CKD and Acute and Long-Term Outcome of Patients with Peripheral Artery Disease and Critical Limb Ischemia

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.

Comparison of mortality and amputation after lower extremity bypass versus peripheral vascular intervention in patients with chronic limb-threatening ischemia and comorbid chronic kidney disease

OBJECTIVE

Comorbid chronic kidney disease (CKD) is associated with worse outcomes for patients with chronic limb-threatening ischemia (CLTI). However, comparative effectiveness data are limited for lower extremity bypass (LEB) vs peripheral vascular intervention (PVI) in patients with CLTI and CKD. We aimed to evaluate (1) 30-day all-cause mortality and amputation and (2) 5-year all-cause mortality and amputation for LEB vs PVI in patients with comorbid CKD.

METHODS

Individuals who underwent LEB and PVI were queried from the Vascular Quality Initiative with Medicare claims-linked outcomes data. Propensity scores were calculated using 13 variables, and a 1:1 matching method was used. The mortality risk at 30 days and 5 years in LEB vs PVI by CKD was assessed using Kaplan-Meier and Cox proportional hazards models, with interaction terms added for CKD. For amputation, cumulative incidence functions and Fine-Gray models were used to account for the competing risk of death, with interaction terms for CKD added.

RESULTS

Of 4084 patients (2042 per group), the mean age was 71.0 ± 10.8 years, and 69.0% were male. Irrespective of CKD status, 30-day mortality (hazard ratio [HR]: 0.94, 95% confidence interval [CI]: 0.63-1.42, P = .78) was similar for LEB vs PVI, but LEB was associated with a lower risk of 30-day amputation (sub-HR [sHR]: 0.66, 95% CI: 0.44-0.97, P = .04). CKD status, however, did not modify these results. Similarly, LEB vs PVI was associated with a lower risk of 5-year mortality (HR: 0.79, 95% CI: 0.71-0.88, P < .001) but no difference in 5-year amputation (sHR: 1.03, 95% CI: 0.89-1.20, P = .67). CKD status did not modify these results.

CONCLUSIONS

Regardless of CKD status, patients had a lower risk of 5-year all-cause mortality and 30-day amputation with LEB vs PVI. Results may help inform preference-sensitive treatment decisions on LEB vs PVI for patients with CLTI and CKD, who may commonly be deemed too high risk for surgery.

Impact of Chronic Kidney Disease on In-Hospital Outcomes of Hospitalizations With Acute Limb Ischemia Undergoing Endovascular Therapy

PURPOSE

Studies on outcomes related to endovascular treatment (EVT) in advanced stages of chronic kidney disease (CKD) and end-stage renal disease (ESRD) among hospitalizations with acute limb ischemia (ALI) are limited.

METHODS

The Nationwide Inpatient Sample was quarried from October 2015 to December 2017 to identify the hospitalizations with ALI and undergoing EVT. The study population was subdivided into 3 groups based on their CKD stages: group 1 (No CKD, stage I, stage II), group 2 (CKD stage III, stage IV), and group 3 (CKD stage V and ESRD). The primary outcome was all-cause in-hospital mortality.

RESULTS

A total of 51 995 hospitalizations with ALI undergoing EVT were identified. The in-hospital mortality was significantly higher in group 2 (OR = 1.17; 95% CI 1.04 - 1.32, p=0.009) and group 3 (OR = 3.18; 95% CI 2.74-3.69, p<0.0001) compared with group 1. Odds of minor amputation, vascular complication, atherectomy, and blood transfusion were higher among groups 2 and 3 compared with group 1. Group 2 had higher odds of access site hemorrhage compared with groups 1 and 3, whereas group 3 had higher odds of major amputation, postprocedural infection, and postoperative hemorrhage compared with groups 1 and 2. Besides, groups 2 and 3 had lower odds of discharge to home compared with group 1. Finally, the length of hospital stay and cost of care was significantly higher with the advancing CKD stages.

CONCLUSION

Advanced CKD stages and ESRD are associated with higher mortality, worse in-hospital outcomes and higher resource utilization among ALI hospitalizations undergoing EVT.

CLINICAL IMPACT

Current guidelines are not clear for the optimum first line treatment of acute limb ischemia, especially in patients with advanced kidney disease as compared to normal/mild kidney disease patients. We found that advanced kidney disease is a significant risk factor for worse in-hospital morbidity and mortality. Furthermore, patients with acute limb ischemia and advanced kidney disease is associated with significantly higher resource utilization as compared to patients with normal/mild kidney disease. This study suggests shared decision making between treating physician and patients when considering endovascular therapy for the treatment of acute limb ischemia in patients with advanced kidney disease.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Outcomes of peripheral artery disease and polyvascular disease in patients with end-stage kidney disease

OBJECTIVE

Patients with peripheral artery disease (PAD) and end-stage kidney disease are a high-risk population, and concomitant atherosclerosis in coronary arteries (CAD) or cerebral arteries (CVD) is common. The aim of the study was to assess long-term outcomes of PAD and the impact of coexistent CAD and CVD on outcomes.

METHODS

The United States Renal Data System was used to identify patients with PAD within 6 months of incident dialysis. Four groups were formed: PAD alone, PAD with CAD, PAD with CVD, and PAD with CAD and CVD. PAD-specific outcomes (chronic limb-threatening ischemia, major amputation, percutaneous/surgical revascularization, and their composite, defined as major adverse limb events [MALE]) as well as all-cause mortality, myocardial infarction, and stroke were studied.

RESULTS

The study included 106,567 patients (mean age, 71.2 years; 40.8% female) with a median follow-up of 546 days (interquartile range, 214-1096 days). Most patients had PAD and CAD (49.8%), 25.8% had PAD alone, and 19.2% had all three territories involved. MALE rate in patients with PAD was 22.3% and 35.0% at 1 and 3 years, respectively. In comparison to PAD alone, the coexistence of both CAD and CVD (ie, polyvascular disease) was associated with a higher adjusted rates of all-cause mortality (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.24-1.31), myocardial infarction (HR, 1.78; 95% CI, 1.69-1.88), stroke (HR, 1.66; 95% CI, 1.52,1.80), and MALE (HR, 1.07; 95% CI, 1.04-1.11).

CONCLUSIONS

Patients with end-stage kidney disease have a high burden of PAD with poor long-term outcomes, which worsen, in an incremental fashion, with the involvement of each additional diseased arterial bed.

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.

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.

Corrected QT Interval and Outcomes of Dialysis Patients with Symptomatic Peripheral Artery Disease: A Prospective Cohort Study

BACKGROUND

Peripheral artery disease (PAD) is common and associated with a higher risk of cardiovascular morbidity and mortality in dialysis patients. A longer corrected QT (QTc) interval has been associated with adverse cardiovascular events and mortality in the general population and patients with end-stage kidney disease. However, little evidence is available on the predictive value of QTc in dialysis patients with PAD.

METHODS

We conducted a prospective cohort study of 356 dialysis patients with symptomatic PAD undergoing endovascular therapy. We performed the resting 12-lead electrocardiogram (ECG) at baseline. Cox regression analyses were used to assess the association of QTc with all-cause mortality and major adverse cardiovascular events (MACEs), defined as non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death.

RESULTS

The mean age was 67.3 ± 11.5 years; 41.6% of participants were women. The median QTc was 471 (interquartile ranges 448-491) milliseconds (ms). During a median follow-up of 2.2 years, 188 (52.8%) patients died, and MACEs occurred in 119 (33.4%) patients. In multivariable-adjusted models, patients in tertile 3 of QTc levels had a significantly greater risk of all-cause mortality (hazard ratio [HR] 2.41, 95% confidence intervals [CI] 1.58-3.69) and MACEs (HR 1.90, 95% CI 1.15-3.13) than those in tertile 1. Similarly, each 10-ms increase in the baseline QTc predicted a higher risk of all-cause death (HR 1.15, 95% CI 1.09-1.21) and MACEs (HR 1.15, 95% CI 1.07-1.23).

CONCLUSIONS

QTc prolongation was independently associated with adverse outcomes among dialysis patients with symptomatic PAD.

Analysis of Lower Extremity Amputations from the SerbVasc Registry

BACKGROUND

Peripheral arterial disease (PAD) and diabetes are the major causes of lower extremity amputations (LEAs) worldwide. Morbidity and mortality in patients with LEAs are high with an associated significant burden on the global health system. The aim of this article is to report the overall morbidity and mortality rates after major and minor LEAs from the Serbian Vascular Registry (SerbVasc), with an analysis of predictive factors that influenced adverse outcomes.

