Cardiovascular and all-cause mortality in patients with intermittent claudication and critical limb ischaemia

The real-world data of lipid-lowering treatment in patients with peripheral artery disease and its association with severity of disease

BACKGROUND

The risk of coronary artery disease in peripheral arterial disease (PAD) is high, life prognosis is poor, and lipid-lowering treatment with statins has been reported to improve prognosis. In clinical practice, however, hypolipidemia is more common in patients with severe PAD and statin prescription rates appear to be low, but specific data are scarce in Japan. Therefore, we conducted this cross-sectional study in collaboration with other centers of vascular surgery to determine the rate of statin prescriptions for PAD patients in real-world practice, the rate of achievement of low-density lipoprotein (LDL) cholesterol control targets, and whether statin non-use is a determinant factor of critical limb ischemia (CLI).

METHODS

A total of 246 PAD patients (97 with CLI) from 5 sites were included in this study. Medical history and blood test data were obtained from medical records and interviews with patients, and were compared between CLI and non-CLI patients.

RESULTS

Statin prescription rate was only 34 %. The overall LDL cholesterol control target rate was 46 % of CLI cases and 51 % of non-CLI cases, according to the lipid management criteria of the Japanese Society for Atherosclerosis 2022 guidelines. Patients in the CLI group had a lower mean body mass index and lower LDL cholesterol levels than those in the non-CLI group, suggesting that these factors were responsible for the lower statin prescription rate. However, multivariate analysis revealed that statin non-use was one of the determinants of CLI.

CONCLUSIONS

Statin prescription rates for PAD patients were low in real-world practice settings in the field of vascular surgery. Since statin non-use is a determinant of CLI, there is a need to educate physicians engaged in treatment regarding lipid-lowering treatment with statins.

Association of Pedal Acceleration Time With Healing and Amputation Free Survival in Patients With Ulceration and Gangrene

OBJECTIVE

Pedal acceleration time (PAT) is a novel non-invasive perfusion measurement that may be useful in the management of patients with ulceration and gangrene. The objective of this study was to report the association between PAT and wound healing, amputation free survival (AFS), and mortality at one year.

METHODS

This prospective observational study reviewed all patients who underwent PAT after presentation with ulceration or gangrene from 1 January 2020 to 30 June 2022. PAT was defined as the time (in milliseconds) from the onset of systole to the peak of systole in the mid artery. The final PAT of a limb was used to assess outcomes (presenting PAT if no revascularisation, or post-revascularisation PAT). Wound healing, major limb amputation, and death at one year were collected. Healing was assessed with Fine-Gray competing risks model, AFS via logistic regression, and survival using Cox proportional hazards model.

RESULTS

Overall, 265 patients (307 limbs) were included. The median patient age was 71 years and 74.0% (196/265) had diabetes mellitus. Patient demographics were similar among the final PAT category cohorts. Compared with a final PAT category 1, analysis of one year outcomes showed that the final PAT categories 2 - 4 had lower wound healing (category 2, hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.43 - 0.9, p = .012; category 3, HR 0.21, 95% CI 0.08 - 0.58, p = .002; category 4, HR 0.12, 95% CI 0.04 - 0.34, p < .001), lower AFS (category 2, odds ratio [OR] 2.86, 95% CI 1.64 - 5.0, p < .001; category 3, OR 5.1, 95% CI 1.71 - 15.22, p = .003; category 4, OR 12.59, 95% CI 4.34 - 36.56, p < .001), and lower survival (category 2, HR 1.89, 95% CI 1.17 - 3.03, p =.009; category 3, HR 2.37, 95% CI 1.05 - 5.36, p = .039; category 4, HR 4.52, 95% CI 2.48 - 8.21, p < .001).

CONCLUSION

The final PAT measurement is associated with wound healing, AFS, and death at one year. PAT may be a valuable tool to assess perfusion of the foot.

Sex Differences in Mortality Risk after the First Hospitalisation with Lower Extremity Peripheral Arterial Disease

OBJECTIVE

Lower extremity peripheral arterial disease (PAD) is a severe condition that increases the risk of major adverse cardiovascular events, major adverse limb events, and all cause mortality. This study aimed to investigate the mortality risk among females and males hospitalised for the first time with lower extremity PAD.

METHODS

Three cohorts of patients who were admitted for the first time with lower extremity PAD in 2007 - 2010, 2011 - 2014, and 2015 - 2018 were constructed. For the 2007 - 2010 and 2011 - 2014 cohorts, the 28 day, one year, and five year mortality rates were calculated, assessing survival time from date of hospital admission until date of death, end of study period, or censoring. For the 2015 - 2018 cohort, only 28 day and one year mortality were investigated due to lack of follow up data. Mortality rates of these cohorts were compared with the general population using standardised mortality rates (SMRs), and the risk of death between sexes was evaluated using Cox proportional hazards models. Cox models were adjusted for age, cardiovascular disease, and diabetes mellitus to account for potential confounding factors.

RESULTS

In total, 7 950, 9 670, and 13 522 patients were included in the 2007 - 2010, 2011 - 2014, and 2015 - 2018 cohorts, respectively. Over 60% of individuals in each cohort were males. Mortality rates at 28 day and one year remained stable across all cohorts, while the five year mortality rate increased for both males and females in the 2011 - 2014 cohort. The SMRs both of females and males with PAD were significantly higher than in the general population. Multivariable regression analyses found no significant differences in mortality risk between sexes at 28 day and one year. However, the five year mortality risk was lower in females, with a hazard ratio of 0.89 (95% confidence interval [CI] 0.83 - 0.97) in the 2007 - 2010 cohort and 0.88 (95% CI 0.82 - 0.94) in the 2011 - 2014 cohort.

CONCLUSION

The five year mortality risk has increased, and females face a lower mortality risk than males. Lower extremity PAD still carries unfavourable long term consequences compared with the general population.

Toward Uniform Case Identification Criteria in Observational Studies on Peripheral Arterial Disease: A Scoping Review

BACKGROUND

The diagnosis of peripheral arterial disease (PAD) is commonly applied for symptoms related to atherosclerotic obstructions in the lower extremity, though its clinical manifestations range from an abnormal ankle-brachial index to critical limb ischemia. Subsequently, management and prognosis of PAD vary widely with the disease stage. A critical aspect is how this variation is addressed in administrative database-based studies that rely on diagnosis codes for case identification. The objective of this scoping review is to inventory the identification strategies used in studies on PAD that rely on administrative databases, to map the pros and cons of the International Classification of Diseases (ICD) codes applied, and to propose a first outline for a consensus framework for case identification in administrative databases.

METHODS

Registry-based reports published between 2010 and 2021 were identified through a systematic PubMed search. Studies were subcategorized on the basis of the expressed study focus: claudication, critical limb ischemia, or general peripheral arterial disease, and the ICD code(s) applied for case identification mapped.

RESULTS

Ninety studies were identified, of which 36 (40%) did not specify the grade of PAD studied. Forty-nine (54%) articles specified PAD grade studied. Five (6%) articles specified different PAD subgroups in methods and baseline demographics, but not in further analyses. Mapping of the ICD codes applied for case identification for studies that specified the PAD grade studied indicated a remarkable heterogeneity, overlap, and inconsistency.

