Outcomes of dialysis patients with critical limb ischemia after revascularization compared with patients with normal renal function

Outcomes of chronic limb-threatening ischemia revascularization in patients with chronic kidney disease in the BEST-CLI trial

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with chronic kidney disease (CKD) has a high risk of poor outcomes. We aimed to compare the outcomes of lower extremity revascularization in patients with CLTI stratified by CKD severity in patients enrolled in the prospective, randomized Best Endovascular vs Best Surgical Therapy in Patients with CLTI (BEST-CLI) trial.

METHODS

The BEST-CLI trial dataset was queried to categorize patients into three groups according to CKD stage. Group A includes non-CKD and CKD stages <3; group B includes stage 3 and stage 4 CKD patients; and group C includes stage 5 CKD and dialysis-dependent patients. Furthermore, spline modeling was performed across the range of estimated glomerular filtration rate (eGFR, mL/min/1.73 m2) observed in study participants to identify a threshold eGFR that impacted the primary trial outcomes: major adverse limb events (MALEs; defined as above-ankle amputation or major reintervention) or all-cause mortality, by surgical or endovascular revascularization (as-treated analysis). Kaplan-Meier and multivariate Cox regression analyses were used to assess association of CKD risk groups with the outcomes.

RESULTS

A total of 1797 patients were included. Group C patients had double the risk of amputation (hazard ratio [HR], 2.13; P < .001), MALE, or all-cause mortality (HR, 2.05; P < .001) and more than triple the risk of all-cause mortality (HR, 3.40; P < .001) compared with group A. In dialysis-dependent patients, endovascular therapy was associated with better survival, but twice the risk of reintervention compared with surgical revascularization. According to spline model analysis, hazard of MALE or all-cause mortality increased sharply at eGFR <30. The hazard ratios for eGFR <30 vs ≥60 were 2.03 (95% confidence interval [CI], 1.68-2.43; P < .001) and 3.46 (95% CI, 2.80-4.27; P < .001) for MALE and mortality, respectively. At eGFR <30, there was no difference in the primary outcome by treatment received (surgical or endovascular revascularization).

CONCLUSIONS

The progressive nature of renal impairment in patients with CLTI threatens their survival and limb salvage and may reduce the relative benefit of open vs endovascular revascularization seen in the overall BEST-CLI trial population. In dialysis-dependent patients, endovascular therapy was associated with lower mortality but increased reintervention rate.

Effects of dialysis on peripheral arterial disease

End-stage renal disease is an independent risk factor for the development of peripheral arterial disease, with considerably worse outcomes in patients with concomitant diseases. It is important to realize the widespread, yet frequently asymptomatic, nature of peripheral arterial disease in patients with end-stage renal disease due to the presence of other comorbidities that decrease activity levels and sensation to allow for early recognition and timely medical management to try and mitigate otherwise poor outcomes. Despite their high risk, properly selected patients derive benefit from revascularization; both open and endovascular approaches provide similar outcomes in terms of overall survival, amputation-free survival, and limb salvage, with perhaps a slight preference toward open repair. This narrative review of the literature evaluates the epidemiology, pathophysiology, outcomes, and management strategies that provide the best possible outcomes for patients with peripheral arterial disease and end-stage renal disease.

The effects of hemodialysis on the cardiovascular system

Chronic kidney disease and dialysis-dependent end-stage renal disease are increasing in prevalence in the United States. The costs associated with end-stage renal disease management comprise approximately 1% of the federal government's annual budget. Chronic kidney disease and end-stage renal disease cause significant derangements of the cardiac and vascular system. Pathophysiologic hallmarks include alterations of the renin-angiotensin system, chronically increased sympathetic tone, calcium and phosphate imbalance, pro-inflammatory cytokine release, and uremic toxin accumulation. This results in several pathologies specific to the cardiac and vascular systems, which will each be reviewed separately herein.

Prognostic Value of Hospital Frailty Risk Score and Clinical Outcomes in Critical Limb-Threatening Ischemia and End-Stage Kidney Disease

BACKGROUND

End-stage kidney disease (ESKD) is commonly associated with critical limb-threatening ischemia (CLTI) and frailty. Yet there are no specific tools to predict outcomes of CLTI in ESKD, particularly those that incorporate frailty. We aimed to assess the utility of the medical record-based Hospital Frailty Risk (HFR) score in predicting outcomes of CLTI in ESKD.

METHODS AND RESULTS

We identified patients with ESKD diagnosed with CLTI from the US Renal Data System from 2015 to 2018. These patients were categorized into 3 frailty risk groups on the basis of their HFR scores: low (<5), intermediate (5-10), high-risk (>10), and on the basis of whether they underwent revascularization (endovascular revascularization [ER]/surgical revascularization [SR]) or not (no revascularization). Primary outcomes of interest included in-hospital composite of death or major amputation and in-hospital death. We included 49 454 eligible patients, with ER/SR cohort including 19.8% (n=9777). A total of 88.4% (ER/SR) and 90.0% (no revascularization) were frail on the HFR scale. We found a nonlinear association between HFR score and in-hospital adverse outcomes. In both cohorts, intermediate and high-risk HFR scores were associated with greater risk of in-hospital death (high-risk, ER/SR: odds ratio, 2.7 [95% CI, 1.6-4.8]; P<0.0001; no revascularization: odds ratio, 7.8 [95% CI, 5.3-11.6]; P<0.01) and composite of in-hospital major amputation or death (high-risk, ER/SR: odds ratio, 2.4 [95% CI, 1.9-3.1]; P<0.0001; no revascularization: odds ratio, 1.7 [95% CI, 1.5-1.9]; P<0.0001).

CONCLUSIONS

The HFR score can predict risk of in-hospital death and composite of death or major amputation in patients with ESKD and CLTI. Further data are needed to determine the utility of the HFR score in this population.

Clinical outcomes and risk factors associated with drug-coated balloon treatment for femoropopliteal artery disease in patients on maintenance hemodialysis

The effect of drug-coated balloons (DCB) on hemodialysis (HD) in patients with femoropopliteal (FP) disease remains uncertain. This study aimed to investigate the outcomes of DCB therapy in patients with FP artery disease on HD. A total of 185 patients with FP lesions (140 HD patients) who underwent DCB treatment were included in the study. The incidence of restenosis and target lesion revascularization (TLR) at 12 months were measured. Risk factors for TLR were also investigated. The mean age was 71.7 years, and diabetes was observed in 82.3% of patients. The mean duration of receiving dialysis was 8.8 years. The mean lesion length was 11.0 cm, and approximately half of the lesions were severely calcified. Severe dissection after DCB therapy was observed in 19.5% of patients. During the follow-up period, 74 restenosis, 68 TLRs, 8 major amputations, and 28 deaths were observed. The freedom rates from restenosis and TLR at 12 months were 63.8% and 71.3%, respectively. The freedom rates after low- and high-dose DCB at 12 months were 61.9% and 70.6% for restenosis (P = 0.49) and 66.4% and 79.4% for TLR (P = 0.095), respectively. Independent risk factors for TLR at 12 months of age were diabetes, chronic limb-threatening ischemia, and severe calcification. When patients were divided into four groups according to the number of these three risk factors, the rates of freedom from TLR at 12 months were 100%, 94.8%, 76.7%, and 30.3% in the groups with no risk factors, any one risk factor, any two risk factors, and all risk factors, respectively (P < 0.0001). Clinical outcomes after endovascular therapy in HD patients with FP disease remain unsatisfactory, even if they are treated with DCB. In particular, patients on HD with diabetes, chronic limb-threatening ischemia, and severe calcification have poor outcomes.

Long-term clinical outcomes of arterial bypass and the factors independently associated with the primary patency in patients with suprainguinal arterial occlusion

INTRODUCTION

Aortoiliac occlusive disease and iliofemoral occlusion are impact patient quality of life, cause limb loss and mortality. The aim of this study was to investigate the long-term clinical outcomes of arterial bypass, and the factors associated with the outcomes.

METHOD

This retrospective chart/image review included all types of arterial bypass procedures performed for suprainguinal arterial occlusion during January 2004 to December 2017. The primary outcome was the primary patency. The secondary outcomes were the secondary patency, amputation-free survival, overall survival and the factors associated with the outcomes.

