Management of peripheral arterial disease in primary care

Development and evaluation of a prediction model for peripheral artery disease-related major adverse limb events using novel biomarker data

OBJECTIVE

Prognostic tools for individuals with peripheral artery disease (PAD) remain limited. We developed prediction models for 3-year PAD-related major adverse limb events (MALE) using demographic, clinical, and biomarker data previously validated by our group.

METHODS

We performed a prognostic study using a prospectively recruited cohort of patients with PAD (n = 569). Demographic/clinical data were recorded including sex, age, comorbidities, previous procedures, and medications. Plasma concentrations of three biomarkers (N-terminal pro-B-type natriuretic peptide [NT-proBNP], fatty acid binding protein 3 [FABP3], and FABP4) were measured at baseline. The cohort was followed for 3 years. MALE was the primary outcome (composite of open/endovascular vascular intervention or major amputation). We trained three machine learning models with 10-fold cross-validation using demographic, clinical, and biomarker data (random forest, decision trees, and Extreme Gradient Boosting [XGBoost]) to predict 3-year MALE in patients. Area under the receiver operating characteristic curve (AUROC) was the primary model evaluation metric.

RESULTS

Three-year MALE was observed in 162 patients (29%). XGBoost was the top-performing predictive model for 3-year MALE, achieving the following performance metrics: AUROC = 0.88 (95% confidence interval [CI], 0.84-0.94); sensitivity, 88%; specificity, 84%; positive predictive value, 83%; and negative predictive value, 91% on test set data. On an independent validation cohort of patients with PAD, XGBoost attained an AUROC of 0.87 (95% CI, 0.82-0.90). The 10 most important predictors of 3-year MALE consisted of: (1) FABP3; (2) FABP4; (3) age; (4) NT-proBNP; (5) active smoking; (6) diabetes; (7) hypertension; (8) dyslipidemia; (9) coronary artery disease; and (10) sex.

CONCLUSIONS

We built robust machine learning algorithms that accurately predict 3-year MALE in patients with PAD using demographic, clinical, and novel biomarker data. Our algorithms can support risk stratification of patients with PAD for additional vascular evaluation and early aggressive medical management, thereby improving outcomes. Further validation of our models for clinical implementation is warranted.

The Identification and Evaluation of Interleukin-7 as a Myokine Biomarker for Peripheral Artery Disease Prognosis

Background/Objectives: Myokines have been demonstrated to be associated with cardiovascular diseases; however, they have not been studied as biomarkers for peripheral artery disease (PAD). We identified interleukin-7 (IL-7) as a prognostic biomarker for PAD from a panel of myokines and developed predictive models for 2-year major adverse limb events (MALEs) using clinical features and plasma IL-7 levels. Methods: A prognostic study was conducted with a cohort of 476 patients (312 with PAD and 164 without PAD) that were recruited prospectively. Their plasma concentrations of five circulating myokines were measured at recruitment, and the patients were followed for two years. The outcome of interest was two-year MALEs (composite of major amputation, vascular intervention, or acute limb ischemia). Cox proportional hazards analysis was performed to identify IL-7 as the only myokine that was associated with 2-year MALEs. The data were randomly divided into training (70%) and test sets (30%). A random forest model was trained using clinical characteristics (demographics, comorbidities, and medications) and plasma IL-7 levels with 10-fold cross-validation. The primary model evaluation metric was the F1 score. The prognostic model was used to classify patients into low vs. high risk of developing adverse limb events based on the Youden Index. Freedom from MALEs over 2 years was compared between the risk-stratified groups using Cox proportional hazards analysis. Results: Two-year MALEs occurred in 28 (9%) of patients with PAD. IL-7 was the only myokine that was statistically significantly correlated with two-year MALE (HR 1.56 [95% CI 1.12-1.88], p = 0.007). For the prognosis of 2-year MALEs, our model achieved an F1 score of 0.829 using plasma IL-7 levels in combination with clinical features. Patients classified as high-risk by the predictive model were significantly more likely to develop MALEs over a 2-year period (HR 1.66 [95% CI 1.22-1.98], p = 0.006). Conclusions: From a panel of myokines, IL-7 was identified as a prognostic biomarker for PAD. Using a combination of clinical characteristics and plasma IL-7 levels, we propose an accurate predictive model for 2-year MALEs in patients with PAD. Our model may support PAD risk stratification, guiding clinical decisions on additional vascular evaluation, specialist referrals, and medical/surgical management, thereby improving outcomes.

A machine learning algorithm for peripheral artery disease prognosis using biomarker data

Peripheral artery disease (PAD) biomarkers have been studied in isolation; however, an algorithm that considers a protein panel to inform PAD prognosis may improve predictive accuracy. Biomarker-based prediction models were developed and evaluated using a model development (n = 270) and prospective validation cohort (n = 277). Plasma concentrations of 37 proteins were measured at baseline and the patients were followed for 2 years. The primary outcome was 2-year major adverse limb event (MALE; composite of vascular intervention or major amputation). Of the 37 proteins tested, 6 were differentially expressed in patients with vs. without PAD (ADAMTS13, ICAM-1, ANGPTL3, Alpha 1-microglobulin, GDF15, and endostatin). Using 10-fold cross-validation, we developed a random forest machine learning model that accurately predicts 2-year MALE in a prospective validation cohort of PAD patients using a 6-protein panel (AUROC 0.84). This algorithm can support PAD risk stratification, informing clinical decisions on further vascular evaluation and management.

Best medical treatment in patients with PAD

Background: Guidelines recommend comprehensive lifestyle change in patients with peripheral arterial disease (PAD) to prevent cardiovascular events and death. When compared with other populations, patients with PAD are less likely to receive best medical therapies (BMT). The aim of this pilot study was to integrate all aspects of BMT in an intervention program and to determine the feasibility of such an approach by highlighting strengths and obstacles of a multi-aspect intervention. Patients and methods: Patients consecutively hospitalized due to symptomatic PAD between 01 December 2021 and 28 February 2022 were included and followed for ten weeks. We randomized into a lifestyle intervention (education on BMT, a list of regional contact data for supervised exercise, weekly counselling by phone for ten times) vs. standard of care (one contact to talk about BMT). Vascular Quality of Life Questionnaire - 6 (VascuQoL-6) was used to collect patient reported outcomes. Results: Of 50 eligible patients 40 agreed to participate (32.5% female, 72.5 years in mean). During follow-up nine patients dropped out (4 in intervention group vs. 5). As for risk factor modification one patient was able to reach a normal weight body-mass-index (BMI) and nine reduced weight. Two patients stopped smoking, three reduced their consumption. The reported adherence to medication was a hundred percent. No patient attended supervised exercise therapy but eight trained at a home-based setting according to guidelines. The mean score of VascuQoL-6 at follow-up was higher in the intervention group compared to the control group (17.4 vs. 13.8 points) at last contact with both groups increasing from baseline. Conclusions: This pilot study followed 40 patients for up to 10 weeks after inpatient treatment while we randomized a multi-aspect lifestyle intervention versus standard of care. Thereby, the current study illustrated the numerous obstacles and provided pragmatic solutions for the planning of studies on BMT in this target population.

A Randomized Trial Comparing Polymer Versus Suture-Based Vascular Closure Devices for Arterial Closure Following Lower-Limb Arterial Endovascular Revascularization

PURPOSES

The primary objective of this study (STEP trial) was to compare the efficacy of the polymer-based FemoSeal® vascular closure device (VCD) and the suture-based ProGlide® VCD in achieving hemostasis at the femoral access site after lower-limb arterial endovascular revascularization.