MATERIALS AND METHODS

SerbVasc was created in 2019 as a part of the Vascunet collaboration that is aiming to include all vascular procedures from 21 hospitals in Serbia. Prevalence of diabetes among patients with LEAs, previous revascularization procedures, the degree and the type of foot infection and tissue loss, and overall morbidity and mortality rates were analyzed, with a special reference to mortality predictors.

RESULTS

In the period from January 2020 to December 2022, data on 702 patients with LEAs were extracted from the SerbVasc registry, mean age of 69.06±10.63 years. Major LEAs were performed in 59%, while minor LEAs in 41% of patients. Diabetes was seen in 65.1% of the patients, with 44% of them being on insulin therapy. Before LEA, only 20.3% of patients had previous peripheral revascularization. Soft tissue infection, irreversible acute ischemia, and Fontaine III and IV grade ischemia were the most common causes of above-the-knee amputations while diabetic foot was the most common cause of transphalangeal and toe amputations. The infection rate was 3.7%, the re-amputation rate was 5.7%, and the overall mortality rate was 6.9%, with intrahospital mortality in patients with above-the-knee amputation of 11.1%. The most significant intrahospital mortality predictors were age >65 years (p<0.001), chronic kidney disease (CKD) (p<0.001), ischemic heart disease (IHD) (p=0.001), previous myocardial revascularization (p=0.017), emergency type of admission (p<0.001), not using aspirin (p=0.041), using previous anticoagulation therapy (p=0.003), and postoperative complications (p<0.001).

CONCLUSIONS

The main predictors of increased mortality after LEAs from the SerbVasc registry are age >65 years, CKD, IHD, previous myocardial revascularization, emergency type of admission, not using aspirin, using previous anticoagulation therapy, and postoperative complications. Taking into account high mortality rates after LEAs and a small proportion of previous peripheral revascularization, the work should be done on early diagnosis and timely treatment of PAD hopefully leading to decreased number of LEAs and overall mortality.

CLINICAL IMPACT

Mortality after lower limb amputation from the SerbVasc register is high. A small number of previously revascularized patients is of particular clinical importance, bearing in mind that the main reasons for above-the-knee amputations were irreversible ischemia, Fontaine III and Fontaine IV grade ischemia. Lack of diagnostics procedures and late recognition of patients with PAD, led to subsequent threating limb ischemia and increased amputation rates. The work should be done on early diagnosis and timely treatment of PAD in Serbia, hopefully leading to an increased number of PAD procedures, decreased number of LEAs, and lower overall mortality.

Risk Factors for Lower Extremity Amputation in Patients with End-Stage Kidney Disease: A Nationwide Cohort Study

Individuals with end-stage kidney disease (ESKD) on dialysis are at a high risk of developing foot ulcerations and undergoing subsequent lower extremity amputation (LEA), which can exert significant impacts on their quality of life and contribute to rising healthcare costs. We aimed to identify risk factors associated with LEA in patients with ESKD to predict LEA progression and eventually prevent it. We used 18 years (2002-2019) of data from the Korean National Health Insurance Service (KNHIS). Data were collected from patients with ESKD who underwent renal replacement therapy (RRT) and had no history of amputation caused by trauma or toxins. The risk factors were compared between patients with or without LEA. We collected data from 220,838 patients newly diagnosed with ESKD, including 6348 in the LEA group and 214,490 in the non-LEA group. The total incidence of LEA was 2.9%. Older age, male gender, lower income, non-metropolitan residence, diabetes mellitus, dialysis treatment (compared to kidney transplantation), microvascular disease, peripheral vascular disease, endovascular procedure, and endovascular operation were associated with an increased risk of LEA. Thus, individuals with ESKD who are at a higher risk for LEA should be closely monitored, and kidney transplantation should be considered as a preventative measure.

Acute Kidney Injury Following Revascularization in Patients With Chronic Limb-Threatening Ischemia and Non-Dialysis-Dependent Chronic Kidney Disease: Insights From the NSQIP Database at 30-Day Follow-Up

BACKGROUND

Patients with chronic limb-threatening ischemia (CLTI) and chronic kidney disease (CKD) are at risk of developing renal injury following revascularization. We aimed to compare the risk of adverse renal events following endovascular revascularization (ER) or open surgery (OS) in patients with CLTI and CKD.

METHODS

A retrospective analysis of the National Surgical Quality Improvement Program (NSQIP) databases (2011-2017) was performed including patients with CLTI and non-dialysis-dependent CKD, comparing ER to OS. The primary outcome was a composite of postprocedural kidney injury or failure within 30 days. Thirty-day mortality, major adverse cardiac and cerebrovascular events (MACCE), amputation, readmission or target lesion revascularization (TLR) were compared using multivariate logistic regression and propensity-score matched analysis.

RESULTS

A total of 5009 patients were included (ER: 2361; OS: 3409). The risk for the composite primary outcome was comparable between groups (odds ratio [OR]: 0.78, 95% confidence interval (CI): 0.53-1.17) as for kidney injury (n=54, OR: 0.97, 95% CI: 0.39-1.19) or failure (n=55, OR: 0.68, 95% CI: 0.39-1.19). In the adjusted regression, a significant benefit was observed with ER for the primary outcome (OR: 0.60, p=0.018) and renal failure (OR: 0.50, p=0.025), but not for renal injury (OR: 0.76, p=0.34). Lower rates of MACCE, TLR, and readmissions were observed after ER. Thirty-day mortality and major amputation rates did not differ. In the propensity score analysis, revascularization strategy was not associated with renal injury or failure.

CONCLUSIONS

In this cohort, the incidence of renal events within 30 days of revascularization in CLTI was low and comparable between ER and OR.

CLINICAL IMPACT

In a cohort of 5009 patients with chronic limb-threatening ischemia and non-end-stage chronic kidney disease (CKD), postprocedural kidney injury or failure within 30 days was comparable between patients submitted to open or endovascular revascularization (ER). Lower rates of major adverse cardiac and cerebrovascular events, target lesion revascularization, and readmissions were observed after endovascular revascularization. Based on these findings, ER should not be avoided due to fear of worsening renal function in CKD patients with chronic limb-threatening ischemia. In fact, these patients benefit more from ER regarding cardiovascular outcomes with no increased risk of kidney injury.

Contemporary in-hospital and long-term prognosis of patients with acute ST-elevation myocardial infarction depending on renal function: a retrospective analysis

BACKGROUND

Cardiovascular disease is often associated with chronic kidney disease (CKD), resulting in an increased risk for poor outcome. We sought to determine short-term mortality and overall survival in ST-elevation myocardial infarction (STEMI) patients with different stages of CKD.

METHODS

In our retrospective cohort study with health insurance claims data of the Allgemeine Ortskrankenkasse (AOK), anonymized data of all STEMI patients hospitalized between 2010 and 2017 were analyzed regarding presence and severity of concomitant CKD.

RESULTS

A total of 175,187 patients had an index-hospitalisation for STEMI (without CKD: 78.6% patients, CKD stage 1: 0.8%, CKD stage 2: 4.8%, CKD stage 3: 11.7%, CKD stage 4: 2.8%, CKD stage 5: 0.7%, CKD stage 5d: 0.6%). Patients with CKD were older and had more co-morbidities than patients without CKD. With increasing CKD severity, patients received less revascularization therapies (91.2%, 85.9%, 87.0%, 81.8%, 71.7%, 76.9% and 78.6% respectively, p < 0.001). After 1 year, guideline-recommended medications were prescribed less frequently in advanced CKD (83.4%, 79.3%, 81.5%, 74.7%, 65.0%, 59.4% and 53.7%, respectively, p < 0.001). CKD stages 4, 5 and 5d as well as chronic limb threatening ischemia (CLTI) were associated with decreased overall survival [CKD stage 4: hazard ratio (HR) 1.72; 95% CI 1.66-1.78; CKD stage 5: HR 2.55; 95% CI 2.37-2.73; CKD stage 5d: 5.64; 95% CI 5.42-5.86; CLTI: 2.06; 95% CI 1.98-2.13; all p < 0.001].

CONCLUSIONS

CKD is a frequent co-morbidity in patients with STEMI and is associated with a worse prognosis especially in advanced stages. Guideline-recommended therapies in patients with STEMI and CKD are still underused.

