Management of carotid atherosclerosis in stroke.

Internal carotid artery atherosclerosis is a major risk factor for stroke, accounting for 15-20% of ischaemic strokes. Revascularisation procedures-either carotid endarterectomy or carotid artery stenting-can reduce the risk of stroke for those with significant (>50%) luminal stenosis but particularly for those with more severe (70-99%) stenosis. However, advances in medical pharmacotherapy have implications for the relative benefit from surgery for symptomatic carotid atherosclerosis, as well as our approach to asymptomatic disease. This review considers the evidence underpinning the current medical and surgical management of symptomatic carotid atherosclerosis, the importance of factors beyond the degree of luminal stenosis, and developments in therapeutic strategies. We also discuss the importance of non-stenotic but high-risk carotid atherosclerotic plaques on the cause of stroke, and their implications for clinical practice.

Molecular magnetic resonance imaging of myeloperoxidase activity identifies culprit lesions and predicts future atherothrombosis.

Aims: Unstable atherosclerotic plaques have increased activity of myeloperoxidase (MPO). We examined whether molecular magnetic resonance imaging (MRI) of intraplaque MPO activity predicts future atherothrombosis in rabbits and correlates with ruptured human atheroma. Methods and results: Plaque MPO activity was assessed in vivo in rabbits (n = 12) using the MPO-gadolinium (Gd) probe at 8 and 12 weeks after induction of atherosclerosis and before pharmacological triggering of atherothrombosis. Excised plaques were used to confirm MPO activity by liquid chromatography-tandem mass spectrometry (LC-MSMS) and to determine MPO distribution by histology. MPO activity was higher in plaques that caused post-trigger atherothrombosis than plaques that did not. Among the in vivo MRI metrics, the plaques' R1 relaxation rate after administration of MPO-Gd was the best predictor of atherothrombosis. MPO activity measured in human carotid endarterectomy specimens (n = 30) by MPO-Gd-enhanced MRI was correlated with in vivo patient MRI and histological plaque phenotyping, as well as LC-MSMS. MPO-Gd retention measured as the change in R1 relaxation from baseline was significantly greater in histologic and MRI-graded American Heart Association (AHA) type VI than type III-V plaques. This association was confirmed by comparing AHA grade to MPO activity determined by LC-MSMS. Conclusion: We show that elevated intraplaque MPO activity detected by molecular MRI employing MPO-Gd predicts future atherothrombosis in a rabbit model and detects ruptured human atheroma, strengthening the translational potential of this approach to prospectively detect high-risk atherosclerosis.

Adherence to vascular care guidelines for emergency revascularization of chronic limb-threatening ischemia.

Objective: In 2022, the National Health Service Commissioning for Quality and Innovation (CQUIN) indicator for vascular surgery, with its pay-for-performance incentive for timely (5-day) revascularization of chronic limb-threatening ischemia (CLTI), was introduced. We sought to assess its effects in terms of (1) changes in the care pathway process measures relating to timing and patient outcomes; and (2) adherence to the Peripheral Arterial Disease Quality Improvement Framework (PAD-QIF) guidelines for patients admitted with CLTI. Methods: A retrospective before-and-after cohort study was performed from January to June 2022 of nonelective admissions for CLTI who underwent revascularization (open, endovascular, or hybrid) at Cambridge University Hospitals National Health Service Foundation Trust, a regional vascular "hub." The diagnostic and treatment pathway timing-related process measures recommended in the PAD-QIF were compared between two 3-month cohorts-before vs after introduction of the CQUIN. Results: For the two cohorts (before vs after CQUIN), 17 of 223 and 17 of 219 total admissions met the inclusion criteria, respectively. After introduction of financial incentives, the percentage of patients meeting the 5-day targets for revascularization increased from 41.2% to 58.8% (P = .049). Improvements were also realized in the attainment of PAD-QIF targets for a referral-to-admission time of ≤2 days (from 82.4% to 88.8%; P = .525) and admission-to-specialist-review time of ≤14 hours (from 58.8% to 76.5%; P = .139). An increase also occurred in the percentage of patients receiving imaging studies within 2 days of referral (from 58.8% to 70.6%; P = .324). The reasons for delay included operating list pressures and unsuitability for intervention (eg, active COVID-19 [coronavirus disease 2019] infection). No statistically significant changes to patient outcomes were observed between the two cohorts in terms of complications (pre-CQUIN, 23.5%; post-CQUIN, 41.2%; P = .086), length of stay (pre-QUIN, 12.0 ± 12.0 days; post-QUIN, 15.0 ± 21.0 days; P = .178), and in-hospital mortality (pre-QUIN, 0%; post-QUIN, 5.9%). Other PAD-QIF targets relating to delivery of care were poorly documented for both cohorts. These included documented staging of limb threat severity with the WIfI (wound, ischemia, foot infection) score (2.9% of patients; target >80%), documented shared decision-making (47.1%; target >80%), documented issuance of written information to patient (5.9%; target 100%), and geriatric assessment (6.3%; target >80%). Conclusions: The pay-for-performance incentive CQUIN indicators appear to have raised the profile for the need for early revascularization to treat CLTI, engaging senior hospital management, and reducing the time to revascularization in our cohort. Further data collection is required to detect any resultant changes in patient outcomes. Documentation of guideline targets for delivery of care was often poor and should be improved.

