Dilation and reduced distensibility of carotid artery in patients with abdominal aortic aneurysms

Increased diameter and stiffness of elastic but not muscular arteries in men with abdominal aortic aneurysm

It has been proposed that formation of abdominal aortic aneurysm (AAA) is part of a systemic arterial dilatative disease. However, arteries in the upper extremities are scarcely studied and it remains unclear whether both muscular and elastic arteries are affected by the proposed systemic arterial dilatation. The aim of this study was to investigate the diameter and stiffness of muscular and elastic arteries in arterial branches originating from the aortic arch. Twenty-six men with AAA (69 ± 4 yr) and 57 men without AAA (70 ± 5 yr) were included in the study. Ultrasound was used to examine the distal and proximal brachial artery, axillary artery, and common carotid artery (CCA), and measurement of diameter and diameter change was performed with wall-tracking software. Blood pressure measurements were used to calculate local arterial wall stiffness indices. The AAA cohort presented larger arterial diameters in the CCA and axillary artery after adjustment for body surface area (P = 0.002, respectively), whereas the brachial artery diameters were unchanged. Indices of increased stiffness in CCA (e.g., lower distensibility, P = 0.003) were seen in subjects with AAA after adjustments for body mass index and mean arterial blood pressure. This study supports the theory of a systemic arterial dilating diathesis in peripheral elastic, but not in muscular, arteries. Peripheral elastic arteries also exhibited increased stiffness, in analogy with findings in the aorta in AAA.NEW & NOTEWORTHY We present data partially supporting the notion of abdominal aortic aneurysm being a systemic vascular disease with focal manifestation in the abdominal aorta, from two well-defined groups recruited from a regional screening program. We show that elastic arteries distal from the aorta exhibit vascular alterations without aneurysmal formation in subjects with AAA compared with controls while muscular arteries seem unaffected.

Prevalence of aortic aneurysms and dissections in patients with systemic vessel aneurysms and dissections; matched case-control study using a national sample cohort

Objective

Aneurysms in systemic arteries are rare, and little is known about their relationship with aortic aneurysms. In this study, we aimed to evaluate the prevalence of aortic aneurysms and dissections (AAD) in patients with other systemic vessel aneurysms and dissections (OVAD) and identify their potential risk factors.

Methods

This cross-sectional study used a nationwide representative cohort sample from the Korea National Health Insurance Service-National Sample Cohort database. We defined OVAD as systemic vessel aneurysms and dissections excluding intracranial and aortic dissections and aneurysms. With a total of 690 OVAD patients and 2,760 non-OVAD matched controls, we investigated the prevalence of AAD in patients with OVAD and potential risk factors for their concurrence using the χ2 test and logistic regression.

Results

The prevalence of AAD in patients with OVAD was 10.6% (73/690) and 0.3% (9/2,760) in patients with non-OVAD. The adjusted odds ratio (OR) for having concurrent AAD with OVAD was 37.56 (95% CI: 18.29-77.12, p < 0.001) after stratification by sex, age, income, region of residence and after adjustment for hypertension, diabetes mellitus, dyslipidemia, and extent of disability. The adjusted ORs of AAD were significantly higher in females [adjusted OR = 47.63 (95% CI: 10.72-211.55)], and individuals aged ≥60 years [adjusted OR = 28.18 (95% CI: 13.42-59.17)], as well as those without hypertension [adjusted OR = 95.44 (95% CI: 18.21-500.23)], diabetes mellitus [adjusted OR = 46.39 (95% CI: 18.85-114.17)], without dyslipidemia [adjusted OR = 60.99 (95% CI: 20.83-178.56), p < 0.001 for all]. The prevalence of AAD significantly differed by according to specific sites of OVAD in carotid artery, upper extremity artery, iliac artery, lower extremity artery, and splanchnic artery (p < 0.001 for all).

Conclusions

The prevalence of AAD in patients with OVAD was 37.56 times higher than that in the matched population. We may approach aneurysms as systemic diseases and further investigations of pathophysiology would help to clarify the relationships between AAD and OVAD.

Carotid artery vasoreactivity correlates with abdominal aortic vasoreactivity in young healthy individuals but not in patients with abdominal aortic aneurysm

Background

Sympathetic stimulation of central arteries, such as coronary and carotid arteries, cause vasodilation in healthy subjects, but vasoconstriction in those with increased cardiovascular risk. This study compared vasoreactivity to sympathetic stimulation between abdominal aorta and carotid artery in healthy young individuals (young group, n = 20), in patients with abdominal aortic aneurysm (AAA group, n = 20) and in a healthy older group, age- and gender matched with AAA group (matched group, n = 18).

Method

All subjects underwent cold pressor test, while performing concomitantly duplex ultrasound of abdominal aorta and carotid artery vasoreactivity. Observer-independent software was used to analyze and calculate magnitude and timing of maximum vasodilation or vasoconstriction. Pearson's correlation coefficient was calculated to investigate vasoreactivity between arteries.

