Amputation Risk in Patients with Diabetes Mellitus and Peripheral Artery Disease Using Statewide Data

Editor's Choice - Prognostic Factors and Models to Predict Mortality Outcomes in Patients with Peripheral Arterial Disease: A Systematic Review

OBJECTIVE

Predicting adverse outcomes in patients with peripheral arterial disease (PAD) is a complex task owing to the heterogeneity in patient and disease characteristics. This systematic review aimed to identify prognostic factors and prognostic models to predict mortality outcomes in patients with PAD Fontaine stage I - III or Rutherford category 0 - 4.

DATA SOURCES

PubMed, Embase, and Cochrane Database of Systematic Reviews were searched to identify studies examining individual prognostic factors or studies aiming to develop or validate a prognostic model for mortality outcomes in patients with PAD.

REVIEW METHODS

Information on study design, patient population, prognostic factors, and prognostic model characteristics was extracted, and risk of bias was evaluated.

RESULTS

Sixty nine studies investigated prognostic factors for mortality outcomes in PAD. Over 80 single prognostic factors were identified, with age as a predictor of death in most of the studies. Other common factors included sex, diabetes, and smoking status. Six studies had low risk of bias in all domains, and the remainder had an unclear or high risk of bias in at least one domain. Eight studies developed or validated a prognostic model. All models included age in their primary model, but not sex. All studies had similar discrimination levels of > 70%. Five of the studies on prognostic models had an overall high risk of bias, whereas two studies had an overall unclear risk of bias.

CONCLUSION

This systematic review shows that a large number of prognostic studies have been published, with heterogeneity in patient populations, outcomes, and risk of bias. Factors such as sex, age, diabetes, hypertension, and smoking are significant in predicting mortality risk among patients with PAD Fontaine stage I - III or Rutherford category 0 - 4.

Peripheral neuropathy prevalence and effect on mobility 12 months after prosthesis prescription among individuals with dysvascular lower extremity amputation

OBJECTIVE

To determine the prevalence of peripheral neuropathy (PN) and its effect on mobility in patients who were prescribed a lower limb prosthesis (LLP) after an incident dysvascular transtibial (TT) or transfemoral (TF) lower extremity amputation (LEA). We also sought to determine if the effect of PN on mobility was modified by amputation level or depression.

DESIGN

Participants were identified retrospectively through the Veterans Affairs (VA) Corporate Data Warehouse (CDW) from March 1, 2018, to November 30, 2020, then were contacted prospectively to obtain their self-reported mobility. Multiple logistic regression was used to control for potential confounders and identify potential effect modifiers.

SETTING

The VA CDW, the National Prosthetics Patient Database, participant mailings and phone calls.

PARTICIPANTS

Three hundred fifty-seven individuals who underwent a TT or TF amputation due to diabetes and/or peripheral arterial disease and were fitted with a qualifying LLP.

INTERVENTIONS

Not applicable.

MAIN OUTCOMES MEASURES

The Locomotor Capabilities Index basic and advanced mobility subscale scores.

RESULTS

Two-hundred thirty seven participants (66%) had a diagnosis of PN prior to prosthesis prescription. The detrimental effect of PN on achieving basic and advanced mobility was significant after adjusting for potential confounding factors (adjusted odds ratio [aOR], 0.53; 95% confidence interval [CI], 0.30-0.94; p = .03 and aOR, 0.43; 95% CI, 0.24-0.77; p = .005, respectively). The detrimental effect of PN was more pronounced in patients with depression, especially for advanced mobility (aOR, 0.36; 95% CI, 0.14-0.95; p = .04) versus no depression (aOR, 0.53; 95% CI, 0.27-1.0; p = .07).

CONCLUSIONS

PN is common in patients who have undergone an LEA due to diabetes and/or vascular disease and patients with this diagnosis should be carefully evaluated. Targeted rehabilitation programs to mitigate its potential detrimental effects on mobility are important and should specifically include mental health assessment and treatment.

The Effect of Limb Salvage Efforts in Different Age Groups: Relationships Between Major and Minor Amputations

"Limb salvage" efforts, such as performing minor amputations before infections spread proximally from the foot to decrease major lower extremity amputation, are an important part of healthcare today. It is unclear whether these efforts are preventing the number of major amputations and improving patients' quality of life and the cost-effectiveness of the U.S. healthcare system. Rates of non-traumatic lower extremity amputation (NLEA) among patients with diabetes decreased in the early 2000s but rebounded in the 2010s. We analyzed the proportion of major amputations and differences in amputation rates between age groups in Texas. Patient data was extracted from the Texas Hospital Discharge Data Public Use Data File. Population estimates were obtained from the Texas Population Estimates Program from 2011 to 2015 and from intercensal estimates provided by the U.S. Census Bureau from 2006 to 2010. Raw numbers of minor, major, and all NLEA surgeries and the ratio of major amputations to total amputations per year were reported for each age group. Poisson regression and Joinpoint analyses were performed to capture these changes in trends. Rates of amputations increased, with significant decreasing relative prevalence of major amputations. Patients aged 45 to 64 with diabetes are likely driving these increases. Rates of lower extremity amputation in patients with diabetes increased from 2009 to 2015. This holds for all and minor amputations. In contrast, the ratio of major to all amputations decreased from 2010. Utilization of major and minor amputation differs between age groups, remaining stable in the youngest subjects, with minor amputation rates increasing in those aged 45 to 64.

Real-World Incidence of Adverse Clinical Outcomes Among People With Coronary Artery Disease and/or Peripheral Artery Disease in Relation to Vascular Risk in the United States

Presence of polyvascular disease, diabetes, heart failure, or renal insufficiency in patients with chronic coronary artery disease (CAD) and peripheral artery disease (PAD) are associated with increased risks of adverse events, including major adverse cardiovascular events (MACEs) and major adverse limb events (MALEs). In this retrospective observational study using administrative claims data from Optum's deidentified Clinformatics Data Mart Database from January 2016 to September 2021, we described the incidence rates of MACEs, MALEs, and major thrombotic vascular events in patients with CAD or PAD stratified by the presence of risk factors (i.e., polyvascular disease, diabetes, heart failure, or renal insufficiency). A total of 1,435,241 patients (77% CAD and 34% PAD) met the inclusion and exclusion criteria. Patients with 0 risk factors were deemed the low-risk group (47%; n = 681,333) and patients with ≥1 risk factor were deemed the high-risk group (53%; n = 753,908). The mean age was 71.8 and 73.6 years, and 42% and 44% were female in the low- and high-risk groups, respectively. Compared with the low-risk group, the high-risk group had a 72% higher hazard of developing MACEs (adjusted hazard ratio 1.72, 95% confidence interval 1.70 to 1.74), 82% higher hazard of developing major thrombotic vascular events (1.82, 1.80 to 1.84), and 146% higher hazard of developing MALEs (2.46, 2.39 to 2.53) (all p <0.001). In conclusion, in patients with CAD or PAD, the presence of 1 or more risk factors was associated with higher risks of MACEs, MALEs, and major thrombotic vascular events, underscoring the need to improve management of underlying diseases in this population.