A State-of-the-Art Review of Intra-Operative Imaging Modalities Used to Quality Assure Endovascular Aneurysm Repair.

Endovascular aortic aneurysm repair (EVAR) is the preferred method for elective abdominal aortic aneurysm (AAA) repair. However, the success of this technique depends greatly on the technologies available. Intra-operative imaging is essential but can come with limitations. More complex interventions lead to longer operating times, fluoroscopy times, and greater contrast doses. A number of intra-operative imaging modalities to quality assure the success of EVAR have been developed. A systematic literature search was performed with separate searches conducted for each imaging modality in the study: computed tomography (CT), digital subtraction angiography (DSA), fusion, ultrasound, intra-operative positioning system (IOPS), and non-contrast imaging. CT was effective at detecting complications but commonly resulted in increased radiation and contrast dose. The effectiveness of DSA can be increased, and radiation exposure reduced, through the use of adjunctive technologies. We found that 2D-3D fusion was non-inferior to 3D-3D and led to reduced radiation and contrast dose. Non-contrast imaging occasionally led to higher doses of radiation. Ultrasound was particularly effective in the detection of type II endoleaks with reduced radiation and contrast use but was often operator dependent. Unfortunately, no papers made it past full text screening for IOPS. All of the imaging techniques discussed have advantages and disadvantages, and clinical context is relevant to guide imaging choice. Fusion and ultrasound in particular show promise for the future.

The risk of harm whilst waiting for varicose veins procedure.

INTRODUCTION: Varicose veins (VV) negatively impact quality of life (QoL) and have risks of major complications including bleeding, ulceration and phlebitis. During the COVID-19 pandemic, the VSGBI (Vascular Society of Great Britain and Ireland) and GIRFT (Get It Right First Time) classified VVs as lowest priority for intervention. OBJECTIVE: This study aims to determine harm caused and the impact on the QoL on patients waiting for their VVs procedures for more than 1 year. METHODS: This was a prospective study conducted at the Norfolk and Norwich University Hospital (NNUH). Patients with VVs awaiting intervention for >1 year were included in the study. Patients with CEAP C6 disease were considered to be too high risk to be invited for treatment during the Covid-19 pandemic. Patients were sent QoL questionnaires and underwent a telephone consultation to assess harm. Both generic (EQ-VAS and EQ-5D) and disease-specific (AVVQ and CIVIQ-14) instruments were utilised. There were no control groups available for comparison. RESULTS: 275 patients were identified (37.1% male) with median time on waiting list of 60 weeks (IQR 56-65). 19 patients (6.9%) came to major harm, including phlebitis (3.6%), bleeding (1.8%) and ulceration (1.8%). Fifty-two patients (18.9%) had minor harm, including worsening pain (12.7%) and swelling (6.2%). 6.9% reported psychological harm. Rising CEAP stage was also associated with worsening level of harm in patients with C5-6 disease (p < 0.0001). Only 8.7% stated they would decline surgery during the pandemic. 104 QoL questionnaires were returned. Median EQ-VAS and EQ-5D was 75 (IQR: 60-85) and 0.685 (0.566-0.761), respectively. Median AVVQ score was 23.2 (14.9-31.0) and CIVIQ-14 score was 33 (21-44).ConclusionsThis study highlights the impact of delaying VVs surgery during a pandemic. A significant rate of both major and minor as well as psychological harm was reported. In addition, VVs had a significant detriment to quality of life.

