Change In Aortic Diameter Research Articles

Abstract 14: T Cells Mediate Angiotensin II-induced Aortic Stiffening

Clinical studies show an association between inflammation and arterial stiffness. We and others have shown that T cells are involved in hypertension; however their role in aortic stiffening is unknown. We hypothesized that T cells mediate angiotensin II-induced aortic stiffening. Using a pressurized myograph system, we determined aortic stiffness and quantified this using a distensibility index (DI), defined as the percent change in aortic outer diameter from 75 mmHg to 125 mmHg. Angiotensin II (490ng/kg/min for 14 days) markedly decreased the distensibility index in C57Bl/6 mice (23.8±5.5 v.s. 8.9±4.1, p<0.01, n=8), and this was almost completely prevented in RAG-1 -/- mice (18.3±4.0, p<0.01 compared with C57Bl/6, n=8). Adoptive transfer of pan T cells into RAG-1 -/- mice restored aortic stiffness in RAG-1 -/- (11.9±2.6, p<0.05, n=5). The effect of T cell-derived pro-inflammatory cytokines on aortic stiffening was examined using interferon-γ (IFN-γ -/- ) and IL-6 -/- mice. Deficiency of INF-γ partially restored aortic distensibility (17.0±3.5 v.s. 8.9±4.1, p<0.01, n=8) compared C57Bl/6 mice treated with angiotensin II. Aortic distensibility was also preserved in IL-6 -/- mice (19.9±5.9 v.s. 8.9±4.1, p<0.01, n=8) treated with angiotensin II. In contrast to these functional alterations, the increase in collagen caused by angiotensin II was similar between wild-type and RAG-1 -/- mice. There was no change in elastin abundance with angiotensin II treatment or in different mouse strains. In conclusion, T cells are essential for angiotensin II-induced collagen deposition, vascular hypertrophy and aortic stiffening. Part of these effects could be mediated by pro-inflammatory cytokines such as INF-γ and IL-6. These likely mediate aortic stiffening by altering properties of elastin and collagen such as crosslinking, rather than alter total abundance of these proteins.

Changes in aortic shape and diameters after death: Comparison of early postmortem computed tomography with antemortem computed tomography

PurposeThe purpose of this study is to evaluate the postmortem deformation of the aorta on postmortem computed tomography (CT) by comparison with the antemortem CT in the same patient. Materials and methodsA total of 58 non-traumatic patients without hemorrhagic events who underwent torso CT before and shortly after death were enrolled. Antemortem chest and abdominal CT were obtained in 44 cases and in 57 cases, respectively. The lengths of the major and minor axes of the ascending and descending thoracic aorta and the abdominal aorta were measured on both antemortem and postmortem CT in the same patient. To evaluate the shape of the aorta, the major axis–minor axis ratio (Ma-MiR) was calculated. Mean values of the diameters of the aorta and Ma-MiRs on postmortem CT were compared with those on antemortem CT using the Wilcoxon signed-rank test. We also evaluated the major and minor axes and Ma-MiRs on both antemortem and postmortem CT in two age groups: 65 years and under (n=13) and over 65 years (n=45). ResultsAt each level tested, the aorta significantly shrank after death (p<0.001) (ascending thoracic aorta, descending thoracic aorta, and abdominal aorta: 38.5mm×33.5mm, 28.0mm×25.9mm, and 24.4mm×21.8mm on antemortem CT, 30.0mm×26.2mm, 24.4mm×20.7mm, and 21.5mm×14.5mm on postmortem CT, respectively). The postmortem Ma-MiRs significantly increased at the descending thoracic aorta and the abdominal aorta (p<0.001). The diameters of the aorta are longer in older cases at all levels on both antemortem and postmortem CT. The reduction rates were larger in younger cases than older cases at all levels. ConclusionsAfter death, the aorta shrunk at all levels, and became oval in shape in descending thoracic and abdominal aorta. The contraction was greater in younger cases than older cases. Investigators who interpret postmortem imaging should be aware of the postmortem deformation of the aorta.

