Aortic Circumferential Strain Research Articles

Quantitative Analysis of Radiation Therapy-Induced Cardiac and Aortic Sequelae in Patients With Lung Cancer via Magnetic Resonance Imaging: A Pilot Study

PurposeTo quantify early radiotherapy (RT)-induced cardiac and aortic changes in patients with lung cancer using cardiac MRI. Methods and MaterialsNine patients with lung cancer treated with RT completed MR scans at baseline (before RT), 3 months, and 6 months following RT. Cine, T1/T2, late gadolinium enhancement (LGE), and 4D-flow MRIs were acquired to assess biological and mechanical cardiovascular changes globally (i.e., over the entire left ventricle (LV) or aorta) and regionally (according to an American Heart Association model). ResultsRegional metrics demonstrated multiple significant changes and dose-dependent responses. Notably, LGE showed changes at 3 and 6 months over septal and high-dose regions (P<0.0458). Longitudinal strain changes were notable at septal and high-dose regions at 3 months and septal regions at 6 months (P<0.0469). Elevated T1/T2 signals (P<0.0391) and changes in radial/circumferential strain at the septum (P<0.0391) were observed at 3 months. Both T1/T2 signal and LGE were correlated with dose at 6 months (T1 signal also at 3 months), with significantly greater changes in regions receiving >50 Gy (P<0.0331). LV dose was not correlated with LV strain changes (P>0.1), but ascending aortic dose was correlated with strain changes at segments 1 and 2 of the LV (P<0.0362). Global metrics identified only two significant responses: increase in LGE volume at 6 months and a reduction in ascending aortic circumferential strain at 3 months (P<0.0356). ConclusionEarly MR-based changes following RT occurred primarily in high-dose regions and the LV septal wall. While several early signals resolved by 6 months, LGE and longitudinal strain changes persisted for at least 6 months. Dose-dependent responses/correlations were observed for T1/T2/LGE changes at 6 months, with the greatest effect in regions exposed to >50 Gy. Further investigations with larger cohorts and longer follow-up are warranted to confirm regional dose dependence and the association between aortic dose and LV strain observed in this pilot study.

Spectrum of ascending aortic aneurysms at a peri-urban tertiary hospital: an echocardiography-based study.

Thoracic ascending aortic (TAA) aneurysms are an important cause of disability and death and require early detection for effective management. Currently, there is a paucity of data from Africa pertaining to TAA aneurysms. This study describes the spectrum of TAA aneurysms at a peri-urban tertiary hospital. A descriptive retrospective study based on clinical and echocardiographic imaging data of patients with TAA aneurysms from October 2017-October 2022. Advanced strain imaging was performed to measure left ventricular (LV) basal, apical, and global longitudinal strain as well as circumferential strain (CS) of the ascending aorta as a proxy measurement of aortic compliance. The study comprised 139 cases of TAA aneurysms (52.5% females) with a mean age of 50 ± 14.8 years with 45 age and gender matched controls. Most cases (95%) were of African ethnicity. The main etiologies were hypertension (41.7%), HIV (36.6%), connective tissue disease (10.7%), congenital (2.2%) and mixed pathologies (8.6%). Two-thirds of patients (69.7%) presented in heart failure, 10% presented with aortic dissection. Thirty percent of the patients were classified as New York Heart Association (NYHA) class I, 59.7% NYHA II, 8.6% NYHA III and two patients NYHA class IV. Echocardiography revealed enlarged aortic dimensions compared to controls (P < 0.001). TAA aneurysms were complicated by severe aortic regurgitation (AR) in half (50.3%) of patients, moderate AR in 25.8%, and mild AR in 14.3%. The mean LV ejection fraction (46.9 ± 12.7%) was reduced compared to controls (P < 0.001). Aortic CS was reduced compared to controls [4.4 (3.2-6.2) % vs. 9.0 (7.1-13.4) %, P < 0.001]. Aortic stiffness was higher in the aortic aneurysm group compared to controls (15.39 ± 20.65 vs. 5.04 ± 2.09, P = 0.001). LV longitudinal strain (-13.9 ± 3.9% vs. 18.1 ± 6.7%), basal CS (-13.9 ± 5.6% vs. -17.9 ± 5.8%) and apical CS (-8.7 ± 8.5% vs. -30.6 ± 3.8%) were reduced compared to controls (P < 0.001). Most patients were on diuretic and anti-remodeling therapy. Surgery was performed in 29.4% and overall mortality was 7.9%. Mortality for acute aortic dissection was 40%. TAA aneurysms associated with hypertension and HIV are common in this predominantly African female population and are associated with considerable morbidity and mortality. Two-dimensional echocardiography and advanced strain imaging are potential tools for detecting and risk stratifying TAA aneurysms.

