Effects of semaglutide on functional capacity in patients with type 2 diabetes and peripheral arterial disease: rationale and design of the STRIDE trial

Background/Introduction

Lower extremity peripheral arterial disease (PAD) is a severe form of atherosclerotic cardiovascular (CV) disease. The classical symptom is intermittent claudication (IC), associated with limited walking ability and poor health-related quality of life (QoL). Type 2 diabetes (T2D) is one of the leading causes of PAD; ∼30% of patients with PAD have T2D. While anti-atherosclerotic drugs and lifestyle changes are recommended, there are no effective drugs to specifically improve functional outcomes in PAD and T2D. Semaglutide is a glucagon-like peptide-1 receptor agonist (GLP-1RA) approved as an adjunct to diet and exercise for glycaemic control in patients with T2D. In the T2D SUSTAIN clinical trial programme, once-weekly (OW) subcutaneous semaglutide 0.5 and 1.0 mg was superior for glycaemic control and weight loss vs placebo and a range of approved antidiabetic drugs. In SUSTAIN 6, a dedicated CV outcomes trial, OW semaglutide resulted in a 26% reduction in three-point major adverse CV events (MACE) compared with placebo in patients with T2D at high CV risk, leading to its approval for MACE risk reduction in those with T2D and CV disease in the USA. Evidence suggests this may be partly attributable to the anti-inflammatory and anti-atherosclerotic effects of semaglutide, which may also apply to PAD.

Purpose

The STRIDE trial will demonstrate the effect of OW semaglutide 1.0 mg vs placebo on walking ability in patients with T2D and PAD with IC.

Methods

STRIDE is a 52-week, randomised, double-blind, placebo-controlled, phase 3b trial. Trial design and eligibility criteria are shown in the Figure; ∼800 patients will be randomised 1:1 to OW semaglutide 1.0 mg or placebo, both added to standard of care. The primary endpoint is change in maximum walking distance on a constant load treadmill test from baseline to week 52. Secondary confirmatory endpoints include changes in pain-free walking distance and PAD-specific, health-related patient-reported outcomes (Vascular QoL Questionnaire-6) from baseline to week 52.

Results

The trial started in October 2020 and is currently recruiting, with ∼120 sites in ∼20 countries across Asia, Europe, and North America.

Conclusion

STRIDE is the first and only dedicated PAD outcomes trial with a GLP-1RA and thus presents a unique trial design. While major adverse limb events typically occur in the later stages of PAD, STRIDE instead measures the effect of OW semaglutide on functional outcomes such as walking ability and QoL, which affect everyday living in patients with PAD and IC. STRIDE data will provide important clinical insights regarding the role of OW semaglutide in patients with T2D and PAD.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Novo Nordisk A/S

Plasma levels of β2-microglobulin are associated with atherosclerosis in patients with systemic lupus erythematosus: a cross-sectional cohort study

Objective The objective of this paper is to examine the association between plasma levels of β2-microglobulin (β2MG), a protein previously associated with atherosclerosis, and the presence of carotid plaque (CP) or coronary artery calcium (CAC) in a cross-sectional cohort study of patients with systemic lupus erythematosus (SLE). Methods Patients with SLE were enrolled between June 2013 and May 2014. The presence of CP and CAC was assessed with ultrasonography and computed tomography scan, respectively. The presence of CP or CAC in the SLE patients was analyzed with respect to plasma levels of β2MG and renal function expressed as the estimated glomerular filtration rate (eGFR). Results The study cohort consisted of 147 patients, 89% women and 95% Caucasians. The median age was 46 (range: 21-75) years with a median disease duration of 14 years. CP and CAC was observed in 29 (20%) and 57 (39%) of patients, respectively. CP or CAC was seen in 62 (42%) patients and was associated with the highest quartile of plasma β2MG in patients with eGFR ≥ 90 ml/min/1.73 m²; OR = 18 (95% CI: 1.7-181). β2MG adjusted for eGFR was also associated with presence of CP or CAC in the total cohort. The exclusion of 25 patients with a prior history of cardiovascular disease did not change the observed associations. Conclusion In this study, we found significant associations between imaging markers of atherosclerosis and high plasma levels of plasma β2MG. These data suggest that β2MG is a candidate for further study as a biomarker for atherosclerosis in SLE.