Results

Carotid artery reactivity [Interquartile range 25%, Interquartile range 75%] did not significantly differ between the young, matched and AAA group (3.5% [1.4, 4.7], 2.6% [2.0, 4.1] and 2.2% [-1.9, 3.7], respectively, p = 0.301). Abdominal aortic responsiveness demonstrated larger differences between young (4.9% [-0.2, 8.4]), matched (3.3% [-2.5, 4.4]) and individuals with AAA (0.5% [-3.9, 4.1], p = 0.059). Pooled analysis showed a significant correlation between carotid and abdominal aortic vasoreactivity (r = 0.444, p = 0.001). Subgroup analyses demonstrated significant correlation between both arteries in young (r = 0.636, p = 0.003), but not matched (r = −0.040, p = 0.866) or AAA group (r = 0.410, p = 0.129).

Conclusions

Sympathetic stimulation induces powerful vasodilation of the carotid artery and abdominal aorta, which is significantly correlated in healthy individuals. No such correlation is present in abdominal aortic aneurysm patients. This suggests the aneurysm alters local abdominal aorta vasoreactivity, but not the carotid artery.

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Vasoreactivity is significantly correlated between carotid and abdominal aorta.

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Presence of abdominal aneurysm was associated with local impaired vasoreactivity.

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Abdominal aorta demonstrates a stronger vasoreactivity than the carotid artery.

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Vasoreactivity of the carotid artery did not differ between groups.

Assessment of Upper Extremity Venous Compliance in Patients With Abdominal Aortic Aneurysms

OBJECTIVE

Abdominal aortic aneurysm (AAA) is associated with morphological and functional changes in both aneurysmal and non-aneurysmal arteries. However, it remains uncertain whether similar changes also exist in the venous vasculature. The aim of this study was to evaluate global venous function in patients with AAA and controls.

METHODS

This experimental study comprised 31 men with AAA (mean ± standard deviation age 70.0 ± 2.8 years) and 29 male controls (aged 70.6 ± 3.4 years). Venous occlusion plethysmography (VOP) was used to evaluate arm venous compliance at venous pressures between 10 and 60 mmHg in steps of 5 mmHg. Compensatory mobilisation of venous capacitance blood (capacitance response) was measured with a volumetric technique during experimental hypovolaemia induced by lower body negative pressure (LBNP).

RESULTS

The VOP induced pressure-volume curve was significantly less steep in patients with AAA (interaction, p < .001), indicating lower venous compliance. Accordingly, the corresponding pressure-compliance curves displayed reduced venous compliance at lower venous pressures in patients with AAA vs. controls (interaction, p < .001; AAA vs. control, p = .018). After adjusting for arterial hypertension, diabetes mellitus, hyperlipidaemia, chronic obstructive pulmonary disease, and smoking, VOP detected differences in venous compliance remained significant at low venous pressures, that is, at 10 mmHg (p = .008), 15 mmHg (p = .013), and 20 mmHg (p = .026). Mean venous compliance was negatively correlated with aortic diameter (r = -.332, p = .010). Mobilisation of venous capacitance response during LBNP was reduced by approximately 25% in patients with AAA (p = .030), and the redistribution of venous blood during LBNP was negatively correlated with aortic diameter (r = -.417, p = .007).

CONCLUSION

Men with AAA demonstrated reduced venous compliance and, as a result, a lesser capacity to mobilise peripheral venous blood to the central circulation during hypovolaemic stress. These findings imply that the AAA disease may be accompanied by functional changes in the venous vascular wall.

Greater aortic inflammation and calcification in abdominal aortic aneurysmal disease than atherosclerosis: a prospective matched cohort study

Objective

Using combined positron emission tomography and CT (PET-CT), we measured aortic inflammation and calcification in patients with abdominal aortic aneurysms (AAA), and compared them with matched controls with atherosclerosis.

Methods

We prospectively recruited 63 patients (mean age 76.1±6.8 years) with asymptomatic aneurysm disease (mean size 4.33±0.73 cm) and 19 age-and-sex-matched patients with confirmed atherosclerosis but no aneurysm. Inflammation and calcification were assessed using combined 18F-FDG PET-CT and quantified using tissue-to-background ratios (TBRs) and Agatston scores.

Results

In patients with AAA, 18F-FDG uptake was higher within the aneurysm than in other regions of the aorta (mean TBRmax2.23±0.46 vs 2.12±0.46, p=0.02). Compared with atherosclerotic control subjects, both aneurysmal and non-aneurysmal aortae showed higher 18F-FDG accumulation (total aorta mean TBRmax2.16±0.51 vs 1.70±0.22, p=0.001; AAA mean TBRmax2.23±0.45 vs 1.68±0.21, p<0.0001). Aneurysms containing intraluminal thrombus demonstrated lower 18F-FDG uptake within their walls than those without (mean TBRmax2.14±0.43 vs 2.43±0.45, p=0.018), with thrombus itself showing low tracer uptake (mean TBRmax thrombus 1.30±0.48 vs aneurysm wall 2.23±0.46, p<0.0001). Calcification in the aneurysmal segment was higher than both non-aneurysmal segments in patients with aneurysm (Agatston 4918 (2901-8008) vs 1017 (139-2226), p<0.0001) and equivalent regions in control patients (442 (304-920) vs 166 (80-374) Agatston units per cm, p=0.0042).

