Trends in Rates of Lower Extremity Amputation Among Patients With End-stage Renal Disease Who Receive Dialysis

Risk factors of foot ulcers in patients with end-stage renal disease on dialysis: A meta-analysis

The present study aims to assess the risk factors for foot ulcers in patients undergoing dialysis for end-stage renal disease (ESRD) and to provide evidence-based guidance for prevention and treatment. A systematic search was conducted on PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database and Wanfang Data from the database inception until May 2023 to identify relevant studies investigating the risk factors for foot ulcers in dialysis patients with ESRD. Two independent researchers conducted the literature screening and data extraction. The meta-analysis was performed using STATA 17.0 software. Ultimately, six articles comprising 1620 patients were included for analysis. The meta-analysis revealed that male (OR, 1.464; 95% CI: 1.082-1.980, p = 0.013), hypertension (OR, 1.781; 95% CI: 1.293-2.4550, p < 0.001), peripheral artery disease (PAD) (OR, 5.014; 95% CI: 2.514-9.998, p < 0.001), type 1 diabetes mellitus (T1DM) (OR, 2.993; 95% CI: 1.477-6.065, p = 0.002) and type 2 diabetes mellitus (T2DM) (OR, 2.498; 95% CI:1.466-4.256, p = 0.001) were risk factors for foot ulcers in dialysis patients with ESRD. Conversely, the female sex (OR, 0.683; 95% CI: 0.505-0.924, p = 0.013) was a protective factor against foot ulcers. Our analysis revealed that male sex, hypertension, PAD, T1DM and T2DM were risk factors for foot ulcers in patients undergoing dialysis for ESRD. Conversely, the female sex was a protective factor against foot ulcers. Therefore, it is crucial to strengthen health education that targets patients with these risk factors and regularly screen high-risk individuals. Early detection and treatment can help delay disease progression.

Endovascular versus Surgical Lower Extremity Revascularization among Patients with Chronic Kidney Disease

Introduction

Patients with chronic kidney disease (CKD) have a high prevalence of peripheral artery disease. How best to manage lower extremity peripheral artery disease remains unclear in this patient population. We therefore sought to compare the outcomes after endovascular versus surgical lower extremity revascularization among patients with CKD.

Methods

We used data from Optum's de-identifed Clinformatics® Data Mart Database, a nationwide database of commercially insured persons in the United States to study patients with CKD who underwent lower extremity endovascular or surgical revascularization. We used inverse probability of treatment weighting to balance covariates. We employed proportional hazard regression to study the primary outcome of major adverse limb events (MALE), defined as a repeat revascularization or amputation. We also studied each of these events separately and death from any cause.

Results

In our cohort, 60,057 patients underwent endovascular revascularization and 9,338 patients underwent surgical revascularization. Endovascular revascularization compared with surgical revascularization was associated with a higher adjusted hazard of MALE (hazard ratio (HR) 1.52; 95% confidence interval (CI) 1.46-1.59). Endovascular revascularization was also associated with a higher adjusted hazard of repeat revascularization (HR 1.65; 95% CI 1.57-1.72) but a lower adjusted risk of amputation (HR 0.71; CI 0.73-0.89). Patients undergoing endovascular revascularization also had a lower adjusted hazard for death from any cause (0.85; CI 0.82-0.88).

Conclusions

In this analysis of patients with CKD undergoing lower extremity revascularization, an endovascular approach was associated with a higher rate of repeated revascularization but a lower risk of subsequent amputation and death compared with surgical revascularization. Multiple factors must be considered when counseling patients with CKD, who have a high burden of comorbid conditions. Clinical trials should include more patients with kidney disease, who are often otherwise excluded from participation, to better understand the most effective treatment strategies for this vulnerable patient population.

Comorbid status in patients with osteomyelitis is associated with long-term incidence of extremity amputation

INTRODUCTION

Osteomyelitis is associated with significant morbidity, including amputation. There are limited data on long-term amputation rates following an osteomyelitis diagnosis. We sought to determine the incidence of amputation in patients with osteomyelitis over 2 years.

RESEARCH DESIGN AND METHODS

Observational cohort study of 1186 inpatients with osteomyelitis between 2004 and 2015 and stratified by osteomyelitis location status to evaluate the impact on amputation, mortality rates, readmission data, and inpatient days.

RESULTS

Persons with diabetes had 3.65 times greater probability of lower extremity amputation (p<0.001), readmission (p<0.001), and longer inpatient stay (p<0.001) and had higher 2-year mortality (relative risk (RR) 1.23, p=0.0027), adjusting for risk factors. Male gender (RR 1.57, p<0.001), black race (RR 1.41, p<0.05), former smoking status (RR 1.38, p<0.01), myocardial infarction (RR 1.72, p<0.001), congestive heart failure (RR 1.56, p<0.001), peripheral vascular disease (RR 2.25, p<0.001) and renal disease (RR 1.756, p<0.001) were independently associated with amputation. Male gender (RR 1.39, p<0.01), black race (RR 1.27, p<0.05), diabetes (RR 2.77, p<0.001) and peripheral vascular disease (RR 1.59, p<0.001) had increased risk of lower, not upper, extremity amputation.

CONCLUSIONS

Patients with osteomyelitis have higher rates of amputation and hospitalization. Clinicians must incorporate demographic and comorbid risk factors to protect against amputation.

