Clinimetrics of performance-based functional outcome measures for vascular amputees: A systematic review.

BACKGROUND: Objective physical performance-based outcome measures (PerBOMs) are essential tools for the holistic management of people who have had an amputation due to vascular disease. These people are often non-ambulatory, however it is currently unclear which PerBOMs are high quality and appropriate for those who are either ambulatory or non-ambulatory. RESEARCH QUESTION: Which PerBOMs have appropriate clinimetric properties to be recommended for those who have had amputations due to vascular disease ('vascular amputee')? DATA SOURCES: MEDLINE, CINAHL, EMBASE, EMCARE, the Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL) and Scopus databases were searched for the terms: "physical performance" or "function", "clinimetric properties", "reliability", "validity", "amputee" and "peripheral vascular disease" or "diabetes". REVIEW METHODS: A systematic review of PerBOMs for vascular amputees was performed following COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology and PRISMA guidelines. The quality of studies and individual PerBOMs was assessed using COSMIN risk of bias and good measurement properties. Overall PerBOM quality was evaluated with a modified GRADE rating. Key clinimetric properties evaluated were reliability, validity, predictive validity and responsiveness. RESULTS: A total of 15,259 records were screened. Forty-eight studies (2650 participants) were included: 7 exclusively included vascular amputees only, 35 investigated validity, 20 studied predictive validity, 23 investigated reliability or internal consistency and 7 assessed responsiveness. Meta-analysis was neither possible nor appropriate for this systematic review in accordance with COSMIN guidelines, due to heterogeneity of the data. Thirty-four different PerBOMs were identified of which only 4 are suitable for non-ambulatory vascular amputees. The Amputee Mobility Predictor no Prosthesis (AMPnoPro) and Transfemoral Fitting Predictor (TFP) predict prosthesis use only. PerBOMs available for assessing physical performance are the One-Leg Balance Test (OLBT) and Basic Amputee Mobility Score (BAMS). CONCLUSION: At present, few PerBOMs can be recommended for vascular amputees. Only 4 are available for non-ambulatory individuals: AMPnoPro, TFP, OLBT and BAMS.

The Impact of the COVID-19 Pandemic on a Dedicated Vascular Emergency Clinic.

BACKGROUND: Vascular Emergency Clinics (VEC) improve patient outcomes in chronic limb-threatening ischemia (CLTI). They provide a "1 stop" open access policy, whereby "suspicion of CLTI" by a healthcare professional or patient leads to a direct review. We assessed the resilience of the outpatient VEC model to the first year of the coronavirus disease (COVID-19) pandemic. METHODS: A retrospective review of a prospectively maintained database of all patients assessed in our VEC for lower limb pathologies between March 2020 and April 2021 was performed. This was cross-referenced to national and loco-regional Governmental COVID-19 data. Individuals with CLTI were further analysed to determine Peripheral Arterial Disease-Quality Improvement Framework compliance. RESULTS: Seven hundred and ninety one patients attended for 1,084 assessments (Male n = 484, 61%; Age 72.5 ± standard deviation 12.2 years; White British n = 645, 81.7%). In total, 322 patients were diagnosed with CLTI (40.7%). A total of 188 individuals (58.6%) underwent a first revascularization strategy (Endovascular n = 128, 39.8%; Hybrid n = 41, 12.7%; Open surgery n = 19, 5.9%; Conservative n = 134, 41.6%). Major lower limb amputation rate was 10.9% (n = 35) and mortality rate was 25.8% (n = 83) at 12 months of follow-up. Median referral to assessment time was 3 days (interquartile range: 1-5). For the nonadmitted patient with CLTI, the median assessment to intervention was 8 days (interquartile range: 6-15) and median referral to intervention time of 11 days (11-18). CONCLUSIONS: The VEC model has demonstrated strong resilience to the COVID-19 pandemic with rapid treatment timelines maintained for patients with CLTI.

Effect of high-pain versus low-pain structured exercise on walking ability in people with intermittent claudication: meta-analysis.