Conclusions

The entire aorta is more inflamed in patients with aneurysm than in those with atherosclerosis, perhaps suggesting a generalised inflammatory aortopathy in patients with aneurysm. Calcification was prominent within the aneurysmal sac, with the remainder of the aorta being relatively spared. The presence of intraluminal thrombus, itself metabolically relatively inert, was associated with lower levels of inflammation in the adjacent aneurysmal wall.

[Ten-year results of abdominal aortic and great vessels aneurysms management]

AIM

To present own 10-year experience of abdominal aortic and great vessels aneurysms management.

MATERIAL AND METHODS

There were 369 patients with abdominal aortic aneurysms (AAA) for the period 1995-2016 at the Yaroslavl Regional Clinical Hospital. 25% of patients suffered from abdominal aortic and great vessels aneurysms. Mean age was 70.3±7.5. There were 79 (86%) men and 13 (14%) women. 93 patients had 212 aneurysms of other sites besides AAA (from 1 to 6 aneurysms in each case). 63 (68%) patients have been treated and followed-up for the period from 1 to 10 years (mean 105±11.8 months).

RESULTS

1-, 5-, 8- and 10-year survival after AAA repair was 98%, 81%, 54% and 38% respectively.

CONCLUSION

The common complications of great vessels aneurysms are distal thrombosis and embolism (40%). Ruptures of aneurysms are less common (13%). These complications require active surgical tactics that allows to preserve the limbs in 85% of patients. Progressive nature of disease in overwhelming numbers of patients (95%) with aneurysms enlargement and their occurrence in other sites requires regular lifelong clinical examination with mandatory ultrasound 2 times per year.

The Effect of ACE Gene Polymorphisms on Doppler Blood Flow Parameters of Carotid and Brachial Arteries in Patients With Myocardial Infarction

The authors investigated the relationship between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and the blood flow characteristics of common carotid (CCA) and brachial arteries (BA) by color Doppler ultrasound (CDUS) in patients with acute anterior myocardial infarction (AAMI). Sixty four patients (11 women and 53 men), aged 25 to 77 years, with AAMI were studied. The ACE genotypes were established. Peak-systolic (PSV) and end-diastolic velocity (EDV) of right and left CCA, PSV of right BA, and intimal-medial thickness (IMT) of both CCAs were measured by CDUS. All results were evaluated statistically. The ACE genotypes were distributed as follows: 43.8% DD, 43.8% ID, and 12.5% II. PSVs of BA and both CCAs were lower in patients with DD and ID than with II (p<0.05). EDVs of both CCAs were also lower in the same groups, but statistically not significant (p>0.05). IMTs of both CCAs did not differ among patients with various ACE genotypes (p>0.05). These results suggest that ACE I/D polymorphism influences Doppler blood flow parameters of both BA and CCA, but does not affect IMT of CCA.

Pitavastatin calcium improves endothelial function and delays the progress of atherosclerosis in patients with hypercholesterolemia

BACKGROUND

Statins have proven efficacy in inhibiting the onset and progress of atherosclerosis. The effectiveness of pitavastatin in reversing carotid atherosclerosis associated with hypercholesterolemia (HC) is unknown.

OBJECTIVES

To explore the simultaneous effects of pitavastatin calcium on brachial arterial flow-mediated vasodilatation (FMD), carotid intima-media thickness (IMT), and arterial stiffness (β), three surrogate markers of atherosclerosis were studied in HC patients.

METHODS

A randomized, double-blind trial was performed with 40 HC subjects who fulfilled the inclusion/exclusion criteria. Patients were given pitavastatin calcium 1 mg/d (Group 1) or 2 mg/d (Group 2) for 8 weeks. There were 20 patients in each group, and 30 gender- and age-matched healthy subjects as controls were recruited. FMD of the brachial artery, carotid IMT, and arterial stiffness indicated by β were measured at baseline and at 8 weeks after starting pitavastatin calcium therapy using ultrasound techniques. Biochemical tests were also made on all subjects.

RESULTS

At baseline, higher total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), reduced FMD, and increased β and IMT were observed in HC patients (P<0.001 for all) compared with controls. After 8 weeks, TC was decreased by 20.59%/27.56% and LDL-C 30.92%/35.64%, respectively, in comparison to baseline groups; the HC groups had reduced β and improved endothelial function over the 8-week follow-up (P<0.05-0.001); nonetheless, no significant alterations of IMT were found (P>0.05). Significant negative interactions between TC/LDL and FMD (P<0.05-0.001), positive interactions between TC and IMT (P=0.003) and between TC/LDL and β (P<0.001-0.000) were found.

