Ambulatory Blood Pressure Phenotypes in Children and Adolescents

Abstract

HomeHypertensionVol. 75, No. 3Ambulatory Blood Pressure Phenotypes in Children and Adolescents Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBAmbulatory Blood Pressure Phenotypes in Children and AdolescentsDefinitions and Subclinical Organ Damage Stella Stabouli and Vasilios Kotsis Stella StabouliStella Stabouli Correspondence to Stella Stabouli, MD, PhD, 1st Pediatric Department, Aristotle University Thessaloniki, Hippokratio Hospital, 49 Konstantinoupoleos Str, 54642, Greece. Email E-mail Address: [email protected] From the 1st Pediatric Department, Aristotle University Thessaloniki, Hippocratio Hospital, Greece; and Hypertension-24h ABPM ESH Center of Excellence, 3rd Department of Medicine, Aristotle University of Thessaloniki, Papageorgiou Hospital, Greece. Search for more papers by this author and Vasilios KotsisVasilios Kotsis From the 1st Pediatric Department, Aristotle University Thessaloniki, Hippocratio Hospital, Greece; and Hypertension-24h ABPM ESH Center of Excellence, 3rd Department of Medicine, Aristotle University of Thessaloniki, Papageorgiou Hospital, Greece. Search for more papers by this author Originally published30 Dec 2019https://doi.org/10.1161/HYPERTENSIONAHA.119.14278Hypertension. 2020;75:615–617This article is a commentary on the followingHemodynamic Patterns and Target Organ Damage in Adolescents With Ambulatory PrehypertensionOther version(s) of this articleYou are viewing the most recent version of this article. Previous versions: December 30, 2019: Ahead of Print See related article, pp 826–834Hypertension in children and adolescents is emerging as an important health issue with the recently published guidelines focusing on early detection and management of high blood pressure (BP) in this age group.1 The use of ambulatory blood pressure monitoring (ABPM) for the diagnosis of hypertension has been reinforced based on increasing evidence on the clinical significance of ambulatory BP phenotypes in the general hypertensive pediatric population, as well as in the high-risk groups for future cardiovascular morbidity. The definition of ambulatory BP phenotypes differs among European and American pediatric guidelines. The European guidelines use only mean BP levels, while the American guidelines use a combination of mean BP levels and BP load.1,2 These phenotypes include sustained normotension and hypertension, when both ABPM and office BP are in agreement, but also those with ABPM and office BP discrepancies, white coat and masked hypertension. In the American Heart Association 2014 staging schema for children and adolescents, a prehypertensive ambulatory BP phenotype is also included, defined as office BP in the 90th to <95th percentile, mean ambulatory BP <95th percentile, and BP load ≥25%.2 BP load has not been used in adult definitions. In the pediatric population is defined as the percentage of readings ≥95th percentile for sex and age or height of the individual child or adolescent.In the current issue of Hypertension, Obrycki et al3 demonstrated similar indices of subclinical hypertension-induced target organ damage in children with both ambulatory prehypertension and sustained hypertension. Using the American Heart Association 2014 classification, these groups included patients with a BP load of at least 25%. Furthermore, by the study design, only children and adolescents with high central systolic BP were included in the sustained hypertension group. With regard to ambulatory BP classification, these findings may have important implications. First, they support previous evidence that the 95th percentile based on office or ambulatory BP statistical distribution may not be the optimal threshold with regard to cardiovascular risk stratification. Second, a BP load >25% may be associated with increased levels of hypertensive target organ indices. The inclusion of BP load in the definition of ambulatory hypertension has been investigated in several studies showing association of left ventricular hypertrophy both with mean ambulatory BP values and BP loads. Only one study provided head to head comparison of mean BP levels severity and BP loads. The best prediction of left ventricular hypertrophy was found for the combination of mean 24-hour systolic BP at the 95th percentile and 24-hour systolic BP load >50%. However, the sensitivity and specificity were low (58% and 67%, respectively).4 Third, the clinical significance of central systolic BP is rather unclear as ambulatory prehypertensives, despite lower, within normal limits, levels of central systolic BP compared with hypertensives presented similar subclinical target organ damage indices.In the case of children and adolescents, BP thresholds are derived from the statistical distribution of BP in healthy children and adolescents and BP levels ≥95th percentile of the normal distribution has been considered as the