Long-term Mortality in Patients with Asymptomatic Carotid Stenosis: Implications for Statin Therapy.

OBJECTIVE: Recent studies with asymptomatic carotid patients on best medical management have shown that the annual risk of stroke has decreased to approximately 1%. There is no evidence that a similar decrease in mortality has occurred. In addition, the intensity of statin therapy for these patients has not yet been determined. The aims of this review were to determine (a) the reported long-term all-cause and cardiac-related mortality in patients with asymptomatic carotid stenosis (ACS) > 50%, (b) whether there has been a decrease in mortality in recent years, (c) the available methods of mortality risk stratification, and (d) whether the latest ACC/AHA guidelines on the treatment of serum lipids can be applied to this group of patients. METHODS: Systematic review of PubMed, EuroPubMed, and Cochrane Library and meta-analysis using random effects for pooled proportions were performed regarding long-term all-cause and cardiac-related mortality and the associated risk factors in ACS patients. The last day for literature search was October 30, 2014. RESULTS: Seventeen studies were retrieved reporting 5-year all-cause mortality in 11,391 patients with ACS >50%. The 5-year cumulative all-cause mortality across all 17 studies was 23.6% (95% CI 20.50-26.80). Twelve additional studies, reporting both all-cause and cardiac mortality with a minimum of 2 year follow-up and involving 4,072 patients were identified. Of the 930 deaths reported, 589 (62.9%; 95% CI 58.81-66.89) were cardiac-related. This translates into an average cardiac-related mortality of 2.9% per year. CONCLUSIONS: All-cause and cardiac mortality in ACS patients are very high. Although risk stratification is possible, most patients are classified as high risk. In view of this high risk, aggressive statin therapy is indicated if the new ACC/AHA guidelines on serum lipids are to be adhered to.

Association of ultrasonic texture and echodensity features between sides in patients with bilateral carotid atherosclerosis.

OBJECTIVES: Our objective was to estimate the correlation of echodensity and textural features, using ultrasound and digital image analysis, between plaques in patients with bilateral carotid stenosis. DESIGN: Cross-sectional observational study. METHODS: Patients undergoing carotid endarterectomy were recruited from Vascular Surgery at the Royal Victoria and Jewish General hospitals in Montreal, Canada. Bilateral pre-operative carotid ultrasound and digital image analysis was performed to extract echodensity and textural features using a commercially available Plaque Texture Analysis software (LifeQMedical Ltd). Principal component analysis (PCA) was performed. Partial correlation coefficients for PCA and individual imaging variables between surgical and contralateral plaques were calculated with adjustment for age, sex, contralateral stenosis, and statin use. RESULTS: In the whole group (n = 104), the six identified PCA variables and 42/50 individual imaging variables were moderately correlated (r = .211-.641). Correlations between sides were increased in patients with ≥50% contralateral stenosis and symptomatic patients. CONCLUSION: Textural and echodensity features of carotid plaques were similar between two sides in patients with bilateral stenosis, supporting the notion that plaque instability is determined by systemic factors. Patients with unstable features of one plaque should perhaps be monitored more closely or treated more aggressively for their contralateral stenosis, particularly if this is hemodynamically significant.

Screening for chronic cerebrospinal venous insufficiency (CCSVI) using ultrasound: recommendations for a protocol.

Chronic cerebrospinal venous insufficiency (CCSVI) is a syndrome characterized by stenoses or obstructions of the internal jugular and/or azygos veins with disturbed flow and formation of collateral venous channels. Ultrasound and venographic studies of the internal jugular and azygos venous systems in patients with multiple sclerosis (MS) have demonstrated a high prevalence of CCSVI (mean 71%, range 0-100%; n=1336) associated with activation of collaterals. By contrast, ultrasound and venographic examinations of normal controls and patients without MS have demonstrated a much lower prevalence (mean 7.1%, range 0-22%; n=505). Ultrasound in the form of duplex scanning uses a combination of physiological measurements as well as anatomical imaging and has been used for the detection of CCSVI by different centers with variable results. A high prevalence of obstructive lesions, ranging from 62% to 100%, has been found by some teams in patients with MS compared with a low prevalence (0-25%) in controls. However, others have reported absence of these lesions or a lower prevalence (16-52%). This variability could be the result of differences in technique, training, experience or criteria used. In order to ensure a high reproducibility of duplex scanning with comparable accuracy between centers a detailed protocol with standard methodology and criteria is needed. Also, standardization of the method of reporting of duplex measurements and other findings will facilitate validation of the proposed criteria by different centers. The aim of this document is to produce recommendations for such a protocol and indicate what future research is needed in order to address areas of uncertainty.