MATERIALS AND METHODS

STEP was a multicenter randomized clinical trial including patients undergoing lower-limb arterial endovascular revascularization. The primary endpoint was technical success 5 h after the VCD intervention, defined as achievement of hemostasis without the need for a follow-up intervention at the access site and without a 2-g/dL drop in hemoglobin.

RESULTS

Between December 2017 and April 2019, 113 patients were assigned to the FemoSeal® group (FS) and 117 to the ProGlide® group (PG). VCD interventions were technically successful for 90 FS patients (80%) and 58 PG patients (50%) (odds ratio, 3.98; 95% CI, 2.22 to 7.14; p < 0.0001). This difference in success rates between FS and PG is partly explained by more frequent recourse to manual compression (FS: n = 19; PG: n = 45) and an additional VCD (FS: n = 0; PG: n = 23) in the latter group. After 5 h, 87% of FS patients and 69% of PG patients resumed ambulation (odds ratio: 3.07; 95% CI: 1.93 to 6.15; p = 0.0016).

CONCLUSIONS

In patients undergoing lower-limb arterial endovascular revascularization, FemoSeal® was superior to ProGlide® in terms of technical success.

CLINICAL TRIAL REGISTRATION

Step trial was registered on http://ClinicalTrials.gov (NCT03192033).

[Amputation as an anticipated consequence of peripheral artery disease and ways to improve the prognosis of limb salvage]

Peripheral artery disease is a common and acute social burden worldwide. The main method of treatment of PAD consists in open surgical or endovascular revascularization. However, despite steady growth of the number and quality of interventions, the incidence of lower-limb amputation still remains at a high level. Lower-limb amputation is a severe psychological blow for the patient and leads to significant deterioration of his or her quality of life, as well as has an extremely negative prognosis concerning the frequency of subsequent complications and survival. Consequences of amputations include not only severe disability but also an unfavourable prognosis of life, thus determining the necessity of adequate prevention of such events. Reconstructive and endovascular operations, as well as amputations are associated with a significant increase of the probability of the development of major adverse cardiovascular events, the frequency of repeat hospitalizations and, finally, the cost of treatment. Prescribing pathogenetically substantiated antithrombotic therapy is considered to be one of the methods to improve the results of surgical treatment and prognosis for the patient. Presented in the article is a literature review making it possible to assess the risks and consequences of amputations in patients with PAD, as well as to determine therapy capable of improving the prognosis.

Effect of treatment of peripheral arterial disease on the onset of anaerobic exercise during cardiopulmonary exercise testing

OBJECTIVE

Cardiopulmonary exercise testing (CPET) is often used to assess pre-operative fitness in elderly patients, in whom peripheral arterial disease (PAD) is highly prevalent, but may affect the results of CPET by early lactate release due to muscle ischemia. This study investigated the effect revascularization of PAD on oxygen delivery (VO2 ) during CPET.

METHOD

We conducted a prospective cohort study of 30 patients, who underwent CPET before and after treatment of ilio-femoral PAD. The primary outcome measure was difference in VO2 at the lactate threshold (LT) before and after revascularization. Secondary outcome measures were the relationship between change in VO2 at LT and peak exercise and change in ankle-brachial index (ABI) differential.

RESULTS

The study was approved by the North West-Lancaster Research and Ethics committee (reference 15/NW/0801) and registered in clinicaltrial.gov (reference NCT02657278). As specified in the study protocol, 30 patients were recruited but only 20 (15 men), with a mean age of 62 years, completed pre- and post-treatment CPETs. Twelve patients demonstrated an improvement in VO2 at LT after revascularization, but the difference did not achieve statistical significance (mean difference (95% CI) = 1.43 (-0.21 to 3.08) ml/kg/min; (p = 0.085). There was, however, a significant improvement in VO2 , VE/CO2 , workload and Borg breathlessness and leg fatigue score at peak exercise after revascularization. There was no significant correlation between change in VO2 at LT (r = -0.11, p = 0.65) or change in VO2 at peak and ABI differential (r = -0.14, p = 0.55).

CONCLUSION

Revascularization of PAD led to significant improvement in multiple peak/maximal exercise parameters within a few weeks and without exercise training. We were unable to demonstrate a statistically significant improvement in VO2 at LT albeit in a majority of subjects this exceeded what we pre-defined as clinically significant.

Improving health behaviors in patients with peripheral arterial disease - A pilot study of supported self-management

PURPOSE OF THE RESEARCH

This pilot study reports the feasibility of a future randomized controlled trial (RCT) investigating the effect of supported self-management through low-intensity psychological intervention in patients with peripheral arterial disease (PAD) resulting in claudication. The study protocol, measurement instrument, data collection, and analysis were evaluated. Clinical outcome measures include depression and anxiety scores, smoking cessation, activity (step count), weight, and quality of life. Both Quantitative and Qualitative data were collected to evaluate participant experience and the clinical impact of a supported self-management intervention delivered in a routine clinical setting.

METHODS

Participants received an initial one to one assessment with a health psychologist. Demographic data and baseline clinical outcome measures were recorded. These included Hospital Anxiety and Depression Scale score (HADS), health-related quality of life questionnaire (EQ-5D-3 L), number of cigarettes smoked daily, weight/BMI, and daily step count. Participants each received an activity tracker to record daily step count and were followed up weekly to provide psychological input, including goal setting, overcoming barriers, and preventing relapse. Quantitative data collection was scheduled at baseline, 3 and 6 months (final follow-up). At the final follow-up, participants provided qualitative feedback reflecting upon their experience of the intervention and its impact. Descriptive statistical analysis and simple paired samples t-test were employed in data evaluation.

RESULTS

The sample size was small (n = 30). Twenty-three participants were followed up to 6 months. Depression scores improved with statistical significance from baseline to 6-month follow-up. Eight participants stopped smoking (47% reduction); a further 9 greatly reduced their intake. A borderline statistically significant increase of daily step count was achieved between baseline and 6-month follow-up. In addition, positive weight loss trends were observed in a predominantly obese or overweight cohort. The qualitative feedback highlighted participants understood and embraced the information delivered regarding the importance of health behavior change. Participants were able to link tailored action plans with what mattered to them with the help of the Health Psychologist.

CONCLUSION

This study embraces the contemporary ideology of enabling self-management of long-term conditions to improve clinical outcomes. As a pilot study, we have shown that an expanded, randomized controlled trial is both safe and feasible. A positive trend in clinical outcomes suggests this patient group may benefit from supported self-management through low-intensity psychological intervention, where other forms of early intervention have historically faltered.

Comparative 12-Month Outcomes of Drug-Coated Balloon Versus Non-Drug-Coated Balloon Revascularization Strategy in Chronic Limb-Threatening Ischemia: Results From the XLPAD Registry

BACKGROUND

Endovascular therapy is often the preferred first treatment option for chronic limb threatening ischemia (CLTI) patients. Drug coated balloons (DCB) reduce restenosis rates compared to percutaneous transluminal angioplasty (PTA), however DCB use has not been studied systematically in patients with CLTI. Thus, the optimal treatment option for these complex lesions remains controversial.

METHODS

We report on 327 patients with CLTI treated either with DCB (n = 105) or non-DCB (n = 222) for femoropopliteal disease. Data were retrieved from the Excellence in Peripheral Artery Disease (XLPAD) registry (NCT01904851). Two DCB types were used at the discretion of the operator: Lutonix® (BARD Peripheral Vascular, Inc., Tempe, AZ, USA) and IN.PACT AdmiralTM (Medtronic, Santa Rosa, CA, USA). Odds ratios and the respective 95% confidence interval were synthesized to examine the association between the two groups in terms of all-cause mortality, target limb repeat endovascular or surgical revascularization, target vessel revascularization (TVR), major and minor amputation at 12 months of follow up.