The correlation between transcutaneous oxygen pressure (TcPO2 ) and forward-looking infrared (FLIR) thermography in the evaluation of lower extremity perfusion according to angiosome

The increased peripheral arterial disease (PAD) incidence associated with aging and increased incidence of cardiovascular conditions underscores the significance of assessing lower limb perfusion. This study aims to report on the correlation and utility of two novel non-invasive instruments: transcutaneous oxygen pressure (TcPO2 ) and forward-looking infrared (FLIR) thermography. A total of 68 patients diagnosed with diabetic foot ulcer and PAD who underwent vascular studies at a single institution between March 2022 and March 2023 were included. Cases with revascularization indications were treated by a cardiologist. Following the procedure, ambient TcPO2 and FLIR thermography were recorded on postoperative days 1, 7, 14, 21 and 28. In impaired limbs, TcPO2 was 12.3 ± 2 mmHg and FLIR thermography was 28.7 ± 0.9°C. TcPO2 (p = 0.002), FLIR thermography (p = 0.015) and ankle-brachial index (p = 0.047) values significantly reduced with greater vascular obstruction severity. Revascularization (n = 39) significantly improved TcPO2 (12.5 ± 1.7 to 19.1 ± 2.2 mmHg, p = 0.011) and FLIR (28.8 ± 1.8 to 32.6 ± 1.6°C; p = 0.018), especially in severe impaired angiosomes. TcPO2 significantly increased immediately post-procedure, then gradually, whereas the FLIR thermography values plateaued from day 1 to 28 post-procedure. In conclusion, FLIR thermography is a viable non-invasive tool for evaluating lower limb perfusion based on angiosomes, comparable with TcPO2 .

Inflammatory Markers Used as Predictors of Subclinical Atherosclerosis in Patients with Diabetic Polyneuropathy

BACKGROUND

peripheral arterial disease (PAD) is identified late in diabetic patients because, in the majority of cases, it is associated with diabetic peripheral neuropathy, resulting in little or no symptoms, or symptoms that are completely neglected.

METHODS

In this study were enrolled all patients over 18 years of age, with diabetes mellitus type II for more than a year with poor glycemic control, diagnosed with diabetic polyneuropathy admitted to the Diabetology Department, Emergency County Hospital of Targu Mures, Romania between January 2020 and March 2023. We divided the patients into two groups, based on the presence or absence of subclinical atherosclerosis in the lower limb, named "SA" and "non-SA".

RESULTS

Patients in the SA group were older (p = 0.01) and had a higher incidence of IHD (p = 0.03), history of MI (p = 0.02), and diabetic nephropathy (p = 0.01). Moreover, patients with subclinical atherosclerosis had a higher BMI (p < 0.0001) and a longer duration of diabetes (p < 0.0001). Among all patients, the systemic inflammatory markers, MLR (r = 0.331, p < 0.001), NLR (r = 0.517, p < 0.001), PLR (r = 0.296, p < 0.001), SII (r = 0.413, p < 0.001), as well as BMI (r = 0.241, p < 0.001) and HbA1C (r = 0.489, p < 0.001), demonstrated a strong positive correlation with the diabetes duration. The multivariate logistic regression analysis showed that older patients (OR: 2.58, p < 0.001), the male gender (OR: 2.30, p = 0.006), a higher baseline levels of BMI (OR: 7.71, p < 0.001), and the duration of diabetes (OR: 8.65, p < 0.001) are predictors of subclinical atherosclerosis in DN patients. Additionally, the high baseline levels of all systemic inflammatory markers (for all: p < 0.001) and poor diabetes management (OR: 10.4, p < 0.001 for HbA1C; OR: 10.78, p < 0.001 for admission glucose) are independent predictors of SA.

CONCLUSIONS

the inflammatory markers, NLR, MLR, PLR, and SII, being cheap and easy to collect in routine medical practice from the standard blood tests, could be an important step in predicting vascular outcomes in diabetic patients and the disease's progression, playing a key role in follow-up visits in type-2 diabetic patients and PAD patients.

Apelin prevents diabetes-induced poor collateral vessel formation and blood flow reperfusion in ischemic limb

Introduction

Peripheral arterial disease (PAD) is a major risk factor for lower-extremity amputation in diabetic patients. Unfortunately, previous clinical studies investigating therapeutic angiogenesis using the vascular endothelial growth factor (VEGF) have shown disappointing results in diabetic patients, which evokes the necessity for novel therapeutic agents. The apelinergic system (APJ receptor/apelin) is highly upregulated under hypoxic condition and acts as an activator of angiogenesis. Apelin treatment improves revascularization in nondiabetic models of ischemia, however, its role on angiogenesis in diabetic conditions remains poorly investigated. This study explored the impact of Pyr-apelin-13 in endothelial cell function and diabetic mouse model of hindlimb ischemia.

Methods

Nondiabetic and diabetic mice underwent femoral artery ligation to induce limb ischemia. Diabetic mice were implanted subcutaneously with osmotic pumps delivering Pyr-apelin-13 for 28 days. Blood flow reperfusion was measured for 4 weeks post-surgery and exercise willingness was assessed with voluntary wheels. In vitro, bovine aortic endothelial cells (BAECs) were exposed to normal (NG) or high glucose (HG) levels and hypoxia. Cell migration, proliferation and tube formation assays were performed following either VEGF or Pyr-apelin-13 stimulation.

Results and Discussion

Following limb ischemia, blood flow reperfusion, functional recovery of the limb and vascular density were improved in diabetic mice receiving Pyr-apelin-13 compared to untreated diabetic mice. In cultured BAECs, exposure to HG concentrations and hypoxia reduced VEGF proangiogenic actions, whereas apelin proangiogenic effects remained unaltered. Pyr-apelin-13 induced its proangiogenic actions through Akt/AMPK/eNOS and RhoA/ROCK signaling pathways under both NG or HG concentrations and hypoxia exposure. Our results identified the apelinergic system as a potential therapeutic target for angiogenic therapy in diabetic patients with PAD.

Trends of Concomitant Diabetes and Peripheral Artery Disease and Lower Extremity Amputation in US Medicare Patients, 2007 to 2019

BACKGROUND

Previous studies demonstrate geographic and racial/ethnic variation in diagnosis and complications of diabetes and peripheral artery disease (PAD). However, recent trends for patients diagnosed with both PAD and diabetes are lacking. We assessed the period prevalence of concurrent diabetes and PAD across the United States from 2007 to 2019 and regional and racial/ethnic variation in amputations among Medicare patients.

