Early thoracic aorta enlargement in asymptomatic individuals at risk for cardiovascular disease: determinant factors and clinical implication

Evolution and outcomes of aortic dilations in giant cell arteritis

OBJECTIVES

To identify factors associated with the progression of giant cell arteritis (GCA)-related or associated aortic dilations.

METHODS

In this retrospective study, 47 GCA patients with aortic dilation were longitudinally analyzed. Each patient underwent ≥2 imaging scans of the aorta during the follow-up. Three progression statuses of aortic dilations were distinguished: fast-progressive (FP) defined by a progression of the aortic diameter ≥5 mm/year or ≥1 cm/2 years, slow progressive (SP) by a progression of the aortic diameter >1 mm during the follow-up, and not progressive (NP) when aortic diameter remained stable.

RESULTS

Among the 47 patients with aortic dilation, the thoracic section was involved in 87 % of patients. Within a total follow-up of 89 [6-272] months, we identified 13 (28 %) patients with FP dilations, and 16 (34 %) and 18 (38 %) patients with SP and NP dilations, respectively. No differences regarding baseline characteristics, cardiovascular risk factors or treatments were observed among the 3 groups. However, FP patients more frequently showed atheromatous disease (p = 0.04), with a more frequent use of statins (p = 0.04) and antiplatelet agents (p = 0.02). Among the 27 (57 %) patients with aortitis, aortic dilation developed on an inflammatory segment in 23 (85 %). Among the FP patients who underwent aortic surgery with available histology (n = 3), all presented active vasculitis.

CONCLUSION

This study suggests that aortic inflammation, as well as atheromatous disease, might participate in the fast progression of aortic dilation in GCA.

Development of hypertension models for lung cancer screening cohorts using clinical and thoracic aorta imaging factors

This study aims to develop and validate nomogram models utilizing clinical and thoracic aorta imaging factors to assess the risk of hypertension for lung cancer screening cohorts. We included 804 patients and collected baseline clinical data, biochemical indicators, coexisting conditions, and thoracic aorta factors. Patients were randomly divided into a training set (70%) and a validation set (30%). In the training set, variance, t-test/Mann-Whitney U-test and standard least absolute shrinkage and selection operator were used to select thoracic aorta imaging features for constructing the AIScore. Multivariate logistic backward stepwise regression was utilized to analyze the influencing factors of hypertension. Five prediction models (named AIMeasure model, BasicClinical model, TotalClinical model, AIBasicClinical model, AITotalClinical model) were constructed for practical clinical use, tailored to different data scenarios. Additionally, the performance of the models was evaluated using receiver operating characteristic (ROC) curves, calibration curves and decision curve analyses (DCA). The areas under the ROC curve for the five models were 0.73, 0.77, 0.83, 0.78, 0.84 in the training set, and 0.77, 0.78, 0.81, 0.78, 0.82 in the validation set, respectively. Furthermore, the calibration curves and DCAs of both sets performed well on accuracy and clinical practicality. The nomogram models for hypertension risk prediction demonstrate good predictive capability and clinical utility. These models can serve as effective tools for assessing hypertension risk, enabling timely non-pharmacological interventions to preempt or delay the future onset of hypertension.

Prevalence and determinants of dilated ascending aorta in a Swedish population: a case-control study

Aims

Dilation of the ascending aorta (AA) is often asymptomatic until a life-threatening dissection or rupture occurs. An overall increase in the use of thoracic imaging has enabled early and sometimes incidental identification of AA dilation. Still, the prevalence and determinants of AA dilation remain to be clarified. The aim was to identify and characterize persons with AA dilation in a middle-aged Swedish population.