Comparing the Benefit of Duplex Ultrasound Surveillance Following Both Infrainguinal Bypass Surgery and Stenting for Femoro-Popliteal Disease.

OBJECTIVE: Duplex ultrasound surveillance (DUS) is commonly used following infrainguinal vein bypass. The role of DUS following endovascular revascularisation is as yet unclear. This study focuses on the role of DUS in a contemporary group of patients undergoing infrainguinal bypass or stent insertion. METHODS: All patients undergoing either an infrainguinal vein graft bypass or stent insertion into the femoro-popliteal segment (November 2014 - January 2017) were identified. Patients were followed up for 2 years. Data on entry into DUS, pre-operative characteristics, adjunctive pharmacotherapy and reintervention were collated. The primary outcomes were major lower limb amputation and mortality at 2 years post revascularisation. RESULTS: One hundred and thirty-five patients underwent infrainguinal vein bypass and 100 patients underwent stent insertion. 107 patients in the bypass cohort and 58 patients in the stent cohort entered DUS. For the bypass cohort, entering DUS was associated with a lower mortality rate (P = .003) but was not associated with an improvement in amputation rates. The odds ratio of major amputation or mortality was greater in the no surveillance group (4.58, 95% CI: 1.855 - 11.364). In the stent cohort, DUS was not associated with a significant improvement in either major amputation or death (odds ratio 2.13 (95% CI 0.903 - 5.051; P = .081). CONCLUSION: DUS was associated with improved survival rates in patients undergoing lower limb bypass but had no benefit in those patients undergoing stent insertion. The role of DUS following stent insertion in the femoropopliteal segment needs to be better defined.

Climate change and cardiovascular disease: implications for global health.

Climate change is the greatest existential challenge to planetary and human health and is dictated by a shift in the Earth's weather and air conditions owing to anthropogenic activity. Climate change has resulted not only in extreme temperatures, but also in an increase in the frequency of droughts, wildfires, dust storms, coastal flooding, storm surges and hurricanes, as well as multiple compound and cascading events. The interactions between climate change and health outcomes are diverse and complex and include several exposure pathways that might promote the development of non-communicable diseases such as cardiovascular disease. A collaborative approach is needed to solve this climate crisis, whereby medical professionals, scientific researchers, public health officials and policymakers should work together to mitigate and limit the consequences of global warming. In this Review, we aim to provide an overview of the consequences of climate change on cardiovascular health, which result from direct exposure pathways, such as shifts in ambient temperature, air pollution, forest fires, desert (dust and sand) storms and extreme weather events. We also describe the populations that are most susceptible to the health effects caused by climate change and propose potential mitigation strategies, with an emphasis on collaboration at the scientific, governmental and policy levels.

Intravascular Fluorescence Molecular Imaging of Atherosclerosis.

Optical molecular imaging using near-infrared fluorescence (NIRF) light is an emerging high-resolution imaging approach to image a wide range of molecular and cellular species in vivo. Imaging using NIR wavelengths (650-900 nm) enables deeper photon penetration into tissue and reduced tissue autofluorescence, resulting in higher sensitivity to detect exogenously administered NIR fluorophores (injectable molecular imaging agents). Greater imaging depth of several centimeters is further achievable in the NIR window as blood absorption is as an order of magnitude lower than in the visible range. Furthermore, as optical imaging is routinely performed in the cardiac catheterization laboratory (e.g., optical coherence tomography), intravascular NIRF offers a promising translational approach for clinical coronary and peripheral arterial imaging. To this point, the first human intravascular NIRF imaging study recently demonstrated the ability to detect NIR autofluorescence in patients with coronary atherosclerosis. This study provides a foundation for targeted intravascular NIRF molecular imaging studies in coronary patients. In this chapter, we detail system engineering, imaging agents and translational applications of intravascular NIRF molecular imaging.

