Embolism from the aorta: Atheroemboli and thromboemboli

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Relationship between aortic valve calcification and aortic atherosclerosis: a transoesophageal echocardiography study

INTRODUCTION: Clinical and laboratory data provide an increasing amount of information regarding the common aetiopathogenetic background of acquired heart defects with calcification and arterial atherosclerosis. AIM: To evaluate the relationship between presence and severity of calcifications of the aortic semilunar valves and the intensity of atherosclerotic lesions in the aorta and aortic stiffness (AS). METHODS: The study group comprised 80 subjects (49 males and 31 females) aged 72.2 (+/-8.0) years with an aortic valve defect found on echocardiography. Patients were divided into two subgroups depending on the severity of valvular disease. Subgroup I comprised 42 patients with small valvular lesions (0--absence of calcification of the valve, or +--trivial valvular calcifications, possible to find on detailed evaluation of the valve). Subgroup II consisted of 38 patients with intense calcifications (++--large, easily found valve calcifications, +++--massive calcifications affecting leaflet mobility). All patients underwent transoesophageal echocardiography to evaluate atherosclerotic lesions in the aorta. The assessment included the following: location of the lesions in the aorta, intimal thickness, presence of calcifications and mobile parts of plaques and possible associated thrombi. Aortic stiffness was also measured using the formula: AS=log (SBP/DBP)/Ao(max)-Ao(min)/Ao(min). RESULTS: Atherosclerotic plaques were more frequent in patients with more prominent calcifications of the aortic valve (19 vs 10 patients, p <0.05). Intimal thickness was larger in patients with more pronounced valve calcifications (3.9+/-0.8 mm vs 2.2+0.6 mm, p <0.05). Presence of calcifications in the aortic wall was also more frequent in patients from group II, as they were found in 10 subjects compared to only 3 cases in group I. Mobile plaque parts were observed in 3 patients from group II; also thrombi were found in 3 individuals from this group. Patients with more prominent calcifications of the aortic valve had decreased aortic wall elasticity (AS 5.5+/-1.2 cm vs 3.4+/-0.9 cm, p <0.05). CONCLUSIONS: Severity of aortic valve calcification indicates simultaneous changes in the thoracic aorta. Stiffness of the aortic wall is greater in patients with a more pronounced defect of the aortic valve. Prevalence of atherosclerosis risk factors is increased in patients with aortic valve defect, enhanced atherosclerosis and rigidity of the aorta. Defect of the aortic valve and increased aortic rigidity may be different manifestations of atherosclerosis.     

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.     

Assessment of aortic atherosclerosis and carotid atherosclerosis in coronary artery disease

The present study investigated the relationship between aortic atherosclerosis and carotid atherosclerosis, and studied the effects of coronary risk factors for these arteries. The subjects consisted of 78 patients with coronary artery disease (CAD) and 69 patients without CAD. All subjects underwent enhanced computed tomography and B-mode ultrasonography within a short time period to determine the extent of aorta and carotid atherosclerosis. Significant correlations between maximal aortic wall thickness (MAWT) and aortic wall volume (AWV) with carotid intima-media thickness (IMT) were demonstrated. MAWT, AWV and IMT were significantly higher in patients with CAD compared with controls (p=0.009, p=0.024, p=0.001, respectively). Furthermore, there were significant differences in MAWT, AWV and IMT among groups classified by the number of coronary artery stenoses, and no significant differences among groups classified by risk factors, but it was shown that MAWT, AWV and IMT increased gradually as the risk factors increased in number. MAWT, AWV and IMT had positive correlations with age, systolic blood pressure and triglyceride, and a negative correlation with high density lipoprotein-cholesterol. This study demonstrated that both aortic atherosclerosis and carotid atherosclerosis are closely correlated with coronary atherosclerosis, and that the atherosclerosis indices are independently associated with age and hyperlipidemia.     

经导管主动脉瓣置换的并发症

自2002年进行了世界上首例经导管主动脉瓣膜置换(transcatheter aortic valve implant,TAVI)治疗主动脉狭窄,世界各地的研究均表明:对于无法进行外科主动脉瓣膜置换(aortic valve replacement,AVR)或外科AVR手术存在高风险的患者,这项新技术是安全有效的。尽管进行TAVI手术的多为高风险患者,但手术成功后30 d生存率高于90%,     

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.     