Patient outcomes and thoracic aortic volume and morphologic changes following thoracic endovascular aortic repair in patients with complicated chronic type B aortic dissection

True and false lumen changes and patient outcomes following thoracic endovascular aortic repair (TEVAR) for patients with stable type B dissection have been described by the The Investigation of Stent Grafts in Aortic Dissection (INSTEAD) trial. However, these changes have not been described in TEVAR patients treated for complications of chronic dissection. A single-institution study was conducted of 73 prospectively evaluated patients treated for complications of chronic type B dissection from 2002 to 2010. Spiral computed tomography reconstructions using M2S (Medical Media Systems, West Lebanon, NH) were analyzed for sequential changes in aortic volume and diameter during patient follow-up. Changes in aortic volume and diameter were tabulated as a percent change from preoperative values. Patient outcomes were determined by sequential evaluations postprocedure. TEVAR was successfully performed in 72 out of the 73 patients (99%). Indications for intervention were aortic enlargement (n = 62), failure of medical management (n = 7), and perforation (n = 4). The 30-day all-cause mortality rate was 14%; events were due to retrograde dissection (n = 4), cardiac-related (n = 4), and rupture (n = 2). Eleven out of the 72 patients (15%) required a secondary procedure for endoleak (n = 7) and persistent distal perfusion of the false lumen (n = 4). Mean percentage expansion of the thoracic true lumen was noted during the follow-up period: 38%, 46%, 71%, and 114% at 1-, 3-, 6-, and 12-month follow-up, respectively. Concomitant regression of the thoracic false lumen of -65%, -68%, -84%, and -84% was observed at the same intervals, respectively. Patients with an initial extension of the thoracic dissection into the infrarenal aorta (n = 46) had an increase in mean percentage change of aortic diameter and volume to 21% and 17% at 1 year, respectively. By contrast, in the patient group without infrarenal dissection (n = 14), the infrarenal aortic diameter and volume remained relatively unchanged at 3% and -0.9%, respectively, at 1-year postintervention. TEVAR is a potential treatment option for patients experiencing complications of chronic type B dissection. During follow-up, there is a predictable expansion of the thoracic true lumen and regression of the thoracic false lumen. These findings correlate with those of the INSTEAD trial, which demonstrated false lumen regression and true lumen expansion in a cohort of patients with stable type B dissection. However, many patients with extension of thoracic dissection into the infrarenal aorta demonstrate continued aortic dilation and, on occasion, the need for secondary intervention for persistent distal perfusion. Further analysis is needed in this subgroup of patients so as to better determine potential predictors and the clinical significance of post-TEVAR infrarenal expansion. Moreover, further investigations may support a role for secondary endovascular intervention in remedying persistent infrarenal aortic expansion after TEVAR for chronic dissection.

Extent of Degenerative Changes in Ascending Aorta of Patients with Bicuspid Aortic Valve (BAV)—A Histopathological Study

Objective: To find out, whether the degenerative process of ascending aorta is limited to the aortic sinuses only or is extending to mid and distal ascending aorta of Bicuspid Aortic Valve patients. Method: A prospective consecutive study on 25 patients of BAV (undergoing aortic valve with ± ascending aortic surgeries) was conducted from 1st Jan 2010 to 30th Dec 2011. Morphological and anatomical data of root and ascending aorta were recorded from echocardiography and computed tomography angiography. Intra-operatively, aortic tissue biopsy taken from three sites: sinus, mid, and distal ascending aorta. Histological evaluation of the aortic wall was based on criteria adapted from Schlatmann and Becker and from de Sa et al. The presence and degree of the 5 variables of degeneration were studied: Linear regression and correlation were used to get relationship between histopathological scoring (HPE-T) and aortic diameter for each site of ascending aorta. Results: Significant linear relation was found between aortic sinus diameter and HPE T score with R value = 0.590 (p value 0.001) and variance of 37.5%. Analysis suggests that HPE T Score = -5.139 + (0.188 x Ao. Sinus Diameter in mm). No significant linear relation could be established between mid and distal ascending aorta diameter and HPE T scoring. Conclusion: In BAV patient’s, a definite relationship between degenerative changes of aortic media and aortic diameter was found and was limited up to the sinus level only. Thus, the study reinforces the thought of replacing aortic sinus too while dealing with aortic valve, even without significant dilatation. By this aggressive management of aortic root, progression of aortic dilatation or dissection can be prevented in bicuspid aortic valve patients.

Abstract 18212: Relationship Between Aortic Distensibility and Coronary Blood Flow in Patients with Ascending Thoracic Aortic Aneurysm