METHODS

Using Medicare claims from 2007 to 2019, we identified patients with both diabetes and PAD. We calculated period prevalence of concomitant diabetes and PAD and incident cases of diabetes and PAD for every year. Patients were followed to identify amputations, and results were stratified by race/ethnicity and hospital referral region.

RESULTS

9 410 785 patients with diabetes and PAD were identified (mean age, 72.8 [SD, 10.94] years; 58.6% women, 74.7% White, 13.2% Black, 7.3% Hispanic, 2.8% Asian/API, and 0.6% Native American). Period prevalence of diabetes and PAD was 23 per 1000 beneficiaries. We observed a 33% relative decrease in annual new diagnoses throughout the study. All racial/ethnic groups experienced a similar decline in new diagnoses. Black and Hispanic patients had on average a 50% greater rate of disease compared with White patients. One- and 5-year amputation rates remained stable at ≈1.5% and 3%, respectively. Native American, Black, and Hispanic patients were at greater risk of amputation compared with White patients at 1- and 5-year time points (5-year rate ratio range, 1.22-3.17). Across US regions, we observed differential amputation rates, with an inverse relationship between the prevalence of concomitant diabetes and PAD and overall amputation rates.

CONCLUSIONS

Significant regional and racial/ethnic variation exists in the incidence of concomitant diabetes and PAD among Medicare patients. Black patients in areas with the lowest rates of PAD and diabetes are at disproportionally higher risk for amputation. Furthermore, areas with higher prevalence of PAD and diabetes have the lowest rates of amputation.

The outcomes of lower extremity revascularization: What role do race, ethnicity, and socioeconomic status play?

Lower extremity peripheral artery disease and the resultant complications disproportionately affect underrepresented racial and ethnic minority groups, as well as those with low socioeconomic status (SES). Revascularization, including both open surgical and endovascular techniques, is a mainstay of therapy for symptomatic peripheral artery disease; it is required to maximize limb salvage in chronic limb-threatening ischemia and used to improve function and quality of life in patients with claudication. The outcomes of lower extremity revascularization in Black and Hispanic patients, as well as patients with low SES, are not widely known and this knowledge gap formed the basis for this review. The preponderance of evidence suggests that Black, Hispanic, and low-SES patients have inferior limb-related outcomes after revascularization compared with White patients. Based solely on the limited published evidence in the revascularization literature, the specific reasons for these disparities are not clear. The high prevalence of comorbidities and risks factors, as well as the advanced presentation of peripheral artery disease in Black, Hispanic, and low-SES patients, appear to contribute to the inferior limb outcomes post revascularization seen in these groups, but do not account for all of the disparities. Undoubtedly, a complex interplay of social determinants underlies these disparities in care and outcomes at individual, community, and societal levels. Additional understanding of the underpinnings and mechanisms of inferior outcomes in these populations in the specific context of lower extremity revascularization is needed, as this would allow us to identify targets for intervention to improve post-revascularization outcomes in these at-risk populations.

The influence of diabetes on temporal trends in lower extremity revascularisation and amputation for peripheral artery disease: A population-based repeated cross-sectional analysis

AIM/HYPOTHESIS

To describe the influence of diabetes on temporal changes in rates of lower extremity revascularisation and amputation for peripheral artery disease (PAD) in Ontario, Canada.

METHODS

In this population-based repeated cross-sectional study, we calculated annual rates of lower extremity revascularisation (open or endovascular) and amputation (toe, foot or leg) related to PAD among Ontario residents aged ≥40 years between 2002 and 2019. Annual rate ratios (relative to 2002) adjusted for changes in diabetes prevalence alone, as well as fully adjusted for changes in demographics, diabetes and other comorbidities, were estimated using generalized estimating equation models to model population-level effects while accounting for correlation within units of observation.

RESULTS

Compared with 2002, the Ontario population in 2019 exhibited a significantly higher prevalence of diabetes (18% vs. 10%). Between 2002 and 2019, the crude rate of revascularisation increased from 75.1 to 90.7/100,000 person-years (unadjusted RR = 1.10, 95% CI = 1.07-1.13). However, after adjustment, there was no longer an increase in the rate of revascularisation (diabetes-adjusted RR = 0.98, 95% CI = 0.96-1.01, fully-adjusted RR = 0.94, 95% CI = 0.91-0.96). The crude rate of amputation decreased from 2002 to 2019 from 49.5 to 45.4/100,000 person-years (unadjusted RR = 0.78, 95% CI = 0.75-0.81), but was more pronounced after adjustment (diabetes-adjusted RR = 0.62, 95% CI = 0.60-0.64; fully-adjusted RR = 0.58, 95% CI = 0.56-0.60).

CONCLUSIONS/INTERPRETATION

Diabetes prevalence rates strongly influenced rates of revascularisation and amputation related to PAD. A decrease in amputations related to PAD over time was attenuated by rising diabetes prevalence rates.

Cross Talks between Oxidative Stress, Inflammation and Epigenetics in Diabetic Retinopathy

Diabetic retinopathy, one of the most devastating complications of diabetes, is a multifactorial progressing disease with a very complex etiology. Although many metabolic, molecular, functional and structural changes have been identified in the retina and its vasculature, the exact molecular mechanism of its pathogenesis still remains elusive. Sustained high-circulating glucose increases oxidative stress in the retina and also activates the inflammatory cascade. Free radicals increase inflammatory mediators, and inflammation can increase production of free radicals, suggesting a positive loop between them. In addition, diabetes also facilitates many epigenetic modifications that can influence transcription of a gene without changing the DNA sequence. Several genes associated with oxidative stress and inflammation in the pathogenesis of diabetic retinopathy are also influenced by epigenetic modifications. This review discusses cross-talks between oxidative stress, inflammation and epigenetics in diabetic retinopathy. Since epigenetic changes are influenced by external factors such as environment and lifestyle, and they can also be reversed, this opens up possibilities for new strategies to inhibit the development/progression of this sight-threatening disease.

Global estimates of diabetes-related amputations incidence in 2010-2020: A systematic review and meta-analysis

AIMS/HYPOTHESIS

This study sought to provide up-to-date pooled global estimates of diabetes-related amputation incidence from 2010 to 2020.

METHODS

Embase and Medline databases were searched for studies reporting the incidence rate (IR) of diabetes-related amputations from 2010 to 2020. IR estimates of diabetes-related amputations with associated 95% confidence interval (CI) per 100,000 individuals with diabetes were calculated.