Administration of platelets to ruptured abdominal aortic aneurysm patients before open surgery: a prospective, single-blinded, randomised study

BACKGROUND

In patients undergoing open surgery for a ruptured abdominal aortic aneurysm (rAAA), survivors demonstrate a high platelet count, and proactive administration of platelets (and fresh frozen plasma) appears to influence mortality.

OBJECTIVES

This trial investigated the effect of platelets administered before transport to surgery.

METHODS

In a prospective study design, patients were randomised to receive platelets (intervention; n = 61) or no platelets (control; n = 61) before transport to vascular surgery from 11 local hospitals. The study was terminated when one of the vascular surgical centres implemented endovascular repair for rAAA patients.

RESULTS

Thirty days after surgery, mortality was 36% for patients with intervention vs 31% for controls (P = 0·32). Post-operative thrombotic events (14 vs 15; P = 0·69), renal failure (11 vs 10; P = 0·15) and pulmonary insufficiency (34 vs 39; P = 0·15) were similar in the two groups of patients. No adverse reactions to platelet administration were observed. In addition, length of stay in the intensive care unit was unaffected by intervention.

CONCLUSIONS

For patients planned for open repair of a rAAA, we observed no significant effect of early administration of platelets with regard to post-operative complications and stay in the ICU or in hospital and also no significant effect on mortality.

Three-year follow-up of implementation of evidence-based transfusion practice in a tertiary hospital

BACKGROUND AND OBJECTIVES

Traditionally, Denmark has had a high rate of allogeneic red blood cell transfusion caused by a liberal transfusion practice despite the existence of restrictive guidelines. We established a Patient Blood Management programme in a tertiary hospital and report the results of the implementation of evidence-based transfusion practice.

MATERIALS AND METHODS

Red blood cell transfusion quality indicators were compared with the evidence-based guideline at hospital and department level. Based on this evaluation, wards were selected for interventions targeting doctors and nurses. The implementation process was monitored by transfusion quality and utilization data over a 3-year period with totally 166 341 admissions in 98 960 mixed, adult medical and surgical patients.

RESULTS

At the hospital level, transfusion above the upper guideline limit decreased from 23 to 10% (P < 0·001), and transfusion at or below the restrictive haemoglobin trigger of 7·3 g/dl increased from 7 to 19% (P < 0·001). The percentage of single-unit transfusions increased from 72 to 78% (P < 0·001), and the majority of transfusion rates and volumes decreased significantly. Red cell use decreased with 41% in surgical procedures and 28% in admissions (P < 0·001).

CONCLUSION

The intervention was associated with a significant and sustained overall increase in compliance with national guidelines for red blood cell transfusion for non-bleeding patients, and led to significantly fewer patients being exposed to transfusion.

Randomized clinical trial of mast cell inhibition in patients with a medium-sized abdominal aortic aneurysm

Background

Abdominal aortic aneurysm (AAA) is thought to develop as a result of inflammatory processes in the aortic wall. In particular, mast cells are believed to play a central role. The AORTA trial was undertaken to investigate whether the mast cell inhibitor, pemirolast, could retard the growth of medium-sized AAAs. In preclinical and clinical trials, pemirolast has been shown to inhibit antigen-induced allergic reactions.

Methods

Inclusion criteria for the trial were patients with an AAA of 39–49 mm in diameter on ultrasound imaging. Among exclusion criteria were previous aortic surgery, diabetes mellitus, and severe concomitant disease with a life expectancy of less than 2 years. Included patients were treated with 10, 25 or 40 mg pemirolast, or matching placebo for 52 weeks. The primary endpoint was change in aortic diameter as measured from leading edge adventitia at the anterior wall to leading edge adventitia at the posterior wall in systole. All ultrasound scans were read in a central imaging laboratory.

Results

Some 326 patients (mean age 70·8 years; 88·0 per cent men) were included in the trial. The overall mean growth rate was 2·42 mm during the 12-month study. There was no statistically significant difference in growth between patients receiving placebo and those in the three dose groups of pemirolast. Similarly, there were no differences in adverse events.

