Abstract-Arterial stiffness predicts cardiovascular events beyond traditional risk factors. However, the relationship with aging of novel noninvasive measures of aortic function by MRI and their interrelationship with established markers of vascular stiffness remain unclear and currently limit their potential impact. Our aim was to compare age-related changes of central measures of aortic function with carotid distensibility, global carotid-femoral pulse wave velocity, and wave reflections. We determined aortic strain, distensibility, and aortic arch pulse wave velocity by MRI, carotid distensibility by ultrasound, and carotid-femoral pulse wave velocity by tonometry in 111 asymptomatic subjects (54 men, age range: 20 to 84 years). Central pressures were used to calculate aortic distensibility. Peripheral and central pulse pressure, augmentation index, and carotid-femoral pulse wave velocity increased with age, but aortic strain and aortic arch PWV were most closely and specifically related to aging. Ascending aortic (AA) strain and distensibility decreased, respectively, by 5.3Ϯ0.5% (R 2 ϭ0.54, PϽ0.0001) and 13.6Ϯ1 kPa Ϫ1 ϫ10 Ϫ3 (R 2 ϭ0.62, PϽ0.0001), and aortic arch pulse wave velocity increased by 1.6Ϯ0.13 m/sec (R 2 ϭ0.60, PϽ0.0001) for each decade of age after adjustment for gender, body size, and heart rate. We demonstrate in this study a dramatic decrease in AA distensibility before the fifth decade of life in individuals with diverse prevalence of risk factors free of overt cardiovascular disease. In particular, compared with other measures of aortic function, the best markers of subclinical large artery stiffening, were AA distensibility in younger and aortic arch pulse wave velocity in older individuals. (Hypertension. 2010;55:319-326.) Key Words: MRI Ⅲ aorta Ⅲ aging Ⅲ elasticity Ⅲ pulse wave velocity A ge-related vascular changes in individuals without overt cardiovascular disease and normal blood pressure remain currently undetected. However, the ability to identify individuals having early deterioration of vascular and cardiac function, as well as progressive subclinical arterial disease, would allow to define a target population for preventive therapy in the hope of reducing vascular and cardiac remodeling and dysfunction, as well as preventing lethal or incapacitating events. Arterial stiffness is a main determinant of age-related systolic and pulse pressure increase, a major predictor of stroke and myocardial infarction, and has been associated with heart failure. 1-3 The aorta accounts for most of global arterial stiffening and is central to the onset of atherosclerosis with its subsequent complications. The value of carotid-femoral pulse wave velocity (cfPWV) as a marker of arterial stiffness and a predictor of fatal and nonfatal cardiovascular events over traditional risk factors has been established both in patients and the general population. 4 Similarly, the carotid augmentation index (AIx), a marker of waveform reflection and central pulse pressure (PP), have independent predictive value f...

BACKGROUND The predictive value of ascending aortic distensibility (AAD) for mortality and hard cardiovascular disease (CVD) events is not fully established. OBJECTIVES We sought to assess the utility of AAD to predict mortality and incident CVD events beyond conventional risk factors in the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS AAD was measured with magnetic resonance imaging at baseline in 3,675 MESA participants free of overt CVD. Cox proportional-hazards regression was used to evaluate risk of death, heart failure (HF), and incident CVD in relation to AAD, CVD risk factors, indices of subclinical atherosclerosis, and Framingham risk score. RESULTS There were 246 deaths and 171 hard CVD (myocardial infarction, resuscitated cardiac arrest, stroke and cardiovascular [CV] death) and 88 HF events over a median 8.5-year follow-up. Decreased AAD was associated with increased all-cause mortality with a hazard ratio (HR) for the first verus fifth quintile of AAD of 2.7 (p = 0.008) independent of age, sex, ethnicity, other CVD risk factors, and indices of subclinical atherosclerosis. Overall, subjects with lowest AAD had an independent 2-fold risk of hard CVD events. Decreased AAD was associated with CV events in low-to-intermediate CVD risk individuals with an HR for the first quintile of AAD of 5.3 (p = 0.03) as well as with incident HF but not after full adjustment. CONCLUSIONS Decreased proximal aorta distensibility significantly predicts all-cause mortality and hard CV events among individuals without overt CVD. AAD may help refine risk stratification, especially among asymptomatic, low-to-intermediate risk individuals.