RESULTS

The mean lesion length was 150.0 mm (SD:123.2) and 151.2 mm (SD:108.3) for the DCB and non-DCB group respectively. No difference between the two groups was detected in terms of all-cause mortality (2.86%vs2.7%,p = .94), target limb repeat endovascular or surgical revascularization (16.19%vs12.61%,p = .25), TVR (16.19%vs.11.71%,p = .26) or minor amputation (15.24%vs10.81%,p = .25) at 12 months of follow up. Although a higher incidence of 12 months major amputation was observed in the DCB group (11%vs.4%,p = .01), after adjusting for several risk factors the odds of major amputation were not statistically different between the DCB and non-DCB groups (OR:1.54;95%CI:0.53-4.51;p = .43).

CONCLUSIONS

Both DCB and non-DCB strategies are effective modalities for revascularization of patients with CLTI. No differences were identified between the DCB and non-DCB group in terms of late outcomes during 12 months of follow up.

Feasibility of ischemic leg ulcer healing using percutaneous techniques: a real-life study

Background

Percutaneous transluminal angioplasty is established as the first-line vascular procedure in patients with lower extremity artery disease.

Purpose

We aimed to evaluate the technical and clinical effectiveness of percutaneous transluminal angioplasty in the management of ischemic foot ulcers.

Material and Methods

All consecutive patients presenting with a foot ulcer at the outpatient vascular surgery clinic of our hospital between June 2009 and June 2015 were evaluated using foot pulse assessment, ankle-brachial index, and duplex scanning. If non-invasive parameters suggested lower extremity artery disease, CT angiography and/or digital subtraction angiography were performed and a percutaneous transluminal angioplasty was carried out when feasible during the same session. All patients were followed until healing, amputation, death, or for at least two years. Short- and long-term clinical success was evaluated based on ulcer size and appearance. Patients with worsening ulcers after percutaneous transluminal angioplasty underwent bypass grafting or amputation.

Results

Percutaneous transluminal angioplasty was performed in 161 patients (100%) with stenoses > 50%, including cases lesions > 10 cm and/or multiple/calcified lesions, 144 of which completed the study. In 88 (61.2%) patients, percutaneous transluminal angioplasty was performed in the suprapopliteal axis exclusively, in 10 (6.8%) patients in the infrapopliteal axis only, and in 46 (31.9%) in both levels. Percutaneous transluminal angioplasty was technically successful in 141 (98%) patients. After 3.1 years, the rate of healing was 68%, limb salvage 88%, overall survival 69.5%, and amputation-free survival 64%.

Conclusion

Our data suggest that percutaneous transluminal angioplasty for ischemic foot ulceration treatment is in the majority of patients feasible, effective, and safe with high rates of healing and limb salvage.

Nurses' and patients' experiences and preferences of the ankle-brachial pressure index and multi-site photoplethysmography for the diagnosis of peripheral arterial disease: A qualitative study

Peripheral arterial disease is a global health problem, affecting around 20% of people aged over 60 years. Whilst ankle-brachial pressure index (ABPI) is regularly used for diagnosis, it has a number of limitations, which have presented a need for alternative methods of diagnosis. Multi-site photoplethysmography (MPPG) is one such method, but evidence of acceptability of both methods is lacking. This study aims to describe and compare preferences and experiences amongst nurses and patients of ABPI and MPPG use in primary care. We used qualitative research methods in the context of a clinical diagnostic study comparing ABPI with MPPG. Use of ABPI and MPPG by 13 nurses were observed with 51 patients across general practice surgeries in North-East England in 2015/16. Follow-up semi-structured interviews were conducted with 12 nurses and 27 patients. Data were thematically analysed. Two major themes were identified: (1) device preferences; (2) test discomfort and anxiety. There was a compelling preference for MPPG due to ease of use, speed of the test, patient comfort, and perceived device accuracy/objectivity. However some patients struggled to identify a preference, describing ambivalence to medical testing. ABPI was deemed uncomfortable and painful, particularly when the blood pressure cuff was inflated at the lower limbs. There was also evidence of anxiety amongst patients when their foot pulses were not identified using ABPI. Whilst ABPI is a non-invasive and routine procedure it was associated with a number of drawbacks in clinical practice. Nurses required considerable dexterity to employ the test, and it resulted in anxiety amongst some patients. Conversely, MPPG was deemed to be easier and quicker to use, and perceived to be less subjective. Should diagnostic accuracy and cost be comparable to ABPI, then the findings of this study suggest MPPG would be preferable to ABPI for patients as well as nurses.

Negotiating commissioning pathways for the successful implementation of innovative health technology in primary care

Background

Commissioning innovative health technologies is typically complex and multi-faceted. Drawing on the negotiated order perspective, we explore the process by which commissioning organisations make their decisions to commission innovative health technologies. The empirical backdrop to this discussion is provided by a case study exploring the commissioning considerations for a new photoplethysmography-based diagnostic technology for peripheral arterial disease in primary care in the UK.

Methods

The research involved an empirical case study of four Clinical Commissioning Groups (CCGs) involved in the commissioning of services in primary and secondary care. Semi-structured in-depth interviews (16 in total) and two focus groups (a total of eight people participated, four in each group) were conducted with key individuals involved in commissioning services in the NHS including (i) senior NHS clinical leaders and directors (ii) commissioners and health care managers across CCGs and (iii) local general practitioners.

Results

Commissioning of a new diagnostic technology for peripheral arterial disease in primary care involves high levels of protracted negotiations over funding between providers and commissioners, alliance building, conflict resolution and compromise of objectives where the outcomes of change are highly contingent upon interventions made across different care settings. Our evidence illustrates how reconfigurations of inter-organisational relations, and of clinical and related work practices required for the successful implementation of a new technology could become the major challenge in commissioning negotiations.

Conclusions

Innovative health technologies such as the diagnostic technology for peripheral arterial disease are commissioned in care pathways where the value of such technology is realised by those delivering care to patients. The detail of how care pathways are commissioned is complex and involves high degrees of uncertainty concerning such issues as prioritisation decisions, patient benefits, clinical buy-in, value for money and unintended consequences. Recent developments in the new care models and integrated care systems (ICSs) in the UK offer a unique opportunity for the successful commissioning arrangements of innovative health technologies in primary care such as the new diagnostic technology for peripheral arterial disease.

Classification of Carotid Artery Intima Media Thickness Ultrasound Images with Deep Learning

Cerebrovascular accident due to carotid artery disease is the most common cause of death in developed countries following heart disease and cancer. For a reliable early detection of atherosclerosis, Intima Media Thickness (IMT) measurement and classification are important. A new method for decision support purpose for the classification of IMT was proposed in this study. Ultrasound images are used for IMT measurements. Images are classified and evaluated by experts. This is a manual procedure, so it causes subjectivity and variability in the IMT classification. Instead, this article proposes a methodology based on artificial intelligence methods for IMT classification. For this purpose, a deep learning strategy with multiple hidden layers has been developed. In order to create the proposed model, convolutional neural network algorithm, which is frequently used in image classification problems, is used. 501 ultrasound images from 153 patients were used to test the model. The images are classified by two specialists, then the model is trained and tested on the images, and the results are explained. The deep learning model in the study achieved an accuracy of 89.1% in the IMT classification with 89% sensitivity and 88% specificity. Thus, the assessments in this paper have shown that this methodology performs reasonable results for IMT classification.