RESULTS

23 studies were included, reporting 505,390 diabetes-related lower extremity amputations. IR of minor amputations was 139.97 (95% CI 88.18-222.16) per 100,000 individuals with diabetes, among patients with type 1 diabetes was 148.59 (95% CI 65.00-339.68) and in type 2 diabetes was 75.53 (95% CI 29.94-190.54). IR of major amputations was 94.82 (95% CI 56.62-158.80) per 100,000 individuals with diabetes, among patients with type 1 diabetes was 100.76 (95% CI 53.71-189.01) and among type 2 diabetes was 40.58 (95% CI 11.03-149.28). There were 83.84 annual amputations (95% CI 41.67-168.65) per 100,000 women with diabetes and 178.04 (95% CI 81.16-390.55) per 100,000 men.

CONCLUSIONS

Globally, annual incidence of diabetes-related amputations from 2010 to 2020 has shown to disproportionately affect men and individuals with type 1 diabetes mellitus, although its incidence is not uniform across countries.

Temporal trends in patients with peripheral artery disease influenced by diabetes mellitus in Germany

INTRODUCTION

In patients with peripheral artery disease (PAD) the presence of diabetes mellitus (DM) is associated with higher morbidity and mortality. Because huge efforts are made to improve medical care of patients with DM including chronic disease programs, the aim of the present study was to investigate temporal trends regarding the clinical burden of DM on PAD patients within a 15-year observational period.

METHODS

We analyzed all patients hospitalized because of PAD between 2005 and 2019 in Germany stratified regarding DM.

RESULTS

Overall, 2 654 871 hospitalizations of PAD patients (865 823 with DM) were included. Hospitalizations based on PAD inclined from 142 778 in 2005 to 190 135 in 2019 (β 3956 per year; 95% confidence interval [CI] 3034-4878, p < .001) with simultaneous increase of hospitalizations of PAD patients with DM (2005: 41609 (29.1%) versus 2019: 65 302 (34.3%); β 2019 per year [95% CI 1593-2446], p < .001). Amputation rates (β -0.42 [95% CI -0.44 to -0.40]; p < .001) as well as in-hospital case-fatality rate (2005: 4.7%, 2019: 2.8%; β -0.64 [95% CI -0.69 to -0.59]; p < .001) decreased in diabetic PAD patients during the observational time. In spite of improved morbidity and mortality in the last years of the observational period, patients with DM still suffered from an increased risk for morbidity and mortality during the observational period compared to nondiabetic PAD patients.

CONCLUSIONS

Despite the progress in DM treatments, DM still was associated with an unfavorable clinical patient profile and remained a substantial risk factor for morbidity and mortality in hospitalized patients with PAD and DM in Germany between 2005 and 2019.

The incidence and trend of geriatric amputations in Taiwan from 1996 to 2013

BACKGROUND

There has been a reported reduction in the incidence of amputation, but it is unclear whether the number of amputations has decreased in the elderly, a cohort that typically has the largest proportion of amputees.

OBJECTIVES

To investigate the incidence proportion and time trends of amputation in patients aged ≥ 65 years in Taiwan.

STUDY DESIGN

A retrospective cohort study from a large national database.

METHODS

The records of patients who underwent an amputation were collected from a nationally representative sample of 1,000,000 enrollees of Taiwan's National Health Insurance program during 1996-2013. The patients were divided into four age groups: ≤64, 65-74, 75-84, and ≥85 years. Joinpoint regression was performed with adjustment for age and sex to identify changes in incidence proportion by year.

RESULTS

During the 18 years, the incidence of upper and lower limb amputation decreased significantly in the total population, with the average annual percentage change (AAPC) of -6.1 and -1.8, respectively. However, in the elderly population over 65 years, the incidence did not decrease significantly for upper minor amputation, lower minor amputation, and major amputation with the AAPC of -1.1, -0.1, and -0.4, respectively. Although not significant, the incidence of major and minor lower limb amputation in the population over 85 years old showed an increasing trend, with the AAPC of 1.2 and 3.2, respectively.

CONCLUSION

During the study period, although the incidence of amputation of the overall population decreased in Taiwan, this trend was not simultaneously observed in the elderly and hence, it should not be ignored.

Non-Hispanic Black and Hispanic Patients Have Worse Outcomes Than White Patients Within Similar Stages of Peripheral Artery Disease

Background Racial and ethnic disparities in outcomes following lower limb revascularization for peripheral artery disease have been ascribed to disease severity at presentation for surgery. Methods and Results We calculated 1-year risk of major adverse limb events (MALEs), major amputation, and death for patients undergoing elective revascularization for claudication or chronic limb-threatening ischemia in the Vascular Quality Initiative data (2011-2018). We report hazard ratios according to race and ethnicity using Cox (death) or Fine and Gray subdistribution hazards models (MALE and major amputation, treating death as a competing event), adjusted for patient, treatment, and anatomic factors associated with disease severity. Among 88 599 patients (age, 69 years; 37% women), 1-year risk of MALE (major amputation and death) was 12.8% (95% CI, 12.5-13.0) in 67 651 White patients, 16.5% (95% CI, 5.8-7.8) in 15 442 Black patients, and 17.2% (95% CI, 5.6-6.9) in 5506 Hispanic patients. Compared with White patients, we observed an increased hazard of poor limb outcomes among Black (MALE: 1.17; 95% CI, 1.12-1.22; amputation: 1.52; 95% CI, 1.39-1.65) and Hispanic (MALE: 1.22; 95% CI, 1.14-1.31; amputation: 1.45; 95% CI, 1.28-1.64) patients. However, Black and Hispanic patients had a hazard of death of 0.85 (95% CI, 0.79-0.91) and 0.71 (95% CI, 0.63-0.79) times the hazard among White patients, respectively. Worse limb outcomes were observed among Black and Hispanic patients across subcohorts of claudication and chronic limb-threatening ischemia. Conclusions Black and Hispanic patients undergoing infrainguinal revascularization for chronic limb-threatening ischemia and claudication had worse limb outcomes compared with White patients, even with similar disease severity at presentation. Additional investigation aimed at eliminating disparate limb outcomes is needed.

Trends of limb amputation considering type, level, sex and age in Saskatchewan, Canada 2006-2019: an in-depth assessment

BACKGROUND

Most epidemiologic reports focus on lower extremity amputation (LEA) caused specifically by diabetes mellitus. However, narrowing scope disregards the impact of other causes and types of limb amputation (LA) diminishing the true incidence and societal burden. We explored the rates of LEA and upper extremity amputation (UEA) by level of amputation, sex and age over 14 years in Saskatchewan, Canada.