Renal function is highly associated with podiatric risk in diabetic patients

Background

Chronic kidney disease (CKD) is correlated with the incidence of diabetic foot ulcer (DFU). Furthermore, the International Working Group on the Diabetic Foot (IWGDF) has proposed a classification of the risk factors for DFU. The purpose of this study was to investigate the relationship between the IWGDF risk classification and the glomerular filtration rate level estimated by the CKD Epidemiology Collaboration formula (eGFR).

Methods

We conducted a prospective multicentric study. Patients were recruited from either diabetology or nephrology departments. The secondary objectives were to determine this relationship after excluding people on dialysis and to identify the factors associated with podiatric risk.

Results

Four hundred and eighty-six patients were included, with a mean age of 64.2 years (±15.7) and a mean diabetes duration of 15.7 years (±12.1). Based on the IWGDF classification, 53.5% of the population were in podiatric stage 0, 11.7% in stage 1 and 34.8% in stage 2 or 3. The mean eGFR level was significantly lower in patients with podiatric risk ≥2 (36.8 ± 33.9 mL/min/1.73 m2 vs 71.9 ± 35.3 mL/min/1.73 m2, P < .0001) and a significant association was found between the eGFR and the podiatric risk. This association remained significant after the exclusion of the hemodialysis patients. After receiver operating characteristic analysis, a cutoff of 45 ± 11 mL/min/1.73 m2 (area under the curve 0.76) was found discriminant to define a group of CKD patients at higher risk for podiatric stage ≥2.

Conclusion

eGFR levels are linked to podiatric stages in diabetes mellitus. Patients with eGFR <45 mL/min/1.73 m2 and dialysis patients should be carefully managed in collaboration with diabetic foot specialized centers.

The relationship between lower extremity amputation and body mass index

OBJECTIVES

Non-traumatic lower extremity amputation (LEA) is associated with significant morbidity and mortality. Diabetes mellitus (DM) and peripheral vascular disease (PVD) are associated with increased risk for LEA. As such, DM and PVD account for 54% of all LEA's, performed in the United States annually. As obesity is highly associated with both DM and PVD, our study sought to explore the relationship between LEA and obesity defined by BMI.

METHODS

Using the National Inpatient Sample (NIS) database, a retrospective review of patients who underwent non-traumatic LEA (LEA) between 2008 and 2014 was performed. The International Classification of Diseases 9th edition (ICD-9) codes were utilized to determine the diagnoses, comorbidities, and procedures. Patient BMIs were classified as follows: Non-obese [BMI <30], Obesity class I [BMI 30-34.9], Obesity class II [BMI 35-39.9], and Obesity class III [BMI ≥40]. Predictors for LEA were compared between groups using chi-square test and binary logistic regression to identify possible underlying factors associated with LEA. We also conducted a multivariate analysis to measure the effect of multiple variables on LEA.

RESULTS

We identified 16,259 patients with non-traumatic LEA and a mean age of 59.9 years. Rate of amputation in females was lower than males at 0.35% vs 0.87% respectively (p < 0.001). Of patients that underwent amputation there was a V-shape trend based on BMI, with 30.4% in non-obese patients, 18.2% in obesity class I, 17.3% in obesity class II, and 34.1% in obesity class III. The incidence of diabetes increased with obesity class, while the incidence of PVD decreased. Interestingly, of those with DM there was an inverse relationship between amputation rate and BMI class, with LEA rates in non-obese versus obesity class III patients were 1.63% vs 0.98% respectively (p < 0.001). Similarly, patients who had both diabetes and PVD showed a downward trend in LEA rate as obesity class increased; non-obese patients had a LEA rate of 8.01%, while obesity class III had 4.65% (p < 0.001). Patients in higher income bracket have lower odds of LEA (OR 0.77, p < 0.001) compared to the lowest income patients. Also, patients with comorbidities such as PVD (OR 10.78), diabetes (OR 5.02), renal failure (OR 1.41), and hypertension (OR 1.36) had higher odds to get an LEA (p < 0.001). Individuals with obesity class III are almost at half the odds (OR 0.52) to get an LEA compared to non-obese (p < 0.001).

CONCLUSIONS

Higher BMI and female gender are protective factors against lower extremity amputation. Factors that predisposing to LEA include lower household income and certain comorbidities such as PVD, diabetes, renal failure, and hypertension. These findings warrant further research to identify patients at high risk for LEA and help develop management guidelines for targeted populations.

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.

Clinical characteristics and risk factors of lower extremity amputation in the diabetic inpatients with foot ulcers

OBJECTIVES

To analyze clinical characteristics of the diabetic inpatients with foot ulcers and explore the risk factors of lower extremity amputation (LEA) in West China Hospital of Sichuan University.

METHODS

A retrospective analysis was performed based on the clinical data of the patients with diabetic foot ulcer (DFU) hospitalized in West China Hospital of Sichuan University from January 1, 2012 to December 31, 2020. The DFU patients were divided into three groups: non-amputation, minor amputation, and major amputation groups. The ordinal logistic regression analysis was used to identify the risk factors for LEA.

