Delays to revascularization for patients with chronic limb-threatening ischaemia

Can Common Femoral Artery Doppler Waveform Analysis Reliably Predict Hemodynamically Significant Disease of the Aortoiliac Arteries? A Systematic Review and Meta-Analysis

BACKGROUND

Many guidelines recommend duplex scanning as the first-line investigation for peripheral arterial disease. Qualitative evaluation of the common femoral artery (CFA) waveform provides information regarding the likely presence of significant aortoiliac disease. Certain centers use a "triphasic-and-down" policy, proceeding directly to antegrade endovascular intervention of infra-inguinal disease if the CFA waveform is triphasic. Others mandate cross-sectional imaging regardless of CFA waveform to exclude occult aortoiliac disease. This review aims to analyze the reliability of CFA waveform in excluding significant aortoiliac disease.

METHODS

MEDLINE, Embase, Cochrane library, and reference lists were searched for studies comparing CFA waveform analysis with reference tests assessing aortoiliac disease. Triphasic waveforms were considered "normal", while biphasic/monophasic were considered "abnormal." Meta-analyses using a bivariate model produced pooled diagnostic accuracy metrics, including negative and positive predictive values, sensitivity, and specificity.

RESULTS

Eight studies with 1,139 limbs were included. Where reported, the mean age was 67, 64.4% had claudication and 35.6% had critical limb ischemia, 42.3% were smokers, and 33.3% were diabetic. Reference investigations were catheter or cross-sectional angiography(n = 5), aortoiliac duplex(n = 2), and intra-arterial pressures(n = 1). The pooled negative predictive value was 84.7% (95% confidence interval [CI]: 59.3%-97.0%), meaning a triphasic waveform correctly excludes significant aortoiliac disease 84.7% of the time, and positive predictive value was 71.3% (95% CI: 36.1%-93.1%). Sensitivity was 0.86 (95% CI: 0.78-0.92), indicating 14% of patients with significant aortoiliac disease had triphasic waveforms, and specificity was 0.78 (95% CI: 0.61-0.89).

CONCLUSION

The best data available suggests Doppler waveform analysis lacks precision in identifying and excluding significant aortoiliac disease compared to heterogenous reference tests. A low threshold for cross-sectional imaging before antegrade endovascular intervention may be appropriate.

Editor's Choice - Delays to Revascularisation and Outcomes of Non-Elective Admissions for Chronic Limb Threatening Ischaemia: a UK Population Based Cohort Study

OBJECTIVE

Major amputation and death are significant outcomes after lower limb revascularisation for chronic limb threatening ischaemia (CLTI), but there is limited evidence on their association with the timing of revascularisation. The aim of this study was to examine the relationship between time from non-elective admission to revascularisation and one year outcomes for patients with CLTI.

METHODS

This was an observational, population based cohort study of patients aged ≥ 50 years with CLTI admitted non-electively for infrainguinal revascularisation procedures in English National Health Service hospitals from January 2017 to December 2019 recorded in the Hospital Episode Statistics database. Outcomes were death and ipsilateral major amputation rate at one year. Logistic regression models were fitted to explore the relationship between time to revascularisation and death, adjusted for patient and admission factors. For major amputation, multinomial logistic regression models were used to account for the competing risk of death.

RESULTS

A total of 10 183 patients (median age 75 years) were included in the analysis, of which 67.1% (n = 6 831) were male and 57.6% had diabetes. In patients with tissue loss, the unadjusted one year mortality rate was 30.0% (95% confidence interval [CI] 28.9 - 31.0%), and for every one day increase in time from admission to revascularisation, the adjusted odds of one year death increased by 3% (odds ratio 1.03, 95% CI 1.02 - 1.04). In the absence of tissue loss, the unadjusted one year mortality rate was 19.9% (95% CI 18.4 - 21.4%) and there was no evidence of an association with time to revascularisation. There was also no statistically significant association between the time to revascularisation and risk of ipsilateral major amputation at one year irrespective of tissue loss.

CONCLUSION

Patients undergoing infrainguinal revascularisation during non-elective admissions for CLTI have high one year major amputation and mortality rates. Longer time from admission to revascularisation was independently associated with a higher mortality rate in patients with tissue loss, but not in those without.

Evaluation of the Timing to Noncardiac Surgery following Cardiac Operations: A National Analysis

BACKGROUND

Despite advancements in peri-operative care and conflicting evidence regarding the need for preoperative coronary revascularization, the optimal timing of noncardiac surgery (NCS) following cardiac operations remains unclear.

OBJECTIVES

The purpose of this study was to evaluate the effect of time interval between cardiac surgery and NCS on peri-operative risk of major adverse events (MAEs).

METHODS

Adults undergoing elective CABG, valve repair or replacement, or combined procedures were identified in the 2016 to 2020 Nationwide Readmissions Database, with subsequent admission for NCS analyzed. The time interval in between NCS and index cardiac operations was modeled using restricted cubic splines, and clinical outcome differences were evaluated across various NCS risk and urgency categories.

RESULTS

Of 1,335,175 patients undergoing cardiac surgery, 20,253 (1.5%) required a subsequent NCS. On risk-adjusted examination of MAE rates as a function of time delay after cardiac surgery, an inflection point was noted at 100 days postoperatively. Based on this threshold, 47.9% of patients who had NCS within 100 days were considered early while others were grouped as late. Late NCS was associated with significantly lower odds of MAE (adjusted OR: 0.69; 95% CI: 0.62-0.76), and in-hospital mortality (adjusted OR: 0.66; 95% CI: 0.46-0.96), as compared to early NCS. This relationship persisted across all cardiac surgical subgroups and whether subsequent NCS was elective. Additionally, nonelective procedures classically categorized as low risk in the general population, exhibited comparable rates of MAE to high-risk procedures following early NCS.