Spectrum of ascending aortic aneurysms at a peri urban tertiary hospital: an echocardiography-based study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Thoracic ascending aortic (TAA) aneurysms are an important cause of clinical disability that require early detection by imaging methods for rapid and effective management. There is a paucity of data from Africa pertaining to TAA aneurysms. Purpose To describe the spectrum of TAA aneurysms at a Tertiary hospital in Africa. Methods A descriptive retrospective study was conducted based on clinical and echocardiographic imaging data of patients with clinical diagnosis of TAA, from October 2017-October 2022. Advanced strain imaging using speckle tracking echocardiography was performed to determine the circumferential strain (CS) of ascending aorta as a surrogate of compliance. Left ventricular global longitudinal, and basal and apical circumferential strain were also determined. Results The study comprised 139 cases of TAA aneurysms (52.5% females) with a mean age of 50±14.8 years, and 45 age and gender matched normal controls. Majority were of African ethnicity (95%). Main etiologies were hypertension (41.7%), human immunodeficiency virus (HIV) (36.6%), connective tissue disease (10.7%), congenital (2.2%) and mixed pathologies in 8.6% of patients. Two thirds of patients (69.7%) presented in heart failure and 10% of patients presented with aortic dissection. Thirty percent of the patients were in New York Heart Association (NYHA) class I, 59.7% were in NYHA II, 8.6 % in NYHA III and 1.4% of patients in NYHA class IV. Echocardiography revealed enlarged aortic dimensions compared to controls (P=0.00000). TAA aneurysms were complicated by severe aortic regurgitation (AR) in half (50.3%) of the patients, 25.8% had moderate AR and 14.3% of patients had mild AR. The left ventricular ejection fraction was reduced at 46.9±12.7% compared to controls (P=0.0000). Aortic CS was markedly reduced compared to controls (4.5±4.0% vs 10.3±4.37%, P=0.000). Left ventricular longitudinal strain (−13.9±3.9% vs −18.1±6.7%,P=0.000001), basal CS (−13.9±5.6% vs −17.9±5.8%, P=0.00008) and apical CS (−18.7±8.5% vs −30.6±3.8%,p = 0.0016) were all significantly reduced compared to controls. Majority (&amp;gt;50%) of the patients were on diuretic and anti-remodeling therapy for heart failure. Surgery was performed in 29.4% of patients. The overall estimated mortality was 7.9 %. Conclusion TAA aneurysms associated with hypertension and HIV are common in this population, and are associated with considerable morbidity and mortality. CS of the aneurysmal aorta was significantly reduced translating into stiffer aortas, possibly at risk for further dilation and dissection.

Two-dimensional echocardiographic and strain values of the proximal thoracic aorta in a normal sub-Saharan African population

BackgroundThere is limited data regarding reference ranges for aortic dimensions in African populations. This study aims to establish normal reference ranges for echocardiographic dimensions and circumferential strain (CS) of the proximal thoracic aorta in a healthy sub-Saharan African population.MethodsThis was a secondary analysis of data from a prospective cross-sectional study of 88 participants conducted at Chris Hani Baragwanath Hospital (2017–2019). Aortic measurements were obtained as per the 2015 American Society of Echocardiography guidelines using a Philips iE33 system. Circumferential Strain was measured using Philips QLAB version 11.0 software offline semi-automated analysis of speckle-based strain 2-D speckle-tracking software (Amsterdam, The Netherlands).ResultsMean age was 37.22 ± 10.79 years (41% male). The mean diameter at the aortic annulus, sinuses, sino-tubular junction (STJ) and ascending aorta (AAO) were 19.11 ± 2.38 mm, 27.40 ± 6.11 mm, 25.32 ± 3.52 mm and 25.36 ± 3.38 mm, respectively. Males had larger absolute and indexed aortic diameters at all levels when compared to females. The mean aorta CS was 11.97 ± 5.05%. There was no significant difference in CS based on gender (12.19 ± 5.04% vs 11.51 ± 5.02%, P = 0.267). On multivariate linear regression analysis, male sex was the most significant predictor of increased diameter at the level of the aortic annulus (r = 0.17, P = 0.014), body surface area was the most significant predictor at the sinuses (r = 0.17, P = 0.014) and AAO (r = 0.30, P < 0.001), while age was the most significant predictor at the STJ (r = 0.27, P = 0.004). There was a negative correlation between age and aortic CS (r = − 0.12, P < 0.001). The most important predictor of aorta CS was age, on multivariate analysis (r = − 0.19, P = 0.024).ConclusionsThis study provides normal reference ranges for dimensions of the proximal aorta and circumferential strain (CS) in a sub-Saharan African population according to age, sex, and body habitus. It serves as a platform for future larger studies and allows for risk stratification of cardiovascular disease in an African population.

