Blood Pressure After Cardiac Transplantation in Childhood

Anti-hypertensive treatment in the immediate post-operative period and 1 year after pediatric heart transplantation

Hypertension is a known complication of pediatric heart transplantation. We sought to identify factors associated with anti-hypertensive use in pediatric heart transplant recipients immediately post-transplant and oral anti-hypertensive use at discharge and 1-year post-transplant. Retrospective chart review was conducted of patients ≤18 years who underwent heart transplantation at two major heart transplant centers between August 1, 2009 and December 31, 2017 with ≥1-year follow-up. Exclusion criteria included re-transplant, multi-organ recipients, survival <1 year, and comorbidities associated with hypertension. Anti-hypertensive use was recorded during initial ICU stay, at discharge, and 1-year post-transplant. Univariate and multivariate analyses determined associations of demographic and diagnostic factors and need for anti-hypertensives. There were 188 patients that met inclusion criteria. Anti-hypertensive infusions were required in the ICU post-transplant in 46 patients (24.5%) for a median of 3 days (1-21 days). Oral anti-hypertensives were required in 58 patients (30.9%) at discharge and 1-year post-transplant. Anti-hypertensive infusion in the ICU post-transplant was associated with donor-to-recipient weight ratio. Oral anti-hypertensive use at discharge was associated with weight ratio and pretransplant VAD use, and at 1-year, post-transplant was associated with age at transplant, steroid use at discharge, and oral anti-hypertensive use at discharge. Hypertension is common immediately following and 1-year post-transplant. Weight ratio was the only independent predictor of anti-hypertensive use in the early post-transplant period, whereas VAD use was also associated with anti-hypertensive use at discharge. Anti-hypertensive use 1-year post-transplant was not associated with those factors, but rather with age at transplant and steroid use.

Ambulatory Blood Pressure Monitoring in Pediatrics

PURPOSE OF REVIEW

This is a review of ambulatory blood pressure monitoring (ABPM) use in pediatrics, summarizing current knowledge and uses of ABPM.

RECENT FINDINGS

Updated guidelines from the American Academy of Pediatrics have emphasized the value of ABPM. ABPM is necessary to diagnose white coat hypertension, masked hypertension, and nocturnal hypertension associated with specific conditions. There is growing evidence that ABPM may be useful in these populations. ABPM has been demonstrated to be more predictive of end-organ damage in pediatric hypertension compared to office blood pressure. ABPM is an important tool in the diagnosis and management of pediatric hypertension. Routine use of ABPM could potentially prevent early cardiovascular morbidity and mortality in a wide variety of populations.

Innovative multi-site photoplethysmography measurement and analysis demonstrating increased arterial stiffness in paediatric heart transplant recipients

OBJECTIVE

It has been documented that heart transplantation in children is often complicated by arterial hypertension and increased arterial stiffness. We use innovative multi-site photoplethysmography (MPPG) pulse measurement and analysis technology to assess changes in arterial stiffness in paediatric heart transplant recipients (HTRs) in comparison with healthy control (HC) children.

APPROACH

A group of 20 HTRs (median age 13.5 years, eight male) were compared to an overall age- and gender-matched group of 161 HCs (median age 11.6 years, 74 male). Peripheral pulse was recorded bilaterally using MPPG at the ear lobe, index finger and great toe sites, along with an electrocardiogram cardiac timing reference. Segmental pulse arrival times between peripheral sites (finger-ear, PATf-e; toe-finger, PATt-f; and toe-ear PATt-e) were calculated as arterial stiffness measures, and differences between subject groups were tested using multivariate analysis. Normalised ear, finger and toe pulse shapes were also studied and compared between groups.

MAIN RESULTS

After correction for heart rate and diastolic and mean arterial blood pressures, the HTR group was found to have significantly lower segmental PATt-e and PATt-f measurements, with median values of 150 ms versus 172 ms in the HC group (p  =  0.02), and 104 ms versus 118 ms in the HC group (p  =  0.01), respectively, consistent with increased arterial stiffness in the patient group. The normalised ear, finger and toe sites showed only a mild elongation in each pulse rise time for the transplant group.

SIGNIFICANCE

This study shows that innovative and easy-to-do MPPG gives further evidence for increased arterial stiffness in children who have undergone successful cardiac transplantation.

The Use of Ambulatory Blood Pressure Monitoring As Standard of Care in Pediatrics

Hypertension (HTN) is a significant global health problem, responsible for 7.5 million deaths each year worldwide. The prevalence of HTN is increasing in the pediatric population likely attributed to the increase in childhood obesity. Recent work has also shown that blood pressure (BP) tends to track from childhood to adulthood including BP-related target organ damage. In the last 25-30 years, pediatric use of ambulatory blood pressure monitoring (ABPM) has been expanding mainly in the setting of initial elevated BP measurement evaluation, HTN therapy efficacy follow-up, and renal disease. However, there are many clinical areas where ABPM could potentially be used but is currently underutilized. This review summarizes the current knowledge and the uses of pediatric ABPM and explores clinical areas where it can be very useful both to detect HTN and its longitudinal follow-up. And thus, ABPM could serve as a critical tool to potentially prevent early cardiovascular mortality and morbidity in wide variety of populations. With solid data to support ABPM's superiority over clinic BP measurements and these clinical areas for its expansion, ABPM should now be part of standard of care in BP evaluation and management in pediatrics.