Conclusion

Treatment with pemirolast did not retard the growth of medium-sized AAAs. Registration number: NCT01354184 (https://www.clinicaltrials.gov).

Three-dimensional ultrasound evaluation of small asymptomatic abdominal aortic aneurysms

OBJECTIVE

Non-invasive and reproducible size measurements that correlate well with computed tomography (CT) are desirable in the management of small abdominal aortic aneurysms (AAA). Three dimensional ultrasound (3D-US) technology may reduce inaccuracy because of variations in orientation of the image planes and axis. This study aimed to determine any differences in paired size estimation associated with three 3D-US derived methods using 3D-CT as the gold standard. When CTA was not available, the patients were enrolled anyway to assess 3D-US reproducibility in terms of agreement between two physicians.

METHODS

In the period from 1 March 2013 to 27 February 2014, consecutive patients with a small AAA, <5.5 cm for men and <5.2 cm for women, underwent 3D-US examination and three AAA size measures were obtained: dual plane diameter, diameter perpendicular to the residual sac's centreline and a partial volume.

RESULT

In all, 122 consecutive US examinations were performed. Patients were excluded because of inadequate AAA size (n = 11) and for technical reasons (n = 11). Thus, 100 patients (F/M; 20/80) with a median maximum AAA diameter of 46 (range 31-55) mm were analysed. The mean US dual plane diameter and the 3D-US centreline diameter were 2.6 mm and 1.8 mm smaller than the mean 3D-CT centreline diameter, respectively (p = .003). The inter-observer reproducibility coefficient was 3.7 mm for the US dual plane diameter and 3.2 mm for the 3D-US centreline diameter (p = 0.222). For the partial volume, the reproducibility was 8-12%, corresponding to a diameter variability of ±3 mm. The median time used for post-processing of the 3D-US acquisition was 72 (range 46-108) seconds per examination.

CONCLUSION

3D-US demonstrated an acceptable reproducibility and a good agreement with 3D-CT, and has the potential to improve future AAA management through more reliable ultrasound guided size estimates.

Chronic cerebrospinal venous insufficiency and venous stenoses in multiple sclerosis

OBJECTIVES

The traditional view that multiple sclerosis (MS) is an autoimmune disease has recently been challenged by the claim that MS is caused by chronic cerebrospinal venous insufficiency (CCSVI). Although several studies have questioned this vascular theory, the CCSVI controversy is still ongoing. Our aim was to assess the prevalence of CCSVI in Danish MS patients using sonography and compare these findings with MRI measures of venous flow and morphology.

METHODS

We investigated cervical and cerebral veins in 24 patients with relapsing-remitting MS (RRMS) and 15 healthy controls, using extracranial high-resolution ultrasound colour Doppler (US-CD) and transcranial colour Doppler sonography (TCDS), as well as magnetic resonance imaging (MRI) and phase-contrast MR blood flow measurements (PC-MR) of the cervical veins.

RESULTS

US-CD could not identify the left internal jugular vein (IJV) in one MS patient, other ultrasound examinations were normal in patients with MS. There was no difference in mean cross-sectional area of the IJV in MS patients compared with controls. Only one patient with MS and two healthy controls fulfilled one CCSVI criterion, and none fulfilled more than one CCSVI criterion. MR venography showed insignificant IJV stenosis (1-49%) in two patients with MS, whereas 50-69% IJV stenosis was detected in two healthy controls. There was no difference in PC-MR measurements of mean IJV blood flow between patients with MS and controls.

CONCLUSION

Our results do not corroborate the presence of vascular pathology in RRMS and we found no evidence supporting the CCSVI hypothesis.

Observer agreement of lower limb venous reflux assessed by duplex ultrasound scanning using manual and pneumatic cuff compression in patients with chronic venous disease and controls

OBJECTIVES

The study aimed to evaluate observer agreement between two experienced ultrasound operators examining deep venous reflux assessed by duplex ultrasound (DU) using either manual or pneumatic cuff compression. In addition, the two methods were compared with each other with regard to immediate "eyeballing" and direct measurements of reflux time from Doppler flow curves.

DESIGN

This was a case control study.

