Effect of age on aortic atherosclerosis

Objective To examine the association of atherosclerosis burden in the survivors of an asymptomatic elderly cohort study and its relationship to other coronary risk factors (specifically, age) by evaluating aortic atherosclerotic wall burden by magnetic resonance imaging (MRI). Methods A total of 312 participants in an ongoing observational cohort study underwent cardiac and descending thoracic aorta imaging by MRI. Maximum wall thickness was measured and the mean wall thickness calculated. Wall/outer wall ratio was used as a normalized wall index (NWI) adjusted for artery size difference among participants. Percent wall volume (PWV) was calculated as NWI × 100. Results In this asymptomatic cohort (mean age: 76 years), the mean (SD) aortic wall area and wall thickness were 222 ± 45 mm2 and 2.7 ± 0.4 mm, respectively. Maximum wall thickness was 3.4 ± 0.6 mm, and PWV was 32% ± 4%. Women appeared to have smaller wall area, but after correcting for their smaller artery size, had significantly higher PWV than men (P = 0.03). Older age was associated with larger wall area (P = 0.04 for trend) with similar PWVs. However, there were no statistically significant associations between standard risk factors, Framingham global risk, or metabolic syndrome status, therapy for cholesterol or hypertension, coronary or aortic calcium score, and the aortic wall burden. Aortic calcification was associated with coronary calcification. Conclusions Asymptomatic elderly in this cohort had a greater descending thoracic aortic wall volume that correlated with age, and women had a significantly increased PWV compared to men. In these survivors, the atherosclerotic aortic wall burden was not significantly associated with traditional risk factors or with coronary or aortic calcium scores or coronary calcium progression. Results suggest that age, or as yet unidentified risk factor(s), may be responsible for the increase in atherosclerosis.     

Relationship between plasma total antioxidant capacity and thoracic aortic intima-media thickness

It is known that antioxidants have an important role in the prevention of coronary artery disease (CAD). Low total antioxidant capacity (TAC) is a risk factor for ischemic heart disease. However, no data are available concerning the relationship between TAC and severity of thoracic aortic atherosclerosis. This study using multiplane transesophageal echocardiography (TEE) examined the relationship between atherosclerotic thoracic aortic intima-media thickness (TAIMT) and TAC. Twenty-nine patients (17 male, 12 female; mean age 36 +/- 8 years) without a history of atherosclerotic cardiovascular disease referred for TEE were included. The patients with obesity, hypertension, diabetes, and CAD were excluded. The TAC was measured for each patient using a more recently developed method. TAIMT and grade of thoracic aortic atherosclerosis were evaluated in each patient by using TEE. Mean TAC level was 1.91 +/- 0.53 mmol Trolox equiv/l. There was a negative and significant correlation between the TAC levels and TAIMT and grade of thoracic aortic atherosclerosis (r = -0.799, P < 0.001 versus r = -0.827, P < 0.001, respectively). Multiple linear regression analysis showed that TAIMT was independently associated with TAC (beta = -0.734, P < 0.001). The mean values of TAC in grade I, II, and III were 2.23 +/- 0.31, 1.58 +/- 0.31, and 1.04 +/- 0.27 mmol Trolox equiv/l, respectively (ANOVA P < 0.001). This study indicates that the TAC is an independent variable for TAIMT and it has a potential for an independent variable for atherosclerotic lesions in the major arterial locations.     

Relationship of hypertensive retinopathy to thoracic aortic atherosclerosis in patients with severe arterial hypertension