CONCLUSIONS

When feasible, delaying NCS, particularly beyond 100 days, appears to be associated with a reduction in adverse events, suggesting a potential opportunity for optimization of patient outcomes.

Streamlined Clinical Management Pathways May Reduce Major Amputations in Patients with Chronic Limb Threatening Ischaemia: A Prospective Cohort Study with Historical Controls

OBJECTIVE

Patient characteristics and patterns of disease in chronic limb threatening ischaemia (CLTI) have markedly changed in recent years. Urgent specialist referral and timely revascularisation are recommended in international guidelines. UK guidelines now recommend revascularisation within five days of referral for inpatients and two weeks in outpatients. This study compared the contemporary one year major amputation incidence in patients with CLTI with a historical cohort at a single UK centre.

METHODS

This was a single centre, observational cohort study with historical controls. A prospective cohort was recruited between May 2019 and March 2022. A historical cohort presenting between 2013 and 2015 inclusive was retrospectively identified. Significant changes in management pathways, including establishing a rapid access limb salvage clinic, occurred between these periods, aiming to expedite time from referral to revascularisation. The one year primary outcome was major amputation, and the secondary outcome was death. Major amputation was analysed by Fine-Gray competing risks models (death as the competing risk), presented as subdistribution hazard ratios (SHRs). One year mortality was analysed by Cox regression, presented as hazard ratios. Analyses were adjusted for propensity score.

RESULTS

A total of 928 patients were included (432 prospective and 496 historical). Proportions of patients presenting with tissue loss (72.2% vs. 71.6%; p = .090) were similar in both cohorts. At one year, 48 patients (11.1%) in the prospective cohort and 124 patients (25.0%) in the historical cohort had undergone a major amputation (p < .001). Risk of major amputation was 57.0% lower in the prospective cohort compared with the historical cohort after adjustment for propensity score (SHR 0.43, 95% confidence interval 0.29 - 0.63; p < .001).

CONCLUSION

An encouraging reduction in major amputation incidence was observed after improvements to CLTI management pathways, but residual confounding is likely. The generalisability of these results is uncertain.

Institutional toe & flow programs: How and why the teams work

Diabetic foot ulcers with or without concomitant chronic limb-threatening ischemia put patients at exceedingly high risk of limb loss and death. The toe & flow model is a multidisciplinary team-based model captained by a podiatrist or orthopedic foot and ankle specialist and a vascular specialist, which streamlines treatment for patients with diabetic foot ulcer and chronic limb-threatening ischemia. This model creates a functional ecosystem around it by integrating other medical professionals and community partners. It provides a high standard of care first via community education and engagement. It eliminates barriers to access between it and the community by establishing clear referral pathways. This model uses the best available evidence to create treatment pathways governing the patient trajectory through different stage of disease. Once acute treatment is provided, it aims to consolidate success and disease remission through aggressive surveillance and collaboration with the community. An important aspect of this model is that it collects and reports its outcomes and serves as an educational hub within its region. It ultimately aims to develop national policies and allocate resources to continue to improve. This review sheds light on successes associated with institutional toe & flow programs.

Using Vascular Deserts as a Guide for Limb Preservation Outreach Programs Successfully Targets Underserved Populations

BACKGROUND

Vascular deserts, regions without vascular providers, previously described targets for limb salvage efforts. The Comprehensive Heart and Multidisciplinary Limb Preservation Outreach Networks (CHAMPIONS) programs targeted regions for outreach and evaluated the population using desert maps.

METHODS

At 2 events targeting underserved regions between 2022 and 2023, providers screened and educated participants on peripheral arterial and cardiovascular disease (PACD). Demographics and cardiovascular risk factors were collected. Using Arc geographic information system, vascular surgeons, and Vascular Quality Initiative (VQI) participating facilities were mapped with a 30-mile buffer. Participants were mapped with census data, and the healthy places index (HPI) was overlayed for population and social determinants of health data analysis in medical service study areas (MSSA), a geographical analysis unit. (Figure 1) Results were compared to prior statewide deserts.

RESULTS

Outreach program participants' mean age was 56 (range 6-88); 39% were male, and the majority were Hispanic (86%). 27% had no primary care provider (PCP). 30% had diabetes, 10% undiagnosed before the event, 38% had hypertension, 40% undiagnosed prior to the event, and 21% described intermittent claudication. 81% made <$30,000 annually, and 28% reported no health insurance. Similarities were observed when comparing program participant demographics to the population-level data from the targeted regions. Patients were more frequently Hispanic than other desert regions (68% vs. 36%, P < 0.001). Compared to other vascular desert regions, the target population was more disadvantaged in all HPI domains, including economic (18 vs. 38%, P < 0.001), education (21 vs. 39%, P < 0.001), and transportation (30 vs. 40%, P < 0.001). Worse education, financial, and transportation resources correspond to decreased care access due to poor literacy and travel burdens.

CONCLUSIONS

CHAMPIONS programs successfully targeted populations needing care based on vascular care desert maps, demonstrating that at-risk populations can be successfully identified and screened for cardiovascular disease.

Impact of the Affordable Care Act on Revascularization Versus Amputation in Patients Presenting With Chronic Limb-Threatening Ischemia in Maryland

INTRODUCTION

The Affordable Care Act (ACA) aimed to expand Medicaid, enhance health care quality and efficiency, and address health disparities. These goals have potentially influenced medical care, notably revascularization rates in patients presenting with chronic limb-threatening ischemia (CLTI). This study examines the effect of the ACA on revascularization vs amputation rates in patients presenting with CTLI in Maryland.