Role of triglyceride glucose index in long-term mortality of patients with lower extremity arterial disease

Aim: This work was designed to explore the role of the triglyceride-glucose (TyG) index in the prediction of long-term mortality in patients with lower extremity artery disease (LEAD) undergoing endovascular revascularization. Methods: The records of 723 patients with symptomatic LEAD undergoing endovascular revascularization between January 2016 and December 2021, with long-term follow-up until December 2021, were analyzed. Results: The rate of long-term mortality was significantly higher among patients with high TyG index than patients with low TyG index. Conclusion: The TyG index is an independent predictor of long-term mortality in patients with LEAD undergoing endovascular revascularization.

One year clinical outcomes of Rutherford 6 chronic limb threatening ischemia patients undergoing lower limb endovascular revascularisation from Singapore

Background

Percutaneous transluminal angioplasty (PTA) is widely used as a first-line revascularisation option in patients with chronic limb threatening ischemia (CLTI). This study aimed to evaluate the short-term endovascular revascularisation treatment outcomes of a cohort of Rutherford 6 (R6) CLTI patients, from a multi-ethnic Asian population in Singapore.

Patients with R6 CLTI who underwent endovascular revascularisation from June 2019 to February 2020 at Singapore General Hospital, a tertiary vascular centre in Singapore, were included and followed up for one year. Primary outcome measures included number and type of reinterventions required, 3-, 6- and 12-month mortality, 6- and 12-month amputation free survival (AFS), wound healing success and changes in Rutherford staging after 3, 6 and 12 months.

Results

Two hundred fifty-five procedures were performed on 86 patients, of whom 78 (90.7%) were diabetics, 54 (62.8%) had coronary artery disease (CAD) and 54 (62.8%) had chronic kidney disease (CKD). 42 patients (48.8%) required reintervention within 6 months. Multivariate analysis revealed that the presence of CAD was a significant independent predictor for reintervention. Mortality was 15.1%, 20.9% and 33.7% at 3, 6 and 12 months respectively. AFS was 64.0% and 49.4% at 6 and 12 months. Inability to ambulate, congestive heart failure (CHF), dysrhythmia and CKD were significant independent predictors of lower 12-month AFS.

Conclusions

PTA for R6 CLTI patients was associated with relatively high mortality and reintervention rates at one year. CAD was an independent predictor of reintervention. More research is required to help risk stratify which CLTI patients would benefit from an endovascular-first approach versus conservative treatment or an immediate major lower extremity amputation policy.

Effect of Comorbidities on Outcomes of Infrapopliteal Angioplasty in Patients with Chronic Limb-Threatening Ischemia

OBJECTIVE

This subgroup analysis aimed to evaluate the effect of comorbidities on infrapopliteal angioplasty outcomes in patients with chronic limb-threatening ischemia (CLTI).

METHODS

This was an observational study evaluating eligible CLTI patients aged >18 years who underwent infrapopliteal angioplasty between April 2014 and May 2017 at a tertiary care center. Subgroup analyses were based on (1) baseline glycated hemoglobin (HbA1c ≤6.5% vs >6.5%), (2) presence/absence of chronic kidney disease (CKD), and (3) control of lipid parameters.

RESULTS

A total of 231 patients with 332 infrapopliteal vessels were treated. While diabetes was prevalent in all participants, hypertension, coronary artery disease, and CKD were reported in 76.6%, 46.3%, and 25.5% of patients at baseline, respectively. The overall technical success rate was 84.4%, and the patency rate at 6 months was 82.04%. Patency at 6 months, wound healing, in-line flow, and complete plantar arch formation were numerically higher in patients with HbA1c ≤6.5% versus >6.5%, but all comparisons were nonsignificant. According to multivariable analysis, the odds of wounds not healing was 2.38 times higher (odds ratio [OR] = 2.4, 95% confidence interval [CI]: 1.2 to 4.5) and developing plantar arch was 5.88 times higher (OR = 5.9, 95% CI: 1.3 to 25) among patients with CKD compared with patients without CKD.

CONCLUSIONS

The 6-month outcomes of infrapopliteal angioplasty may be better in patients with controlled versus uncontrolled glycemic levels. Control of lipid parameters may not have a significant influence on outcomes, especially in patients on statin therapy. The short-term outcomes may be similar in patients with and without CKD.

Machine Learning Approach to Predict In-Hospital Mortality in Patients Admitted for Peripheral Artery Disease in the United States

Background Peripheral artery disease (PAD) affects >10 million people in the United States. PAD is associated with poor outcomes, including premature death. Machine learning (ML) has been increasingly used on big data to predict clinical outcomes. This study aims to develop ML models to predict in-hospital mortality in patients hospitalized for PAD based on a national database. Methods and Results Inpatient hospitalization data were obtained from the 2016 to 2019 National Inpatient Sample. A total of 150 921 inpatients were identified with a primary diagnosis of PAD and PAD-related procedures using codes of the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) and International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS). Four ML models, including logistic regression, random forest, light gradient boosting, and extreme gradient boosting models, were trained to predict the risk of in-hospital death based on a selection of variables, including patient characteristics, comorbidities, procedures, and hospital-related factors. In-hospital mortality occurred in 1.8% of patients. The performance of the 4 models was comparable, with the area under the receiver operating characteristic curve ranging from 0.83 to 0.85, sensitivity of 77% to 82%, and specificity of 72% to 75%. These results suggest adequate predictability for clinical decision-making. In all 4 models, the total number of diagnoses and procedures, age, endovascular revascularization procedure, congestive heart failure, diabetes, and diabetes with complications were critical predictors of in-hospital mortality. Conclusions This study demonstrates the feasibility of ML in predicting in-hospital mortality in patients with a primary PAD diagnosis. Findings highlight the potential of ML models in identifying high-risk patients for poor outcomes and guiding personalized intervention.

Rejuvenated endothelial progenitor cells through overexpression of cellular prion protein effectively salvaged the critical limb ischemia in rats with preexisting chronic kidney disease

BACKGROUND

This study tested the hypothesis that overexpression of cellular prion protein in endothelial progenitor cells (PrPc^OE-EPCs), defined as "rejuvenated EPCs," was superior to EPCs for salvaging the critical limb ischemia (CLI) induced after 28-day chronic kidney disease (CKD) induction in rat.

METHODS AND RESULTS

Cell viability and flow cytometric analyses of early/late apoptosis/total-intracellular ROS/cell cycle (sub-G1, G2/M phase) were significantly higher in EPCs + H₂O₂ than in EPCs that were significantly reversed in PrPc^OE-EPCs + H₂O₂ (all p < 0.001). The protein expressions of inflammation (IL-1ß/IL-6/MMP-9/p-NF-κB) were significantly increased in EPC + TNF-α than in EPCs that were significantly reversed in PrPc^OE-EPCs + TNF-α (all p < 0.001). Adult-male SD rats (n = 8/each group) were categorized into group 1 (sham-operated control), group 2 (CKD + CLI), group 3 [CKD + CLI + EPCs by intravenous (0.6 × 10⁵)/intra-muscular (0.6 × 10⁵) injections at 3 h after CLI induction], group 4 (CKD + CLI + PrPc^OE-EPCs/dose-administration as group 3) and group 5 (CKD + CLI + siPrnp-EPCs/dose-administration as group 3). By day 14 after CLI induction, the ratio of ischemia to normal blood flow (INBF) in CLI area was highest in group 1/lowest in group 2/significantly higher in group 4 than in groups 3/5 and significantly higher in group 3 than in group 5 (all p < 0.0001). Histopathology demonstrated that the angiogenesis (number of small vessels/CD31 + cells) exhibited a similar trend, whereas the fibrosis/kidney injury score exhibited an opposite pattern of INBF among the groups (all p < 0.0001). The protein expressions of angiogenesis (SDF-1α/VEGF/CXCR4)/cell-stress signaling (p-PI3K/p-Akt/p-m-TOR) were significantly and progressively increased from groups 1-4 that were reversed in group 5 (all p < 0.0001). The protein expressions of fibrotic (p-Smad3/TGF-ß)/oxidative-stress (NOX-1/NOX-2/oxidized-protein)/apoptotic (mitochondrial-Bax/cleaved caspase3/cleaved PARP)/mitochondrial-damaged (cytosolic-cytochrome-C) biomarkers displayed an opposite pattern of INBF among the groups (all p < 0.0001).

CONCLUSION

PrPc^OE-EPCs were superior to EPCs only therapy for salvaging the CLI.