Introduction: We have observed coronary slow flow in patients with aortic aneurysms in the absence of coronary artery disease (CAD). Other observations have identified that aortic wall distensibility influences coronary blood flow. In order to further evaluate this phenomenon, we sought to study the relationship between aortic distensibility and coronary blood flow among the patients with ascending thoracic aortic aneurysms (ATAA). Methods: Evaluation of consecutive patients referred for surgical repair of ATAA who had non- obstructive CAD (&lt;40% stenosis) as evaluated by coronary angiography. Aortic distensibility was calculated from aortograms using the formula D = 2 x (change in aortic diameter) / (diastolic aortic diameter) x (change in aortic pressure). Coronary blood flow was measured in all major coronary arteries by calculating TIMI frame count. Spearman rank correlation test was performed to evaluate the correlation between aortic distensibility and TIMI frame counts for the three major coronary arteries. Results: Out of 96 patients with angiographic slow flow, 89 (92.7%) patients had involvement of the ascending aorta with or without arch and/or descending aorta and non-obstructive CAD. Analysis of the 89 ATAA patients showed a significant correlation between decreased ascending aortic distensibility and prolonged TIMI frame count in all the three coronary arteries. Correlation coefficient between ascending aortic distensibility and LAD flow is r = -0.23, p = 0.03, LCX is r = -0.28, p = 0.007, RCA is r = -0.30, p = 0.005. A significant inverse correlation, r = -0.23, p = 0.04 is also observed between aortic arch distensibility and LAD flow. Conclusion: As the distensibility of the aorta decreases in patients with thoracic aortic aneurysm, the coronary blood flow also decreases. Our study for the first time shows that among the patients with thoracic aortic aneurysms, aortic distensibility does impact coronary blood flow in the absence of significant CAD, possibly through alteration in coronary blood flow mechanics and microvascular dysfunction. The clinical impact of this finding warrants further studies.

Aortic remodeling, volumetric analysis, and clinical outcomes of endoluminal exclusion of acute complicated type B thoracic aortic dissections

Structural changes within the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B thoracic aortic dissections (ABAD) remain unknown. This study reviewed and analyzed morphologic changes, volumetric data, and clinical outcomes of patients with ABAD. Forty-one consecutive patients with ABAD, all with the volumetric analysis of aortic luminal changes and ≥1 year of follow-up, were treated as a part of a single-center U.S. Food and Drug Administration (FDA)-approved investigational device exemption (IDE) trial from 2002 to 2009. Indications were malperfusion in 17, rupture in 12, chest pain in 6, acute enlargement in 4, and uncontrolled hypertension in 2. Duration of symptoms was ≤14 days. Three-dimensional M2S computed tomography reconstructions (Medical MetRx Solutions, West Lebanon, NH) were analyzed for aortic volume and diameter changes, regression of the false lumen, and expansion of the true lumen. Emergent surgery was required in 17 (42%) patients, excluding one death at induction. Procedural success rate was 92.5%. The 30-day mortality was 4.9% for malperfusion, 4.9% for rupture, and 0% for all others, with late mortality of 0%, 9.8%, and 7.3%, respectively. Mean follow-up was 12.4 months. Permanent stroke and paraplegia rates were 4.9% (n = 2) and 0%. Ten of 12 secondary interventions were performed for 6 proximal endoleaks, 1 distal cuff endoleak, and 3 distal reperfusions. For the 33 patients without endoleaks, the true lumen volume increased by 29% at 1 month, 51% at 1 year, and 80% at 5 years. Volume regression of the false lumen was 69%, 76%, and 86%, respectively. The true lumen volume did not change at 1 month or 1 year in the endoleak group (n = 7) but increased 50% at 2 years after secondary intervention. A 10% reduction of abdominal aortic volume distal to endograft occurred over 5 years in the absence of endoleaks. TEVAR offers a promising solution to patients with ABAD. Aortic morphologic changes occur shortly after TEVAR and remain predictable up to 5 years with continuous expansion of the true lumen and regression of the false lumen. A lack of increase in the true lumen volume is associated with endoleaks or distal reperfusion.

Aortic root dimension changes during systole and diastole: evaluation with ECG-gated multidetector row computed tomography.

Cardiac pulsatility and aortic compliance may result in aortic area and diameter changes throughout the cardiac cycle in the entire aorta. Until this moment these dynamic changes could never be established in the aortic root (aortic annulus, sinuses of Valsalva and sinotubular junction). The aim of this study was to visualize and characterize the changes in aortic root dimensions during systole and diastole with ECG-gated multidetector row computed tomography (MDCT). MDCT scans of subjects without aortic root disease were analyzed. Retrospectively, ECG-gated reconstructions at each 10% of the cardiac cycle were made and analyzed during systole (30–40%) and diastole (70–75%). Axial planes were reconstructed at three different levels of the aortic root. At each level the maximal and its perpendicular luminal dimension were measured. The mean dimensions of the total study group (n = 108, mean age 56 ± 13 years) do not show any significant difference between systole and diastole. The individual dimensions vary up to 5 mm. However, the differences range between minus 5 mm (diastolic dimension is greater than systolic dimensions) and 5 mm (vice versa). This variability is independent of gender, age, height and weight. This study demonstrated a significant individual dynamic change in the dimensions of the aortic root. These results are highly unpredictable. Most of the healthy subjects have larger systolic dimensions, however, some do have larger diastolic dimensions.

