (p = 0.142). The beneficial impact of steroid withdrawal was especially pronounced for nocturnal blood pressure, leading to a recovered circadian rhythm in 71.4% of patients vs. 14.3% at baseline (p = 0.002), while the percentage of controls with an abnormal circadian rhythm (35.7%) did not change.

CONCLUSIONS

Steroid withdrawal in pediatric renal transplant recipients with well-preserved allograft function is associated with less arterial hypertension recorded by ABPM and recovery of circadian blood pressure rhythm by restoration of nocturnal blood pressure dipping.

Clinical value of ambulatory blood pressure in pediatric patients after renal transplantation

Hypertension is a highly prevalent co-morbidity in pediatric kidney transplant recipients. Undertreated hypertension is associated with cardiovascular complications and negatively impacts renal graft survival. Thus, the accurate measurement of blood pressure is of the utmost importance for the correct diagnosis and subsequent management of post-renal transplant hypertension. Data derived from the general population, and to a lesser extent from the pediatric population, indicates that ambulatory blood pressure monitoring (ABPM) is superior to blood pressure measurements taken in the clinical setting for the evaluation of true mean blood pressure, identification of patients requiring antihypertensive treatment, and in the prediction of cardiovascular outcome. This Educational Review will discuss the clinical value of ABPM in the identification of individual blood pressure phenotypes, i.e., normotension, new-onset hypertension, white-coat hypertension, masked hypertension, controlled blood pressure, and undertreated/uncontrolled hypertension in pediatric kidney transplant recipients. Finally, we examine the utility of performing repeated ABPM for treatment monitoring of post-renal transplant hypertension and on surrogate markers related to relevant clinical cardiovascular outcomes. Taken together, our review highlights the clinical value of the routine use of ABPM as a tool for identifying and monitoring hypertension in pediatric kidney transplant recipients.

What's new in paediatric hypertension?

Paediatric hypertension predisposes to hypertension and cardiovascular disease in adult life. Despite clear guidelines, there remains a lack of screening. Diagnosis remains challenging given the high rate of false-positive high blood pressure (BP) readings at a single visit; thus, multiple visits are required to confirm the diagnosis. Depending on the normative data sets used, hypertension in overweight and obese children can be underestimated by up to 20%. Specific BP targets are required for subgroups such as adolescents, children with chronic kidney disease (CKD) and type 1 diabetes. High dietary salt intake is a risk factor for cardiovascular disease. Given the rise in processed food consumption, children in developed nations are likely to benefit from salt restriction at a population-based level.

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.

Ambulatory Blood Pressure, Left Ventricular Hypertrophy, and Allograft Function in Children and Young Adults After Kidney Transplantation

BACKGROUND

Hypertension is a common complication and is an important risk factor for graft loss and adverse cardiovascular outcomes in pediatric kidney transplantation. Ambulatory blood pressure monitoring (ABPM) is the preferred method to characterize blood pressure status.

METHODS

We conducted a retrospective review of a large cohort of children and young adults with kidney transplant to estimate the prevalence of abnormal ambulatory blood pressure (ABP), assess factors associated with abnormal ABP, and examine whether ambulatory hypertension is associated with worse allograft function and left ventricular hypertrophy (LVH).

RESULTS

Two hundred twenty-one patients had ABPM, and 142 patients had echocardiographic results available for analysis. One third of the patients had masked hypertension, 32% had LVH, and 38% had estimated glomerular filtration rate less than 60 mL/min per 1.73 m. African-American race/Hispanic ethnicity and requirement for more than 1 antihypertensive medication were independently associated with having masked hypertension. In a multivariate analysis, abnormal blood pressure (masked or sustained hypertension combined) was an independent predictor for LVH among patients not receiving antihypertensive treatment (P = 0.025). In a separate analysis, the use of antihypertensive medications was independently associated with worse allograft function (P = 0.002) although abnormal blood pressure was not a significant predictor.

CONCLUSIONS

In young kidney transplant recipients, elevated ABP is frequently unrecognized and undertreated. The high prevalence of abnormal ABP, including masked hypertension, and its association with LVH supports the case for routine ABPM and cardiac structure evaluation as the standard of care in these patients.

Ambulatory Blood Pressure Monitoring in Frequently Relapsing Nephrotic Syndrome

OBJECTIVES

To screen patients with frequently relapsing nephrotic syndrome (FRNS) for the presence of ambulatory hypertension and left ventricular hypertrophy.

METHODS

Following ethical and parental approvals, consecutive patients with FRNS of ≥2 y duration were enrolled. Those with estimated glomerular filtration rate <60 ml/min/1.73 m² and known familial hypercholesterolemia or diabetes mellitus were excluded. Clinic blood pressure was measured by oscillometry and 24-h ambulatory blood pressure was recorded by Spacelab 90207; echocardiography was done for left ventricular mass. Ambulatory hypertension was defined as the presence of clinic blood pressure >95th centile for age, sex and height, and systolic blood pressure load exceeding 25 %.