Arterial hypertension complicated with atherosclerosis presents the most common cause of death in hypertensive patients. Eyes suffer vascular damage as a result of high blood pressure (BP) and these changes can be detected by funduscopy, although its role has recently been questioned. The aims of this study were to assess the prevalence of atherosclerotic plaques and other disorders of thoracic aorta by transesophageal echocardiography (TEE) in patients with severe arterial hypertension of at least 1 year duration and to analyze the association between aortic atherosclerotic plaques and hypertensive retinopathy. This was a prospective TEE study conducted on 56 hypertensive patients from September 2008 to January 2010. Mean patient age was 62.8 ± 8.2 years and 67.86% of them were women. Aortic atherosclerotic plaques were found on 96.4% of patients, whereas hypertensive retinopathy was present on 94.6% of them. The mean thickness of maximal atherosclerotic plaque found on each patient was 4.3 ± 1.9 mm and 28.6% of patients had ulcerative plaques, while descending aorta was the most common location of the lesions. Grade 1 and 2 hypertensive retinopathy was diagnosed in 14.3% and 80.3% of patients, respectively. Hypertensive retinopathy correlated highly with aortic atherosclerotic score (r = 0.76, p < 0.0001), as it correlated significantly with aortic plaque thickness (r = 0.69, p < 0.0001). Application of funduscopy should be encouraged since it is a noninvasive procedure that provides a good window of retinal arterioles. Hypertensive retinopathy, even in mild forms, should serve as a marker of atherosclerosis elsewhere in the organism.     

Quantification of Atherosclerotic Burden in the Descending Aorta by Transesophageal Echocardiography: Inter- and Intraobserver Variability

Atherosclerotic plaques had been imaged but not quantitated in the thoracic aorta using transesophageal echocardiography. The aim of this study was to describe a method for measuring the atherosclerotic plaque area in the descending aorta by transesophageal echocardiography (TEE) and to evaluate its reproducibility. TEE examinations were performed by two independent sonographers, in 21 patients with angiographically proven coronary artery disease. Two hundred fifty-six transverse segments (mean 12 ± 3 patient) of the descending aorta were adequately recorded. In each segment the plaque and the lumen areas in the half of the aortic segment distant from the transesophageal probe were measured by one reader in the two studies (intersonographer reproducibility). Interreader reproducibility was also evaluated. The correlation coefficient between the first and second study (intersonographer reproducibility) was 0.81. The standard deviation of the difference between examinations equaled 0.137 cm² and the mean absolute difference between examinations was 0.003 cm² (95% CI: –0.015; 0.021; P = 0.75). The correlation coefficient between the two readers was 0.86, the standard deviation of the difference between readers was 0.175 cm² and the mean absolute difference was 0.006 cm² (95% CI: –0.029; 0.018; P = 0.63). A method for quantitative measurement of aortic atherosclerotic plaque area was evaluated and found to have high intersonographer and intereader reproducibilities. This method might be used in the future for noninvasive evaluation of regression or progression of aortic atherosclerosis.     