RESULT

A total of 135 patients (107 males) were included. The median age was 65 years. The 1-year, 5-year, and 10-year primary patency rates were 74.3%, 65.7%, and 55.6%, respectively, with independent predictors of poor outcomes being underlying cerebrovascular disease (p = 0.003) and postoperative graft infection (p = 0.016). Secondary patency rates at 1-year, 5-year, and 10-year intervals were 90.1%, 87.1%, and 77.8%, respectively, with independent predictors of poor outcomes being underlying cardiovascular disease (p = 0.013) and postoperative acute kidney injury (p = 0.010). Amputation-free survival rates at 1-year, 5-year, and 10-year intervals were 77.1%, 71.6%, and 66.0%, respectively, with the independent predictor of poor outcome being preoperative foot infection (p = 0.013). Overall survival rates at 1-year, 5-year, and 10-year intervals were 84.4%, 58.6%, and 35.3%, respectively, with independent predictors of poor outcomes being chronic kidney disease (p = 0.030) and postoperative myocardial infarction (p = 0.018). However, antiplatelet therapy emerged as an independent predictor of favorable overall survival outcomes (p = 0.034).

CONCLUSION

Our results showed the primary patency rates of arterial bypass to be relatively low at our center; however, most grafts could be saved with high secondary patency. Both disease-associated factors and patient condition-associated factors were found to influence the outcomes of this fragile patient population.

The Double Burden: Deciphering Chronic Limb-Threatening Ischemia in End-Stage Renal Disease

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) poses significant challenges in clinical management due to its unique pathology and poor treatment outcomes. This review calls for a tailored classification and risk assessment for these patients to guide better revascularization choices with early minor amputation as a first-line strategy in advanced stages.

METHODS

This review consolidates key findings from recent literature on CLTI in ESRD, focusing on disease mechanisms, treatment options, and patient outcomes. It evaluates the literature to clarify the decision-making process for managing CLTI in ESRD.

RESULTS

CLTI in ESRD patients often results in worse clinical outcomes, such as nonhealing wounds, increased limb loss, and higher mortality rates. While the literature reveals ongoing debates regarding the optimal revascularization method, recent retrospective studies and meta-analyses suggest potential benefits of endovascular treatment (EVT) over open bypass surgery (OB) in reducing mortality and wound complications, with comparable amputation-free survival rates.

CONCLUSIONS

The selection of revascularization methods in ESRD patients with CLTI is complex, necessitating individualized strategies. The importance of early detection and timely intervention is critical to decelerate disease progression and improve revascularization outcomes. There is a shift in these treatment strategies toward less invasive endovascular procedures, acknowledging the limitations these patients face with open revascularization surgeries. Considering early minor amputations after revascularization could prevent worse consequences, reflecting a shift in the approach to managing CLTI in ESRD patients.

Validation of JCLIMB, SPINACH, and VQI Calculators for Prediction of Two Year Survival in Patients With Chronic Limb Threatening Ischaemia After Infra-Inguinal Surgical or Endovascular Revascularisation

OBJECTIVE

This study aimed to evaluate three survival prediction models: the JAPAN Critical Limb Ischaemia Database (JCLIMB), Surgical Reconstruction Versus Peripheral Intervention in Patients With Critical Limb Ischaemia (SPINACH), and Vascular Quality Initiative (VQI) calculators.

METHODS

Multicentre data of patients who underwent infrainguinal revascularisation for chronic limb threatening ischaemia between 2018 and 2021 were analysed retrospectively. The prediction models were validated using a calibration plot analysis with the intercept and slope. The discrimination was evaluated using area under the curve (AUC) analysis. The observed two year overall survival (OS) was evaluated by the Kaplan - Meier method. The two year OS predicted by each model at < 50%, 50 - 70%, and > 70% was defined as high, medium, and low risk, respectively.

RESULTS

A total of 491 patients who underwent infra-inguinal revascularisation were analysed. The rates of surgical revascularisation, endovascular therapy, and hybrid therapy were 26.5%, 70.1%, and 5.5%, respectively. The average age was 75.6 years, and the percentages of patients with diabetes mellitus and dialysis dependent end stage renal disease were 66.6% and 44.6%, respectively. The tissue loss rate was 85.7%. The intercept and slope were -0.13 and 1.18 for the JCLIMB, 0.11 and 0.82 for the SPINACH, and -0.15 and 1.10 for the VQI. The AUC for the two year OS of JCLIMB, SPINACH, and VQI were 0.758, 0.756, and 0.740, respectively. The observed two year OS rates of low, medium, and high risk using the JCLIMB calculator were 80.1%, 61.1%, and 28.5%, respectively (p < .001), using the SPINACH calculator were 81.0%, 57.0%, and 38.1%, respectively (p < .001), and using the VQI calculator were 77.8%, 45.8%, and 49.6%, respectively (p < .001).

CONCLUSION

The JCLIMB, SPINACH, and VQI survival calculation models were useful, although the OS predicted by the VQI model appeared to be lower than the observed OS.

Comparison of limb outcomes between bypass surgery and endovascular therapy in dialysis-dependent and -independent patients with chronic limb-threatening ischemia

OBJECTIVE

To examine limb salvage (LS) and wound healing in dialysis-dependent and -independent patients with chronic limb-threatening ischemia (CLTI) after infrainguinal bypass surgery or endovascular therapy (EVT).

METHODS

We retrospectively analyzed the multi-center data of patients who underwent infrainguinal revascularization for CLTI with Wound, Ischemia, and foot Infection (WIfI) stage 2 to 4 between 2015 and 2020. The primary endpoint was LS. The secondary endpoint included wound healing, amputation-free survival (AFS), periprocedural complications, and 2-year survival. Comparison of these outcomes were made after propensity score matching.

RESULTS

We analyzed 252 dialysis-dependent (318 limbs) and 305 dialysis-independent (354 limbs) patients. Propensity score matching extracted 202 pairs with no significant differences in characteristics. The LS rate in bypass surgery was better than that in EVT in dialysis-dependent patients (P < .001). There was no significant difference in the LS rates between bypass surgery and EVT in dialysis-independent patients (P = .168). The wound healing rate of bypass surgery was better than that of EVT both dialysis-dependent and -independent patients with CLTI. The AFS rate of bypass surgery was better than that of EVT in dialysis-dependent patients (P < .001). There was no significant difference in the AFS rates between bypass surgery and EVT in dialysis-independent patients (P = .099). There was no significant difference in the occurrence of Clavien-Dindo ≥ IV and V between bypass surgery and EVT in dialysis-dependent and -independent patients. Age ≥75 years, serum albumin levels <3.5 g/dL, and non-ambulatory status were risk factors for 2-year mortality in dialysis-dependent patients. The 2-year survival rates in dialysis-dependent patients with risk factors of 0, 1, 2, and 3 were 82.5%, 67.1%, 49.5%, and 10.2%, respectively (P < .001).

CONCLUSIONS

For LS and wound healing, bypass surgery was preferred for revascularization in dialysis-dependent patients with WIfI stage 2 to 4. Although dialysis dependency was one of the risk factors for 2-year mortality, dialysis-dependent patients, who have 0 to 1 risk factors, may benefit from bypass surgery, as 2-year survival of >50% is expected.

Association between End-Stage Renal Disease and Major Adverse Limb Events after Peripheral Vascular Intervention

PURPOSE

To examine the effect of end-stage renal disease (ESRD) on the likelihood of major adverse limb events (MALEs) in patients with Rutherford Category 4-6 critical limb ischemia (CLI) who underwent percutaneous vascular intervention (PVI).

MATERIALS AND METHODS

Two contemporaneous cohorts of patients who underwent PVI for symptomatic CLI from 2012 to 2022, differing in ESRD status, were matched using propensity score methods. This database identified 628 patients who underwent 1,297 lower extremity revascularization procedures; propensity score matching yielded 147 patients (180 limbs, 90 limbs in each group). Kaplan-Meier and Cox proportional hazard analyses were used to assess the effect of ESRD status on MALEs, stratified into major amputation (further stratified into above-knee amputation and below-knee amputation [BKA]) and reintervention (PVI or bypass).

RESULTS

After PVI, 31.3% of patients in the matched cohorts experienced a MALE (45.7% ESRD vs 18.2% non-ESRD), and 15.6% experienced a major amputation (27.1% ESRD vs 5.2% non-ESRD). Cox proportional hazards analysis revealed that ESRD was an independent predictor of MALE (hazard ratio [HR], 3.15; 95% CI, 1.58-6.29; P = .001), major amputation (HR, 7.00; 95% CI, 2.06-23.79; P = .002), and BKA (HR, 7.56; 95% CI, 1.71-33.50; P = .008).

CONCLUSIONS

ESRD is strongly predictive of MALE and major amputation risk, specifically BKA, in patients undergoing PVI for Rutherford Category 4-6 CLI. These patients warrant closer follow-up, and new methods may become necessary to predict and further reduce their amputation risk.

Treatment Location Variation for Chronic Limb-Threatening Ischemia in Patients With Kidney Failure

INTRODUCTION

End-stage kidney disease (ESKD) is an established risk factor for chronic limb-threatening ischemia (CLTI). Procedural location for ESKD patients has not been well described. This study aims to examine variation in index procedural location in ESKD versus non-ESKD patients undergoing peripheral vascular intervention for CLTI and identify preoperative risk factors for tibial interventions.