Angiopoietins,abdominal aortic aneurysm and atherosclerosis

Abdominal aortic aneurysm (AAA) and atherosclerosis are common causes of mortality and morbidity in an aging population. Angiogenesis is believed to contribute to the development and progression of these diseases. Angiopoietins (angpts) are known to be important regulators of angiogenesis. Angpts can also influence inflammation and have been shown to possess both pro-atherosclerotic and atheroprotective effects. This review explores the potential roles that the angpts play in the development and progression of AAA and atherosclerosis.     

Abdominal aortic calcium and multi-site atherosclerosis: the Multiethnic Study of Atherosclerosis

BackgroundAbdominal aortic calcification (AAC) is a measure of subclinical cardiovascular disease (CVD). Data are limited regarding its relation to other measures of atherosclerosis.MethodsAmong 1812 subjects (49% female, 21% black, 14% Chinese, and 25% Hispanic) within the population-based Multiethnic Study of Atherosclerosis, we examined the cross-sectional relation of AAC with coronary artery calcium (CAC), ankle brachial index (ABI), and carotid intimal medial thickness (CIMT), as well as multiple measures of subclinical CVD.ResultsAAC prevalence ranged from 34% in those aged 45–54 to 94% in those aged 75–84 (p < 0.0001), was highest in Caucasians (79%) and lowest in blacks (62%) (p < 0.0001). CAC prevalence, mean maximum CIMT ≥ 1 mm, and ABI < 0.9 was greater in those with vs. without AAC: CAC 60% vs. 16%, CIMT 38% vs. 7%, and ABI 5% vs. 1% for women and CAC 80% vs. 37%, CIMT 43% vs. 16%, and ABI 4% vs. 2% for men (p < 0.01 for all except p < 0.05 for ABI in men). The substantially greater prevalence for CAC in men compared to women all ages is not seen for AAC. By age 65, 97% of men and 91% of women have AAC, CAC, increased CIMT, and/or low ABI. The presence of multi-site atherosclerosis (≥3 of the above) ranged from 20% in women to 30% in men (p < 0.001), was highest in Caucasians (28%) and lowest in Chinese (16%) and ranged from 5% in those aged 45–54 to 53% in those aged 75–84 (p < 0.01 to p < 0.001). Finally, increased AAC was associated with 2–3-old relative risks for the presence of increased CIMT, low ABI, or CAC.ConclusionsAAC is associated with an increased likelihood of other vascular atherosclerosis. Its additive prognostic value to these other measures is of further interest.     

Relationship between inhibition of aortic histamine formation, aortic albumin permeability and atherosclerosis

Effects of partial inhibition of aortic histamine formation on aortic albumin uptake and lipid deposition were examined in male, New Zealand white rabbits maintained on Purina Rabbit Chow containing 0.5% cholesterol for a 2-week period. Aortic histamine synthesis was inhibited by partial inhibition of aortic histidine decarboxylase (HD) through administration of alpha-hydrazinohistidine (alpha-HH, MK785, Regis Chemical Co., 25 mg/kg, i.p. at 12-h intervals). Additional rabbits were maintained on either the cholesterol diet or on Purina Rabbit Chow without cholesterol. Results indicate that administration of alpha-HH for the 2-week period produced a 31% reduction (P less than 0.05) in aortic HD activity in those rabbits maintained on the cholesterol diet, and that concurrently there was a 51% reduction in aorta albumin uptake (P less than 0.025) and a 63% reduction in the extent of oil red O staining. By regression analysis a significant correlation coefficient (r = 0.71, P less than 0.005) was obtained between the aortic albumin uptake and the aortic histamine forming capacity (HFC) in rabbits maintained on this cholesterol diet. These findings indicate that the aortic HD system may be an important enzymatic coupler involved in vascular permeability alterations occurring early in the atherogenic sequence.     