BACKGROUND: The aim was to determine the comparative benefits of structured high-pain exercise, structured low-pain exercise, and usual-care control, to identify which has the largest effect on walking ability in people with intermittent claudication (IC). METHODS: A network meta-analysis was undertaken to assess two outcomes: pain-free walking ability (PFWA) and maximal walking ability (MWA). Nine electronic databases were searched. Trials were included if they were: RCTS; involved adults with IC; had at least two of the following arms-structured low-pain exercise, structured high--pain exercise or usual-care control; and a maximal or pain-free treadmill walking outcome. RESULTS: Some 14 trials were included; results were pooled using the standardized mean difference (MD). Structured low-pain exercise had a significant large positive effect on MWA (MD 2.23, 95 percent c.i. 1.11 to 3.35) and PFWA (MD 2.26, 1.26 to 3.26) compared with usual-care control. Structured high-pain exercise had a significant large positive effect on MWA (MD 0.95, 0.20 to 1.70) and a moderate positive effect on PFWA (0.77, 0.01 to 1.53) compared with usual-care control. In an analysis of structured low- versus high pain exercise, there was a large positive effect in favour of low-pain exercise on MWA (MD 1.28, -0.07 to 2.62) and PFWA (1.50, 0.24 to 2.75); however, this was significant only for PFWA. CONCLUSION: There is strong evidence in support of use of structured high-pain exercise, and some evidence in support of structured low-pain exercise, to improve walking ability in people with IC compared with usual-care control (unstructured exercise advice).

The Impact of Anemia on One-Year Amputation-Free Survival in Patients Undergoing Revascularization for Chronic Limb-Threatening Ischemia: A Retrospective Cohort Study.

BACKGROUND: Anemia is potentially associated with increased morbidity and mortality following vascular surgery procedures. This study investigated whether peri-procedural anemia is associated with reduced 1-year amputation-free survival (AFS) in patients undergoing revascularization for chronic limb-threatening ischemia (CLTI). METHODOLOGY: A retrospective analysis of patients diagnosed with CLTI between February 2018-February 2019, who subsequently underwent revascularization, was conducted. Hemoglobin concentration measured at index assessment was recorded and stratified by WHO criteria. Subsequent peri-procedural red blood cell transfusions (RBC) were also recorded. The primary outcome was 1-year AFS. Kaplan Meier survival analysis and Cox's proportional hazard modelling were conducted to assess the effect of anemia and peri-procedure transfusion on outcomes. RESULTS: 283 patients were analyzed, of which 148 (52.3%) were anemic. 53 patients (18.7%) underwent RBC transfusion. Patients with anemia had a significantly lower 1-year AFS (64.2% vs. 78.5%, P = 0.009). A significant difference in 1-year AFS was also observed based upon anemia severity (P = 0.008) and for patients who received RBC transfusion (45.3% vs 77.0%, P < 0.001). On multivariable analysis, moderately severe anemia was independently associated with increased risk of major amputation/death (aHR 1.90, 95% CI 1.06-3.38, P = 0.030). After adjusting for severity of baseline anemia, peri-procedural RBC transfusion was associated with a significant increase in the combined risk of major amputation/death (aHR 3.15, 95% CI 1.91-5.20, P < 0.001). CONCLUSION: Moderately severe peri-procedural anemia and subsequent RBC transfusion are independently associated with reduced 1-year AFS in patients undergoing revascularization for CLTI. Future work should focus on investigating alternative measures to managing anemia in this cohort.

The Relationship Between Obesity and Amputation-free Survival in Patients Undergoing Lower-limb Revascularisation for Chronic Limb-threatening Ischaemia: A Retrospective Cohort Study.

BACKGROUND: The obesity paradox is a well-documented phenomenon in cardiovascular disease, however it remains poorly understood. We aimed to investigate the relationship between body mass (as measured by body mass index [BMI]) and 1-year amputation-free survival (AFS) for patients undergoing lower limb revascularisation for chronic limb-threatening ischaemia (CLTI). METHODS: A retrospective analysis was undertaken of all consecutive patients undergoing lower limb revascularisation for CLTI at the Leicester Vascular Institute between February 2018-19. Baseline demographics and outcomes were collected using electronic records. BMI was stratified using the World Health Organization criteria. One-year AFS (composite of major amputation/death) was the primary outcome. Kaplan-Meier survival analysis and adjusted Cox's proportional hazard models were used to compare groups to patients of normal mass. RESULTS: One-hundred and ninety patients were included. Overall, no difference was identified in 1-year AFS across all groups (pooled P = 0.335). Compared to patients with normal BMI (n = 66), obese patients (n = 43) had a significantly lower adjusted combined risk of amputation/death (aHR 0.39, 95% CI 0.16-0.92, P = 0.032), however no significant differences were observed for overweight (aHR 0.89, 95% CI 0.47-1.70, P = 0.741), morbidly obese (aHR 1.15, 95% CI 0.41-3.20, P = 0.797) and underweight individuals (aHR 1.86, 95% CI 0.56-6.20, P = 0.314). CONCLUSIONS: In the context of CLTI, obesity is potentially associated with favourable amputation-free survival at 1 year, compared to normal body mass. The results of this study support the notion of an obesity paradox existing within CLTI and question whether current guidance on weight management requires a more patient-specific approach.