METHODS

Chronic limb-threatening ischemia (CLTI) patients were identified in the Vascular Quality Initiative (VQI) peripheral vascular intervention dataset. Patient demographics and comorbidities were compared between patients with and without ESKD and those undergoing index tibial versus nontibial interventions. A multivariable logistic regression evaluating risk factors for tibial intervention was conducted.

RESULTS

A total of 23,480 procedures were performed on CLTI patients with 13.6% (n = 3154) with ESKD. End-stage kidney disease (ESKD) patients were younger (66.56 ± 11.68 versus 71.66 ± 12.09 y old, P = 0.019), more often Black (40.6 versus 18.6%, P < 0.001), male (61.2 versus 56.5%, P < 0.001), and diabetic (81.8 versus 60.0%, P < 0.001) than non-ESKD patients. Patients undergoing index tibial interventions had higher rates of ESKD (19.4 versus 10.6%, P < 0.001) and diabetes (73.4 versus 57.5%, P < 0.001) and lower rates of smoking (49.9 versus 73.0%, P < 0.001) than patients with nontibial interventions. ESKD (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.52-1.86, P < 0.001), Black race (OR 1.19, 95% CI 1.09-1.30, P < 0.001), and diabetes (OR 1.82, 95% CI 1.71-2.00, P < 0.001) were risk factors for tibial intervention.

CONCLUSIONS

Patients with ESKD and CLTI have higher rates of diabetes and tibial disease and lower rates of smoking than non-ESKD patients. Tibial disease was associated with ESKD, diabetes, and Black race.

Pathological Analysis of Medial and Intimal Calcification in Lower Extremity Artery Disease: Impact of Hemodialysis

Background

The prevalence and degree of lower extremity artery disease in hemodialysis (HD) patients is higher than in the general population. However, the pathological features have not yet been evaluated.

Objectives

The aim of the study was: 1) to compare lesion characteristics of lower extremity artery disease in HD vs non-HD patients; and 2) to determine factors associated with severe medial calcification.

Methods

Seventy-seven lower limb arteries were assessed from 36 patients (median age 77 years; 23 men; 21 HD and 15 non-HD) who underwent autopsy or lower limb amputation. Arteries were serially cut at 3- to 4-mm intervals creating 2,319 histological sections. Morphometric analysis and calcification measurements were performed using ZEN software. Calcification with a circumferential angle (arc) ≥180° was defined as severe calcification. Multivariable logistic regression was used to identify risk factors for severe medial calcification.

Results

The degree of the medial calcification arc was significantly higher in the HD group compared to the non-HD group (P < 0.0001). In the multivariable analysis, HD was associated with severe medial calcification in below-the-knee lesions (OR: 17.1; P = 0.02). The degree of intimal calcification in above-the-knee lesions was also significantly higher in HD patients with a higher prevalence of advanced atherosclerotic plaque (P = 0.02). The prevalence of severe bone formation was more common in the HD patients (P = 0.01).

Conclusions

Hemodialysis patients demonstrated a higher degree of medial and intimal calcification compared with non-HD patients. The difference was more prominent in the medial calcification of below-the-knee lesions.

Differences in Long-Term Outcomes in End-Stage Kidney Disease Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

End-stage kidney disease (ESKD) is a risk factor for peripheral arterial disease and major adverse limb events following infra-inguinal bypass. Despite comprising an important patient population, ESKD patients are rarely analyzed as a subgroup and are underrepresented in vascular surgery guidelines. This study aims to compare the long-term outcomes of patients with and without ESKD undergoing endovascular peripheral vascular intervention (PVI) for chronic limb-threatening ischemia (CLTI).

METHODS

CLTI patients with and without ESKD from 2007-2020 were identified in the Vascular Quality Initiative PVI dataset. Patients with prior bilateral interventions were excluded. Patients undergoing femoral-popliteal and tibial interventions were included. Mortality, reintervention, amputation, and occlusion rates at 21 months following intervention were examined. Statistical analyses were completed with the t-test, chi-square, and Kaplan-Meier curves.

RESULTS

The ESKD cohort was younger (66.4 ± 11.8 vs. 71.6 ± 12.1 years, P < 0.001) with higher rates of diabetes (82.2 vs. 60.9%, P < 0.001) the non-ESKD cohort. Long-term follow-up was available for 58.4% (N = 2,128 procedures) of ESKD patients and 60.8% (N = 13,075 procedures) of non-ESKD patients. At 21 months, ESKD patients had a higher mortality (41.7 vs. 17.4%, P < 0.001) and a higher amputation rate (22.3 vs. 7.1%, P < 0.001); however, they had a lower reintervention rate (13.2 vs. 24.6%, P < 0.001).

CONCLUSIONS

CLTI patients with ESKD have worse long-term outcomes at 2 years following PVI than non-ESKD patients. Mortality and amputation are higher with ESKD, while the reintervention rate is lower. Development of guidelines within the ESKD population has the potential to improve limb salvage.

The Effect of Chronic and End Stage Renal Disease on Long-term Outcomes after Infrainguinal Bypass

OBJECTIVES

Patients undergoing infrainguinal bypass for chronic limb threatening ischemia (CLTI) with renal dysfunction are at an increased risk for perioperative and long-term morbidity and mortality. Our goal was to examine perioperative and 3-year outcomes after lower extremity bypass for CLTI stratified by kidney function.

METHODS

A retrospective, single-center analysis of lower extremity bypass for CLTI was performed between 2008 and 2019. Kidney function was categorized as normal (estimated glomerular filtration rate (eGFR) ≥60ml/min/1.73m²), chronic kidney disease (CKD) (eGFR15-59ml/min/1.73m²), and end stage renal disease (ESRD) (eGFR<15ml/min/1.73m²). Kaplan-Meier and multivariable analysis were performed.

RESULTS

There were 221 infrainguinal bypasses performed for CLTI. Patients were classified by renal function as normal (59.7%), CKD (24.4%), and ESRD (15.8%). Average age was 66 years and 65% were male. Overall, 77% had tissue loss with 9%, 45%, 24%, and 22% being Wound, Ischemia, and foot Infection (WIfI) stages 1-4, respectively. The majority (58%) of bypass targets were infrapopliteal and 58% used ipsilateral greater saphenous vein. The 90-day mortality and readmission rates were 2.7% and 49.8%, respectively. ESRD, compared to CKD and normal renal function, respectively, had the highest 90-day mortality (11.4% vs. 1.9% vs. .8%, P=.002) and 90-day readmission (69% vs. 55% vs. 43%, P=.017). On multivariable analysis, ESRD, but not CKD, was associated with higher 90-day mortality (OR 16.9, 95% CI 1.83-156.6, P=.013) and 90-day readmission (OR 3.02, 95% CI 1.2-7.58, P=.019). Kaplan Meier 3-year analysis showed no difference between groups for primary patency or major amputation, however ESRD, compared to CKD and normal renal function, respectively, had worse primary-assisted patency (60% vs. 76% vs. 84%, P=.03) and survival (72% vs. 96% vs. 94%, P=.001). On multivariable analysis, ESRD and CKD were not associated with 3-year primary patency loss/death, but ESRD was associated with higher primary-assisted patency loss (HR 2.61, 95% CI 1.23-5.53, P=.012). ESRD and CKD were not associated with 3-year major amputation/death. ESRD was associated with higher 3-year mortality (HR 4.95, 95% CI 1.52-16.2, P=.008) while CKD was not.

CONCLUSION

ESRD, but not CKD, was associated with higher perioperative and long-term mortality after lower extremity bypass for CLTI. Although ESRD was associated with lower long-term primary-assisted patency, there were no differences in loss of primary patency or major amputation.

Impact of Statins on Survival and Limb Salvage in Patients Undergoing Peripheral Endovascular Intervention for Chronic Limb-Threatening Ischemia

BACKGROUND

Statin therapy is recommended in all patients with peripheral arterial disease (PAD). Its impact on reduction in mortality has been well-documented, yet effect on limb-specific outcomes has been less conclusive. Differences among PAD subgroups or variability of statin use may contribute to the inconsistent findings. We evaluated statin use in patients who underwent peripheral endovascular intervention (PVI) for chronic limb-threatening ischemia (CLTI) and its impact on overall survival (OS), amputation-free survival (AFS) and limb salvage (LS).

METHODS

The national Vascular Quality Initiative was queried for the index PVI for CLTI during the period 2010-2016; follow-up (FU) through 2020. Demographics, comorbidities, operative details, and FU status were recorded. Patients were categorized as E-Statin: statin use pre-PVI through discharge (D/C) and FU or N-Statin: No statins pre-PVI, at D/C or any time during FU. The propensity score matched model (PSM) was constructed. Groups were compared using chi-square, Kaplan-Meier survival and Cox regression analysis.