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.

Malnutrition is Associated with Increased Morbidity and Mortality in Dialysis Patients Undergoing Endovascular Therapy for Peripheral Artery Disease

OBJECTIVES

Revascularization for peripheral artery disease (PAD) is increasingly common in dialysis patients. Patients with PAD who have undergone revascularization are at high risk for subsequent complications. Malnutrition is an important modifiable risk factor for dialysis patients, yet little data exist on the prognostic impact of malnutrition on postprocedure long-term outcomes.

METHODS

A total of 395 consecutive dialysis patients undergoing endovascular revascularization for PAD between 2005 and 2019 were examined for the primary outcome of all-cause mortality. Secondary outcomes included major adverse limb events (MALEs), defined as acute limb ischemia, major amputation, and clinically driven revascularization, and major adverse cardiovascular events (MACEs). Nutritional status was assessed by using the Controlling Nutritional Status (CONUT) score, a screening tool for malnutrition incorporating albumin, cholesterol, and total lymphocyte count.

RESULTS

According to the CONUT score, 40.8% of patients were moderately or severely malnourished. During a median follow-up of 2.2 years, 218 (55.2%) patients died; 211 (53.4%) patients had MALEs, and MACEs occurred in 135 (34.2%) patients. Compared with normal nutritional status, severe malnutrition was associated with a significantly increased risk for all-cause death (adjusted HR, 4.83; 95% CI, 2.56-9.12) and MALEs (adjusted HR, 2.42; 95% CI, 1.23-4.74) but not MACEs (adjusted HR, 1.81; 95% CI, 0.74-4.40). Similar results were observed when the CONUT score was analyzed as a continuous variable.

CONCLUSIONS

Malnutrition is common among dialysis patients with PAD requiring endovascular therapy and is strongly associated with increased mortality and MALEs. Clinical trials are needed to evaluate whether nutritional interventions improve outcomes for dialysis patients after peripheral revascularization.

Single Versus Multiple Arterial Revascularization in Patients With Reduced Renal Function: Long-term Outcome Comparisons in 23,406 CABG Patients From Ontario, Canada

OBJECTIVE

To compare the long-term outcomes of MAR versus SAR in patients with renal insufficiency.

SUMMARY OF BACKGROUND DATA

Previous studies have been insufficiently powered to address whether MAR confers long-term benefit over SAR in patients with renal dysfunction who require CABG.

METHODS

We conducted retrospective cohort study in Ontario, Canada of patients who underwent isolated CABG (n = 23,406). The primary outcome was MACE, defined as the composite of stroke, myocardial infarction, and repeat revascularization. We compared patients by matching them on the propensity to have received SAR versus MAR, within groups with preoperative glomerular filtration rate (GFR) ≥60 mL/min/1.73 m2; GFR between 30 and 60; and GFR <30.

RESULTS

In patients with GFR ≥60, the use of MAR versus SAR was associated with a lower rate of MACE [hazard ratio (HR) 0.87 (0.80-0.94)], and a lower rate of long-term mortality [HR 0.87 (0.79-0.97)]. In those with GFR between 30 and 60, MAR was not associated with a difference in MACE [HR 1.04 (0.87-1.26)], and a lower rate of long-term mortality [HR 0.75 (0.65-0.87)] was observed. In those with GFR <30, MAR was not associated with a difference in outcomes.

CONCLUSIONS

MAR versus SAR does not correlate with a difference in MACE amongst patients with GFR between 30 and 60 and better survival raises the possibility of indication bias. Furthermore, MAR did not confer a benefit in those with severely reduced renal function. These data suggest that the potential long-term benefits of using MAR in CABG patients with renal insufficiency may be offset by competing health risks.

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).

Accuracy of Ankle-Brachial Index, Toe-Brachial Index, and Risk Classification Score in Discriminating Peripheral Artery Disease in Patients With Chronic Kidney Disease

The accuracy of ankle-brachial index (ABI) and toe-brachial index (TBI) in discriminating lower extremity peripheral artery disease (PAD) has not been evaluated in patients with chronic kidney disease (CKD). We measured ABI, TBI, and Doppler ultrasound in 100 predialysis patients with CKD without revascularization or amputation. Leg-specific ABI was calculated using higher systolic blood pressure (SBP) in posterior tibial or dorsalis pedis artery divided by higher brachial SBP; alternative ABI was calculated using lower SBP in posterior tibial or dorsalis pedis artery. PAD was defined as ≥50% stenosis detected by Doppler ultrasound. PAD risk classification score was calculated using cardiovascular disease risk factors. The area under the curve (AUC, 95% confidence interval [CI]) for discriminating ultrasound-diagnosed PAD was 0.78 (0.69 to 0.87) by ABI, 0.80 (0.71 to 0.89) by alternative ABI, and 0.74 (0.63 to 0.86) by TBI. Sensitivity and specificity were 25% and 97% for ABI ≤0.9, 41% and 95% for alternative ABI ≤0.9, and 45% and 93% for TBI ≤0.7, respectively. AUC (95% CI) of PAD risk classification score was 0.86 (0.78 to 0.94) with sensitivity and specificity of 95% and 60% for risk score ≥0.10, 76% and 76% for risk score ≥0.25, and 43% and 95% for risk score ≥0.55. Combining risk score with ABI, alternative ABI, and TBI increased AUC (95% CI) to 0.89 (0.82 to 0.96), 0.89 (0.80 to 0.98), and 0.87 (0.78 to 0.96), respectively. In conclusion, current ABI and TBI diagnostic criteria have high specificity but low sensitivity for classifying PAD in patients with CKD. PAD classification risk score based on cardiovascular disease risk factors improves the accuracy of PAD classification.

Expression of Vascular Cell Adhesion Molecule-1 in Peripheral Artery Disease is Enriched in Patients with Advanced Kidney Disease

BACKGROUND

Serving as an inflammatory biomarker in patients under regular hemodialysis (HD), the arterial tissue expression of vascular cell adhesion molecule 1 (VCAM-1) in patients with different renal function has rarely been investigated and remains unclear.

METHODS

Fifty-one consecutive patients with peripheral arterial disease (PAD) who underwent percutaneous transluminal angioplasty were recruited and divided into a normal renal function group, chronic kidney disease (CKD) group, and HD group. Background disease, clinical and angiographic severity, and serum level of VCAM-1 in the three groups were analyzed. The tissue expression of VCAM-1 was quantitatively demonstrated by immunohistochemical (IHC) staining and protein extraction from cell membranes in another amputated cohort.

RESULTS

In PAD patients, the serum level of VCAM-1 was significantly elevated in the HD group compared with the other two groups (1990.2 ± 607.1 ng/ml vs. 1547.9 ± 511.2 ng/ml vs. 1161.0 ± 435.8 ng/ml, p < 0.001). Serum VCAM-1 was a prognostic factor of major adverse cardiac or limb events (odds ratio: 1.002, 95% confidence interval: 1.001-1.003, p = 0.003). The expression of VCAM-1 was higher in the PAD amputated arterial tissue of CKD and HD patients as demonstrated by quantitative analysis of IHC staining and quantitative membrane protein extraction.

CONCLUSIONS

VCAM-1 is a cardiovascular prognostic biomarker. Both serum level and the tissue expression of VCAM-1 were significantly higher in PAD patients with advanced kidney disease.

Impact of high on-treatment platelet reactivity after angioplasty in patients with critical limb ischemia

OBJECTIVES

Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is standard of care in patients with peripheral artery disease (PAD) after percutaneous transluminal angioplasty (PTA). However, high on treatment platelet reactivity (HTPR) to DAPT is frequent and associated with major adverse limb events (MALE) in PAD patients. Nevertheless, association of MALE and HTPR in patients with critical limb ischemia (CLI) is not known. Moreover, comorbidities might confound response to antiplatelet medication further. Hence, in this trial we analyzed pharmacodynamic responses to DAPT and clinical events in CLI patients post PTA.

METHODS

In this prospective single center pilot analysis, we included 71 CLI patients. Patients received DAPT after PTA. Antiplatelet effect were measured by light transmission aggregometry (LTA) and vasodilator-stimulated protein phosphorylation assay (VASP). MALE, major adverse cardiac and cerebrovascular events (MACCE) and BARC bleeding within 12 months follow-up were assessed.