Methods and results

We used the Swedish CardioPulmonary BioImage Study Linköping (n = 5058, age 50-65 years) to identify cases with AA diameter ≥ 40 mm on coronary computed tomography angiography (CCTA) or chest computed tomography. Age- and gender-matched individuals with AA diameter < 40 mm served as controls. Echocardiography, blood pressure (BP) measurements (office and home), pulse wave velocity (PWV), coronary artery calcification (CAC), CCTA-detected coronary atherosclerosis, and carotid ultrasound were used to characterize these subjects. We identified 70 cases (mean AA diameter 44 mm, 77% men) and matched these to 146 controls (mean AA diameter 34 mm). Bicuspid aortic valve and aortic valve dysfunction were more common in cases than in controls (8% vs. 0% and 39% vs. 11%, respectively). Both office and home BP levels were significantly higher among cases. Also, high PWV (>10 m/s) levels were more common in cases (33% vs. 17%). Neither CAC scores nor prevalence or burden of atherosclerosis in coronary and carotid arteries differed between groups.

Conclusion

The prevalence of dilated AA was 1.4% and showed positive associations with male gender, aortic valve pathology, and diastolic BP, though not with subclinical atherosclerosis.

Computational clustering reveals differentiated coronary artery calcium progression at prevalent levels of pulse wave velocity by classifying high-risk patients

Many studies found that increased arterial stiffness is significantly associated with the presence and progression of Coronary Calcium Score (CCS). However, none so far have used machine learning algorithms to improve their value. Therefore, this study aims to evaluate the association between carotid-femoral Pulse Wave Velocity (cfPWV) and CCS score through computational clustering. We conducted a retrospective cross-sectional study using data from a cardiovascular risk screening program that included 377 participants. We used an unsupervised clustering algorithm using age, weight, height, blood pressure, heart rate, and cfPWV as input variables. Differences between cluster groups were analyzed through Chi-square and T-student tests. The association between (i) cfPWV and age groups, (ii) log (CCS) and age groups, and (iii) cfPWV and log(CCS) were addressed through linear regression analysis. Clusters were labeled post hoc based on cardiovascular risk. A "higher-risk group" had significantly higher left (0.76 vs. 0.70 mm, P < 0.001) and right (0.71 vs. 0.66 mm, P = 0.003) intima-media thickness, CCS (42 vs. 4 Agatston units, P = 0.012), and ascending (3.40 vs. 3.20 cm, P < 0.001) and descending (2.60 vs. 2.37 cm, P < 0.001) aorta diameters. Association with age appeared linear for cfPWV and exponential for log (CCS). The progression of the log (CCS) and cfPWV through age groups was steeper in the "higher-risk group" than in the "lower-risk group". cfPWV strongly correlated with CCS, and CCS progression over cfPWV differed among clusters. This finding could improve PWV as a "gate-keeper" of CCS testing and potentially enhance cardiovascular risk stratification.

Distribution, Determinants and Normal Reference Values of Aortic Arch Width: Thoracic Aortic Geometry in the Framingham Heart Study

Study Objective

Aortic arch geometry changes with age, including an increase in aortic arch width (AAW). High AAW is a predictor of incident adverse cardiovascular disease (CVD) events, but its distribution and determinants are unknown. We hypothesized that traditional CVD risk factors, in addition to age, are associated with increased AAW in community-dwelling adults.

Study Design

Framingham Offspring and Third Generation cohort participants (N=3026, 52% Men) underwent thoracic multidetector computed tomography (MDCT). A referent group (733M, 738W) free of clinical CVD, hypertension, dyslipidemia, smoking, and diabetes was used to generate sex and 10-year age-group specific upper 90th percentile (P90) cut-points for AAW. AAW was measured as the distance between the cross-sectional centroids of the ascending and descending thoracic aorta. Multivariable logistic regression models were used to identify clinical correlates of high AAW (≥referent P90) in the overall study group.

Results

Among referent participants, AAW increased with greater age-group, p for trend <0.0001 in each sex. Overall and within each age group, AAW was greater in men than women, p<0.0001 all comparisons. Across all participants, high AAW was associated with greater age (odds ratio, OR=1.34/10y; 95% confidence interval 1.20 - 1.50), body surface area (OR=1.97/SD; 1.62 - 2.40), diastolic blood pressure (OR=1.59/10mmHg; 1.40 - 1.81), pack-years smoked (OR=1.07; 1.02 - 1.13), and prevalent CVD (OR=1.64; 1.08 - 2.49).