The association between cardiac magnetic resonance-derived aortic stiffness parameters and aortic dilation in young adults with bicuspid aortic valve: With and without coarctation of aorta

BackgroundBicuspid aortic valve (BAV) is associated with progressive aortic dilation. Studies in aortopathies have shown a correlation between increased aortic stiffness and aortic dilation. We aimed to evaluate aortic stiffness measures as predictors of progressive aortic dilation by cardiac magnetic resonance (CMR) in BAV patients. MethodsThis is a retrospective study of 49 patients with BAV (median age 21.1 years at first CMR visit) with ≥2 CMR at the Wisconsin Adult Congenital Heart Disease Program (WAtCH). Circumferential aortic strain, distensibility, and β-stiffness index were obtained from CMR-derived aortic root cine imaging, and aortic dimensions were measured at aortic root and ascending aorta. A linear mixed-model and logistic regression were used to identify important predictors of progressive aortic dilation. ResultsOver a median of 3.8 years follow-up, the annual growth rates of aortic root and ascending aorta dimensions were 0.25 and 0.16 mm/year, respectively. Aortic strain and distensibility decreased while β-stiffness index increased with age. Aortic root strain and distensibility were associated with progressive dilation of the ascending aorta. Baseline aortic root diameter was an independent predictor of >1 mm/year growth rate of the aortic root (adjusted OR 1.34, 95 % CI 1.03–1.74, p = 0.028). Most patients (61 %) had coexisting coarctation of aorta. Despite the higher prevalence of hypertension in patients with aortic coarctation, hypertension or coarctation had no effect on baseline aorta dimensions, stiffness, or progressive aortic dilation. ConclusionSome CMR-derived aortic stiffness parameters correlated with progressive aortic dilation in BAV and should be further investigated in larger and older BAV cohorts.

Assessment of the Global and Regional Circumferential Strain of Abdominal Aortic Aneurysm with Different Size by Speckle-Tracking Echocardiography.

We aimed to use speckle-tracking echocardiography (STE) to quantify circumferential aortic strain of abdominal aortic aneurysms (AAA) with different size. A total of 87 AAA patients were included. The morphological variables, including aortic maximum diameter (MD), end systolic area (ESA), end diastolic area (EDA), and thickness and area of intraluminal thrombus (ILT), were measured by ultrasound. STE was applied to calculate circumferential strain (CS) at 6 equally divided segments of the aorta at MD. We evaluated the mean value of peak strain along the 6 segments as global circumferential strain (GCS). Large AAA (≥5.5 cm) patients had higher MD, ESA, EDA, AAA length, ILT thickness, and area, but lower fractional area change, GCS, and segmental CSs than small AAA (<5.5 cm) subjects (all P< .05). Compared with AAA <4.5 cm group, AAA patients ≥4.5 cm possessed increased MD, ESA, EDA, AAA length, ILT thickness, and area, which results were also reflected in the comparison between AAA <6.5 and ≥6.5 cm group. In small AAA patients, GCS and regional strains in CS1, CS3, and CS5 segments were lower in AAA subjects ≥4.5 cm than those <4.5 cm (all P<.05). However, no significant differences in the GCS and regional CS between ≥6.5 and <6.5 cm group were found. Correlation analysis revealed a significant negative association of GCS with MD, ESA, and EDA, even after adjusting the potential confounding factors (all P< .05). Our findings may yield insight into the structural strain characteristics of AAA wall with different size, which adds the benefit of using simple echocardiography-derived biomechanics to stratify AAA patients.