小鼠腹主动脉斑块模型建立的两种方法及超高场强磁共振成像的应用价值

目的 探讨建立腹主动脉粥样硬化斑块模型的方法及超高场强磁共振成像(MRI)在活体监测及量化小鼠腹主动脉粥样硬化斑块中的应用价值.方法 高脂饮食法小鼠腹主动脉粥样硬化斑块模型的建立及磁共振检测(高脂饮食组):选择3批10～12月龄apoE-/-小鼠13只、WT鼠3只高脂饮食喂养,分别于喂养前、喂养3个月、喂养6个月3个时期进行小鼠腹主动脉7.0 T磁共振活体扫描.血管紧张素Ⅱ(AngⅡ)灌注法小鼠腹主动脉粥样硬化斑块模型的建立及磁共振检测(AngⅡ灌注组):选用10只6月龄apoE-/-小鼠,分为AngⅡ1000 ng·kg-1·min-1组3只、AngⅡ500 ng·kg-1·min-1组3只(以上两组均在背部埋置AngⅡ缓释泵14 d)和对照组为4只(埋置生理盐水缓释泵),分别于灌注前后行磁共振扫描,选用FLASH T1WI黑血及MSME-T2WI-PDWI双回波序列.高脂饮食组依次在各时期扫描后分别处死3、5、5只小鼠,AngⅡ灌注组于装泵后14 d行磁共振扫描,然后处死本组小鼠,取处死小鼠的肾动脉段腹主动脉制作病理切片,进行苏木素-伊红(HE)染色、Masson胶原纤维(CME)染色.每只小鼠选5～7层肾动脉段腹主动脉病理图像及多对比MRI图像,分别测量外腔面积(VOA)、内腔面积(LA),计算管肇面积(VWA)并进行MRI与病理测量结果的相关性分析.结果 两种方法建立的小鼠模型,其腹主动脉MRI与病理切片均可见不稳定斑块形成.高脂饮食组随着高脂饮食时间的延长,斑块进展,VWA不断增加,3个时期VWA方差分析F=29.94(P<0.05),斑块信号于PDWI、T2WI逐渐增加,且不均匀.高脂饮食组MRI测量的斑块面积与病理测量的斑块面积有较高的-致性(高脂喂养前、喂养3和6个月3个时期r值分别为0.84、0.95、0.90).病理切片中斑块成分与磁共振显示信号一致,均表现为脂质成分增加,纤维成分减少.AngⅡ1000 ng·kg-1·min-1组AngⅡ灌注后斑块面积与灌注前比较差异有统计学意义(P=0.017),分别为(2.65±0.48)mm2和(1.21±0.21)mm2,部分小鼠可见夹层动脉瘤形成.AngⅡ500 ng·kg-1·min-1组灌注后斑块面积也比灌注前有所进展,面积分别为(1.01±0.17)mm2和(0.85±0.11)mm2,MRI测量的斑块面积与病理测量的斑块面积有较高的一致性(r值为0.93).结论 AngⅡ灌注显著加快动脉粥样硬化进展并促进腹主动脉夹层动脉瘤形成,长期高脂饮食亦可形成晚期斑块.超高场强MRI多种序列黑血技术的综合应用能显示小鼠腹主动脉粥样硬化斑块的进展,其检测分析斑块大小结果与病理表现基本一致,对斑块成分的判定亦有一定价值.     

Comparison of conventional and transesophageal echocardiography with magnetic resonance imaging for anatomical mapping of thoracic aortic dissection

Thirty-five consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol using comprehensive echocardiography and ECG-triggered MRI with multi-slice spin echo and cine sequences in random order. The purpose of this dual imaging study was to compare the diagnostic accuracy of two-dimensional and color-coded Doppler echocardiography using the conventional transthoracic (TTE) and the transesophageal approach (TEE) with magnetic resonance imaging (MRI) for the exact morphologic evaluation and anatomical mapping of the thoracic aorta. The results of each diagnostic method were validated independently against the gold standard of intraoperative findings (n=17), necropsy (n=4) or contrast angiography (n=22).Compared to conventional transthoracic echocardiography both TEE and MRI were more reliable in detecting aortic dissections (TTE vs TEE: p<0.02; TTE vs MRI: p<0.01) and associated epiphenomena. Moreover, the reliability of TTE decreased significantly from proximal to distal segments of the aorta, e.g. from the ascending segment to the arch (p<0.05) and to the descending aorta (p<0.005), whereas the sensitivities of both TEE and MRI were excellent irrespective of the site of dissection. With regard to epiphenomena such as thrombus formation and entry location, MRI emerged as the optimal method for detailed morphologic information in all segments of the aorta. No serious side effects were encountered with either method.Thus, in patients with suspected acute or subacute aortic dissections the echocardiographic assessment should include the transesophageal approach for significant improvement of the moderate sensitivity and specificity of TTE. Both TEE and MRI are non-traumatic, safe and diagnostically accurate to identify and classify acute and subacute dissections of the thoracic aorta irrespective of their location. MRI provides superb anatomical mapping of all type A and B dissections and more detailed information on the site of entry and thrombus formation than TEE. These features of TEE and MRI may render retrograde contrast angiography obsolete in the setting of thoracic aortic dissection and may encourage surgical interventions exclusively on the basis of noninvasive imaging.     

Diagnosis of thoracic aortic dissection. Magnetic resonance imaging versus transesophageal echocardiography.