MATERIAL AND METHODS

Cases were found among patients admitted to our department with deep venous thrombosis of the iliac, femoral or popliteal veins during the period 1999-2006. Controls were departmental staff. DU was used to assess valve function in the common femoral, femoral and popliteal veins in the standing position using manual and pneumatic cuff compression. The investigators were blinded to the other's observations. Observer agreement was assessed using the Rasch model for binary items.

RESULTS

Twenty patients and 20 controls participated in the study and were analysed by the Rasch model. Quantitative measurement was found to be more reliable than "eyeballing", and cuff compression was more reproducible in identifying reflux than manual compression. We found that assessment by manual measurement by one investigator functioned at a lower level of expertise than for the other investigator.

CONCLUSIONS

Cuff measurements were more accurate in diagnosing deep venous reflux than manual measurements, and measurement was more accurate than "eyeballing". The fact that assessment by manual compression by one investigator functioned at a lower level of expertise suggests that cuff measurement might be the optimal assessment method, especially in the difficult cases.

Comparison of ankle-brachial index measured by an automated oscillometric apparatus with that by standard Doppler technique in vascular patients

OBJECTIVES

To evaluate the determination of ankle-brachial indices (ABIs) using a simple automated ankle pressure measurement device in comparison with the Doppler technique.

DESIGN

ABI was measured in 61 patients (122 legs) admitted to the department of vascular surgery, Rigshospitalet. ABI was calculated twice using both the methods on both legs.

MATERIALS AND METHODS

We tested the automated oscillometric blood pressure device, CASMED 740, for measuring ankle and arm blood pressure and compared it with the current gold standard, the hand-held Doppler technique, by the Bland-Altman analysis.

RESULTS

Using the Doppler-derived ABI as the gold standard, the sensitivity and specificity of the oscillometric method for determining an ABI<or=0.9 is 71% and 92%, respectively. The overall accuracy for correctly identifying an ABI of 0.9 with the oscillometric method was 82%. Ankle pressures measured by CASMED 740 were systematically higher in patients with reduced ankle pressures, but accurate in patients with ankle pressures above 90 mm Hg.

CONCLUSION

Automated oscillometric assessment of ankle blood pressure and ABI may falsely categorise PAD patients as having a normal ankle pressure and ABI.

Hemorrhagic stroke in the Stroke Prevention by Aggressive Reduction in Cholesterol Levels study

BACKGROUND

In the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study, atorvastatin 80 mg/day reduced the risk of stroke in patients with recent stroke or TIA. Post hoc analysis found this overall benefit included an increase in the numbers of treated patients having hemorrhagic stroke (n = 55 for active treatment vs n = 33 for placebo).

METHODS

We explored the relationships between hemorrhage risk and treatment, baseline patient characteristics, most recent blood pressure, and most recent low-density lipoprotein (LDL) cholesterol levels prior to the hemorrhage.

RESULTS

Of 4,731 patients, 67% had ischemic strokes, 31% TIAs, and 2% hemorrhagic strokes as entry events. In addition to atorvastatin treatment (HR 1.68, 95% CI 1.09 to 2.59, p = 0.02), Cox multivariable regression including baseline variables significant in univariable analyses showed that hemorrhagic stroke risk was higher in those having a hemorrhagic stroke as the entry event (HR 5.65, 95% CI 2.82 to 11.30, p < 0.001), in men (HR 1.79, 95% CI 1.13 to 2.84, p = 0.01), and with age (10 y increments, HR 1.42, 95% CI 1.16 to 1.74, p = 0.001). There were no statistical interactions between these factors and treatment. Multivariable analyses also found that having Stage 2 (JNC-7) hypertension at the last study visit before a hemorrhagic stroke increased risk (HR 6.19, 95% CI 1.47 to 26.11, p = 0.01), but there was no effect of most recent LDL-cholesterol level in those treated with atorvastatin.

CONCLUSIONS

Hemorrhagic stroke was more frequent in those treated with atorvastatin, in those with a hemorrhagic stroke as an entry event, in men, and increased with age. Those with Stage 2 hypertension at the last visit prior to the hemorrhagic stroke were also at increased risk. Treatment did not disproportionately affect the hemorrhagic stroke risk associated with these other factors. There were no relationships between hemorrhage risk and baseline low-density lipoprotein (LDL) cholesterol level or recent LDL cholesterol level in treated patients.