RESULTS

There were 9,089 index PVI in 8,402 patients; E-Statin: 7149 index PVI in 6,591 patients; and N-Statin: 1940 index PVI in 1811 patients. The mean age was 69 ± 12 years and 58% were male. Statin use was associated with improved 3-year OS-E Statin: 92.9% ± 0.9 versus N Statin: 91.1% ± 2.2%; P = 0.003; hazard ratio (HR): Exp (B) (95% confidence interval): 0.66 (0.44-0.99); P = 0.047 and remained significant following PSM: E Statin: 95.1% ± 0.2% versus 90.8% ± 0.3%; P = 0.02; HR: 0.50 (0.27-0.92); P = 0.025. No significant differences in 3-year LS or AFS were noted between the prematched groups; LS: E Statin: 83.7% ± 0.8 versus N Statin: 84.0% ± 1.7%; P = 0.89; HR: 1.09 (0.88-1.35); P = 0.44; AFS-E Statin: 77.2% ± 1.1% versus 76.1% ± 2.5%; P = 0.17; HR: 0.97 (0.79-1.18); P = 0.74. or following PSM: AFS: 80.2% ± 2.8% vs. 74.7% ± 3.9%; P = 0.53, HR: 0.92 (0.72-1.19); P = 0.54; LS 85.3% ± 1.9% vs. 83.5% ± 2.6%; P = 0.51, HR: 1.08 (0.83-1.4); P = 0.57. Statins significantly improved LS among those with renal failure: 67.8% ± 2.6% vs. 59.7% ± 4.4%; P = 0.003; HR: 56 (0.40-0.79); P = 0.001.

CONCLUSIONS

Statins are independently associated with improved OS in patients who undergo PVI for CLTI and should be considered for all barring intolerance. Statin use was associated with improved LS in patients with end-stage renal disease. Additional research is needed in this area, particularly, the impact of statin therapy in high-risk CLTI subgroups.

Transcatheter Arterialization of Deep Veins in Chronic Limb-Threatening Ischemia

BACKGROUND

Approximately 20% of patients with chronic limb-threatening ischemia have no revascularization options, leading to above-ankle amputation. Transcatheter arterialization of the deep veins is a percutaneous approach that creates an artery-to-vein connection for delivery of oxygenated blood by means of the venous system to the ischemic foot to prevent amputation.

METHODS

We conducted a prospective, single-group, multicenter study to evaluate the effect of transcatheter arterialization of the deep veins in patients with nonhealing ulcers and no surgical or endovascular revascularization treatment options. The composite primary end point was amputation-free survival (defined as freedom from above-ankle amputation or death from any cause) at 6 months, as compared with a performance goal of 54%. Secondary end points included limb salvage, wound healing, and technical success of the procedure.

RESULTS

We enrolled 105 patients who had chronic limb-threatening ischemia and were of a median age of 70 years (interquartile range, 38 to 89). Of the patients enrolled, 33 (31.4%) were women and 45 (42.8%) were Black, Hispanic, or Latino. Transcatheter arterialization of the deep veins was performed successfully in 104 patients (99.0%). At 6 months, 66.1% of the patients had amputation-free survival. According to Bayesian analysis, the posterior probability that amputation-free survival at 6 months exceeded a performance goal of 54% was 0.993, which exceeded the prespecified threshold of 0.977. Limb salvage (avoidance of above-ankle amputation) was attained in 67 patients (76.0% by Kaplan-Meier analysis). Wounds were completely healed in 16 of 63 patients (25%) and were in the process of healing in 32 of 63 patients (51%). No unanticipated device-related adverse events were reported.

CONCLUSIONS

We found that transcatheter arterialization of the deep veins was safe and could be performed successfully in patients with chronic limb-threatening ischemia and no conventional surgical or endovascular revascularization treatment options. (Funded by LimFlow; PROMISE II study ClinicalTrials.gov number, NCT03970538.).

National Treatment Patterns and Outcomes for Hospitalized Patients with Chronic Limb-Threatening Ischemia and End-Stage Kidney Disease

Background

Chronic limb-threatening ischemia (CLTI) can be associated with dismal outcomes but there are limited real-world data to further define the impact of end-stage kidney disease (ESKD) on outcomes nationally in this subset of patients. We sought to characterize national patterns of inpatient treatment of CLTI and compare outcomes in patients without ESKD.

Methods

The National Inpatient Sample was queried from 2015-2018 for all hospital admissions including treatment for CLTI. Mixed-effects linear and logistic regression models were used to estimate the effect of ESKD on outcomes and treatment choice.

Results

We identified 11 652 hospital admissions with CLTI alone and 2705 with CLTI + ESKD. Hospital admissions with CLTI + ESKD patients included patients who were younger (66 vs 69 years, P < .0001), less likely to be white (39% vs 63%, P < .0001), and more likely to reside in lower income large metropolitan areas. Admissions for CLTI + ESKD patients had a lower likelihood of open arterial reconstruction (OR .40, P < .0001) and a higher likelihood of endovascular revascularization or major limb amputation (OR 1.70, P < .0001). Admissions for CLTI + ESKD also had a 4.5- and 1.5-fold higher odds of in-hospital death and complications. These findings were associated with a longer LOS ( P < .0001), increased probability of discharge to rehabilitation facility (50% vs 41%, P < .0001), and greater hospital charges (median, $107 K vs $85 K, P < .0001).

Conclusions

Compared to hospital admissions for patients without ESKD, admissions for patients with CLTI + ESKD demonstrated distinctive demographic characteristics, a lower likelihood of open revascularization and a higher likelihood of endovascular revascularization and major limb amputation. Chronic limb-threatening ischemia + ESKD hospital admissions showed worse overall outcomes and greater resource utilization compared to CLTI admissions without ESKD.

The Impact of Chronic Kidney Disease on Mid-Term Outcomes after Revascularisation of Peripheral Arterial Occlusive Disease: Results from a Prospective Cohort Study

OBJECTIVE

The current study aimed to determine the relationship between chronic kidney disease (CKD) and major 12-month outcomes for patients with in-hospital treatment for symptomatic peripheral arterial occlusive disease (PAOD).

METHODS

An analysis of the prospective longitudinal multicentric cohort study with 12-month follow-up was conducted including patients who underwent endovascular or open surgery for symptomatic PAOD at 35 German vascular centres (initial study protocol: NCT03098290). Severity of CKD was grouped into four stages combining information about the estimated glomerular filtration rate (eGFR) at baseline and dialysis dependency. Outcomes included overall mortality as well as the two composite endpoints of amputation or death, and of major cardiovascular events (MACE). 12-month incidences and adjusted hazard ratios were estimated using the Kaplan-Meier function and Cox proportional hazard models.

RESULTS

A total of 4354 patients (32% female, 69 years mean age, 68% intermittent claudication, 69% percutaneous endovascular revascularisation) were included and followed for 244 days in median. Thereof, 22% had any CKD and 5% had end stage kidney disease (ESKD) at baseline. The 12-month overall mortality rate was 3.6% (95% CI 2.3-4.9) with 96 events in the entire cohort: 147 were amputated or died (5.3%, 95% CI 5.2-5.3), and 277 had a MACE (9.5%, 95% CI 9.4-9.5). When compared with patients without kidney disease, ESKD was significantly associated with overall mortality (HR 1.9; 95% CI 1.1-3.5), amputation or death (HR 2.4; 95% CI 1.4-4.1), and MACE (HR 2.0; 95% CI 1.3-3.2).

CONCLUSIONS

In the current study on mid-term outcomes after invasive revascularisation for symptomatic PAOD, one out of five patients suffered from any CKD while those few with ESKD had twice the odds of death, of amputation or death, and of major adverse cardiovascular events after twelve months. These results emphasise that concomitant CKD and its impact on outcomes should be considered by severity while mild and moderate grades should not lead to ineffectual treatment strategies.

ERICVA Risk Scale simplified as a predictor of amputation in critical limb ischemia

OBJECTIVE

Demonstrate that simplified ERICVA (Valladolid Critical Limb Ischaemia Risk Scale) is useful in predicting amputation in chronic limb-threatening ischemia (CLI) after one year of revascularization.

METHODS

A retrospective cohort study was performed. We analyzed the medical records of 93 patients over the age of 35 with the diagnosis of CLI who were treated in the Department of Internal Medicine, Orthopedics or in the Cardiovascular Surgery Unit of the Víctor Lazarte Echegaray Hospital and the High Complexity Virgen de La Puerta Hospital during the period 2015-2018. The simplified ERICVA score was determined in patients before surgical and endovascular revascularization. We included 31 patients who scored 2 or more points in the exposed group and 62 patients who scored less than 2 points in the group not exposed to amputation risk. The collected data was analyzed with the statistical program SPSS where the Relative Risk and significance was obtained with Pearson's Chi-square. The multivariate analysis was also carried out in order to obtain the adjusted relative risk.