CONCLUSIONS

Treatment with pitavastatin calcium exerted favorable effects on endothelial function and arterial stiffness. It also improved carotid atherosclerosis in patients with HC.

Increased cardiovascular risk without generalized arterial dilating diathesis in persons who do not have abdominal aortic aneurysm but who are first-degree relatives of abdominal aortic aneurysm patients

There is a strong genetic predisposition towards abdominal aortic aneurysm (AAA), but it is unknown whether persons without AAA but with first-degree relatives who are AAA patients have a generalized dilating diathesis, defect arterial wall mechanics, or increased cardiovascular risk. The aim of the study was to investigate arterial diameters and wall mechanics at multiple arterial sites in these subjects and compare them with controls without a family history of AAA. This study included 118 first-degree relatives of patients with AAA and 66 controls (age: 40-80 years). The abdominal aorta, common carotid artery, common femoral artery, and popliteal artery were investigated by echo-tracking ultrasound. The relatives had no arterial dilatation, but they did tend to have smaller diameters than controls. Relatives had a higher heart rate, diastolic blood pressure, and mean arterial pressure than controls. The distensibility coefficient and the compliance coefficient were decreased in all arteries in male relatives, adjusted for age and smoking; these coefficients were normalized after adjustment for mean arterial pressure and heart rate. Female relatives had a lower compliance coefficient in the abdominal aorta, adjusted for age and smoking. After adjustment for mean arterial pressure and heart rate, the difference disappeared. No general arterial dilatation in relatives without AAA was found, supporting the hypothesis that the dilating diathesis is linked to the aneurysmal manifestation in the abdominal aorta. Although the threat of aneurysmal dilatation and rupture seems to be lacking in these subjects, heart rate, blood pressure, and arterial wall stiffness were all increased, which may indicate a higher risk of developing cardiovascular morbidity and mortality.

Expression of cytoskeleton and energetic metabolism-related proteins at human abdominal aortic aneurysm sites

OBJECTIVE

The purpose of this study was to evaluate the expression of proteins related to cytoskeleton and energetic metabolism at abdominal aortic aneurysm (AAA) sites using proteomics. Several remodeling-related mechanisms have been associated with AAA formation but less is known about the expression of proteins associated with cytoskeleton and energetic metabolism in AAAs.

METHODS

AAA samples (6.73 ± 0.40 cm size) were obtained from 13 patients during elective aneurysm repair. Control abdominal aortic samples were obtained from 12 organ donors. Proteins were analyzed using two-dimensional electrophoresis and mass spectrometry.

RESULTS

The expression of filamin was increased in the AAA site compared to control abdominal aortic samples while microfibril-associated glycoprotein-4 isotype 1, annexin A5 isotype 1, and annexin A2 were reduced compared with control abdominal aortic samples. Reduction in expression level of energetic metabolism-associated proteins such as triosephosphate isomerase, glyceraldehyde 3-phosphate dehydrogenase, and cytosolic aldehyde dehydrogenase was also observed in AAAs compared to controls. Reduction of triosephosphate isomerase expression was also observed by Western blot, which was accompanied by diminished triosephosphate isomerase activity. At the AAA site, pyruvate dehydrogenase expression was reduced and the content of both lactate and pyruvate was increased with respect to controls without changes in lactate dehydrogenase activity.

CONCLUSIONS

The present results suggest that an anaerobic metabolic state may be favored further to reduce the expression of cytoskeleton-related proteins. The better knowledge of molecular mechanism involved in AAAs may favor development of new clinical strategies.

Pathophysiology and epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are found in up to 8% of men aged >65 years, yet usually remain asymptomatic until they rupture. Rupture of an AAA and its associated catastrophic physiological insult carries overall mortality in excess of 80%, and 2% of all deaths are AAA-related. Pathologically, AAAs are associated with inflammation, smooth muscle cell apoptosis, and matrix degradation. Once thought to be a consequence of advanced atherosclerosis, accruing evidence indicates that AAAs are a focal representation of a systemic disease of the vasculature. Risk factors for AAAs include increasing age, male sex, smoking, and low HDL-cholesterol levels. Familial associations exist and although susceptibility genes have been described on the basis of candidate-gene studies, robust genetic studies have failed to discover causative gene mutations. The surgical management of AAAs has been revolutionized by minimally invasive endovascular repair. Ongoing randomized trials will establish whether endovascular repair confers a survival advantage over open surgery for patients with a ruptured AAA. In many countries, centralization of vascular surgical services has largely been driven by the improved outcomes of elective aneurysm surgery in specialized centers, the widespread adoption of endovascular techniques, and the introduction of screening programs.

Chronic kidney disease is associated with increased carotid artery stiffness without morphological changes in participants of health check-up programs

BACKGROUND AND METHODS

Patients with chronic kidney disease (CKD) show a much higher risk of cardiovascular disease. However, the mechanisms underlying this association and the impact of CKD on behaviors of the vascular walls have not been fully clarified. Using ultrasonography, this study investigated associations of CKD (estimated glomerular filtration rate <60 ml/min/1.73 m(2) and/or presence of proteinuria) with both elasticity (stiffness β index) of the carotid artery and intimal atherosclerotic changes in participants of health check-up programs (n=3406, 63% men; mean age, 58.8 years).