Practice recommendations for the monitoring of renal function in pediatric non-renal organ transplant recipients

The management of non-renal pediatric solid organ transplant recipients has become complex over the last decade with innovations in immunosuppression and surgical techniques. Post-transplantation follow-up is essential to ensure that children have functioning allografts for as long as possible. CKD is highly prevalent in these patients, often under recognized, and has a profound impact on patient survival. These practice recommendations focus on the early detection and management of hypertension, proteinuria, and renal dysfunction in non-renal pediatric solid organ transplant recipients. We present seven practice recommendations. Renal function should be monitored regularly in organ transplant recipients, utilizing assessment of serum creatinine and cystatin C. GFR should be calculated using the new Schwartz formula. Transplant physicians should also monitor blood pressure using automated oscillometric devices and confirm repeated abnormal measures with manual blood pressure readings and ambulatory 24-h blood pressure monitoring. Proteinuria and microalbuminuria should also be assessed regularly. Referrals to a pediatric nephrologist should be made for non-renal organ transplant recipients with repeated blood pressures >95th percentile using the Fourth Task Force reference intervals, microalbumin/creatinine ratio >32.5 mg/g (3.7 mg/mmol) creatinine on repeated testing and/or GFR <90 mL/min/1.73 m(2) .

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.

Heart rate variability arterial hypertension in young heart-transplanted recipients: association progression of cardiac allograft vasculopathy?

Hypertension and reduced HRV are frequent in heart-transplanted recipients. We studied 26 young recipients to investigate the relationship between BP and HRV during simultaneous 24-h monitoring. Presence of CAV was considered. All HRV measures were significantly lower than normal values. Significant correlations were found between mean daytime systolic BP and the rMSSD (p = 0.04), and mean daytime DBP and SDANN for all 5-min segments (p = 0.03) and between rMSSD and mean nighttime DBP (p = 0.03). Four patients were hypertensive during daytime, seven had a reduced nocturnal fall and two had a nocturnal rise in BP. Eight patients showed severe CAV grade (grade IV) on the Stanford scale, 13 moderate (grade III) and five mild (grade I-II). After a follow-up time of 30 months, four of the 13 patients (30%) with CAV grade III showed an increase to grade IV and all showed abnormalities of both HRV and ABPM patterns. The relationship between HRV abnormalities and arterial hypertension and CAV should be further explored.

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.

Ambulatory blood pressure monitoring: what a pediatrician should know

PURPOSE OF REVIEW

Ambulatory blood pressure monitoring is a useful tool for the evaluation and management of hypertension in children and adolescents. This review provides a basic overview of ambulatory blood pressure monitoring and summarizes the most recent available knowledge regarding its use in the pediatric population.

RECENT FINDINGS

Evaluation and validation of ambulatory blood pressure monitoring equipment in children remains limited, although advances in the interpretation of results for this age group have been reported specifically in the area of circadian (24 h) and ultradian (<24 h) variability. Blood pressure is a dynamic phenomenon that varies not only with time but also with changing patient and environmental circumstances. Growing evidence regarding conditions identified when this variability is considered, specifically white coat and masked hypertension, suggests that office blood pressure measurement may not be a sufficient screening test for hypertension-related target-organ damage.

SUMMARY

Information regarding ambulatory blood pressure monitoring use in children is increasing, although due to its limitations and expense, it remains a tool primarily utilized by the pediatric sub-specialist.

Heart transplantation in pediatric age

Heart transplantation, formerly the final option for terminally ill children, has now become the treatment of choice for a number of serious acquired or congenital cardiac conditions, which cannot be treated conservatively. Nevertheless, several problems remain unsolved. First of all the shortage of donors, mainly in the first months and years of life, which has become more and more significant with time, regardless of the country, religious belief or culture of the people. Secondly, the long-term impact of immunosuppression in a developing organism, and its possible inter-relation with the primary disorder, which leads to intractable heart failure. Whether a heart transplant is a cure or an ongoing disease for both the child and the family is another matter of concern. These and other topics are covered in this article.

Immunosuppression in pediatric solid organ transplantation: opportunities, risks, and management

The pediatric transplant community stands at a time of unprecedented choice of immunosuppressive agents - and with a legacy of morbidity from those agents used in the previous two decades. This review considers the clinical utility and side-effect profiles of immunosuppressants used widely in current practice (e.g., glucocorticoids, azathioprine, ciclosporin, tacrolimus, mycophenolate, and sirolimus) and those agents which are in increasing use or in evaluation (e.g., IL-2 receptor antibodies, everolimus, FTY720, LEA29Y, and deoxyspergualin). Further consideration is given to the wider drug interactions likely during the use of new immunosuppressant regimens and to our growing awareness of the influences of genetic heterogeneity on drug efficacy and handling. Finally, we consider the new demands being placed on the use of drug monitoring to regulate dosage of this new repertoire of immunosuppressants.