RESULTS

It was identified that the simplified ERICVA score greater than or equal to 2 points was more frequent in those who underwent amputation (90.3%) compared to patients who did not undergo amputation (4.8%), increasing the risk of amputation in those patients with CLI who underwent revascularization (RR: 18.67, P<0.001). It was also possible to identify that within the group of patients that showed a high risk of amputation according to the ERICVA scale, they had a higher risk of major amputation (RR: 9.32, P<0.001) as opposed to the risk of minor amputation (RR: 1, 89, P=0.193). Among the items of the simplified ERICVA scale, the preoperative neutrophil-lymphocyte ratio and hematocrit were significantly higher in the group of amputated patients (P<0.001). In addition, it was possible to identify that the score greater than or equal to 2 was independently associated with the risk of amputation in patients revascularized with CLI (RR: 13.5, P<0.001).

CONCLUSION

In our patient population, the simplified ERICVA scale is useful in predicting major and minor amputation in critical limb ischemia after revascularization. The present data showed that the patients who had a simplified ERICVA score greater than or equal to 2 had a higher risk of major amputation compared to the risk of minor amputation. However, it is important to highlight that the impact on the prediction of minor amputation is greater because in some circumstances major amputation can appear as a complication of CLI.

Association of Chronic Kidney Disease with perioperative outcomes following acute lower limb revascularization

Background

There is a paucity of data examining the impact of advancing chronic kidney disease stages on outcomes following revascularization for acute limb ischemia. The present study examined the association of chronic kidney disease with in-hospital mortality, amputation, and resource utilization following revascularization for acute limb ischemia using a nationally representative cohort.

Methods

The 2016–2018 National Inpatient Sample was queried to identify all adult hospitalizations with lower extremity acute limb ischemia requiring surgical and/or endovascular interventions. Patients were grouped according to the presence of chronic kidney disease and its severity: no chronic kidney disease, chronic kidney disease 1–3 (chronic kidney disease stages 1 through 3), chronic kidney disease 4–5 (chronic kidney disease stages 4 through 5), and end-stage renal disease. Multivariable logistic and linear models were used to evaluate association of chronic kidney disease stage with outcomes of interest.

Results

Of an estimated 82,610 patients meeting study criteria, 14.8% had chronic kidney disease (chronic kidney disease 1–3: 63.4%, chronic kidney disease 4–5: 12.1%, end-stage renal disease: 24.5%). Compared to those with chronic kidney disease, chronic kidney disease patients were on average older, were more frequently female, and had a higher median Elixhauser Comorbidity Index. Increasing severity of chronic kidney disease was associated with a stepwise increase in unadjusted mortality rates (4.7% in no chronic kidney disease to 12.6% in end-stage renal disease, P < .001). Following risk adjustment, only end-stage renal disease was associated with increased odds of mortality (adjusted odds ratio 3.10, 95% confidence interval 2.28–4.22) and limb amputation (adjusted odds ratio 1.99, 95% confidence interval 1.59–2.48) compared to patients with no chronic kidney disease. Similarly, advancing chronic kidney disease stage conferred increased odds of prolonged length of stay and greater hospitalization costs.

Conclusion

Advanced renal dysfunction demonstrated inferior perioperative outcomes and greater health care expenditures in the study population. These findings imply that quality improvement efforts in acute limb ischemia revascularization should target patients with chronic kidney disease 4–5 and end-stage renal disease.

Long-Term Outcomes of Extra-Anatomic Femoro-Tibial Bypass Reconstructions in Chronic Limb-Threating Ischemia

(1) Background: While tibial bypass surgery still plays a role in the treatment of patients with chronic limb-threatening ischemia and diabetic foot syndrome; only a few centers have recorded considerable numbers of these conditions. The current study aimed to determine contemporary practice with special focus on the performance of extra-anatomic grafting to the infrapopliteal arteries. (2) Methods: A retrospective, single-center study included patients with tibial bypass grafts from 1 January 2008 to 31 December 2019. Primary endpoints were complication rate, graft patency, amputation, overall survival, and major adverse cardiac (MACE) or limb event (MALE). The cohort was stratified by extra-anatomic vs. anatomic position. (3) Results: A total of 455 patients (31% female) with Rutherford stage 4 (12.5%) and 5/6 (69.5%) were included (thereof, 19.5% had high amputation risk according to the Wound Ischemia Foot Infection score). Autologous reconstruction was performed in 316 cases, and prosthetic reconstruction in 131 cases, with a total of 51 (11.2%) extra-anatomic grafts. Early occlusion rate was 9.0% with an in-hospital overall mortality of 2.8%. The in-hospital rate of MACE was 2.4% and of MALE, 1.5%. After one, three and five years, the primary patency of venous bypasses was 74.5%, 68.6% and 61.7%, respectively. For prosthetic grafts, this was 55.1%, 46.0%, and 38.3%, respectively (p < 0.001). The patency of extra-anatomic prosthetic grafts performed significantly better compared with anatomically positioned prosthetic grafts (log-rank p = 0.008). In multivariate analyses, diabetes (hazard ratio, HR 1.314, CI 1.023−1.688, p = 0.032), coronary artery disease (HR 1.343, CI 1.041−1.732, p = 0.023), and dialysis dependency (HR 2.678, CI 1.687−4.250, p < 0.001) were associated with lower odds of survival (4) Conclusion: In this large, single-center cohort, tibial bypass surgery demonstrated satisfactory results with overall low perioperative complication rates and long-term patency rates of 60% and 38%, respectively. Extra-anatomic bypasses represent a feasible alternative to venous grafts in terms of patency. A tailored, patient-centered approach considering predictors such as diabetes, dialysis dependency, and coronary artery disease along with prediction models may further improve the long-term results in the future.

Rheopheresis for severe peripheral arterial disease in hemodialysis patients: A clinical series

BACKGROUND

Rheopheresis is a double-filtration plasmapheresis that removes high-molecular-weight molecules from the plasma and thereby lowers blood viscosity. This treatment has been proposed in hemodialysis (HD) patients for chronic limb-threatening ischemia (CLTI), but very few studies have evaluated the usefulness of this technique.

PRINCIPAL OBJECTIVE

To assess 1-year amputation-free survival (AFS) of HD patients suffering from CLTI treated by rheopheresis.

MATERIAL AND METHOD

We conducted a retrospective study of 28 consecutive HD patients treated by rheopheresis in three French dialysis centers between 1 February 2017 and 30 April 2019 in two indications resulting from CLTI, namely chronic ulceration or recent minor amputation with delayed healing.

RESULTS

One-year AFS rate reached 53.6 (-19.8; +16.3)%. One-year overall survival rate reached 67.9 (-20.5; +13.1)%. Main causes of death were infections and related to palliative care implying reduction or withdrawal of regular dialysis treatment. Hypotension episodes were the main rheopheresis adverse events with a prevalence rate of 13.5%. Rheopheresis sessions significantly reduced fibrinogen, C-reactive protein, α2-macroglobulin, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, IgM, and estimated plasma viscosity (P < .0001).

CONCLUSION

Rheopheresis may improve clinical outcomes of CLTI in HD patients. The assessment of rheopheresis effectiveness needs to be confirmed by a multicenter randomized controlled trial, such as the ongoing project in France (RHEO-PAD, NCT: 03975946).

Scoring Model to Predict Major Amputation in Patients With Chronic Limb-Threatening Ischemia at Wound, Ischemia, and Foot Infection Clinical Stage 4 After Endovascular Therapy

PURPOSE

We investigated the predictors of major amputation (MA) at 1 year and prepared a scoring model to stratify the clinical outcomes of chronic limb-threatening ischemia (CLTI) patients at wound, ischemia, and foot infection (WIfI) clinical stage 4 after endovascular therapy (EVT).

MATERIALS AND METHODS

This study was a retrospective, observational study performed at a single center. A total of 353 CLTI patients (390 limbs) were treated with EVT between April 2007 and December 2016. Among these, limbs at WIfI clinical stages 1, 2, and 3 were excluded, and 194 limbs at WIfI clinical stage 4 (49.7%) were enrolled. The primary endpoint was major amputation (MA) free rate at 1 year. Predictors of MA at 1 year was evaluated by Cox proportional hazard analysis.