Carotid Atheroinflammation Is Associated With Cerebral Small Vessel Disease Severity.

Background: Atherosclerosis is a systemic inflammatory disease, with common inflammatory processes implicated in both atheroma vulnerability and blood-brain barrier disruption. This prospective multimodal imaging study aimed to measure directly the association between systemic atheroma inflammation ("atheroinflammation") and downstream chronic cerebral small vessel disease severity. Methods: Twenty-six individuals with ischemic stroke with ipsilateral carotid artery stenosis of >50% underwent 18fluoride-fluorodeoxyglucose-positron emission tomography within 2 weeks of stroke. Small vessel disease severity and white matter hyperintensity volume were assessed using 3-tesla magnetic resonance imaging also within 2 weeks of stroke. Results: Fluorodeoxyglucose uptake was independently associated with more severe small vessel disease (odds ratio 6.18, 95% confidence interval 2.1-18.2, P < 0.01 for the non-culprit carotid artery) and larger white matter hyperintensity volumes (coefficient = 14.33 mL, P < 0.01 for the non-culprit carotid artery). Conclusion: These proof-of-concept results have important implications for our understanding of the neurovascular interface and potential therapeutic exploitation in the management of systemic atherosclerosis, particularly non-stenotic disease previously considered asymptomatic, in order to reduce the burden of chronic cerebrovascular disease.

Effects of Statin Therapy and Dose on Cardiovascular and Limb Outcomes in Peripheral Arterial Disease: A Systematic Review and Meta-analysis.

OBJECTIVE: Statin therapy is indicated in patients with peripheral arterial disease (PAD). National Institute for Health and Care Excellence guidelines suggest the use of "high intensity" statins, although evidence with PAD specific data are lacking. The effect of statin therapy and dose on outcomes in PAD is investigated. DATA SOURCES: Studies measuring statin use in PAD patients and outcomes were identified based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The EMBASE and MEDLINE databases were interrogated from January 1957 until February 2020. Twenty-two observational cohort studies and two randomised control trials were included (n = 268 611). REVIEW METHODS: Pooled estimates of dichotomous outcome data were calculated using the odds/hazard ratios (OR/HR) and 95% confidence interval (CI). Meta-analysis was conducted using the inverse variance or Mantel-Haenszel method. Outcomes included all cause mortality (ACM), cardiovascular mortality (CVM), major adverse cardiac events (MACE), and amputation. Subgroup analysis was performed on studies comparing patients taking high dose vs. combined low and moderate doses of statins. The GRADE criteria assessed the quality of evidence for outcomes. RESULTS: Statin therapy (vs. no statins) was significantly protective for ACM: OR 0.68 (95% CI 0.60 - 0.76) (number needed to treat [NNT] = 48), HR 0.74 (95% CI 0.70 - 0.78) (NNT = 10 - 91); MACE: OR 0.84 (95% CI 0.78 - 0.92) (NNT = 53), HR 0.78 (95% CI 0.65 - 0.93) (NNT = 167); and amputations: OR 0.59 (95% CI 0.33 - 1.07) (NNT = 333), HR 0.74 (95% CI 0.62 - 0.89) (NNT = 50). High doses of statins (vs. combined low and moderate doses) were significantly better protective against ACM OR 0.69 (95% CI 0.43 - 1.09) (NNT = 17), HR 0.74 (95% CI 0.62 - 0.89) (NNT = 16 - 200) but work less significantly for MACE OR 0.77 (95% CI 0.49 - 1.21) (NNT = 25). Amputations were less frequent in patients on high doses HR 0.78 (95% CI 0.69 - 0.90) (NNT = 53 - 1 000). CONCLUSION: Higher dosing of statins confers a significant improvement in patient outcomes, especially ACM and amputations, although the quality of the evidence was variable. Such findings require confirmation in larger, PAD specific trials.