Conclusion

AAW increases with greater age, body size, diastolic blood pressure and burden of smoking. High AAW (≥referent P90) is also associated with prevalent (clinically apparent) CVD. AAW is often seen on and easily measured from tomographic thoracic images and has prognostic value.

Potential influencing factors of aortic diameter at specific segments in population with cardiovascular risk

Background

Aortic diameter is a critical parameter for the diagnosis of aortic dilated diseases. Aortic dilation has some common risk factors with cardiovascular diseases. This study aimed to investigate potential influence of traditional cardiovascular risk factors and the measures of subclinical atherosclerosis on aortic diameter of specific segments among adults.

Methods

Four hundred and eight patients with cardiovascular risk factors were prospectively recruited in the observational study. Comprehensive transthoracic M-mode, 2-dimensional Doppler echocardiographic studies were performed using commercial and clinical diagnostic ultrasonography techniques. The aortic dimensions were assessed at different levels: (1) the annulus, (2) the mid-point of the sinuses of Valsalva, (3) the sinotubular junction, (4) the ascending aorta at the level of its largest diameter, (5) the transverse arch (including proximal arch, mid arch, distal arch), (6) the descending aorta posterior to the left atrium, and (7) the abdominal aorta just distal to the origin of the renal arteries. Multivariable linear regression analysis was used for evaluating aortic diameter-related risk factors, including common cardiovascular risk factors, co-morbidities, subclinical atherosclerosis, lipid profile, and hematological parameters.

Results

Significant univariate relations were found between aortic diameter of different levels and most traditional cardiovascular risk factors. Carotid intima-media thickness was significantly correlated with diameter of descending and abdominal aorta. Multivariate linear regression showed potential effects of age, sex, body surface area and some other cardiovascular risk factors on aortic diameter enlargement. Among them, high-density lipoprotein cholesterol had a significantly positive effect on the diameter of ascending and abdominal aorta. Diastolic blood pressure was observed for the positive associations with diameters of five thoracic aortic segments, while systolic blood pressure was only independently related to mid arch diameter.

Conclusion

Aortic segmental diameters were associated with diastolic blood pressure, high-density lipoprotein cholesterol, atherosclerosis diseases and other traditional cardiovascular risk factors, and some determinants still need to be clarified for a better understanding of aortic dilation diseases.

Aortic Unfolding Measurement Using Non-Contrast Cardiac CT: Normal Range of Low-Risk Subjects

Purpose

Materials and Methods

Results

Conclusion

Aortic enlargement and coronary artery calcification in a general population cohort

AIMS

The role of atherosclerosis in the pathogenesis of aortic enlargement is uncertain. We aimed to evaluate the relationship between the diameters of the ascending, descending and abdominal aorta, and coronary artery calcification.

METHODS AND RESULTS

Individuals in the Copenhagen General Population Study underwent thoracic and abdominal computed tomography. Maximal aortic diameters were measured in each aortic segment and coronary artery calcium scores (CACS) were calculated. Participants were stratified into five predefined groups according to CACSs and compared to aortic dimensions. The relation between aortic diameter and CACS was adjusted for risk factors for aortic dilatation in a multivariable model. A total of 2678 eligible individuals were included. In all segments of the aorta, aortic diameter was associated to CACSs, with mean increases in aortic diameters ranging from 0.7 to 3.5 mm in individuals with calcified coronary arteries compared to non-calcified subjects (P-value < 0.001). After correction for risk factors, individuals with CACS above 400 had larger ascending, descending and abdominal aortic diameter than the non-calcified reference group (P-value < 0.01).

CONCLUSION

Enlarged thoracic and abdominal aortic vascular segments are associated with co-existing coronary artery calcification in the general population.

Out of proportion proximal aortic remodeling: A subclinical marker of early vascular ageing? A systematic review

INTRODUCTION

Proximal aorta stiffens and dilates with aging. Aortic stiffening is a well known process, carrying prognostic implications. On the contrary, few data are available about proximal aorta dilatation. It is not known if "out of proportion" aortic remodeling, i.e. in excess for age, sex and body size, could be a marker of early vascular ageing; there is controversy on how it would be accelerated by classical risk factors or would associate with validated markers of cardiovascular organ damage.

