Topic
Aortic Augmentation Index
About: Aortic Augmentation Index is a research topic. Over the lifetime, 189 publications have been published within this topic receiving 18442 citations.
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TL;DR: Aortic stiffness expressed as aortic PWV is a strong predictor of future CV events and all-cause mortality and the predictive ability of arterial stiffness is higher in subjects with a higher baseline CV risk.
3,403 citations
TL;DR: The CAFE study as mentioned in this paper examined the impact of two different BP lowering-regimens (atenolol±thiazide-based versus amlodipine±perindopril-based) on derived central aortic pressures and hemodynamics.
Abstract: Background— Different blood pressure (BP)–lowering drugs could have different effects on central aortic pressures and thus cardiovascular outcome despite similar effects on brachial BP. The Conduit Artery Function Evaluation (CAFE) study, a substudy of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), examined the impact of 2 different BP lowering-regimens (atenolol±thiazide-based versus amlodipine±perindopril-based therapy) on derived central aortic pressures and hemodynamics. Methods and Results— The CAFE study recruited 2199 patients in 5 ASCOT centers. Radial artery applanation tonometry and pulse wave analysis were used to derive central aortic pressures and hemodynamic indexes on repeated visits for up to 4 years. Most patients received combination therapy throughout the study. Despite similar brachial systolic BPs between treatment groups (Δ0.7 mm Hg; 95% CI, −0.4 to 1.7; P=0.2), there were substantial reductions in central aortic pressures with the amlodipine regimen (central aortic systolic ...
2,062 citations
TL;DR: Data suggest that AIx might be a more sensitive marker of arterial stiffening and risk in younger individuals but aortic PWV is likely to be a better measure in older individuals.
1,315 citations
TL;DR: Central aortic pressures can be accurately estimated from radial tonometry with the use of a generalized TF, and the reconstructed waveform can provide arterial compliance estimates but may underestimate the augmentation index because the latter requires greater fidelity reproduction of the wave contour.
Abstract: Background Central aortic pressures and waveform convey important information about cardiovascular status, but direct measurements are invasive. Peripheral pressures can be measured noninvasively, and although they often differ substantially from central pressures, they may be mathematically transformed to approximate the latter. We tested this approach, examining intersubject and intrasubject variability and the validity of using a single averaged transformation, which would enhance its applicability. Methods and Results Invasive central aortic pressure by micromanometer and radial pressure by automated tonometry were measured in 20 patients at steady state and during hemodynamic transients (Valsalva maneuver, abdominal compression, nitroglycerin, or vena caval obstruction). For each patient, transfer functions (TFs) between aortic and radial pressures were calculated by parametric model and results averaged to yield individual TFs. A generalized TF was the average of individual functions. TFs varied among patients, with coefficients of variation for peak amplitude and frequency at peak amplitude of 24.9% and 16.9%, respectively. Intrapatient TF variance with altered loading (>20% variation in peak amplitude) was observed in 28.5% of patients. Despite this, the generalized TF estimated central arterial pressures to ≤0.2±3.8 mm Hg error, arterial compliance to 6±7% accuracy, and augmentation index to within −7% points (30±45% accuracy). Individual TFs were only marginally superior to the generalized TF for reconstructing central pressures. Conclusions Central aortic pressures can be accurately estimated from radial tonometry with the use of a generalized TF. The reconstructed waveform can provide arterial compliance estimates but may underestimate the augmentation index because the latter requires greater fidelity reproduction of the wave contour.
1,211 citations
TL;DR: Aortic pressure pulse waves, generated from the radial pulse, showed agreement with the measured aortic pulse waves with respect to systolic, diastolic, pulse, and mean pressures, with mean differences <1 mm Hg.
Abstract: Pressure wave reflection in the upper limb causes amplification of the arterial pulse so that radial systolic and pulse pressures are greater than in the ascending aorta. Wave transmission properti...
1,164 citations