Understanding variations in reported epidemiology of major lower extremity amputation in the UK: a systematic review.

OBJECTIVE: Estimate the prevalence/incidence/number of major lower extremity amputations (MLEAs) in the UK; identify sources of routinely collected electronic health data used; assess time trends and regional variation; and identify reasons for variation in reported incidence/prevalence of MLEA. DESIGN: Systematic review and narrative synthesis. DATA SOURCES: Medline, Embase, EMcare, CINAHL, The Cochrane Library, AMED, Scopus and grey literature sources searched from 1 January 2009 to 1 August 2021. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Reports that provided population-based statistics, used routinely collected electronic health data, gave a measure of MLEA in adults in the general population or those with diabetes in the UK or constituent countries were included. DATA EXTRACTION AND SYNTHESIS: Data extraction and quality assessment using the Joanna Briggs Institute Critical Appraisal Instruments were performed by two reviewers independently. Due to considerable differences in study populations and methodology, data pooling was not possible; data were tabulated and narratively synthesised, and study differences were discussed. RESULTS: Twenty-seven reports were included. Incidence proportion for the general population ranged from 8.2 to 51.1 per 100 000 and from 70 to 291 per 100 000 for the population with diabetes. Evidence for trends over time was mixed, but there was no evidence of increasing incidence. Reports consistently found regional variation in England with incidence higher in the north. No studies reported prevalence. Differences in database use, MLEA definition, calculation methods and multiple procedure inclusion which, together with identified inaccuracies, may account for the variation in incidence. CONCLUSIONS: UK incidence and trends in MLEA remain unclear; estimates vary widely due to differences in methodology and inaccuracies. Reasons for regional variation also remain unexplained and prevalence uninvestigated. International consensus on the definition of MLEA and medical code list is needed. Future research should recommend standards for the reporting of such outcomes and investigate further the potential to use primary care data in MLEA epidemiology. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020165592.

Associations of Clinical Frailty with Severity of Limb Threat and Outcomes in Chronic Limb-threatening Ischaemia.

OBJECTIVE: Investigate the relationship of frailty and severity of chronic limb-threatening ischaemia (CLTI), and their comparative associations with one-year outcomes, in patients presenting to a vascular limb salvage (VaLS) clinic. METHODS: This retrospective cohort study utilised data collected from a prospectively maintained VaLS clinic database. Patients aged ≥50 presenting to the VaLS clinic with CLTI between February 2018 and April 2019 were included. Frailty was measured using the Clinical Frailty Scale (CFS) and limb threat severity by the Wound, Ischaemia, and foot Infection (WIfI) score. Excessive polypharmacy was defined as ≥10 medications. Anticholinergic burden (ACB) score and Charlson comorbidity index (CCI) were calculated for all patients. The primary outcome measure was a composite endpoint of death or amputation at one-year. Associations with outcome were assessed using Cox regression and reported as hazards ratios (HR) with 95% confidence intervals (CI). RESULTS: A total of 198 patients were included, with CFS scores available for 190 patients. 98 patients (52%) were frail (CFS ≥5). 127 patients (67%) initially underwent endovascular revascularisation. Excessive polypharmacy was common (55 patients; 28%). Frailty was associated with increased WIfI stage (P = 0.025) as well as age, female sex, CCI score, number of medications, excessive polypharmacy but not ACB score. Frail patients were more frequently managed non-operatively (P = 0.017). Frailty (HR 1.91; 95% CI 1.09, 3.34; P = 0.024) and WIfI stage 4 (HR 3.29; 95%CI 1.23, 8.80; P = 0.018) were associated with death or amputation on univariable analysis. WIfI stage 4 (HR 2.80; 95%CI 1.04, 7.57; P = 0.042) and CCI score (HR 1.21; 95%CI 1.03, 1.41; P = 0.015), but not frailty (HR 1.25; 95%CI 0.67, 2.33; P = 0.474), were independently associated with death or amputation on multivariable analysis. CONCLUSIONS: Frailty is highly prevalent among CLTI patients and related to severity of limb threat. The CFS may be a useful adjunct to patient risk assessment in CLTI.