METHODS

This was a retrospective analysis of the Maryland State Inpatient Database comparing the rate of revascularization to rate of major amputation in patients presenting with CLTI over 2 periods: pre-ACA (2007-2009) and post-ACA (2018-2020). In this study, we included patients presenting with CLTI and underwent a major amputation or revascularization during that same admission. Using regression analysis, we estimated the odds of revascularization vs amputation pre- and post-ACA implementation, adjusting for pertinent variables.

RESULT

During the study period, 12,131 CLTI patients were treated. Post-ACA, revascularization rate increased from 43.9% to 77.4% among patients presenting with CLTI. This was associated with a concomitant decrease in the proportion of CLTI patients undergoing major amputation from 56.1% to 22.6%. In the multivariate analysis, there was a 4-fold odds of revascularization among patients with CLTI compared to amputation (OR = 4.73, 95% CI 4.34-5.16) post-ACA. This pattern was seen across all insurance groups.

CONCLUSION

The post-ACA period in Maryland was associated with an increased revascularization rate for patients presenting with CLTI with overall benefits across all insurance types.

Vein bypass first vs. best endovascular treatment first revascularisation strategy for chronic limb-threatening ischaemia due to infra-popliteal disease: the BASIL-2 RCT

Background

Chronic limb-threatening ischaemia with ischaemic pain and/or tissue loss.

Objective

To examine the clinical and cost-effectiveness of a vein bypass-first compared to a best endovascular treatment-first revascularisation strategy in preventing major amputation or death.

Design

Superiority, open, pragmatic, multicentre, phase III randomised trial.

Setting

Thirty-nine vascular surgery units in the United Kingdom, and one each in Sweden and Denmark.

Participants

Patients with chronic limb-threatening ischaemia due to atherosclerotic peripheral arterial disease who required an infra-popliteal revascularisation, with or without an additional more proximal infra-inguinal revascularisation procedure, to restore limb perfusion.

Interventions

A vein bypass-first or a best endovascular treatment-first infra-popliteal, with or without an additional more proximal infra-inguinal revascularisation strategy.

Main outcome measures

The primary outcome was amputation-free survival. Secondary outcomes included overall survival, major amputation, further revascularisation interventions, major adverse limb event, health-related quality of life and serious adverse events.

Methods

Participants were randomised to a vein bypass-first or a best endovascular treatment-first revascularisation strategy. The original sample size of 600 participants (247 events) was based on a hazard ratio of 0.66 with amputation-free survival rates of 0.72, 0.62, 0.53, 0.47 and 0.35 in years 1-5 in the best endovascular treatment-first group with 90% power and alpha at p = 0.05. The sample size was revised to an event-based approach as a result of increased follow-up time due to slower than anticipated recruitment rates. Participants were followed up for a minimum of 2 years. A cost-effectiveness analysis was employed to estimate differences in total hospital costs and amputation-free survival between the groups. Additionally, a cost-utility analysis was carried out and the total cost and quality-adjusted life-years, 2 and 3 years after randomisation were used.

Results

Between 22 July 2014 and 30 November 2020, 345 participants were randomised, 172 to vein bypass-first and 173 to best endovascular treatment-first. Non-amputation-free survival occurred in 108 (63%) of 172 patients in the vein bypass-first group and 92 (53%) of 173 patients in the best endovascular treatment-first group [adjusted hazard ratio 1.35 (95% confidence interval 1.02 to 1.80); p = 0.037]. Ninety-one (53%) of 172 patients in the vein bypass-first group and 77 (45%) of 173 patients in the best endovascular treatment-first group died [adjusted hazard ratio 1.37 (95% confidence interval 1.00 to 1.87)]. Over follow-up, the economic evaluation discounted results showed that best endovascular treatment-first was associated with £1690 less hospital costs compared to vein bypass-first. The cost utility analysis showed that compared to vein bypass-first, best endovascular treatment-first was associated with £224 and £2233 less discounted hospital costs and 0.016 and 0.085 discounted quality-adjusted life-year gain after 2 and 3 years from randomisation.

Limitations

Recruiting patients to the Bypass versus Angioplasty in Severe Ischaemia of the Leg Trial-2 trial was difficult and the target number of events was not achieved.

Conclusions

A best endovascular treatment-first revascularisation strategy was associated with better amputation-free survival, which was largely driven by fewer deaths. Overall, the economic evaluation results suggest that best endovascular treatment-first dominates vein bypass-first in the cost-effectiveness analysis and cost-utility analysis as it was less costly and more effective than a vein bypass-first strategy.

Future work

The Bypass versus Angioplasty in Severe Ischaemia of the Leg Trial-2 investigators have a data sharing agreement with the BEst Surgical Therapy in patients with Chronic Limb threatening Ischaemia investigators. One output of this collaboration will be an individual patient data meta-analysis.

Study registration

Current Controlled Trials ISRCTN27728689.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/35/45) and is published in full in Health Technology Assessment; Vol. 28, No. 65. See the NIHR Funding and Awards website for further award information.