RESULTS

992 diabetic patients (622 males and 370 females) with DFU were hospitalized in the Diabetic Foot Care Center of Sichuan University. Among them, 72 (7.3%) (55 minor amputations and 17 major amputations) cases experienced amputation, and 21(2.1%) refused amputation. Excluding the patients who refused amputation, the mean age and duration of diabetes of and HbA1c the 971 patients with DFU, were 65.1 ± 12.3 years old, 11.1 ± 7.6 years, and 8.6 ± 2.3% respectively. The patients in the major amputation group were older and had longer course of diabetes for a longer period of time than those in the non-amputation and minor amputation groups. Compared with the non-amputation patients (55.1%), more patients with amputation (minor amputation (63.5%) and major amputation (88.2%)) suffered from peripheral arterial disease (P=0.019). The amputated patients had statistically lower hemoglobin, serum albumin and ankle brachial index (ABI), but higher white blood cell, platelet counts, fibrinogen and C-reactive protein levels. The patients with amputation had a higher incidence of osteomyelitis (P = 0.006), foot gangrene (P < 0.001), and a history of prior amputations (P < 0.001) than those without amputation. Furthermore, a history of prior amputation (odds ratio 10.194; 95% CI, 2.646-39.279; P=0.001), foot gangrene (odds ratio 6.466; 95% CI, 1.576-26.539; P=0.010) and ABI (odds ratio 0.791; 95% CI, 0.639-0.980; P = 0.032) were significantly associated with LEAs.

CONCLUSIONS

The DFU inpatients with amputation were older with long duration of diabetes, poorly glycemic control, malnutrition, PAD, severe foot ulcers with infection. A history of prior amputation, foot gangrene and a low ABI level were the independent predictors of LEA. Multidisciplinary intervention for DFU is essential to avoid amputation of the diabetic patients with foot ulcer.

Diabetic foot disease in subjects with End-stage renal Disease: A nationwide study over 14 years highlighting an emerging threat

AIMS

To disclose prevalence, demographic, foot characteristics as well as management and lower-extremity amputations (LEAs) of subjects with end-stage renal disease (ESRD) on diabetic foot diseases (DFDs).

METHODS

Data were derived from the Taiwan National Health Insurance Research Database between 2004 and 2017. DFDs were defined as ulcers, infections, or severe peripheral arterial diseases (PADs) in patients with type 2 diabetes. Clinical characteristics were analyzed between subjects with and without ESRD.

RESULTS

Subjects with ESRD have increased impacts on the DFD population either from annual prevalence (2.7 % to 10.42 %, P for trend < 0.001), or proportional representation in LEAs (7.91 % to 26.37 %, P < 0.001) over 14 years. The annual trends for major-LEAs rates have decreased in both subjects with and without ESRD (13.67 % to 5.82 % and 3.48 % to 1.47 %, both P < 0.001). Notably, the concomitant increase of endovascular treatments (EVTs) (7.09 % to 29.41 %, P < 0.001) was associated with the decrease of major-LEAs (P for interaction < 0.001) in subjects with ESRD.

CONCLUSIONS

As the annual prevalence of subjects with ESRD has increased 3.9-fold over years, they now account for more than 30% of annual major-LEA of the total DFD population. Interdisciplinary team approach and aggressive EVTs might reduce major-LEAs in these patients.

Excess all-cause and cause-specific mortality for people with diabetes and end-stage kidney disease

AIMS

Excess mortality is high in the setting of diabetes and end-stage kidney disease (ESKD), but the effects of ESKD beyond diabetes itself remains incompletely understood. We examined excess mortality in people with diabetes with versus without ESKD, and variation by age, sex and diabetes type.

METHODS

This study included 63,599 people with type 1 (aged 20-69 years; 56% men) and 1,172,160 people with type 2 diabetes (aged 30+ years; 54% men), from the Australian National Diabetes Services Scheme. Initiation of renal replacement therapy and mortality outcomes were obtained via linkage to the Australia and New Zealand Dialysis and Transplant Registry and the National Death Index, respectively. Excess mortality was measured by calculating the mortality rate ratio (MRR) for people with versus without ESKD via indirect standardisation.

RESULTS

A total of 9027 people developed ESKD during 8,601,522 person-years of follow-up. Among people with type 1 diabetes, the MRR was 34.9 (95%CI: 16.6-73.1) in men and 41.5 (20.8-83.1) in women aged 20-29 years and was 5.6 (4.5-7.0) and 7.4 (5.5-10.1) in men and women aged 60-69 years, respectively. In type 2 diabetes, MRRs were 16.6 (8.6-31.8) and 35.8 (17.0-75.2) at age 30-39 years and were 2.8 (2.6-3.1) and 3.6 (3.2-4.1) at age 80+ years in men and women, respectively. Excess cause-specific mortality was highest for peripheral artery disease, cardiac arrest, and infections, and lowest for cancer.

CONCLUSIONS

Among people with diabetes, excess mortality in ESKD is much higher at younger ages and is higher for women compared with men.

Clinical factors and mortality rates for non-traumatic upper extremity amputations

Non-traumatic upper extremity amputations are an increasing concern with the rising prevalence of diabetes mellitus. To ascertain the risk factors and mortality rates for these amputations, the demographic information, amputation history, comorbidities and clinical outcomes of 140 patients who underwent non-traumatic upper extremity amputations between 1 January 2004 and 31 October 2017 were studied. Correlations were assessed using Cochran-Armitage chi-squared tests, odds ratios and multivariate binomial logistic regression as appropriate. Diabetes mellitus, coronary artery disease, end-stage renal failure, peripheral arterial disease and prior lower extremity amputation were significant risk factors for multiple upper extremity amputations. One-year, 2-year and 5-year mortality rates were 12%, 15% and 38%, respectively, following first upper extremity amputation. The risk factors for upper extremity amputations correspond with those for lower extremity amputations, comprising mainly diabetes mellitus and its related comorbidities. The mortality rates for non-traumatic upper extremity amputations highlight their significant burden on patients.Level of evidence: III.

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).