The efficacy of a new stimulation technology to increase venous flow and prevent venous stasis.

OBJECTIVES: Electrical stimulation of calf muscles has been shown to be effective in prevention of DVT. The aim was to determine: (a) dependence of venous blood velocity and ejected volume on the rates of stimulated calf contractions: (b) clinical factors affecting efficacy in healthy individuals. METHODS: The maximum intensity stimulus tolerated was applied to calves of 24 volunteers. In popliteal veins, peak systolic velocities (PSV), ejected volume per individual stimulus (stroke volume SV) and ejected total volume flow per minute (TVF) of expelled blood were determined using ultrasound. Stimulation rates from 2 to 120 beats per minute (bpm) were applied. RESULTS: Mean baseline popliteal PSV was 10 cm/s. For stimulation rates between 2 and 8 bpm, the PSV was 10 times higher and reached 96-105 cm/s. Stroke volume (SV) per individual stimulus decreased in a similar fashion. With increasing rates of stimulation the TVF increased by a factor of 12 times (from 20 ml/min to 240 ml/min). CONCLUSION: Electrical stimulation is an effective method of activating the calf muscle pump. Enhancements of popliteal blood velocity and volume flow are key factors in the prevention of venous stasis and DVT. Further studies are justified to determine the stimulation rates in those with a compromised venous system.

Association of plaque echostructure and cardiovascular risk factors with symptomatic carotid artery disease.

AIM: Severity of stenosis remains the main factor for assessing risk of stroke in patients with internal carotid artery (ICA) disease. This study was conducted to investigate the association of plaque echostructure and other established and emerging cardiovascular risk factors with symptomatic ICA disease. METHODS: Cross-sectional study of consecutive patients with significant (>50%) ICA stenosis. Carotid plaque echostructure, smoking, hypertension, diabetes mellitus, serum lipoprotein (a), homocysteine, vitamin B12, folate, cholesterol to high-density lipoprotein ratio, triglycerides, C-reactive protein, and the Framingham risk score were assessed in 124 consecutive patients (70 asymptomatic; 54 symptomatic) with significant (>50%) ICA stenosis. RESULTS: The asymptomatic and symptomatic groups did not differ in terms of gender distribution (P=0.76) and severity of stenosis (P=0.62). Echolucent plaques (type 1 and 2) were more predominant in patients with symptomatic disease (P=0.004, OR=2.13, 95% CI=1.26-3.6). Patients with plaques type 1 were relatively younger than those with type 4 (P=0.02). None of the other factors assessed had any significant association with symptomatic disease and any type of carotid plaque. CONCLUSION: Besides the severity of carotid stenosis, the presence of an echolucent plaque appears as an important factor associated with symptomatic ICA disease. Also young patients are more likely to have an echolucent plaque suggesting an age-related association with plaque maturation.

Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thrombo-embolism in high-risk patients.

BACKGROUND: It has been suggested that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thrombo-embolism (defined as deep vein thrombosis and pulmonary embolism, or both) in high-risk patients. OBJECTIVES: To assess the efficacy of intermittent pneumatic leg compression combined with pharmacological prophylaxis versus single modalities in preventing venous thrombo-embolism in high-risk patients. SEARCH STRATEGY: The Cochrane Peripheral Vascular Diseases (PVD) Group searched the reference lists of their Specialised Register (last searched 17 July 2007) and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched The Cochrane Library 2008, issue 3) for relevant articles to identify additional trials. SELECTION CRITERIA: Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) of combined intermittent pneumatic leg compression and pharmacological interventions used to prevent venous thrombo-embolism in high-risk patients. DATA COLLECTION AND ANALYSIS: Data extraction was undertaken independently by two review authors using data extraction sheets.

Association of plaque echostructure and cardiovascular risk factors with symptomatic carotid artery disease.