Cost Analysis of Imaging Diagnostic Tests Used in the Management of Peripheral Arterial Disease

The purpose of this paper was to compare the costs of three noninvasive diagnostic investigations as the initial tests in peripheral artery disease management in Romania.

A cost analysis of three imaging diagnostic tests was performed at the university hospital in Timișoara, Romania. The tests were as follows: arterial Duplex Ultrasound Scanning, Computed Tomography Angiography, and Contrast-enhanced Magnetic Resonance Angiography. The evaluation of the diagnostic test performance was performed together with the calculation of the real costs of each investigation. Finally, an economic evaluation of different diagnostic tests was done.

A number of 46 patients (36 male and 10 female) were included in the study. The selected patients have been subjected to a total number of 61 diagnostic tests prior to the therapeutic decision. Both in terms of sensitivity and specificity, Duplex Ultrasound Scanning and Computed Tomography Angiography showed little difference in our study. The cost analysis results showed a net economic advantage if Duplex Ultrasound Scanning is applied as a diagnostic method under conditions of obtaining a similar effect.

In conclusion, Duplex Ultrasound Scanning is accurate, safe, and cost-effective in designing the final therapeutic plan in peripheral artery disease (PAD), especially in the femoropopliteal segment.

Systematic Review of Economic Models Used to Compare Techniques for Detecting Peripheral Arterial Disease

BACKGROUND AND OBJECTIVE

Peripheral arterial disease (PAD) is a common condition, in which atherosclerotic narrowing in the arteries restricts blood supply to the leg muscles. In order to support future model-based economic evaluations comparing methods of diagnosis in this area, a systematic review of economic modelling studies was conducted.

METHODS

A systematic literature review was performed in June 2017 to identify model-based economic evaluations of diagnostic tests to detect PAD, with six individual databases searched. The review was conducted in accordance with the methods outlined in the Centre for Reviews and Dissemination's guidance for undertaking reviews in healthcare, and appropriate inclusion criteria were applied. Relevant data were extracted, and studies were quality assessed.

RESULTS

Seven studies were included in the final review, all of which were published between 1995 and 2014. There was wide variation in the types of diagnostic test compared. The majority of the studies (six of seven) referenced the sources used to develop their model, and all studies stated and justified the structural assumptions. Reporting of the data within the included studies could have been improved. Only one identified study focused on the cost-effectiveness of a test typically used in primary care.

CONCLUSIONS

This review brings together all applied modelling methods for tests used in the diagnosis of PAD, which could be used to support future model-based economic evaluations in this field. The limited modelling work available on tests typically used for the detection of PAD in primary care, in particular, highlights the importance of future work in this area.

Implementation of a supervised exercise therapy programme

INTRODUCTION

Guidelines for peripheral vascular disease state that supervised exercise therapy (SET) programmes improve walking distance and quality of life in patients with intermittent claudication. This paper outlines the steps needed to implement a successful SET programme and discusses some of the challenges.

METHODS

Edinburgh Leisure was approached to coordinate an exercise programme aimed at rehabilitation, run by level 4 members of the Register of Exercise Professionals. It is estimated to be cost effective at 500 referrals compared with physiotherapy referral. Success is measured by walking distance, reduction of symptoms and weight loss. Edinburgh Leisure also measures success with feedback and membership numbers at its health centres.

RESULTS

Between 4 March 2014 and 25 January 2016, 155 patients were referred to the SET programme with a median age of 68 years (range: 39-95 years) and a male-to-female ratio of 1.2:1. Of these, 117 patients attended and 29 have completed the programme. The mean walking distance increased from 298.5m (range: 150-385m) to 360m (range: 195-482m), an improvement of 20%. Increasing class numbers and venues, and introducing evening classes to make the programme accessible to more patients has addressed initial patient engagement issues.

CONCLUSIONS

Collaboration with motivated local authorities can help implement a successful healthcare intervention. Early analysis is necessary to improve the system and engage as many patients as possible. The SET programme discussed has shown similar results to those of previous studies but is available at no personal cost to regional patients with intermittent claudication.

Innovative Multi-Site Photoplethysmography Analysis for Quantifying Pulse Amplitude and Timing Variability Characteristics in Peripheral Arterial Disease

Photoplethysmography (PPG) is a simple-to-perform vascular optics measurement technique that can detect blood volume changes in the microvascular bed of tissue. Beat-to-beat analysis of the PPG waveform enables the study of the variability of pulse features, such as the amplitude and the pulse arrival time (PAT), and when quantified in the time and frequency domains, has considerable potential to shed light on perfusion changes associated with peripheral arterial disease (PAD). In this pilot study, innovative multi-site bilateral finger and toe PPG recordings from 43 healthy control subjects and 31 PAD subjects were compared (recordings each at least five minutes, collected in a warm temperature-controlled room). Beat-to-beat normalized amplitude variability and PAT variability were then quantified in the time-domain using two simple statistical measures and in the frequency-domain bilaterally using magnitude squared coherence (MSC). Significantly reduced normalized amplitude variability (healthy control 0.0384 (interquartile range 0.0217–0.0744) vs. PAD 0.0160 (0.0080–0.0338) (p < 0.0001)) and significantly increased PAT variability (healthy control 0.0063 (0.0052–0.0086) vs. PAD 0.0093 (0.0078–0.0144) (p < 0.0001)) was demonstrated for the toe site in PAD using the time-domain analysis. Frequency-domain analysis demonstrated significantly lower MSC values across a range of frequency bands for PAD patients. These changes suggest a loss of right-to-left body side coherence and cardiovascular control in PAD. This study has also demonstrated the feasibility of using these measurement and analysis methods in studies investigating multi-site PPG variability for a wide range of cardiac and vascular patient groups.

Cardiovascular risk reduction in referrals to outpatient vascular clinics

Introduction

Patients with peripheral arterial disease (PAD), aneurysmal disease (AD) or carotid atherosclerosis are at high cardiovascular risk, necessitating secondary cardiovascular protection. The aim of this study was to determine compliance with cardiovascular risk reduction guidelines in new patients referred to vascular clinics.

Methods

A multicentre collaborative national observational audit of new patients referred to eight tertiary general vascular clinics over a three-month period in England and Wales was conducted by the Vascular and Endovascular Research Network (VERN). Referral letters, case notes and investigations were reviewed by local investigators, and data analysed by VERN.

Results

A total of 656 patients were included in the study: 73.2% had PAD, 23.2% had AD and 3.7% had carotid atherosclerosis. A third (37.5%) were current smokers, two-thirds (61.7%) were on antiplatelet therapy and two-thirds (61.5%) were on statin therapy. Smoking was more prevalent in the PAD cohort (PAD 41.4%, AD 27.5%, p =0.003). However, more PAD patients were on antiplatelet therapy (PAD 63.9%, AD 53.3%, p =0.024). Both antiplatelet and statin prescription significantly increased with the number of cardiovascular risk factors. Patients with a previous cardiac or cerebrovascular history were more likely to have stopped smoking, and to be on antiplatelet and statin therapy (p <0.0001 for each). Overall, 47.3% of patients were on both antiplatelet and statin therapy, and 28.9% were on antiplatelet and statin therapy and not smoking.

Conclusions

This study highlights deficiencies in cardiovascular risk minimisation in patients with established vascular disease. Patients with concomitant cardiac or cerebrovascular disease were more likely to be on best medical therapy.