CONCLUSIONS

A large proportion of registry-based studies on PAD fail to define the study focus. In addition, inconsistent strategies are used for PAD case identification in studies that report a focus. These findings challenge study validity and interfere with inter-study comparison. This scoping review provides a first initiative for a consensus framework for standardized case selection in administrative studies on PAD. It is anticipated that more uniform coding will improve study validity and facilitate inter-study comparisons.

Effect of supervised exercise training on cardiovascular function in patients with intermittent claudication: a systematic review and meta-analysis of randomized controlled trials

This study aimed to determine the effect of supervised exercise training (SET) on cardiovascular function in patients with intermittent claudication (IC). A systematic search in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases was conducted. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), rate pressure product (RPP), cardiac output (CO), peak oxygen consumption (VO2peak), and heart rate variability (HRV). Secondary outcomes were maximum walking distance (MWD) and pain-free walking distance (PFWD). Outcomes were reported as weighted mean difference (WMD) between the SET group and the control group and synthesized by using the random-effects model. Seventeen RCTs with a total of 936 patients were included in this review. SET resulted in significant improvements of SBP (WMD =  - 7.40, 95% CI - 10.69 ~  - 4.11, p < 0.001, I2 = 15.2%), DBP (WMD =  - 1.92, 95% CI - 3.82 ~  - 0.02, p = 0.048, I2 = 0.0%), HR (WMD =  - 3.38, 95% CI - 6.30 ~  - 0.46, p = 0.023, I2 = 0.0%), RPP (WMD =  - 1072.82, 95% CI - 1977.05 ~  - 168.59, p = 0.020, I2 = 42.7%), and VO2peak with plantar flexion ergometer exercise (WMD = 5.57, 95% CI 1.66 ~ 9.49, p = 0.005, I2 = 62.4%), whereas CO and HRV remained statistically unaltered. SET also improved MWD (WMD = 139.04, 95% CI 48.64 ~ 229.44, p = 0.003, I2 = 79.3%) and PFWD (WMD = 40.02, 95% CI 23.85 ~ 56.18, p < 0.001, I2 = 0.0%). In conclusion, SET is effective in improving cardiovascular function in patients with IC, which was confirmed on outcomes of cardiovascular function associated with exercise ability. The findings hold out that the standard therapy of SET can improve not only walking distance but also cardiovascular function in patients with IC.

High Mortality in Patients With an Ischemic Foot Ulcer Following Revascularization

Critical limb ischemia (CLI) is the advanced stage of peripheral arterial disease, which impairs blood flow to the extremities due to occlusion of arteries, in which patients suffer from ischemic pain at rest and gangrene or ulcers. It is frequently accompanied by major adverse cardiac events, resulting in exceedingly high mortality from a cardiac or cerebrovascular event in this population. Although there have been considerable amounts of novel and costly revascularization and wound dressing technology, mortality is still high. Therefore, the risk factors for such high mortality need to be addressed. This review aimed to summarize the potential risk factors for mortality in patients with CLI of the lower extremities. There are several such risk factors, including modifiable and nonmodifiable risk factors. This review further discusses some highlighted major modified risk factors, including renal failure, cardiovascular, and diabetes. The strategy of regular surveillance and modification of such risk factors in any patients with CLI should be developed.

Amputation Rates and Associated Social Determinants of Health in the Most Populous US Counties

Importance

Social Determinants of Health (SDOH) have been found to be associated with health outcome disparities in patients with peripheral artery disease (PAD). However, the association of specific components of SDOH and amputation has not been well described.

Objective

To evaluate whether individual components of SDOH and race are associated with amputation rates in the most populous counties of the US.

Design, Setting, and Participants

In this population-based cross-sectional study of the 100 most populous US counties, hospital discharge rates for lower extremity amputation in 2017 were assessed using the Healthcare Cost and Utilization Project State Inpatient Database. Those data were matched with publicly available demographic, hospital, and SDOH data. Data were analyzed July 3, 2022, to March 5, 2023.

Main outcome and Measures

Amputation rates were assessed across all counties. Counties were divided into quartiles based on amputation rates, and baseline characteristics were described. Unadjusted linear regression and multivariable regression analyses were performed to assess associations between county-level amputation and SDOH and demographic factors.

Results

Amputation discharge data were available for 76 of the 100 most populous counties in the United States. Within these counties, 15.3% were African American, 8.6% were Asian, 24.0% were Hispanic, and 49.6% were non-Hispanic White; 13.4% of patients were 65 years or older. Amputation rates varied widely, from 5.5 per 100 000 in quartile 1 to 14.5 per 100 000 in quartile 4. Residents of quartile 4 (vs 1) counties were more likely to be African American (27.0% vs 7.9%, P < .001), have diabetes (10.6% vs 7.9%, P < .001), smoke (16.5% vs 12.5%, P < .001), be unemployed (5.8% vs 4.6%, P = .01), be in poverty (15.8% vs 10.0%, P < .001), be in a single-parent household (41.9% vs 28.6%, P < .001), experience food insecurity (16.6% vs 12.9%, P = .04), or be physically inactive (23.1% vs 17.1%, P < .001). In unadjusted linear regression, higher amputation rates were associated with the prevalence of several health problems, including mental distress (β, 5.25 [95% CI, 3.66-6.85]; P < .001), diabetes (β, 1.73 [95% CI, 1.33-2.15], P < .001), and physical distress (β, 1.23 [95% CI, 0.86-1.61]; P < .001) and SDOHs, including unemployment (β, 1.16 [95% CI, 0.59-1.73]; P = .03), physical inactivity (β, 0.74 [95% CI, 0.57-0.90]; P < .001), smoking, (β, 0.69 [95% CI, 0.46-0.92]; P = .002), higher homicide rate (β, 0.61 [95% CI, 0.45-0.77]; P < .001), food insecurity (β, 0.51 [95% CI, 0.30-0.72]; P = .04), and poverty (β, 0.46 [95% CI, 0.32-0.60]; P < .001). Multivariable regression analysis found that county-level rates of physical distress (β, 0.84 [95% CI, 0.16-1.53]; P = .03), Black and White racial segregation (β, 0.12 [95% CI, 0.06-0.17]; P < .001), and population percentage of African American race (β, 0.06 [95% CI, 0.00-0.12]; P = .03) were associated with amputation rate.

Conclusions and Relevance

Social determinants of health provide a framework by which the associations of environmental factors with amputation rates can be quantified and potentially used to guide interventions at the local level.

A scoping review of female sex-related outcomes after endovascular intervention for lifestyle-limiting claudication and chronic limb-threatening ischemia

Peripheral arterial disease (PAD) is on the rise, with a growing prevalence in an aging population and increasing rates of diabetes. Chronic limb-threatening ischemia poses a significant risk of limb loss. PAD is common in females, particularly after menopause, with a 35% prevalence rate in females older than 65 years. Studies have suggested that females have inferior outcomes compared with men after endovascular revascularization for PAD. With the rising utilization of endovascular interventions for the treatment of PAD, we sought to perform a review of sex-based outcomes of peripheral endovascular interventions for the treatment of symptomatic PAD. A scoping literature review was conducted to evaluate outcomes in females patients undergoing endovascular peripheral interventions for PAD. Eligibility criteria included studies focusing on adult females with lifestyle-limiting claudication or chronic limb-threatening ischemia who underwent endovascular intervention. Various endovascular procedures were considered and outcomes of interest included mortality, amputations, reinterventions, bleeding complications, and major adverse cardiac events. A systematic search was conducted in PubMed, Embase, Web of Science, and Cochrane Library databases. Sixteen studies were included in the review. Females patients undergoing endovascular interventions were associated with bleeding complications, higher rates of reintervention, and a risk of nonfatal strokes. However, females sex was not linked to higher rates of amputation or conclusively higher mortality rates post intervention. The comprehensive scoping review reveals important sex-related disparities in outcomes after endovascular procedures for symptomatic PAD. Females patients have been reported to experience worse outcomes in terms of reinterventions and bleeding complications. These findings emphasize the need for future trials focusing specifically on females patients to develop sex-inclusive treatment recommendations for advanced PAD.