Factors that affect the one-year mortality rate after lower limb amputation in the Hong Kong Chinese population

Introduction

Lower limb amputation has significant morbidity and mortality. This study reviews the potential factors affecting the one-year mortality rate after lower limb amputation in the Hong Kong Chinese population.

Methods

Cases with lower limb amputations (toe, ray, below-knee, and above-knee amputations) from a regional hospital from January 2016 to December 2017 were recruited. Amputations due to trauma were excluded. The one-year mortality rate and the potential risk factors (age, sex, length-of-stay, multiple operations, extent of surgery (minor vs. major), medical comorbidities including (1) end-stage renal failure (ESRF), (2) cardiac diseases, (3) ischemic heart disease, (4) peripheral vascular disease and (5) diabetes mellitus) were analyzed by multiple logistic regression using Matlab 2018a.

Results

A total of 132 patients were recruited (173 operations). The one-year mortality rate was 36.3%. The mean age at death was 72.2 years. The results of the regression analysis showed patients having ESRF (β = 2.195, t 120 = 3.008, p = 0.003) or a major amputation (including above- or below-knee amputation) (β = 1.079, t 120 = 2.120, p = 0.034), had a significantly higher one-year mortality. The remaining factors showed no significant effect. The one-year mortality rate in ESRF patients was 77.8%; while the one-year mortality rate without ESRF was 29.8%. The mean age at death in the ESRF group was 62.9 years; while that without ESRF was 76.1 years. The one-year mortality for patients with major amputation was 45.8% while that for minor amputation was 20.4%.

Conclusion

ESRF and major amputation are factors that increase the one-year mortality rate after lower limb amputation.

Younger patients with chronic limb threatening ischemia face more frequent amputations

INTRODUCTION

Amputations among younger patients with chronic limb threatening ischemia (CLTI) may carry higher personal and societal costs, but younger patients are often not included in CLTI research because of dataset limitations. We aimed to characterize and compare outcomes between younger (<65 years old) and older patients with CLTI.

METHODS

This retrospective cohort study identified patients with CLTI between July 1, 2014 and December 31, 2017 in the MarketScan commercial claims database, a proprietary set of claims for over 50 million patients with private insurance in the United States. The primary outcome was major adverse limb events (MALE); secondary outcomes included amputations, major adverse cardiovascular events, and statin prescription fills.

RESULTS

The study cohort included 64,663 people with CLTI, of whom 25,595 (39.6%) were <65 years old. Younger patients were more likely to have diabetes mellitus (54.1% versus 49.9%, P<.001) but less likely to have other comorbidities. A higher proportion of younger patients suffered MALE (31.7% versus 30.2%, P=.002), specifically amputation (11.5% versus 9.3%, P<.001). After adjustment, age <65 years old was associated with a 24% increased risk of amputation (HR_adj 1.24, 95%CI 1.18-1.32, P<.001) and a 10% increased risk of MALE (HR_adj 1.10, 95%CI 1.07-1.14, P<.001).

CONCLUSIONS

A significant proportion of commercially insured patients with CLTI are under the age of 65, and younger patients have worse limb-related outcomes. These findings highlight the importance of aggressively treating risk factors for atherosclerosis and intentionally including younger patients with CLTI in future analyses to better understand their disease patterns and outcomes.

Transfusion in orthopaedic surgery : a retrospective multicentre cohort study

Aims

Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements.

Methods

We performed a retrospective cohort study of adult patients who underwent orthopaedic surgery at four Canadian hospitals between 2014 and 2016. We studied all patients admitted to hospital for nonarthroscopic joint surgeries, amputations, and fracture surgeries. For each surgery and surgical subgroup, we characterized the proportion of patients who received red blood cell (RBC) transfusion, the mean/median number of RBC units transfused, and exposure to platelets and plasma.

Results

Of the 14,584 included patients, the most commonly performed surgeries were knee arthroplasty (24.8%), hip arthroplasty (24.6%), and hip fracture surgery (17.4%). A total of 10.3% of patients received RBC transfusion; the proportion of patients receiving RBC transfusions varied widely based on the surgical subgroup (0.0% to 33.1%). Primary knee arthroplasty and hip arthroplasty, the two most common surgeries, were associated with in-hospital transfusion frequencies of 2.8% and 4.5%, respectively. RBC transfusion occurred in 25.0% of hip fracture surgeries, accounting for the greatest total number of RBC units transfused in our cohort (38.0% of all transfused RBC units). Platelet and plasma transfusions were uncommon.

Conclusion

Orthopaedic surgeries were associated with variable rates of transfusion. The rate of RBC transfusion is highly dependent on the surgery type. Identifying surgeries with the highest transfusion rates, and further evaluation of factors that contribute to transfusion in identified at-risk populations, can serve to inform perioperative planning and blood bank requirements, and facilitate pre-emptive transfusion mitigation strategies.

Cite this article: Bone Jt Open 2021;2(10):850–857.

Anticoagulation in patients with kidney failure on dialysis: factor XI as a therapeutic target

Chronic kidney disease is present in almost 10% of the world population and is associated with excess mortality and morbidity. Reduced glomerular filtration rate and the presence and extent of proteinuria, key domains of chronic kidney disease, have both been shown to be strong and independent risk factors for cardiovascular disease. Patients with kidney failure requiring dialysis are at highest risk for cardiovascular events (e.g., stroke or myocardial infarction), and of developing chronic cardiovascular conditions, such as heart failure. Despite the high burden of cardiovascular disease, there is a paucity of evidence supporting therapies to reduce this risk. Although long-term anticoagulant treatment has the potential to prevent thromboembolism in persons with kidney failure on dialysis, this possibility remains understudied. The limited data available on anticoagulation in patients with kidney failure has focused on vitamin K antagonists or direct oral anticoagulants that inhibit thrombin or factor (F) Xa. The risk of bleeding is a major concern with these agents. However, FXI is emerging as a potential safer target for new anticoagulants because FXI plays a greater part in thrombosis than in hemostasis. In this article, we (i) explain the rationale for considering anticoagulation therapy in patients with kidney failure to reduce atherothrombotic events, (ii) highlight the limitations of current anticoagulants in this patient population, (iii) explain the potential benefits of FXI inhibitors, and (iv) summarize ongoing studies investigating FXI inhibition in patients with kidney failure on dialysis.