Natural language processing of clinical notes for identification of critical limb ischemia

Background

Critical limb ischemia (CLI) is a complication of advanced peripheral artery disease (PAD) with diagnosis based on the presence of clinical signs and symptoms. However, automated identification of cases from electronic health records (EHRs) is challenging due to absence of a single definitive International Classification of Diseases (ICD-9 or ICD-10) code for CLI.

Methods and results

In this study, we extend a previously validated natural language processing (NLP) algorithm for PAD identification to develop and validate a subphenotyping NLP algorithm (CLI-NLP) for identification of CLI cases from clinical notes. We compared performance of the CLI-NLP algorithm with CLI-related ICD-9 billing codes. The gold standard for validation was human abstraction of clinical notes from EHRs. Compared to billing codes the CLI-NLP algorithm had higher positive predictive value (PPV) (CLI-NLP 96%, billing codes 67%, p < 0.001), specificity (CLI-NLP 98%, billing codes 74%, p < 0.001) and F1-score (CLI-NLP 90%, billing codes 76%, p < 0.001). The sensitivity of these two methods was similar (CLI-NLP 84%; billing codes 88%; p < 0.12).

Conclusions

The CLI-NLP algorithm for identification of CLI from narrative clinical notes in an EHR had excellent PPV and has potential for translation to patient care as it will enable automated identification of CLI cases for quality projects, clinical decision support tools and support a learning healthcare system.

Benefits of a Supervised Exercise Program After Lower Limb Bypass Surgery

This study evaluated the efficacy of an exercise program after arterial bypass surgery. Patients undergoing bypass surgery were randomized to a control group (group I), with standard preoperative and postoperative care, or the intervention group (group II) with a supervised exercise program of twice-weekly treadmill assessments from 4 to 10 weeks postoperatively. Ankle-brachial pressure indices and hemodynamic measurements were recorded before and after exercise. The mean increase of maximum walking distance was 3.8% in group I and 175.4% in group II ( P = .001). There was a significant difference between group I and II in the mean ankle-brachial pressure indices increase at the second assessment (0.08 versus 0.23; P = .02). A supervised exercise program leads to better improvement after lower limb bypass surgery for ischemia, but the feasibility of a formal exercise program would be undermined by the reluctance of patients to participate, both in the short-term and long-term.

The effect of exercise on coagulation and fibrinolysis factors in patients with peripheral arterial disease

Peripheral arterial disease is a widely prevalent atherosclerotic occlusive disorder. Symptoms commence with exercise-induced pain in the lower extremities, known as claudication. Despite the fact that exercise has been shown to improve fibrinolytic profile some patients, the effect of exercise on coagulation and fibrinolysis cascades in claudicants has not been comprehensively defined. Literature search in English language yielded 13 studies of exercise on claudicants, including 420 patients. Claudicants tend to have a higher coagulation activity at rest compared to healthy individuals, a trend that persists even after exercise. Post-exercise coagulation activity of claudicants is increased when compared to their respective baseline levels, but it is so in a non-consistent manner. From the available data, it has been suggested that claudicants have a functional and effective fibrinolytic mechanism in place, operating continuously at a relatively higher activity level compared to healthy individuals. Fibrinolysis seems to be activated by exercise; a positive outcome with a prolonged effect as shown by a few of the studies. A final conclusion whether coagulation or fibrinolysis activity is affected mostly by exercise type and intensity in claudicants could not be answered. All conclusions regarding the effect of exercise on the coagulation and fibrinolysis mechanisms should be taken under cautious consideration, due to the limited number of studies, the small number of patients and the different exercise strategies employed in each study. Further randomized studies with similar exercise protocols could provide safer conclusions in the future.

‘You can’t walk with cramp!’ A qualitative exploration of individuals’ beliefs and experiences of walking as treatment for intermittent claudication

Walking is an effective but underused treatment for intermittent claudication. This qualitative study explored people’s experiences of and beliefs about their illness and walking with intermittent claudication. Using the Framework method, semi-structured in-depth interviews included 19 individuals with intermittent claudication, and were informed by the Theory of Planned Behaviour and Common Sense Model of Illness Representations. Walking was overlooked as a self-management opportunity, regardless of perceptions of intermittent claudication as severe or benign. Participants desired tailored advice, including purposeful and vigorous exercise, and the potential outcome of walking. Uncertainties about their illness and treatment may explain low walking participation among people with intermittent claudication.

Reconstruction of "unreconstructable" critical limb ischemia with hybrid techniques

This case describes the surgical repair of critical limb ischemia in a patient with diffuse multilevel peripheral arterial disease. It demonstrates the value of patient-specific approaches that employ hybrid endovascular and open surgical techniques to reconstruct blood flow in patients who are not ideal candidates for traditional revascularization. We detail a technique that combines endarterectomy, femoropopliteal bypass, angioplasty, and stenting. This case suggests that innovative hybrid approaches can be used to achieve limb salvage in some patients with multilevel peripheral vascular disease who would otherwise undergo primary amputation.

Comparing Supervised Exercise Therapy to Invasive Measures in the Management of Symptomatic Peripheral Arterial Disease

Peripheral arterial disease (PAD) is associated with considerable morbidity and mortality. Consensus rightly demands the incorporation of supervised exercise training (SET) into PAD treatment protocols. However, the exact role of SET particularly its relationship with intervention requires further clarification. While supervised exercise is undoubtedly an excellent tool in the conservative management of mild PAD its use in more advanced disease as an adjunct to open or endovascular intervention is not clearly defined. Indeed its use in isolation in this cohort is incompletely reported. The aim of this review is to clarify the exact role of SET in the management of symptomatic PAD and in particular to assess its role in comparison with or as an adjunct to invasive intervention. A systematic literature search revealed a total 11 randomised studies inclusive of 969 patients. All studies compared SET and intervention with monotherapy. Study results suggest that exercise is a complication-free treatment. Furthermore, it appears to offer significant improvements in patients walk distances with a combination of both SET and intervention offering a superior walking outcome to monotherapy in those requiring invasive measures.

Direct Revascularization With the Angiosome Concept for Lower Limb Ischemia: A Systematic Review and Meta-Analysis

The angiosome concept provides practical information regarding the vascular anatomy of reconstructive and vascular surgery for the treatment of peripheral arterial occlusive disease and, particularly, critical lower limb ischemia.The aim of the study was to confirm the efficacy of direct revascularization with the angiosome concept (DR) for lower limb ischemia.Complementary manual searches were performed through the Pubmed, Cochrane Library, and EMBASE databases.We searched all randomized and nonrandomized studies (NRSs) comparing DR with indirect revascularization (IR) (without the angiosome concept) for lower limb ischemia. Only 9 nonrandomized controlled retrospective cohort studies were found and included. Trials published in any language were included.Primary endpoints were time to limb amputation and time to wound healing. Data extraction and trial quality assessment were performed by two authors independently. A third author was consulted for disagreements settlement and quality assurance.Five NRSs involving 779 lower limbs revealed that DR significantly improved the overall survival of limbs (hazard ratio [HR] 0.61; 95% confidence interval [CI] = 0.46-0.80; P < 0.001; I = 0%). In addition, DR significantly improved time to wound healing (HR 1.38; 95% CI = 1.13-1.69; P = 0.002; I = 0%, in 5 studies including 605 limbs).All included studies were retrospective comparative studies, and no consensus was obtained in describing wound conditions in the included studies.Our results suggested that treatment of lower limb ischemia using DR is more effective in salvaging limbs and healing wounds than IR is. Additional randomized controlled studies are necessary to confirm these results.