RESULTS

Of 99 patients, 73 were boys; their median (IQR) age was 120 (84-156) mo. Clinic blood pressure was >95th percentile in 63 (63.6 %) patients. Ambulatory hypertension was present in 33 (33.3 %), including 14 patients with severe hypertension; 16 (16.1 %) had masked hypertension and 30 (30.3 %) had white coat hypertension. Non-dipping was seen in 72 and 55 patients had high nocturnal systolic blood pressure load. Of 21 patients with increased left ventricular mass index, 9 (42.9 %) had ambulatory hypertension, 3 (14.3 %) had masked hypertension and 6 (28.6 %) patients had white coat hypertension. Compared to those with normal blood pressure, patients with ambulatory hypertension were younger at onset of nephrotic syndrome (odds ratio, OR 0.94; 95 % CI 0.91-0.98; P = 0.002), longer duration of frequently relapsing disease (OR 1.05; 95 % CI 1.00-1.10; P = 0.034) and higher body mass index (BMI) (OR 1.61; 95 % CI 1.07-4.40; P = 0.020). BMI was positively correlated with 24-h systolic blood pressure load (r = 0.23; P = 0.002) and with the left ventricular mass index (r = 0. 57; P = 0.001).

CONCLUSIONS

Many patients with FRNS showed high prevalence of clinic, ambulatory and white coat hypertension, emphasizing the need to carefully screen these patients in order to ensure their appropriate management. While clinic blood pressure monitoring detects most patients with hypertension, it misses a significant proportion with masked hypertension, underscoring the need for ambulatory blood pressure monitoring and screening for end organ damage. High BMI was the chief risk factor for hypertension, suggesting that control of overweight and hypertension might improve cardiovascular outcomes.

Nocturnal blood pressure non-dipping is not associated with increased left ventricular mass index in hypertensive children without end-stage renal failure

The aim of our study was to investigate whether nocturnal blood pressure (BP) dip is associated with increased left ventricular mass index and hypertrophy in children with hypertension (HT). We retrospectively reviewed data from all children with confirmed ambulatory HT in our center and performed ambulatory blood pressure monitoring (ABPM) and echocardiography at the same time. Left ventricular hypertrophy (LVH) was defined as left ventricular mass index (LVMI) ≥95th centile. Non-dipping phenomenon was defined as nocturnal BP dip <10 %. A total of 114 ABPM studies were included, the median age of children was 15.3 years (3.8-18.9), 80 children had renoparenchymal HT without end-stage renal failure, 34 had primary HT, and 27 studies were done on untreated children and 87 on treated children. Non-dipping phenomenon was present in 63 (55 %) studies (non-dippers). The LVMI adjusted for age was not significantly different between non-dippers and dippers (0.87 ± 0.03 vs. 0.81 ± 0.02, p = 0.13). Left ventricular hypertrophy was not significantly higher in non-dippers than in dippers (20 vs. 9 %, p = 0.12).

CONCLUSION

Hypertensive children without end-stage renal failure with non-dipping phenomenon do not have increased prevalence of LVH or higher LVMI adjusted for age than hypertensive children with preserved nocturnal BP dip.

WHAT IS KNOWN

• Adult and pediatric hypertensive patients with end-stage renal failure have often nocturnal blood pressure non-dipping phenomenon. • Non-dipping phenomenon is in patients with end-stage renal failure associated with increased prevalence of left ventricular hypertrophy. What is New: • Pediatric hypertensive patients without end-stage renal failure with blood pressure non-dipping phenomenon do not have increased prevalence of left ventricular hypertrophy.

Long-Term Changes in Blood Pressure After Pediatric Kidney Transplantation

BACKGROUND

Hypertension presents high prevalence rates following kidney transplantation (Tx). The aims of the present study were to investigate the prevalence and possible risk factors for hypertension and blood pressure (BP) control over time after pediatric kidney Tx, as well as to assess possible effects of hypertension on graft survival.

METHODS

We reviewed the medical records of all pediatric kidney recipients followed up in our pediatric nephrology department. Hypertension was defined as systolic and/or diastolic BP greater than the 95th percentile for age and sex, or as being on antihypertensive medication. BP control was defined as normotension while on antihypertensive medication.

RESULTS

The study population included 74 pediatric kidney recipients (median age 11 years). The prevalence of hypertension was found 77% before Tx, 82.4%, 71.7%, and 61% at 1, 5, and 10 years after Tx, respectively. Deceased donor Tx and pre-transplant hypertension on antihypertensive medication were significant risk factors for hypertension after kidney Tx over the follow-up period. BP control among patients on antihypertensive treatment was 16.7% before Tx, 43.8%, 66.7%, and 42.9% at 1, 5, and 10 years post-Tx, respectively. Hypertensive patients at 10 years post-Tx had 8.079 times higher hazard of graft loss compared to normotensives (95% CI 1.561-41.807, P < 0.05).