BACKGROUND. Aortic dissection requires prompt and reliable diagnosis to reduce the high mortality. The purpose of this study was to assess the reliability of both ECG-triggered magnetic resonance imaging (MRI) and transesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) for the diagnosis of thoracic aortic dissection and associated epiphenomena. METHODS AND RESULTS. Fifty-three consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol in random order; imaging results were compared and validated against the independent morphological "gold standard" of intraoperative findings (n = 27), necropsy (n = 7), and/or contrast angiography (n = 53). No serious side effects were encountered with either imaging method. In contrast to a precursory screening transthoracic echogram, the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta irrespective of its location. The specificity of TEE, however, was lower than the specificity of MRI for a dissection (TEE, 68.2% versus MRI, 100%; p less than 0.005), which resulted mainly from false-positive TEE findings confined to the ascending segment of the aorta (TEE, 78.8% versus MRI, 100%; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation, or pericardial effusion. CONCLUSIONS. Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. TEE, however, is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE as a semi-invasive diagnostic procedure after a precursory screening transthoracic echogram in suspected aortic dissection, but they establish MRI as an excellent method to avoid false-positive findings. Anatomic mapping by MRI may emerge as the most comprehensive approach and morphological standard to guide surgical interventions.     

Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis

BACKGROUND: Patients with suspected thoracic aortic dissection require early and accurate diagnosis. Aortography has been replaced by less invasive imaging techniques including transesophageal echocardiography (TEE), helical computed tomography (CT), and magnetic resonance imaging (MRI); however, accuracies have varied from trial to trial, and which imaging technique should be applied to which risk population remains unclear. We systematically reviewed the diagnostic accuracy of these imaging techniques in patients with suspected thoracic aortic dissection. METHODS: Published English-language reports on the diagnosis of thoracic aortic dissection by TEE, helical CT, or MRI were identified from electronic databases. Sensitivity, specificity, and positive and negative likelihood ratios were pooled in a random-effects model. RESULTS: Sixteen studies involving a total of 1139 patients were selected. Pooled sensitivity (98%-100%) and specificity (95%-98%) were comparable between imaging techniques. The pooled positive likelihood ratio appeared to be higher for MRI (positive likelihood ratio, 25.3; 95% confidence interval, 11.1-57.1) than for TEE (14.1; 6.0-33.2) or helical CT (13.9; 4.2-46.0). If a patient had shown a 50% pretest probability of thoracic aortic dissection (high risk), he or she had a 93% to 96% posttest probability of thoracic aortic dissection following a positive result of each imaging test. If a patient had a 5% pretest probability of thoracic aortic dissection (low risk), he or she had a 0.1% to 0.3% posttest probability of thoracic aortic dissection following a negative result of each imaging test. CONCLUSION: All 3 imaging techniques, ie, TEE, helical CT, and MRI, yield clinically equally reliable diagnostic values for confirming or ruling out thoracic aortic dissection.     

Comparison of magnetic resonance imaging of aortic valve stenosis and aortic root to multimodality imaging for selection of transcatheter aortic valve implantation candidates

The purpose of the present study was to compare the aortic valve area, aortic valve annulus, and aortic root dimensions measured using magnetic resonance imaging (MRI) with catheterization, transthoracic echocardiography (TTE), and transesophageal echocardiography (TEE). An optimal prosthesis--aortic root match is an essential goal when evaluating patients for transcatheter aortic valve implantation. Comparisons between MRI and the other imaging techniques are rare and need validation. In 24 consecutive, high-risk, symptomatic patients with severe aortic stenosis, aortic valve area was prospectively determined using MRI and direct planimetry using three-dimensional TTE and calculated by catheterization using the Gorlin equation and by Doppler echocardiography using the continuity equation. Aortic valve annulus and the aortic root dimensions were prospectively measured using MRI, 2-dimensional TTE, and invasive aortography. In addition, aortic valve annulus was measured using TEE. No differences in aortic valve area were found among MRI, Doppler echocardiography, and 3-dimensional TTE compared with catheterization (p = NS). Invasive angiography underestimated aortic valve annulus compared with MRI (p <0.001), TEE (p <0.001), and 2-dimensional TTE (p <0.001). Two-dimensional TTE tended to underestimate the aortic valve annulus diameters compared to TEE and MRI. In contrast to 2-dimensional TTE, 3 patients had aortic valve annulus beyond the transcatheter aortic valve implantation range using TEE and MRI. In conclusion, MRI planimetry, Doppler, and 3-dimensional TTE provided an accurate estimate of the aortic valve area compared to catheterization. MRI and TEE provided similar and essential assessment of the aortic valve annulus dimensions, especially at the limits of the transcatheter aortic valve implantation range.     