METHODS

We calculated the differential impact of amputation type (LEA or UEA) and level (major or minor) of LA using retrospective linked hospital discharge data and demographic characteristics of all LA performed in Saskatchewan and resident population between 2006 and 2019. Rates were calculated from total yearly cases per yearly Saskatchewan resident population. Joinpoint regression was employed to quantify annual percentage change (APC) and average annual percent change (AAPC). Negative binomial regression was performed to determine if LA rates differed over time based on sex and age.

RESULTS

Incidence of LEA (31.86 ± 2.85 per 100,000) predominated over UEA (5.84 ± 0.49 per 100,000) over the 14-year study period. The overall LEA rate did not change over the study period (AAPC -0.5 [95% CI - 3.8 to 3.0]) but fluctuations were identified. From 2008 to 2017 LEA rates increased (APC 3.15 [95% CI 1.1 to 5.2]) countered by two statistically insignificant periods of decline (2006-2008 and 2017-2019). From 2006 to 2019 the rate of minor LEA steadily increased (AAPC 3.9 [95% CI 2.4 to 5.4]) while major LEA decreased (AAPC -0.6 [95% CI - 2.1 to 5.4]). Fluctuations in the overall LEA rate nearly corresponded with fluctuations in major LEA with one period of rising rates from 2010 to 2017 (APC 4.2 [95% CI 0.9 to 7.6]) countered by two periods of decline 2006-2010 (APC -11.14 [95% CI - 16.4 to - 5.6]) and 2017-2019 (APC -19.49 [95% CI - 33.5 to - 2.5]). Overall UEA and minor UEA rates remained stable from 2006 to 2019 with too few major UEA performed for in-depth analysis. Males were twice as likely to undergo LA than females (RR = 2.2 [95% CI 1.99-2.51]) with no change in rate over the study period. Persons aged 50-74 years and 75+ years were respectively 5.9 (RR = 5.92 [95% Cl 5.39-6.51]) and 10.6 (RR = 10.58 [95% Cl 9.26-12.08]) times more likely to undergo LA than those aged 0-49 years. LA rate increased with increasing age over the study period.

CONCLUSION

The rise in the rate of minor LEA with simultaneous decline in the rate of major LEA concomitant with the rise in age of patients experiencing LA may reflect a paradigm shift in the management of diseases that lead to LEA. Further, this shift may alter demand for orthotic versus prosthetic intervention. A more granular look into the data is warranted to determine if performing minor LA diminishes the need for major LA.

Mortality, Cardiovascular and Limb Events in Patients With Symptomatic Lower Extremity Artery Disease and Diabetes

The aim of this study was to compare the prognosis of patients according to diabetes status, during a 1-year follow-up after hospital admission for lower extremity artery disease, in the prospective COPART (COhorte de Patients ARTériopathes) registry. Inclusion criteria were intermittent claudication, ischemic rest pain, tissue loss, or acute limb ischemia, with radiological and hemodynamic confirmation. Among 2494 patients, 1235 (49.5%) had diabetes. Incidence rates for major adverse cardiovascular events (MACE) were 18.0/100 person-years (95% confidence interval [CI], 15.4-21.0) for the diabetes group and 11.1/100 person-years (95% CI, 9.2-13.4) for the non-diabetes group. Incidence rates of all-cause mortality were 29.8/100 person-years (95% CI, 26.5-33.4) for the diabetes group and 19.7/100 person-years (95% CI, 17.2-22.7) for the non-diabetes group. Incidence rates of major limb amputation were 24.2/100 person-years (95% CI, 21.1-27.8) for the diabetes group and 11.6/100 person-years (95% CI, 9.6-14.0) for the non-diabetes group. Diabetes was associated with MACE, adjusted hazard ratio 1.60 (95% CI, 1.16-2.22), and all-cause mortality, unadjusted HR 1.49 (95% CI, 1.24-1.78). In the multivariate analysis, diabetes was no longer associated with major amputation, adjusted HR 1.15 (95% CI, .87-1.51). Patients hospitalized for LEAD with diabetes had a higher risk of MACE than those without diabetes.

Infrared Thermography as a Diagnostic Tool for the Assessment of Patients with Symptomatic Peripheral Arterial Disease Undergoing Infrafemoral Endovascular Revascularisations

Aim: The aim of this study was to evaluate the utility and reliability of temperature foot changes measured by infrared thermography (IRT) for the evaluation of patients with atherosclerotic peripheral arterial disease (PAD) before and after endovascular revascularisation. Methods: This is an observational prospective study carried out on symptomatic PAD patients. Evaluations consisted of a clinical examination, duplex scan with ankle–brachial index calculation (ABI) and IRT measurements with infrared camera FLIR-ONE connected to a smartphone with android technology. Locations on the foot sampled with IRT were the anterior tibial, pedal, posterior and arcuate arteries. Results obtained with IRT on the symptomatic foot were compared to the contralateral foot and with the ABI values obtained bilaterally before and 24 h after revascularisation. Results: Within one year, 40 patients were enrolled, among whom 87,5% suffered from critical limb ischaemia. In three patients, it was impossible to obtain ABI measurements because of ulcerations on the limb. Skin temperature changes obtained by IRT between the symptomatic limb and the contralateral limb had a mean difference of 1.7 °C (range: 1.1–2.2 °C), p < 0.001. There was a positive correlation between ABI and temperature values of the limb needed for treatment before revascularisation (p = 0.025; r = 0.36) and after revascularisation (p = 0.024, r = 0.31). The technical success rate was 100% in all cases, achieving a significant increase in temperature at all points of the foot analysed, with a median change of 2 °C (p < 0.001). Conclusion: IRT is a safe, reliable and simple application. It could be a valuable tool for the assessment of the clinical presentation and severity of foot blood perfusion in symptomatic PAD patients and the evaluation of the technical success of endovascular revascularisation. IRT might have a role in follow-up of revascularisation procedures.

Incidence and trends of limb amputation in first nations and general population in Saskatchewan, 2006-2019

BACKGROUND

There is conflicting evidence whether limb amputation (LA) disproportionately affects indigenous populations. To better understand this disparity, we compared the LA incidence rate between First Nations persons registered under the Indian Act of Canada (RI) and the general population (GP) in Saskatchewan.

METHODS

We used Saskatchewan's retrospective administrative data containing hospital discharge LA cases, demographic characteristics (age and sex), and residents population reported in the database stratified by RI and GP from 2006-2019. The LA cases for each stratified group were first disaggregated into three broad categories: overall LA (all reported LA), primary LA (first reported LA), and subsequent LA (revision or contralateral LA), with each category further split into the level of amputation defined as major amputation (through/above the ankle/wrist joint) and minor amputation (below the ankle/wrist joint). LA rates were calculated using LA cases as the numerator and resident population as the denominator. Joinpoint and negative binomial regressions were performed to explore the trends further.

