Twenty-four-hour ambulatory central blood pressure in adolescents and young adults: association with peripheral blood pressure and preclinical organ damage

Differences between brachial and aortic blood pressure in adolescence and their implications for diagnosis of hypertension

OBJECTIVES

Blood pressure (BP) is the leading global cause of mortality, and its prevalence is increasing in children and adolescents. Aortic BP is lower than brachial BP in adults. We aimed to assess the extent of this difference and its impact on the diagnosis of hypertension among adolescents.

METHODS

We used data from 3850 participants from a UK cohort of births in the early 1990s in the Southwest of England, who attended their ∼17-year follow-up and had valid measures of brachial and aortic BP at that clinic [mean (SD) age 17.8 (0.4) years, 66% female individuals]. Data are presented as mean differences [95% prediction intervals] for both sexes.

RESULTS

Aortic systolic BP (SBP) was lower than brachial SBP [male, -22.3 (-31.2, -13.3) mmHg; female, -17.8 (-25.5, -10.0) mmHg]. Differences between aortic and brachial diastolic BP (DBP) were minimal. Based on brachial BP measurements, 101 male individuals (6%) and 22 female individuals (1%) were classified as hypertensive. In contrast, only nine male individuals (<1%) and 14 female individuals (<1%) met the criteria for hypertension based on aortic BP, and the predictive value of brachial BP for aortic hypertension was poor (positive-predictive value = 13.8%). Participants with aortic hypertension had a higher left ventricular mass index than those with brachial hypertension.

CONCLUSION

Brachial BP substantially overestimates aortic BP in adolescents because of marked aortic-to-brachial pulse pressure amplification. The use of brachial BP measurement may result in an overdiagnosis of hypertension during screening in adolescence.

A Mother-Child Dyadic Approach to Evaluating Subclinical Cardiovascular Disease in Young Children: A Feasibility Study

BACKGROUND

Cardiovascular (CV) risk factors can be transmitted from mothers to their children. However, it is challenging to measure and identify subclinical CV risk in young children using traditional CV risk methods and metrics.

OBJECTIVE

The purpose of this study was to determine the feasibility of recruiting mother-child dyads and measuring arterial stiffness (pulse wave velocity, augmentation index/pressure), blood pressure (BP), BP circadian pattern, specifically nocturnal BP dipping, and CV health metrics in mothers and in children aged 1 to 5 years.

METHODS

All BP and arterial stiffness measures were obtained using the noninvasive automated oscillometric Mobil-O-Graph device. Also measured were blood cholesterol level; glucose level; body mass index (BMI); and smoking, diet, and physical activity history. Descriptive statistics were used for assessing recruitment feasibility and Pearson correlations for mother-child associations.

RESULTS

Thirty-five mother-child dyads completed the protocol. Recruitment reach was 89% and retention rate was 80%. Mothers were 34.3 ± 5.4 years old with a mean systolic BP (SBP) of 114.6 ± 9.5 mm Hg and BMI of 26.0 ± 6.5. Children were 3 ± 1.4 years old with a mean SBP of 103.3 ± 9.4 mm Hg and BMI z -scores of -0.3 ± 1.5. Arterial stiffness parameters were within normal ranges for mothers and children. Twenty-three percent of mothers did not exhibit nocturnal dipping (<10% decrease between day and nighttime SBP). Maternal SBP was positively correlated with child BMI z -scores ( r = 0.42, P = .022) as well as mother-child augmentation pressure ( r = 0.51, P = .010).

CONCLUSIONS

Our findings support using a mother-child approach and novel noninvasive approaches to assess and target CV risk in mothers and their young children.

The significance of central blood pressure for cardiovascular target organ damage in children and adolescents after kidney transplantation

BACKGROUND

Cardiovascular (CV) complications are important causes of morbidity and mortality in children after kidney transplantation (KTx). In adults, central blood pressure (cBP) is an accepted predictor of CV sequelae. We aimed to assess the prognostic value of cBP over peripheral blood pressure (pBP) for existing CV damage.

METHODS

We measured cBP and pBP in 48 pediatric KTx recipients (mean age: 13.5 ± 4.2 years). Assessment of left ventricular mass index (LVMI) and aortic pulse wave velocity (PWV) allowed detection of CV target organ damage. LVMI and PWV were used as endpoints in multivariable linear regression models, in which cBP and pBP were compared for their predictive value.

RESULTS

Using cBP z-scores, we identified a larger number of patients with uncontrolled or untreated hypertension compared to pBP (36% vs. 7%). Central systolic blood pressure (cSBP) was a significant independent predictor of LVMI, while peripheral systolic blood pressure (pSBP) was not. Comparing central (cDBP) and peripheral (pDBP) diastolic blood pressure for their predictive value on PWV revealed a greater estimate for cDBP (0.035 vs. 0.026 for pDBP) along with a slightly better model fit for cDBP.

CONCLUSIONS

Our data in a small group of patients provide first evidence that cBP measurements in pediatric KTx recipients might be helpful in identifying patients at risk for the development of CV sequelae. Investigating a larger patient number, ideally repeatedly, is needed to create further evidence supporting our findings. In light of available devices measuring cBP noninvasively, the implementation of such clinical studies post-KTx care should be feasible. A higher resolution version of the Graphical abstract is available as Supplementary information.