Hereditary hemochromatosis genotypes and risk of ischemic stroke

OBJECTIVE

We tested the hypothesis that the HFE genotypes H63D/H63D, H63D/wild type, C282Y/H63D, C282Y/C282Y, and C282Y/wild type are risk factors for symptomatic carotid atherosclerosis, ischemic cerebrovascular disease (ICVD), and ischemic stroke.

METHODS

We performed an age- and gender-matched case-control study of 701 cases with symptomatic carotid atherosclerosis vs 2,777 controls, and a prospective study of 9,178 individuals from the Danish general population followed for 24 years, during which 504 developed ICVD, of whom 393 had ischemic stroke.

RESULTS

Genotype was not consistently associated with symptomatic carotid atherosclerosis. The cumulative incidences of ICVD and ischemic stroke by age were increased for H63D/H63D vs wild type/wild type (log-rank: p = 0.003 and p < 0.001). H63D/H63D vs wild type/wild type had an age- and multifactorially adjusted hazard ratio of 2.0 (95% CI: 1.2 to 3.2; p = 0.007) and 2.1 (1.3 to 3.5; p = 0.004) for ICVD and of 2.4 (1.4 to 4.0; p = 0.001) and 2.8 (1.7 to 4.6; p < 0.001) for ischemic stroke; these remained significant after correction for multiple comparisons. Other hereditary hemochromatosis genotypes were not associated with ICVD or ischemic stroke.

CONCLUSIONS

Hereditary hemochromatosis H63D homozygosity predicts a two- to threefold risk of ICVD and ischemic stroke.

Organising a Nurse-driven PAD Rehabilitation Clinic Within the Vascular Surgical Department: What is Required and are Treatment Goals Reached – A Prospective Study?

OBJECTIVES

Patients with PAD may have severe symptoms from their lower extremities as well as a 3-4 fold increased risk of death due to systemic atherosclerosis. The purpose of this study was to identify whether treatment goals of a nurse led rehabilitation clinic were achieved.

DESIGN

Prospective cohort study over 4 year period to May 2004.

METHODS

All patients with symptomatic PAD were offered enrollment in a nurse-led rehabilitation clinic and given advice on diet and exercise. All smokers were offered smoking cessation advice and treatment. Anti-platelet therapy was prescribed to all patients and statin therapy was prescribed to those with dyslipidemia.

RESULTS

693 patients with symptomatic PAD were prospectively entered into the clinic (total 2563 clinic visits). Average age was 67 years and 53% were males. Some (167, 24%) were included for non-surgical treatment and most (526, 76%) were included as part of their postoperative follow-up. After 6 months, the proportion of patients taking platelet inhibitors and statins had increased from 63% and 27% to 87% and 84% respectively. Mean total cholesterol was reduced from 6.2 mmol/l to 4.9 mmol/l and mean LDL cholesterol from 3.9 mmol/l to 2.6 mmol/l. After 1 year the proportion of smokers was reduced from 59% to 51.5% (12.5% relative reduction).

CONCLUSION

This nurse-driven rehabilitation clinic has proven effective in reaching medication targets for secondary prevention. Smoking cessation was less successful.

Catheter Directed Thrombolysis for Treatment of Ilio-femoral Deep Venous Thrombosis is Durable, Preserves Venous Valve Function and May Prevent Chronic Venous Insufficiency

OBJECTIVES

To investigate the results of catheter directed thrombolysis offered to patients with acute femoro-iliac deep venous thrombosis (DVT).

DESIGN

Retrospective analysis of all patients treated with this modality at Gentofte Hospital until December 2003.

MATERIAL

Forty-five consecutive patients treated between June 1999 and December 2003 with a median age of 31 years. All patients had femoro-iliac DVT with an average anamnesis of 6 days.

METHODS

All patients were treated by catheter directed infusion of alteplase into the popliteal vein. After thrombolysis residual venous stenoses were treated by percutaneous balloon angioplasty (PTA) and stenting. Patients were followed with color-duplex scanning for assessment of venous patency and reflux.