hypertensive range. The predictive value of these thresholds has not been validated against hard cardiovascular outcomes because of the remoteness of cardiovascular events in children and adolescents. However, cohort studies using lower office BP values in childhood (usually office BP at the 90th to <95th percentile) demonstrated associations with adult intermediate cardiovascular end points, including left ventricular hypertrophy, carotid intima media thickness, and pulse wave velocity.5 The mean ambulatory BP 95th percentile threshold may discriminate children with increased risk for left ventricular mass, both masked and sustained hypertensives, in referral pediatric patients.6,7 The mean ambulatory BP 90th percentile has also been demonstrated to associate with increased left ventricular mass index, and the children and adolescents with ambulatory BP between the 90th and <95th percentile (reflecting the BP percentile range previously used to define office prehypertension thereafter referred as high normal BP) were found to present similar prevalence of left ventricular hypertrophy with sustained hypertensives.8The American Heart Association 2014 BP classification has several gray zones and a number of children may remain unclassified previously reported to be those with BP load ≥25% despite normal office and ambulatory BP. The base for this classification is office BP with combinations of ABPM parameters, mean ambulatory BP, or BP load. Office BP values in the high normal BP range include a number of children with BP loads ≥25%, who could have increased cardiovascular risk. However, the unanswered question is the exact levels of mean ambulatory BP that increase risk in these children; and if there is a difference compared with those with BP load <25% (another unclassified group by the American Heart Association 2014 classification). In other words, which are the mean levels of ambulatory BP in children with office BP in the high normal BP range that predict target organ damage and does BP load really add to the prediction?Beyond ambulatory BP abnormalities expressed as increased BP load, children with high normal office BP seem to have increased central systolic BP and BMI z score with high prevalence of both obesity and overweight compared with office normotensives.3 Hyperkinetic status could be the underlying pathogenetic mechanism of increasing office peripheral and central systolic BP. One issue that merits consideration in all studies in children and adolescents referred for hypertension is the presence of overweight and obesity. BP levels in the high normal BP category presented consistently higher prevalence among overweight and obese adolescents in the National Health and Nutrition Examination Surveys over the last 25 years.9 The high prevalence of obesity may be an important confounder to the pathogenesis of left ventricular hypertrophy independent of BP. Observational studies in children with primary hypertension also showed that lifestyle modification is an independent predictor of changes in cardiac geometry.10Finally, another critical question is whether office BP could guide initial therapeutic decisions in children and adolescents. Office BP levels in the high normal range have been associated with increased risk of masked hypertension.1,7 Furthermore, Obrycki et al3 showed that office BP levels in those having ambulatory prehypertension may have clinical significance, as they associate with subclinical target organ damage intermediate between those with office normotension and hypertension and similar to hypertensives. Thus, office BP matters even when mean ambulatory BP is normal. The crucial role of ambulatory BP provides additional phenotype classification and informs on hypertension management. In conclusion, it could be recommended that children with office high normal BP should undergo meticulous clinical evaluation including ABPM, assessment of cardiovascular risk, and possibly assessment of subclinical target organ damage in children with obesity or multiple cardiovascular risk factors (Figure).Download figureDownload PowerPointFigure. Algorithm for the evaluation of children and adolescents with office high normal blood pressure (BP). When mean ambulatory BP is below the 95th percentile (pc), cardiovascular (CV) risk could guide patient evaluation. Further evidence is needed to guide decision for follow up or CV risk assessment (dotted arrows) in the unclassified group by the American Heart Association 2014 with normal mean ambulatory BP and BP load <25% (gray boxes). ABPM indicates ambulatory blood pressure monitoring.Sources of FundingNone.DisclosuresNone.FootnotesThe opinions expressed in this article are not necessarily those of the American Heart Association.Correspondence to Stella Stabouli, MD, PhD, 1st Pediatric Department, Aristotle University Thessaloniki, Hippokratio Hospital, 49 Konstantinoupoleos Str, 54642, Greece. Email [email protected]gr