Does the Introduction of a Vascular Limb Salvage Service Improve One Year Amputation Outcomes for Patients with Chronic Limb-Threatening Ischaemia?

OBJECTIVE: Vascular limb salvage services are recommended by the Global Vascular Guidelines to help improve outcomes for patients with chronic limb-threatening ischaemia (CLTI), although their description within the literature is limited. This study reports the 12 month outcomes for an outpatient based vascular limb salvage (VaLS) clinic. METHODS: An analysis of a prospectively maintained database, involving all consecutive patients diagnosed with CLTI within the VaLS clinic from February 2018-February 2019, was undertaken. Data were compared with two comparator cohorts, identified from coding data: 1) patients managed prior to the clinic, between May 2017 and February 2018 (Pre-Clinic [PC]); and 2) patients managed outside of clinic, between February 2018 and February 2019 (Alternative Pathways [AP]). Freedom from major amputation at 12 months was the primary outcome. Kaplan-Meier plots and adjusted Cox's proportional hazard models (aHR) were used to compare outcomes. RESULTS: Five hundred and sixty-six patients (VaLS 158, AP 173, PC 235) were included (median age 74 years). Patients managed within the VaLS cohort were statistically significantly more likely to be free from major amputation (90.5%) compared with both the AP (82.1%, aHR 0.52, 95% confidence interval [CI] 0.28 - 0.98, p = .041) and the PC (80.0%; aHR 0.50, 95% CI 0.28 - 0.91, p = .022) cohorts at 12 months, after adjustment for age, disease severity, and presence of diabetes. CONCLUSION: This study supports the recommendations of the Global Vascular Guidelines that vascular limb salvage clinics may improve the rate of major amputation. Furthermore, the study provides a reproducible service model that delivers timely vascular assessment in an ambulatory setting. Further evaluation is required to assess longer term outcomes.

Prevalence of Cognitive Impairment in Individuals with Vascular Surgical Pathology: a Systematic Review and Meta-Analysis.

OBJECTIVE: A significant proportion of vascular surgery patients may have undiagnosed cognitive impairment; however, its true prevalence and impact on outcomes are unknown. The aim of this review was to estimate the prevalence of cognitive impairment among individuals with clinically significant vascular surgical pathology and investigate its associations with post-operative outcomes in those undergoing vascular surgery. METHODS: MEDLINE, EMBASE, EMCare, CINAHL, PsycINFO, and Scopus were searched for relevant studies. Included studies assessed cognitive function among individuals with either symptomatic vascular surgical pathology, or disease above threshold for intervention, using a validated cognitive assessment tool. The primary outcome measure was prevalence of cognitive impairment. Secondary outcomes included incidence of post-operative delirium (POD). Two reviewers independently extracted relevant study data and assessed risk of bias (ROBINS-E or RoB 2 tool). Prevalence (%) of cognitive impairment was calculated for individual studies and presented with 95% confidence intervals (CI). Prevalence data from comparable studies were pooled using the Mantel-Haenszel method (random effects model) for separate vascular disease types. Certainty of effect estimates was assessed using the GRADE criteria. RESULTS: Twenty-four studies (2 564 participants) were included in the systematic review, and nine studies (1 310 participants) were included in the meta-analyses. The prevalence of cognitive impairment was 61% (95% CI 48 - 74; 391 participants; low certainty) in studies including multiple vascular surgical pathologies, 38% (95% CI 32 - 44; 278 participants; very low certainty) in carotid artery disease, and 19% (95% CI 10 - 33; 641 participants; low certainty) in those with intermittent claudication. Lower cognitive assessment scores were associated with POD (five studies; 841 participants), but data were not suitable for pooling. CONCLUSION: Screening elective vascular surgery patients for cognitive impairment may be appropriate given its high prevalence, and the association of worse cognition with POD, among individuals with clinically significant vascular surgical pathology.