RESULTS

Forty-two of 45 (93%) of cases were treated successfully with reopening of the thrombosed vein segments. In 30 of 45 cases a residual stenosis was treated by PTA and stenting. Only one serious complication was observed: Compartment syndrome of the forearm where arterial punctures had been taken. After an average of 24 months follow-up were no cases of re-thrombosis among the 42 patients discharged with open veins. Only two of 41 with presumed normal venous valve function prior to DVT developed reflux during follow-up.

CONCLUSION

In this selected patient group, catheter directed thrombolysis seems effective in treating acute DVT, it appears durable and preserves venous valve function in the majority. The method needs to be tested in a randomised controlled trial.

A method to create reference maps for evaluation of ultrasound images of carotid atherosclerotic plaque

Ten formalin-fixed atherosclerotic carotid plaques removed by endarterectomy were molded into rectangular agar blocks containing fiducial markers on the top surface. Plaque and fiducial markers were imaged with 3-D multiangle ultrasound (US) spatial compounding as well as planar X ray. Subsequently, the blocks were decalcified, sliced, photographed and analyzed histologically. This gave a total of 123 slices. The plaque regions of the photographs were outlined and the outline adjusted to partly compensate for occasional displacement during slicing. Inside this outline, the material constitutions were found by incorporating the histologic information. From this set, slices with 1. too much tissue displacement due to cutting or 2. lack of identification of calcification as found by x ray, were removed. This resulted in 53 reference maps. The material types identified covered soft tissues, fibrous tissue, calcified tissue and unidentified tissues. The 53 reference maps can be used for direct automated quantitative comparison with US images.

Fibrinogen predicts ischaemic stroke and advanced atherosclerosis but not echolucent, rupture-prone carotid plaques: the Copenhagen City Heart Study

AIMS

Whether the association between fibrinogen and cardiovascular events reflects an association with advanced atherosclerosis in general, or rupture-prone plaques in particular, is unclear. We examined whether fibrinogen predicts incidence of ischaemic stroke, advanced atherosclerosis (measured as carotid artery stenosis) and/or echolucent, rupture-prone plaques.

METHODS AND RESULTS

Study 1-8755 Copenhagen City Heart Study stroke-free participants; we observed 235 ischaemic strokes during 6 years of follow-up. Study 2-318 carotid stenosis patients and 1584 age- and gender-matched controls. Study 3-159 patients with echolucent vs 159 patients with echo-rich carotid artery plaques. Fibrinogen above vs below the median value of 3 g l(-1)predicted risk of ischaemic stroke (relative risk: 1.9; 95% CI: 1.4-2.5; 235 events). Significant risk was found in men (2.7; 1.7-4.2; 113 events) and with a similar trend in women (1.4; 0.9-2.0; 122 events), in young (5.2; 1.1-26; eight events) and middle aged (2.9; 1.6-5.4; 64 events) with a similar trend in the elderly (1.4; 1.0-2.0; 163 events). Fibrinogen levels in those with and without ischaemic stroke were 3.6 and 3.1 g l(-1)(ANCOVA: P<0.0001). Likewise, in those with and without carotid artery stenosis fibrinogen levels were 4.7 and 3.1 g l(-1)(P<0.0001); equivalent values for high-sensitive C-reactive protein were 3.6 and 1.4 mg l(-1)(P<0.0001). Finally, neither fibrinogen nor high-sensitive C-reactive protein levels differed between those with echolucent and echo-rich carotid artery plaques (P=0.61 and P=0.28); the power to exclude a 15% increase in fibrinogen or a 50% increase in high-sensitive C-reactive protein was 98 and 54%, respectively.

CONCLUSIONS

Elevated fibrinogen predicts future ischaemic strokes, particularly in men and in the young and middle aged. This is most likely a reflection of advanced atherosclerosis, rather than an association with rupture-prone plaques.