Contemporary Outcomes of Infrainguinal Vein Bypass Surgery for Chronic Limb-Threatening Ischaemia: A Two-Centre Cross-Sectional Study

Background/Objectives: Chronic limb-threatening ischaemia (CLTI) is a significant life and limb-threatening condition. Two recent seminal trials, BEST-CLI and BASIL-2, have provided seemingly conflicting results concerning the optimal treatment modality for patients with CLTI. We sought to investigate the outcomes of patient undergoing infrainguinal bypass at two centres in Aotearoa New Zealand. Methods: A cross-sectional retrospective review of all patients who underwent infrainguinal bypass grafting for CLTI at Auckland City Hospital and Waikato Hospital between January 2020 and December 2021 was performed. The primary outcome was a composite of death, above-ankle amputation, and major limb reintervention. The secondary outcome was minor limb reintervention. Kaplan-Meier survival analysis was performed to determine time to the primary and secondary endpoints. Demographic factors were examined using the log-rank test to examine the effect on the outcome. Results: One hundred and nineteen patients who underwent infrainguinal bypass for CLTI in the study period were identified. Of these, 93 patients had a bypass with ipsilateral or contralateral GSV. The median follow-up time was 1.85 years. The most common indication for surgery was tissue loss (69%, n = 63), with the most common distal bypass target being the below-knee popliteal artery (45%, n = 41). The primary composite outcome occurred in 42.8% of the cohort (n = 39). Death was the most common component of the primary outcome (26%, n = 24). Male sex (HR 0.48, 95% CI 0.26-0.88, p = 0.018) and statin use (HR 0.49, 95% CI 0.24-0.98, p = 0.044) were independent predictors of protection from the composite outcome on multivariate analysis. Dialysis dependence (HR 3.32, 95% CI 1.23-8.99, p = 0.018) was an independent predictor for patients meeting the composite outcome. Conclusions: This study's results are consistent with the published outcomes of BEST-CLI. The patient cohorts examined, anatomical disease patterns, and conduit use may explain some of the differences observed between this study, BEST-CLI and BASIL-2. Further work is required to define the specific patient populations who will benefit most from an open surgical or endovascular first approach to the management of CLTI.

Economic impact of limb-salvage strategies in chronic limb-threatening ischaemia: modelling and budget impact study based on national registry data

BACKGROUND

Missed opportunities to reduce numbers of primary major lower-limb amputation and increase limb-salvage procedures when treating chronic limb-threatening ischaemia have previously been identified in the literature. However, the potential economic savings for healthcare providers when salvaging a chronic limb-threatening ischaemia-affected limb have not been well documented.

METHODS

A model using National Health Service healthcare usage and cost data for 1.6 million individuals and averaged numbers of primary surgical procedures for chronic limb-threatening ischaemia from England and Wales in 2019-2021 was created to perform a budget impact analysis. Two scenarios were tested: the averaged national rates of major lower-limb amputation (above the ankle joint), angioplasty, open bypass surgery or arterial endarterectomy in the National Vascular Registry (current scenario); and revascularization rates adjusted based on the lowest amputation rate reported by the National Vascular Registry at the time of the study (hypothetical scenario). The primary outcome was the net impact on costs to the National Health Service over 12 months after the index procedure.

RESULTS

In the current scenario, the proportions of different index procedures were 10% for lower-limb major amputation, 55% for angioplasty, 25% for open bypass surgery and 10% for arterial endarterectomy. In the hypothetical scenario, the procedure rates were 3% for major lower-limb amputation, 59% for angioplasty, 27% for open bypass surgery and 11% for arterial endarterectomy. For 16 025 index chronic limb-threatening ischaemia procedures, the total care cost in the current scenario was €243 924 927. In the hypothetical scenario, costs would be reduced for index procedures (-€10 013 814), community care (-€633 943) and major cardiovascular events (-€383 407), and increased for primary care (€59 827), outpatient appointments (€120 050) and subsequent chronic limb-threatening ischaemia-related surgery (€1 179 107). The net saving to the National Health Service would be €9 645 259.

CONCLUSION

A shift away from primary major lower-limb amputation towards revascularization could lead to substantial savings for the National Health Service without major cost increases later in the care pathway, indicating that care decisions taken in hospitals have wider benefits.

Patient experience of the process to diagnosis of chronic limb-threatening ischaemia: A qualitative study

INTRODUCTION

Delays exist at each stage of the chronic limb-threatening ischaemia (CLTI) care pathway, but there is little known about patient factors influencing delay to diagnosis of CLTI. This study explores the experiences and perceptions of patients recently diagnosed with CLTI.

METHODS

A qualitative interview study was conducted. Sixteen participants underwent semi-structured interviews. Reflexive thematic analysis was performed on the data, aiming to understand factors which can influence delay in the CLTI care pathway.

RESULTS

Five interrelated themes were developed: CLTI is a devastating condition; Reluctance to ask for help; When we are empowered we get better care; Luck plays a role in the process to diagnosis; and Vascular units can do better, comprising sub-themes of information transfer-consider communication and arterial versus non-arterial centres-proximity isn't everything.

CONCLUSIONS

The five themes generated from the interview data describe factors relevant to delay given meaning by participants who have lived experience of CLTI. Theme content should be noted by clinicians, commissioners and providers looking to improve care pathways for patients with CLTI. The importance of awareness for the public, patients and clinicians linked ideas in some themes and interventions to raise awareness should be considered.

Illness Trajectories After Revascularization in Patients With Peripheral Artery Disease: A Unified Approach to Understanding the Risk of Major Amputation and Death

BACKGROUND

The aim of this study was to investigate the illness trajectories of patients with peripheral artery disease (PAD) after revascularization and estimate the independent risks of major amputation and death (from any cause) and their interaction.