BACKGROUND: Severity of stenosis remains the main factor for assessing risk of stroke in patients with internal carotid artery (ICA) disease. This study was conducted to investigate the association of plaque echostructure and other established and emerging cardiovascular risk factors with symptomatic ICA disease. DESIGN: Cross-sectional study of consecutive patients with significant (> 50%) ICA stenosis. PATIENTS AND METHODS: Carotid plaque echostructure, smoking, hypertension, diabetes mellitus, serum lipoprotein (a), homocysteine, vitamin B12, folate, cholesterol to high-density lipoprotein ratio, triglycerides, C-reactive protein, and the Framingham risk score were assessed in 124 consecutive patients (70 asymptomatic; 54 symptomatic) with significant (> 50%) ICA stenosis. RESULTS: The asymptomatic and symptomatic groups did not differ in terms of gender distribution (p = 0.76) and severity of stenosis (p = 0.62). Echolucent plaques (type 1 and 2) were more predominant in patients with symptomatic disease (p = 0.004, OR = 2.13, 95% CI = 1.26-3.6). Patients with plaques type 1 were relatively younger than those with type 4 (p = 0.02). None of the other factors assessed had any significant association with symptomatic disease and any type of carotid plaque. CONCLUSIONS: Besides the severity of carotid stenosis, the presence of an echolucent plaque appears as an important factor associated with symptomatic ICA disease. Also, young patients are more likely to have an echolucent plaque suggesting an age-related association with plaque maturation.

Common femoral artery intima-media thickness as marker for cardiovascular disease in asymptomatic adults.

BACKGROUND: The common carotid intima-media thickness (IMT) is considered as a marker of cardiovascular disease, while the value of the common femoral IMT is not well defined. The aim of the present study was to investigate the value of common femoral IMT alone or in combination with the common carotid IMT as a marker of cardiovascular disease in asymptomatic adults. PATIENTS AND METHODS: Eighty-three individuals with no history of cardiovascular disease were subjected to IMT measurement of both common carotid and common femoral arteries with high-resolution ultrasonography. The Framingham Heart Study (FHS) risk score was calculated for each subject (according to gender) and was correlated with the carotid IMT, femoral IMT, and the combined IMT measured at both arterial sites. RESULTS: The carotid and femoral IMT separately and in combination were found to be correlated with the FHS risk score, calculated based on either the total cholesterol or low density lipoprotein plasma levels (carotid IMT: r = 0.28, p = 0.035, and r = 0.35, p = 0.007, respectively, femoral IMT: r = 0.38, p = 0.003, and r = 0.43, p = 0.001, respectively, carotid-femoral IMT: r = 0.37, p = 0.005, and r = 0.46, p = 0.0001, respectively). In addition, femoral IMT was found to be correlated with the carotid IMT (r = 0.41, p = 0.001). CONCLUSIONS: Common carotid and common femoral IMT showed similar correlation with the FHS risk score. Additionally, the combination of IMT from both arterial sites was found to have similar correlation with the FHS risk score to carotid IMT alone.

Comparison of three intermittent pneumatic compression systems in patients with varicose veins: a hemodynamic study.

AIM: Previous studies have demonstrated the hemodynamic impact of sequential leg compression, compared to uniform compression. The aim of this study was to compare the hemodynamic effectiveness of three compression devices: 1) circumferential sequential gradient compression (CSG); 2) a posterior uniform compression device (PU) and a posterior sequential rapid gradient inflation device (PSR). DESIGN OF THE STUDY: open, controlled trial. Thigh length sleeves were tested in 12 patients with primary bilateral varicose veins. INTERVENTIONS: the three devices were tested in the semirecumbent position. MAIN OUTCOME MEASURES: augmented flow velocity and volume flow, including the total and peak volume of blood expelled per hour during compression, were measured using duplex scanning. Refilling time was determined from velocity recordings of the common femoral vein. All values were expressed as median and interquartile range with P values obtained using the Mann-Whitney U-test. RESULTS: Compared to the median baseline flow, all three devices increased flow during compression by 2.5-3 times (P<0.0001). The cycles per hour for the three devices CSG, PSR and PU were 78 (70-88), 60 and 60, respectively; the duplex effective compression time was 11, 12 and 6 s, respectively; single cycle volume expelled during compression was 105, 85 and 45 mL (P<0.005), respectively; the total volume expelled per hour was 7 800, 5 200 (P<0.028) and 3 300 (P<0.005) mL/hr, respectively; peak velocity increased (P<0.001) from baseline of 12 cm/s to 38 cm/s for the CSG, 33 cm/s for the PU and to 68 cm/s for the PSR. CONCLUSION: The highest volume expelled per hour during compression was observed with the CSG and the lowest with the PSR. This was due to increased volume per cycle and more compression cycles over time, because of the CSG device's sensing of refill time. Although the peak velocity with the PSR was high, it was associated with reduced expelled volume, because of its short compression period. The PU occupied an intermediate position. The relative effectiveness of the three devices in deep vein thrombosis prevention should be tested in future studies.