Familial hypercholesterolemia supravalvular aortic stenosis and extensive atherosclerosis

Familial hypercholesterolemia is an autosomally dominant disorder caused by various mutations in low-density lipoprotein receptor genes. This can lead to premature coronary atherosclerosis and cardiac-related death. The symptoms are more severe in the homozygous type of the disease. Premature malignant atherogenesis leading to aortic root abnormalities causing supravalvular aortic stenosis is rare. Our case demonstrates the diagnostic imaging findings of the phenotype of patients who have severe elevated LDL with familial hypercolesterolemia.     

Treatment of right heart thromboemboli

BACKGROUND: The presence of right heart thromboemboli complicating pulmonary thromboemboli carries with it an increased mortality rate compared to pulmonary thromboemboli alone, but little is known about the optimal management of this difficult clinical situation. This fact is highlighted in the case study of a patient with a 19-cm right atrial thrombus complicating bilateral pulmonary thromboemboli. STUDY OBJECTIVES: We sought to determine the effects of anticoagulation therapy, thrombolysis, and surgical embolectomy on mortality rate in patients with right heart thromboemboli. DESIGN: Retrospective analysis of all reported cases in the English language literature (1966 to 2000) of right heart thromboembolism in which age, sex, therapy, and outcome were reported. MEASUREMENTS AND RESULTS: We analyzed 177 cases of right heart thromboembolism. Pulmonary thromboembolism was present in 98% of the cases. The patients were evenly divided by gender with an average age of 59.8 years (SD, 16.6 years) years. Dyspnea (54.2%), chest pain (22.6%), and syncope (17.5%) were the most common presenting symptoms. The treatments administered were none (9%), anticoagulation therapy (35.0%), surgical procedure (35.6%), or thrombolytic therapy (19.8%). The overall mortality rate was 27.1%. The mortality rate associated with no therapy, anticoagulation therapy, surgical embolectomy, and thrombolysis was 100.0%, 28.6%, 23.8%, and 11.3%, respectively. Using multivariate modeling with survival as the primary outcome, age and gender were not associated with mortality rate, but thrombolytic therapy was associated with an improved survival rate (p < 0.05) when compared either to anticoagulation therapy or surgery. CONCLUSION: The presence of right heart thromboemboli may have diagnostic and therapeutic implications in pulmonary thromboembolism patients. A well-designed prospective, randomized trial is needed to determine the optimal treatment of right heart thromboemboli.     

Smoking, atherosclerosis and risk of abdominal aortic aneurysm

AIMS: The role of cardiovascular risk factors and atherosclerosisin the aetiology of abdominal aortic aneurysms is not well understood.The aim of this study was to determine the association betweenatherosclerosis and aortic aneurysm in the general populationand the extent to which cardiovascular risk factors might increasethe risk of aneurysm independently of an effect on atheroscleroticdisease. METHODS AND RESULTS: In the Edinburgh Artery Study, 1592 men and women aged 55–74years were followed prospectively over a period of 5 years.Forty subjects were identified as having an abdominal aorticaneurysm and, for each, five controls were randomly selected.Cases showed a higher prevalence of cardiovascular disease (P0·001)and had a lower ankle brachial pressure index (P0·01).Current and recent ex-cigarette smokers had an increased riskof aortic aneurysm compared with long time ex-smokers and neversmokers (odds ratio 3·08, 95% CI 1·53 to 6·21Adjustment for concurrent atherosclerotic disease reduced theodds ratio to 2·63 (95% CI 1·26 to 5·45).The risk of aortic aneurysm was not related to elevation indiastolic blood pressure or in serum cholesterol. CONCLUSIONS: These findings indicate that atherosclerotic disease is associatedwith risk of aortic aneurysm in the general population. In addition,cigarette smoking appears to have a direct effect on the riskof aortic aneurysm which is independent of atherosclerosis.     

Risk factors of atherosclerosis and aortic pulse wave velocity

Aortic pulse wave velocity (PWV) is a noninvasive technique that can estimate aortic stiffness or organic change quantitatively. The authors examined the correlation between age and the PWV value in 113 subjects and also examined the relationship between atherosclerotic associated diseases and PWV. A positive correlation was observed between age and the PWV value. No significant difference was found in the PWV value between groups with and without risk factors of atherosclerosis. No significant difference was observed in the PWV value between groups with and without a history of atherosclerotic disease.     