METHODS

Data from Hospital Episode Statistics Admitted Patient Care were used to identify patients (≥50 years of age) who underwent lower limb revascularization for PAD in England from April 2013 to March 2020. A Markov illness-death model was developed to describe patterns of survival after the initial lower limb revascularization, if and when patients experienced major amputation, and survival after amputation. The model was also used to investigate the association between patient characteristics and these illness trajectories. We also analyzed the relative contribution of deaths after amputation to overall mortality and how the risk of mortality after amputation was related to the time from the index revascularization to amputation.

RESULTS

The study analyzed 94 690 patients undergoing lower limb revascularization for PAD from 2013 to 2020. The majority were men (65.6%), and the median age was 72 years (interquartile range, 64-79). One-third (34.8%) of patients had nonelective revascularization, whereas others had elective procedures. For nonelective patients, the amputation rate was 15.2% (95% CI, 14.4-16.0) and 19.9% (19.0-20.8) at 1 and 5 years after revascularization, respectively. For elective patients, the corresponding amputation rate was 2.7% (95% CI, 2.4-3.1) and 5.3% (4.9-5.8). Overall, the risk of major amputation was higher among patients who were younger, had tissue loss, diabetes, greater frailty, nonelective revascularization, and more distal procedures. The mortality rate at 5 years after revascularization was 64.3% (95% CI, 63.2-65.5) for nonelective patients and 33.0% (32.0-34.1) for elective patients. After major amputation, patients were at an increased risk of mortality if they underwent major amputation within 6 months after the index revascularization.

CONCLUSIONS

The illness-death model provides an integrated framework to understand patient outcomes after lower limb revascularization for PAD. Although mortality increased with age, the study highlights patients <60 years of age were at increased risk of major amputation, particularly after nonelective revascularization.

Timing of Noncardiac Surgery Following Transcatheter Aortic Valve Replacement: A National Analysis

BACKGROUND

The optimal timing of noncardiac surgery (NCS) following transcatheter aortic valve replacement (TAVR) for aortic stenosis has not been elucidated by current national guidelines.

OBJECTIVES

The aim of this study was to evaluate the effect of the time interval between TAVR and NCS (Δt) on the perioperative risk of major adverse events (MAEs).

METHODS

All adult admissions for isolated TAVR for aortic stenosis were identified in the 2016 to 2020 Nationwide Readmissions Database. Patients who received NCS on subsequent admission were included for analysis and grouped by Δt as follows: ≤30, 31 to 60, 61 to 90, and >90 days. Multivariable regression models were constructed to examine the association of Δt with ensuing outcomes.

RESULTS

Of 3,098 patients (median age = 79 years, 41.6% female), 19.1% underwent NCS at ≤30 days, 22.9% at 31 to 60 days, 16.7% at 61 to 90 days, and 41.3% at >90 days. After adjustment, the odds of MAEs were similar for operations performed at ≤30 days (adjusted OR [AOR]: 1.05; 95% CI: 0.74-1.50), 31 to 60 days (AOR: 0.97; 95% CI: 0.71-1.31), and 61 to 90 days (AOR: 0.95; 95% CI: 0.67-1.34), with those at >90 days as reference. When examining the average marginal effect of the interval to surgery, risk-adjusted MAE rates were statistically similar across Δt groups for elective status and NCS risk category combinations.

CONCLUSIONS

NCS within 30, 31 to 60, or 61 to 90 days after TAVR was not associated with increased odds of MAEs compared with operations after 90 days irrespective of NCS risk category or elective status. Our findings suggest that the interval between NCS and TAVR may not be an accurate predictor of MAE risk in this population.

The Incidence and Outcomes of Major Limb Amputation in New Zealand from 2010 to 2021

Background: Major limb amputation (MLA) can be a common outcome due to severe peripheral artery disease (PAD) and diabetic foot disease (DFD), and it carries a significant mortality burden. In New Zealand (NZ), there is little documentation of the incidence rate and mortality after MLA. The aim was to report the national crude and standardised rates and the mortality post MLA. Methods: This retrospective observational study included all MLAs that occurred within NZ from 1/1/2010 to 31/12/2021 due to DFD and/or PAD. Two national databases (National Minimum Dataset and the Australasian Vascular Audit) were utilised. The crude rates were calculated as cases per 100,000 in the NZ population per year including all ages (using the 2013 and 2018 NZ census figures). The age-standardised rates used the World Health Organization standard population. Post-operative mortality was calculated from the date of first hospitalisation for MLA. Results: From 2010 to 2021, there were 5293 MLA procedures in 4242 patients. On average, there were 8.5 MLAs per week and 441.1 MLAs annually. The overall crude rate was 9.44 per 100,000, and the standardised rate was 6.12 per 100,000. Over the 12 years, the crude rate decreased by 22% (p < 0.001), and the standardised rate decreased by 20.4% (p < 0.001). After MLA, the 30-day and 1-year mortality was 9.5% and 29.6%, respectively. From 2010 to 2021, the relative reduction in 30-day mortality was 45.1% (p < 0.001), and the reduction in 1-year mortality was 24.5% (p < 0.001). Increasing age, female sex and end-stage renal failure were predictors of 30-day and 1-year mortality. Conclusions: A considerable number of MLAs occur in NZ, with substantial perioperative mortality; however, the national incidence rates and mortality have improved over the last 12 years. This data might serve as benchmark to further reduce MLAs and improve patient outcomes.

Understanding delays in chronic limb-threatening ischaemia care: Application of the theoretical domains framework to identify factors affecting primary care clinicians' referral behaviours

INTRODUCTION

Patients in the community with suspected Chronic limb-threatening ischaemia (CLTI) should be urgently referred to vascular services for investigation and management. The Theoretical Domains Framework (TDF) allows identification of influences on health professional behaviour in order to inform future interventions. Here, the TDF is used to explore primary care clinicians' behaviours with regards to recognition and referral of CLTI.