Near-Infrared Autofluorescence in Atherosclerosis Associates With Ceroid and Is Generated by Oxidized Lipid-Induced Oxidative Stress.

[Figure: see text].

Clinical practice patterns and ascertainment bias for cardiovascular events in a randomized trial: A survey of investigators in the BEST-CLI trial.

Ascertainment bias is a well-recognized source of bias in research, but few studies have systematically analyzed sources of ascertainment bias in randomized trials in which blinding is not possible and endpoint assessment is not protocolized. In the current study, we sought to evaluate differences in the clinical practice patterns of trial investigators with respect to bias in the ascertainment of pre-revascularization patient risk and the incidence of secondary endpoints post-revascularization. We conducted a cross-sectional survey of active investigators (n = 936) from the Best Endovascular Versus Best Surgical Therapy for Patients with Critical Limb Ischemia (BEST-CLI) trial. The total survey response rate was 19.6% (183/936). Vascular surgeons were more likely than nonsurgical interventionalists to order tests for cardiac complications after both surgical bypass (p < 0.001) and endovascular revascularization (p = 0.038). Post-procedure, investigators were more likely to order additional testing for cardiac complications in open surgery versus endovascular cases (7% vs 16% never, 41% vs 65% rarely, 43% vs 17% sometimes, 9% vs 2% always, respectively; p < 0.0001). Significant variation in practice patterns exist in the pre- and post-procedure assessment of cardiac risk and events for patients with CLI undergoing revascularization. Variation in the ascertainment of risk and outcomes according to the type of revascularization procedure and physician specialty should be considered when interpreting the results of clinical studies, such as the BEST-CLI trial. ClinicalTrials.gov Identifier: NCT02060630.

Assessing robustness of carotid artery CT angiography radiomics in the identification of culprit lesions in cerebrovascular events.

Radiomics, quantitative feature extraction from radiological images, can improve disease diagnosis and prognostication. However, radiomic features are susceptible to image acquisition and segmentation variability. Ideally, only features robust to these variations would be incorporated into predictive models, for good generalisability. We extracted 93 radiomic features from carotid artery computed tomography angiograms of 41 patients with cerebrovascular events. We tested feature robustness to region-of-interest perturbations, image pre-processing settings and quantisation methods using both single- and multi-slice approaches. We assessed the ability of the most robust features to identify culprit and non-culprit arteries using several machine learning algorithms and report the average area under the curve (AUC) from five-fold cross validation. Multi-slice features were superior to single for producing robust radiomic features (67 vs. 61). The optimal image quantisation method used bin widths of 25 or 30. Incorporating our top 10 non-redundant robust radiomics features into ElasticNet achieved an AUC of 0.73 and accuracy of 69% (compared to carotid calcification alone [AUC: 0.44, accuracy: 46%]). Our results provide key information for introducing carotid CT radiomics into clinical practice. If validated prospectively, our robust carotid radiomic set could improve stroke prediction and target therapies to those at highest risk.

An Assessment of Available Information on the World Wide Web for Patients with Lower Limb Arterial Disease.