Assessment of thoracic aortic elasticity: a preliminary study using electrocardiographically gated dual-source CT

To gain a new insight into the elastic properties of the thoracic aorta in patients without aortic diseases using electrocardiographically (ECG)-gated dual-source (DS) CT. 56 subjects with no cardiovascular disease, selected from 2,700 people undergoing ECG-gated DSCT examination, were divided into three groups according to their age. CT data were reconstructed in 5% step throughout the RR interval. Diameter and area were measured at the curve of the ascending aorta (AA) and at the same level of the descending aorta (DA). The pulsation and elasticity of the aorta were evaluated. Aortic diameter changes were noted throughout the cardiac cycle. The maximum average diameter was seen at an RR interval of 24.02 ± 4.99% for the AA and 25.63 ± 4.77% for the DA. The minimum was at 93.5 ± 4.04% for the AA and 96.6 ± 4.58% for the DA. There was an age-dependent decrease in elasticity, while different correlation coefficients were found between various age groups and different elastic parameters. The properties of aortic pulsation and wall elasticity could be well shown by ECG-gated DSCT. The new findings regarding segment difference and age relevance were significant and should be taken into account in clinical trials and treatments for the elasticity related cardiovascular diseases.

Pulsatile Distension of the Proximal Aneurysm Neck is Larger in Patients with Stent Graft Migration

Purpose: The proximal abdominal aortic aneurysm (AAA) neck expands significantly during the cardiac cycle, both before and after endovascular aneurysm repair (EVAR). Clinical consequences of this pulsatility were anticipated but have never been reported. This study investigated whether there is a relation between stent graft migration and preoperatively measured pulsatility of the proximal aneurysm neck. Methods: EVAR patients with a preoperative dynamic computed tomography angiography (CTA), an immediate postoperative, and a CTA at 3 years after EVAR were included. The preoperative dynamic CTAs consisted of eight images per heartbeat. Aortic diameter and area changes per heartbeat were measured at two levels: (A) 3 cm above and (B) 1 cm below the most distal renal artery. Postoperatively, the distance between the most distal renal artery and the most proximal stent graft ring was measured. Two patient groups were distinguished according to whether migration during follow-up occurred (group 1) or had not occurred (group 2). The aneurysm neck dynamics of the two groups were compared by using the t-test for unpaired data and multivariable logistic regression analyses were performed. Mean values are presented with the standard deviation. Results: Included were 26 patients (19 Talent, 6 Excluder and 1 Lifepath). Stent graft migration of ≥5 mm occurred in 11 patients (group 1). The pulsatility of the AAA neck in these patients was compared with the pulsatility in 15 patients with no graft migration (group 2). There were no significant differences in aortic neck characteristics (angulation, length and diameter) or degree of stent graft oversizing between the two groups. At level A in group 1 versus group 2, the diameter increase during the cardiac cycle was 2.0 ± 0.3 versus 1.7 ± 0.3 mm and the aortic area increase was 49 ± 15 versus 33 ± 12 mm2. At level B in group 1 versus group 2, the diameter increase per heartbeat was 1.8 ± 0.3 versus 1.6 ± 0.4 mm, and the area increase was 37 ± 10 versus 25 ± 15 mm2. The heartbeat-dependent diameter and area changes at both levels were significantly higher in group 1 compared with group 2. Multivariate regression analysis showed suprarenal aortic pulsatility was a significant predictor for stent graft migration after 3 years. Conclusion: The preoperative heartbeat-dependent aneurysm neck distension is significantly associated with stent graft migration after 3 years. The aortic pulsatility in patients with stent graft migration is significantly higher than the pulsatility in patients without stent graft migration.

The Impact of Hypovolaemic Shock on the Aortic Diameter in a Porcine Model

Objectives To investigate the impact of hypovolaemic shock on the aortic diameter in a porcine model, and to determine the implications for the endovascular management of hypovolaemic patients with traumatic thoracic aortic injury (TTAI). Materials and methods The circulating blood volume of seven Yorkshire pigs was gradually lowered in 10% increments. At 40% volume loss, an endograft was deployed in the descending thoracic aorta, followed by gradual fluid resuscitation. Potential changes in aortic diameter during the experiment were recorded using intravascular ultrasound (IVUS). Results The aortic diameter decreased significantly at all evaluated levels during blood loss. The ascending aortic diameter decreased on average with 38% after 40% blood loss (range 24–62%, p = 0.018), the descending thoracic aorta with 32% (range 18–52%, p = 0.018) and the abdominal aorta with 28% (range 15–39%, p = 0.018). The aortic diameters regained their initial size during fluid resuscitation. Conclusion The aortic diameter significantly decreases during blood loss in this porcine model. If these changes take place in hypovolaemic TTAI patients as well, it may have implications for thoracic endovascular aortic repair (TEVAR). Increased oversizing of the endograft, or additional computed tomography (CT) or IVUS imaging after fluid resuscitation for more adequate aortic measurements, may be needed in TTAI patients with considerable blood loss.