RESULTS

Overall, there were 1347 RI and 4520 GP LA cases reported in Saskatchewan from 2006-2019. Primary LA made up approximately 64.5% (869) of RI and 74.5% (3369) of GP cases, while subsequent LA constituted 35.5% (478) of RI and 25.5% (1151) of GP cases. The average age-adjusted LA rate was 153.9 ± 17.3 per 100,000 in the RI cohort and 31.1 ± 2.3 per 100,000 in the GP cohort. Overall and primary LA rates for the GP Group declined 0.7% and 1.0%, while subsequent LA increased 0.1%. An increased LA rate for all categories (overall 4.9%, primary 5.1%, and subsequent 4.6%) was identified in the RI group. Overall, minor and major LA increased by 6.2% and 3.3%, respectively, in the RI group compared to a 0.8% rise in minor LA and a 6.3% decline in major LA in the GP group. RI females and males were 1.98-1.66 times higher risk of LA than their GP counterparts likewise, RI aged 0-49 years and 50+ years were 2.04-5.33 times higher risk of LA than their GP cohort. Diabetes mellitus (DM) was the most prevalent amputation predisposing factor in both groups with 81.5% of RI and 54.1% of GP diagnosed with DM. Also, the highest proportion of LA was found in the lowest income quintile for both groups (68.7% for RI and 45.3% for GP).

CONCLUSION

Saskatchewan's indigenous individuals, specifically First Nations persons registered under the Indian Act of Canada, experience LA at a higher rate than the general population. This disparity exists for all variables examined, including overall, primary, and subsequent LA rates, level of amputation, sex, and age. Amplification of the disparities will continue if the rates of change maintain their current trajectories. These results underscore the need for a better understanding of underlying causes to develop a targeted intervention in these groups.

Reducing Nontraumatic Lower-Extremity Amputations by 20% by 2030: Time to Get to Our Feet: A Policy Statement From the American Heart Association

Nontraumatic lower-extremity amputation is a devastating complication of peripheral artery disease (PAD) with a high mortality and medical expenditure. There are ≈150 000 nontraumatic leg amputations every year in the United States, and most cases occur in patients with diabetes. Among patients with diabetes, after an ≈40% decline between 2000 and 2009, the amputation rate increased by 50% from 2009 to 2015. A number of evidence-based diagnostic and therapeutic approaches for PAD can reduce amputation risk. However, their implementation and adherence are suboptimal. Some racial/ethnic groups have an elevated risk of PAD but less access to high-quality vascular care, leading to increased rates of amputation. To stop, and indeed reverse, the increasing trends of amputation, actionable policies that will reduce the incidence of critical limb ischemia and enhance delivery of optimal care are needed. This statement describes the impact of amputation on patients and society, summarizes medical approaches to identify PAD and prevent its progression, and proposes policy solutions to prevent limb amputation. Among the actions recommended are improving public awareness of PAD and greater use of effective PAD management strategies (eg, smoking cessation, use of statins, and foot monitoring/care in patients with diabetes). To facilitate the implementation of these recommendations, we propose several regulatory/legislative and organizational/institutional policies such as adoption of quality measures for PAD care; affordable prevention, diagnosis, and management; regulation of tobacco products; clinical decision support for PAD care; professional education; and dedicated funding opportunities to support PAD research. If these recommendations and proposed policies are implemented, we should be able to achieve the goal of reducing the rate of nontraumatic lower-extremity amputations by 20% by 2030.

The interrelationship between diabetes mellitus and peripheral arterial disease - a systematic review

This systematic review examined the interrelationship between concomitant diabetes mellitus (DM) and peripheral arterial disease (PAD). The objective was to determine differences in the prevalence as well as in the outcomes in diabetic vs. non-diabetic PAD patients. The current review followed a study protocol that was published online in German in 2017. The search included societal practice guidelines, consensus statements, systematic reviews, meta-analyses, and observational studies published from 2007 to 2020 reporting symptomatic PAD and concomitant DM in patients undergoing invasive open-surgical and endovascular revascularizations. German and English literature has been considered. Eligibility criteria were verified by three independent reviewers. Disagreement was resolved by discussion involving a fourth reviewer. 580 articles were identified. After exclusion of non-eligible studies, 61 papers from 30 countries remained, respectively 850,072 patients. The included studies showed that PAD prevalence differed between diabetic vs. non-diabetic populations (20-50% vs. 10-26%), and further by age, gender, ethnicity, duration of existing diabetes, and geographic region. The included studies revealed worse outcomes regarding perioperative complications, amputation rate, and mortality rate in diabetic patients when compared to non-diabetic patients. In both groups, the amputation rates decreased during the research period. This review emphasizes an interrelationship between PAD and DM. To improve the outcomes, early detection of PAD in diabetic patients, and vice versa, should be recommended. The results of this systematic review may help to update societal practice guidelines.

A meta-analysis of mortality after minor amputation among patients with diabetes and/or peripheral vascular disease

OBJECTIVE

Foot complications in patients with diabetes or peripheral artery disease (PAD) are serious events in the life of these patients that often lead to amputations and mortality. No evidence synthesis has been reported on the mortality rates after minor lower extremity amputation; thus, a quantitative evidence synthesis was needed.

METHODS

A systematic literature search was performed to identify studies that had reported the survival or mortality rates after a minor LEA. The studies were required to include one or more of the following primary outcomes: mortality rate at 30 days, 1 year, 3 years, 5 years, 6 to 7 years, or 8 to 9 years. The secondary outcomes were the mortality rates according to the anatomic location of the amputation in the foot and the independent risk factors for mortality.

RESULTS

A total of 28 studies with 17,325 subjects fulfilled the inclusion criteria. The meta-analytical results of the mortality rates were as follows: 3.5% at 1 month, 20% at 1 year, 28% at 3 years, 44.1% at 5 years, 51.3% at 6 to 7 years, and 58.5% at 8 to 9 years. From these studies of diabetic patients, age was the most consistent independent risk factor, followed by chronic kidney disease, PAD, and coronary artery disease. One study of patients with PAD had reported diabetes as an independent risk factor for mortality. The subgroup analysis of the four studies reporting the outcomes of patients with PAD showed greater 3- and 5-year mortality rates compared with the overall and "diabetic" results.

CONCLUSIONS

Mortality after minor amputation for patients with diabetes and/or PAD was found to be very high. Compared with the reported cancer data, survival was worse than that for many cancers. Just as in the case of major amputations, minor amputations should be considered a pivotal event in the life of these patients.

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.