Superiority of 24-Hour Aortic Over 24-Hour Brachial Pressure to Associate With Carotid Arterial Damage on the Basis of Pressure Amplification Variability: the SAFAR Study

BACKGROUND

Evidence suggests marginal superiority of static aortic systolic blood pressure (aSBP) compared with brachial SBP regarding the association with organ damage and prognosis of cardiovascular disease. The noninvasive 24-hour aSBP assessment is feasible and associates better with presence of left ventricular hypertrophy compared with 24-hour brachial systolic blood pressure. We aimed at comparing the association of 24-hour aSBP and 24-hour brachial systolic blood pressure with indices of arterial damage and examining the role of 24-hour SBP amplification variability (within-subjects' SD) in this association.

METHODS

Consecutive subjects referred for cardiovascular disease risk assessment underwent 24-hour aortic and brachial ambulatory BP monitoring using a validated oscillometric device (Mobil-O-Graph). Arterial damage was assessed by carotid intima-media thickness and detection of carotid and femoral atheromatosis (plaque presence).

RESULTS

Cross-sectionally 501 individuals (aged 54±13 years, 57% men, 80% hypertensives) were examined. Multivariable analysis revealed superiority of 24-hour aSBP regarding the association with intimal-medial thickness, carotid hypertrophy and carotid-but not femoral-atheromatosis. In receiver operator characteristics analysis, 24-hour aBP displayed a higher discriminatory ability-compared to 24-hour brachial systolic blood pressure-for the detection of both carotid hypertrophy (area under the curve, 0.662 versus 0.624, P<0.05) and carotid atheromatosis (area under the curve, 0.573 versus 0.547, P<0.05). This effect was more prominent in individuals with above-median 24-hour SD of SBP amplification.

CONCLUSIONS

Our results suggest that 24-hour aSBP assessment may be of significant value in clinical practice to detect site-specific arterial damage on the basis of pressure amplification variability and should be prospectively examined in clinical trials.

Ambulatory monitoring of central arterial pressure, wave reflections, and arterial stiffness in patients at cardiovascular risk

This paper reviews current 24 h ambulatory noninvasive technologies for pulse wave analysis (PWA) providing central arterial pressure, pulse wave velocity, and augmentation index and the scientific evidence supporting their use in the clinical management of patients with arterial hypertension or at risk for cardiovascular complications.The most outstanding value of these techniques lies in the fact that they are user-friendly, mostly operator independent, and enable the evaluation of vascular function during daily-life conditions, allowing to obtain repeated measurements in different out-of-office circumstances, less artificial than those of the laboratory or doctor's office.Studies performed so far suggest that 24 h PWA may represent a potentially promising tool for evaluating vascular function, structure, and damage in daily-life conditions and promoting early screening in subjects at risk. The current evidence in favor of such an approach in the clinical practice is still limited and does not recommend its routine use. In particular, at the moment, there is a shortage of long-term prognostic studies able to support the predictive value of 24 h PWA. Finally, the accuracy of the measures is strongly dependent on the type of technology and device employed with lack of interoperability among the devices that deeply affects comparability of results among studies using different technologies. It is thus mandatory in the near future to promote proper validation studies, for instance using the ARTERY protocol, and to plan well-designed long-term longitudinal studies that may prove the accuracy and high predictive value of PWA in ambulatory conditions.

Age-specific association between invasively measured central blood pressure and left ventricular mass index

Background: The impact of age on the association between central aortic hemodynamics and left ventricular (LV) remodeling has not been well elucidated. We compared the relationship between measurements of central blood pressure (CBP) and LV mass index (LVMI) according to their ages (<50 years versus ≥50 years). Methods: A total of 305 consecutive subjects (64.4 ± 10.9 years, 60.7% males) who underwent invasive coronary angiography (ICA) for the evaluation of coronary artery disease were prospectively enrolled. Just before ICA, CBP was measured at the aortic root using a pig-tail catheter, and CBP indices, including aortic systolic blood pressure (aSBP), aortic pulse pressure (aPP), aortic fractional pulse pressure (=aPP/mean aortic pressure), and aortic pulsatility index (=aPP/diastolic aortic pressure), were recorded. All subjects underwent transthoracic echocardiography, and LVMI was measured on the same day of ICA. Results: In simple linear correlation analyses, LVMI was associated with all CBP indices in subjects aged <50 years (n = 29) (P < .05 for each), but not in those aged ≥50 years (n = 276) (P > .05 for each). In the younger age group (≤50 years), multivariable analysis showed that aSBP (β = 0.457, P= .021) and aPP (β = 0.610, P= .006) had a significant association with LVMI after adjusting for possible confounding factors. The results remained consistent even when analyzed in a 1:1 propensity score-matched cohort. In conclusion, invasively measured aPP showed the closest association with LVMI in subjects aged <50 years, but not those aged ≥50 years. Conclusion: Aortic pulsatile hemodynamic status appears to have a greater effect on LV remodeling in younger people than in older people.