Differential Effects of Aortic Valve Replacement on Aortic Circumferential Strain in Aortic Stenosis and Aortic Insufficiency

Aortic valve replacement (AVR) potentially can modify pulse-wave propagation to the distal aorta. Echo-derived global circumferential strain (GCS) was used to test whether AVR for aortic stenosis (AS) or aortic insufficiency (AI) resulted in differential aortic biomechanics in the descending thoracic aorta. This was a prospective observational study of patients who underwent cardiac surgery between 2016 and 2019. Weill Cornell Medicine, a single large academic medical center. The population comprised 48 patients undergoing AVR (62 ± 15 y/o, 79% male; 22 with AI and 26 with AS) and 11 patients undergoing coronary bypass surgery as controls. Elective cardiac surgery, transesophageal echocardiography (TEE), pulmonary artery catheter. Pre- and postprocedural TEEs were collected. Descending aorta short-axis images were analyzed for GCS, time-to-peak strain, aortic end-diastolic, end-systolic area, and fractional area changes. Pulse pressure (PP) and stroke volume were quantified. Preprocedural GCS significantly differed between patients with AI and AS, with AI patients having greater GCS (median/interquartile range, 9.6 95.3,13.6) than patients with AS (4.3 [3.4-5.1]). After AVR, in AI patients, strain significantly decreased (5.5 [3.8,8.2], p = 0.001), along with PP (mean ± standard deviation) (66.4 ± 0.8 to 54.1 ± 13.7, p < 0.001), and PP corrected strain did not (GCS/PP = 14.8 [6.9-19.9] v 12.7[8.2-18.6], p = 0.34). In AS patients, GCS significantly increased after AVR to (5.45 [4.2-6.8], p = 0.003), as did PP-corrected strain (6.9 [5.8-9.2] v 9.7 [6.5-13.4], p = 0.016). Surgical AVR produced decrements in time-to-peak strain in AI and AS groups (both p < 0.001). After AVR for AI and AS, the direction of change in distal aortic strain from baseline depends on valve pathology. This finding may have important clinical implications in terms of indication for surgery and postoperative surveillance, especially in patients with aortopathies.

Descending aortic strain quantification by intra-operative transesophageal echocardiography: Multimodality validation via cardiovascular magnetic resonance.

Whereas cardiac magnetic resonance (CMR) imaging provides high temporal resolution imaging of aortic distensibility (strain), transesophageal echocardiography (TEE) is widely used for intra-operative aortic imaging and provides a clinical alternative for aortic assessment. We tested intra-operative global circumferential aortic strain (GCS) measured on TEE in relation to the reference of CMR-derived strain among patients undergoing surgical graft repair of ascending aortic aneurysms. CMR (3T) was prospectively performed in patients scheduled for aortic repair. TEE was performed intra-operatively; images were co-localized with MRI. GCS on CMR and TEE was quantified independently, blinded to results of the other modality. 25 patients (54±10year-old, 88% male) were studied, inclusive of 13 genetically mediated and 12 degenerative aneurysms: CMR and TEE were performed within 12±9days. Pulse pressure (PP)-adjusted descending aortic TEE-derived GCS strongly correlated with cine-CMR-derived GCS (r=.75, P=.002) though absolute GCS and PP-adjusted values were slightly lower (5.40±1.11 vs 6.49±1.43% and 11.55±3.04 vs 13.99±4.53%, respectively). Similarly, TEE yielded slightly lower end-diastolic area (EDA [5.1±1.7cm2 vs 5.8±1.3cm2 , P=.004]) and end-systolic area (ESA [6.1±1.9cm2 vs 6.5±1.7cm2 , P=.10]), with significant correlations between the two modalities (r=.73, .76, P<.05 for all). This exploratory study supports feasibility of TEE for assessing aortic GCS in a surgical at-risk population, as well as magnitude of agreement between intra-operative TEE and preoperative CMR. We found that there is a significant correlation between GCS and EDA and ESA aortic areas, but that TEE-derived parameters underestimated CMR values by a small but significant amount.