METHODS

Semi-structured interviews were conducted with 20 podiatrists, nurses and general practitioners in primary care. Directed content analysis was performed according to the framework method. Utterances were coded to TDF domains, and belief statements were defined by grouping similar utterances. Relevance of domains was confirmed according to belief frequency, presence of conflicting beliefs and the content of the beliefs indicating relevance.

RESULTS

Nine TDF domains were identified as relevant to primary care clinicians: Knowledge, Environmental context and resources, Memory, Decision and attention processes, Beliefs about capabilities, Skills, Emotions, Reinforcement and Behavioural regulation. Relationships across domains were identified, including how primary care clinician confidence and working in a highly pressurized environment can affect behaviour.

CONCLUSION

We have identified key barriers and enablers to timely recognition and referral behaviour. These beliefs identify targets for theory-driven behaviour change interventions to reduce delays in CLTI pathways.

Documentary analysis of national and international guidance for community clinicians referring patients with suspected chronic limb-threatening ischaemia

BACKGROUND

Delayed referral of patients with chronic limb-threatening ischaemia (CLTI) from the community to vascular services may increase risk of amputation due to delayed revascularisation. Lack of appropriate guidance for clinicians in the community may contribute to this problem. This documentary analysis investigated referral guidance available to primary care clinicians.

METHODS

National and international documents providing guidance on CLTI management were identified by searching sources including Medline, Embase, Guidelines International Network and College/Society websites. Data were extracted on referral recommendations, target audience and author groups. Recommendations were coded according to the Behaviour Change Technique Taxonomy. Clinical practice guideline quality and ease of implementation were assessed independently by two reviewers using the Appraisal of Guidelines Research and Evaluation (AGREE) II and Guideline Implementability Appraisal (GLIA) tools, respectively.

RESULTS

12 documents containing guidance on CLTI referrals were included. Five were clinical practice guidelines. Nine targeted clinicians in the community among their audience, yet only one included a primary care clinician in their author group. Recommendations on identification and referral of CLTI were often in non-specific language and frequently assumed specialist knowledge of vascular disease. Just 4 of the 93 behaviour change techniques were identified in the guidance documents. Three relevant domains of the AGREE II tool were scored for five clinical practice guidelines: stakeholder involvement (range 21.4%-52.4%, mean 42.9%), clarity of presentation (range 71.4%-92.9%, mean 82.9%) and applicability (25.0%-57.1%, mean 36.8%). The GLIA tool identified barriers to ease of implementation for all five clinical practice guidelines.

CONCLUSIONS

Most guidance for clinicians in the community on the management of CLTI has been written without their input and assumes knowledge of vascular disease, which may be lacking. Future guidance development should involve community clinicians, consider using additional behaviour change techniques, and improve the applicability and ease of implementation of recommendations.

An Endovascular- Versus a Surgery-First Revascularization Strategy for Chronic Limb-Threatening Ischemia: A Meta-Analysis of Randomized Controlled Trials

Timely revascularization is essential for limb salvage and to reduce mortality in patients with chronic limb-threatening ischemia (CLTI). In patients who are candidates for endovascular therapy and surgical bypass, the optimal revascularization strategy remains uncertain. Recently published randomized controlled trials (RCTs) have presented conflicting results. We conducted a trial-level meta-analysis to compare the outcomes between endovascular-first and surgery-first strategies for revascularization. PubMed, Web of Science, and the Cochrane Library were searched to identify RCTs comparing the outcomes of endovascular-first versus surgery-first strategies for revascularization in patients with CLTI. Data were pooled for major outcomes and their aggregate risk ratios (RRs) with 95% confidence intervals were calculated using a random-effects model. Kaplan-Meier curves for amputation-free survival and overall survival time were plotted using the pooled aggregated data from published curves, with their corresponding hazard ratios (HRs) and 95% confidence intervals reported for up to 5 years of follow-up. A total of 3 RCTs with 2,627 patients (1,312 endovascular-first and 1,315 surgery-first) were included in the meta-analysis. Of these, 1,864 patients (70.9%) were men and 347 (13.2%) were older than 80 years. Comparing the endovascular-first and surgery-first approaches, there was no significant difference in the overall (HR 0.92 [0.83 to 1.01], p = 0.09) or amputation-free survival (HR 0.98 [0.92 to 1.03], p = 0.42), reintervention (RR 1.24 [0.74 to 2.07], p = 0.41), major amputation, (RR 1.16 [0.87 to 1.54], p = 0.31), or therapeutic crossover (RR 0.92 [0.37 to 2.26], p = 0.85). In conclusion, data from available RCTs suggest that there is no difference in clinical outcomes between endovascular-first and surgery-first revascularization strategies for CLTI. A planned patient-level meta-analysis may provide further insight.

The symptom to assessment pathway for suspected chronic limb-threatening ischaemia (CLTI) affects quality of care: a process mapping exercise

BACKGROUND

Delays in the pathway from first symptom to treatment of chronic limb-threatening ischaemia (CLTI) are associated with worse mortality and limb loss outcomes. This study examined the processes used by vascular services to provide urgent care to patients with suspected CLTI referred from the community.

METHODS

Vascular surgery units from various regions in England were invited to participate in a process mapping exercise. Clinical and non-clinical staff at participating units were interviewed, and process maps were created that captured key staff and structures used to create processes for referral receipt, triage and assessment at the units.