RESULTS

Mean age of patients was 73.37 ± 7.36 years and 47 (66.2%) were male. Overall HTPR appeared in 46 patients (64.8%). MALE and MACCE showed no differences between patients with and patients without HTPR. However, bleeding was higher in patients with sufficient pharmacodynamic response to DAPT (Bleeding - HTPR: 13.4% vs. no HTPR: 36.0%; log-rank HR: 0.32; 95% CI 0.1079 to 0.9396 p = 0.0217). This finding remained robust in multivariate analysis.

CONCLUSION

HTPR to DAPT is frequent in CLI patients. However, bleeding was higher in patients with sufficient response to DAPT. Ischemic events did not differ. Hence, CLI patients might benefit from an alternative antithrombotic approach.

Impact of chronic kidney disease on the outcomes of infrapopliteal venous, and heparin-bonded expanded polytetrafluoroethylene bypass surgeries: A retrospective cohort study

The aim of this study was to analyze the results of infrapopliteal venous and prosthetic bypass surgeries for patients with chronic limb-threatening ischemia (CLTI) and moderate to severe chronic kidney disease (CKD). All consecutive patients undergoing infrapopliteal bypass surgeries at two academic vascular centers between March 2002 and November 2018 were included in this retrospective study. During this timeframe, infrapopliteal grafts were performed for 487 patients. Of these patients, 160 (32.9%; group 1) had normal renal function, 248 (50.9%; group 2) had moderate CKD, and 79 (16.2%; group 3) had severe CKD according to the Kidney Disease Improving Global Outcomes guidelines. After 5 years' follow-up, the primary patency rate was 46.0% and the secondary patency rate was 54.9% without statistical significance noted between the CKD groups. Limb salvage (65.3%, p = 0.024) and long-term survival (19.6%, p < 0.001) were considerably lower in patients with severe CKD. In subgroup analysis, vein grafts had significantly better long-term patency rates compared to prosthetic grafts, regardless of CKD group. However, in patients with severe CKD, patency rates of vein and heparin-bonded expanded polytetrafluoroethylene (HePTFE) grafts were comparable at the 1-year mark. Our study shows that autologous vein grafts remain the first choice for infrapopliteal bypass surgeries in patients with CKD. HePTFE grafts showed good short-term results in patients with severe CKD. Given the short life expectancy of these high-risk patients, prosthetic HePTFE grafts may be reasonable in this population if a suitable vein is absent.

The Impact of Chronic Kidney Disease on Peripheral Artery Disease and Peripheral Revascularization

Chronic kidney disease (CKD) is a clinical condition characterized by high morbidity and mortality. Globally, CKD is also increasing in prevalence and incidence. The two principal kidney measures namely estimated glomerular filtration rate (eGFR) and albuminuria have been found to be predictors of renal and cardiovascular (CV) endpoints including peripheral artery disease (PAD). The prevalence of PAD was increased in CKD patients and, particularly, in patients with more severe CKD stages. Despite the fact that revascularization strategies are suitable in CKD patients in similar fashion to non-CKD patients, few CKD patients underwent these procedures. In fact, if it is true that revascularization improves prognosis in PAD patients irrespective of baseline eGFR, it was also demonstrated that CKD patients, who underwent revascularization, were at higher risk for amputations, mortality, re-intervention and perioperative complications. With the present review article, we have examined the association between CKD, PAD and peripheral revascularization highlighting data about epidemiology, pathophysiologic mechanisms, and results from previous observational and intervention studies. We have also examined the future perspectives and challenges of research around the association between CKD and PAD.

Central and peripheral arterial diseases in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Chronic kidney disease (CKD) affects about 10% of all populations worldwide, with about 2 million people requiring dialysis. Although patients with CKD are at high risk of cardiovascular disease and events, they are often underrepresented or excluded in clinical trials, leading to important knowledge gaps about how to treat these patients. KDIGO (Kidney Disease: Improving Global Outcomes) convened the fourth clinical Controversies Conference on the heart, kidney and vasculature in Dublin, Ireland, in February 2020, entitled Central and Peripheral Arterial Diseases in Chronic Kidney Disease. A global panel of multidisciplinary experts from the fields of nephrology, cardiology, neurology, surgery, radiology, vascular biology, epidemiology, and health economics attended. The objective was to identify key issues related to the optimal detection, management, and treatment of cerebrovascular diseases, central aortic disease, renovascular disease, and peripheral artery disease in the setting of CKD. This report outlines the common pathophysiology of these vascular processes in the setting of CKD, describes best practices for their diagnosis and management, summarizes areas of uncertainty, addresses ongoing controversial issues, and proposes a research agenda to address key gaps in knowledge that, when addressed, could improve patient care and outcomes.

SNF472: mechanism of action and results from clinical trials

PURPOSE OF REVIEW

Vascular calcification (VC) is associated with increased cardiovascular event rates, particularly in patients with end-stage kidney disease (ESKD). Dysregulated mineral metabolism and inflammation have been shown to promote VC, however, treatment options targeting VC specifically are not available. This review outlines the pathophysiological mechanisms contributing to VC in ESKD and describes recent studies evaluating the effects of the first-in-class inhibitor of VC, SNF472.

RECENT FINDINGS

SNF472 directly inhibits calcium phosphate crystal formation and aggregation. SNF472 has completed early phase clinical trials with a favourable safety profile and Phase 2 clinical trial data have shown attenuation of coronary artery and aortic valve calcification in patients receiving hemodialysis.

SUMMARY

Therapeutic agents that directly target VC may prevent the multiple complications associated with dystrophic calcification in patients with ESKD.

Comparison of Pre-Amputation Evaluation in Patients with and without Chronic Kidney Disease

INTRODUCTION

Patients with chronic kidney disease (CKD) and peripheral artery disease (PAD) are more likely to undergo lower extremity amputation than patients with preserved kidney function. We sought to determine whether patients with CKD were less likely to receive pre-amputation care in the 1-year prior to lower extremity amputation compared to patients without CKD.

METHODS

We conducted a retrospective observational study of patients with PAD-related lower extremity amputation between January 2014 and December 2017 using a large commercial insurance database. The primary exposure was CKD identified using billing codes and laboratory values. The primary outcomes were receipt of pre-amputation care, defined as diagnostic evaluation (ankle-brachial index, duplex ultrasound, and computed tomographic angiography), specialty care (vascular surgery, cardiology, orthopedic surgery, and podiatry), and lower extremity revascularization in the 1-year prior to amputation. We conducted separate logistic regression models to estimate the adjusted odds ratio (aOR) and 95% confidence intervals (CIs) among patients with and without CKD. We assessed for effect modification by age, sex, Black race, and diabetes status.

RESULTS

We identified 8,554 patients with PAD-related amputation. In fully adjusted models, patients with CKD were more likely to receive diagnostic evaluation (aOR 1.30; 95% CI 1.17-1.44) and specialty care (aOR 1.45, 95% CI 1.27-1.64) in the 1-year prior to amputation. There was no difference in odds of revascularization by CKD status (aOR 1.03, 0.90-1.19). Age, sex, Black race, and diabetes status did not modify these associations.

DISCUSSION/CONCLUSION

Patients with CKD had higher odds of receiving diagnostic testing and specialty care and similar odds of lower extremity revascularization in the 1-year prior to amputation than patients without CKD. Disparities in access to pre-amputation care do not appear to explain the higher amputation rates seen among patients with CKD.

Safety and outcomes of combined carbon dioxide angiography and OCT-guided femoro-popliteal chronic total occlusion crossing and directional atherectomy in patients with chronic kidney disease

BACKGROUND

Carbon dioxide angiography with addition of optical coherence tomography imaging may improve procedural success and clinical outcomes in patients with peripheral artery disease and chronic kidney disease.

METHODS

Single-center, retrospective analysis of patients with chronic kidney disease who underwent carbon dioxide angiography and optical coherence tomography-guided chronic total occlusion crossing and/or optical coherence tomography-guided directional atherectomy was performed. Patient and procedure-related characteristics, along with peri- and one-year post-procedural major adverse events, were analyzed.