CONCLUSIONS

Hypertension remains a frequent complication in pediatric kidney recipients even years after kidney Tx. BP control by antihypertensive treatment is unsatisfactory in about half of the patients. The adverse effects of hypertension on graft survival may appear in the long-term.

Ambulatory Blood Pressure Monitoring and Echocardiographic Findings in Renal Transplant Recipients

Hypertension is common in renal transplant recipients (RTRs). Ambulatory blood pressure (BP) monitoring (ABPM) is important in diagnosing hypertension and diurnal BP variation. The authors set out to compare office BP and ABPM measurements to determine diurnal pattern and to evaluate echocardiographic findings in RTRs. ABPM and office BP measurements were compared in 87 RTRs. Echocardiographic evaluation was performed for each patient. The correlations between office and 24-hour ABPM were 0.275 for mean systolic BP (P=.011) and 0.260 for mean diastolic BP (P=.017). Only 36.8% had concordant hypertension between office BP and ABPM, with a masked hypertension rate of 16.1% and white-coat effect rate of 24.1%. Circadian BP patterns showed a higher proportion of nondippers (67.8%). Left ventricular mass index was increased in 21.8% of all recipients. There was a significant but weak correlation between office BP and ABPM.

Hypertension in children after renal transplantation

BACKGROUND

Hypertension (HT) is a common and serious complication following renal transplantation in children, and an important risk factor for cardiovascular morbidity and mortality. This study evaluated the clinical characteristics of HT in children after renal transplantation.

METHODS

Twenty-four children who were followed up at least 6 months after renal transplantation were enrolled in the study. From the clinical records, demographic and laboratory data, casual blood pressure (BP) measurement, ambulatory BP monitoring (ABPM), medication, and left ventricular mass index (LVMI) at echocardiogram were documented.

RESULTS

Mean age at time of transplantation was 12.6 ± 3.0 years and mean follow-up period was 19.6 ± 15.8 months. HT was detected in 21 children (87.5%) after renal transplantation. Twelve patients (50%) had HT both before and after transplantation and nine (38%) had HT only after transplantation. HT developed in 67% within the first week and in 95% within the first month. All hypertensive children had night-time HT and no child had isolated daytime HT. The efficacy of HT control was 42%. Median LVMI in patients with HT after renal transplantation was 42.3 g/m(2.7).

CONCLUSIONS

Severe HT, an important complication, was frequently seen in the early period after renal transplantation. Predominance of nocturnal HT and the lack of isolated daytime HT after transplantation underline the importance of ABPM. ABPM should be performed regularly in the first year after transplantation, not only for diagnosis but also for evaluation of HT control.

Pre-treatment considerations in childhood hypertension due to chronic kidney disease

Hypertension (HTN) develops very early in childhood chronic kidney disease (CKD). It is linked with rapid progression of kidney disease, increased morbidity and mortality hence the imperative to start anti-hypertensive medication when blood pressure (BP) is persistently > 90^th percentile for age, gender, and height in non-dialyzing hypertensive children with CKD. HTN pathomechanism in CKD is multifactorial and complexly interwoven. The patient with CKD-associated HTN needs to be carefully evaluated for co-morbidities that frequently alter the course of the disease as successful treatment of HTN in CKD goes beyond life style modification and anti-hypertensive therapy alone. Chronic anaemia, volume overload, endothelial dysfunction, arterial media calcification, and metabolic derangements like secondary hyperparathyroidism, hyperphosphataemia, and calcitriol deficiency are a few co-morbidities that may cause or worsen HTN in CKD. It is important to know if the HTN is caused or made worse by the toxic effects of medications like erythropoietin, cyclosporine, tacrolimus, corticosteroids and non-steroidal anti-inflammatory drugs. Poor treatment response may be due to any of these co-morbidities and medications. A satisfactory hypertensive CKD outcome, therefore, depends very much on identifying and managing these co-morbid conditions and HTN promoting medications promptly and appropriately. This review attempts to point attention to factors that may affect successful treatment of the hypertensive CKD child and how to attain the desired therapeutic BP target.

Treatment of hypertension in children with chronic kidney disease

Hypertension (HTN) is increasingly recognized as a common feature of pediatric chronic kidney disease (CKD). A growing body of evidence demonstrates that HTN is both underdiagnosed and undertreated in this population. The consequences of untreated HTN include adverse effects on CKD progression, markers of cardiovascular morbidity, and neurocognitive functioning. Consensus guidelines issued over the past decade have incorporated recent research on the consequences of HTN in recommendations for the diagnosis and treatment of HTN in pediatric CKD and include lower BP targets. Agents which target the renin-angiotensin-aldosterone system (RAAS) should be considered first-line therapy in CKD-associated HTN in children, though multiple medications may be required to achieve sufficient BP control.