Impaired aortic elastic properties in normotensive patients with psoriasis

Objective. Psoriasis is a chronic inflammatory disease affecting approximately 1.5–3% of the general population. Several studies have demonstrated an association between psoriasis and atherosclerosis. The aim of this study is the investigate relation between aortic wall stiffness and duration and severity of the disease in patients with psoriasis. Method. The study population included 58 patients with psoriasis (27 men, mean age = 36.3 ± 10.6 years, and mean disease duration = 9.8 ± 6.7 years) and 36 healthy control subjects (17 men, and mean age = 40.0 ± 11.1 years). Aortic stiffness index, aortic strain and distensibility, were calculated from the aortic systolic and diastolic diameters measured by echocardiography and blood pressure obtained by sphygmomanometer. Cardiac functions were determined by using echocardiography, consisting of standard two-dimensional and conventional Doppler. Results. The conventional echocardiographic parameters were similar between patients and controls. There were significant differences between the control and the patient groups in aortic stiffness index (2.7 ± 1.0 vs 2.0 ± 0.8, p = 0.001), aortic strain (10.3±3.3% vs 14.2±4.5%, p <0.001) and distensibility (4.2 ± 1.7 × 10−6 cm2/dyn vs 5.8 ± 2.0 × 10−6 cm2/dyn, p=0.001). There were significant negative correlations between the disease duration and distensibility (r = −0.54, p < 0.001), aortic strain (r=−0.41, p=0.001), aortic diameter change (r = −0.35, p = 0.007) and positive correlations between the disease duration and aortic stiffness index (r = 0.58, p < 0.001). Also heart rate and high-sensitive C reactive protein were significantly higher in psoriasis patients than in healthy controls (80.0 ± 11.8 beats/min vs 72.4 ± 8.8 beats/min, p = 0.001 and 9.7 ± 21.4 mg/l vs 3.7 ± 2.1 mg/l, p = 0.04, respectively). Conclusion. Aortic stiffness measurements were found abnormal in patients with psoriasis. We have also demonstrated that there were significant correlations between aortic stiffness parameters and disease duration. This study suggests that aortic stiffness measurement could be used for assessment of cardiovascular risk in psoriasis patients, and that only continuous long-term disease control may be helpful in reducing the cardiovascular risk associated with psoriasis.

Pulsatile Distension of the Proximal Aneurysm Neck is Larger in Patients with Stent Graft Migration

Purpose The proximal abdominal aortic aneurysm (AAA) neck expands significantly during the cardiac cycle, both before and after endovascular aneurysm repair (EVAR). Clinical consequences of this pulsatility were anticipated but have never been reported. This study investigated whether there is a relation between stent graft migration and preoperatively measured pulsatility of the proximal aneurysm neck. Methods EVAR patients with a preoperative dynamic computed tomography angiography (CTA), an immediate postoperative, and a CTA at 3 years after EVAR were included. The preoperative dynamic CTAs consisted of eight images per heartbeat. Aortic diameter and area changes per heartbeat were measured at two levels: (A) 3 cm above and (B) 1 cm below the most distal renal artery. Postoperatively, the distance between the most distal renal artery and the most proximal stent graft ring was measured. Two patient groups were distinguished according to whether migration during follow-up occurred (group 1) or had not occurred (group 2). The aneurysm neck dynamics of the two groups were compared by using the t-test for unpaired data and multivariable logistic regression analyses were performed. Mean values are presented with the standard deviation. Results Included were 26 patients (19 Talent, 6 Excluder and 1 Lifepath). Stent graft migration of ≥5 mm occurred in 11 patients (group 1). The pulsatility of the AAA neck in these patients was compared with the pulsatility in 15 patients with no graft migration (group 2). There were no significant differences in aortic neck characteristics (angulation, length and diameter) or degree of stent graft oversizing between the two groups. At level A in group 1 versus group 2, the diameter increase during the cardiac cycle was 2.0 ± 0.3 versus 1.7 ± 0.3 mm and the aortic area increase was 49 ± 15 versus 33 ± 12 mm 2. At level B in group 1 versus group 2, the diameter increase per heartbeat was 1.8 ± 0.3 versus 1.6 ± 0.4 mm, and the area increase was 37 ± 10 versus 25 ± 15 mm 2. The heartbeat-dependent diameter and area changes at both levels were significantly higher in group 1 compared with group 2. Multivariate regression analysis showed suprarenal aortic pulsatility was a significant predictor for stent graft migration after 3 years. Conclusion The preoperative heartbeat-dependent aneurysm neck distension is significantly associated with stent graft migration after 3 years. The aortic pulsatility in patients with stent graft migration is significantly higher than the pulsatility in patients without stent graft migration.