Medical Education in a Post COVID-19 era - remote teaching methods for cardiovascular knowledge and skills.

This article was migrated. The article was marked as recommended. Introduction As traditional clinical teaching faces major obstacles during the COVID-19 pandemic, medical educators look toward remote teaching methods to provide solutions to allow continuation of teaching. Remote methods, teaching delivered other than face-to-face, align with the transformation seen within pedagogy over the last 20 years. Aim The aim of this scoping review was to i) identify existing teaching methods available to remotely teach cardiovascular knowledge or skills and ii) identify if they have been evaluated. Methods A scoping review of the literature was undertaken to synthesise available evidence and examine remote teaching methods for application to undergraduate medical education. Results Forty-two articles were identified which presented remote teaching methods using either teaching based online, computer-programs, digital resources, mobile-phone technology, podcasts, serious gaming, social media or resources to aid self-directed learning. Although results were heterogenous, they gave an indication of the method's usefulness. However, evaluations were not consistent and if they were, would have strengthened the value of the findings. Conclusion Various remote teaching methods are available to replace face-to-face cardiovascular teaching where this is not possible. Evidence for effectiveness and engagement of individual platforms are variable. Given the ongoing COVID-19 pandemic, medical educators should prioritise ongoing evaluation of remote teaching methods and share best practice.

Frailty Factors and Outcomes in Vascular Surgery Patients: A Systematic Review and Meta-analysis.

OBJECTIVE: To describe and critique tools used to assess frailty in vascular surgery patients, and investigate its associations with patient factors and outcomes. BACKGROUND: Increasing evidence shows negative impacts of frailty on outcomes in surgical patients, but little investigation of its associations with patient factors has been undertaken. METHODS: Systematic review and meta-analysis of studies reporting frailty in vascular surgery patients (PROSPERO registration: CRD42018116253) searching Medline, Embase, CINAHL, PsycINFO, and Scopus. Quality of studies was assessed using Newcastle-Ottawa scores (NOS) and quality of evidence using Grading of Recommendations Assessment, Development, and Evaluation criteria. Associations of frailty with patient factors were investigated by difference in means (MD) or expressed as risk ratios (RRs), and associations with outcomes expressed as odds ratios (ORs) or hazard ratios (HRs). Data were pooled using random-effects models. RESULTS: Fifty-three studies were included in the review and only 8 (15%) were both good quality (NOS ≥ 7) and used a well-validated frailty measure. Eighteen studies (62,976 patients) provided data for the meta-analysis. Frailty was associated with increased age [MD 4.05 years; 95% confidence interval (CI) 3.35, 4.75], female sex (RR 1.32; 95% CI 1.14, 1.54), and lower body mass index (MD -1.81; 95% CI -2.94, -0.68). Frailty was associated with 30-day mortality [adjusted OR (AOR) 2.77; 95% CI 2.01-3.81), postoperative complications (AOR 2.16; 95% CI 1.55, 3.02), and long-term mortality (HR 1.85; 95% CI 1.31, 2.62). Sarcopenia was not associated with any outcomes. CONCLUSION: Frailty, but not sarcopenia, is associated with worse outcomes in vascular surgery patients. Well-validated frailty assessment tools should be preferred clinically, and in future research.

Missed Opportunities for Timely Recognition of Chronic Limb Threatening Ischaemia in Patients Undergoing a Major Amputation: A Population Based Cohort Study Using the UK's Clinical Practice Research Datalink.