Intratester and Intertester Reliability of Toe Pressure Measurements in People with and Without Diabetes Performed by Podiatric Physicians

BACKGROUND

Toe pressures and the toe brachial index (TBI) represent possible screening tools for peripheral arterial disease; however, limited evidence is available regarding their reliability. The aim of this study was to determine intratester and intertester reliability of toe systolic pressure and the TBI in participants with and without diabetes performed by podiatric physicians.

METHODS

Two podiatric physicians performed toe and brachial pressure measurements on 80 participants, 40 with and 40 without diabetes, during two testing sessions using photoplethysmography and Doppler probe. Intraclass correlation coefficients (ICCs) and 95% limits of agreement were determined.

RESULTS

In people with diabetes, intratester reliability of toe pressure measurement was excellent for both testers (ICCs, 0.84 and 0.82). Reliability of the TBI was good (ICCs, 0.72 and 0.75) and brachial pressure fair (ICCs, 0.43 and 0.55). The intertester reliability of toe pressure (ICC, 0.82) and the TBI (ICC, 0.80) was excellent. Intertester reliability of brachial pressure was reduced in people with diabetes (ICC, 0.49). In age-matched participants, intratester reliability of toe pressure measurement was excellent for both testers (ICCs, 0.83 and 0.87), and reliability of the TBI (ICCs, 0.74 and 0.80) and brachial pressure (ICCs, 0.73 and 0.78) was good to excellent. Intertester reliability of toe pressure (ICC, 0.84), the TBI (ICC, 0.81), and brachial pressure (ICC, 0.77) was excellent.

CONCLUSIONS

Toe pressures and the TBI demonstrated excellent reliability in people with and without diabetes and can be an effective component of lower-extremity vascular screening. However, wide limits of agreement relative to blood pressure values for both cohorts indicate that results should be interpreted with caution.

Serial optical coherence tomography assessments at 2- and 4-month follow-up after paclitaxel-eluting stenting of the superficial femoral artery

A 71-year-old man underwent endovascular therapy (EVT) with a paclitaxel-eluting stent in superficial femoral artery (SFA). Optical coherence tomography (OCT) of SFA at 2 months after EVT revealed that several struts were not covered with neointima. Moreover, some mural thrombi were detected within the stent. Although OCT revealed that the frequency of stent strut coverage was improved at the 4-month follow-up, uncovered stent strut still remained and some mural thrombi were observed within the stent even at 4 months after EVT. This is the first report to demonstrate the vascular response after paclitaxel-eluting stent placement for the lesion using serial OCT examinations.

Meta-analysis of outcomes of endovascular treatment of infrapopliteal occlusive disease with drug-eluting stents

PURPOSE

To review emerging evidence regarding the use of bare metal (BMS) vs. drug-eluting stents (DES) in the treatment of infrapopliteal occlusive disease.

METHODS

A systematic review of the literature was undertaken to identify all studies comparing stent treatments of infragenicular vessels in patients with chronic lower limb ischemia. Validated methods to assess the methodological quality of the included studies were applied. Outcome data were pooled, and combined overall effect sizes were calculated using fixed or random effects models. The search identified 4 randomized clinical trials and 2 observational studies reporting on 544 patients (287 treated with DES and 257 treated with BMS). Data are presented as the odds ratio (OR) with 95% confidence interval (CI) and the number-needed-to-treat (NNT).

RESULTS

Primary patency, freedom from target lesion revascularization, and clinical improvement at 1 year were significantly higher in the DES recipients compared to patients treated with BMS (OR 4.511, 95% CI 2.897 to 7.024, p<0.001, NNT 3.5; OR 3.238, 95% CI 2.019 to 5.192, p<0.001, NNT 6.0; and OR 1.792, 95% CI 1.039 to 3.090, p=0.036, NNT 7.3, respectively). No significant differences in limb salvage and overall survival at 1 year were identified between the groups (OR 2.008, 95% CI 0.722 to 5.585, p=0.181; OR 1.262, 95% CI 0.605 to 2.634, p=0.535, respectively). Sensitivity analyses investigating the potential effects of study design and type of DES on the combined outcome estimates validated the results.

CONCLUSION

Our analysis has demonstrated superior short-term results with DES compared with BMS, expressed by increased patency and freedom from target lesion revascularization. The influence of this finding on clinical surrogate endpoints, such as limb salvage, remains unknown.

Angiosome-targeted revascularisation in diabetic foot ulcers

Peripheral vascular disease is a common complication of type 2 diabetes and is often more severe and diffuse than in non-diabetic individuals with a higher risk of major amputations in the lower limbs. Diabetic foot revascularisation using both traditional bypass surgery and endovascular therapy are often burdened by the failure and the inevitable subsequent massive amputation. In this study, we examined the clinical response of diabetic patients with critical limb ischaemia and extended ischaemic wounds, treated with a new angiosome-based revascularisation technique. In a 3-year period, nine diabetic patients with imminent amputation threatening and foot ulcers with no feasible arterial revascularisation options were treated by the angiosome-based surgical technique by means of deep vein arterialisation. The postoperative tcPO2 evaluation showed a mean increase in the cutaneous oxygen tension in all patients treated. The overall survival rates were 88·88%, 88·88% and 77·77% at 12, 24 and 36 months, respectively. Limb salvage was 100% at 1 year and steady at 88·88% thereafter. Surgical deep venous arterialisation might be considered as an extreme alternative to attempt tissue preservation in limbs unfit for conventional arterial revascularisations. This technique would give advantages to the patients in terms of better compliance to the minor amputations and thus avoiding major limb amputations.

Naftidrofuryl for intermittent claudication

BACKGROUND

Lifestyle changes and cardiovascular prevention measures are a primary treatment for intermittent claudication (IC). Symptomatic treatment with vasoactive agents (Anatomic Therapeutic Chemical Classification (ATC) for medicines from the World Health Organisation class CO4A) is controversial.

OBJECTIVES

To evaluate evidence on the efficacy and safety of oral naftidrofuryl (ATC CO4 21) versus placebo on the pain-free walking distance (PFWD) of people with IC by using a meta-analysis based on individual patient data (IPD).

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched October 2012) and CENTRAL (2012, Issue 9).For the original review the authors handsearched the European Journal of Vascular and Endovascular Surgery (1984 to 1994) and checked relevant bibliographies. They contacted the registration holder of naftidrofuryl and the authors of identified trials for any unpublished data.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) with low or moderate risk of bias for which the IPD were available.

DATA COLLECTION AND ANALYSIS

We collected data from the electronic data file or from the case report form and checked the data by a statistical quality control procedure. All randomized patients were analyzed following the intention-to-treat (ITT) principle. The geometric mean of the relative improvement in PFWD was calculated for both treatment groups in all identified studies.The effect of the drug was assessed compared with placebo on final walking distance (WDf) using multilevel and random-effect models and adjusting for baseline walking distance (WD0). For the responder analysis, therapeutic success was defined as an improvement of walking distance of at least 50%.

MAIN RESULTS

We included seven studies in the IPD (n = 1266 patients). One of these studies (n = 183) was only used in the sensitivity analysis so that the main analysis included 1083 patients. The ratio of the relative improvement in PFWD (naftidrofuryl compared with placebo) was 1.37 (95% confidence interval (CI) 1.27 to 1.49, P < 0.001). The absolute difference in responder rate, or proportion successfully treated, was 22.3% (95% CI 17.1% to 27.6%). The calculated number needed to treat was 4.5 (95% CI 3.6 to 5.8).