RESULTS

A total of 18 vessels in 11 patients, with mean age 70 years were treated. All had co-morbidities such as hypertension, hyperlipidemia, had history or were current smokers with baseline peripheral artery disease. Majority were diabetic with coronary disease (82%); 55% baseline chronic kidney disease IV, 55% Rutherford class III and 45% class IV. Contrast was used in only two patients. Mean total fluoroscopy time and radiation dose was 24.1 min and 249.2 mGY, respectively. Half of the lesions were femoro-popliteal chronic total occlusions, and Ocelot catheter was used to cross seven of nine chronic total occlusions and was successful in six. Adjunctive optical coherence tomography-guided directional atherectomy was performed in 8 of 11 patients. Only two adverse events occurred: one clinically significant event of slow-flow intra-procedurally and one target limb revascularization within one year of index procedure in a vessel different than prior treated. Optical coherence tomography imaging in both chronic total occlusion-crossing and atherectomy resulted in 10-min mean fluoroscopy reduction time and 32 mGY reduction in radiation dose.

CONCLUSION

Carbon dioxide angiography with the addition of optical coherence tomography imaging for chronic total occlusion crossing and/or optical coherence tomography-guided directional atherectomy reduced the need for contrast agents, total fluoroscopy time, and radiation exposure in patients with peripheral artery disease and baseline chronic kidney disease.

The association of estimated glomerular filtration rate with outcomes following infrainguinal bypass for peripheral arterial disease

OBJECTIVE

Chronic kidney disease (CKD) is a recognized predictor of long-term survival, frequently coexisting with peripheral arterial disease (PAD). Estimated glomerular filtration rate (eGFR) is a more accurate marker of renal function than creatinine. This study sought to determine the graded impact of CKD, defined by eGFR, on infrainguinal lower extremity bypass (LEB) outcomes.

METHODS

This retrospective study examined 44,332 patients from the Vascular Quality Initiative database who underwent LEB between January 2003 and November 2019. The GFR was estimated using the Modification of Diet in Renal Disease equation. Multivariable logistic regression was used to study perioperative mortality and Kaplan-Meier survival estimation and multivariable Cox regression were used to evaluate 5-year mortality, 1-year major amputation, and major amputation/death.

RESULTS

The 30-day mortality odds was increased for CKD 3 (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.32-1.91; P < .001) and CKD 5 (OR, 3.08; 95% CI, 2.45-3.87; P < .001) relative to CKD 1 to 2. Comparing CKD stages 3, 4, and 5 with CKD 1 and 2, there was a stepwise increase in the adjusted hazard of 5-year mortality (hazard ratio [HR], 1.18; 95% CI, 1.09-1.27; P < .001), (HR, 1.73; 95% CI; 1.47-2.03; P < .001) and (HR, 2.58; 95% CI, 2.33-3.84; P < .001), respectively. Although the risk of 1-year death or major amputation did not differ for CKD 3 compared with CKD 1, this was 50% higher for CKD 4 (HR, 1.50; 95% CI, 1.26-1.78; P < .001) and doubled for CKD 5 (HR, 2.07; 95% CI, 1.87-2.29; P < .001) compared with CKD 1 and 2. The adjusted HR for major amputation in 1 year was 0.81 (95% CI, 0.71-0.92; P = .002), 1.14 (95% CI, 0.84-1.54; P = .396) and 1.56 (95% CI,1.31-1.84; P < .001) for CKD 3, 4, and 5, respectively, compared with CKD 1 and 2.

CONCLUSIONS

The estimated GFR is a useful predictor of postoperative mortality, overall survival, and/or amputation after LEB in patients with PAD. It should be considered in the preoperative risk-benefit analysis process to guide patient selection in the population with concomitant PAD and CKD being considered for LEB.

Outcomes of Lower Extremity Endovascular Revascularization: Potential Predictors and Prevention Strategies

Peripheral artery disease (PAD) is a manifestation of atherosclerosis, which may affect arteries of the lower extremities. The most dangerous PAD complication is chronic limb-threatening ischemia (CLTI). Without revascularization, CLTI often causes limb loss. However, neither open surgical revascularization nor endovascular treatment (EVT) ensure long-term success and freedom from restenosis and revascularization failure. In recent years, EVT has gained growing acceptance among all vascular specialties, becoming the primary approach of revascularization in patients with CLTI. In clinical practice, different clinical outcomes after EVT in patients with similar comorbidities undergoing the same procedure (in terms of revascularization technique and localization of the disease) cause unsolved issues that need to be addressed. Nowadays, risk management of revascularization failure is one of the major challenges in the vascular field. The aim of this literature review is to identify potential predictors for lower extremity endovascular revascularization outcomes and possible prevention strategies.

Feasibility and impact of carbon dioxide angiography on acute kidney injury following endovascular interventions in patients with peripheral artery disease and renal impairment

BACKGROUND

Post-contrast acute kidney injury (AKI) is a dreaded complication of endovascular revascularization using iodinated contrast medium in patients with peripheral artery disease and concomitant chronic kidney disease (CKD). This study sought to evaluate the incidence of AKI in patients with peripheral artery disease and CKD undergoing endovascular revascularization and using carbon dioxide (CO₂) as contrast medium.

METHODS AND RESULTS

From 04/2015 to 07/2018, all consecutive peripheral artery disease patients with CKD stage ≥ 3 referred for endovascular revascularization of symptomatic peripheral artery disease were prospectively included. During endovascular revascularization, CO₂ as contrast medium was manually injected and iodinated contrast medium was additionally used when needed. The reference group consisted of 211 cardiovascular risk factor-matched patients undergoing endovascular revascularization with iodinated contrast medium only. CO₂-guided endovascular revascularization was performed in 102 patients, thereof 16 (15.7%) patients exclusively with CO₂. Baseline CKD stage ≥ 4 and iodinated contrast medium volume > 50 ml were disproportionally associated with post-procedural post-contrast AKI. At CKD stage 4 the odds ratio for post-contrast AKI was 13.2 (95% CI 1.489-117.004; p = 0.02) for iodinated contrast medium volume 51-100 ml and 37.7 (95% CI 3.927-362.234; p = 0.002) for iodinated contrast medium volume > 100 ml. The corresponding values at CKD stage 5 were 23.7 (95% CI 2.666-210.583; p = 0.005) and 28.3 (95% CI 3.289-243.252; p = 0.002), respectively. Radiation (dose area product) was significantly higher in the CO₂-endovascular revascularization group (6.025 ± 6.926 cGy*cm² vs. 4.281 ± 4.722 cGy*cm², p = 0.009).

CONCLUSION

CO₂ is an applicable and safe alternative to iodinated contrast medium for endovascular revascularization in peripheral artery disease patients with concomitant CKD. Patients with CKD stage 4 or 5, being at highest risk for post-contrast AKI, should primarily be treated by CO₂-guided endovascular revascularization.

AgeR deletion decreases soluble fms-like tyrosine kinase 1 production and improves post-ischemic angiogenesis in uremic mice

Peripheral arterial disease occurs more frequently and has a worse prognosis in patients with chronic kidney disease (CKD). The receptor for advanced glycation end products (RAGE) is involved in multiple aspects of uremia-associated vasculopathy. Previous data suggest that the RAGE pathway may promote soluble fms-like tyrosine kinase 1 (sFlt1) production, an anti-angiogenic molecule. Thus, we tested the hypothesis that the deletion of AgeR would decrease sFlt1 production and improve post-ischemic revascularization in uremic condition. We used a well-established CKD model (5/6 nephrectomy) in WT and AgeR-/- C57/Bl6 mice. Hindlimb ischemia was induced by femoral artery ligation. Revascularization was evaluated by complementary approaches: ischemic limb retraction, LASCA imagery, and capillary density. The production of sFlt1 was assessed at both RNA and protein levels. After hindlimb ischemia, uremic mice showed slower functional recovery (p < 0.01), decreased reperfusion (p < 0.01), lower capillary density (p = 0.02), and increased circulating sFlt1 levels (p = 0.03). AgeR deletion restored post-ischemic angiogenesis and was protective from sFlt1 increase in uremic mice. These findings show the main role of RAGE in post-ischemic angiogenesis impairment associated with CKD. RAGE may represent a key target for building new therapeutic approaches to improve the outcome of CKD patients with PAD.