Aortic endograft sizing in trauma patients with hemodynamic instability

To investigate changes in aortic diameter in hemodynamically unstable trauma patients and the implications for sizing of thoracic endovascular aortic repair (TEVAR) in patients with traumatic thoracic aortic injury (TTAI). We retrospectively evaluated all trauma patients that were admitted with hemodynamic instability (mean arterial pressure <95 mm Hg and a pulse >or=100 beats/min) and underwent computed tomography (CT) of the thorax and abdomen both at admission and at another moment (control CT scan), at the Yale New Haven Hospital between 2002 and 2009. The CT examinations were reviewed in a blinded fashion and the aortic diameter was measured at six different levels by a cardiovascular radiologist. Differences in aortic diameter between the initial CTs obtained in the trauma bay and the control CTs were compared using the paired Student t test. Forty-three patients were identified, including 32 males. Mean age was 37 +/- 16 years, mean injury severity score was 26 +/- 15, the mean pulse and blood pressure were 122 beats/min and 103/63 mm Hg, respectively. Overall, the mean aortic diameter was significantly larger at the control CT examinations compared with the initial CT examinations while hemodynamically unstable, at all evaluated levels. Among patients with a pulse >or=130/min, the mean increase in aortic diameter was most consistent at the level of the mid descending thoracic aorta (DTA, +12.6%, P = .003) and at the level of the infrarenal aorta (+12.6%, P = .004). The aortic diameter decreases dramatically in trauma patients with hemodynamic instability. This decrease in aortic diameter could theoretically lead to inaccurate aortic measurements and undersizing of the endograft in hemodynamically unstable TTAI patients requiring TEVAR. Further research is needed to better predict the actual aortic diameters in individual hemodynamically unstable patients requiring endovascular aortic repair.

PS6. The Proximal Aneurysm Neck Distension in Patients With Stentgraft Migration Is Significantly Larger Than in Patients Without Migration

The proximal AAA neck expands significantly during the cardiac cycle, both before and after EVAR. Clinical consequences of this pulsatility are expected but never reported. The goal of this study is to investigate whether there is a relation between stentgraft migration and AAA neck distension. EVAR patients with a preoperative dynamic CTA, an immediate postoperative, and a CTA 3 years after EVAR were included. The preoperative dynamic CTAs consisted of 8 images per heartbeat. Aortic area and diameter changes per heartbeat were measured at 2 levels: (A) 3cm above and (B)1cm below the distal renal artery. Postoperatively, the distance between this renal artery and the most proximal stentgraft ring was measured. The pulsatility of patients with ≥5mm stentgraft migration after 3 years was compared to the pulsatility of patients without migration. All given values are mean. 26 patients were included (19 Talent, 6 Excluder, 1 Lifepath). 11 of them had stentgraft migration of ≥5mm (group 1). The pulsatility of the AAA neck in these patients was compared to the pulsatility in 15 patients with no graft migration (group 2). There were no significant differences in aortic neck characteristics (angulation, length, diameter) or degree of oversizing between the 2 groups. The diameter increase per heartbeat at level A in group 1 was 2.0 ± 0.3, and 1.7 ± 0.3mm in group 2. The aortic area increase was 49 ± 15 (group 1) and 33 ± 12 mm2 (group 2). The diameter increase per heartbeat at level B in group 1 was 1.8 ± 0.3, and 1.6 ± 0.4mm in group 2. The area increase at level B was 37 ± 10 (group 1) and 25 ± 15 mm2 (group 2). The heartbeat dependent diameter and area changes at both levels were significantly higher in patients of group 1 compared to those of patients in group 2 (all p < 0.05). The aortic distension is significantly higher in patients with stentgraft migration than in patients without stentgraft migration. Patients with higher aneurysm neck pulsatility are more prone to stentgraft migration.