Investigation of chronic venous insufficiency: A consensus statement (France, March 5-9, 1997).

This consensus document provides an up-to-date account of the various methods available for the investigation of chronic venous insufficiency of the lower limbs (CVI), with an outline of their history, usefulness, and limitations. CVI is characterized by symptoms or signs produced by venous hypertension as a result of structural or functional abnormalities of veins. The most frequent causes of CVI are primary abnormalities of the venous wall and the valves and secondary changes due to previous venous thrombosis that can lead to reflux, obstruction, or both. Because the history and clinical examination will not always indicate the nature and extent of the underlying abnormality (anatomic extent, pathology, and cause), a number of diagnostic investigations have been developed that can elucidate whether there is calf muscle pump dysfunction and determine the anatomic extent and severity of obstruction or reflux. The difficulty in deciding which investigations to use and how to interpret the results has stimulated the development of this consensus document. The aim of this document was to provide an account of these tests, with an outline of their usefulness and limitations and indications of which patients should be subjected to the tests and when and of what clinical decisions can be made. This document was written primarily for the clinician who would like to learn the latest approaches to the investigation of patients with CVI and the new applications that have emerged from recent research, as well as for the novice who is embarking on venous research. Care has been taken to indicate which methods have entered the clinical arena and which are mainly used for research. The foundation for this consensus document was laid by the faculty at a meeting held under the auspices of the American Venous Forum, the Cardiovascular Disease Educational and Research Trust, the European Society of Vascular Surgery, the International Angiology Scientific Activity Congress Organization, the International Union of Angiology, and the Union Internationale de Phlebologie at the Abbaye des Vaux de Cernay, France, on March 5 to 9, 1997. Subsequent input by co-opted faculty members and revisions in 1998 and 1999 have ensured a document that provides an up-to-date account of the various methods available for the investigation of CVI.

Comparison of two intermittent pneumatic compression systems. A hemodynamic study.

AIM: Sequential leg compression has been previously shown to be superior to uniform compression. The aim of our study was to compare the hemodynamic effectiveness of the portable sequential compression device (SCD Express Compression System, Tyco Healthcare Group LP, Mansfield, MA, USA) with a rapid inflation device (VenaFlow, Aircast, Inc, Summit, NJ, USA). The former, by sensing venous refill time, commences compression when the calf veins are refilled. METHODS: The two devices were tested in 12 normal volunteers in the semirecumbent position using duplex ultrasound. Baseline and augmented flow velocity and volume flow were measured at the level of the common femoral vein, above the saphenofemoral junction. Refilling time was determined from velocity recordings of the common femoral vein. Total and peak volume of blood expelled per hour during compression were calculated using flow data and the individual cycling rate. RESULTS: Both devices increased venous flow velocity, up to 3.8 times the baseline (all P<0.001). Refill time of the rapid inflation device was shorter in comparison with the sequential compression device (15+/-2.2 vs 25+/-4 s; P<0.001), suggesting incomplete vein evacuation. The sequential compression device, by augmenting flow throughout a significantly longer compression period per cycle (10.9 s vs 6.3 s), expelled significantly more venous blood (121+/-68 vs 81+/-63 mL; P<0.001). Similarly, the total volume of blood expelled per hour with the sequential compression device was 100% higher than the rapid inflation device (9685+/-5426 vs 4853+/-3658 mL; P<0.001). Although peak velocity enhancement was higher with the rapid inflation device, flow augmentation (a product of average blood flow velocity) was comparable (669+/-367 vs 771+/-574 cm/s; P=0.223) with the sequential compression device, mainly because the rapid inflation device failed to maintain flow enhancement beyond the initial flow surge. CONCLUSIONS: Sequential compression showed hemodynamic superiority compared to a rapid inflation device. This was enhanced further by the sensing of refill time, which resulted in more compression cycles over time. The relative efficacy of the two devices in deep vein thrombosis prevention should be tested in future studies.