Five Year Survival in Medicare Patients Undergoing Interventions for Peripheral Arterial Disease: a Retrospective Cohort Analysis of Linked Registry Claims Data

OBJECTIVE

To justify the up front risks of offering elective interventions for intermittent claudication (IC), patients should have reasonable life expectancy to derive durable clinical benefits. Open surgery for chronic limb threatening ischaemia (CLTI) is maximally beneficial in patients surviving ≥ 2 years. The aim was to assess long term survival after IC and CLTI interventions.

METHODS

In a retrospective cohort analysis, the Vascular Quality Initiative (VQI) registry from 1 January 2010 to 31 May 2021 was queried for peripheral vascular intervention (PVI), infra-inguinal bypasses (IIB), and supra-inguinal bypasses (SIB) for IC and CLTI across 286 US centres. VQI linkage to Medicare insurance claims provided five year survival data. Multivariable analysis identified factors associated with five year mortality.

RESULTS

There were 31 457 PVIs (44.7% IC, 55.3% CLTI), 7 978 IIBs (26.9% IC, 73.1% CLTI), and 2 149 SIBs (50.1% IC, 49.9% CLTI) recorded in the VQI. Among the PVI, IIB, and SIB cohorts, average ages were 75, 73, and 72 years, respectively. Respective five year mortality after PVI for IC and CLTI was 37.2% and 71.1%; after IIB for IC and CLTI it was 37.8% and 60%; and after SIB for IC and CLTI it was 33.8% and 53.8%. On multivariable analysis, across all procedures, end stage renal disease, CLTI, congestive heart failure, anaemia, chronic obstructive pulmonary disease, and prior amputation were independently associated with increased mortality. Pre-admission home living and pre-operative aspirin use were independently associated with decreased mortality.

CONCLUSION

Long term survival in Medicare patients undergoing interventions in VQI centres for peripheral arterial disease is poor. Two thirds of CLTI patients and over one third of IC patients were not alive at five years. Intervening for IC in patients with high mortality risk should be avoided. For CLTI patients identified with decreased survival likelihood, intervention durability may be less important than invasiveness. Pre-operative medical optimisation should always be undertaken.

Limb Salvage and Survival in Chronic Limb-Threatening Ischemia: The Need for a Fast-Track Team-Based Approach

Chronic limb-threatening ischemia (CLTI) represents the end-stage form of peripheral arterial disease (PAD) and is associated with a very poor prognosis and high risk of limb loss and mortality. It can be considered very similar to a terminal cancer disease, reflecting a large impact on quality of life and healthcare costs. The aim of this study is to offer an overview of the relationship between CLTI, limb salvage, and mortality, with a focus on the need of a fast-track team-based management that is a driver to achieve better survival results. This review can be useful to improve management of this growing impact disease, and to promote the standardisation of care and communication between specialist and non-specialist healthcare professionals.

The Dutch chronic lower limb-threatening ischemia registry (THRILLER): A study protocol for popliteal and infrapopliteal endovascular interventions

INTRODUCTION

Chronic limb-threatening ischemia (CLTI) is the end stage of peripheral arterial disease (PAD) and is associated with high amputation rates, mortality and disease-related health care costs. In infrapopliteal arterial disease (IPAD), endovascular revascularization should be considered for the majority of anatomical and clinical subgroups of CLTI. However, a gap of high-quality evidence exists in this field. The aim of the Dutch Chronic Lower Limb-Threatening Ischemia Registry (THRILLER) is to collect real world data on popliteal and infrapopliteal endovascular interventions.

METHODS

THRILLER is a clinician-driven, prospective, multicenter, observational registry including all consecutive patients that undergo a popliteal or infrapopliteal endovascular intervention in seven Dutch hospitals. We estimate that THRILLER will include 400-500 interventions annually. Standardized follow-up visits with wound monitoring, toe pressure measurement and duplex ultrasonography will be scheduled at 6-8 weeks and 12 months after the intervention. The independent primary endpoints are primary patency, limb salvage and amputation free survival. Patients must give informed consent before participation and will be included according to predefined reporting standards. A data log of patients who meet the inclusion criteria but are not included in the registry will be maintained. We intend to conduct the first interim analysis two years after the start of inclusion. The results will be published in a scientific journal.

DISCUSSION

Despite innovations in medical therapy and revascularization techniques, patients with CLTI undergoing endovascular revascularization still have a moderate prognosis. Previous prospective cohort studies were hampered by small sample sizes or heterogeneous reporting. Randomized controlled trials (RCTs) have high costs, potential conflicts of interest and give a limited reflection of daily practice. THRILLER aims to provide the largest prospective well phenotyped up-to-date dataset on treatment outcomes in CLTI patients to answer multiple underexplored research questions regarding diagnostics, medication, patient selection, treatment strategies and post intervention follow-up.

To patch, or not to patch a common femoral artery, that is the question

OBJECTIVES

There is no strong evidence to support or reject the use of patch angioplasty (PA) after femoral endarterectomy (FE). The current study aimed to assess early postoperative complications and compare primary patency (PP) rates after FE in patients treated with PA versus direct closure (DC).

METHODS

This is a retrospective study of patients admitted during 06/2002-07/2017 with signs and symptoms of chronic lower limb ischemia (Rutherford categories 2-6). Patients with angiographically confirmed stenoses or occlusions of the common femoral arteries (CFAs) and managed with FE with or without PA were included in the study. Early postoperative wound complications were assessed. The PP analysis was based on imaging-confirmed data. The impact of PA on the patency was evaluated in a confounder-adjusted Cox regression model. PP rates were compared with log-rank between the PA and DC groups using Kaplan-Meier survival analysis in the propensity score-matched (PSM) cohorts.

RESULTS

A total of 295 primary FEs were identified. The patients' median age was 75 years. A total of 210 patients were managed with PA and 85 with DC. Altogether, 38 (12.9%) local wound complications were registered, 15 (5.1%) of which required re-interventions. There were 9 (3.2%) cases of deep wound infection, 20 (7.0%) seromas, and 11 (3.9%) cases of major bleeding, with no significant difference between the PA and DC groups. All of the infected patches were made of synthetic material, and 83% of them were removed. The PP analysis was performed on 50 PSM patient pairs with a median age of 74 years. The median imaging-confirmed follow-up lengths were 77 months (IQR = 47 months) for the PA patients and 27 months (IQR = 64 months) for the DC patients. The preoperative median diameter of the CFA was 8.8 mm (IQR = 3.4). The 5 year primary patency rates of CFAs with a minimum diameter of 5.5 mm managed with PA or DC exceeded 91%, p > 0.05. Female sex was associated with the loss of PP, odds ratio 4.17, p = 0.046.

CONCLUSIONS

Wound complications after FE with or without patching are not uncommon and often lead to reoperations. The PP rates of CFAs with a minimum diameter of 5.5 mm and accomplished with or without patching are comparable. Female sex is associated with the loss of patency.