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.

Temporal Trends in Incidence Rates of Lower Extremity Amputation and Associated Risk Factors Among Patients Using Veterans Health Administration Services From 2008 to 2018

IMPORTANCE

Lower extremity amputation (LEA) is associated with significant morbidity and mortality. However, national temporal trends of LEA incidence rates among US veterans and associated factors have not been well characterized.

OBJECTIVE

To describe the temporal trends of LEA, characterize associated risk factors, and decompose the associations of these risk factors with changes in temporal trends of LEA among US veterans using Department of Veteran Affairs (VA) services between 2008 and 2018.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used VA data from 2008 to 2018 to estimate incidence rates of LEA among veterans using VA services. Cox regression models were used to identify risk factors associated with LEA. Decomposition analyses estimated the associations of changes in prevalence of risk factors with changes in LEA rates. Data were analyzed from October 1, 2007, to September 30, 2018.

MAIN OUTCOMES AND MEASURES

Toe, transmetatarsal, below-knee, or above-knee LEA.

RESULTS

A total of 6 493 141 veterans were included (median [interquartile range] age, 64 [54-76] years; 6 060 390 [93.4%] men). Veterans were studied for a median (interquartile range) of 10.9 (5.6-11.0) years. Between 2008 and 2018, rates of LEA increased from 12.89 (95% CI, 12.53-13.25) LEA per 10 000 persons to 18.12 (95% CI, 17.70-18.54) LEA per 10 000 persons, representing a net increase of 5.23 (95% CI, 4.68-5.78) LEA per 10 000 persons. Between 2008 and 2018, toe amputation rates increased by 3.24 (2.89-3.59) amputations per 10 000 persons, accounting for 62.0% of the total increase in LEA rates. Transmetatarsal amputations increased by 1.54 (95% CI, 1.27-1.81) amputations per 10 000 persons; below-knee amputation rates increased by 0.81 (95% CI, 0.56-1.05) amputations per 10 000 persons; and above-knee amputation rates decreased by 0.37 (95% CI, 0.14-0.59) amputations per 10 000 persons. Compared with men, women had decreased risk of any LEA (hazard ratio [HR], 0.34 [95% CI, 0.31-0.37]). Factors associated with increased risk of any LEA included Black race (HR, 1.25 [95% CI, 1.21-1.28]) or another non-White race (ie, Asian, Latino, or other; HR, 2.36 [95% CI, 2.30-2.42]), obesity (HR, 1.59 [95% CI, 1.55-1.63]), diabetes (HR, 6.38 [95% CI, 6.22-6.54]), chronic kidney disease (CKD; eg, CKD stage 5: HR, 3.94 [95% CI, 3.22-4.83]), and smoking status (eg, current smoking: HR, 1.97 [95% CI, 1.92-2.03]). Decomposition analyses suggested that while changes in demographic composition, primarily driven by increased proportion of women veterans, associated with a decrease of 0.18 (95% CI, 0.14-0.22) LEA per 10 000 persons, and decreases in smoking rates, associated with a decrease of 0.88 (95% CI, 0.79-0.97) LEA per 10 000 persons. However, these were overwhelmed by increased rates of diabetes, associated with an increase of 1.86 (95% CI, 1.72-1.99) LEA per 10 000 persons; peripheral arterial disease, associated with an increase of 1.53 (95% CI, 1.41-1.65) LEA per 10 000 persons; CKD, associated with an increase of 1.45 (95% CI, 1.33-1.57) LEA per 10 000 persons; and other clinical factors, including body mass index, cancer, cardiovascular disease, cerebrovascular disease, chronic lung disease, dementia, and hypertension, associated with an increase of 1.45 (95% CI, 1.33-1.57) LEA per 10 000 persons.

CONCLUSIONS AND RELEVANCE

This cohort study found that incidence rates of LEA among veterans using VA services increased between 2008 and 2018. Efforts aimed at reducing burden of LEA should target the reduction of diabetes, peripheral arterial disease, and CKD at the individual and population levels.

Targeting Uremic Toxins to Prevent Peripheral Vascular Complications in Chronic Kidney Disease

Chronic kidney disease (CKD) exhibits progressive kidney dysfunction and leads to disturbed homeostasis, including accumulation of uremic toxins, activated renin-angiotensin system, and increased oxidative stress and proinflammatory cytokines. Patients with CKD are prone to developing the peripheral vascular disease (PVD), leading to poorer outcomes than those without CKD. Cumulative evidence has showed that the synergy of uremic milieu and PVD could exaggerate vascular complications such as limb ischemia, amputation, stenosis, or thrombosis of a dialysis vascular access, and increase mortality risk. The role of uremic toxins in the pathogenesis of vascular dysfunction in CKD has been investigated. Moreover, growing evidence has shown the promising role of uremic toxins as a therapeutic target for PVD in CKD. This review focused on uremic toxins in the pathophysiology, in vitro and animal models, and current novel clinical approaches in reducing the uremic toxin to prevent peripheral vascular complications in CKD patients.