RESULTS

Twelve vascular units participated, and process maps were created after interviews with 45 participants. The units offered multiple points of access for urgent referrals from general practitioners and other community clinicians. Triage processes were varied, with units using different mixes of staff (including medical staff, podiatrists and s) and this led to processes of varying speed. The organisation of clinics to provide slots for 'urgent' patients was also varied, with some adopting hot clinics, while others used dedicated slots in routine clinics. Service organisation could be further complicated by separate processes for patients with and without diabetes, and because of the organisation of services regionally into vascular networks that had arterial and non-arterial centres.

CONCLUSIONS

For referred patients with symptoms of CLTI, the points of access, triage and assessment processes used by vascular units are diverse. This reflects the local context and ingenuity of vascular units but can lead to complex processes. It is likely that benefits might be gained from simplification.

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

Objective

In 2022, the National Health Service Commissioning for Quality and Innovation (CQUIN) indicator for vascular surgery, with its pay-for-performance incentive for timely (5-day) revascularization of chronic limb-threatening ischemia (CLTI), was introduced. We sought to assess its effects in terms of (1) changes in the care pathway process measures relating to timing and patient outcomes; and (2) adherence to the Peripheral Arterial Disease Quality Improvement Framework (PAD-QIF) guidelines for patients admitted with CLTI.

Methods

A retrospective before-and-after cohort study was performed from January to June 2022 of nonelective admissions for CLTI who underwent revascularization (open, endovascular, or hybrid) at Cambridge University Hospitals National Health Service Foundation Trust, a regional vascular "hub." The diagnostic and treatment pathway timing-related process measures recommended in the PAD-QIF were compared between two 3-month cohorts-before vs after introduction of the CQUIN.

Results

For the two cohorts (before vs after CQUIN), 17 of 223 and 17 of 219 total admissions met the inclusion criteria, respectively. After introduction of financial incentives, the percentage of patients meeting the 5-day targets for revascularization increased from 41.2% to 58.8% (P = .049). Improvements were also realized in the attainment of PAD-QIF targets for a referral-to-admission time of ≤2 days (from 82.4% to 88.8%; P = .525) and admission-to-specialist-review time of ≤14 hours (from 58.8% to 76.5%; P = .139). An increase also occurred in the percentage of patients receiving imaging studies within 2 days of referral (from 58.8% to 70.6%; P = .324). The reasons for delay included operating list pressures and unsuitability for intervention (eg, active COVID-19 [coronavirus disease 2019] infection). No statistically significant changes to patient outcomes were observed between the two cohorts in terms of complications (pre-CQUIN, 23.5%; post-CQUIN, 41.2%; P = .086), length of stay (pre-QUIN, 12.0 ± 12.0 days; post-QUIN, 15.0 ± 21.0 days; P = .178), and in-hospital mortality (pre-QUIN, 0%; post-QUIN, 5.9%). Other PAD-QIF targets relating to delivery of care were poorly documented for both cohorts. These included documented staging of limb threat severity with the WIfI (wound, ischemia, foot infection) score (2.9% of patients; target >80%), documented shared decision-making (47.1%; target >80%), documented issuance of written information to patient (5.9%; target 100%), and geriatric assessment (6.3%; target >80%).

Conclusions

The pay-for-performance incentive CQUIN indicators appear to have raised the profile for the need for early revascularization to treat CLTI, engaging senior hospital management, and reducing the time to revascularization in our cohort. Further data collection is required to detect any resultant changes in patient outcomes. Documentation of guideline targets for delivery of care was often poor and should be improved.

Outcomes and use of healthcare resources after an intervention for chronic limb-threatening ischaemia

BACKGROUND

The fate of patients with chronic limb-threatening ischaemia undergoing revascularization or a primary amputation is unclear. The aim of this study was to assess the postoperative outcomes and post-procedural healthcare resource use/costs over 1 year after revascularization or a primary amputation for chronic limb-threatening ischaemia.

METHODS

The UK Kent Integrated Dataset, which links primary, community, and secondary care for 1.6 million people, was interrogated. All patients with a new diagnosis of chronic limb-threatening ischaemia undergoing revascularization or a major amputation between January 2016 and January 2019 (3 years) were identified. Postoperative events across all healthcare settings and post-procedure healthcare resource use were analysed over 1 year (until the end of 2019).

RESULTS

Overall, 4252 patients with a new diagnosis of chronic limb-threatening ischaemia were identified (65 per cent were male and the mean age was 73 years) between January 2016 and January 2019, of whom 579 (14 per cent) underwent an intervention (studied population); 296 (7 per cent) had an angioplasty, 75 (2 per cent) had bypass surgery, 141 (3 per cent) had a primary major lower limb amputation, 11 had a thrombo-embolectomy (0.3 per cent), and 56 had an endarterectomy (1.3 per cent). Readmissions (median of 2) were similar amongst different procedures within 1 year; bypass surgery was associated with more hospital appointments (median of 4 versus 2; P = 0.002). Patients undergoing a primary amputation had the highest number of cardiovascular events and 1-year mortality. In a linear regression model, index procedure type and Charlson co-morbidity index score were not predictors of appointments in primary/secondary care, community care visits, or readmissions after discharge. There were no statistically significant differences regarding post-procedural healthcare costs between procedures over 1 year.

CONCLUSION

Revascularization is not associated with more hospital, primary/community care appointments or increased post-procedural healthcare costs over 1 year when compared with primary amputation, in people with chronic limb-threatening ischaemia.