Pedal arterial calcification score is associated with hemodynamic change and major amputation after infrainguinal revascularization for chronic limb-threatening ischemia

OBJECTIVE

Pedal medial arterial calcification (pMAC) is associated with major amputation in patients with CLTI. We hypothesize this association is related to unresolved distal ischemia. We investigated relationships across pMAC score, hemodynamic change, and major amputation following infrainguinal revascularization for CLTI.

METHODS

This is a single-institution retrospective study of 306 patients who underwent technically successful infrainguinal revascularization for CLTI (2011-2020) and had foot x-rays for blinded pMAC scoring (0-5). 136 (44%) had toe pressure measurements performed within 90 days before and 60 days after revascularization. Ischemia grade (0-3) was assigned using the SVS WIfI system.

RESULTS

Revascularization approach was open bypass in 118 (38%) and endovascular in 188 (62%) patients. pMAC scores were trichotomized [0-1 (125; 41%), 2-4 (116; 38%), 5 (65; 21%)]. Post-revascularization WIfI ischemia grade was improved in 78/136 (57%) and unchanged/worsened in 58/136 (43%). Lower pMAC score was associated with hemodynamic improvement (p=0.004). Failure to improve the ischemia grade was associated with major amputation (p=0.0002) In the endovascular subgroup, WIfI ischemia grade was improved in 43/90 (48%) with available measurements, and 37/188 (20%) underwent major amputation. In a multivariate logistic model, pMAC 5 was the only factor independently associated with unimproved ischemia grade after endovascular treatment [OR 4.0 (1.1-16.6), p=0.04]. In a Cox proportional hazards model, factors independently associated with major amputation after endoluminal revascularization were WIfI stage 4 [HR 2.7 (1.3-5.7), p=0.007] and pMAC score [pMAC 2-4: HR 10.6 (1.4-80.7), p=0.02; pMAC 5: HR 15.5 (2.0-119), p=0.008]. In the bypass subgroup, WIfI ischemia grade was improved in 35/46 (76%) with available measurements but was not associated with pMAC score (p=0.88) or any other baseline patient or limb characteristics. 19/118 (16%) underwent major amputation. In a Cox proportional hazards model including bypass conduit, WIfI stage, and pMAC score; the only factor independently associated with major amputation after bypass was use of non-autologous conduit [HR 5.6 (1.8-17.6), p=0.003].

CONCLUSION

The pMAC score is independently associated with persistent distal ischemia and major amputation after technically successful revascularization for CLTI. These data suggest that pMAC may be a marker for hemodynamic response to revascularization and risk of limb loss, and it may have a stronger influence on the outcome of endoluminal interventions.

Aortic calcification index predicts mortality and cardiovascular events in operatively treated patients with peripheral artery disease A prospective PUREASO cohort follow-up study

OBJECTIVE

Present study evaluates the association of aortic calcification to mortality and major adverse cardiovascular and leg events (MACE and MALE) in patients with peripheral artery disease (PAD). The risk for mortality and MACE and MALE events is considered in clinical decision making.

METHODS

This cohort found in 2012 - 2013 consists of 226 symptomatic PAD patients referred to Turku University Hospital for invasive treatment. Follow-up data about mortality and survival without MACEs and MALEs was collected up to 5 years from inclusion date and aortic calcification index (ACI) was measured from patients with available imaging studies (164 of 226). ACIs association with events and mortality was evaluated in Cox regression, Kaplan-Meier and Classification and regression tree analysis.

RESULTS

All-cause mortality at 1, 3 and 5 years was 13.7%, (31), 26.1% (59) and 46.9% (106), respectively. In multivariable Cox regression analysis ACI and ACI>43 were independent risk factors for all-cause mortality (HR 1.13 per 10 units 95%CI, 1.00-1.22 and HR 1.83, 95%CI, 1.01-3.32, respectively) and for MACE (HR 1.10 per 10 units, 95%CI, 1.00-1.22 and HR 3.14, 95%CI, 1.67-5.91, respectively), but not for MALES. Classification and regression tree analysis showed that ACI 43 best divides cohort in relation to mortality. Kaplan-Meier analyses showed that ACI>43 is associated with greater mortality and occurrence of MACEs compared to those who have ACI≤43 (log-rank p-value 0.005 and 0.0012, respectively).

CONCLUSION

Risk for mortality and MACEs is associated with high ACI. ACI can expose PAD patients' risk for further cardiovascular events and mortality.

The Incidence of Chronic Limb-Threatening Ischemia in the Midland Region of New Zealand over a 12-Year Period

The epidemiology of severe PAD, as characterized by short-distance intermittent claudication (IC) and chronic limb-threatening ischemia (CLTI), remains undefined in New Zealand (NZ). This was a retrospective observational cohort study of the Midland region in NZ, including all lower limb PAD-related surgical and percutaneous interventions between the 1st of January 2010 and the 31st of December 2021. Overall, 2541 patients were included. The mean annual incidence of short-distance IC was 15.8 per 100,000, and of CLTI was 36.2 per 100,000 population. The annual incidence of both conditions was greater in men. Women presented 3 years older with PAD (p < 0.001). Patients with short-distance IC had lower ipsilateral major limb amputation at 30 days compared to CLTI (IC 2, 0.3% vs. CLTI 298, 16.7%, p < 0.001). The 30-day mortality was greater in elderly patients (<65 years 2.7% vs. ≥65 years 4.4%, p = 0.049), but did not differ depending on sex (females 36, 3.7% vs. males 64, 4.1%, p = 0.787). Elderly age was associated with a worse survival for both short-distance IC and CLTI. There was a worse survival for females with CLTI. In conclusion, PAD imposes a significant burden in NZ, and further research is required in order to reduce this disparity.

High lipoprotein(a) is associated with major adverse limb events after femoral artery endarterectomy

BACKGROUNDS AND AIMS

Elevated lipoprotein(a) (Lp[a]) has been identified as a causal risk factor for cardiovascular disease including peripheral arterial disease (PAD). Although Lp(a) is associated with the diagnosis of PAD, it remains elusive whether there is an association of Lp(a) with cardiovascular and limb events in patients with severe PAD.

METHODS

Preoperative plasma Lp(a) levels were measured in 384 consecutive patients that underwent iliofemoral endarterectomy and were included in the Athero-Express biobank. Our primary objective was to assess the association of Lp(a) levels with Major Adverse Limb Events (MALE). Our secondary objective was to relate Lp(a) levels to Major Adverse Cardiovascular Events (MACE) and femoral plaque composition that was acquired from baseline surgery.

RESULTS

During a median follow-up time of 5.6 years, a total of 225 MALE were recorded in 132 patients. Multivariable analysis, including history of peripheral intervention, age, diabetes mellitus, end stage renal disease and PAD disease stages, showed that Lp(a) was independently associated with first (HR of 1.36 (95% CI 1.02-1.82) p = .036) and recurrent MALE (HR 1.36 (95% CI 1.10-1.67) p = .004). A total of 99 MACE were recorded but Lp(a) levels were not associated with MACE.sLp(a) levels were significantly associated with a higher presence of smooth muscle cells in the femoral plaque, although this was not associated with MALE or MACE.

CONCLUSIONS

Plasma Lp(a) is independently associated with first and consecutive MALE after iliofemoral endarterectomy. Hence, in patients who undergo iliofemoral endarterectomy, Lp(a) could be considered as a biomarker to enhance risk stratification for future MALE.