Blood pressure profiles 5 to 10 years after transplant in pediatric solid organ recipients

Arterial hypertension is a major risk factor for cardiovascular disease after solid organ transplantation, emphasizing the need for blood pressure (BP) monitoring. The authors studied 24-hour ambulatory BP monitoring (ABPM) parameters (index, load, dipping) and their predictive value with regard to hypertension as well as correlations with graft function and metabolic parameters such as obesity and dyslipidemias. The ABPM profiles of 111 renal, 29 heart, and 13 liver transplant recipients were retrospectively analyzed 5 to 10 years after transplant (median 5.1 years). The BP profiles among the different transplant groups were similar. The BP index and load were abnormal especially at nighttime and the nocturnal BP dipping was often blunted (in 49% to 83% of the patients). The BP variables were found to be equally valued when assessing hypertension. BP load of 50% instead of 25% seems to be a more adequate cutoff value. The BP variables correlated poorly with the metabolic parameters and kidney function. Antihypertensive medication did not notably change the ABPM profile in renal transplant recipients. Hypertension, including nocturnal hypertension, is present in children receiving solid organ transplant, underlining the importance of use of ABPM in the follow-up of these patients.

Post-transplant hypertension in pediatric kidney transplant recipients

BACKGROUND

The aim of the study was to investigate the prevalence of post-transplant hypertension (HT) and to assess the blood pressure (BP) of transplanted children with possible risk factors.

METHODS

Office and ambulatory blood pressure measurements were performed for each patient.

RESULTS

Twenty-nine patients were included in the study, including 13 patients with newly diagnosed untreated HT according to the results of ambulatory blood pressure monitoring (ABPM). Fourteen patients were on antihypertensive medication, but only in five of these patients was the HT under control; nine patients receiving antihypertensive drugs had uncontrolled HT. Of the 29 patients, two had normotension without any antihypertensive drug(s). Standard deviation scores (SDS) of the nocturnal diastolic BP of the ABPM were positively correlated with the prednisolone dosage per kilogram (p = 0.013, r = 0.45) and negatively correlated with the time period after transplantation (p = 0.024, r = -0.41). Similarly, the SDS of the 24-h diastolic BP was positively correlated with the prednisolone dosage per kilogram (p = 0.006, r = 0.50) and negatively correlated with the time period after transplantation (p = 0.016, r = -0.44). Patients with alternate-day steroid treatment had lower nocturnal systolic (p = 0.016), nocturnal diastolic (p = 0.001) and 24-h diastolic (p = 0.008) SDS when compared to those receiving daily steroid medication.

CONCLUSION

The prevalence of HT among children after renal transplantation was high among our patient cohort, and steroids had direct impact on nocturnal and diastolic BP.

Pediatric transplantation: opportunities for pharmacogenomics and genomics

Heterogeneity is the rule among pediatric heart transplant recipients. Patients vary in age, size, organ maturity, immune system maturity and underlying disease etiology, which can all influence post-transplant outcomes. Overall, the survival of pediatric transplant recipients continues to improve and the goal remains long-term survival of the primary graft and mitigation of long-term complications and adverse events. The evolving fields of pharmacogenomics and genomics have the potential to revolutionize and personalize the care of pediatric transplant recipients, and although clinical validation in a pediatric cohort is lacking, many of these technologies are becoming more readily available. We discuss genotype-guided dosing of immunosuppressant medications and other commonly used medications after transplantation, the influence of donor and recipient genotype on risk of post-transplant complications, genotype-guided selection of therapies to treat complications, and the use of next-generation sequencing for noninvasive detection of graft rejection.

Ambulatory blood pressure monitoring in pediatric renal transplantation

Hypertension is a common and serious complication after renal transplantation. It is an important risk factor for graft loss and adverse cardiovascular outcomes. Blood pressure (BP) in transplanted children should be measured not only by clinic BP (cBP) measurement, but also by ambulatory blood pressure monitoring (ABPM), because ABPM has distinct advantages over cBP, specifically the ability to reveal nocturnal, masked or white-coat hypertension. These types of hypertension are common in transplanted children (nocturnal hypertension 36-71 %, masked hypertension 24-45 %). It may also reveal uncontrolled hypertension in treated children, thereby improving control of hypertension. Regular use of ABPM and ABPM-guided therapy of hypertension may help to decrease cardiovascular and renal target organ damage in transplanted children. Therefore, ABPM should be routinely performed in all transplanted children at least once a year, regardless of the values of cBP.