Immediate of Impact Prosthetic Graft Replacement of the Ascending Aorta on Circumferential Strain in the Descending Aorta

Prosthetic replacement of the ascending aorta (AA) can potentially modify energy propagation to the distal aorta and contribute to adverse aortic remodelling. This preliminary study employed intra-operative transoesophageal echocardiography (TOE) to assess the immediate impact of prosthetic graft replacement of the AA on circumferential strain in the descending aorta. Intra-operative TOEs in patients undergoing AA graft replacement were analysed for circumferential strain, fractional area change (FAC), dimensions (end diastolic area [EDA], and end systolic area [ESA]) in the descending aorta immediately before and after graft replacement. Deformation was assessed via global peak circumferential aortic strain (CAS), together with pulse pressure corrected strain, time to peak strain (TTP), and aortic distensibility. Forty-five patients undergoing AA replacement with prosthetic graft (91% elective) were studied. Following grafting, descending thoracic aortic circumferential strain increased (6.3 ± 2.8% vs. 8.9 ± 3.4%, p = .001) paralleling distensibility (5.7 [3.7–8.6] 10−3 mmHg vs. 8.5 [6.4–12.4] 10−3 mmHg, p < .001). Despite slight increments in post graft left ventricular ejection fraction (LVEF) (52.3 ± 10.8% vs. 55.0 ± 11.9, p < .001), stroke volume was similar (p = .41), and magnitude of increased strain did not correlate with change in stroke volume (r = −.03, p = .86), LVEF (r = .18, p = .28), or pulse pressure (r = .28, p = .06). Descending aortic size (EDA 4 [2.7–4.6] cm2vs. 3.7 [2.5–5] cm2, p = .89; ESA 4.3 [3.2–5.3] cm2vs. 4.5 [3.3–5.8] cm2, p = .14) was similar pre- and post graft. In subgroup analysis, patients with cystic medial necrosis had a significantly higher post procedure CAS than patients with atherosclerotic aneurysms (9.7 ± 3.5% vs. 7.0 ± 2.3%, p = .03). Prosthetic graft replacement of the AA increases immediate aortic circumferential strain of the descending aorta, particularly in patients with cystic medial necrosis. Our findings suggest that grafts augment energy transfer to the distal aorta, a potential mechanism for progressive distal aortic dilation and/or dissection.

Immediate Impact of Prosthetic Graft Replacement of the Ascending Aorta on Circumferential Strain in the Descending Aorta

Prosthetic replacement of the ascending aorta (AA) can potentially modify energy propagation to the distal aorta and contribute to adverse aortic remodelling. This preliminary study employed intra-operative transoesophageal echocardiography (TOE) to assess the immediate impact of prosthetic graft replacement of the AA on circumferential strain in the descending aorta. Intra-operative TOEs in patients undergoing AA graft replacement were analysed for circumferential strain, fractional area change (FAC), dimensions (end diastolic area [EDA], and end systolic area [ESA]) in the descending aorta immediately before and after graft replacement. Deformation was assessed via global peak circumferential aortic strain (CAS), together with pulse pressure corrected strain, time to peak strain (TTP), and aortic distensibility. Forty-five patients undergoing AA replacement with prosthetic graft (91% elective) were studied. Following grafting, descending thoracic aortic circumferential strain increased (6.3±2.8% vs. 8.9±3.4%, p=.001) paralleling distensibility (5.7 [3.7-8.6] 10-3mmHg vs. 8.5 [6.4-12.4] 10-3mmHg, p<.001). Despite slight increments in post graft left ventricular ejection fraction (LVEF) (52.3±10.8% vs. 55.0±11.9, p<.001), stroke volume was similar (p=.41), and magnitude of increased strain did not correlate with change in stroke volume (r=-.03, p=.86), LVEF (r=.18, p=.28), or pulse pressure (r=.28, p=.06). Descending aortic size (EDA 4 [2.7-4.6] cm2vs. 3.7 [2.5-5] cm2, p=.89; ESA 4.3 [3.2-5.3] cm2vs. 4.5 [3.3-5.8] cm2, p=.14) was similar pre- and post graft. In subgroup analysis, patients with cystic medial necrosis had a significantly higher post procedure CAS than patients with atherosclerotic aneurysms (9.7±3.5% vs. 7.0±2.3%, p=.03). Prosthetic graft replacement of the AA increases immediate aortic circumferential strain of the descending aorta, particularly in patients with cystic medial necrosis. Our findings suggest that grafts augment energy transfer to the distal aorta, a potential mechanism for progressive distal aortic dilation and/or dissection.

Aortic Strain Correlates with Elastin Fragmentation in Fibrillin-1 Hypomorphic Mice.