Epidemiology and Risk of Amputation in Patients With Diabetes Mellitus and Peripheral Artery Disease

Peripheral artery disease (PAD) stems from atherosclerosis of lower extremity arteries with resultant arterial narrowing or occlusion. The most severe form of PAD is termed chronic limb-threatening ischemia and carries a significant risk of limb loss and cardiovascular mortality. Diabetes mellitus is known to increase the incidence of PAD, accelerate disease progression, and increase disease severity. Patients with concomitant diabetes mellitus and PAD are at high risk for major complications, such as amputation. Despite a decrease in the overall number of amputations performed annually in the United States, amputation rates among those with both diabetes mellitus and PAD have remained stable or even increased in high-risk subgroups. Within this cohort, there is significant regional, racial/ethnic, and socioeconomic variation in amputation risk. Specifically, residents of rural areas, African-American and Native American patients, and those of low socioeconomic status carry the highest risk of amputation. The burden of amputation is severe, with 5-year mortality rates exceeding those of many malignancies. Furthermore, caring for patients with PAD and diabetes mellitus imposes a significant cost to the healthcare system-estimated to range from $84 billion to $380 billion annually. Efforts to improve the quality of care for those with PAD and diabetes mellitus must focus on the subgroups at high risk for amputation and the disparities they face in the receipt of both preventive and interventional cardiovascular care. Better understanding of these social, economic, and structural barriers will prove to be crucial for cardiovascular physicians striving to better care for patients facing this challenging combination of chronic diseases.

Trends and outcomes of non-traumatic major lower extremity amputations in an Irish tertiary referral hospital

OBJECTIVES

Data on vascular patients following amputation in Ireland is lacking, limiting capability to plan services. This paper seeks to benchmark survival and rehabilitation outcomes among vascular patients in Ireland following lower extremity amputation (LEA), and compare subgroups of those undergoing transfemoral (TFA) or transtibial amputation (TTA).

METHODS

A review was conducted of all patients who underwent non-traumatic TFA or TTA from 2000 to 2009 in a tertiary vascular surgery centre. Demographics, surgical data, perioperative outcomes, medium-term functional outcomes, and survival were assessed.

RESULTS

One hundred and seventy-two patients (2:1 male: female) underwent 192 non-traumatic LEAs. Median age for TFA was 75 years and TTA 67 (p = 0.002). A percentage of 36.5% had undergone prior attempts at surgical revascularization, 25% had undergone prior distal amputation or debridement. Thirty-three (17%) required stump revision. Twenty-three (13.2%) died in hospital. Median survival for those who died in hospital was 17 days (0-367), versus 17 months (2-106) for those who survived to discharge.

CONCLUSION

LEA for vascular pathology has significant morbidity and mortality, with long in-patient stays and short median survival; there is need to focus on improving quality of life in postoperative pathways.

In peripheral artery disease, diabetes is associated with reduced physical activity level and physical function and impaired cardiac autonomic control: A cross-sectional study

BACKGROUND

Diabetes has been considered a major risk factor for peripheral artery disease (PAD). The effect of diabetes on daily physical activity level and cardiovascular function in PAD patients is poorly known.

OBJECTIVE

To analyze the effect of diabetes on physical activity level, physical function and cardiovascular health parameters in patients with PAD and claudication symptoms.

METHODS

Cross-sectional study of 267 PAD patients, 146 without and 121 with diabetes. Physical activity levels were objectively measured by using an accelerometer, and time spent in sedentary (0-100 counts/min), light (101-1040 counts/min) and moderate to vigorous (≥1041 counts/min) physical activity was obtained. Physical function assessment included the 6-min walk test, handgrip strength test and short physical performance battery. Cardiovascular health parameters measured were brachial blood pressure, heart rate variability, and arterial stiffness.

RESULTS

Diabetic PAD patients spent more time in sedentary behavior (P=0.001, effect size [ES] 0.234) and less time in light (P=0.003, ES=0.206) and moderate-to-vigorous physical activity (P<0.001, ES=0.258) than non-diabetic PAD patients. Diabetic PAD patients presented lower 6-min walk distance (P=0.005, ES=0.194) and impaired cardiac autonomic modulation (standard deviation of all NN intervals [SDNN], P<0.001, ES=0.357; square root of the mean of the sum of the squares of differences between adjacent NN intervals [RMSSD], P<0.001, ES=0.280; and NN50 count divided by the total number of all NN intervals [pNN50], P<0.001, ES=0.291) as compared with non-diabetic PAD patients. After adjustment for confounders, diabetes remained associated with sedentary behavior (P=0.011), light (P=0.020) and moderate-to-vigorous physical activity (P=0.008), 6-min walk distance (P=0.030), SDNN (P<0.001), RMSSD (P=0.004), and PNN50 (P=0.004).

CONCLUSION

Diabetic PAD patients presented lower physical activity level, reduced physical function and impaired autonomic modulation as compared with non-diabetic PAD patients.

Rates and timing of subsequent amputation after initial minor amputation

OBJECTIVE

Studies evaluating major amputation after initial minor amputation are few with rates of subsequent major amputation ranging from 14% to 35% with limited understanding of associated comorbidities and time to limb loss. The aim of this study is to determine the major amputation rates for patients who had already undergone an initial minor amputation and determine which factors are associated with the need for subsequent major amputation.

METHODS

Using statewide data between 2005 and 2013, patients with peripheral artery disease (PAD), diabetes mellitus (DM), and combined PAD/DM who had a lower extremity ulcer and who had also undergone a minor amputation were identified. These patients were evaluated for the rate of subsequent major amputation and competing risk Cox proportional hazards modeling was used to study which factors were associated with the risk of subsequent limb loss.

RESULTS

The cohort consisted of 11,597 patients (DM, n = 4254; PAD, n = 2142; PAD/DM, n = 5201) with lower extremity ulcers who underwent an initial minor amputation. The rate of any subsequent amputation was highest in patients with PAD/DM (23% vs DM = 17%, PAD = 17%; P = not statistically significant). The rate of subsequent minor amputation was 16% in the PAD/DM versus 15.2% in PAD and 12.2% in patients with DM (P < .001). Patients with PAD/DM had the highest rate of subsequent major amputation (6.3% vs DM = 5.2%, PAD = 2.1%; P < .001). There was no statistically significant difference in the median time to major amputation among the three groups (PAD/DM, 13 months; DM, 14 months; PAD, 8.6 months; P = NS). Patients who were revascularized before a repeat minor amputation had a decreased risk of a major amputation compared with those who were intervened on after a repeat minor amputation (hazard ratio, 0.002; 95% confidence interval, 0-0.22). Patients treated completely in the outpatient setting were also less likely to undergo subsequent major amputation (hazard ratio, 0.7; 95% confidence interval, 0.5-0.98) compared with those who required hospitalization or presented to the emergency room.