Interrelation between the extent of atherosclerosis in the thoracic aorta, carotid intima-media thickness and the extent of coronary artery disease

Intima-media thickness (IMT) of the common carotid artery and atherosclerosis of the thoracic aorta have been shown to correlate with coronary artery disease (CAD). This study compares the relation between wall changes in the thoracic aorta and the carotid arteries and the angiographic severity and extent of atherosclerotic lesions in the coronary arteries in patients with verified CAD. Atherosclerotic wall changes in the carotid arteries and the thoracic aorta were measured by B-mode ultrasonography and transesophageal echocardiography (TEE), respectively, in 37 subjects aged 65+/-10 years with angiographically verified CAD. The mean value of the common carotid IMT of the right and left sides was 0.87+/-0.21 mm. All subjects had carotid plaques. TEE detected grades II-IV atherosclerotic plaques in the thoracic aorta in 32 of the 37 (86%) patients. A significant correlation was seen between the extent of coronary artery stenosis and aortic plaques score (r=0.46, p=0.008). Mean carotid IMT was also significantly correlated with coronary artery stenosis extent score (r=0.44, p=0.007). Moreover, a significant correlation was seen between the aortic plaque score and the mean carotid IMT (r=0.39, p=0.02). In conclusion, we found a clear and significant relationship between wall changes in the thoracic aorta, common carotid IMT and the angiographic extent of coronary artery stenosis in patients with severe CAD. These findings indicate a potential of B-mode ultrasonography of the carotid arteries and transesophageal echocardiographic aortic examination in the diagnostic and prognostic evaluation of patients with suspected CAD.     

Relation between the incidence, location, and extent of thoracic aortic atherosclerosis detected by transesophageal echocardiography and the extent of coronary artery disease by angiography

Atherosclerotic lesions in the thoracic aorta detected by transesophageal echocardiography (TEE) have been correlated with coronary artery disease (CAD). We determined whether simple or complex aortic plaques seen on transesophageal echocardiogram correlated with extent, location, and severity of CAD. The study population consisted of 188 patients who underwent TEE and coronary angiography. Atherosclerotic plaques seen on transesophageal echocardiogram were defined as (1) complex plaques in the presence of protruding atheroma ≥4-mm thickness, mobile debris, or plaque ulceration or (2) simple plaques in the absence of findings consistent with complex plaques. Extent of CAD was grouped into 4 groups according to number of coronary vessels with ≥70% stenosis. Numbers of patients with CAD with 0-, 1-, 2-, and 3-vessel disease were 99, 31, 28, and 30 respectively. Compared to patients without CAD, patients with CAD (n = 89) had a significantly greater prevalence of aortic atherosclerotic plaques irrespective of degree of plaque complexity or location (p <0.05). Multivariate analysis found that hypertension (odds ratio 3.0, 95% confidence interval 1.3 to 7.0, p = 0.013), diabetes mellitus (odds ratio 2.4, 95% confidence interval 1.1 to 4.9, p = 0.022), and aortic plaque (odds ratio 3.8, 95% confidence interval 1.8 to 8.2, p = 0.001) were significantly associated with CAD. There was a significant relation between simple and complex aortic plaques with increasing severity of CAD (p <0.001). Multivariate logistic regression analysis showed that complex plaque in the descending aorta (odds ratio 5.4, 95% confidence interval 1.8 to 16.4, p = 0.003) was the strongest predictor of CAD. In conclusion, simple and complex thoracic atherosclerotic plaques detected by TEE are associated with increasing severity of CAD. Complex plaque in the descending aorta was the strongest association with presence of CAD.     