OBJECTIVE: The quality of patient information relating to intermittent claudication (IC) and peripheral arterial disease (PAD) on the World Wide Web was assessed. METHODS: The quality of websites and YouTube videos was assessed using the search terms "intermittent claudication" and "peripheral arterial disease". The first 50 hits screened for each search term from the three largest search engines by market share, and the first 20 videos from YouTube were screened. Website quality was scored using the University of Michigan Consumer Health Website tool (maximum score 80). Readability was calculated using the Flesch Reading Ease (FRE) score (maximum score 100). Videos were classified by content and upload source. Video reliability was assessed using the JAMA benchmark criteria. Video educational content was assessed using the Global Quality Score (GQS). Subjective content assessment was undertaken. RESULTS: Seventy-six websites were analysed. The majority of websites for both IC (51.7%) and PAD (72.3%) were rated as weak. The median Michigan score for IC (27; interquartile range [IQR] 15, 32.5) was lower that the score for PAD (31; IQR 25.5, 38.8; p = .030). The majority of websites for both IC (69%) and PAD (68.1%) were rated as requiring an above average reading level. The overall median FRE score was 55.9 (IQR 46.6, 60.6) for IC and 55.3 (IQR 44.6, 59.3) for PAD. Twenty-two videos were analysed. Of the 14 videos evaluated as part of the PAD search, the median JAMA score was 2 (2 - 3), the median GQS score was 3 (3 - 3) and the evaluation of content score was 8.5 (7.25 - 11.5). The equivalent scores for the IC search were 2 (2 - 2), 3 (3 - 4), and 5.5 (5 - 8). CONCLUSION: The educational quality and reliability of information both in written and video form on the internet is low. Attention needs to focus on improving the quality of all forms of information delivery to allow proper advocacy for patients.

Atherosclerosis imaging using PET: Insights and applications.

PET imaging is able to harness biological processes to characterise high-risk features of atherosclerotic plaque prone to rupture. Current radiotracers are able to track inflammation, microcalcification, hypoxia, and neoangiogenesis within vulnerable plaque. 18 F-fluorodeoxyglucose (18 F-FDG) is the most commonly used radiotracer in vascular studies and is employed as a surrogate marker of plaque inflammation. Increasingly, 18 F-FDG and other PET tracers are also being used to provide imaging endpoints in cardiovascular interventional trials. The evolution of novel PET radiotracers, imaging protocols, and hybrid scanners are likely to enable more efficient and accurate characterisation of high-risk plaque. This review explores the role of PET imaging in atherosclerosis with a focus on PET tracers utilised in clinical research and the applications of PET imaging to cardiovascular drug development.

Patient and Institutional Costs of Failure of Angioplasty of the Superficial Femoral Artery.

BACKGROUND: Debate surrounds the optimal management of superficial femoral artery (SFA) disease. Randomized trial data rarely reflect real world findings, specifically the consequences to the patient of angioplasty failure. We observed the effect of a failed SFA angioplasty on the need for repeated clinic visits, hospital readmissions, imaging requirements, and reinterventions. METHODS: We reviewed a consecutive series of 148 patients (94 men, median age 72 years) undergoing solely SFA angioplasty over a 2-year period. Patient preangioplasty demographics and 2-year post-PTA follow-up data were collated, including hospital attendances (inpatient/outpatient), further imaging (including radiation exposure) and revascularization attempts. We defined "failed angioplasty" as presence of clinical symptoms with radiological evidence of significant restenosis after an initial successful primary SFA angioplasty. RESULTS: Fifty-four patients represented with a failed angioplasty (median time of 4 months after index PTA). In this group, failure of index angioplasty resulted in a further 185 restenosis-related clinic visits and a total of 537 bed days of inpatient stay. This group underwent a further 149 imaging events and required a further 34 endovascular revascularization procedures and 12 infrainguinal bypass procedures. These interventions and investigations corresponded to overall effective radiation dose across all patients of 190.69 mSv. Of the cohort of 99 patients who did not have a "failed angioplasty," they required 100 clinic visits, 21 further scans (total radiation dose 6.42 mSv), and 36 bed days of inpatient admission. CONCLUSIONS: Failed angioplasty results in significant additional consequences for patients and health-care systems. Further work should focus on refining decision-making, providing the right procedure to the right patient at the right time.

Paclitaxel Drug-Coated Balloon Angioplasty Suppresses Progression and Inflammation of Experimental Atherosclerosis in Rabbits.

Paclitaxel drug-coated balloons (DCBs) reduce restenosis, but their overall safety has recently raised concerns. This study hypothesized that DCBs could lessen inflammation and reduce plaque progression. Using 25 rabbits with cholesterol feeding- and balloon injury-induced lesions, DCB-percutaneous transluminal angioplasty (PTA), plain PTA, or sham-PTA (balloon insertion without inflation) was investigated using serial intravascular near-infrared fluorescence-optical coherence tomography and serial intravascular ultrasound. In these experiments, DCB-PTA reduced inflammation and plaque burden in nonobstructive lesions compared with PTA or sham-PTA. These findings indicated the potential for DCBs to serve safely as regional anti-atherosclerosis therapy.