OBJECTIVE: Opportunities for timely recognition of chronic limb-threatening ischaemia (CLTI) within primary care, such as performing cardiovascular assessment during clinical consultation, are possibly being missed. This study aimed to investigate for potential "missed opportunities" within primary care. METHODS: This was a population based cohort study, using the UK's Clinical Practice Research Datalink (CPRD). Patients undergoing a major amputation for CLTI between 1 January 2000 and 31 December 2016 were included. Primary care consultation and patient clinical data within the one year period prior to amputation were extracted from the CPRD. Dates of last primary care consultation and cardiovascular assessment prior to amputation were evaluated. Timings of latest cardiovascular assessments were stratified into "recent" (7-90 days before amputation) and "late" (> 91 days). RESULTS: In total, 3 260 patients were included. In the year prior to amputation, patients attended a median of 19 (range 9-32) primary care consultations; however, prescription of secondary preventive medications was poor (antiplatelet 49.7%; lipid lowering agent 40.7%). Overall, 2 175 patients (66.7%) attended a primary care consultation 7-30 days before their amputation. However, only 416 (12.8%) underwent a cardiovascular assessment within this period, with 2 073 (63.6%) undergoing no assessment within 90 days of their amputation. Of these 2 073 patients, 1 230 (59.3%) had a primary care consultation 7-30 days before their procedure. Patients undergoing "late" assessment were younger (p = .003), with higher systolic (p = .008) and diastolic (p = .001) blood pressures than those undergoing "recent" assessment. Differences were also observed between assessment timings by deprivation (p = .003) and ethnicity (p = .006). CONCLUSION: Missed opportunities for timely recognition potentially exist and may be related to age, deprivation, and ethnicity. Further work is required to investigate these factors, as well as individual amputations to identify the causes precipitating amputation. Greater emphasis on the medical management of peripheral arterial disease and identifying cardiovascular risk factors in patients who may not fit the "at risk" stereotype, are also required.

Knowledge of peripheral artery disease: What do the public, healthcare practitioners, and trainees know?

This systematic review evaluated the knowledge and awareness of peripheral artery disease (PAD) within the general public (including patients with peripheral vascular disease), nonspecialist healthcare professionals (nsHCP), and trainees (medical students and trainee doctors). Relevant articles were identified from electronic databases using key search terms: 'peripheral artery disease'; 'limb ischaemia'; 'intermittent claudication'; 'knowledge'; 'understanding'; 'public'; 'medical professional'. The heterogeneous results were described narratively. A lack of knowledge and understanding of PAD (disease awareness) were identified in all groups. Among nsHCPs, factors which affect knowledge include the level of training, early clinical exposure and the presence of family members with cardiovascular/vascular disease. Within the general public, knowledge and awareness was improved if a family member/friend had a diagnosis, or following a patient-centred consultation with any HCP. Public campaigns are proven effective in improving disease knowledge/awareness in conditions such as stroke alongside sustained patient education. These may provide future avenues to improve PAD knowledge and awareness, in order to effectively manage risk factors and minimise delayed or missed diagnosis of PAD. (PROSPERO registration number: CRD42018117304).

A systematic review investigating the identification, causes, and outcomes of delays in the management of chronic limb-threatening ischemia and diabetic foot ulceration.

OBJECTIVE: Patients presenting with chronic limb-threatening ischemia and diabetic foot ulceration (DFU) are at high risk of major lower limb amputation. Long-standing concern exists regarding late presentation and delayed management contributing to increased amputation rates. Despite multiple guidelines existing on the management of both conditions, there is currently no accepted time frame in which to enact specialist care and treatment. This systematic review aimed to investigate potential time delays in the identification, referral, and management of both chronic limb-threatening ischemia and DFU. METHODS: A systematic review conforming to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards was performed searching MEDLINE, Embase, The Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature from inception to November 14, 2018. All English-language qualitative and quantitative articles investigating or reporting the identification, causes, and outcomes of time delays within "high-income" countries (annual gross domestic product per person >$15,000) were included. Data were extracted independently by the investigators. Given the clinical crossover, both conditions were investigated together. A study protocol was designed and registered at the International Prospective Register of Systematic Reviews. RESULTS: A total of 4780 articles were screened, of which 32 articles, involving 71,310 patients and 1388 health care professionals, were included. Twenty-three articles focused predominantly on DFU. Considerable heterogeneity was noted, and only 12 articles were deemed of high quality. Only four articles defined a delay, but this was not consistent between studies. Median times from symptom onset to specialist health care assessment ranged from 15 to 126 days, with subsequent median times from assessment to treatment ranging from 1 to 91 days. A number of patient and health care factors were consistently reported as potentially causative, including poor symptom recognition by the patient, inaccurate health care assessment, and difficulties in accessing specialist services. Twenty articles reported outcomes of delays, namely, rates of major amputation, ulcer healing, and all-cause mortality. Although results were heterogeneous, they allude to delays being associated with detrimental outcomes for patients. CONCLUSIONS: Time delays exist in all aspects of the management pathway, which are in some cases considerable in length. The causes of these are complex but reflect poor patient health-seeking behaviors, inaccurate health care assessment, and barriers to referral and treatment within the care pathway. The adoption of standardized limits for referral and treatment times, exploration of missed opportunities for diagnosis, and investigation of novel strategies for providing specialist care are required to help reduce delays.