Indoxyl Sulfate and Incident Peripheral Artery Disease in Hemodialysis Patients

Peripheral artery disease (PAD) is highly prevalent among patients with chronic kidney disease (CKD) and portends a very poor prognosis. Indoxyl sulfate has been shown to induce atherothrombosis and impaired neovascularization in uremic mice. However, there is no clinical evidence regarding the role of indoxyl sulfate in PAD associated with CKD. We examined associations between indoxyl sulfate and incident symptomatic lower extremity PAD events as well as major adverse cardiovascular events (MACE) and all-cause mortality using Cox proportional hazards models in a prospective cohort of 200 hemodialysis patients free of PAD at baseline. Patients were considered as having PAD if they developed PAD symptoms confirmed by an ankle-brachial index with waveforms, duplex ultrasound or angiography, and/or major adverse limb events including revascularization and amputation. During a median follow-up of 6.5 years, 37 patients (18.5%) experienced incident symptomatic PAD. MACE occurred in 52 patients, and a total of 85 patients died. After adjusting for traditional risk factors for PAD, including age, current smoking, diabetes, and cardiovascular disease, indoxyl sulfate was significantly associated with the risk of PAD (hazard ratio (HR), 1.19 for every 10-μg/mL increase in indoxyl sulfate; 95% confidence interval (CI), 1.05–1.35). However, indoxyl sulfate was not associated with risk of MACE (HR, 1.00; 95% CI, 0.90–1.12) or death from any cause (HR, 0.98; 95% CI, 0.90–1.07). Indoxyl sulfate was associated with incident symptomatic PAD but not with MACE or all-cause mortality, suggesting that indoxyl sulfate toxicity may be unique to PAD among hemodialysis patients.

Hemodialysis is Not Associated With Pre-prosthetic Inpatient Rehabilitation Outcomes After Dysvascular Lower Extremity Amputation: A Retrospective Cohort Study

BACKGROUND

Lower extremity amputation due to complications from peripheral vascular disease and/or diabetes are common and these patients often have multiple comorbidities. Patients with end-stage renal disease receiving hemodialysis (ESRD/HD) are a particularly vulnerable group at risk for amputation. After lower extremity amputation (LEA) surgery, many patients undergo post-operative inpatient rehabilitation to improve their pre-prosthetic functional independence. Given the increased complexity of dysvascular patients living with ESRD/HD compared to those without ESRD/HD, the association of HD with pre-prosthetic inpatient functional outcomes warrants further study.

OBJECTIVE

The objective of this study was to compare the pre-prosthetic functional outcomes and Length of Stay (LOS) among patients with recent dysvascular LEA with and without ESRD/HD.

METHODOLOGY

A retrospective cohort design was used to analyze a group of 167 patients with unilateral, dysvascular limb loss who were admitted to inpatient rehabilitation with 24 of these patients in the ESRD/HD group. Age, gender, amputation level, amputation side, length of stay (LOS), time since surgery, Functional Independence Measure (FIM) scores (admission and discharge), and Charlson Comorbidity Index (CCI) were collected.

FINDINGS

There was no difference between patients with dysvascular amputation with and without ESRD/HD in the association of functional outcomes or LOS in this cohort and rehabilitation model. The CCI score was higher in the ESRD/HD group. Multivariate analysis indicated an inverse relationship with age and FIM scores, where increased age was associated with lower Total and Motor FIM at admission and discharge. There were no associations with FIM change. Age was positively associated with LOS. Being female was inversely associated to motor FIM scores at admission and discharge.

CONCLUSION

Among patients with recent dysvascular LEA, ESRD/HD is not associated with different functional outcomes or LOS in the pre-prosthetic inpatient rehabilitation setting. This suggests that despite added comorbidity that patients with ESRD/HD may still benefit from inpatient rehabilitation to optimize pre-prosthetic function.

The use of activated vitamin D and risks of hospitalization for infection and amputation in incident hemodialysis patients in Taiwan: a nationwide population-based cohort study

BACKGROUND

Hemodialysis patients have a high risk of mortality. The most common causes of death are cardiovascular disease and infection. The potential hazard or benefit associated with vitamin D use and cardiovascular or infection outcome is poorly characterized.

METHODS

We conducted a retrospective observational cohort study by recruiting 52,757 patients older than 20 years from Taiwan National Health Insurance Research Database (NHIRD) who initiated maintenance hemodialysis between 2001 and 2009. Patients who were prescribed activated vitamin D before the 360th day from hemodialysis initiation were defined as vitamin D users. The primary outcome of interest includes occurrence of acute myocardial infarction (AMI), ischemic stroke, lower limb amputation, and hospitalization for infection, respectively, while death events are treated as competing events. We conducted competing risk analysis using subdistribution hazard regression model to estimate subdistribution hazard ratios (SHRs) in relation to various outcomes.

RESULTS

During the median follow-up of 1019 days, the vitamin D users had a lower crude mortality rate, lower incidences of AMI, ischemic stroke, amputation, and hospitalization for infection compared with non-users. Taking into consideration competing events of death, vitamin D users were associated with a lower hazard of lower limb amputation (SHR 0.84 [95% CI, 0.74-0.96]) and hospitalization for infection (SHR 0.90 [95% CI, 0.87-0.94]), but not AMI or ischemic stroke, after adjustment for potential confounders. Subgroup analyses and dose response evaluation both showed a consistent association of activated vitamin D treatment with decreased risk of amputation and infection.