Assessment of atherosclerotic lesions and distensibility of the thoracic aorta in familial hypercholesterolemia by biplane transesophageal echocardiography]

Atherosclerosis involving the thoracic aorta frequently occurs in patients with familial hypercholesterolemia (FH). In this study, we employed two-dimensional (2-D) transesophageal echocardiography (TEE: 5 MHz) to assess atherosclerotic lesions of the thoracic aorta in 9 patients with FH (47.8 +/- 10.3 yrs) and 11 age-matched normal control subjects. Biplane TEE probe (i.e., transverse or sagittal scan transducer) was used to permit direct imaging of the distal half of the ascending aorta. The atherosclerotic lesions were classified based on the severity of the aortic wall sclerosis as intimal thickening (I.), atheromatous plaque, (II.) and calcification (III.). In all of the patients with FH, atherosclerotic lesions of grade I. or greater were observed particularly in the aortic arch and descending aorta, while, lesions more severe than grade I. in the thoracic aorta were not observed in any of the control subjects. In 6 FH patients (67%), atherosclerotic lesions more severe than grade II. were frequently observed, which were more frequent in the aortic arch and descending aorta than in the ascending aorta.     

Penetrating atherosclerotic aortic ulcer: documentation by transesophageal echocardiography

Objectives. This study sought to describe the ability of transesophageal echocardiography (TEE) to document the presence of penetrating atherosclerotic aortic ulcers and their complications.Background. TEE has greatly enhanced our ability to assess patients with suspected aortic disease. However, the utility of this technique in the diagnosis of penetrating atherosclerotic aortic ulcers is still undefined.Methods. TEE was performed prospectively in 194 patients to evaluate aortic disease. Twelve patients with the diagnosis of aortic ulcers or their complications were specifically studied. The diagnosis was confirmed by pathologic studies in six patients and by an additional diagnostic technique (angiography, computed tomography or magnetic resonance imaging) in the other six. All 12 patients were hypertensive and presented with chest or back pain; the mean age was 65 years (range 56 to 79). The initial working diagnosis was acute aortic dissection in nine patients. Aortic ulcers were located in the descending thoracic aorta in eight patients, the aortic arch in two and the ascending aorta in two.Results. TEE could detect aortic ulcers or their complications in 10 patients but failed to detect these lesions in the remaining 2 (1 with aortic ulcers in the distal ascending aorta and 1 with aortic ulcers in the aortic arch). In four patients, aortic ulcers were detected as a calcified focal outpouching of the aortic wall and were associated with concomitant aneurysmal dilation of the aorta in two patients and with a small localized intramural hematoma in one. TEE visualized a partially thrombosed pseudoaneurysm complicating an aortic ulcer in the descending thoracic aorta of two patients. Four patients had an aortic ulcer complicated by a “limited aortic dissection” in the descending aorta that could be detected by TEE. Five patients underwent operation, two because of aneurysmal dilation of the aorta and three because of aortic dissection; two patients died of aortic rupture; the remaining five did well (11-month follow-up) without operation.Conclusions. Aortic ulcers should be included in the differential diagnosis of chest or back pain, especially in elderly hypertensive patients. These ulcers and their complications may be recognized by TEE.     