Outcomes of post-operative duplex ultrasound following arteriovenous fistula formation: A pragmatic single-centre experience.

BACKGROUND: Duplex ultrasound surveillance with pre-emptive treatment of an identified stenosis is increasingly being utilised to help maintain arteriovenous fistula patency. This study aims to determine whether post-operative duplex ultrasound surveillance can improve fistula patency at 12 months and improve the proportion of 'pre-haemodialysis' patients commencing haemodialysis via a usable fistula. METHODS: All arteriovenous fistulae formed between 1st January 2015 and 31st August 2017 in a single, tertiary vascular centre were included. Primary and secondary patency at 12 months, along with the proportion of pre-haemodialysis patients commencing haemodialysis via a usable arteriovenous fistula, were compared between the fistulae undergoing duplex ultrasound surveillance and 'standard practice'. RESULTS: Two hundred forty-one arteriovenous fistulae were created in 216 patients. A higher proportion of brachiobasilic transposition arteriovenous fistula and patients undergoing arteriovenous fistula creation following a previously failed access were identified in the duplex ultrasound surveillance group. Primary patency at 12 months (hazard ratio = 0.43, 95% confidence interval = 0.30-0.61, p < .001) was significantly lower in the duplex ultrasound surveillance group compared with the 'standard practice' group. Despite this, no difference was identified in secondary patency at 12 months (hazard ratio = 1.82, 95% confidence interval = 0.87-3.80, p = .112). No difference was also identified in the proportion of pre-haemodialysis patients starting haemodialysis with a usable arteriovenous fistula (duplex ultrasound surveillance = 65.0% vs standard practice = 77.8%; odds ratio = 0.53, 95% confidence interval 0.58-1.19, p = .279). CONCLUSION: Post-operative duplex ultrasound surveillance following arteriovenous fistula formation is associated with higher rates of post-operative intervention; however, this does not translate into improved secondary patency or the proportion of pre-haemodialysis patients commencing HD via their fistula.

Leg ischaemia management collaboration (LIMb): study protocol for a prospective cohort study at a single UK centre.

INTRODUCTION: Severe limb ischaemia (SLI) is the end stage of peripheral arterial occlusive disease where the viability of the limb is threatened. Around 25% of patients with SLI will ultimately require a major lower limb amputation, which has a substantial adverse impact on quality of life. A newly established rapid-access vascular limb salvage clinic and modern revascularisation techniques may reduce amputation rate. The aim of this study was to investigate the 12-month amputation rate in a contemporary cohort of patients and compare this to a historical cohort. Secondary aims are to investigate the use of frailty and cognitive assessments, and cardiac MRI in risk-stratifying patients with SLI undergoing intervention and establish a biobank for future biomarker analyses. METHODS AND ANALYSIS: This single-centre prospective cohort study will recruit patients aged 18-110 years presenting with SLI. Those undergoing intervention will be eligible to undergo additional venepuncture (for biomarker analysis) and/or cardiac MRI. Those aged ≥65 years and undergoing intervention will also be eligible to undergo additional frailty and cognitive assessments. Follow-up will be at 12 and 24 months and subsequently via data linkage with NHS Digital to 10 years postrecruitment. Those undergoing cardiac MRI and/or frailty assessments will receive additional follow-up during the first 12 months to investigate for perioperative myocardial infarction and frailty-related outcomes, respectively. A sample size of 420 patients will be required to detect a 10% reduction in amputation rate in comparison to a similar sized historical cohort, with 90% power and 5% type I error rate. Statistical analysis of this comparison will be by adjusted and unadjusted logistic regression analyses. ETHICS AND DISSEMINATION: Ethical approval for this study has been granted by the UK National Research Ethics Service (19/LO/0132). Results will be disseminated to participants via scientific meetings, peer-reviewed medical journals and social media. TRIAL REGISTRATION NUMBER: NCT04027244.