Thrombophilia and venous thromboembolism. International consensus statement. Guidelines according to scientific evidence.

Thrombophilia is the term now used to describe predisposition to increased risk of venous and occasionally arterial thromboembolism due to hematological abnormalities. It can be a multifactorial disorder where congenital defects of anticoagulant or procoagulant factors may be combined with acquired hematological abnormalities. It should be considered in patients with a documented unexplained thrombotic episode or a positive family history. The aim of this document is to provide guidelines for investigation and management of patients with thrombophilia in the presence or absence of venous thromboembolism (VTE).

Chronic venous disease and the leukocyte-endothelium interaction: from symptoms to ulceration.

The mechanisms regulating varicose vein development and the subsequent skin sequelae seen in chronic venous disease (CVD) have been investigated recently. Despite the diversity of signs and symptoms associated with the disease, it seems likely that they are related to venous hypertension. Valvular incompetence is the most important cause of venous hypertension. Recent findings suggest that inflammatory processes are involved in the structural remodeling in venous valves and in the vein wall, leading to valvular incompetence and the development of varicose veins. This has been shown by Ono and colleagues, who found infiltration of valve leaflets and the venous wall by leukocytes (monocytes and tissue macrophages) in all valve specimens from patients with CVD and in none from controls. Further work by Takase and colleagues confirmed this hypothesis. Vein wall remodeling is likely to involve the complex interplay of a range of factors, including an altered ratio between metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), and elevated levels of cytokines and growth factors favor an alteration of the extracellular matrix. Neutrophils and mast cells and their interaction with the venous endothelium are believed to play an important role in the initiation of the inflammatory response in CVD. The transmission of high venous pressures to the dermal microcirculation results in the stimulation of an inflammatory process in which cytokine and growth factor release leads to leukocyte migration into the interstitium and the initiation of further inflammatory events. This process is associated with the intense dermal fibrosis and tissue remodeling seen in chronic venous insufficiency. The many manifestations of the disease are frequently associated with symptoms usually ascribed to CVD. The proportion of patients with symptoms increases with increasing CEAP clinical classes, but the mechanisms underlying symptom appearance have not been elucidated. It has been postulated that it is related to the inflammatory cascade of events seen at all stages of CVD and in which the leukocyte and its interaction with the endothelium play a key role. It is increasingly believed that the emerging twin themes of disturbed venous flow patterns and chronic inflammation underlie and link all the manifestations of the disease. Among the many pathophysiologic mechanisms at work, the leukocyte-endothelium interactions seem to be important in many aspects of the disease and have been identified as a possible target for pharmacologic intervention. Pharmacologic agents that could attenuate various elements of the inflammatory cascade and inhibit the inflammatory process might offer a greater opportunity to prevent future morbidity. It seems reasonable to speculate that such treatment could reduce the risk of CVD progression if applied as soon as the first symptoms appear.

Cardiovascular outcomes in type 2 diabetes. A double-blind placebo-controlled study of bezafibrate: the St. Mary's, Ealing, Northwick Park Diabetes Cardiovascular Disease Prevention (SENDCAP) Study.