AUTHORS' CONCLUSIONS

Oral naftidrofuryl has a statistically significant and clinically meaningful, although moderate, effect of improving walking distance in the six months after initiation of therapy for people with intermittent claudication. Access by researchers to data from RCTs that are suitable for IPD analysis should be possible through repositories of data from pharmacological trials. Regular formal appraisal of the balance of risk and benefit is needed for older pharmaceutical products.

Statistical security for Social Security

The financial viability of Social Security, the single largest U.S. government program, depends on accurate forecasts of the solvency of its intergenerational trust fund. We begin by detailing information necessary for replicating the Social Security Administration's (SSA's) forecasting procedures, which until now has been unavailable in the public domain. We then offer a way to improve the quality of these procedures via age- and sex-specific mortality forecasts. The most recent SSA mortality forecasts were based on the best available technology at the time, which was a combination of linear extrapolation and qualitative judgments. Unfortunately, linear extrapolation excludes known risk factors and is inconsistent with long-standing demographic patterns, such as the smoothness of age profiles. Modern statistical methods typically outperform even the best qualitative judgments in these contexts. We show how to use such methods, enabling researchers to forecast using far more information, such as the known risk factors of smoking and obesity and known demographic patterns. Including this extra information makes a substantial difference. For example, by improving only mortality forecasting methods, we predict three fewer years of net surplus, $730 billion less in Social Security Trust Funds, and program costs that are 0.66% greater for projected taxable payroll by 2031 compared with SSA projections. More important than specific numerical estimates are the advantages of transparency, replicability, reduction of uncertainty, and what may be the resulting lower vulnerability to the politicization of program forecasts. In addition, by offering with this article software and detailed replication information, we hope to marshal the efforts of the research community to include ever more informative inputs and to continue to reduce uncertainties in Social Security forecasts.

How 'preventable' are lower extremity amputations? A qualitative study of patient perceptions of precipitating factors

PURPOSE

Clinicians commonly believe that lower extremity amputations are potentially preventable with coordinated care and motivated patient self-management. We used in-depth interviews with recent amputees to assess how patients viewed their initial amputation risk and causes.

METHOD

We interviewed 22 patients at a rehabilitation hospital 2-6 weeks after an incident amputation. We focused on patients' representations of amputation cause and methods of coping with prior foot and leg symptoms.

RESULTS

Patients reported unexpected onset and rapid progression of ulceration, infection, progressive vascular disease, foot trauma and complications of comorbid illness as precipitating events. Fateful delays of care were common. Many had long histories of painful prior treatments. A fatalistic approach to self-management, difficulties with access and communication with providers and poor understanding of medical conditions were common themes. Few patients seemed aware of the role of smoking as an amputation risk factor.

CONCLUSIONS

Most patients felt out of control and had a poor understanding of the events leading to their initial amputations. Prevention of subsequent amputations will require rehabilitation programs to address low health literacy and psychosocial obstacles to self-management.

Systematic drug repositioning based on clinical side-effects

Drug repositioning helps fully explore indications for marketed drugs and clinical candidates. Here we show that the clinical side-effects (SEs) provide a human phenotypic profile for the drug, and this profile can suggest additional disease indications. We extracted 3,175 SE-disease relationships by combining the SE-drug relationships from drug labels and the drug-disease relationships from PharmGKB. Many relationships provide explicit repositioning hypotheses, such as drugs causing hypoglycemia are potential candidates for diabetes. We built Naïve Bayes models to predict indications for 145 diseases using the SEs as features. The AUC was above 0.8 in 92% of these models. The method was extended to predict indications for clinical compounds, 36% of the models achieved AUC above 0.7. This suggests that closer attention should be paid to the SEs observed in trials not just to evaluate the harmful effects, but also to rationally explore the repositioning potential based on this “clinical phenotypic assay”.

Prevalence of peripheral arterial disease and related risk factors in Turkish elders

Background

It is known that prevalence of peripheral arterial disease being a widespread atherosclerotic vascular disease increases by age. On the other hand, no comprehensive study showing the prevalence of peripheral arterial disease in Turkish elders is seen. In this study, it is aimed to assess prevalence of peripheral arterial disease and related risk factors in Turkish elders in primary health center.

Methods

507 elderly staying at Narlidere Geriatric Care Center and Residential Home and accepting to participate in the study were included in the study. Epidemiological data for diagnosis of peripheral arterial disease, risk factors, findings of physical examination and ankle brachial index measurements were assessed in the study. Data were analyzed in terms of prevalence of peripheral arterial disease, age and gender relation and other cardiovascular risk factors.

Results

Of the participants, 317 (62.5%) were female. The mean age was 77.61 ± 6.93 years (62-102). The most wide-spread chronic diseases in elderly included hypertension, coronary artery disease, hyperlipidemia and Type 2 DM, respectively. On the other hand, only 7 (1.4%) elderly were diagnosed with peripheral arterial disease. The number of elderly ABI of whom was measured as < 0.90 and sent to cardiovascular surgery polyclinic with the diagnosis of peripheral arterial disease was assessed as 30 (5.9%). Intermittent claudication was seen in about half of these patients.

Conclusions

Peripheral arterial disease is expected to be seen prevailing in elderly. However, it was determined at very low rate before the study due to the fact that the disease cannot be diagnosed clinically especially in early-period. Peripheral arterial disease determined in the study is lower than expected as per the age group. This can be associated with practices of geriatrics nursing and family practice including continuous care to reduce cardiovascular risk factors of patients staying at the unit.

Peripheral arterial disease--what do we need to know?

Peripheral artery disease (PAD) results from progressive narrowing of arteries secondary to atherosclerosis and is defined as an Ankle Brachial Index of <0.9. PAD is highly prevalent and is an increasing burden on both the economy and the patient, especially given the rapid shift in demographics in the United States. Despite its prevalence and association with cardiovascular disease, PAD is still underdiagnosed and undertreated. This may, in part, be related to lack of recognition from the physician's side or paucity of evidence from clinical trials. It has been shown that medical therapy approved for cardiovascular disease is effective in the treatment of PAD and decreases cardiovascular events. Various revascularization strategies are also available for improving symptoms and quality of life in these patients, yet they are underutilized. In an attempt to increase its recognition, PAD has been considered a coronary artery disease equivalent. This article reviews the diagnosis and management of PAD. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.

To screen or not to screen for peripheral arterial disease in subjects aged 80 and over in primary health care: a cross-sectional analysis from the BELFRAIL study

BACKGROUND

Peripheral arterial disease (PAD) is common in older people. An ankle-brachial index (ABI) < 0.9 can be used as an indicator of PAD. Patients with low ABI have increased mortality and a higher risk of serious cardiovascular morbidity. However, because 80% of the patients are asymptomatic, PAD remains unrecognised in a large group of patients. The aims of this study were 1) to examine the prevalence of reduced ABI in subjects aged 80 and over, 2) to determine the diagnostic accuracy of the medical history and clinical examination for reduced ABI and 3) to investigate the difference in functioning and physical activity between patients with and without reduced ABI.

METHODS

A cross-sectional study embedded within the BELFRAIL study. A general practitioner (GP) centre, located in Hoeilaart, Belgium, recruited 239 patients aged 80 or older. Only three criteria for exclusion were used: urgent medical need, palliative situation and known serious dementia. The GP recorded the medical history and performed a clinical examination. The clinical research assistant performed an extensive examination including Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS-15), Activities of Daily Living (ADL), Tinetti test and the LASA Physical Activity Questionnaire (LAPAQ). ABI was measured using an automatic oscillometric appliance.