Impact of Vascular Service Centralization on the Carotid Endarterectomy Pathway: A Study at the Bedfordshire, Luton, and Milton Keynes Vascular Network

Introduction Carotid endarterectomy (CEA) is the gold standard intervention for patients experiencing transient ischemic attacks (TIAs) or embolic strokes with >50% internal carotid artery (ICA) stenosis supplying index hemispheric territory. The recommended period for CEA is 14 days post-index event; this period carries a heightened risk for second ischemic events. However, implementation of this stringent timeline often encounters delays stemming from multifaceted factors. The centralization of vascular services, designed to enhance patient care, introduces a paradigm shift. Centralization's efficacy in improving patient outcomes, particularly in the CEA pathway, is a subject of ongoing investigation. Our study aims to discern the impact of centralized services on the timeliness of CEA for symptomatic carotid artery stenosis, shedding light on this complex interplay of factors. Methods This retrospective study analyzed CEA data at the Bedfordshire, Luton, and Milton Keynes Vascular Network between January 2021 and June 2023. Eligible patients exhibited symptomatic carotid artery stenosis, with asymptomatic cases; those unfit for surgery or receiving best medical therapy only were excluded. Patients were categorized by their primary referral location: Hub, Spoke-1, or Spoke-2. Demographic and referral data were collected, and timelines from symptom onset to surgery were recorded. Continuous variables were expressed as means and standard deviations, and categorical variables as counts and percentages. Box plots illustrated the relationship between referral origin and surgery timing, and the Classification and Regression Tree (CART) assessed second events. Statistical significance was determined using Fisher's exact and chi-square tests, with p<0.05 indicating significance. Results A total of 148 patients underwent CEA after implementing exclusion criteria. 35.5% (n=53) of patients were referred from the Hub, while 45.6% (n=67) and 18.8% (n=28) were from Spoke-1 and Spoke-2, respectively. 40% (n=59) received CEA within the recommended timeframe, and 15.4% (n=23) experienced a second ischemic event pre-surgery. Time from TIA clinic review to referral was 5.5±8 days and 16.4±20 days from vascular referral to surgery. Patterns of delays were observed, with Spoke-2 exhibiting the most significant delays. Notably, amaurosis fugax and embolic stroke correlated with recurrent ischemic events, emphasizing the importance of timely care in CEA. Conclusion Our study underscores the significant benefits and challenges of the Hub and Spoke model in vascular surgery. The growing referral delays from Spoke sites are concerning, emphasizing the need for a multi-disciplinary team approach within Spoke sites to ensure efficient and standardized care delivery.

Hospital clinicians' perceptions and experiences of care pathways for chronic limb-threatening ischaemia: a qualitative study

BACKGROUND

Chronic limb-threatening ischaemia (CLTI) is a condition associated with significant risks of lower limb loss and mortality, which increase with delays in management. Guidance recommends urgent referral and assessment, but delays are evident at every stage of the CLTI patient pathway. This study uses qualitative methods to explore hospital clinicians' experiences and perceptions of the existing CLTI pathway.

METHODS

A qualitative interview study was conducted. Semi-structured interviews were undertaken with 13 clinicians involved in the assessment of patients referred to hospital with suspected CLTI, identified via purposive sampling from English vascular surgery units. Clinicians included podiatrists, vascular specialist nurses and doctors. Reflexive thematic analysis was performed on the data from a critical realist position.

RESULTS

The need for speed was the single overarching theme identified. Four linked underlying themes were also identified; 1. Vascular surgery as the poor relation (compared to cancer and other specialties), with a sub-theme of CLTI being a challenging diagnosis. 2. Some patients are more equal than others, with sub-themes of diabetes vs. non-diabetes, hub vs. spoke and frailty vs. non-frail. 3. Life in the National Health Service (NHS) is tough, with sub-themes of lack of resource and we're all under pressure. 4. Non-surgeons can help.

CONCLUSIONS

The underlying themes generated from the rich interview data describe barriers to timely referral, assessment and management of CLTI, as well as the utility of non-surgical roles such as podiatrists and vascular specialist nurses as a potential solution for delays. The overarching theme of the need for speed highlights the meaning given to adverse consequences of delays in management of CLTI by clinicians involved in its assessment. Future improvement projects aimed at the CLTI pathway should take these findings into account.

Peripheral Interventional Strategy Assessment (PISA) for Diabetic Foot Ulcer Revascularization: Preliminary Outcomes of a Multidisciplinary Pilot Study

BACKGROUND

Digital subtraction angiography (DSA) still represents the gold standard for anatomical arterial mapping and revascularization decision-making in patients with chronic limb-threatening ischemia (CLTI), although DUS (Doppler Ultrasound) remains a primary non-invasive examination tool. The Global Vascular Guidelines established the importance of preoperative arterial mapping to guarantee an adequate in-line flow to the foot. The aim of this study was to evaluate the accuracy of DUS in guiding therapeutic vascular treatments on the basis of Global Vascular Guidelines without the need of a second-level examination.

METHODS

Between January 2022 and June 2022, all consecutive patients with CLTI to be revascularized underwent clinical examination and DUS without further diagnostic examinations. Primary outcomes assessed were technical success, and 30-day mortality. Secondary outcomes were 1-year amputation free survival, and time between evaluation and revascularization.

RESULTS

Sixty-eight patients with a mean age of 73.6 ± 8.5 years underwent lower limb revascularization. Technical success was 100%, and the 30-day mortality rate was 2.9%. Mean time between evaluation and revascularization was 29 ± 17 days. One-year amputation free survival was 97.1%.

CONCLUSIONS

DUS without further diagnostic examinations can accurately assess the status of the vascular tree and foot runoff, providing enough information about target vessels to guide revascularization strategies.