AIM

We conducted a systematic review in order to evaluate the determinants of proximal aortic dimensions, focusing on the association with arterial hypertension, cardiovascular risk factors and markers of organ damage.

DETERMINANTS OF PROXIMAL AORTA REMODELING

Age, gender and body size explain 40-50% of the variability of aortic dimensions; genetic predisposition accounts for nearly 20%. Among cardiovascular risk factors obesity and hypertension seem to be associated with faster outward aortic remodeling. Arterial hypertension would account for a 0.60-0.78 mm greater diameter at the ascending aorta. Moreover, in hypertension, left ventricular mass showed a strict association with aortic diameter in nearly all studies. Other classical risk factors for atherogenesis such as dyslipidemia and smoking showed a weak influence on proximal aortic dimensions. No study reported a greater aortic remodeling in diabetics.

CONCLUSIONS

"Out of proportion" proximal aortic remodeling, could represent a subclinical marker of early vascular ageing, describing the cumulative influence of genetic predisposition, arterial hypertension and obesity.

Hemodynamic Correlates of Abnormal Aortic Root Dimension in an Adult Population: The Strong Heart Study

Background

We evaluated the relationship of aortic root dimension (ARD) with flow output and both peripheral and central blood pressure, using multivariable equations predicting ideal sex‐specific ARD at a given age and body height.

Methods and Results

We measured echocardiographic diastolic ARD at the sinuses of Valsalva in 3160 adults (aged 42±16 years, 61% women) from the fourth examination of the Strong Heart Study who were free of prevalent coronary heart disease, and we compared measured data with the theoretical predicted value to calculate a z score. Central blood pressure was estimated by applanation tonometry of the radial artery in 2319 participants. ARD z scores were divided into tertiles representing small, normal, and large ARD. Participants with large ARD exhibited greater prevalence of central obesity and higher levels of inflammatory markers and lipids (0.05<P<0.0001). Stroke volume, heart rate, and both cuff and central diastolic blood pressure were progressively greater from small to large ARD (all P<0.0001). Pulse pressure was higher in small ARD (P<0.0001). In multivariable analysis, ARD z score was related positively to stroke volume, either cuff or central diastolic blood pressure, and negatively to pulse pressure. Large ARD was also independently correlated to higher waist circumference and percentages of neutrophils and plasminogen activator inhibitor‐1 (all P<0.01).

Conclusions

Aortic root dilatation is associated with high diastolic blood pressure, high stroke volume, central fat distribution, and inflammatory status. In contrast, at a given diastolic blood pressure and stroke volume, aortic root dilatation is associated with lower pulse pressure and systolic blood pressure.

Determinants and normal values of ascending aortic diameter by age, gender, and race/ethnicity in the Multi-Ethnic Study of Atherosclerosis (MESA)

PURPOSE

To determine the normal size and wall thickness of the ascending thoracic aorta (AA) and its relationship with cardiovascular risk factors in a large population-based study.

MATERIALS AND METHODS

The mean AA luminal diameter was measured in 3573 Multi-Ethnic Study of Atherosclerosis (MESA) participants (age: 45-84 years), using gradient echo phase contrast cine MRI. Multiple linear regression models were used to evaluate the associations between risk factors and AA diameter. The median and upper normal limit (95th percentile) was defined in a "healthy" subgroup as well as AA wall thickness.

RESULTS

The upper limits of body surface area indexed AA luminal diameter for age categories of 45-54, 55-64, 65-74, and 75-84 years are 21, 22, 22, and 28 mm/m(2) in women and 20, 21, 22, 23 mm/m(2) in men, respectively. The mean AA wall thickness was 2.8 mm. Age, gender, and body surface area were major determinants of AA luminal diameter (∼+1 mm/10 years; ∼+1.9 mm in men than women; ∼+1 mm/ 0.23 m(2) ; P < 0.001). The AA diameter in hypertensive subjects was +0.9 mm larger than in normotensives (P < 0.001).