RESULTS

Stiffness β was significantly higher in CKD subjects (7.49 ± 0.14) than in non-CKD subjects (6.87 ± 0.05, P<0.001). This significant difference was maintained in a multiple adjusted model including conventional risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking and obesity (7.20 ± 0.14 vs. 6.91 ± 0.05, P=0.043). No significant differences in intima-media complex thickness or plaque score were seen between CKD and non-CKD subjects.

CONCLUSION

In participants of health check-up programs, CKD was associated with increased carotid arterial stiffness without intimal disease, independently of conventional risk factors. These findings indicate that CKD may predispose the carotid arteries to earlier development of arteriosclerosis, characterized by increased arterial stiffness.

Review of Current Theories for Abdominal Aortic Aneurysm Pathogenesis

Atherosclerotic plaques are a feature of abdominal aortic aneurysms (AAAs). Atherosclerosis and AAA appear to share similar risk factors. These observations have led to the conclusion that AAAs are a consequence of advanced atherosclerosis.

This review explores current theories regarding the pathogenesis of AAA and their implications for treatment.

A systematic literature search was conducted using the search terms abdominal aortic aneurysm, atherosclerosis, pathogenesis, and systemic disease. Articles were categorized according to the association of AAAs with atherosclerosis, arteriomegaly, peripheral aneurysm, systemic expression, genetics, autoimmunity, oxidative stress, and systemic disease. Twenty-nine articles reporting changes in the systemic vasculature associated with AAA and 12 articles examining the shared risk factor hypothesis were identified.

There is insufficient evidence to confirm that AAAs are the result of advanced atherosclerosis. The bulk of evidence points to AAA disease being a systemic disease of the vasculature, with a predetermined genetic susceptibility leading to a phenotype governed by environmental factors.

Increased carotid artery stiffness without atherosclerotic change in patients with aortic dissection

The arterial properties and pathogenesis of aortic dissection remain obscure. To examine the arterial properties of patients with aortic dissection, the authors studied the ultrasonographic characteristics of the carotid artery in patients with an aortic dissection (AD, n = 86), and compared these findings with data of patients suffering from arteriosclerosis obliterans (ASO, n = 151), coronary artery disease (CAD, n = 163), and with healthy controls (HC, n = 77). Atherosclerotic intimal changes, such as intima-media thickness (IMT) and plaque formation, were milder in AD than in ASO or CAD (IMT: 0.83 +/- 0.16 vs 0.93 +/- 0.20/0.86 +/- 0.17 mm, p < 0.05; plaque number: 0.6 +/- 1.1 vs 2.7 +/- 2.4/2.5 +/- 2.1, p <0.05). Luminal diameter in AD, ASO, and CAD was significantly higher than in HC. The luminal distensibility in AD was decreased compared with HC but was the same as in ASO and CAD. Intra-AD group analysis showed that in patients with an intramural hematoma (IMH) or a dissection with a thrombosed false lumen (TLF) the IMT was higher than in patients with a classic dissection. In addition, plaque formation was more severe in AD patients with a coexisting abdominal aortic aneurysm (AAA). Reduced distensibility without severe intimal disease was found in AD. These findings suggest that patients with AD may have several arterial alterations, including structural abnormalities. Patients with IMH, TFL, or coexisting AAA may differ from patients who have a classic type of dissection or who do not have AAA, in terms of arterial characteristics including intimal disease and wall elastic property, and the initiating cause of the dissection.

Superior mesenteric artery aneurysm stent graft

Visceral artery aneurysms represent 0.1% to 0.2% of all vascular aneurysms. They are mostly asymptomatic, but rupture is associated with a high mortality rate. We present a case of an asymptomatic aneurysm of the proximal superior mesenteric artery in a 64-year-old man that was successfully treated by implantation of a covered stent graft. The use of endovascular techniques to manage visceral artery aneurysms should be considered.

The Association of C-Reactive Protein Levels With Carotid Intima-Media Complex Thickness and Plaque Formation in the General Population

BACKGROUND AND PURPOSE

An inflammatory response has been associated with the development of atherosclerosis. Our aim was to clarify which atherosclerotic changes (intima-media complex thickness [IMT] increase, plaque formation, and arterial dilatation) are associated with C-reactive protein (CRP) levels and to determine whether there are any gender differences.

METHODS

Carotid ultrasound and measurement of high-sensitivity CRP (hs-CRP) levels were performed in 2056 subjects selected from a general population (mean age 58.3 years; 1290 men).

RESULTS

In both genders, IMT significantly increased with increasing hs-CRP quartile (P<0.001), but this relationship disappeared after adjustment for age and other traditional cardiovascular risk factors. In men, but not women, carotid luminal diameter significantly increased with increasing hs-CRP levels (P<0.05), but again, this relationship disappeared with adjustment for age and other risk factors. However, in men, but not women, plaque score increased significantly with increasing hs-CRP quartile (P<0.01), even after adjustment for age and other traditional risk factors.