Background: High-frequency ultrasound has facilitated in vivo measurement of murine ascending aorta, allowing aortic strain to be determined from 2-D imaging. Thoracic aortic aneurysms associated with mutations in fibrillin-1 (FBN1) display elastin fragmentation, which may affect aortic strain. In this study, we determined the relationship between elastin fragmentation and aortic circumferential strain in wild-type (WT) and fibrillin-1 hypomorphic (FBN1mgR/mgR) mice.Methods and Results: Luminal diameter of the ascending aorta from WT and FBN1mgR/mgR mice was measured in systole and diastole. Expansion of the ascending aorta during systole in male and female WT mice was 0.21±0.02 mm (16.3%) and 0.21±0.01 mm (17.0%), respectively, while expansion in male and female FBN1mgR/mgR mice was 0.11±0.04 mm (4.9%) and 0.07±0.02 mm (4.5%), respectively. Reduced circumferential strain was observed in FBN1mgR/mgR mice compared with WT littermates. Elastin fragmentation was inversely correlated to circumferential strain (R2=0.628, P=0.004) and significantly correlated with aortic diameter (systole, R2=0.397, P=0.038; diastole, R2=0.515, P=0.013).Conclusions: FBN1mgR/mgR mice had increased aortic diameter, reduced circumferential strain, and increased elastin fragmentation. Elastin fragmentation in FBN1mgR/mgR and their WT littermates was correlated with reduced circumferential strain.

GW28-e0644 Quantitative Measurement of Circumferential Aortic Strain by 2D Speckle Tracking Echocardiography improves Diagnostics of Coronary Artery Stenosis in suspected patients

Two-dimensional speckle tracking echocardiography (2D-STE) detects early signs of ascending aorta stiffness; however, it is unknown whether aortic strain analysis at rest in suspected patients with coronary artery disease (CAD) predicts the stenosis of the coronary artery. The aim of present study

Aortic arch mechanics measured with two-dimensional speckle tracking echocardiography.

To study the feasibility of vascular mechanics at the aortic arch with two-dimensional speckle tracking echocardiography, as well as to define normal values and to compare results between hypertensive patients and healthy patients. We included 107 patients (61 healthy patients and 46 hypertensive patients) who underwent a complete echocardiographic exam, including a short-axis view of the aortic arch. The speckle tracking methodology was used to calculate aortic arch mechanics offline (EchoPAC; GE Healthcare). The analysis was performed for circumferential aortic strain and for the early circumferential aortic strain rate, and we used an average result of the six equidistant segments of the arterial wall. We also assessed the aortic pulse wave velocity with the Complior method. The 61 healthy patients had a mean age of 33 ± 9 years, and 59% were women. Of the total 366 aortic arch wall segments, 344 (94%) had adequate waveforms for the speckle tracking analysis. The hypertensive patients had a mean age of 45 ± 12 years, and 54% were women. Of the total 276 aortic wall segments, 261 (95%) had adequate waveforms for analysis. Aortic arch strain and strain rate were lower in the hypertensive patients group than in the healthy patients group (6.3 ± 2.0 vs. 11.2 ± 3.2% and 1.0 ± 0.3 vs. 1.5 ± 0.4 s(-1), respectively, both P < 0.01). Aortic arch strain and strain were correlated with age (r = -0.62, r = -0.54; P < 0.01), pulse pressure (r = -0.48, r = -0.39; P < 0.01) and the pulse wave velocity (r = -0.57, r = -0.54; P < 0.01). After adjustments for age, sex and BMI, strain was significantly lower in hypertensive patients, when compared with healthy patients. Speckle tracking analysis of aortic arch images is feasible and might serve as a new approach to evaluate arterial function.

Descending aortic mechanics and atrial fibrillation: a two-dimensional speckle tracking transesophageal echocardiography study.