CONCLUSION

The findings suggest that therapeutic activated vitamin D use in hemodialysis patients may be beneficial for decreasing infection events and amputation, of which the latter is a complication of peripheral vascular disease, rather than reducing major atherosclerotic cardiovascular events such as AMI or ischemic stroke.

Incidence of lower extremity amputations among patients with type 1 and type 2 diabetes in the United States from 2010 to 2014

AIM

To compare the incidence of lower extremity amputation (LEA) among patients with type 1 diabetes (T1D) and patients with type 2 diabetes (T2D) with those without diabetes using US commercial claims and to assess the presence of key co-morbidities and precipitating factors at the time of the LEA.

METHODS

Cohorts were defined via IBM MarketScan research databases for beneficiaries with T1D and T2D during 2010-2014. For each T1D and T2D patient, one patient without a prior diabetic claim matched on calendar time, sex and age, was randomly selected. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals.

RESULTS

Among the matched cohorts of 120 129 T1D patients and 1.7 million T2D patients, the incidence of LEA was higher among patients with T1D than patients with T2D, with the most frequent cases being minor LEAs (4.85 and 1.53 per 1000 patient years [PY], respectively), largely toe amputations (4.49 and 1.43 per 1000 PY, respectively). Compared with non-diabetic patients matched on age, sex and calendar time, T1D and T2D patients had more co-morbidities and a higher incidence of LEA (6.02 vs. 0.14 per 1000 PY; aHR, 22.47 [16.42-30.73] and 1.90 vs. 0.23 per 1000 PY; aHR, 4.64 [4.32-4.98]).

CONCLUSIONS

Our data showed a higher incidence of LEA, especially minor LEA, in patients with T1D and T2D compared with those without diabetes, with a greater risk among patients with T1D than patients with T2D. Accounting for known and measurable risk factors for LEA reduced the relative hazard by nearly 50%; the majority of LEA cases were minor LEAs and toe amputations.

Effect of contact with podiatry in a team approach context on diabetic foot ulcer and lower extremity amputation: systematic review and meta-analysis

Multidisciplinary team (MDT) approach has been shown to reduce diabetic foot ulcerations (DFUs) and lower extremity amputations (LEAs), but there is heterogeneity between team members and interventions. Podiatrists have been suggested as “gatekeepers” for the prevention and management of DFUs. The purpose of our study is to review the effect of podiatric interventions in MDTs on DFUs and LEAs. We conducted a systematic review of available literature. Data’s heterogeneity about DFU outcomes made it impossible for us to include it in a meta-analysis, but we identified 12 studies fulfilling inclusion criteria that allowed for them to be included for LEA outcomes. With the exception of one study, all reported favourable outcomes for MDTs that include podiatry. We found statistical significance in favour of an MDT approach including podiatrists for our primary outcome (total LEAs (RR: 0.69, 95% CI 0.54–0.89, I² = 64%, P = 0.002)) and major LEAs (RR: 0.45, 95% CI 0.23–0.90, I² = 67%, P < 0.02). Our systematic review, with a standard search strategy, is the first to specifically address the relevant role of podiatrists and their interventions in an MDT approach for DFU management. Our observations support the literature that MDTs including podiatrists have a positive effect on patient outcomes but there is insufficient evidence that MDTs with podiatry management can reduce the risk of LEAs. Our study highlights the necessity for intervention descriptions and role definition in team approach in daily practice and in published literature.

Potentials, challenges, and limitations of the analysis of administrative data on vascular limb amputations in health care

Although more and more data on lower limb amputations are becoming available by leveraging the widening access to health care administrative databases, the applicability of these data for public health decisions is still limited. Problems can be traced back to methodological issues, how data are generated and to conceptual issues, namely, how data are interpreted in a multidimensional environment. The present review summarised all of the steps from converting the claims data of administrative databases into the analytical data and reviewed the wide array of sources of potential biases in the analysis of such data. The origins of uncertainty of administrative data analysis include uncontrolled confounding due to a lack of clinical data, the left- and right-censored nature of data collection, the non-standardized diagnosis/procedure-based data extraction methods (i.e., numerator/denominator problems) and additional methodological problems associated with temporal and spatial analyses. The existence of these methodological challenges in the administrative data-based analysis should not deter the analysts from using these data as a powerful tool in the armamentarium of clinical research. However, it must be done with caution and a thorough understanding and respect of the methodological limitations. In addition to this requirement, there is a profound need for pursuing further research on methodology and widening the search for other indicators (structural, process or outcome) that allow a deeper insight how the quality of vascular care may be assessed. Effective research using administrative data is based on strong collaboration in three domains, namely expertise in claims data handling and processing, the clinical field, and statistical analysis. The final interpretations of results and the countermeasures on the level of vascular care ought to be grounded on the integrity of research, open discussions and institutionalized mechanisms of science arbitration and honest brokering.

Trends of Nontraumatic Lower-Extremity Amputation in End-Stage Renal Disease and Diabetes: United States, 2000-2015

OBJECTIVE

Nontraumatic lower-extremity amputation (NLEA) is a complication of end-stage renal disease (ESRD) and diabetes. Although recent data show that NLEA rates in the U.S. ESRD population are declining overall, trends in diabetes and diabetes subgroups remain unclear.