CONCLUSIONS

CRP level was closely associated with early atherosclerotic changes represented by carotid plaque formation. However, the IMT increase was strongly associated with aging and other traditional cardiovascular risk factors rather than CRP level. In the general population, CRP may serve as a complementary and quantitative marker for atherosclerotic plaque formation in men but not women.

Implications of carotid arteriomegaly in patients with aortic aneurysm

The pathophysiology of aortic aneurysm is complex and it has remained unclear how frequently arteriomegaly, a diffuse dilatation of the artery, is associated with aneurysm. Therefore, ultrasonic study of the carotid artery was conducted to clarify this issue in a large number of subjects. Carotid ultrasonography was performed in 1,108 Japanese men aged 50 or older, and the results of 379 patients with arteriosclerotic aortic aneurysm (AA) were compared with those of 211 patients with peripheral arterial disease, 65 patients with aortic dissection, 232 hypertensive subjects, and 221 normotensive subjects. The carotid diameter was measured bilaterally at two points on the common carotid artery, and we defined carotid arteriomegaly as an arterial diameter in the 95th percentile or above that in the normotensive control group according to the relevant age subgroups. The incidence of carotid arteriomegaly in the AA group (25.9%) was significantly higher than in the other groups (p < 0.01) even when adjusted for body height and blood pressure. In the arteriomegaly subgroup, hypertension and cigarette smoking was significantly more frequent than in the non-dilated artery subgroup. This study demonstrates that one fourth of patients with aortic aneurysm have arteriomegaly as a generalized systemic abnormality in the arterial wall.

Systemic dilation diathesis in patients with abdominal aortic aneurysms: a role for matrix metalloproteinase-9?

INTRODUCTION

Accumulating evidence suggests that patients with abdominal aortic aneurysm (AAA) suffer from a systemic dilating condition affecting all arteries. Matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), appear to be involved in aneurysm formation, as evidenced by increased aortic tissue MMP activity and plasma MMP levels in patients with AAA. Hypothesizing that an imbalance in plasma MMP/TIMP level might be associated with a systemic dilation diathesis, we studied mechanical vessel wall properties of non-affected arteries of patients with either AAA or aorto-iliac obstructive lesions in association with plasma MMP-9 and TIMP-1 levels.

METHODS

Twenty-two patients with AAA and 12 with aorto-iliac occlusive disease (AOD) were included. Diastolic diameter (d) and distension (Deltad) were measured at the level of the common carotid artery (CCA) and suprarenal aorta (SA) using ultrasonography. Distensibility (DC) and compliance (CC) were calculated from d, Deltad and brachial pulse pressure. Plasma MMP-9 and TIMP-1 were determined with specific immunoassays.

RESULTS

The average (+/-SD) age was 72.3+/-5.6 and 65.0+/-8.2 years for the AAA and AOD patients, respectively, (P=0.005). CCA diameter was 9.1+/-1.3mm in AAA patients and AOD 7.8+/-1.4mm in AOD patients, P=0.009. This difference persisted after correction for age. Plasma MMP-9 and TIMP-1 did not differ significantly between AAA and AOD patients. In the total 34 patients, the MMP-9/TIMP-1 ratio was correlated inversely with distensibility (r=-0.74, P=0.002) and to compliance (r=-0.58, P=0.024) of the suprarenal aorta.

CONCLUSIONS

The CCA diameter was larger in AAA patients compared to AOD patients. MMP-9/TIMP-1 ratio was associated with decreased distensibility and compliance of the suprarenal aorta. These data support the idea that AAA patients exhibit a systemic dilation diathesis, which might be attributable to MMP/TIMP imbalances.

Pretreatment with the Free Radical Scavenger Edaravone Prevents Cerebral Hyperperfusion after Carotid Endarterectomy

OBJECTIVE:

Cerebral hyperperfusion syndrome after carotid endarterectomy (CEA) is a rare but potentially devastating complication. The purpose of the present study, which was not a randomized controlled trial but a case cohort study with historical control, was to determine whether pretreatment with a novel free radical scavenger, edaravone, could prevent occurrence of cerebral hyperperfusion after CEA.

METHODS:

Fifty patients with ipsilateral internal carotid artery stenosis (≥70%) underwent CEA with administration of edaravone before internal carotid artery clamping. Preoperative cerebral blood flow and cerebrovascular reactivity (CVR) to acetazolamide were assessed with single-photon emission computed tomography (SPECT). Cerebral blood flow also was measured immediately after CEA and on the 3rd postoperative day.