RESULTS

At 1 year, the incidence of MA was 18.0% (35 limbs). Cox proportional hazard analysis revealed that hemodialysis (hazard ratio [HR] 2.63; 95% confidence interval [CI], 1.24-5.58; p=0.012), fI3 (HR 2.54; 95% CI, 1.28-5.06; p=0.008), toe wounds (HR 0.29; 95% CI, 0.094-0.88; p=0.029), and visible blood flow to the wound (HR 0.43; 95% CI, 0.21-0.89; p=0.023) were associated with MA. We assigned 1 point for positive predictors of MA, hemodialysis, and fI3; 1 point was deducted for negative predictors of MA, toe wounds, and visible blood flow to the wound. A score of -2 or -1, was defined as the low-risk group, 0 was defined as the intermediate-risk group, and +1 or +2 were defined as the high-risk group. At 1 year, MA free rate, wound healing rate, and amputation-free survival rate were stratified according to a scoring model. MA free rate was 96.6% in low-risk, 72.4% in intermediate-risk, and 67.3% in high-risk (p<0.001); wound healing rate was 67.8% in low-risk, 27.6% in intermediate-risk, and 4.1% in high-risk (p<0.001); amputation-free survival rate was 65.3% in low-risk, 44.8% in intermediate-risk, and 18.4% in high-risk (p<0.001).

CONCLUSIONS

The scoring model based on the predictors of MA stratified clinical outcomes in CLTI patients at WIfI clinical stage 4.

Efficacy of Fusion Imaging in Endovascular Revascularization of the Superficial Femoral Artery

BACKGROUND

The demand for endovascular revascularization (ER) to treat peripheral artery disease (PAD) has steadily increased. However, ER comes at the cost of increased contrast and radiation exposure, particularly in more complex cases. Fusion imaging is a new technology that may address these issues. The purpose of this study was to evaluate the efficacy of fusion imaging in ER of the superficial femoral artery (SFA).

METHODS

Patients with PAD undergoing ER of the SFA from February 2016 to July 2020 were retrospectively evaluated. A group of patients treated using fusion imaging was compared with a control group treated without fusion imaging. The primary end points were the contrast dose, fluoroscopy time, radiation dose, and operative time.

RESULTS

A total of 51 patients (fusion group, n = 26; control group, n = 25) underwent ER during the study period. Significantly lower iodinated contrast doses were observed in the fusion than in the control group (56.1 ± 23.7 vs. 87.9 ± 44.9 mL; P = 0.003), as well as significantly shorter fluoroscopy times (21.2 ± 11.1 vs. 44.9 ± 31.4 min; P = 0.001), lower radiation exposure (29.9 ± 8.9 vs. 122.2 ± 223.1 mGy; P = 0.04), and shorter operative times (88.3 ± 32.1 vs. 126.1 ± 66.8 min; P = 0.013).

CONCLUSIONS

The use of fusion imaging technology during ER of the SFA can significantly reduce the contrast dose, fluoroscopy time, radiation dose, and operative time.

Atherosclerotic Vascular Disease Associated with Chronic Kidney Disease

Cardiovascular risk increases as glomerular filtration rate (GFR) declines in progressive renal disease and is maximal in patients with end-stage renal disease requiring maintenance dialysis. Atherosclerotic vascular disease, for which hyperlipidemia is the main risk factor and lipid-lowering therapy is the key intervention, is common. However, the pattern of dyslipidemia changes with low GFR and the association with vascular events becomes less clear. While the pathophysiology and management of patients with early chronic kidney disease (CKD) is similar to the general population, advanced and end-stage CKD is characterized by a disproportionate increase in fatal events, ineffectiveness of statin therapy, and greatly increased risk associated with coronary interventions. The most effective strategies to reduce atherosclerotic cardiovascular disease in CKD are to slow the decline in renal function or to restore renal function by transplantation.

Early evaluation of the infrainguinal revascularization strategy selection tool of the Global Vascular Guidelines for chronic limb-threatening ischemia patients

OBJECTIVE

The Global Vascular Guidelines (GVG) propose a novel Global Anatomic Staging System (GLASS) with the Wound, Ischemia, and foot Infection (WIfI) classification system as a clinical decision-making tool for interventions in chronic limb-threatening ischemia (CLTI). We assessed the validity of clinical staging and the relationship between the treatments recommended by the GVG and the outcomes of the actual procedures.

METHODS

This retrospective, single-center, observational study included 117 patients with CLTI undergoing infrainguinal revascularization in our hospital between 2015 and 2019. Of those patients, 55 underwent open bypass (OB) and 62 underwent endovascular revascularization (EVR). Femoropopliteal, infrapopliteal, and inframalleolar GLASS grades were assigned based on angiographic images. These grades were combined to determine the revascularization strategy recommended by the GVG: "endovascular," "indeterminate," and "open bypass." The indeterminate category includes three subcategories: GLASS stage III, WIfI stage 2; GLASS stage II, WIfI stage 3; and GLASS stage II, WIfI stage 4. For the purposes of this study, we labeled these subcategories A, B, and C, respectively. The primary outcome was the correlation between the revascularization strategies recommended by the GVG and the actual procedures performed. The relationships between the actual procedures and overall survival, limb salvage, and patency were also examined.

RESULTS

The femoropopliteal and infrapopliteal GLASS grades were higher in the OB group. EVR was performed more often for GLASS stages I and II and was more often classified as indeterminate B and C, whereas OB was performed more often in GLASS stage III and was more often classified as indeterminate A. There were no statistically significant differences in the inframalleolar/pedal disease descriptor or in the 30-day postoperative complication rates between the two groups. In higher GLASS stages, the technical success rate of EVR was lower, and lesion complexity was more severe. Patients for whom the recommended strategy according to the GVG would have been OB but who underwent EVR were associated with low limb salvage and patency rates.

CONCLUSIONS

The GVG provide good guidance for the selection of the revascularization strategy. When the GVG indicate OB, it should be the treatment of choice, rather than EVR, for patients who are fit to undergo the procedure.

A prognostic risk score for major amputation in dialysis patients with chronic limb-threatening ischemia after endovascular revascularization

BACKGROUND

Almost 38% of all patients with end-stage chronic kidney disease (CKD) have peripheral arterial disease of the lower limbs that can lead to chronic limb threatening ischemia (CLTI). The aim of this study was to assess the impact of several factors to conduct a stratification of the amputation risk in CKD patients with CLTI receiving endovascular revascularization.

METHODS

Observational, retrospective, single-center study of patients treated from 2010 to 2016. The primary endpoint was the major amputation. The study included adult CKD dialysis patients affected by CLTI (rest pain and/or trophic lesions) with indication to endovascular revascularization and excluded for open repair.

RESULTS

A total of 82 patients were considered (58 men [70.7%], 24 women [29.3%] mean age 70.4±15.0 years). The number of major amputations was 28 (34.1%). The arterial lesion severity (TASC II-classification) and the trophic lesions extension (WIfI classification) were significantly associated with major amputation (OR and 95%CI, 1.20 [1.07-1.34], P=0.001; 2.65 [1.49-4.72], P=0.001; respectively). Based on the above-mentioned characteristics, a prognostic score was proposed to predict the major amputation risk. A score ≥23 was associated with a 67.6% probability of amputation in the following 12 months.

CONCLUSIONS

The CLTI revascularization is associated with poor outcomes in CKD patients. The present clinical score provided a pragmatic tool to calculate the major amputation risk. An elevated score could facilitate the decision-making process in order to perform an endovascular treatment vs. conservative approach.

Skeletal Muscle Mitochondrial Dysfunction and Oxidative Stress in Peripheral Arterial Disease: A Unifying Mechanism and Therapeutic Target

Peripheral artery disease (PAD) is caused by atherosclerosis in the lower extremities, which leads to a spectrum of life-altering symptomatology, including claudication, ischemic rest pain, and gangrene requiring limb amputation. Current treatments for PAD are focused primarily on re-establishing blood flow to the ischemic tissue, implying that blood flow is the decisive factor that determines whether or not the tissue survives. Unfortunately, failure rates of endovascular and revascularization procedures remain unacceptably high and numerous cell- and gene-based vascular therapies have failed to demonstrate efficacy in clinical trials. The low success of vascular-focused therapies implies that non-vascular tissues, such as skeletal muscle and oxidative stress, may substantially contribute to PAD pathobiology. Clues toward the importance of skeletal muscle in PAD pathobiology stem from clinical observations that muscle function is a strong predictor of mortality. Mitochondrial impairments in muscle have been documented in PAD patients, although its potential role in clinical pathology is incompletely understood. In this review, we discuss the underlying mechanisms causing mitochondrial dysfunction in ischemic skeletal muscle, including causal evidence in rodent studies, and highlight emerging mitochondrial-targeted therapies that have potential to improve PAD outcomes. Particularly, we will analyze literature data on reactive oxygen species production and potential counteracting endogenous and exogenous antioxidants.