Pedal arterial calcification score is associated with the risk of major amputation in chronic limb-threatening ischemia

OBJECTIVE

The medial arterial calcification (MAC) score is a simple metric that describes the burden of inframalleolar calcification using a plain foot radiograph. We hypothesized that a higher MAC score would be independently associated with the risk of major amputation in patients with chronic limb-threatening ischemia (CLTI).

METHODS

We performed a single-institution, retrospective study of 250 patients who had undergone infrainguinal revascularization for CLTI from January 2011 to July 2019 and had foot radiographs available for MAC score calculation. A single blinded reviewer assigned MAC scores of 0 to 5 using two-view minimum plain foot radiographs, with 1 point each for calcification of >2 cm in the dorsalis pedis, plantar, and metatarsal arteries and >1 cm in the hallux and non-hallux digital arteries.

RESULTS

The MAC score was 0 in 36%, 1 in 5.2%, 2 in 8.4%, 3 in 14%, 4 in 14%, and 5 in 21%. The MAC score was trichotomized to facilitate analysis and clinical utility (mild, MAC score 0-1; moderate, MAC score 2-4; and severe, MAC score 5). The variables independently associated with a higher MAC score were male sex, diabetes, end-stage renal disease, and the global limb anatomic staging system pedal score. The MAC score was not associated with the Society for Vascular Surgery WIfI (wound, ischemia, foot infection) grade or overall WIfI stage (P = .58). The median follow-up was 759 days (interquartile range, 264-1541 days). A higher MAC score was significantly associated with the risk of major amputation (P < .0001). In a Cox proportional hazards multiple regression model for major amputation that included the trichotomized MAC score, diabetes, end-stage renal disease, and WIfI stage (1-3 vs 4). The MAC score (MAC score 5: hazard ratio [HR], 4.9; 95% confidence interval [CI], 1.9-13.1; P = .001; MAC score 2-4: HR, 3.4; 95% CI, 1.3-8.8; P = .01) and WIfI stage (WIfI stage 4: HR, 2.1; 95% CI, 1.1-3.9; P = .03) were significantly associated with the risk of major amputation. In the subsets of patients with the most advanced WIfI stage of 3 to 4 (191 of 250; 76%) and patients with diabetes (185 of 250; 74%), the MAC score further stratified the risk of major amputation on univariate and multivariate analyses.

CONCLUSIONS

The MAC score is a simple, practical tool and a strong independent predictor of major amputation in patients with CLTI. It provides novel clinical data that are currently unmeasured using any validated CLTI staging system. The MAC score is a promising standardized measure of inframalleolar disease burden that can be used in conjunction with the WIfI staging system to help improve outcomes stratification and determine the optimal treatment strategies for patients with CLTI.

The association of healthcare disparities and patient-specific factors on clinical outcomes in peripheral artery disease

BACKGROUND

PAD increases the risk of cardiovascular mortality and limb loss, and disparities in treatment and outcomes have been described. However, the association of patient-specific characteristics with variation in outcomes is less well known.

METHODS

Patients with PAD from Duke University Health System (DUHS) between January 1, 2015 and March 31, 2016 were identified. PAD status was confirmed through ground truth adjudication and predictive modeling using diagnosis codes, procedure codes, and other administrative data. Symptom severity, lower extremity imaging, and ankle-brachial index (ABI) were manually abstracted from the electronic health record (EHR). Data was linked to Centers for Medicare and Medicaid Services data to provide longitudinal follow up. Primary outcome was major adverse vascular events (MAVE), a composite of all-cause mortality, myocardial infarction (MI), stroke, lower extremity revascularization and amputation.

RESULTS

Of 1,768 patients with PAD, 31.6% were asymptomatic, 41.2% had intermittent claudication (IC), and 27.3% had chronic limb-threatening ischemia (CLTI). At 1 year, patients with CLTI had higher rates of MAVE compared with asymptomatic or IC patients. CLTI and Medicaid dual eligibility were independent predictors of mortality. CLTI and Black race were associated with amputation.

CONCLUSIONS

Rates of MAVE were highest in patients with CLTI, but patients with IC or asymptomatic disease also had high rates of adverse events. Black and Medicaid dual-eligible patients were disproportionately present in the CLTI subgroup and were at higher risk of amputation and mortality, respectively. Future studies must focus on early identification of high-risk patient groups to improve outcomes in patients with PAD.

The Global Limb Anatomic Staging System (GLASS) for CLTI: Improving Inter-Observer Agreement

Objective: The 2020 Global Vascular Guidelines aim at improving decision making in Chronic Limb-Threatening Ischemia (CLTI) by providing a framework for evidence-based revascularization. Herein, the Global Limb Anatomic Staging System (GLASS) serves to estimate the chance of success and patency of arterial pathway revascularization based on the extent and distribution of the atherosclerotic lesions. We report the preliminary feasibility results and observer variability of the GLASS. GLASS is a part of the new global guideline and posed as a promising additional tool for EBR strategies to predict the success of lower extremity arterial revascularization. This study reports on the consistency of GLASS scoring to maximize inter-observer agreement and facilitate its application. Methods: GLASS separately scores the femoropopliteal (FP) and infrapopliteal (IP) segment based on stenosis severity, lesion length and the extent of calcification within the target artery pathway (TAP). In our stepwise approach, we used two angiographic datasets. Each following step was based on the lessons learned from the previous step. The primary outcome was inter-observer agreement measured as Cohen’s Kappa, scored by two (step 1 + 2) and four (step 3) blinded and experienced observers, respectively. Steps 1 (n = 139) and 2 (n = 50) were executed within a dataset of a Dutch interventional RCT in CLTI. Step 3 (n = 100) was performed in randomly selected all-comer CLTI patients from two vascular centers in the United States. Results: In step 1, kappa values were 0.346 (FP) and 0.180 (IP). In step 2, applied in the same dataset, the use of other experienced observers and a provided TAP, resulted in similar low kappa values 0.406 (FP) and 0.089 (IP). Subsequently, in step 3, the formation of an altered stepwise approach using component scoring, such as separate scoring of calcification and adding a ruler to the images resulted in kappa values increasing to 0.796 (FP) and 0.730 (IP). Conclusion: This retrospective GLASS validation study revealed low inter-observer agreement for unconditioned scoring. A stepwise component scoring provides acceptable agreement and a solid base for further prospective validation studies to investigate how GLASS relates to treatment outcomes.

Long Term Survival and Limb Salvage in Patients With Non-Revascularisable Chronic Limb Threatening Ischaemia

OBJECTIVE

The aim of this study was to provide long term survival and limb salvage rates for patients with non-revascularisable (NR) chronic limb threatening ischaemia (CLTI).

METHODS

This was a retrospective review of prospectively collected data, derived from a randomised controlled trial (JUVENTAS) investigating the use of a regenerative cell therapy. Survival and limb salvage of the index limb in CLTI patients without viable options for revascularisation at inclusion were analysed retrospectively. The primary outcome was amputation free survival, a composite of survival and limb salvage, at five years after inclusion in the original trial.

RESULTS

In 150 patients with NR-CLTI, amputation free survival was 43% five years after inclusion. This outcome was driven by an equal rate of all cause mortality (35%) and amputation (33%). Amputation occurred predominantly in the first year. Furthermore, 33% of those with amputation subsequently died within the investigated period, with a median interval of 291 days.