RESULTS:

Cerebral hyperperfusion (cerebral blood flow increase ≥100% compared with preoperative values) was revealed by SPECT performed immediately after CEA in only one patient (2%), who also exhibited reduced preoperative CVR. The incidence of post-CEA hyperperfusion as revealed by SPECT in the control group (51 CEA patients without administration of edaravone) was significantly higher (16%) (P= 0.0310, control versus treatment group). In addition, in a subgroup of patients with reduced preoperative CVR, the incidence of post-CEA hyperperfusion as revealed by SPECT in the edaravone group (7%) was significantly lower than that in the control group (67%) (P= 0.0029). Logistic regression analysis demonstrated that reduced preoperative CVR and absence of pretreatment with edaravone were significant independent predictors of post-CEA hyperperfusion as revealed by SPECT.

CONCLUSION:

Pretreatment with edaravone can prevent occurrence of cerebral hyperperfusion after CEA.

Delayed Cerebral Hyperperfusion Syndrome Caused by Prolonged Impairment of Cerebrovascular Autoregulation after Carotid Endarterectomy: Case Report

OBJECTIVE AND IMPORTANCE

Cerebral hyperperfusion syndrome is a rare but potentially devastating complication that typically occurs within several days after carotid endarterectomy.

CLINICAL PRESENTATION

A 66-year-old man experienced asymptomatic cerebral hyperperfusion as demonstrated by single-photon emission computed tomography (SPECT) during a 2-week period after undergoing right carotid endarterectomy. This phenomenon occurred despite intensive pharmacological control of blood pressure. On the 28th postoperative day, repeat SPECT demonstrated resolution of hyperperfusion, and intensive blood pressure control was discontinued.

INTERVENTION

Twelve hours later, the patient experienced left motor seizures with secondary generation. SPECT performed 36 hours after the onset of seizures demonstrated the reappearance of hyperperfusion. Intensive blood pressure control was reinstituted and maintained until the 36th postoperative day. On the next day, SPECT demonstrated resolution of hyperperfusion.

CONCLUSION

The present case suggests that cerebral hyperperfusion syndrome may occur at later time points (e.g., 1 mo) after carotid endarterectomy. This delayed hyperperfusion syndrome may be related to prolonged impairment of cerebrovascular autoregulation.

The popliteal artery, an unusual muscular artery with wall properties similar to the aorta: implications for susceptibility to aneurysm formation?

OBJECTIVE

The popliteal artery is, after the aorta, the most common site for aneurysm formation. Why the popliteal artery is more susceptible than other peripheral muscular arteries is unknown. An important factor may be differences in arterial wall composition as compared with other peripheral muscular arteries, which in turn affect wall properties. These are however unknown. We studied the mechanical wall properties of the popliteal artery in healthy subjects.

MATERIAL AND METHODS

An ultrasound echo-tracking system was used to measure pulsatile changes in popliteal diameter in 108 healthy subjects (56 female, 52 male; age range, 9-82 years). In combination with blood pressure, stiffness (beta), strain, cross-sectional artery wall compliance coefficient (CC), and distensibility coefficient (DC) were calculated. Intima-media thickness (IMT) was registered with a Philips P700 ultrasound scanner.

RESULTS

The popliteal diameter increased with age, and was larger in male subjects than in female subjects (P<.001). Fractional diameter change (strain) decreased with age (P<.001), and strain values were lower in male subjects than in female subjects (P<.01). Accordingly, stiffness increased with age (P<.001), with higher stiffness values in male subjects (P<.01). DC decreased with age (P<.001), with lower DC values in male subjects (P<.01). CC decreased with age, with no difference between genders (P<.001). IMT increased with age (P<.001), with higher IMT values in male subjects (P<.001). The increase in IMT did not affect distensibility.

CONCLUSION

The wall properties of the popliteal artery are affected by age and gender, not only with an increase in diameter, but also with an age-related decrease in distensibility, with male subjects having lower distensibility than in female subjects. This seems not to be the behavior of a true muscular artery, but of a central elastic artery, such as the aorta, and might have implications for susceptibility to arterial dilatation, as well as the association of aneurysm formation between the aorta and the popliteal artery.

CLINICAL RELEVANCE

The popliteal artery is, after the abdominal aorta, the most common location for aneurysm formation in the arterial system. Why it is more susceptible than other arteries is unknown. This study shows that the wall function of the popliteal artery differs from other peripheral arteries, and instead show striking similarities to the abdominal aorta, indicating that the functional arrangement of arterial wall components are similar in the two arteries. This may have implications for the susceptibility to aneurysm formation, as well as the association of dilating disease between the popliteal artery and the abdominal aorta.

Prediction and monitoring of cerebral hyperperfusion after carotid endarterectomy by using single-photon emission computerized tomography scanning

OBJECT

The purpose of this study was to determine whether the preoperative measurement of acetazolamide-induced changes in cerebral blood flow (CBF), which is performed using single-photon emission computerized tomography (SPECT) scanning, can be used to identify patients at risk for hyperperfusion following carotid endarterectomy (CEA). In addition, the authors investigated whether monitoring of CBF with SPECT scanning after CEA can be used to identify patients at risk for hyperperfusion syndrome.