RESULTS

In 40% of patients, a reduced ABI was found. Cardiovascular risk factors were unable to identify patients with low ABI. A negative correlation was found between the number of cardiovascular morbidities and ABI. Cardiovascular morbidity had a sensitivity of 65.7% (95% CI 53.4-76.7) and a specificity of 48.6% (95% CI 38.7-58.5). Palpation of the peripheral arteries showed the highest negative predictive value (77.7% (95% CI 71.8-82.9)). The LAPAQ score was significantly lower in the group with reduced ABI.

CONCLUSION

The prevalence of PAD is very high in patients aged 80 and over in general practice. The clinical examination, cardiovascular risk factors and the presence of cardiovascular morbidity were not able to identify patients with a low ABI. A screening strategy for PAD by determining ABI could be considered if effective interventions for those aged 80 and over with a low ABI become available through future research.

Nurse-led rapid access vascular examination clinic triage reduces inappropriate referrals for peripheral arterial disease

INTRODUCTION

Peripheral arterial disease causing intermittent claudication (IC) causes decreased quality of life and significant morbidity. We hypothesized that triage of patients referred with suspected IC at a nurse-led rapid access vascular examination (RAVE) clinic would identify those patients requiring vascular surgery assessment.

METHODS

A prospective cohort study was performed. Patients referred with suspected IC were assessed using the Edinburgh claudication questionnaire (ECQ) and arterial Doppler assessment with segmental waveform analysis and calculation of ankle brachial pressure index (ABPI). Data were collected regarding cardiovascular risk and its modification.

RESULTS

Of 451 consecutive patients, mean age was 65 years (range 30-89). Cardiovascular risk factors included: 173/451 (38%) current smokers (162/451 (36%) were ex-smokers); diabetes, 22%; hypertension, 46%; ischaemic heart disease (angina), 29%; dyslipidaemia, 27%. Therapeutic risk modifications included: antiplatelet therapy, 64.4%; lipid-lowering therapy, 57.8%. abnormal ABPI readings were present in 264/451 (59%), with ratio <0.9 in 209/451 (46.3%), >1.3 in 48/451 (10.6%), and incompressible vessels 7/451 (1.5%). Normal ABPI (ratio >0.9 and <1.3, triphasic Doppler waveforms) were found in 187/451 (41%), these patient were considered inappropriate referrals. Considering those patient with PAD diagnosed on abnormal ABPI (<0.9 or >1.3), Doppler waveform analysis was more sensitive and specific than ECQ.

CONCLUSIONS

Diagnosis of IC with clinical history alone is inaccurate in 41 percent of cases, leading to inappropriate referral to vascular surgery. Doppler waveform analysis had excellent sensitivity and specificity for prediction of ABPI <0.9. ABPI measurement in primary care could result in a more efficient use of clinical resources.

Perioperative platelet and monocyte activation in patients with critical limb ischemia

BACKGROUND

Patients with critical limb ischemia (CLI) have a high rate of adverse cardiovascular events, particularly when undergoing surgery. We sought to determine the effect of surgery and vascular disease on platelet and monocyte activation in vivo in patients with CLI.

METHODS

An observational, cross-sectional study was performed at a tertiary referral hospital in the southeast of Scotland. Platelet and monocyte activation were measured in whole blood in patients with CLI scheduled for infrainguinal bypass and compared with matched healthy controls, patients with chronic intermittent claudication, patients with acute myocardial infarction, and those undergoing arthroplasty (n = 30 per group). Platelet and monocyte activation were quantified using flow cytometric assessment of platelet-monocyte aggregation, platelet P-selectin expression, platelet-derived microparticles, and monocyte CD40 and CD11b expression.

RESULTS

Compared with those with intermittent claudication, subjects with CLI had increased platelet-monocyte aggregates (41.7% +/- 12.2% vs 32.6% +/- 8.5%, respectively), platelet microparticles (178.7 +/- 106.9 vs 116.9 +/- 53.4), and monocyte CD40 expression (70.0% +/- 12.2% vs 52.4% +/- 15.2%; P < .001 for all). Indeed, these levels were equivalent (P-selectin, 4.4% +/- 2.0% vs 4.9% +/- 2.2%; P > .05) or higher (platelet-monocyte aggregation, 41.7% +/- 12.2% vs 33.6% +/- 7.0%; P < .05; platelet microparticles, 178.7 +/- 106.9 vs 114.4 +/- 55.0/microL; P < .05) than in patients with acute myocardial infarction. All platelet and monocyte activation markers remained elevated throughout the perioperative period in patients with CLI (P < .01) but not those undergoing arthroplasty.

CONCLUSIONS

Patients undergoing surgery for CLI have the highest level of in vivo platelet and monocyte activation, and these persist throughout the perioperative period. Additional antiplatelet therapy may be of benefit in protecting vascular patients with more severe disease during this period of increased risk.

The use of Matriderm and autologous skin grafting in the treatment of diabetic ulcers: a case report

The aim of our case report was to analyse the results obtained with the Matriderm system and autologous skin grafting for the surgical treatment of diabetic ulcers. We recruited one patient with diabetic ulcers admitted at the Department of Plastic and Reconstructive Surgery, University of Rome 'Tor Vergata'. The patient underwent Matriderm system and autologous skin grafting for diabetic ulcer treatment. After just a single treatment, we obtained reduction in ulcer after 15 days from the surgical treatment. We achieved a reduction in pain and exudate secretion of the ulcer. We noticed an almost complete restoration of the missing volume and good quality of skin. Matriderm system and autologous skin grafting is a simple, safe and feasible technique. This method, when compared with other methods of treatment, is simple, cheap, less time consuming and does not require sophisticated laboratory facilities.

Peripheral Arterial Disease in Community-based Patients with Diabetes in Singapore: Results from a Primary Healthcare Study

Introduction: Peripheral arterial disease (PAD) is an important complication of diabetes mellitus (DM), significantly associated with increased morbidity and mortality secondary to amputations, strokes and coronary artery disease. Information on DM patients with PAD is limited in our ethnically diverse population in Singapore. We aimed to determine the prevalence, risk factors and co-morbidities of PAD in patients managed for DM in the primary care setting. Materials and Methods: A cross-sectional study was conducted among 521 diabetics in 9 of the 18 government-aided clinics in the community. Data including demographics, presence of co-morbidities and vascular risk factors were collected using an interviewer-administered questionnaire, and Ankle-Brachial Index (ABI) was calculated from systolic ankle and brachial pressure measurements. Results: The prevalence of PAD, defined as resting ABI of <0.9 on either leg and/or a history of gangrene or non-traumatic amputation was 15.2% [95% confidence interval (CI), 12.3-18.5]. This prevalence of PAD was higher in patients with pre-existing microvascular and other macrovascular complications. In multivariate analysis, prevalence of PAD was positively associated with increasing age (OR, 1.08; 95% CI, 1.05-1.12), Malay versus Chinese ethnicity (OR, 2.27; 95% CI, 1.09-4.70), low HDL-cholesterol (OR, 1.87; 95% CI, 1.04-3.37), and insulin treatment (OR, 2.98; 95%CI, 1.39-6.36). Conclusion: PAD is an important cause of concern among patients with diabetes, with a high prevalence which further increases with increasing age and duration of DM, and exhibits ethnic variation. Risk factors identified in this study may improve early identification of PAD, allowing for prompt interventions, with a potential to reduce long-term morbidity and mortality. Key words: Ethnic variation, Macrovascular complications, Risk factors