Purpose: To investigate the efficiency of a new method (TT-Upslope) for transit time (Dt) estimation from cardiovascular MR (CMR) velocity curves. Materials and Methods:Fifty healthy volunteers (40 6 15 years) underwent applanation tonometry to estimate carotid-femoral pulse wave velocity (cf-PWV) and carotid pressure measurements, and CMR to estimate aortic arch-PWV and ascending aorta distensibility (AAD). The Dt was calculated with TT-Upslope by minimizing the area delimited by two sigmoid curves fitted to the systolic upslope of the ascending (AAC) and descending (DAC) aorta velocity curves, and compared with previously described methods: TT-Point using the half maximum of AAC and DAC, TT-Foot using AAC and DAC feet, and TTWave by minimizing the area between AAC and DAC curves using cross correlation. Conclusion: Arch-PWV estimated with CMR using the TT-Upslope method was found to be reproducible and accurate, providing strong correlations with age and aortic stiffness indices.

Objectives To define age-related geometric changes of the aortic arch and determine their relationship to central aortic stiffness and left ventricular remodeling. Background The proximal aorta has been shown to thicken, enlarge in diameter and lengthen with aging in humans. However, no systematic study has described age-related longitudinal and transversal remodeling of the aortic arch and their relationship with left ventricular mass and remodeling. Methods We studied 100 subjects (55 women, 45 men, average age: 46±16 years) free of overt cardiovascular disease using magnetic resonance imaging to determine aortic arch geometry (length, diameters, height, width and curvature), aortic arch function (local aortic distensibility and arch pulse wave velocity PWV) and left ventricular volumes and mass. Radial tonometry was used to calculate central blood pressure. Results Aortic diameters and arch length increased significantly with age. The ascending aorta increased most with age leading to aortic arch widening and decreased curvature. These geometric changes of the aortic arch were significantly related to decreased ascending aortic distensibility, increased aortic arch PWV (p<0.001) and to increased central blood pressures (p<0.001). Increased ascending aortic diameter, lengthening and decreased curvature of the aortic arch (unfolding) were all significantly associated with increased LV mass and concentric remodeling independently of age, gender, body size and central blood pressure (p<0.01). Conclusions Age-related unfolding of the aortic arch is related to increased proximal aortic stiffness in individuals without cardiovascular disease and associated with increased LV mass and mass-to-volume ratio independent of age, body size, central pressure and cardiovascular risk factors.

Background:Patients with Cushing's syndrome have left ventricular (LV) hypertrophy and dysfunction on echocardiography, but echo-based measurements may have limited accuracy in obese patients. No data are available on right ventricular (RV) and left atrial (LA) size and function in these patients.Objectives:The objective of the study was to evaluate LV, RV, and LA structure and function in patients with Cushing's syndrome by means of cardiac magnetic resonance, currently the reference modality in assessment of cardiac geometry and function.Methods:Eighteen patients with active Cushing's syndrome and 18 volunteers matched for age, sex, and body mass index were studied by cardiac magnetic resonance. The imaging was repeated in the patients 6 months (range 2–12 mo) after the treatment of hypercortisolism.Results:Compared with controls, patients with Cushing's syndrome had lower LV, RV, and LA ejection fractions (P < .001 for all) and increased end-diastolic LV segmental thickness (P < .001). Treatment of hypercortisolism was associated with an improvement in ventricular and atrial systolic performance, as reflected by a 15% increase in the LV ejection fraction (P = .029), a 45% increase in the LA ejection fraction (P < .001), and an 11% increase in the RV ejection fraction (P = NS). After treatment, the LV mass index and end-diastolic LV mass to volume ratio decreased by 17% (P < .001) and 10% (P = .002), respectively. None of the patients had late gadolinium myocardial enhancement.Conclusion:Cushing's syndrome is associated with subclinical biventricular and LA systolic dysfunctions that are reversible after treatment. Despite skeletal muscle atrophy, Cushing's syndrome patients have an increased LV mass, reversible upon correction of hypercortisolism.