Systemic arterial hypertension in children following renal transplantation: prevalence and risk factors

BACKGROUND

Control of blood pressure (BP) following renal transplantation may improve allograft and patient survival. Our aims were (i) to describe the distribution of BP and the prevalence of systolic and/or diastolic hypertension in children over the first 5 years following renal transplantation and (ii) to evaluate clinical risk factors and centre-specific factors associated with hypertension in this population.

METHODS

We conducted a retrospective case note review of all current paediatric kidney transplant patients in the UK, with data collected at 6 months, 1, 2 and 5 years following transplantation in subjects with hypertension (systolic and/or diastolic BP > 95th > ) and non-hypertensive subjects BP ≤ 95th > .

RESULTS

In total, 27.3% (117/428), 27.6% (118/428), 26.0% (95/365) and 25.6% (50/195) of the patients were hypertensive (systolic and/or diastolic BP > 95th > ) at 6 months, 1, 2 and 5 years following transplantation, respectively. A total of 58.4% of the patients at 6 months, 52.8% at 1 year, 48.2% at 2 years and 48.2% at 5 years were receiving anti-hypertensive therapy, of whom 31.6-36.6% remained hypertensive. When subjects were identified as being hypertensive, on anti-hypertensive medication or had untreated hypertension (systolic and/or diastolic BP > 95th > ), 66.4, 61.0, 56.4 and 55.9% of patients were hypertensive at 6 months, 1, 2 and 5 years, respectively. In a multivariate model, odds ratios for systolic hypertension were 4.16 (deceased versus living donor), 2.65 (lowest versus highest quartile of height z-score) and 2.07 (if on anti-hypertensive; yes versus no). There was significant variation in prevalent rates of hypertension between centres (P < 0.0001) that remained significant (P = 0.003) after adjustment for all the factors in the multivariate model.

CONCLUSIONS

Control of BP after kidney transplantation remains sub-optimal in paediatric centres in the UK. Just over 25% of patients remain hypertensive 5 years following transplantation. Significant differences between centres remain unexplained and may reflect differences in assessment and management of hypertension.

Demographics of blood pressure and hypertension in children on renal replacement therapy in Europe

Hypertension is a well-known complication in children on renal replacement therapy and an important risk factor for cardiovascular disease in later life. In order to define the prevalence of and risk factors for hypertension among children, we enrolled 3337 pediatric patients from 15 countries in the ESPN/ERA-EDTA Registry of whom 464 were on hemodialysis, 851 on peritoneal dialysis, and 2023 had received a renal allograft. Hypertension was defined as either systolic or diastolic blood pressures in the 95th percentile or greater for age, height, and gender or use of antihypertensive medication. Analyses were adjusted for age, gender, duration, and modality of renal replacement therapy. In 10 countries in which information on the use of antihypertensive medication was available, hypertension was present in over two-thirds of hemodialysis, peritoneal dialysis, or transplant patients. Blood pressure values above the 95th percentile were significantly more prevalent in very young patients (under 3 years) compared to 13- to 17-year olds (odds ratio 2.47), during the first year compared to over 5 years of renal replacement therapy (odds ratio 1.80), and in patients on hemodialysis compared to transplant recipients or those on peritoneal dialysis (odds ratios of 2.48 and 1.59, respectively). Over time, mean blood pressures decreased in both hemodialysis and transplant patients, but not in peritoneal dialysis patients. Hence, our findings highlight the extent of the problem of hypertension in children with end-stage renal disease in Europe.

Blood pressure profile in renal transplant recipients and its relation to diastolic function: tissue Doppler echocardiographic study

Hypertension is a common complication after renal transplantation and is associated with increased risk of cardiovascular disease. The aim of the current study was to investigate the diurnal blood pressure pattern and its relation to structural and functional cardiac changes in renal transplant recipients. Sixty-six stable renal transplant patients (34 female, 32 male), aged 7 to 25 years (mean 17.4±4.3 years) were enrolled in this study. Cardiac function assessed by tissue Doppler echocardiography and blood pressure measurement performed using both the ambulatory and the casual method. Hypertension was demonstrated in 57% of recipients by the casual method and in 75.7% by ambulatory blood pressure monitoring (ABPM). The efficacy of BP control among patients on antihypertensive drugs was 60%. The prevalence of non-dipping was 73%. There was significant inverse correlation between systolic or diastolic day-time or night-time BP index and post-transplant duration (p<0.001, r=-0.386), but no correlation between ABP parameters and BMI, gender, and eGFR. There was a significant relationship between all ABP parameters and left ventricular mass index (LVMI) (p=0.025-0.007, r=0.28-0.38). LVMI was significantly higher in hypertensive than in normotensive cases (p=0.034). There was no difference in diastolic function between hypertensive and normotensive patients or between patients with and without left ventricular hypertrophy (LVH). In conclusion, our study showed the advantage of ABPM over the casual method of diagnosis of hypertension. LVH is common in transplant patients and is likely associated with arterial hypertension. Hypertension and LVH cannot differentiate transplant patients with diastolic malfunction.