Interplay of Diabetes Mellitus and End-Stage Renal Disease in Open Revascularization for Chronic Limb-Threatening Ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) confers a significant survival disadvantage and is associated with a high major amputation rate. Moreover, diabetes mellitus (DM) is an independent risk factor for developing CLTI. However, the interplay between end-stage renal disease (ESRD) and DM on outcomes after peripheral revascularization for CLTI is not well established. Our goal was to assess the effect of DM on outcomes after an infrainguinal bypass for CLTI in patients with ESRD.

METHODS

Using the Vascular Quality Initiative dataset from January 2003 to March 2020, records for all primary infrainguinal bypasses for CLTI in patients with ESRD were included for analysis. One-year and perioperative outcomes of all-cause mortality, reintervention, amputation-free survival (AFS), and major adverse limb event (MALE) were compared for patients with DM versus those without DM.

RESULTS

Of a total of 1,058 patients (66% male) with ESRD, 726 (69%) patients had DM, and 332 patients did not have DM. The DM group was younger (median age, 65 years vs. 68 years; P = 0.002), with higher proportions of obesity (body-mass index>30 kg/m2; 34% vs. 19%; P < 0.001) and current smokers (26% vs. 19%; P = 0.013). The DM group presented more frequently with tissue loss (76% vs. 66%; P < 0.001). A distal bypass anastomosis to tibial vessels was more frequently performed in the DM group compared to the non-DM group (57% vs. 45%; P < 0.001). DM was independently associated with higher perioperative MALE (OR 1.34; 95% CI, 1.06-1.68; P = 0.013), without increased risks of loss of primary patency and composite outcomes of amputation or death. On the mean follow-up of 11.4 ± 5.5 months, DM patients had a significantly higher rate of one-year MALEs (43% vs. 32%; P = 0.001). However, the one-year primary patency and AFS did not differ significantly. After adjusting for confounders, the risk-adjusted hazards for MALE (HR 1.34; 95% CI, 1.06-1.68; P = 0.013) were significantly increased in patients with DM. However, DM was not associated with increased risk of AFS (HR 1.16; 95% CI, 0.91-1.47; P = 0.238), or loss of primary patency (HR 1.04; 95% CI, 0.79-1.37; P = 0.767).

CONCLUSIONS

DM and ESRD each independently predict early and late major adverse limb events after an infrainguinal bypass in patients presenting with CLTI. However, in the presence of ESRD, DM may increase perioperative adverse events but does not influence primary patency and AFS at one year. The risk profile associated with ESRD appears to supersede that of DM, with no additive effect.

Systematic review and meta-analysis of outcomes of lower extremity peripheral arterial interventions in patients with and without chronic kidney disease or end-stage renal disease

OBJECTIVE

Patients with chronic kidney disease (CKD) have a greater risk of peripheral arterial disease (PAD). Although individual studies have documented an association between CKD and/or end-stage renal disease (ESRD) and adverse outcomes in patients undergoing PAD interventions in an era of technological advances in peripheral revascularization, the magnitude of the effect size is unknown. Therefore, we performed a meta-analysis to compare the outcomes of PAD interventions for patients with CKD/ESRD with those patients with normal renal function, stratified by intervention type (endovascular vs surgical), reflecting contemporary practice.

METHODS

Five databases were analyzed from January 2000 to June 2019 for studies that had compared the outcomes of lower extremity PAD interventions for patients with CKD/ESRD vs normal renal function. We included both endovascular and open interventions, with an indication of either claudication or critical limb ischemia. We analyzed the pooled odds ratios (ORs) across studies with 95% confidence intervals (CIs) using a random effects model. Funnel plot and exclusion sensitivity analyses were used for bias assessment.

RESULTS

Seventeen observational studies with 13,140 patients were included. All included studies, except for two, had accounted for unmeasured confounding using either multivariable regression analysis or case-control matching. The maximum follow-up period was 114 months (range, 0.5-114 months). The incidence of target lesion revascularization (TLR) was greater in those with CKD/ESRD than in those with normal renal function (OR, 1.68; 95% CI, 1.25-2.27; P = .001). The incidence of major amputations (OR, 1.97; 95% CI, 1.37-2.83; P < .001) and long-term mortality (OR, 2.28; 95% CI, 1.45-3.58; P < .001) was greater in those with CKD/ESRD. The greater TLR rates with CKD/ESRD vs normal renal function were only seen with endovascular interventions, with no differences for surgical interventions. The differences in rates of major amputations and long-term mortality between the CKD/ESRD and normal renal function groups were statistically significant, regardless of the intervention type.

CONCLUSIONS

Patients with CKD/ESRD who have undergone lower extremity PAD interventions had worse outcomes than those of patients with normal renal function. When stratifying our results by intervention (endovascular vs open surgery), greater rates of TLR for CKD/ESRD were only seen with endovascular and not with open surgical approaches. Major amputations and all-cause mortality were greater in the CKD/ESRD group, irrespective of the indication. Evidence-based strategies to manage this at-risk population who require PAD interventions are essential.

Peripheral Artery Disease in Vulnerable Patient Populations: Outcomes of Orbital Atherectomy in Native Americans Compared to Non-Native Americans. A Single-Center Experience in Rural Oklahoma

BACKGROUND/PURPOSE

Although the incidence of peripheral artery disease (PAD) and amputations is higher in Native Americans (NA) than Caucasians, the study of revascularization NA is limited, resulting in their under representation in clinical studies. Orbital atherectomy (OA) is widely utilized for endovascular revascularization of significantly calcified peripheral arteries and has been shown to improve limb salvage rates.

METHODS/MATERIALS

A cohort of 74 consecutive PAD subjects undergoing OA treatment was retrospectively analyzed via Kaplan Meier (KM) and Propensity Score Matched (PSM) analysis.

RESULTS

A significant proportion of the subjects were NA (16.2%). Compared to the non-NA, the NA had higher numerical baseline rates of wounds, dialysis, chronic kidney disease (CKD), and critical limb ischemia, but were numerically less likely to smoke and had similar rates of diabetes. There were very high rates of severe calcification (100% vs. 87%) and pre-procedure diameter stenosis (99% vs. 95%) in both groups. The NA and non-NA had good angiographic outcomes, resulting in low rates of post-procedure residual diameter stenosis (10% vs. 11%). Lastly, KM analysis indicated high freedom from amputation in both groups at 1 year (89% vs. 95%), as well as in the PSM subjects (89% vs. 100%).

CONCLUSIONS

Despite numerically higher rates of co-morbidities at baseline (e.g., CKD, dialysis, and presence of non-healing wounds), the NA underwent successful revascularization with OA, resulting in high freedom from amputation at 1-year. Given the small sample size of NA, these results may not be generalizable-thus, larger studies on NA are warranted.

Bypass Grafting vs Endovascular Therapy in Patients With Non-Dialysis-Dependent Chronic Kidney Disease and Chronic Limb-Threatening Ischemia (CRITISCH Registry)

Purpose: To report the outcomes of bypass grafting (BG) vs endovascular therapy (EVT) in patients with non-dialysis-dependent chronic kidney disease (CKD) and chronic limb-threatening ischemia (CLTI). Materials and Methods: The CRITISCH Registry is a prospective, national, interdisciplinary, multicenter registry evaluating the current practice of all available treatment options in 1200 consecutive CLTI patients. For the purposes of this analysis, only the 337 patients with non-dialysis-dependent CKD treated by either BG (n=86; median 78 years, 48 men) or EVT (n=251; median age 80 years, 135 men) were analyzed. The primary composite outcome was amputation-free survival (AFS); secondary outcomes were overall survival (OS) and amputation-free time (AFT). All outcomes were evaluated in Cox proportional hazards models; the results are reported as the hazard ratio (HR) and 95% confidence interval (CI). Results: The Cox regression analysis revealed a significantly greater hazard of amputation or death after BG (HR 1.78, 95% CI 1.05 to 3.03, p=0.028). The models for AFT and overall survival also suggested a higher hazard for BG, but the differences were not significant (AFT: HR 1.66, 95% CI 0.78 to 3.53, p=0.188; OS: HR 1.41, 95% CI 0.80 to 2.47, p=0.348). The absence of runoff vessels (HR 1.73, 95% CI 1.15 to 2.60, p=0.008) was associated with a decreased AFS. The likelihood of amputation was higher in male patients (HR 2.21, 95% CI 1.10 to 4.45, p=0.027) and was associated with a lack of runoff vessels (HR 1.95, 95% CI 0.96 to 3.95, p=0.065) and myocardial infarction (HR 3.74, 95% CI 1.23 to 11.35, p=0.020). Death was more likely in patients without runoff vessels (HR 1.76, 95% CI 1.11 to 2.80, p=0.016) and those with a higher risk score (HR 1.73, 95% CI 1.03 to 2.91, p=0.038). Conclusion: This analysis suggested that BG was associated with poorer AFS than EVT in patients with non-dialysis-dependent CKD and CLTI. Male sex, previous myocardial infarction, and the absence of runoff vessels were additionally identified as predictors of poorer outcomes.