Stentless aortic valve replacement in patients with bicuspid aortic valve disease: clinical outcome and aortic diameter changes during follow-up

A bicuspid aortic valve (BAV) may be associated with an aortopathy affecting clinical outcome. Our aim was to assess long-term outcome and analyse if progressive aortic dilatation occurs with time in patients with BAV disease who underwent stentless valve replacement. Demographic, operative and clinical data were retrospectively reviewed. Patients were classified according to whether their native aortic valve was identified as tricuspid (TC) or bicuspid (BC) at the time of AVR. Serial transthoracic echocardiography was used to measure changes in ascending aortic diameter over time. Propensity adjustment and multivariate regression were used. Events over time were assessed using the Kaplan-Meier method, and the determinants of events were assessed with the Cox proportional-hazards model. Between January 1991 and January 2001, 215 patients underwent AVR. They had a serial follow-up echocardiography performed for a mean of 6.1+/-4.3 years postoperatively. Ninety patients (41%) had a BAV, and the BC group was younger (BC 62+/-15 years vs TC 71+/-12 years; p=0.002). We found no difference in the increase in ascending aortic diameter over follow-up (BC 0.1+/-0.5 cm vs TC 0.0+/-0.5 cm; p=0.34). BC morphology was not an independent predictor of increased overall mortality (propensity-adjusted hazard ratio: 0.79; 95% confidence interval (CI): 0.42-1.44; p=0.44) or increased risk of reoperation (propensity adjusted hazard ration: 1.84; 95% CI: 0.88-3.36; p=0.11). Stentless AVR is protective against progressive aortic aneurysmal disease and confers excellent clinical outcomes in patients with BAV and normal preoperative ascending aortic diameter.

Impaired aortic stiffness and pulse wave velocity in patients with branch retinal vein occlusion

Aortic distensibility (AD) and pulse wave velocity (PWV) reflect arterial stiffness, which is linked to increased cardiovascular morbidity and mortality in different diseases such as atherosclerosis, hypertension, and diabetes mellitus, all of which are also common risk factors in patients with branch retinal vein occlusion (BRVO). In the present study, we aimed to determine whether arterial stiffness in different segments of the arterial tree is increased in patients with BRVO. The study group consisted of 35 patients with BRVO (20 female, 15 male, mean age: 55.9+/-6.8) and the age-matched control groups consisted of 19 patients with hypertension (9 female, 10 male, mean age: 55.2+/7.6) and 17 healthy subjects (9 female, 8 male, mean age: 53.4+/-9.6). Radial artery PWV was measured using a Pulse Wave Sensor HDI system, which measures non-invasively the radial pulse-wave recording with computer analysis of the diastolic decay, and provides separate assessment of the large arterial elasticity index (LAEI) and small artery elasticity index (SAEI). Aortic strain and AD was determined echocardiographically based on the relationship between changes in aortic diameter and pressure with each cardiac pulse. Patients with diabetes mellitus or inflammatory BRVO, and control patients with any occlusive vascular eye disease, were excluded. The results of the three groups were compared. Compared to the subjects of the healthy control group, those with BRVO had lower LAEI (p<0.05). Both AD and aortic strain were significantly lower in the BRVO group than in both control groups (p<0.05 for both) and in the hypertensive control group than the healthy controls (p<0.05). The AD, LAEI and SAEI were positively correlated (p=0.021, r=0.307 and p=0.041, r=0.269 respectively). The results of this study show that the arterial stiffness indices (large arterial elasticity index and aortic distensibility) are abnormal in patients with BRVO compared to the healthy and hypertensive controls. Arterial stiffness may play a role in the onset or progression of BRVO. Further studies are needed to determine the exact role of AS in the pathogenesis of BRVO, and to reveal its value in predicting systemic morbidity and mortality in patients with BRVO.

Losartan therapy in adults with Marfan syndrome: study protocol of the multi-center randomized controlled COMPARE trial