CONCLUSION

Five years after the initial need for revascularisation, about half of the CLTI patients who were deemed non-revascularisable survived with salvage of the index limb. Although the prospects for these high risk patients are still poor, under optimal medical care, amputation free survival seems comparable with that of revascularisable CLTI patients, while the major amputation rate within one year, especially among NR-CLTI patients with ischaemic tissue loss, is very high.

Impact of Bypass Flow Assessment on Long-Term Outcomes in Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

Transit time flow meter (TTFM) allows quick and accurate intraoperative graft assessment. The main study goal is to evaluate the influence of graft flow measurements on long-term clinical outcomes in patients with chronic limb-threatening ischemia (CLTI) undergoing bellow the knee (BTK) vein bypass surgery.

METHODS

Between January 1st, 1999 and January 1st, 2006, 976 CLTI consecutive patients underwent lower extremity bypass surgery. When applying the exclusion criteria, 249 patients were included in the final analysis. Control measurements were performed at the end of the procedure. Patients were divided according to the mean (more/less than 100 ml/min) and diastolic graft flow (more/less than 40 ml/min) values in four groups. The primary endpoints were a major adverse limb event (male) and primary graft patency.

RESULTS

After the median follow-up of 68 months, a group with the mean graft flow below 100 ml/min and the diastolic graft flow below 40 ml/min had the highest rates of male (χ² = 36.60, DF = 1, P < 0.01, log-rank test) and the worst primary graft patency (χ² = 53.05, DF = 1, P < 0.01, log-rank test).

CONCLUSION

In patients with CLTI undergoing BTK vein bypass surgery, TTFM parameters, especially combined impact of mean graft flow less than 100 ml/min and diastolic graft flow less than 40 ml/min, were associated with an increased risk of poor long-term male and primary graft patency.

Platelet aggregation inhibitor prescription for newly diagnosed peripheral arterial disease in the Netherlands: a cohort study

OBJECTIVES

Pharmacological treatment of peripheral arterial disease (PAD) comprises of antiplatelet therapy (APT), blood pressure control and cholesterol optimisation. Guidelines provide class-I recommendations on the prescription, but there are little data on the actual prescription practices. Our study provides insight into the prescription of medication among patients with PAD in the Netherlands and reports a 'real-world' patient journey through primary and secondary care.

DESIGN

We conducted a cohort study among patients newly diagnosed with PAD between 2010 and 2014.

SETTING

Data were obtained from the PHARMO Database Network, a population-based network of electronic pharmacy, primary and secondary healthcare setting records in the Netherlands. The source population for this study comprised almost 1 million individuals.

PARTICIPANTS

'Newly diagnosed' was defined as a recorded International Classification of Primary Care code for PAD, a PAD-specific WCIA examination code or a diagnosis recorded as free text episode in the general practitioner records with no previous PAD diagnosis record and no prescription of P2Y12 inhibitors or aspirin the preceding year. The patient journey was defined by at least 1 year of database history and follow-up relative to the index date.

RESULTS

Between 2010 and 2014, we identified 3677 newly diagnosed patients with PAD. Most patients (91%) were diagnosed in primary care. Almost half of all patients (49%) had no APT dispensing record. Within this group, 33% received other anticoagulant therapy (vitamin K antagonist or direct oral anticoagulant). Mono-APT was dispensed as aspirin (40% of patients) or P2Y12 inhibitors (2.5% of patients). Dual APT combining aspirin with a P2Y12 inhibitor was dispensed to 8.5% of the study population.

CONCLUSION

Half of all patients with newly diagnosed PAD are not treated conforming to (international) guideline recommendations on thromboembolism prevention through APT. At least 33% of all patients with newly diagnosed PAD do not receive any antithrombotic therapy. Evaluation and improvement of APT prescription and thereby improved prevention of (secondary) cardiovascular events is warranted.

Exercise training for intermittent claudication: a narrative review and summary of guidelines for practitioners

Peripheral artery disease (PAD) is caused by atherosclerotic narrowing of the arteries supplying the lower limbs often resulting in intermittent claudication, evident as pain or cramping while walking. Supervised exercise training elicits clinically meaningful benefits in walking ability and quality of life. Walking is the modality of exercise with the strongest evidence and is recommended in several national and international guidelines. Alternate forms of exercise such as upper- or lower-body cycling may be used, if required by certain patients, although there is less evidence for these types of programmes. The evidence for progressive resistance training is growing and patients can also engage in strength-based training alongside a walking programme. For those unable to attend a supervised class (strongest evidence), home-based or 'self-facilitated' exercise programmes are known to improve walking distance when compared to simple advice. All exercise programmes, independent of the mode of delivery, should be progressive and individually prescribed where possible, considering disease severity, comorbidities and initial exercise capacity. All patients should aim to accumulate at least 30 min of aerobic activity, at least three times a week, for at least 3 months, ideally in the form of walking exercise to near-maximal claudication pain.

Association Between Wearable Device-Based Measures of Physical Frailty and Major Adverse Events Following Lower Extremity Revascularization

IMPORTANCE

Physical frailty is a key risk factor associated with higher rates of major adverse events (MAEs) after surgery. Assessing physical frailty is often challenging among patients with chronic limb-threatening ischemia (CLTI) who are often unable to perform gait-based assessments because of the presence of plantar wounds.

OBJECTIVE

To test a frailty meter (FM) that does not rely on gait to determine the risk of occurrence of MAEs after revascularization for patients with CLTI.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 184 consecutively recruited patients with CLTI at 2 tertiary care centers. After 32 individuals were excluded, 152 participants were included in the study. Data collection was conducted between May 2018 and June 2019.

EXPOSURES

Physical frailty measurement within 1 week before limb revascularization and incidence of MAEs for as long as 1 month after surgery.

MAIN OUTCOMES AND MEASURES

The FM works by quantifying weakness, slowness, rigidity, and exhaustion during a 20-second repetitive elbow flexion-extension exercise using a wrist-worn sensor. The FM generates a frailty index (FI) ranging from 0 to 1; higher values indicate progressively greater severity of physical frailty.

RESULTS

Of 152 eligible participants (mean [SD] age, 67.0 [11.8] years; 59 [38.8%] women), 119 (78.2%) were unable to perform the gait test, while all could perform the FM test. Overall, 53 (34.9%), 58 (38.1%), and 41 (27.0%) were classified as robust (FI <0.20), prefrail (FI ≥0.20 to <0.35), or frail (FI ≥0.35), respectively. Within 30 days after surgery, 24 (15.7%) developed MAEs, either major adverse cardiovascular events (MACE; 8 [5.2%]) or major adverse limb events (MALE; 16 [10.5%]). Baseline demographic characteristics were not significantly different between frailty groups. In contrast, the FI was approximately 30% higher in the group that developed MAEs (mean [SD] score, 0.36 [0.14]) than those who were MAE free (mean [SD] score, 0.26 [0.13]; P = .001), with observed MAE rates of 4 patients (7.5%), 7 patients (12.1%), and 13 patients (31.7%) in the robust, prefrail and frail groups, respectively (P = .004). The FI distinguished individuals who developed MACE and MALE from those who were MAE free (MACE: mean [SD] FI score, 0.38 [0.16]; P = .03; MALE: mean [SD] FI score, 0.35 [0.13]; P = .004) after adjusting by body mass index.

CONCLUSIONS AND RELEVANCE

In this cohort study, measuring physical frailty using a wrist-worn sensor during a short upper extremity test was a practical method for stratifying the risk of MAEs following revascularization for CLTI when the administration of gait-based tests is often challenging.