Elevated serum lipoprotein(a) level is an independent marker of severity of thoracic aortic atherosclerosis

STUDY OBJECTIVE: Lipoprotein(a) (Lp[a]) level is a risk factor for ischemic heart disease, cerebrovascular disease, and peripheral vascular disease. However, few data are available concerning the relationship between Lp(a) level and severity of thoracic aortic atherosclerosis. We hypothesized in this transesophageal echocardiography (TEE) study that Lp(a) level is a marker of severity of thoracic aortic atherosclerosis. DESIGN: Cross-sectional study. SETTING: University hospital. PATIENTS: Risk factors, coronary angiographic features, and TEE findings were analyzed prospectively in 119 patients with valvular disease. MEASUREMENTS AND RESULTS: The following risk factors were recorded: age, gender, hypertension, smoking, lipid parameters, diabetes, body mass index, and family history of coronary artery disease. Serum levels of Lp(a) were measured for each patient. By univariate analysis, age, diabetes, hypertension, smoking, Lp(a), total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were significant predictors of thoracic aortic atherosclerosis. There was a positive and significant correlation between the Lp(a) levels and the score of severity of thoracic aortic atherosclerosis (p = 0.0001). Multivariate regression analysis revealed that Lp(a) was an independent predictor of severity of thoracic aortic atherosclerosis (p = 0.0001). CONCLUSION: This prospective study indicates that serum Lp(a) level is an independent marker of severity of thoracic aortic atherosclerosis detected by multiplane TEE. These findings emphasize the role of Lp(a) as a marker of atherosclerotic lesions in the major arterial locations.     

Atherosclerosis of the aorta in patients with acute thoracic aortic dissection

BACKGROUND: The role of atherosclerosis in thoracic aortic dissection has not been established yet. Transesophageal echocardiography (TEE) is an imaging modality widely used in the diagnostic evaluation of thoracic aortic dissection, and it can detect aortic atherosclerotic plaques and assess their size and specific characteristics. METHODS AND RESULTS: One hundred consecutive patients with thoracic aortic dissection and adequate imaging of the thoracic aorta by TEE were studied. The type of dissection (proximal or distal) and the presence and the degree of aortic atherosclerosis were defined. Proximal aortic dissection (Stanford type A) was found in 64 patients. Patients with proximal dissection were younger than those with distal (type B; 58+/-13 vs 67+/-11 years, p<0.001). The prevalence of arterial hypertension was higher in patients with distal dissection compared with those with proximal. Aortic atherosclerosis was present in less patients with proximal than with distal dissection (67% vs 94%, p<0.002). Logistic regression analysis revealed that patients with severe atherosclerosis were 7.6-fold more probable to have type B than type A dissection (p<0.001). CONCLUSION: Aortic atherosclerosis is more associated with distal than with proximal aortic dissection.     

Atherosclerotic aortic component quantification by noninvasive magnetic resonance imaging: an in vivo study in rabbits

OBJECTIVES: We sought to demonstrate the ability that noninvasive in vivo magnetic resonance imaging (MRI) has to quantify the different components within atherosclerotic plaque. BACKGROUND: Atherosclerotic plaque composition plays a critical role in both lesion stability and subsequent thrombogenicity. Noninvasive MRI is a promising tool for the characterization of plaque composition. METHOD: Thoracic and abdominal aortic atherosclerotic lesions were induced in rabbits (n = 5). Nine months later, MRI was performed in a 1.5T system. Fast spin-echo sequences (proton density-weighted and T2-weighted [T2W] images) were obtained (in-plane resolution: 350 x 350 microns, slice thickness: 3 mm). Magnetic resonance images were correlated with matched histopathological sections (n = 108). RESULTS: A significant correlation (p < 0.001) was observed for mean wall thickness and vessel wall area between MRI and histopathology (r = 0.87 and r = 0.85, respectively). The correlation was also present on subanalysis of the thoracic and upper part of the abdominal aorta, susceptible to respiratory motion artifacts. There was a significant correlation for plaque composition (p < 0.05) between MRI and histopathology for the analysis of lipidic (low signal on T2W, r = 0.81) and fibrous (high signal on T2W, r = 0.86) areas with Oil Red O staining. T2-weighted images showed greater contrast than proton density-weighted between these different components of the plaques as assessed by signal intensity ratio analysis with the mean difference in signal ratios of 0.47 (S.E. 0.012, adjusted for clustering of observations within lesions) being significantly different from 0 (t1 = 39.1, p = 0.016). CONCLUSIONS: In vivo noninvasive high resolution MRI accurately quantifies fibrotic and lipidic components of atherosclerosis in this model. This may permit the serial analysis of therapeutic strategies on atherosclerotic plaque stabilization.     