BackgroundMarfan syndrome (MFS) is one of the most common systemic disorders of connective tissue with the incidence of approximately 2-3 per 10 000 individuals. Aortic disease, leading to progressive aneurysmal dilatation and dissection is the main cause of morbidity and mortality of Marfan patients. Current treatment (e.g. beta blockers and elective surgery) does postpone but cannot prevent aortic complications in these patients. Recent studies have found Transforming Growth Factor β (TGF β) to be involved in the aortic aneurysm formation. Losartan, an Angiotensin II type 1 receptor blocker inhibits TGFβ in a mouse model of Marfan syndrome leading to inhibition of aortic growth. The main objective of this trial is to assess whether losartan treatment leads to a clinically relevant decrease of aortic dilatation in adult patients with Marfan syndrome.Methods/DesignCOMPARE study (COzaar in Marfan Patients Reduces aortic Enlargement) is an open-label, randomized, controlled trial with blinded end-points. Treatment with losartan will be compared with no additional treatment after 3 years of follow-up. We will enroll 330 patients with MFS who will be randomly assigned to receive losartan or not. Patients taking beta-blockers will continue taking their standard treatment. The primary end-point is the largest change in aortic diameter at any aortic level measured by means of MRI. Secondary end-points are change in mortality, incidence of dissection, elective aortic surgery, aortic volume, aortic stiffness and ventricular function. We will also investigate gene and protein expression change in the skin under losartan therapy and create prediction models for losartan-treatment response and aortic dilatation.DiscussionThe COMPARE study will provide important evidence of effects of losartan treatment in adult Marfan patient population. We expect losartan to significantly reduce the occurrence and progression of aortic dilatation. This trial investigates a wide spectrum of clinical, genetic and biochemical effects of losartan aiming to provide further insight in the pathogenesis and treatment of Marfan syndrome.Trial registrationNetherlands Trial Register NTR1423.

Comparison of volume and diameter measurement in assessing small abdominal aortic aneurysm expansion examined using computed tomographic angiography

Aim First we aimed to assess the reproducibility of a computer tomography angiography (CTA) based technique for measuring infra-renal aortic volume and diameter. Second we sought to investigate whether changes in aortic volume and diameter were similar during follow-up. Materials and methods A prospective series of 57 patients, with aortic diameter initially measuring between 25 and 55 mm, were assessed with 2 CTAs a median of 14 months apart. Aortic volume and maximum diameter (both axial and orthogonal) were measured by a semi-automated workstation protocol based on previously defined techniques. Intra- and inter-observer reproducibility were assessed by repeat assessment of the initial CTA images of the first 33 patients included in the study, in order to estimate the 95% limits of agreements. Changes in aortic dimensions between the first and follow-up CTA, were defined for volume and diameter separately as changes greater than their respective 95% limits of agreement. Results Reproducibility of aortic volume and diameter was excellent with an average coefficient of variation <4%. The median (inter-quartile range) increases in total volume, orthogonal and axial diameters were 4.9 cm 3 (0.01–14.18), 1.2 mm (0.40–3.50) and 1.4 mm (−0.15 to 3.55) respectively. Forty-two percent of patients who had increased aortic volume above the 95% limit of agreement did not display corresponding axial or orthogonal diameter changes. Conclusions Infra-renal total aortic volume, axial and orthogonal diameter can all be measured reproducibly from CTA. Aortic volume changes are not always reflected by similar changes in diameter and therefore provide complementary information when assessing AAA expansion over time.

Optimising the accuracy and reproducibility of aortic root measurements from cardiac MRI data

Methods An observational study of 20 consecutive children, (age 11, +/5.5 years) undergoing MRI for aortic root and arch assessment. None had undergone intervention. Imaging used standard true FISP cine sequences and an isotropic, respiratory-navigated, ECG-gated, 3D multi-slab SSFP sequence (allowing reformatting in any 3D-plane). A single, experienced observer measured the maximum diameter from cine images of the LV outflow tract (diastolic phase) and the 3D dataset (diastolic phase), at three aortic root levels and at the diaphragmatic aorta, twice, with one week between measurements. 3D data measurements used true cross-sectional planning, and included planimetered area. Aortic sinus diameter was measured from commissure-to-opposing-cusp (Figure 1). The difference between 2D cine and 3D diameters, and intra-observer variability were compared using Bland-Altman variability analysis Results Though measured in the same phase of the cardiac cycle, 2D cine diameters were smaller than 3D true-cross-sectional diameters (3.6-8.9%). There was no systematic variation with aortic size (Figure 2). The average intraobserver variability at sinus level for 3D data was 1% for diameter, and 5% for area. The variability for 2D cine measurements was 10%. In this best case scenario of repeated measurements, for paediatric aortic roots approximately 30 mm in diameter, a change in aortic sinus diameter would have to exceed 3 mm on 3D data and 6 mm on 2D cine data to be sure the change did not result from measurement variability (Table 1) from 13th Annual SCMR Scientific Sessions Phoenix, AZ, USA. 21-24 January 2010

Regional Age-Related Changes in Aortic Pulse Wave Velocity and Systolic Diameter Measured Using Magnetic Resonance Imaging

Regional Age-Related Changes in Aortic Pulse Wave Velocity and Systolic Diameter Measured Using Magnetic Resonance Imaging