The Effect of Frailty on Long Term Outcomes in Vascular Surgical Patients.

OBJECTIVE: Frailty is a multidimensional vulnerability due to age associated decline. The impact of frailty on long term outcomes was assessed in a cohort of vascular surgical patients. METHODS: Patients aged over 65 years with a length of stay greater than two days admitted to a tertiary vascular unit over a single calendar year were included. Demographics, mode of admission, and diagnosis were recorded alongside a variety of frailty specific characteristics. Using the previously developed Addenbrookes Vascular Frailty Score (AVFS - 6 point score: anaemia on admission, lack of independent mobility, polypharmacy, Waterlow score > 13, depression, and emergency admission) the effect of frailty on five year mortality and re-admission rates was assessed using multivariable regression techniques. The AVFS was further refined to assess longer term outcomes. RESULTS: In total, 410 patients (median age 77 years) were included and followed up until death or five years from the index admission. One hundred and thirty-four were treated for aortic aneurysm, 75 and 96 for acute and chronic limb ischaemia respectively, 52 for carotid disease, and 53 for other pathologies. The in hospital mortality rate was 3.6%. The one, three, and five year survival rates were 83%, 70% and 59%; and the one, three, and five year re-admission free survival rates were 47%, 29%, and 22% respectively. Independent predictors of five year mortality were age, lack of independent mobility, high Charlson score, polypharmacy, evidence of malnutrition, and emergency admission (p < .010 for all). Patients with AVFS 0 or 1 had restricted mean survival times which were one year longer than those with AVFS 2 or 3 (p < .001), who in turn had restricted mean survival times over one year longer than those with AVFS of 4 or more (p < .001). CONCLUSION: Frailty factors are strong predictors of long term outcomes in vascular surgery. Further prospective studies are warranted to investigate its utility in clinical decision making.

Dual-Tracer Positron-Emission Tomography for Identification of Culprit Carotid Plaques and Pathophysiology In Vivo.

BACKGROUND: Inflammation and microcalcification are interrelated processes contributing to atherosclerotic plaque vulnerability. Positron-emission tomography can quantify these processes in vivo. This study investigates (1) 18F-fluorodeoxyglucose (FDG) and 18F-sodium fluoride (NaF) uptake in culprit versus nonculprit carotid atheroma, (2) spatial distributions of uptake, and (3) how macrocalcification affects this relationship. METHODS: Individuals with acute ischemic stroke with ipsilateral carotid stenosis of ≥50% underwent FDG-positron-emission tomography and NaF-positron-emission tomography. Tracer uptake was quantified using maximum tissue-to-background ratios (TBRmax) and macrocalcification quantified using Agatston scoring. RESULTS: In 26 individuals, median most diseased segment TBRmax (interquartile range) was higher in culprit than in nonculprit atheroma for both FDG (2.08 [0.52] versus 1.89 [0.40]; P<0.001) and NaF (2.68 [0.63] versus 2.39 [1.02]; P<0.001). However, whole vessel TBRmax was higher in culprit arteries for FDG (1.92 [0.41] versus 1.71 [0.31]; P<0.001) but not NaF (1.85 [0.28] versus 1.79 [0.60]; P=0.10). NaF uptake was concentrated at carotid bifurcations, while FDG was distributed evenly throughout arteries. Correlations between FDG and NaF TBRmax differed between bifurcations with low macrocalcification (rs=0.38; P<0.001) versus high macrocalcification (rs=0.59; P<0.001). CONCLUSIONS: This is the first study to demonstrate increased uptake of both FDG and NaF in culprit carotid plaques, with discrete distributions of pathophysiology influencing vulnerability in vivo. These findings have implications for our understanding of the natural history of the disease and for the clinical assessment and management of carotid atherosclerosis.