Purpose: To assess if segmentation of the aorta can be accurately achieved using the modulus image of phase contrast (PC) magnetic resonance (MR) acquisitions.Materials and Methods: PC image sequences containing both the ascending and descending aorta of 52 subjects were acquired using three different MR scanners. An automated segmentation technique, based on a 2Dþt deformable surface that takes into account the features of PC aortic images, such as flow-related effects, was developed. The study was designed to: 1) assess the variability of our approach and its robustness to the type of MR scanner, and 2) determine its sensitivity to aortic dilation and its accuracy against an expert manual tracing.Results: Interobserver variability in the lumen area was 0.59 6 0.92% for the automated approach versus 10.09 6 8.29% for manual segmentation. The mean Dice overlap measure was 0.945 6 0.014. The method was robust to the aortic size and highly correlated (r ¼ 0.99) with the manual tracing in terms of aortic area and diameter.Conclusion: A fast and robust automated segmentation of the aortic lumen was developed and successfully tested on images provided by various MR scanners and acquired on healthy volunteers as well as on patients with a dilated aorta.

BackgroundEarly detection of diastolic dysfunction is crucial for patients with incipient heart failure. Although this evaluation could be performed from phase-contrast (PC) cardiovascular magnetic resonance (CMR) data, its usefulness in clinical routine is not yet established, mainly because the interpretation of such data remains mostly based on manual post-processing. Accordingly, our goal was to develop a robust process to automatically estimate velocity and flow rate-related diastolic parameters from PC-CMR data and to test the consistency of these parameters against echocardiography as well as their ability to characterize left ventricular (LV) diastolic dysfunction.ResultsWe studied 35 controls and 18 patients with severe aortic valve stenosis and preserved LV ejection fraction who had PC-CMR and Doppler echocardiography exams on the same day. PC-CMR mitral flow and myocardial velocity data were analyzed using custom software for semi-automated extraction of diastolic parameters. Inter-operator reproducibility of flow pattern segmentation and functional parameters was assessed on a sub-group of 30 subjects. The mean percentage of overlap between the transmitral flow segmentations performed by two independent operators was 99.7 ± 1.6%, resulting in a small variability (<1.96 ± 2.95%) in functional parameter measurement. For maximal myocardial longitudinal velocities, the inter-operator variability was 4.25 ± 5.89%. The MR diastolic parameters varied significantly in patients as opposed to controls (p < 0.0002). Both velocity and flow rate diastolic parameters were consistent with echocardiographic values (r > 0.71) and receiver operating characteristic (ROC) analysis revealed their ability to separate patients from controls, with sensitivity > 0.80, specificity > 0.80 and accuracy > 0.85. Slight superiority in terms of correlation with echocardiography (r = 0.81) and accuracy to detect LV abnormalities (sensitivity > 0.83, specificity > 0.91 and accuracy > 0.89) was found for the PC-CMR flow-rate related parameters.ConclusionsA fast and reproducible technique for flow and myocardial PC-CMR data analysis was successfully used on controls and patients to extract consistent velocity-related diastolic parameters, as well as flow rate-related parameters. This technique provides a valuable addition to established CMR tools in the evaluation and the management of patients with diastolic dysfunction.

Remodeling reversal observed in controlled hypertensives seems to include short-term functional and long-term structural changes.