Temporal trends and outcomes of critical limb ischemia among patients with chronic kidney disease

There is a paucity of data on the outcomes and revascularization strategies for critical limb ischemia (CLI) among patients with chronic kidney disease (CKD). Hence, we conducted a nationwide analysis to evaluate the trends and outcomes of hospitalizations for CLI with CKD. The National Inpatient Sample database (2002-2015) was queried for hospitalizations for CLI. The trends of hospitalizations for CLI with CKD were reported, and endovascular versus surgical revascularization strategies for CLI with CKD were compared. The main study outcome was in-hospital mortality. The analysis included 2,139,640 hospitalizations for CLI, of which 484,224 (22.6%) had CKD. There was an increase in hospitalizations for CLI with CKD (P_trend = 0.01), but a reduction in hospitalizations for CLI without CKD (P_trend = 0.01). Patients with CLI and CKD were less likely to undergo revascularization compared with patients without CKD. CLI with CKD had higher rates of in-hospital mortality (4.8% vs 2.5%, adjusted odds ratio (OR) 2.01; 95% CI 1.93-2.11) and major amputation compared with no CKD. Revascularization for CLI with CKD was associated with lower rates of mortality (3.7% vs 5.3%, adjusted-OR 0.78; 95% CI 0.72-0.84) and major amputation compared with no revascularization. Compared with endovascular revascularization, surgical revascularization for CLI with CKD was associated with higher rates of in-hospital mortality (4.7% vs 2.7%, adjusted-OR 1.67; 95% CI 1.43-1.94). In conclusion, this contemporary observational analysis showed an increase in hospitalizations for CLI among patients with CKD. CLI with CKD was associated with higher in-hospital mortality compared with no CKD. Compared with endovascular therapy, surgical revascularization for CLI with CKD was associated with higher in-hospital mortality.

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.

Carbon Dioxide As a Standard of Care for Zero Contrast Interventions: When, Why and How?

BACKGROUND

Traditional contrast media containing iodine remain the gold standard for vessel visualization during endovascular procedures. On the other hand, their use has several side effects and implications and may cause contrast medium-induced nephropathy. Carbon dioxide (CO2) angiography is an old alternative technique used only for critical patients in order to prevent kidney damages or allergic reactions. Zero contrast procedure: The availability of automated CO2 injectors has led to an increase in the use of CO2 angiography, providing an option for zero contrast interventions, preserving patient renal function and saving costs for the hospital facility. Taking advantage of the properties of CO2 gas, it is possible to improve the performance of some complex procedures such as atherectomy and the detection of type II endoleaks after EVARs. However, a learning curve is needed to get good imaging, and learn about the qualities and limitations of the technique.

CONCLUSIONS

The use of automatic delivery systems for CO2 angiography appears to be a good choice for the use of CO2 as the first imaging option. The standardization of injection protocols and the extensive use of this technique could lead to significant benefits both for the patient's prospects and health facilities.

Implications of Renal Disease in Patients Undergoing Peripheral Arterial Interventions

Since the first peripheral endovascular intervention (PVI) in 1964, the procedure's technical aspects and indications have advanced significantly. Today, endovascular procedures span the spectrum of presentations from acute limb ischemia to critical limb ischemia and symptomatic limiting claudication. Goals of PVI remain restoring limb perfusion, minimizing rates of amputation and mortality, and sparing the need for the high-risk bypass surgery. Unfortunately, there are no large randomized controlled trials that address the optimal approach to peripheral arterial disease revascularization in chronic kidney disease (CKD) patients.

Impact of high on-treatment platelet reactivity after angioplasty in patients with peripheral arterial disease

Objective: High on-treatment platelet reactivity (HTPR) to dual antiplatelet therapy (DAPT) predicts adverse events in coronary artery disease patients. In peripheral artery disease (PAD) patients, data concerning the clinical impact of HTPR are limited. Therefore, we evaluated the incidence of (i) HTPR to DAPT and (ii) its impact on 6 months outcome after angioplasty.Methods and results: In this prospective single center analysis, we investigated 102 consecutive patients with PAD from 2016 to 2017. All patients underwent peripheral endovascular treatment due to intermittent claudication (Fontaine IIb). Clopidogrel effects were measured using vasodilator-stimulated protein phosphorylation (VASP) assay, aspirin effects by light-transmission aggregometry (LTA). Major adverse limb events (MALE), major adverse cardiac and cerebrovascular events (MACCE) and BARC bleeding (bleeding academic research consortium classification) within 6 months were assessed. HTPR to clopidogrel (n = 37, 36%), to aspirin (n = 11, 11%) and to both (n = 11, 11%) were frequent. Compared to sufficient platelet inhibition by aspirin and clopidogrel (n = 43, 42%), patients with dual HTPR showed a higher risk of MALE at 6 months (27% vs. 7%; hazard ratio [HR]: 4.45; 95% confidence interval [CI]: 1.1 to 67.8; p = .03). This was independent of diabetes, creatinine, body mass index, and age as well as of procedural details in a multivariate logistic regression analysis. MACCE (n = 2) and BARC bleeding rates (n = 2) were low.Conclusion: In this small exploratory study, HTPR was frequent in PAD patients. Furthermore, the results are suggestive that MALE might be associated with dual HTPR. This leads to the hypothesis that optimized antithrombotic regimens post percutaneous transluminal angioplasty should be tested in clinical trials.

Mortality and chronic obstructive pulmonary disease in patients treated with endovascular revascularization of the infra-inguinal lower limb arteries from retrograde access

Background

In this trial, our objective was to evaluate the relationship between long-term clinical outcomes in patients with peripheral arterial disease (PAD) treated with retrograde endovascular recanalization (ER) of chronic total occlusions (CTOs) regarding the infra-inguinal lower limb arteries and chronic obstructive pulmonary disease (COPD).

Methods

A total of 834 consecutive subjects were enrolled in the study. The mean age was 67.8±10.6 years (62.6% males). COPD was diagnosed in 98 patients (11.7%). The infra-inguinal location included the deep, superficial and common femoral artery, popliteal artery or below the knee arteries. During follow-up, we evaluated major adverse cardiac and cerebrovascular events (MACCE) and major adverse limb events (MALE). MACCE was considered as death, stroke/transient ischemic attack, myocardial infarction, percutaneous coronary intervention or coronary artery bypass grafting operation, while MALE regarded amputation, target lesion re-intervention, target vessel re-intervention and surgical action.

Results

The mean follow-up was 1,144.9±664.3 days and the interquartile range was 1,110.5 (504.5–1,734.7). Data were collected between 2006 and 2016. We noticed significant differences in death rates among the COPD and non-COPD groups. The cumulative number of events (deaths) was 12.2%, 17.3%, 18.4%, 22.4%, 23.5%, 23.5% and 23.5% in the COPD group and 6.1%, 7.5%, 10.5%, 11.3%, 11.4% 11.5% and 11.5% in the non-COPD group after 1, 2, 3, 4, 5, 6 and 7 years of follow-up, and was notably greater for COPD (P=0.0007).

Conclusions

Patients with COPD and PAD treated with the ER and retrograde approach due to CTOs are related to higher mortality than non-COPD patients.

Chronic kidney disease and outcomes of lower extremity revascularization for peripheral artery disease

BACKGROUND & AIMS

Renal disease is a risk factor for peripheral artery disease (PAD), yet its impact on outcomes after lower extremity (LE) revascularization is not well established. We aimed to characterize the association between chronic kidney disease (CKD) and/or end stage renal disease (ESRD) and post-procedural outcomes in PAD patients undergoing LE revascularization in the United States.

METHODS

Adults age ≥18 years undergoing surgical or endovascular LE revascularization for PAD with and without CKD or ESRD were identified from the 2014 Nationwide Readmissions Database. Major adverse cardiovascular events (MACE), defined as a composite of death, myocardial infarction or ischemic stroke, were identified for patients with and without renal disease. All-cause hospital readmissions within 6 months of discharge were determined for all survivors.

RESULTS

Among 39,441 patients with PAD hospitalized for LE revascularization, 10,530 had renal disease (26.7%), of whom 69% had CKD without ESRD and 31% had ESRD. Patients with renal disease were more likely to have MACE after LE revascularization (5.2% vs. 2.5%; adjusted OR [aOR] 1.74, 95% CI 1.40-2.16), require LE amputation (26.1% vs. 12.2%; aOR 1.33, 95% CI 1.19-1.50), and require hospital readmission within 6 months (61.0% vs. 43.6%; adjusted HR [aHR] 1.38, 95% CI 1.28-1.48) compared to those without renal disease.

CONCLUSIONS

Renal disease is common among patients undergoing LE revascularization for PAD and was independently associated with in-hospital MACE, LE amputation, and hospital readmission within 6 months. Additional efforts to improve outcomes of patients with renal disease and PAD requiring LE revascularization are necessary.