Real-time spatial compound imaging improves reproducibility in the evaluation of atherosclerotic carotid plaques

Compound imaging has the ability of reducing speckle and clutter artifacts demonstrated in in vitro studies compared to conventional, single-angle imaging. We investigated intra- and interobserver agreement of 38 outlines of carotid artery plaque images acquired by these techniques, by measuring the overlapping area after repeated outlines. In general, both techniques showed good agreement. When considering the images with poorest overlap, compound imaging had a significant advantage over conventional imaging regarding both intra- and interobserver agreement. The interobserver variation for the overlapping area after two outlines was 20% for conventional technique and 10% for compound. The interobserver variation of the gray scale median value (GSM) for conventional technique ranged from -32 to +20 and from -6 to +6 for compound. Likewise, the coefficient of repeatability for the GSM value was 13 for conventional imaging and three for compound imaging, and interobserver variation for the GSM value for the overlapping area was 34% and 9% for conventional and compound technique. In conclusion, compound imaging improves intra- and interobserver agreement and reduces interobserver variation in the GSM value in a clinical setting.

Ultrasonic echolucent carotid plaques predict future strokes

BACKGROUND

We tested prospectively the hypothesis that stroke development can be predicted by echolucency of carotid atherosclerotic plaques in previously symptomatic and asymptomatic patients.

METHODS AND RESULTS

We followed incidence of ipsilateral ischemic strokes for 4.4 years in 111 asymptomatic and 135 symptomatic patients with >/=50% relevant carotid artery stenosis. At inclusion, echogenicity of carotid plaques and degree of stenosis were evaluated with high-resolution B-mode ultrasound with computer-assisted image processing and Doppler ultrasound, respectively. We observed 44 ipsilateral ischemic strokes. In symptomatic patients, relative risk of ipsilateral ischemic stroke for echolucent versus echorich plaques was 3.1 (95% CI, 1.3 to 7.3), whereas for 80% to 99% versus 50% to 79% stenosis, the relative risk was 1.4 (95% CI, 0.7 to 3.0). Relative to symptomatic patients with echorich 50% to 79% stenotic plaques, those with echorich 80% to 99% stenotic plaques, echolucent 50% to 79% stenotic plaques, and echolucent 80% to 99% stenotic plaques had relative risks of ipsilateral ischemic strokes of 3.1 (95%CI, 0.7 to 14), 4.2 (95% CI, 1.2 to 15), and 7.9 (95% CI, 2.1 to 30), equivalent to absolute risk increases of 11%, 18%, and 28%. This was not observed in previously asymptomatic patients.

CONCLUSIONS

Echolucent plaques causing >/=50% diameter stenosis by Doppler ultrasound are associated with risk of future stroke in symptomatic but not asymptomatic individuals. This suggests that measurement of echolucency, together with degree of stenosis, may improve selection of patients for carotid endarterectomy.

Spiral computed tomographic imaging related to computerized ultrasonographic images of carotid plaque morphology and histology

OBJECTIVE

Echolucency of carotid atherosclerotic plaques, as evaluated by computerized B-mode ultrasonographic images, has been associated with an increased incidence of brain infarcts on cerebral computed tomographic scans. We tested the hypotheses that characterization of carotid plaques on spiral computed tomographic images correlates with that on computerized B-mode ultrasonographic images and that spiral computed tomographic imaging predicts the histomorphometric plaque content.

METHODS

The study included 38 patients with neurologic symptoms and at least 50% stenosis of the ipsilateral carotid artery. High-resolution B-mode ultrasonographic images and spiral computed tomographic images of carotid plaques were computer processed to yield a quantitative measure, the gray scale level of the plaque.

RESULTS

The mean Hounsfield value for spiral computed tomographic images correlated with the gray scale median for B-mode ultrasonographic images (univariate linear regression analysis: r = 0.45; P = .01) and the histologic content of calcification in the plaque (r = 0.34; P = .04) but not with lipid, hemorrhage, or fibrous tissue in the plaque.

CONCLUSIONS

Spiral computed tomographic imaging seems to correlate with B-mode ultrasonographic imaging for showing plaque characteristics. Spiral computed tomographic attenuation was also correlated with the amount of calcification noted on histologic examination but not with lipid and hemorrhage, the components thought to characterize vulnerable, rupture-prone plaques.

Increased Acute Phase Reactants are Associated with Levels of Lipoproteins and Increased Carotid Plaque Volume

OBJECTIVES

to test the hypotheses that increased acute phase reactants predict elevated levels of lipoproteins and increased plaque volume as well as echolucency of carotid plaques.