Impact of obesity on walking capacity and cardiovascular parameters in patients with peripheral artery disease: A cross-sectional study

BACKGROUND

Patients with peripheral artery disease (PAD) present a high prevalence of obesity and metabolic syndrome, as well as diseases related to cardiovascular dysfunction. However, whether obesity influences walking capacity and cardiovascular function in patients with PAD is poorly understood.

OBJECTIVES

The objective of this study was to analyze the impact of obesity on walking capacity and cardiovascular parameters in patients with PAD.

DESIGN

This is a cross-sectional study.

SETTING

Patients were recruited from public hospitals of São Paulo.

METHODS

One-hundred two patients with PAD and symptoms of intermittent claudication were recruited and divided into 2 groups according to their body mass index: normal weight (<25 kg/m²) and overweight/obese (≥25 kg/m²). Patients were submitted to objective (6-minute walk test) and subjective measurements of walking capacity (Walking Impairment Questionnaire). In addition, cardiovascular parameters (office blood pressure, resting heart rate, arterial stiffness, vascular function, and heart rate variability) were obtained.

RESULTS

The speed domain of the Walking Impairment Questionnaire was lower in the overweight/obese group compared to the normal weight group (32 ± 20 vs 21 ± 16, respectively, P < .01). Resting heart rate was higher in overweight/obese patients (61 ± 10 vs 70 ± 12, respectively, P < .01). However, no other walking capacity or cardiovascular parameter variables were related to obesity in patients with PAD.

CONCLUSION

Obesity influences resting heart rate and walking speed in patients with PAD.

External validation of the Vascular Quality Initiative prediction model for survival in no-option chronic limb-threatening ischemia patients

OBJECTIVE

Chronic limb-threatening ischemia (CLTI) is associated with high morbidity and mortality rates. More than 50% of all CLTI patients die within 5 years after presentation. Patient-specific survival prediction is critical for informing treatment strategies, even for those without a clear option for revascularization. We validated a survival prediction model, developed in a revascularized Vascular Quality Initiative (VQI) cohort, in a Western European no-option CLTI cohort.

METHODS

The VQI survival prediction model was applied to the validation cohort (N = 150) to compare estimated mortality and observed mortality at 2 years after baseline. Performance of the VQI model was tested by evaluating discrimination using the receiver operating characteristic area under the curve and calibration using the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

The 2-year survival rate was 79% in the validation cohort compared with 83% in the VQI cohort. Baseline characteristics were significantly different for 13 of 17 variables. The C statistic was 0.86 (95% confidence interval, 0.78-0.95), which indicates good discrimination. The Hosmer-Lemeshow goodness-of-fit test had a P value of .30, which indicates good fit.

CONCLUSIONS

This is the first external validation of the VQI survival prediction model. The good model performance suggests that this model can be used in different CLTI populations, including no-option CLTI, and underlines its contributory role in this challenging population.

The patient presenting with chronic limb-threatening ischaemia. Does diabetes influence presentation, limb outcomes and survival?

Peripheral arterial disease (PAD) confers an elevated risk of major amputation and delayed wound healing in diabetic patients with foot ulcers. The major international vascular societies recently developed evidence-based guidelines for the assessment and management of patients with chronic limb-threatening ischaemia (CLTI). CLTI represents the cohort of diabetic and non-diabetic patients who have PAD which is of sufficient severity to delay wound healing and increase amputation risk. Diabetic patients with CLTI are more likely to present with tissue loss, infection and have less favourable anatomy for revascularization than those without diabetes. Although diabetes is not consistently reported as a strong independent risk factor for limb loss, major morbidity and mortality in CLTI patients, it is impossible in clinical practice to isolate diabetes from comorbidities, such as end-stage renal disease and coronary artery disease which occur more commonly in diabetic patients. Treatment of CLTI in the diabetic patient is complex and should involve a multi-disciplinary team to optimize outcomes. Clinicians should use an integrated approach to management based on patient risk assessment, an assessment of the severity of the foot pathology and a structured anatomical assessment of arterial disease as suggested by the Global Vascular Guidelines for CLTI.

Umbrella review and meta-analysis of antiplatelet therapy for peripheral artery disease

Background

The literature on antiplatelet therapy for peripheral artery disease has historically been summarized inconsistently, leading to conflict between international guidelines. An umbrella review and meta-analysis was performed to summarize the literature, allow assessment of competing safety risks and clinical benefits, and identify weak areas for future research.

Methods

MEDLINE, Embase, DARE, PROSPERO and Cochrane databases were searched from inception until January 2019. All meta-analyses of antiplatelet therapy in peripheral artery disease were included. Quality was assessed using AMSTAR scores, and GRADE analysis was used to quantify the strength of evidence. Data were pooled using random-effects models.

Results

Twenty-eight meta-analyses were included. Thirty-three clinical outcomes and 41 antiplatelet comparisons in 72 181 patients were analysed. High-quality evidence showed that antiplatelet monotherapy reduced non-fatal strokes (3 (95 per cent c.i. 0 to 6) fewer per 1000 patients), In symptomatic patients, it reduced cardiovascular deaths (8 (0 to 16) fewer per 1000 patients), but increased the risk of major bleeding (7 (3 to 14) more events per 1000). In asymptomatic patients, monotherapy reduced non-fatal strokes (5 (0 to 8) fewer per 1000), but had no other clinical benefit. Dual antiplatelet therapy caused more major bleeding after intervention than monotherapy (37 (8 to 102) more events per 1000), with very low-quality evidence of improved endovascular patency (risk ratio 4·00, 95 per cent c.i. 0·91 to 17·68).

Conclusion

Antiplatelet monotherapy has minimal clinical benefit for asymptomatic peripheral artery disease, and limited benefit for symptomatic disease, with a clear risk of major bleeding. There is a lack of evidence to guide antiplatelet prescribing after peripheral endovascular intervention.

Validation of randomized controlled trial-derived models for the prediction of postintervention outcomes in chronic limb-threatening ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) represents the most severe form of peripheral artery disease and has a large impact on quality of life, morbidity, and mortality. Interventions are aimed at improving tissue perfusion and averting amputation and secondary cardiovascular complications with an optimal risk-benefit ratio. Several prediction models regarding postprocedural outcomes in CLTI patients have been developed on the basis of randomized controlled trials to improve clinical decision-making. We aimed to determine model performance in predicting clinical outcomes in selected CLTI cohorts.

METHODS

This study validated the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL), Finland National Vascular registry (FINNVASC), and Prevention of Infrainguinal Vein Graft Failure (PREVENT III) models in data sets from a peripheral artery disease registry study (Athero-Express) and two randomized controlled trials of CLTI in The Netherlands, Rejuvenating Endothelial Progenitor Cells via Transcutaneous Intra-arterial Supplementation (JUVENTAS) and Percutaneous Transluminal Angioplasty and Drug-eluting Stents for Infrapopliteal Lesions in Critical Limb Ischemia (PADI). Receiver operating characteristic (ROC) curve analysis was used to calculate their predictive capacity. The primary outcome was amputation-free survival (AFS); secondary outcomes were all-cause mortality and amputation at 12 months after intervention.