Acute kidney injury in patients undergoing endovascular therapy for critical limb ischemia

BACKGROUND

Similar to coronary angiography and interventions, patients undergoing percutaneous treatment of lower extremity peripheral arterial disease are also at risk of acute kidney injury (AKI). The incidence, risk factors associations, need for dialysis and inhospital mortality related to AKI in patients with critical limb ischemia (CLI) following endovascular therapy is poorly defined.

OBJECTIVES

The purpose of this study was to analyze data from the National Inpatient Sample (NIS) to determine the aforementioned outcomes in patients with CLI.

METHODS

Using the full NIS admission dataset from 2003 through 2012, ICD-9 codes relevant to comorbid conditions, procedure codes, composite codes for AKI, and inhospital mortality were analyzed using multivariate models.

RESULTS

A total of 273,624 patients were included with a mean age of 70.0 ± 27.4 years, 46.0% were female, 57.2% had diabetes, 43.4% had coronary artery disease (CAD), and 29.2% had chronic kidney disease (CKD). The overall rate of AKI was 10.4%, and there was a temporal rise over the analysis period in AKI incidence (p < .001). Age, diabetes, CKD, and heart failure were all associated with AKI (p < .0001). The inhospital mortality rate in the patients with AKI declined over time but was higher than in patients without AKI (6.0% vs. 1.4%), p < .0001. The mortality rate was substantially higher in patients with AKI requiring dialysis as compared to AKI not requiring dialysis (13.4% vs. 5.6%), p < .0001.

CONCLUSIONS

AKI is associated with age, CKD, and heart failure. The incidence of AKI following endovascular therapy for CLI is rising and independently associated with inhospital mortality.

Predictors of mortality and outcomes after retrograde endovascular angioplasty in patients with peripheral artery disease

Introduction

Endovascular revascularization (ER) techniques in patients with peripheral artery disease (PAD) have been developed and became more accessible in recent years. The ER is a first-line treatment in the majority of patients with symptomatic PAD. However, data on assessment of predictors of long-term outcomes of retrograde ER in patients with PAD are scarce.

Aim

To evaluate predictors of long-term outcomes of retrograde ER in patients with chronic total occlusion in lower limb arteries.

Material and methods

We analyzed data of 834 patients who underwent retrograde ER. Baseline clinical characteristics and procedural data were collected. Patients were followed up for 36 months, and the primary endpoint was all-cause mortality.

Results

All patients were symptomatic and had failed antegrade ER. The procedural success rate was 92%. Cumulative all-cause mortality was 13.4% at 36-month follow-up. In multivariate analysis history of stroke, Rutherford category, chronic limb ischemia, chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD) and previous ER of other lesion were independent predictors of a higher mortality rate after 36 months (hazard ratio (HR) for stroke 2.4, 95% confidence interval (CI): 1.55–3.66; p = 0.0002; HR for age per 10 years 1.37, 95% CI: 1.15–1.64; p = 0.0002; HR for Rutherford category 1.63, 95% CI: 1.35–1.98; p < 0.0001, HR for chronic limb ischemia 0.44, 95% CI: 0.25–0.8, p = 0.007; HR for CKD 1.73, 95% CI: 1.14–2.56, p = 0.01; HR for COPD 2.4, 95% CI: 1.5–3.7, p = 0.0004; HR for previous ER 0.59, 95% CI: 0.35–0.94, p = 0.02).

Conclusions

History of stroke, Rutherford category, chronic limb ischemia, CKD, COPD, and previous ER of other lesion were independently associated with increased risk of all-cause death.

The Black Esophagus in the Renal Transplant Patient

Acute esophageal necrosis (AEN) is an uncommon disease characterized by gastrointestinal bleeding and endoscopic findings of circumferential black-colored necrosis of the distal esophagus. Patients at risk include elderly males over the age of 65, who typically have multiple chronic medical issues including vascular disease and diabetes. Mortality is reported to be 32%. Here, we present a case of AEN in a renal transplant patient and describe potential inciting factors such as immunosuppression and opportunistic diseases.

Chronic kidney disease and risk for cardiovascular and limb outcomes in patients with symptomatic peripheral artery disease: The EUCLID trial

In patients with symptomatic peripheral artery disease (PAD), the impact of chronic kidney disease (CKD) on major adverse cardiovascular events has not been fully evaluated. The Examining Use of Ticagrelor In PAD (EUCLID) trial randomized 13,885 patients with PAD to ticagrelor 90 mg twice daily or clopidogrel 75 mg daily. This post hoc analysis compared the incidence of the primary composite endpoint (cardiovascular death, myocardial infarction (MI), or ischemic stroke) in patients with CKD (eGFR < 60 mL/min/1.73 m2) with those without CKD (eGFR ⩾ 60 mL/min/1.73 m2). The primary safety endpoint was thrombolysis in MI (TIMI) major bleeding. A total of 13,483 patients were included; 3332 (25%) had CKD, of whom 237 had stage 4/5 disease. Median follow-up was approximately 30 months. After statistical adjustment, patients with CKD had a higher rate of the primary endpoint compared with those without CKD (6.75 vs 3.72 events/100 patient-years; adjusted hazard ratio (HR) 1.45, 95% CI 1.30–1.63). CKD was not associated with increased risk of hospitalization for acute limb ischemia (ALI) (adjusted HR 0.96, 95% CI 0.69–1.34) or major amputation (adjusted HR 0.92, 95% CI 0.66–1.28). CKD was not associated with a significantly increased risk of major bleeding (adjusted HR 1.21, 95% CI 0.89–1.64), but minor bleeding was significantly increased (adjusted HR 1.51, 95% CI 1.07–2.15). In conclusion, patients with PAD and CKD had higher rates of cardiovascular death, MI, and ischemic stroke, but similar rates of ALI, major amputation, and TIMI major bleeding when compared with patients without CKD. ClinicalTrials.gov Identifier: NCT01732822

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.

Unique aspects of peripheral artery disease in patients with chronic kidney disease

Peripheral artery disease (PAD) represents a major health care burden. Despite the advent of screening and interventional procedures, the long-term clinical outcomes remain suboptimal, especially in patients with chronic kidney disease (CKD). While CKD and PAD share common predisposing factors, emerging studies indicate that their co-existence is not merely an association; instead, CKD represents a strong, independent risk factor for PAD. These findings implicate CKD-specific mediators of PAD that remain incompletely understood. Moreover, there is a need to understand the mechanisms underlying poor outcomes after interventions for PAD in CKD. This review discusses unique clinical aspects of PAD in patients with CKD, including high prevalence and worse outcomes after vascular interventions and the influence of renal allograft transplantation. In doing so, it also highlights underappreciated aspects of PAD in patients with CKD, such as disparities in revascularization and higher peri-procedural mortality. While previous reviews have discussed general mechanisms of PAD pathogenesis, focusing on PAD in CKD, this review underscores a need to probe for CKD-specific pathogenic pathways that may unravel novel biomarkers and therapeutic targets in PAD and ultimately improve the risk stratification and management of patients with CKD and PAD.

Alprostadil treatment of critical limb ischemia in hemodialysis patients : A retrospective single-center analysis

BACKGROUND

Peripheral artery disease and critical limb ischemia are common in patients undergoing chronic hemodialysis treatment and are associated with a high rate of amputation and mortality. The effect of treatment with prostanoids in this specific group of patients is unknown.

METHODS

A retrospective single-center analysis of hemodialysis patients with critical limb ischemia was performed who were treated with the prostanoid analogue alprostadil as an infusion during hemodialysis in the period from 2000 to 2013. The primary study outcome was a combined end-point including amputation and death 1 year after start of alprostadil. Kaplan-Meier curves were used to describe amputation-free survival and overall survival. A multivariable adjusted Cox proportional hazards model was calculated for the primary outcome.

RESULTS

A total of 86 patients (60 males, 69.7%) were studied. The median alprostadil treatment period was 1.8 months. The 1‑year amputation-free survival was 41%. In 36% of patients an amputation was necessary and 35% died. Despite alprostadil treatment, 36% of the study patients additionally underwent an endovascular procedure and 16% had bypass surgery. Men had a significantly higher amputation rate (45%) than women (15%) (P = 0.009). Male sex and dialysis vintage were significantly associated with an increased risk for primary outcome CONCLUSIONS: Despite treatment with alprostadil the mortality, amputation rate and the need for revascularization procedures in hemodialysis patients with critical limb ischemia remained high. The outcome, however, was comparable with that of other treatment, such as endovascular procedures and bypass surgery. The effect of any current treatment strategy on amputation rate or mortality in that patient group remains uncertain.