Cardiorespiratory fitness is a marker of cardiovascular health in renal transplanted children

Children with renal transplants (TX) are at increased risk of cardiovascular (CV) disease. Study objectives were to assess the level of cardiorespiratory fitness (CR fitness) and daily physical activity (PA) in renal TX children and adolescents in relation to traditional cardiovascular risk factors. Laboratory testing included assessment of CR fitness by treadmill exercise testing (VO(2peak)), 24-h ambulatory blood-pressure (ABPM) measurement, oral glucose tolerance test (OGTT), anthropometrics and measurement of lipid levels. PA was self-reported by questionnaire. Twenty-two TX patients with a median (range) age 14.5 (9-18) years were tested. Median V0(2peak) was 66% (36-97) of the expected values compared with controls. Nineteen (86%) children reported <60 min of daily moderate to vigorous physical activity (MVPA). Sixteen (73%) were hypertensive and 8 (34%) were overweight or obese. Four children fulfilled the criteria for a metabolic syndrome. Children with at least 2 of the 3 metabolic risk factors (hypertension, overweight, and glucose intolerance, n=7) achieved significantly lower VO(2peak) compared with those with one or none of these factors (median V0(2peak) 45% and 73% of the expected values respectively, p=0.003). Renal TX children and adolescents have severely impaired CR fitness and PA. Reduced CR fitness was associated with the clustering of CV risk factors. Routine counseling for increased PA is strongly recommended.

Longitudinal relations between obesity and hypertension following pediatric renal transplantation

Obesity and hypertension frequently complicate renal transplantation (RTxp). The objective was to assess relations among obesity, hypertension, and glucocorticoids in pediatric RTxp recipients. A retrospective cohort study was carried out in 141 RTxp recipients, 2-21 years of age, with >or=12 months of follow-up. Body mass index Z-score (BMI-Z), systolic and diastolic blood pressure Z-scores (SBP-Z and DBP-Z), and medications at 1, 3, 6, and 12 months and annually thereafter were recorded. Quasi-least squares regression analysis was used. The prevalence of obesity (BMI>or=95th percentile) increased from 13% at baseline to >30% from 3 months onward. Greater glucocorticoid exposure (mg/kg/day) was associated with greater increases in BMI-Z (p<0.001). This association was greater in males, younger recipients, and those with lower baseline BMI-Z (all interactions p<0.02). The prevalence of systolic hypertension (SBP>or=95th percentile) was 73% at 1 month and >or=40% at all follow-up visits. Greater glucocorticoid exposure (p<0.001) and increases in BMI-Z (p=0.005) were independent determinants of SBP-Z over time. Cyclosporine (versus tacrolimus) was independently associated with greater SBP-Z and DBP-Z (p=0.001). Sustained obesity and hypertension frequently complicated pediatric RTxp. Obesity was an independent determinant of systolic hypertension. Strategies are needed to prevent obesity and its impact on hypertension, cardiovascular disease, and allograft survival.

Masked hypertension and hidden uncontrolled hypertension after renal transplantation

Arterial hypertension is a risk factor affecting graft function in pediatric kidney transplants. Recent pediatric studies reported a high prevalence of hypertension, especially nocturnal hypertension in this population. Data regarding the prevalence of masked hypertension in pediatric patients with kidney transplants are still scarce. The aim of this cross-sectional study was to assess the prevalence of masked and hidden uncontrolled hypertension after renal transplantation. A total of 41 patients (25 males) with stable functioning renal graft were included in the study. Their median age was 14.5 years with the median interval since transplantation of 2.5 years (range 0.3 to 20.6). Spacelabs 90207 was used to measure ambulatory blood pressure (BP) during a 24-h period. Ambulatory hypertension was defined as mean systolic and/or diastolic BP index at day-time or nighttime >or=1. Masked hypertension was defined as normal office BP but daytime ambulatory hypertension in patients without antihypertensive medications. Hidden uncontrolled hypertension was defined as daytime ambulatory hypertension undetected by office BP measurements in treated patients. Antihypertensive medications were prescribed to 58%. Prevalence of nocturnal hypertension was 68%. On the basis of combination of office and ABPM masked hypertension and hidden uncontrolled hypertension was detected in 24% and 21% of the study population, respectively. Regular use of ambulatory blood pressure monitoring in transplanted patients enables detection of masked and hidden uncontrolled hypertension.