Correlation between aortic atherosclerosis at transesophageal echocardiography and coronary atherosclerosis

The aim of this study was to test the relationship between atherosclerotic plaques in the thoracic aorta detected by transesophageal echocardiography and coronary artery disease detected by angiography. A prospective study was carried out in 103 patients who underwent coronary angiography. All patients underwent transesophageal echocardiography with imaging of the thoracic aorta. Aortic intimal changes were classified in 4 grades. The detection of aortic atheroma plaques was the strongest predictor of coronary artery disease. The presence of aortic plaques on transesophageal study had a sensitivity of 97.6% and a specificity of 80% for angiographically proved obstructive coronary artery disease. The positive predictive value of aortic plaque for obstructive coronary artery disease was 95.3% and the negative predictive value was 88.9%. Compared to the other segments, the detection of atherosclerotic plaque in the descending aorta has the highest sensitivity but the specificity was the highest in the ascending aorta. With older age and in women the specificity decreased, while the sensitivity increased.     

Role of echocardiography in aortic atherosclerotic disease and stroke

Patients with severe aortic atherosclerosis are at high risk for stroke. The risk is highest for those with atherosclerotic plaque measuring = or >4 mm in thickness. There is currently no proven medical therapy to reduce embolic risk in patients with aortic plaque. Antiplatelet therapy, smoking cessation, and management of diabetes and hypertension are important. Retrospective data support the use of statins to prevent stroke in patients with severe aortic plaque. Embolism from aortic atherosclerosis may occur spontaneously, or less commonly, as a complication of invasive or surgical cardiovascular procedures. Transesophageal echocardiography (TEE) is the procedure of choice for the characterization of plaque and the detection of superimposed mobile thrombi. Therefore, TEE is a useful tool to identify patients at high risk for stroke. For patients who are being evaluated for coronary artery bypass graft (CABG) surgery or coronary angiography, the risks and benefits of these procedures must be carefully weighed and alternate approaches should be considered in patients with severe plaque. Options include off-pump CABG or coronary angiography via a brachial (rather than femoral) approach.     

胸主动脉病变术中应用经食管超声心动图的初步探讨

目的：探讨胸主动脉疾病的术中应用经食管超声心动图（ＴＥＥ）的价值及适应证。方法：本文报道８例（１５～６３岁，平均年龄４４．５岁）不同类型胸主动脉疾病术中ＴＥＥ监测结果。病例包括先天性主动脉瓣上狭窄、升主动脉瘤、主动脉夹层及主动脉夹层伴假性动脉瘤、胸降主动脉假性动脉瘤、主动脉瓣脱垂等。结果：８例患者的术中检查与术前诊断全部吻合。术中ＴＥＥ发现１例主动脉夹层累及左锁骨下动脉，而术前磁共振成像未能提示。此外，术中ＴＥＥ还显示２例胸降主动脉内的粥样硬化斑块。结论：初步显示术中ＴＥＥ可即刻评价手术效果，对拟行主动脉瓣成形术的患者最有价值；为避免升主动脉粥样斑块的脱落导致术后体循环尤其是脑栓塞，对于高龄患者也积极提倡术中ＴＥＥ监测。     

Missed diagnosis of limited ascending aortic dissection by multiple imaging modalities leading to fatal cardiac tamponade and aortic rupture

Modern diagnostic imaging modalities for ascending aortic dissection include transesophageal echocardiography (TEE), computed tomography angiography (CTA), and magnetic imaging resonance (MRI). All have extremely high sensitivity and specificity for detection of an intimal flap to diagnose ascending aortic dissection. We present a case of fatal cardiac tamponade caused by a limited aortic dissection not detected by multiple imaging modalities. This may represent a class of aortic dissection variant that cannot be detected by conventional testing. A high index of suspicion should be maintained in the appropriate clinical setting and should prompt serial imaging and even consideration for preemptive surgical exploration.