Catecholamine-induced aggravation of aortic and coronary atherosclerosis in monkeys

Advanced aortic and coronary atherosclerosis was produced in rhesus monkeys by means of two procedures; (a) high fat and cholesterol feeding for 7 months, and (b) this diet coupled with daily i.v. injection of adrenaline (50 μg/kg body weight). A total of 83% of the monkeys subjected to procedure (b) developed markedly advanced atherosclerosis in the form of fibrous plaques in the aorta and coronary artery, while these lesions were much less frequent in the other group. The ratio of total to free serum cholesterol, significantly increased and the aortic cholesterol content was very high in monkeys subjected to both the atherogenic diet and adrenaline injections. It is suggested that catecholamines cause vascular injury and, in the presence of hyperlipidaemia, cause accelerated and aggravated atherosclerosis.     

Are aortic aneurysms caused by atherosclerosis?

BACKGROUND. The emerging controversy concerning the causal role of atherosclerosis in the development of aortic aneurysms was examined using the accumulated clinical and autopsy data obtained during a 20-year follow-up of a cohort of more than 8,000 men of Japanese ancestry in Hawaii. METHODS AND RESULTS. Analyses of 174 clinical incident events indicated that there were two types of aneurysmal disease, 151 aortic aneurysms and 23 aortic dissections. The baseline risk factors that predicted the clinical aortic aneurysms were the same factors that predicted aortic atherosclerosis in the same cohort, namely, high blood pressure, high serum cholesterol, and cigarette smoking. These same risk factors were also significantly associated with the occurrence of 27 aortic aneurysms among 293 autopsied men. The less common aortic dissections had an age-specific incidence pattern indicative of an innate susceptibility precipitated by an exposure to another factor. This pattern was consistent with the findings that the incidence of aortic dissections was predicted mainly by baseline high blood pressure. CONCLUSIONS. From the perspective of prevention, it appears that the risk factors for aortic atherosclerosis and probably atherosclerosis itself are necessary elements in the causal pathway for the great majority of aortic aneurysms in this cohort.     

Assessment of aortic atherosclerosis with transesophageal echocardiography]

OBJECTIVE: To image the thoracic aorta by transesophageal echocardiography (TEE) and study atherosis (morphology and extent of atheroma plaques) and sclerosis (stiffness) and secondarily correlate them with serum lipid levels (cholesterol, HDL, LDL and triglycerides). METHODS: We studied 29 patients (pts) who underwent TEE electively (male 18 pts, age 57.8 +/- 14.6 years). The parameters evaluated were: the stiffness coefficient = ln (PAsist/PAdiast)/(Dsyst/Dmin), and the morphology, location and extent of atheroma plaques. The systolic distension (Dsyst) was the difference between the maximal and the minimal dimensions (Dmin) of the aortic diameter measured by M mode. The lesions were classified in 4 degrees (0-3): 0--normal intima, 1--intimal thickening, 2--atheroma, 3--complicated lesion. Five aortic segments were studied: arch, D1-D4 (descending aorta at 5 cm intervals from the first 25 cm distal of the incisors line). We calculated the individual score = 1 x theta 1/180 + 2 x theta 2/180 + 3 x theta 3/180, theta n represents the angles occupied by the lesions and n (1-3) the severity of atherosis of each lesion. The total atherosis index (TAI) was sigma scores/(n. degree of visualized segments). RESULTS: The arch was not visualized in 3 pts, and the segment D4 was only visualized in 3 pts. TAI mean = 0.82 +/- 0.74, stiffness coefficient mean (SC) = 9.56 +/- 15.072. There were no significant correlations between the lipid levels and the TAI or SC. The only significant positive correlations were: TAI vs age (r = 0.62, p < 0.001) and SC and diastolic blood pressure (BP) (r = 0.42, p < 0.05). CONCLUSIONS: The best visualized segments belong to the descending aorta (25 to 40 cm from the incisors). In this group of patients the lipid levels did not seem to be a preponderant factor in aortic atherosclerosis. The most important factors were age for atherosis and BP for sclerosis.