Twenty-Four–Hour Central (Aortic) Systolic Blood Pressure: Reference Values and Dipping Patterns in Untreated Individuals

Abstract

Central (aortic) systolic blood pressure (cSBP) is the pressure seen by the heart, the brain, and the kidneys. If properly measured, cSBP is closer associated with hypertension-mediated organ damage and prognosis, as compared with brachial SBP (bSBP). We investigated 24-hour profiles of bSBP and cSBP, measured simultaneously using Mobilograph devices, in 2423 untreated adults (1275 women; age, 18–94 years), free from overt cardiovascular disease, aiming to develop reference values and to analyze daytime-nighttime variability. Central SBP was assessed, using brachial waveforms, calibrated with mean arterial pressure (MAP)/diastolic BP (cSBP MAP/DBPcal ), or bSBP/diastolic blood pressure (cSBP SBP/DBPcal ), and a validated transfer function, resulting in 144 509 valid brachial and 130 804 valid central measurements. Averaged 24-hour, daytime, and nighttime brachial BP across all individuals was 124/79, 126/81, and 116/72 mm Hg, respectively. Averaged 24-hour, daytime, and nighttime values for cSBP MAP/DBPcal were 128, 128, and 125 mm Hg and 115, 117, and 107 mm Hg for cSBP SBP/DBPcal , respectively. We pragmatically propose as upper normal limit for 24-hour cSBP MAP/DBPcal 135 mm Hg and for 24-hour cSBP SBP/DBPcal 120 mm Hg. bSBP dipping (nighttime-daytime/daytime SBP) was −10.6 % in young participants and decreased with increasing age. Central SBP SBP/DBPcal dipping was less pronounced (−8.7% in young participants). In contrast, cSBP MAP/DBPcal dipping was completely absent in the youngest age group and less pronounced in all other participants. These data may serve for comparison in various diseases and have potential implications for refining hypertension diagnosis and management. The different dipping behavior of bSBP versus cSBP requires further investigation.

Central hypertension is a non‐negligible cardiovascular risk factor

“… 29 With advanced technology, simultaneous ambulatory monitoring of brachial and central hemodynamics is now available for clinical use. 23 Given large amount of evidence showed that the 24‐h ambulatory BP was a better cardiovascular risk predictor than the office BP, irrespective of at brachial 35 or central 36 , 37 , 38 sites, it is warranted to explore if the ambulatory central BP outperforms ambulatory brachial BP in risk stratification and hypertension management. Ultimately, direct interventional evidence is needed to demonstrate whether targeting central hypertension with an optimized antihypertensive drug treatment would be beneficial beyond the control of brachial hypertension.…”

“…29 With advanced technology, simultaneous ambulatory monitoring of brachial and central hemodynamics is now available for clinical use. 23 Given large amount of evidence showed that the 24-h ambulatory BP was a better cardiovascular risk predictor than the office BP, irrespective of at brachial 35 or central [36][37][38]…”

“…The 90th percentiles of central systolic BP for the optimal, normal, and high‐normal categories were 110, 125, and 135 mmHg, respectively, for women and 111, 122, and 132 mmHg, respectively, for men in a total of 18,183 “normal” subjects 20 . Based on the mean values of the entire group and the 90th percentiles of the truly normotensive group among the 2423 untreated adults without overt cardiovascular disease, the International Academic 24‐H Ambulatory Aortic Blood Pressure Consortium (i24abc.org) proposed 135 mmHg as the upper normal limit for the 24‐h central systolic BP calibrated with brachial mean and diastolic arterial pressures, and 120 mmHg for that calibrated with brachial systolic and diastolic pressures 23 . Of note, the proposed thresholds relied heavily on the characteristics of the so‐called healthy population and ignored the associations of cardiovascular endpoints with central BPs.…”

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

“…We performed specific analyses to detect potential sex effect on our results; however, none of these revealed a role of sex in the association of BP indices with arterial damage. Given the well-described central hemodynamic differences between men and women 35 and the very recently described differences in 24-hour aortic hemodynamics, 36 we suggest that further studies in larger populations should also examine a potential sex effect on the association of 24-hour aortic hemodynamics with vascular function, which cannot be negated by the present finding due to sample size limitations. Moreover, since this is a cross-sectional study, no conclusions can be drawn on the clinical implications and prognostic value of this methodology and no extraction of causal relationships can be made.…”

Clinical implications of central blood pressure measured by radial tonometry and automated office blood pressure measured using automatic devices in cardiovascular diseases

“…In the 24-h ambulatory blood pressure (ABP) study, 24-h central ABP, measured with regular brachial cuffs and dedicated software, tends to be superior to 24-h brachial ASBP in predicting organ damage related to the heart, which is LV hypertrophy ( 35 ). Additionally, these researchers suggest upper normal limits for 24-h central SBP of 135 mmHg and for 24-h central SBP of 120 mmHg as measured by invasive and non-invasive gold standard methods ( 36 ).…”