Vascular mechanics assessed with two-dimensional speckle tracking echocardiography (2D-STE) could be used as a new imaging surrogate of vascular stiffening. The CHA2DS2-VASc score is considered accurate as an estimate of stroke risk in non-valvular AF, although many potential stroke risk factors have not been included in this scoring method. The purpose of this research is to study the feasibility of evaluating vascular mechanics at the descending aorta in non-valvular AF patients using transesophageal 2D-STE and to analyze the association between descending aortic mechanics and stroke. We prospectively recruited a group of 44 patients referred for a transesophageal echocardiogram (TEE) in the context of cardioversion for non-valvular AF. A short-axis view of the descending aorta, one to two centimeters after the aortic arch was selected for the vascular mechanics assessment with the 2D-STE methodology. The vascular mechanics parameters analyzed were circumferential aortic strain (CAS) and early circumferential aortic strain rate (CASR). A clinical assessment was performed with focus on the past stroke history and the CHA2DS2-VASc score. The mean age of our cohort was 65 ± 13years and 75% were men; AF was known for 2.8 ± 2.5years and it was considered paroxystic in 41% of cases. Waveforms adequate for measuring 2D-STE were present in 85% of the 264 descending aortic wall segments. The mean CAS was 3.5 ± 1.2% and the mean CASR was 0.7 ± 0.3s-1. The inter- and intra-observer variability for aortic mechanics was considered adequate. The median CHA2DS2VASc score was 2 (2-3). As the score increased we noted that both the CAS (r = -0.38, P = 0.01) and the CASR (r = -0.42, P < 0.01) decreased. Over 16% of the AF patients had a past history of stroke. These patients had lower values of both descending aortic strain [2.2 (1.8-2.6) vs. 3.9 (3.3-4.9)%, P < 0.01] and strain rate [0.4 (0.3-0.4) vs. 0.7 (0.6-1.1)s-1, P < 0.01]. CAS remained independently associated with a past history of stroke after adjustment for the CHA2DS2VASc score. Our data showed that non-valvular AF patients with a past history of stroke had lower values of aortic mechanics assessed with transesophageal 2D-STE.

PP.32.06

Objective: Our groups has previously demonstrated that aortic arch mechanics with 2D-speckle tracking (2D-ST) echocardiography was a feasible methodology. We have proved that hypertensive patients had lower values of vascular mechanics when compared to an age-matched control group. We have also demonstrated a significant association of aortic arch mechanics with aortic stiffness. To assess the influence of aortic arch mechanics in the left ventricular (LV) hypertensive remodelling process. Design and method: We included 46 consecutive patients with hypertension and performed a complete echocardiographic exam. We included a high frame rate, short axis view of the aortic arch. The 2D-ST methodology was used to off-line calculate aortic arch mechanics (EchoPAQ, GE Healthcare®). The aortic arch mechanics parameters analyzed were circumferential aortic strain (CAS) and early circumferential aortic strain rate (CASR). The LV mass was calculated according to the Devereux's formula. We divided our sample in two groups: Group A (normal LV mass) n = 34; Group B (elevated LV mass) n = 12. Results: Mean age was 45 ± 12 years with a gender balance. Patients had hypertension for a median time of 5 (2 – 8) years, and were medicated with a median of 2 (1 -3) drugs. There were no difference between groups regarding gender, blood pressure and heart rate. Left ventricular systolic function, aortic dimensions, systemic arterial compliance and the Beta1 index (4.8 ± 3.3 vs 4.3 ± 1.9) were also similar. Group B patients were older, had a higher left atrial volume (28 ± 6 vs 33 ± 7 ml/m2, p = 0.02) and lower myocardial relaxation velocities. CAS (6.7 ± 2.1 vs 5.0 ± 1.0%, p < 0.01) and CASR (1.0 ± 0.3 vs 0.8 ± 0.3s1,p = 0.049) were also lower for the Group B patients. A CAS < 6.1% had a sensitivity of 91.7% and a specificity of 61.8% for an increase in indexed LV mass. CAS (area under curve [AUC] 0.77) had a superior accuracy than Beta1 index (AUC 0.5, pairwise comparisons of ROC curves p = 0.02) and the pulse pressure (AUC 0.52, pairwise comparisons of ROC curves p < 0.01) to estimate an increase in LV mass. Conclusions: Our investigation proved the association aortic arch vascular mechanics with the LV remodelling process.

Longitudinal and circumferential strain of the proximal aorta.