Hypertension after pediatric cardiac transplantation: detection, etiology, implications and management

While it may rescue children with end-stage heart failure from impending catastrophe, cardiac transplantation leaves 50-70% of pediatric recipients with new-onset hypertension. Given the unique vulnerability of the heart and kidneys in these children, we can expect long-term uncontrolled hypertension to shorten both graft and patient survival. In this review we discuss the multi-factorial etiology of post-transplant hypertension, highlighting current uncertainties and emphasizing mechanisms specific to cardiac recipients. We consider the optimal means of monitoring BP and in particular, the advantages of 24 h-ABP over intermittent clinic measurements. We also review BP treatment after cardiac transplantation, drawing attention to specific cautions appropriate when prescribing antihypertensive agents in these circumstances.

Adverse effects of immunosuppression in pediatric solid organ transplantation

Solid organ transplantation is a life-saving treatment for end-stage organ failure in children. Immunosuppressant medications are used to prevent rejection of the organ transplant. However, these medications are associated with significant adverse effects that impact growth and development, quality of life (QOL), and sometimes long-term survival after transplantation. Adverse effects can differ between the immunosuppressants, but many result from the overall state of immunosuppression. Strategies to manage immunosuppressant adverse effects often involve minimizing exposure to the drugs while balancing the risk for rejection. Early recognition of immunosuppressant adverse effects may help to reduce morbidities associated with solid organ transplantation, improve QOL, and possibly increase overall patient survival.

Ocular complications in children and adolescents following renal transplantation

Ocular complications after renal transplantation are common in adults. Nevertheless, data regarding these complications in children are insufficient. The purpose of the present study was to assess ocular morbidity in pediatric renal graft recipients. A retrospective observational study of 71 patients aged 11.2 +/- 5.5 yr was conducted. Mean duration of follow-up was 5.6 +/- 3.5 yr. A total of 16 ocular complications were found in 12 (17%) of the patients. Three patients suffered from more than one complication. Cataract was the most common finding (six patients, 8.4%) followed by swollen disk and hypertensive retinopathy in four patients (5.7%) each and increased intra-ocular pressure in two patients (3%). Mean time interval between transplantation and occurrence of first abnormal ocular finding was 37 +/- 34.5 months. The follow-up time was significantly longer in patients with ophthalmological problems than in those without complications (7.8 yr vs. 5.2 yr, p < 0.02). No statistically significant association was found between the occurrence of ocular complications and the age of the patients at transplantation, donor source, duration of dialysis prior to transplantation, previous corticosteroid therapy or presence of acute rejection episodes. The results of the study point to the importance of regular concurrent ophthalmological follow-up in pediatric renal graft recipients to reduce/prevent ocular morbidity.

Management of arterial hypertension occurring early after living donor liver transplantation in children: report of three cases and review of the literature

Three pediatric patients with hypertension occurring early after liver transplantation are reviewed. The patients were all female, and underwent living donor liver transplantation at the age of 9 years, 1 month, and 7 months. The etiology of liver disease was cirrhosis due to biliary atresia in two patients and fulminant hepatitis in one patient. Antihypertensive therapy with calcium channel blocker alone was not effective. Blood pressure was eventually controlled after the administration of a beta-adrenergic blocker in addition to the calcium channel blocker to all patients. No end-organ damage was observed, except that two patients developed temporary left ventricular hypertrophy.

Hypertension after renal transplantation

Hypertension is a common and serious complication after renal transplantation. It is an important risk factor for graft loss and morbidity and mortality of transplanted children. The etiology of posttransplant hypertension is multifactorial: native kidneys, immunosuppressive therapy, renal-graft artery stenosis, and chronic allograft nephropathy are the most common causes. Blood pressure (BP) in transplanted children should be measured not only by casual BP (CBP) measurement but also regularly by ambulatory BP monitoring (ABPM). The prevalence of posttransplant hypertension ranges between 60% and 90% depending on the method of BP measurement and definition. Left ventricular hypertrophy is a frequent type of end-organ damage in hypertensive children after transplantation (50-80%). All classes of antihypertensive drugs can be used in the treatment of posttransplant hypertension. Hypertension control in transplanted children is poor; only 20-50% of treated children reach normal BP. The reason for this poor control seems to be inadequate antihypertensive therapy, which can be improved by increasing the number of antihypertensive drugs. Improved hypertension control leads to improved long-term graft and patient survival in adults. In children, there is a great potential for antihypertensive treatment that could also result in improved graft and patient survival.

Blood pressure control in hypertensive pediatric renal transplants: role of repeated ABPM following transplantation

BACKGROUND

Hypertension in pediatric renal transplants is a widespread condition associated with high mortality risk in early adult life. Ambulatory blood pressure monitoring (ABPM) was found to be superior to office blood pressure (BP) in identifying true hypertensive and responders to treatment. The aim of this study was to investigate the role of repeated ABPM, performed at yearly intervals following transplantation, in the assessment and decision-making processes of post-transplant hypertension.