RESULTS

The BASIL and PREVENT III models showed predictive values regarding postintervention mortality in the JUVENTAS cohort with an area under the ROC curve (AUC) of 81% and 70%, respectively. Prediction of AFS was poor to fair (AUC, 0.60-0.71) for all models in each population, with the highest predictive value of 71% for the BASIL model in the JUVENTAS population. The FINNVASC model showed the highest predictive value regarding amputation risk in the PADI population with AUC of 78% at 12 months.

CONCLUSIONS

In general, all models performed poor to fair in predicting mortality and amputation. Because the BASIL model performed best in predicting AFS, we propose use of the BASIL model to aid in the clinical decision-making process in CLTI. However, improvements in performance have to be made for any of these models to be of real additional value in clinical practice.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

The burden of critical limb ischemia: a review of recent literature

Peripheral arterial disease is a chronic vascular disease characterized by impaired circulation to the lower extremities. Its most severe stage, known as critical limb ischemia (CLI), puts patients at an increased risk of cardiovascular events, amputation, and death. The objective of this literature review is to describe the burden of disease across a comprehensive set of domains—epidemiologic, clinical, humanistic, and economic—focusing on key studies published in the last decade. CLI prevalence in the United States is estimated to be approximately 2 million and is likely to rise in the coming years given trends in important risk factors such as age, diabetes, and smoking. Hospitalization for CLI patients is common and up to 60% are readmitted within 6 months. Amputation rates are unacceptably high with a disproportionate risk for certain demographic and socioeconomic groups. In addition to limb loss, CLI patients also have reduced life expectancy with mortality typically exceeding 50% by 5 years. Given the poor clinical prognosis, it is unsurprising that the quality of life burden associated with CLI is significant. Studies assessing quality of life in CLI patients have used a variety of generic and disease-specific measures and all document a substantial impact of the disease on the patient’s physical, social, and emotional health status compared to population norms. Finally, the poor clinical outcomes and increased medical resource use lead to a considerable economic burden for national health care systems. However, published cost studies are not comprehensive and, therefore, likely underestimate the true economic impact of CLI. Our summary documents a sobering assessment of CLI burden—a poor clinical prognosis translating into diminished quality of life and high costs for millions of patients. Continued prevention efforts and improved treatment strategies are the key to ameliorating the substantial morbidity and mortality associated with this disease.

Multidisciplinary Treatment for Critical Limb Ischemia in Peripheral Arterial Disease

Critical limb ischemia (CLI) is a severe blockage of the arteries to the lower limbs characterized by poor prognoses for both salvage of the lower limb and patient survival. Accordingly, CLI must be diagnosed and treated appropriately from the earliest possible stage. To do so, multidisciplinary treatment not only by vascular surgeons but also by many other doctors and medical staff is necessary. Accurate diagnosis is indispensable to appropriate treatment of CLI; thus, the definitions in the recently issued new guidelines for CLI treatment are reviewed. The multidisciplinary treatment of CLI should be recognized as three elements: namely, multidisciplinary treatment to salvage the lower limb, to improve of survival prognosis, and to prevent CLI occurrence. In all of these events, team medicine administered by expert staff is indispensable. The specialist must have not only profound knowledge of his/her field of specialty but also professional skills and the ability to cooperate with other departments. A multidisciplinary treatment approach that combines the abilities of many specialists for treating severely ischemic limbs in patients with peripheral arterial disease is expected to improve both limb salvage and patient survival and should be promoted in daily clinical settings. (This is a translation of Jpn J Vasc Surg 2018; 27: 507–512.)

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

On-Treatment Platelet Reactivity is a Predictor of Adverse Events in Peripheral Artery Disease Patients Undergoing Percutaneous Angioplasty

OBJECTIVES

Few data are available on the association between a different entity of platelet inhibition on antiplatelet treatment and clinical outcomes in patients with peripheral artery disease (PAD). The aim of this study was to evaluate the degree of on-treatment platelet reactivity, and its association with ischaemic and haemorrhagic adverse events at follow up in PAD patients undergoing percutaneous transluminal angioplasty (PTA).

METHODS

In this observational, prospective, single centre study, 177 consecutive patients with PAD undergoing PTA were enrolled, and treated with dual antiplatelet therapy with aspirin and a P2Y12 inhibitor. Platelet function was assessed on blood samples obtained within 24 h from PTA by light transmission aggregometry (LTA) using arachidonic acid (AA) and adenosine diphosphate (ADP) as agonists of platelet aggregation. High on-treatment platelet reactivity (HPR) was defined by LTA ≥ 20% if induced by AA, and LTA ≥ 70% if induced by ADP. Follow up was performed to record outcomes (death, major amputation, target vessel re-intervention, acute myocardial infarction and/or myocardial revascularisation, stroke/TIA, and bleeding).

RESULTS

HPR by AA and HPR by ADP were found in 45% and 32% of patients, respectively. During follow up (median duration 23 months) 23 deaths (13%) were recorded; 27 patients (17.5%) underwent target limb revascularisation (TLR), two (1.3%) amputation, and six (3.9%) myocardial revascularisation. Twenty-four patients (15.6%) experienced minor bleeding. On multivariable analysis, HPR by AA and HPR by ADP were independent predictors of death [HR 3.8 (1.2-11.7), p = .023 and HR 4.8 (1.6-14.5), p = .006, respectively]. The median value of LTA by ADP was significantly lower in patients with bleeding complications than in those without [26.5% (22-39.2) vs. 62% (44.5-74), p < .001). LTA by ADP ≤ 41% was independently associated with bleeding HR 14.6 (2.6-24.0), p = .001] on multivariable analysis.

CONCLUSIONS

In this study a high prevalence of on-clopidogrel and aspirin high platelet reactivity was found, which was significantly associated with the risk of death. Conversely, a low on-clopidogrel platelet reactivity was associated with a higher risk of bleeding. These results document that the entity of platelet inhibition is associated with both thrombotic and bleeding complications in PAD patients.

Hospital and Institutionalisation Care Costs after Limb and Visceral Ischaemia Benchmarked Against Stroke: Long-Term Results of a Population Based Cohort Study

OBJECTIVE/BACKGROUND

There are few published data on the acute care or long-term costs after acute/critical limb or visceral ischaemia (ACLVI) events. Using data from patients with acute events in a population based incidence study (Oxford Vascular Study), the present study aimed to determine the long-term costs after an ACLVI event.

METHODS

All patients with first ever incident ACLVI from 2002 to 2012 were included. Analysis was based on follow up until January 2017, with all patients having full 5 year follow up. Multivariate regressions were used to assess baseline and subsequent predictors of total 5 year hospital care costs. Overall costs after an ACLVI event were benchmarked against those after stroke in the same population, during the same period.

RESULTS

Among 351 patients with an ACLVI event, mean 5 year total care costs were €35,211 (SD 50,500), of which €6443 (18%) were due to long-term institutionalisation. Costs differed by type of event (acute visceral ischaemia €16,476; acute limb ischaemia €24,437; critical limb ischaemia €46,281; p < 0.001). Results of the multivariate analyses showed that patients with diabetes and those undergoing above knee amputations incurred additional costs of €11,804 (p = 0.014) and €25,692 (p < 0.001), respectively. Five year hospital care costs after an ACLVI event were significantly higher than after stroke (€28,768 vs. €22,623; p = 0.004), but similar after including long-term costs of institutionalisation (€35,211 vs. €35,391; p = 0.957).

CONCLUSION

Long-term care costs after an ACLVI event are considerable, especially after critical limb ischaemia. Hospital care costs were significantly higher than for stroke over the long term, and were similar after inclusion of costs of institutionalisation.