OBJECTIVE: To determine whether serum lipid intervention, in addition to conventional diabetes treatment, could alter cardiovascular outcomes in type 2 diabetes. RESEARCH DESIGN AND METHODS: There were 164 type 2 diabetic subjects (117 men, 47 women) without a history of clinical cardiovascular disease randomized to receive either bezafibrate or placebo daily on a double-blind basis in addition to routine diabetes treatment and followed prospectively for a minimum of 3 years. Serial biochemical and noninvasive vascular assessments, carotid and femoral artery B-mode ultrasound measurements, and those pertaining to coronary heart disease (CHD)--clinical history, the World Health Organization (WHO) cardiovascular questionnaire, and resting and exercise electrocardiogram (ECG)--were recorded. RESULTS: Bezafibrate treatment was associated with significantly greater reductions over 3 years in median serum triglyceride (-32 vs. 4%, P = 0.001), total cholesterol (-7 vs. -0.3%, P = 0.004), and total-to-HDL cholesterol ratio (-12 vs. -0.0%, P = 0.001), and an increase in HDL cholesterol (6 vs. -2%, P = 0.02) as compared with placebo. There was a trend toward a greater reduction of fibrinogen (-18 vs. -6%, P = 0.08) at 3 years. No significant differences between the two groups were found in the progress of ultrasonically measured arterial disease. In those treated with bezafibrate, there was a significant reduction (P = 0.01, log-rank test) in the combined incidence of Minnesota-coded probable ischemic change on the resting ECG and of documented myocardial infarction. CONCLUSIONS: Improving dyslipidemia in type 2 diabetic subjects had no effect on the progress of ultrasonically measured arterial disease, although the lower rate of "definite CHD events" in the treated group suggests that this might result in a reduction in the incidence of coronary heart disease.

Descending phlebography in patients with venous ulceration: hemodynamic implications.

AIM: The aim of this paper is to report on the hemodynamic significance of the various degrees reflux as demonstrated on descending phlebography, by comparing the phlebographic findings with ambulatory venous pressure (AVP) measurements. METHOD: Thirty-two patients (45 affected limbs) with active or healed venous ulceration were admitted to the study. Descending phlebography with grading of reflux (0-4 using Herman's grading), AVP and refilling time 90 (RT90) were performed in all patients. In addition, the presence of deep to superficial reflux into the great saphenous vein at the sapheno-femoral junction, thigh incompetent perforating veins, small saphenous vein at the saphenopopliteal junction and incompetent calf perforating veins was recorded using ascending functional phlebography. The examined limbs were separated into two groups according to the Grade of reflux. Group I consisted of limbs in which popliteal valve incompetence was not demonstrated on descending phlebography, i.e., Grades 0-2 (18 limbs). Group II consisted of limbs with popliteal reflux as demonstrated by descending venography, i.e., grades 3 and 4 (27 limbs). RESULTS: In Group I the mean AVP ± SD was 47.2 ± 9.3 mmHg (range 31-67 mmHg). After the application of the ankle tourniquet to exclude the effects of the superficial venous incompetence on the pressure recordings, the mean AVP ± SD became 28.1 ± 9.9 mmHg (range 11-44) (paired t test: P < 0.001). In Group II (limbs with incompetent popliteal valves) the mean AVP ± SD was 71.6 ± 12.7 mmHg (range 49-95 mmHg) before the tourniquet. This was significantly higher than in Group I (t test: P < 0.001). The application of the ankle tourniquet in this group produced a small but significant decrease in the AVP (mean AVP ± SD: 66 ± 14.5 mmHg) (paired t test: P < 0.001). CONCLUSION: Incompetence of the femoral valves in the presence of competent popliteal valves adds very little to the hemodynamic abnormality produced by superficial venous reflux. In the majority of these patients, there is co-existing reflux from deep to superficial veins with associated superficial valve incompetence which is responsible for the venous hypertension, skin changes and ulceration. The hemodynamic changes which in the past had been associated with deep venous insufficiency (AVP >45 mmHg and RT90 < 14 seconds despite the application of an ankle tourniquet) occur only when there is popliteal incompetence.

Comparison between insulin resistance indices and carotid and femoral atherosclerosis: a cross-sectional population study.