RESEARCH DESIGN AND METHODS

We estimated annual rates of NLEA hospitalizations during 2000-2015 among >2 million adults (≥18 years) with ESRD from the U.S. Renal Data System. Age, sex, and race-adjusted NLEA rates were stratified by diabetes status, age, sex, race, and level of amputation (toe, foot, below the knee, and above the knee). Time trends were assessed using Joinpoint regression with annual percent changes (APC) reported.

RESULTS

Among adults with diabetes, NLEA rates declined 43.8% between 2000 and 2013 (from 7.5 to 4.2 per 100 person-years; APC -4.9, P < 0.001) and then stabilized. Among adults without diabetes, rates of total NLEAs declined 25.5% between 2000 and 2013 (from 1.6 to 1.1; APC -3.0, P < 0.001) and then stabilized. These trends appear to be driven by a slowing or stagnation in declines of minor NLEAs (toe and foot) in more recent years, while major NLEAs (above the knee) continue to decline.

CONCLUSIONS

Despite an initial period of decline, this analysis documents a stall in progress in NLEA trends in recent years in a high-risk population with both ESRD and diabetes. Increased attention to preventive foot care in the ESRD population should be considered, particularly for those with diabetes.

Lower Extremity Amputation and Health Care Utilization in the Last Year of Life among Medicare Beneficiaries with ESRD

BACKGROUND

Lower extremity amputation is common among patients with ESRD, and often portends a poor prognosis. However, little is known about end-of-life care among patients with ESRD who undergo amputation.

METHODS

We conducted a mortality follow-back study of Medicare beneficiaries with ESRD who died in 2002 through 2014 to analyze patterns of lower extremity amputation in the last year of life compared with a parallel cohort of beneficiaries without ESRD. We also examined the relationship between amputation and end-of-life care among the patients with ESRD.

RESULTS

Overall, 8% of 754,777 beneficiaries with ESRD underwent at least one lower extremity amputation in their last year of life compared with 1% of 958,412 beneficiaries without ESRD. Adjusted analyses of patients with ESRD showed that those who had undergone lower extremity amputation were substantially more likely than those who had not to have been admitted to-and to have had prolonged stays in-acute and subacute care settings during their final year of life. Amputation was also associated with a greater likelihood of dying in the hospital, dialysis discontinuation before death, and less time receiving hospice services.

CONCLUSIONS

Nearly one in ten patients with ESRD undergoes lower extremity amputation in their last year of life. These patients have prolonged stays in acute and subacute health care settings and appear to have limited access to hospice services. These findings likely signal unmet palliative care needs among seriously ill patients with ESRD who undergo amputation as well as opportunities to improve their care.

Nationwide trends in the epidemiology of diabetic foot complications and lower-extremity amputation over an 8-year period

OBJECTIVE

To study the prevalence and trends of lower extremity complications of diabetes over an 8-year period in a single nation.

RESEARCH DESIGN AND METHODS

Nationwide data for people with type 2 diabetes (T2D) and diabetic foot complications (DFCs) were analyzed over an 8-year period (2007-2014) from National Health Insurance Research Database using the International Classification of Diseases, Ninth Revision disease coding. The DFCs were defined as ulcers, infections, gangrene, and hospitalization for peripheral arterial disease (PAD). Trends of patient characteristics, foot presentation, and the execution of major procedures were studied, including lower-extremity amputations (LEAs).

RESULTS

Along with the T2D population increasing over time, the absolute number of people with DFCs increased by 33.4%, but retained a prevalence of around 2% per year. The annual incident of LEAs decreased from 2.85 to 2.06 per 1000 T2D population (p=0.001) with the major LEA proportion decreasing from 56.2% to 47.4% (p<0.001).The mean age of patients increased from 65.3 to 66.3 years and most of the associated comorbidities of diabetes were increased. For example, end-stage renal disease increased from 4.9% to 7.7% (p=0.008). The incidence of gangrene on presentation decreased from 14.7% to 11.3% (p<0.001) with a concomitant increase in vascular interventions (6.2% to 19.5%, p<0.001).

CONCLUSIONS

DFCs remain a sustained major medical problem. These nationwide long-term data suggest trends toward older people with greater comorbidities such as PAD and renal disease. Nevertheless, promising trends of reducing gangrene on presentation paired with increases in vascular interventions support continued vigilance and rapid, coordinated interdisciplinary diabetic foot care.

Preventing and treating kidney disease in patients with type 2 diabetes

INTRODUCTION

Chronic kidney disease (CKD) represents a huge burden in patients with type 2 diabetes (T2DM). This review therefore has the aim of assessing the add-on value of new glucose-lowering agents compared or combined with inhibitors of the renin angiotensin aldosterone system (RAAS) on renal outcomes in T2DM patients.

AREAS COVERED

This article first summarizes the results reported with RAAS inhibitors, mainstay of nephroprotection in T2DM with albuminuria. Second, it describes the positive results with glucagon-like peptide-1 receptor agonists (GLP-1RAs) and, even more impressive, sodium-glucose cotransporter type 2 inhibitors (SGLT2is). Third, besides the potential of combined therapies, it briefly considers some new approaches currently in development.

EXPERT OPINION

RAAS inhibitors exert renoprotective effects beyond their blood pressure lowering effects while SGLT2is, and possibly GLP-1RAs, exert nephroprotection independently of their glucose-lowering activity. These effects were demonstrated not only on surrogate endpoints such as albuminuria and estimated glomerular filtration rate decline, but also on hard endpoints, including progression to end-stage renal disease requiring replacement therapy. The underlying mechanisms are different and potentially complementary on glomerular hemodynamics, arguing for combined therapies. Nevertheless, there is still room for new emerging drugs to tackle CKD in T2DM.