METHODS

Thirty-seven recipients (23 males; aged 10.5 +/- 4.3 years) who were followed for 4.3 +/- 2.2 years (range 2-9) after transplantation were eligible for analysis. The mean follow-up time between the baseline (1 year post-transplantation) and the most recent ABPM examination was 3.3 +/- 2.2 years (range 1-8).

RESULTS

Throughout the follow-up period, antihypertensive therapy was either started or intensified in 27 recipients. These interventions were decided based on ABPM results obtained on 40 of 44 occasions. At last follow-up, 24 of 29 treated hypertensive recipients displayed controlled BP. This figure was significantly higher compared to our historical hypertensive control recipients in whom ABPM was applied for the first time in treatment at 6 +/- 3.3 years (range 2-15) after transplantation, while therapeutic decisions were driven by office BP measurements (95 % confidence interval (95% CI) for the difference between proportions (80.6-32 %) 36-60 %, P = 0.001).

CONCLUSIONS

Our study shows that, in a population with high risk for hypertension, repeated ABPM may significantly help to improve BP control.

Therapeutic strategies to slow chronic kidney disease progression

Childhood chronic kidney disease commonly progresses toward end-stage renal failure, largely independent of the underlying disorder, once a critical impairment of renal function has occurred. Hypertension and proteinuria are the most important independent risk factors for renal disease progression. Therefore, current therapeutic strategies to prevent progression aim at controlling blood pressure and reducing urinary protein excretion. Renin-angiotensin-system (RAS) antagonists preserve kidney function not only by lowering blood pressure but also by their antiproteinuric, antifibrotic, and anti-inflammatory properties. Intensified blood pressure control, probably aiming for a target blood pressure below the 75th percentile, may exert additional renoprotective effects. Other factors contributing in a multifactorial manner to renal disease progression include dyslipidemia, anemia, and disorders of mineral metabolism. Measures to preserve renal function should therefore also comprise the maintenance of hemoglobin, serum lipid, and calcium-phosphorus ion product levels in the normal range.

Improved control of hypertension in children after renal transplantation: results of a two-yr interventional trial

Hypertension is a frequent complication in children after renal transplantation and the control of post-transplant hypertension is unsatisfactorily low. The aim of this prospective interventional study was to improve the control of hypertension in children after renal transplantation. Thirty-six children fulfilled the inclusion criteria (> or =6 months after transplantation and no acute rejection in the last three months). BP was measured using ABPM. Hypertension was defined as mean ambulatory BP > or =95th-centile for healthy children and/or using antihypertensive drugs. The study intervention consisted of using intensified antihypertensive drug therapy - in children with uncontrolled hypertension (i.e., mean ambulatory BP was > or =95th centile in treated children), antihypertensive therapy was intensified by adding new antihypertensive drugs to reach goal BP <95th centile. ABPM was repeated after 12 and 24 months. Daytime BP did not change significantly after 12 or 24 months. Night-time BP decreased from 1.57 +/- 1.33 to 0.88 +/- 0.84 SDS for systolic and from 1.10 +/- 1.51 to 0.35 +/- 1.18 SDS for diastolic BP after 24 months (p < 0.05). The number of antihypertensive drugs increased from 2.1 +/- 0.9 to 2.7 +/- 0.8 drugs per patient (p < 0.05), this was especially seen with the use of ACE-inhibitors (increase from 19% to 40% of children, p < 0.05). In conclusion, this interventional trial demonstrated that, in children after renal transplantation, the control of hypertension, especially at night-time, can be improved by increasing the number of antihypertensive drugs, especially ACE-inhibitors.

ABPM vs office blood pressure to define blood pressure control in treated hypertensive paediatric renal transplant recipients

While 24-h ambulatory blood pressure monitoring (ABPM) is an established tool for monitoring antihypertensive therapy in adults, data in children are scarce. We retrospectively analysed whether office blood pressure (BP) is reliable for the diagnosis of BP control in 26 treated hypertensive paediatric renal transplants. Controlled office BP was defined as the mean of three replicate systolic and diastolic BP recordings less than or equal to the 95th age-, sex- and height-matched percentile on the three-outpatient visits closest to ABPM. Controlled ABPM was defined as systolic and diastolic daytime BP < or =95th distribution adjusted height- and sex-related percentile of the adapted ABPM reference. Eight recipients (30%) with controlled office BP were in fact categorized as having non-controlled BP by ABPM criteria. Overall, when office BP and ABPM were compared using the Bland and Altman method, the 95% limits of agreement between office and daytime values ranged from -12.6 to 34.1 mmHg for systolic and -23.9 to 31.7 mmHg for diastolic BP, and the mean difference was 10.7 and 3.9 mmHg respectively. Office readings miss a substantial number of recipients who are hypertensive by ABPM criteria. Undertreatment of hypertension could be avoided if ABPM is applied as an adjunct to office readings.