Impact of Kidney Disease on Peripheral Arterial Interventions: A Systematic Review and Meta-Analysis

BACKGROUND

There are limited data on outcomes of patients undergoing peripheral arterial disease (PAD) interventions who have comorbid CKD/ESRD versus those who do not have such comorbid condition. We performed a systematic review and meta-analysis to analyze outcomes in this patient population.

METHODS

Five databases were searched for studies comparing outcomes of lower extremity PAD interventions for claudication and critical limb ischemia (CLI) in patients with CKD/ESRD versus non-CKD/non-ESRD from January 2000 to June 2019.

RESULTS

Our study included 16 observational studies with 44,138 patients. Mean follow-up was 48.9 ± 27.4 months. Major amputation was higher with CKD/ESRD compared with non-CKD/non-ESRD (odds ratio [OR 1.97] [95% confidence interval [CI] 1.39-2.80], p = 0.001). Higher major amputations with CKD/ESRD versus non-CKD/non-ESRD were only observed when indication for procedure was CLI (OR 2.27 [95% CI 1.53-3.36], p < 0.0001) but were similar for claudication (OR 1.15 [95% CI 0.53-2.49], p = 0.72). The risk of early mortality was high with CKD/ESRD patients undergoing PAD interventions compared with non-CKD/non-ESRD (OR 2.55 [95% CI 1.65-3.96], p < 0.0001), which when stratified based on indication, remained higher with CLI (OR 3.14 [95% CI 1.80-5.48], p < 0.0001) but was similar with claudication (OR 1.83 [95% CI 0.90-3.72], p = 0.1). Funnel plot of included studies showed moderate bias.

CONCLUSIONS

Patients undergoing lower extremity PAD interventions for CLI who also have comorbid CKD/ESRD have an increased risk of experiencing major amputations and early mortality. Randomized trials to understand outcomes of PAD interventions in this at-risk population are essential.

Influence of end-stage renal disease on long-term survival after major amputation

Background: To analyze long-term outcomes and possible influencing factors in patients with endstage renal disease (ESRD) and critical limb ischemia (CLI) after major amputation compared to patients with normal renal function and non-dialysis-dependent chronic kidney disease. Patients and methods: Abstraction of single-center medical records of patients undergoing above knee (AKA) and below knee (BKA) amputation over a 10 years period (n = 436; 2009-2018). Excluded were amputations due to trauma or tumor. Patients were subdivided according to renal function in three categories: ESRD patients (n = 98), non-dialysis dependent chronic kidney disease (CKD, n = 98) and normal renal function (NF, n = 240). Predefined endpoints were survival and postoperative complications. Cox-regression models were built to analyze independent risk factors for outcome parameters. Results: In total, 298 AKA, 133 BKA and 5 knee joint exarticulations were performed. ESRD patients showed inferior in-hospital results as to death (ESRD 36.7 % vs. CKD 19.4 % and NF 20.0 %, P = .002). Similarly, long-term survival rates (6 months: ESRD 55.0 % vs. CKD 69.4 %, NF 67.9 % 1 year: ESRD 48.6 %, CKD 60.2 %, NF 60.8 % 5 years: ESRD 9.9 %, CKD 31.8 %, NF 37.1 %, P < .001) were significantly decreased for ESRD patients. Median postoperative survival was 10 months in ERSD, and 22 months in CKD and NF, respectively. Analysis of postoperative surgical complications revealed no differences between groups (ESRD 19.4 %, CKD 17.3 %, NF 17.0 %; P = 0.433). Cox regression analysis indicated that dialysis (HR 1.63; 95 % CI 1.22-2.16; P = .001), hypertension (HR 1.59; 95 % CI 0.99-2.54) and smoking (HR 1.22; 95 % CI 1.03-1.44; P = .022) was associated with increased risk of death during follow-up. Conclusions: Mortality after limb amputation in ERSD patients remains high. Survival of ERSD patients is lower in relation to chronic kidney disease and patients with normal renal function. Due to poor in hospital outcomes and absent long-term survival, benefit of primary amputation in ERSD seems scarce.

Outcomes of severe limb ischemia with tissue loss and impact of revascularization in haemodialysis patients with wound, ischemia, and foot infection (WIfI) stage 3 or 4

Summary. Background: With growing prevalence, end-stage renal disease (ESRD) as well as critical limb ischemia (CLI) are both conditions associated with high morbidity and mortality rates. Patients and methods: A retrospective single-centre study provided data of a German interdisciplinary vascular centre. Seventy-seven consecutive haemodialysis (HD) inpatients (median age, 73.6 years) with 91 threatened limbs with Wound, Ischemia, and foot Infection (WIfI) clinical stage 3 or 4 were evaluated for in-hospital treatment of peripheral arterial disease, limb salvage rates, major amputation (MA)-free and overall survival. Results: The 1-year MA-free limb salvage rate was 82 %. On multivariate analysis, a higher WIfI clinical stage (hazard ratio [HR], 7.54; p = 0.008) indicated a higher risk of MA, while at least one-vessel run-off to the foot after revascularization of any kind was associated with a lower risk of MA (HR, 0.17; p = 0.001). In the composite endpoint analysis, the 1-year MA-free overall survival rate was 65 %. Patients with limbs in WIfI clinical stage 4 versus stage 3 carried a more than two-fold increased hazard of death or MA (HR, 2.63; p = 0.028), while revascularization was associated with reduced risk (HR, 0.40; p = 0.021). One-year overall survival (78 %) was not associated with WIfI stage or revascularization but was worse in patients with previous symptomatic coronary artery disease (HR, 3.25; p = 0.039). During long-term follow-up over 12 years, MA-free survival probability was significantly lower in the WIfI stage 4 versus WIfI stage 3 group (HR, 1.58; p = 0.048) without significant differences in overall survival (HR, 1.10; p = 0.696). Conclusions: Lower-extremity CLI with tissue loss in HD patients is associated with high morbidity and mortality rates. WIfI clinical stage was predictive of 1-year MA-free survival, while revascularization significantly reduced MA risk but did not influence overall survival.

Comparison of open and endovascular procedures in patients with critical limb ischemia on dialysis

OBJECTIVE

Peripheral artery disease is a common comorbidity in patients with end-stage renal disease (ESRD), but there is a paucity of data comparing outcomes of different interventions in this group of patients. In this study, we examined perioperative outcomes of lower extremity endovascular revascularization (ER) and open revascularization (OR) in dialysis patients with critical limb ischemia (CLI).

METHODS

Patients on dialysis and undergoing ER and OR for CLI from 2011 to 2015 were identified in the American College of Surgeons National Surgical Quality Improvement Program dataset. Patient demographics, comorbidities, anatomic features, and perioperative outcomes were compared between ER and OR procedures.

RESULTS

From 2011 to 2015, 1021 lower extremity revascularizations were performed in dialysis patients with CLI. In this group, 535 were ER (53%) and 486 were OR (47%) procedures. Although demographic characteristics such as age and gender were similar between the two groups, there was a higher proportion of Caucasians and African Americans in the OR group. Patients undergoing open and endovascular procedures had similar rates of hypertension, congestive heart failure, diabetes, chronic obstructive pulmonary disease, and bleeding disorders. A minority of procedures (4%) were emergencies, which were distributed equally between the two groups. Preoperative aspirin usage was higher in the ER group (84% vs 78%; P = .024), beta-blocker use was higher in the OR group (79% vs 74%; P = .08), and statin use was similar between the two groups (72% in OR and 70% in ER; P = .54). On risk-adjusted multivariate analysis, OR was associated with a lower rate of major amputation (5.97% vs 11.78%; odds ratio, 0.48; 95% confidence interval [CI], 0.26-0.85), but a higher rate of postoperative bleeding (29.6% vs 8.97%; odds ratio, 2.86; 95% CI, 1.8-4.35) and wound complications (15% vs 3%; odds ratio, 4.5; 95% CI, 2.38-8.3). The 30-day mortality and cardiovascular morbidity were similar between the two groups.

CONCLUSIONS

In patients with ESRD with CLI, OR is associated with a lower risk of major limb amputation but a higher rate of postoperative wound complications and bleeding, compared with ER. Cardiovascular complications, 30-day mortality, reinterventions and readmissions were similar between the two groups. In patients with ESRD with CLI, OR should be considered as an option for limb salvage if feasible. Long-term outcomes comparing the two types of procedures are needed.