AIM: The aim of this study was to investigate the association between commonly used insulin resistance (IR) indices and the presence and extent of carotid and femoral atherosclerosis in a general population setting. METHODS: Cross-sectional analysis of 762 volunteers from the ongoing epidemiological Cyprus Study (46.6% male; mean age=60.5±10.2). 1) Carotid intima-media thickness (IMTcc), 2) carotid and femoral atherosclerotic plaque presence, 3) total plaque area in the carotid/femoral bifurcations (sum of the largest plaques in each carotid/femoral bifurcation-SPAcar/fem), and 4) total plaque area in both carotid and femoral bifurcations (sum of the areas of the largest plaques present in each of the four bifurcations-SPA) were measured using ultrasound at baseline. The HOMA-IR, QUICKI and McAuley indices as well as fasting insulin levels were estimated and their quartiles were used in linear and logistic regression analysis. RESULTS: All IR indices studied were strongly associated with IMTcc (P<0.01for all) even after adjustment for age and sex and exclusion of diabetic subjects. However, when looking at plaque presence and size (i.e.area) only the HOMA-IR and especially the McAuley Index were associated with both carotid plaque presence (ORadj=1.17; 95%CI=1.01 to 1.36; P=0.03 and ORadj=0.86; 95%CI=0.74 to 0.99; P=0.04 respectively) and area (ORadj=0.10; 95%CI=0.008 to 0.20; P=0.03 and ORadj=-0.11; 95%CI=-0.20 to -0.009; P=0.03 respectively), after adjustment. The McAuley Index remained a significant predictor of both carotid plaque presence and area even after exclusion of diabetic subjects (P=0.04). CONCLUSION: Our results show that while all indices were associated with carotid IMT, supporting a strong role for IR in intimal-medial thickening, only the HOMA-IR and especially the McAuley Index were associated with both carotid plaque presence and area, after adjustment. This highlights the importance of including triglyceride levels in estimating the risk for atherosclerotic plaque in the carotids as well as the possible differences in determinants for atherosclerosis between arterial sites.

Reproducibility of computer-quantified carotid plaque echogenicity: can we overcome the subjectivity?

BACKGROUND AND PURPOSE: We sought to assess the reproducibility, interobserver variability, and application to clinical studies of a new method for the quantitative assessment of carotid plaque echogenicity. METHODS: Carotid plaques were scanned with the use of ultrasound, and their images were stored in a computer. They were normalized by assigning certain gray values to blood and adventitia, and the gray scale median (GSM) was used to quantify their echogenicity. The variability between storage media, between degrees of magnification, and between probes was assessed. The method was applied to 232 asymptomatic carotid plaques causing 60% to 99% stenosis in relation to the presence of ipsilateral CT-demonstrated brain infarcts. In all parts of the study the plaque GSM was measured before and after normalization to evaluate its effect. Interobserver agreement for the scanning process was assessed. RESULTS: The GSM mean difference before and after normalization for variability studies of storage media, degrees of magnification, and probes was -14.5 and -0.12, 2.24 and 1.68, and -8.3 and -0.7, respectively. The median GSM of plaques associated with ipsilateral nonlacunar silent CT-demonstrated brain infarcts was 14, and that of plaques that were not so associated was 30 (P:=0.003). The interobserver GSM difference was -0.05 (95% CI, -1.7 to 1.6). CONCLUSIONS: Our method decreases the variability between storage media and between probes but not the variability between degrees of magnification. It separates echomorphologically the carotid plaques associated with silent nonlacunar CT-demonstrated brain infarcts from plaques that are not so associated.

Femoral atherosclerosis in an older British population: prevalence and risk factors.

Most estimates of the prevalence of peripheral atherosclerosis have been based on intermittent claudication or lower limb blood flow. The aim of this study was therefore to determine the prevalence of underlying femoral plaque, and to determine its association with other cardiovascular disease and risk factors. Presence of plaque was identified using ultrasound in a random sample of men (n=417) and women (n=367) aged 56-77 years. Coexistent cardiovascular disease, exercise and smoking were determined by questionnaire, blood pressure was recorded, and serum cholesterol and plasma fibrinogen were determined. Of the 784 subjects that were scanned, 502 (64%) demonstrated atherosclerotic plaque. Disease prevalence increased significantly with age (P<0.0001), and was more common in men (67.1 vs. 59.4%, P<0.05). Subjects with femoral plaque had a significantly greater odds of previous ischaemic heart disease (OR 2. 2, 95% CI 1.3, 3.7) and angina (OR 1.7, 95% CI 1.03, 2.7), but not of stroke or leg pain on exercise. Current and ex-smoking, raised serum total cholesterol and plasma fibrinogen levels, but not blood pressure, were associated with an increased risk of femoral plaque, independent of age and sex. Frequent exercise and a high HDL cholesterol were significantly associated with lower risk. In conclusion, therefore, atherosclerotic disease of the femoral artery affects almost two-thirds of the population in late middle age. It is associated with an increased prevalence of ischaemic heart disease and angina, but whether detecting at risk individuals using ultrasound offers advantages over simpler and less expensive risk factor scoring requires evaluation in trials.