METHODS

Cerebral blood flow and cerebrovascular reactivity (CVR) to acetazolamide were measured before CEA in 51 patients with ipsilateral internal carotid artery stenosis (> or = 70% stenosis). Cerebral blood flow was also measured immediately after CEA and on the 3rd postoperative day. Hyperperfusion (an increase in CBF of > or = 100% compared with preoperative values) was observed immediately after CEA in eight of 12 patients with reduced preoperative CVR. Reduced preoperative CVR was the only significant independent predictor of post-CEA hyperperfusion. Forty-three patients in whom hyperperfusion was not detected immediately after CEA did not exhibit hyperperfusion on the 3rd postoperative day and did not experience hyperperfusion syndrome. In two of eight patients in whom hyperperfusion occurred immediately after CEA, CBF progressively increased and hyperperfusion syndrome developed, but intracerebral hemorrhage did not occur. In the remaining six of eight patients in whom hyperperfusion was detected immediately after CEA, the CBF progressively decreased and the hyperperfusion resolved by the 3rd postoperative day.

CONCLUSIONS

Preoperative measurement of acetazolamide-induced changes in CBF, which is performed using SPECT scanning, can be used to identify patients at risk for hyperperfusion after CEA. In addition, post-CEA monitoring of CBF performed using SPECT scanning results in the timely and reliable identification of patients at risk for hyperperfusion syndrome.

Radial, carotid and aortic distensibility in congestive heart failure: effects of high-dose angiotensin-converting enzyme inhibitor or low-dose association with angiotensin type 1 receptor blockade

objectives; The aim of this study was to determine whether in patients with congestive heart failure (CHF) a distensibility (Dist) reduction: 1) similarly occurs in different arteries; 2) is related to CHF severity; and 3) is reversible with treatment. background: Several studies suggest that CHF is accompanied by a reduced arterial Dist.

METHODS

We measured diameter in radial artery, carotid artery (CA) and abdominal aorta (AO) by echotracking. Distensibility was obtained by relating it to blood pressure. Data were collected in 30 patients with CHF (New York Heart Association functional class I to III) under standard treatment with diuretic, digitalis and angiotensin-converting enzyme (ACE) inhibitor in whom CHF severity was assessed by maximum oxygen consumption (VO(2)max) percentage and in 30 age- and gender-matched controls. Patients with CHF were then randomized to maintain standard treatment (n = 10), double the ACE inhibitor dose (n = 10) or add an angiotensin II antagonist (n = 10) and restudied after two months.

RESULTS

Distensibility was markedly reduced in the CHF group in all three vessels (p < 0.01), CA and AO Dist being related to CHF severity (p < 0.05). After two months, Dist did not change in the group maintained under standard treatment, but it increased significantly (p < 0.05) and similarly when the ACE inhibitor dose was doubled or an angiotensin II antagonist was added.

CONCLUSIONS

Congestive heart failure is characterized by a reduction of Dist of large-elastic and middle-sized muscular arteries. The reduction of large-elastic artery Dist is related to the CHF severity. These alterations can be reversed by drugs, effectively interfering with the renin-angiotensin system either at the ACE or at the angiotensin receptor level.

Arterial dimensions in the lower extremities of patients with abdominal aortic aneurysms--no indications of a generalized dilating diathesis

PURPOSE

This study assessed whether there is a dilating diathesis in peripheral arteries of patients with abdominal aortic aneurysms (AAAs).

METHODS

The anteroposterior diameters of the common femoral artery (CFA) and popliteal artery (PA) were measured in 183 consecutive patients with an AAA (158 men, 25 women; age range, 57-78 years) before elective surgery on the AAA and compared with that of healthy age-matched control subjects. The diameter registrations were performed on the right leg by using a noninvasive echo-tracking ultrasound scanning technique.

RESULTS

Eight CFA aneurysms and four PA aneurysms were found in the male patients with AAAs. Of the patients with AAAs in the CFA and in the PA who were investigated, 46% and 49%, respectively, were affected by peripheral vascular occlusive disease (PVOD). The CFA diameters in the patients with AAAs were 97.8% of those in healthy control subjects (P = not significant [NS]). After exclusion of the CFA aneurysms, the diameters were 92.7% of those in healthy control subjects (P = .0003). If patients with PVOD were also excluded, the CFA diameters were 95.2% of those in healthy control subjects (P = .022). The PA diameters in the patients with AAAs were 97.8% of those in healthy control subjects (P = NS). If PA aneurysms were excluded, the diameters were 94.4% of those in healthy control subjects (P = .0003). If patients with PVOD were also excluded, the PA diameters were 96.1% of those in healthy control subjects (P = NS).

CONCLUSION

After excluding the few patients with AAAs who had peripheral aneurysmal disease and the patients with PVOD, no dilating diathesis in CFAs and PAs was found. This supports the hypothesis that specific genetic, or other factors, not present in most AAAs are responsible for the occurrence of concomitant peripheral aneurysms. Furthermore, the generalized vascular dilating diathesis seen in some patients seems to be a specific entity that was not necessarily affiliated with AAA disease.