MATERIALS AND METHODS

the study included 258 patients with >or =50% carotid artery stenosis. Acute phase reactants (orosomucoid, C-reactive protein (CRP)) were measured in the fasting state, and ultracentrifugated lipoproteins before and after a standardised fat load test. Echogenicity of carotid plaques was detected using high-resolution B-mode ultrasound and computer-assisted image processing. A subgroup of 81 patients underwent carotid endarterectomy.

RESULTS

on linear regression analysis orosomucoid levels were positively associated with fasting and postprandial levels of all triglyceride-rich lipoproteins, and negatively associated with HDL cholesterol (p -values <0.0001); results for CRP were less pronounced. Orosomucoid and CRP both predicted the presence of an increased carotid plaque volume on univariate analysis (p =0.01 and p =0.02). Finally, orosomucoid was negatively associated with echolucency of carotid plaques ( p =0.05).

CONCLUSIONS

elevated levels of acute phase reactants are strongly associated with elevated levels of triglyceride-rich lipoproteins, increased plaque volume, and borderline significantly associated with echolucency of carotid plaques. Elevated acute phase reactants possibly predict severity of atherosclerosis, and presence of lipid-rich, rupture-prone plaques.

The lack of cardiovascular risk factor management in patients with critical limb ischaemia

AIM

to define the level of management of cardiovascular risk factors in patients treated for critical limb ischaemia in a vascular surgical setting.

MATERIALS AND METHODS

retrospective review of all (n =147) patients operated on for critical lower extremity ischaemia in 1998. We included pre- and postoperative cardiac events.

RESULTS

only eight (5%) (95% CI; 2-9) were on lipid lowering treatment and 58 (39%) (95% CI; 31-47) using acetylsalicylic acid.

CONCLUSIONS

only a minority of patients operated on for CLI were receiving adequate cardiovascular risk factor modification.

In vitro spatial compound scanning for improved visualization of atherosclerosis

A new off-line multiangle ultrasound (US) compound scanner has been built with the purpose of investigating possible improvements in visualization of vascular structure. Images of two formalin-fixed human atherosclerotic plaques removed by carotid endarterectomy were recorded from seven insonification angles over a range of 42 degrees and the individual images were combined (averaged) into a single image (spatial compounding). Compared to conventional B-mode imaging, this multiangle compound imaging (MACI) method features images with reduced angle-dependence, reduced random variation (speckle) and improved delineation of the plaque outline. With the MACI approach, it is, thus, easier to assess e.g., a possible residual lumen of an atherosclerotic artery as well as the level of echogenicity for the different plaque constituents.

A common mutation in lipoprotein lipase confers a 2-fold increase in risk of ischemic cerebrovascular disease in women but not in men

BACKGROUND

We previously showed that the common Asn291Ser substitution in lipoprotein lipase is associated with elevated plasma triglyceride levels and a 2-fold increase in the risk of ischemic heart disease in women but not men. In this study, we tested the hypothesis that this substitution is also associated with an increased risk of ischemic cerebrovascular disease (ICVD).

METHODS AND RESULTS

We compared 260 patients who had nonfatal ICVD and carotid stenosis >/=50% with 1560 age-matched controls and also compared 205 Copenhagen City Heart Study cases who had nonfatal ICVD with 1210 age-matched controls. All subjects were white and from Denmark. Overall, no significant difference was observed between carrier frequencies among those with and without ICVD; however, sex interacted with genotype in predicting ICVD in the ICVD and carotid stenosis cases (P=0.02). In Copenhagen City Heart Study cases, sex was not significant (P=0.18). Odds ratios for ICVD in female mutation carriers were 2.9 (95% confidence interval [CI], 1.3 to 6. 4) and 1.9 (95% CI, 0.8 to 4.6) in ICVD plus carotid stenosis cases and Copenhagen City Heart Study cases, respectively. Equivalent values in male mutation carriers were 0.8 (95% CI, 0.3 to 1.8) and 0.8 (95% CI, 0.3 to 2.0), respectively. These results were similar in analyses that also allowed for other conventional cardiovascular risk factors.

CONCLUSIONS

These results suggest that the Asn291Ser substitution in lipoprotein lipase is not associated with nonfatal ICVD in men but that it possibly confers a 2-fold risk in women.