CONCLUSION

AA diameter increases gradually with aging for both genders among all race/ethnicities. The normal value of AA diameter is provided.

Effects of aging on thoracic aorta size and shape: a non-contrast CT study

Measures of atherosclerosis burden like coronary artery calcification are performed using non-contrast heart CT. However, additional information can be derived from these studies, looking beyond the coronary arteries without exposing the patients to further radiation. We present a semi-automated method to assess ascending, arch and descending aorta geometry from non-contrast CT datasets in 250 normotensive patients. We investigated the effect of aging on thoracic aorta morphometry. The algorithm identifies the aortic centerline coordinates following a toroidal path for the curvilinear portion and axial planes for descending aorta. Then it reconstructs oblique planes orthogonal to the centerline direction and a circle fitting process estimates the vessel cross-section. Finally, global thoracic aorta dimensions (diameter, volume and length) and shape (vessel curvature and tortuosity, aortic arch width and height) are calculated. From a multivariate analysis, adjusted for gender and body-size area, aortic volume and arch width were the descriptors that better represented the aortic size and shape alterations with aging. The thoracic aorta suffers an expanding and unfolding process with aging that deserves further attention to prevent aortic aneurisms.

Three-dimensional evaluation of thoracic aorta enlargement and unfolding in hypertensive men using non-contrast computed tomography

Aging produces a simultaneous thoracic aorta (TA) enlargement and unfolding. We sought to analyze the impact of hypertension on these geometric changes. Non-contrast computed tomography images were obtained from coronary artery calcium scans, including the entire aortic arch, in 200 normotensive and 200 hypertensive asymptomatic men. An automated algorithm reconstructed the vessel in three-dimensions, estimating orthogonal aortic sections along the whole TA pathway, and calculated several geometric descriptors to assess TA morphology. Hypertensive patients were older with respect to normotensive (P<0.001). Diameter and volume of TA ascending, arch and descending segments were higher in hypertensive patients with respect to normotensive (P<0.001) and differences persisted after adjustment for age. Hypertension produced an accelerated unfolding effect on TA shape. We found increments in aortic arch width (P<0.001), radius of curvature (P<0.001) and area under the arch curve (P<0.01) with a concomitant tortuosity decrease (P<0.05) and no significant change in aortic arch height. Overall, hypertension produced an equivalent effect of 2-7-years of aging. In multivariate analysis adjusted for age and hypertension treatment, diastolic pressure was more associated to TA size and shape changes than systolic pressure. These data suggest that hypertension accelerates TA enlargement and unfolding deformation with respect to the aging effect.

Aging impact on thoracic aorta 3D morphometry in intermediate-risk subjects: looking beyond coronary arteries with non-contrast cardiac CT

An increasing number of intermediate risk asymptomatic subjects benefit from measures of atherosclerosis burden like coronary artery calcification studies with non-contrast heart computed tomography (CT). However, additional information can be derived from these studies, looking beyond the coronary arteries and without exposing the patients to further radiation. We report a semi-automatic method that objectively assesses ascending, arch and descending aorta dimension and shape from non-contrast CT datasets to investigate the effect of aging on thoracic aorta geometry. First, the segmentation process identifies the vessel centerline coordinates following a toroidal path for the curvilinear portion and axial planes for descending aorta. Then, reconstructing oblique planes orthogonal to the centerline direction, it iteratively fits circles inside the vessel cross-section. Finally, regional thoracic aorta dimensions (diameter, volume and length) and shape (vessel curvature and tortuosity) are calculated. A population of 200 normotensive men was recruited. Length, mean diameter and volume differed by 1.2 cm, 0.13 cm and 21 cm(3) per decade of life, respectively. Aortic shape uncoiled with aging, reducing its tortuosity and increasing its radius of curvature. The arch was the most affected segment. In conclusion, non-contrast cardiac CT imaging can be successfully employed to assess thoracic aorta 3D morphometry.