BackgroundAccurate assessment of mechanical properties of the proximal aorta is a requisite first step for elucidating the pathophysiology of isolated systolic hypertension. During systole, substantial proximal aortic axial displacement produces longitudinal strain, which we hypothesize causes variable underestimation of ascending aortic circumferential strain compared to values in the longitudinally constrained descending aorta.Methods and ResultsTo assess effects of longitudinal strain, we performed magnetic resonance imaging in 375 participants (72 to 94 years old, 204 women) in the Age, Gene/Environment Susceptibility‐Reykjavik Study and measured aortic circumferential and longitudinal strain. Circumferential ascending aortic area strain uncorrected for longitudinal strain was comparable in women and men (mean [95% CI], 8.3 [7.8, 8.9] versus 7.9 [7.4, 8.5]%, respectively, P=0.3). However, longitudinal strain was greater in women (8.5±2.5 versus 7.0±2.5%, P<0.001), resulting in greater longitudinally corrected circumferential ascending aortic strain (14.4 [13.6, 15.2] versus 13.0 [12.4, 13.7]%, P=0.010). Observed circumferential descending aortic strain, which did not require correction (women: 14.0 [13.2, 14.8], men: 12.4 [11.6, 13.2]%, P=0.005), was larger than uncorrected (P<0.001), but comparable to longitudinally corrected (P=0.12) circumferential ascending aortic strain. Carotid‐femoral pulse wave velocity did not correlate with uncorrected ascending aortic strain (R=−0.04, P=0.5), but was inversely related to longitudinally corrected ascending and observed descending aortic strain (R=−0.15, P=0.004; R=−0.36, P<0.001, respectively). Longitudinal strain was also inversely related to carotid‐femoral pulse wave velocity and other risk factors for higher aortic stiffness including treated hypertension.ConclusionsLongitudinal strain creates substantial and variable errors in circumferential ascending aortic area strain measurements, particularly in women, and should be considered to avoid misclassification of ascending aortic stiffness.

Longitudinal and circumferential strain of the proximal aorta

Background-—Accurate assessment of mechanical properties of the proximal aorta is a requisite first step for elucidating the pathophysiology of isolated systolic hypertension. During systole, substantial proximal aortic axial displacement produces longitudinal strain, which we hypothesize causes variable underestimation of ascending aortic circumferential strain compared to values in the longitudinally constrained descending aorta.

Thoracic aortic circumferential strain and atherosclerosis in patients with cerebral infarction

Thoracic aortic circumferential strain and atherosclerosis in patients with cerebral infarction

Catalase overexpression in aortic smooth muscle prevents pathological mechanical changes underlying abdominal aortic aneurysm formation

The causality of the associations between cellular and mechanical mechanisms of abdominal aortic aneurysm (AAA) formation has not been completely defined. Because reactive oxygen species are established mediators of AAA growth and remodeling, our objective was to investigate oxidative stress-induced alterations in aortic biomechanics and microstructure during subclinical AAA development. We investigated the mechanisms of AAA in an angiotensin II (ANG II) infusion model of AAA in apolipoprotein E-deficient (apoE(-/-)) mice that overexpress catalase in vascular smooth muscle cells (apoE(-/-)xTg(SMC-Cat)). At baseline, aortas from apoE(-/-)xTg(SMC-Cat) exhibited increased stiffness and the microstructure was characterized by 50% more collagen content and less elastin fragmentation. ANG II treatment for 7 days in apoE(-/-) mice altered the transmural distribution of suprarenal aortic circumferential strain (quantified by opening angle, which increased from 130 ± 1° at baseline to 198 ± 8° after 7 days of ANG II treatment) without obvious changes in the aortic microstructure. No differences in aortic mechanical behavior or suprarenal opening angle were observed in apoE(-/-)xTg(SMC-Cat) after 7 days of ANG II treatment. These data suggest that at the earliest stages of AAA development H(2)O(2) is functionally important and is involved in the control of local variations in remodeling across the vessel wall. They further suggest that reduced elastin integrity at baseline may predispose the abdominal aorta to aneurysmal mechanical remodeling.

Aortic stiffness is strikingly increased with age ≥50 years in clinically normal individuals and preclinical patients with cardiovascular risk factors: Assessment by the new technique of 2D strain echocardiography

Various measures of aortic stiffness have been proposed as cardiovascular risk markers, but interest has now shifted to more direct and easier evaluation of aortic function. The present study was conducted to determine the feasibility of measuring aortic stiffness (β) with two-dimensional (2D) strain echocardiography and the impact of age and gender on preclinical atherosclerosis. The peak circumferential strain of the abdominal aorta was measured using 2D strain echocardiography, and β was determined in 54 clinically normal individuals and 104 patients with cardiovascular risk factors and no evidence of cardiovascular disease. The β correlated significantly with age in all 158 patients. However, the relationship was nonlinear, and β was markedly greater in patients ≥ 50 years. In 54 clinically normal individuals, the relationship was comparatively linear. The systolic blood pressure and pulse pressure were significantly greater in patients ≥ 50 years. There were no significant differences in β and blood pressure parameters between genders. The β increased dramatically with advanced age (≥ 50 years), regardless of gender, in clinically healthy and community-based patients with cardiovascular risk factors. The aortic circumferential strain was measured with 2D strain echocardiography which is a new tool that can be used to directly and easily evaluate aortic stiffness.