CONCLUSIONS

Patients with ulcers and combined PAD and DM have a higher risk for secondary major and minor amputation than patients with either disease alone with half of the limb loss occurring at approximately 1 year after the initial minor amputation. Additionally, early diagnosis and appropriate referral may result in decreased limb loss for these patients.

Endovascular-First Treatment Is Associated With Improved Amputation-Free Survival in Patients With Critical Limb Ischemia

BACKGROUND

Critical limb ischemia remains a difficult disease to treat, with limited level one data. The BEST-CLI trial (Best Endovascular vs Best Open Surgical Therapy in Patients with Critical Limb Ischemia) is attempting to answer whether initial treatment with open surgical bypass or endovascular therapy improves outcomes, although it remains in enrollment. This study aims to compare amputation-free survival and reintervention rates in patients treated with initial open surgical bypass or endovascular intervention for ischemic ulcers of the lower extremities.

METHODS AND RESULTS

Using California nonfederal hospital data linked to statewide death data, all patients with lower extremity ulcers and a diagnosis of peripheral artery disease who underwent a revascularization procedure from 2005 to 2013 were identified. Propensity scores were formulated from baseline patient characteristics. Inverse probability weighting was used with Kaplan-Meier analysis to determine amputation-free survival and time to reintervention for open versus endovascular treatment. Mixed-effects Cox proportional hazards modeling was used to adjust for patient ability to manage their disease and hospital revascularization volume. A total of 16 800 patients were identified. Open surgical bypass was the initial treatment in 5970 (36%) while 10 830 (64%) underwent endovascular interventions. Patients in the endovascular group were slightly younger compared with the open group (70 versus 71 years, ±12 years; P<0.001). Endovascular-first patients were more likely to have comorbid renal failure (36% versus 24%), coronary artery disease (34% versus 32%), congestive heart failure (19% versus 15%), and diabetes mellitus (65% versus 58%; all P values <0.05). After inverse propensity weighting as well as adjustment for patient ability to manage their disease and hospital revascularization experience, open surgery first was associated with a worse amputation-free survival (hazard ratio, 1.16; 95% CI, 1.13-1.20) with no difference in mortality (hazard ratio, 0.94; 95% CI, 0.89-1.11). Endovascular first was associated with higher rates of reintervention (hazard ratio, 1.19; 95% CI, 1.14-1.23).

CONCLUSIONS

Patients with critical limb ischemia have multiple comorbidities, and initial surgical bypass is associated with poorer amputation-free survival compared with an endovascular-first approach, perhaps due to increased severity of wounds at the time of presentation.

Treatment of Diabetes in Older Adults: An Endocrine Society* Clinical Practice Guideline

OBJECTIVE

The objective is to formulate clinical practice guidelines for the treatment of diabetes in older adults.

CONCLUSIONS

Diabetes, particularly type 2, is becoming more prevalent in the general population, especially in individuals over the age of 65 years. The underlying pathophysiology of the disease in these patients is exacerbated by the direct effects of aging on metabolic regulation. Similarly, aging effects interact with diabetes to accelerate the progression of many common diabetes complications. Each section in this guideline covers all aspects of the etiology and available evidence, primarily from controlled trials, on therapeutic options and outcomes in this population. The goal is to give guidance to practicing health care providers that will benefit patients with diabetes (both type 1 and type 2), paying particular attention to avoiding unnecessary and/or harmful adverse effects.

Impact of chronic obstructive pulmonary disease on the outcomes of patients with peripheral artery disease

BACKGROUND

Peripheral artery disease (PAD) and chronic obstructive pulmonary disease (COPD) are both related with high in-hospital mortality. We aimed to investigate the impact of COPD on the in-hospital outcomes in PAD.

METHODS

PAD patients were selected based on ICD-code I70.2 of the German nationwide database, stratified for COPD and compared regarding adverse in-hospital outcomes.

RESULTS

Between 01/2005-12/2015, 5,611,827 inpatients (64.8% males) were diagnosed with PAD; of those, 13.6% were coded additionally with COPD. Overall, 277,894 PAD patients (5.0%) died during in-hospital course. Prevalence of cardiovascular diseases as well as cancer (12.1% vs. 7.0%, P < 0.001) was higher in PAD patients with COPD compared to PAD patients without COPD. PAD patients with COPD showed more often lower PAD stages according to Fontaine classification (PAD stage I: 27.1% vs. 19.3%, P < 0.001; PAD stage IIa: 34.9% vs. 35.5%, P < 0.001; PAD stage IIb: 14.5% vs. 13.6%, P < 0.001; PAD stage III: 11.8% vs. 14.8%, P < 0.001; PAD stage IV: 13.8% vs. 19.6%, P < 0.001). The all-cause in-hospital mortality was significantly higher in PAD patients with COPD compared to those without COPD (6.5% vs. 4.7%, P < 0.001). Cardiovascular events comprising pulmonary embolism and myocardial infarction occurred more often in coprevalence with PAD and COPD. COPD was an independent predictor of in-hospital death (OR 1.16 (95%CI 1.15-1.17) P < 0.001) and an independent predictor for pulmonary embolism (PE, OR 1.44 (1.40-1.49), P < 0.001) in PAD patients.

CONCLUSION

COPD was associated with a high in-hospital mortality in PAD patients probably driven by higher frequencies of PE and cancer.

Impact of diabetes type on treatment and outcome of patients with peripheral artery disease

BACKGROUND

The prevalence of diabetes mellitus and its associated complications such as peripheral artery disease is increasing worldwide. We aimed to explore the distinct impact of type 1 diabetes mellitus and type 2 diabetes mellitus on treatment and on short- and long-term outcome in patients with peripheral artery disease.

METHODS

Retrospective analysis of anonymized data of hospitalized patients covered by a large German health insurance. Assessment of patient's characteristics (comorbidities, complications, etc.) and outcome using multivariable Cox regression and Kaplan-Meier curves.

RESULTS

Among 41,702 patients with peripheral artery disease, 339 (0.8%) had type 1 diabetes mellitus and 13,151 (31.5%) had type 2 diabetes mellitus. Patients with diabetes mellitus had more comorbidities and complications than patients without diabetes mellitus ( p < 0.001). Type 1 diabetes mellitus patients exhibited the highest risk for limb amputation at 4-year follow-up (44.6% vs 35.1%, p < 0.001), while type 2 diabetes mellitus patients had higher mortality than type 1 diabetes mellitus (43.6% vs 31.0%, p < 0.001).

CONCLUSION

Although the fraction of type 1 diabetes mellitus among patients with peripheral artery disease and diabetes mellitus is low, it represents a subset of patients being at particular high risk for limb amputation. Research focused on elaborating the determinants of limb amputation and mortality in peripheral artery disease patients with diabetes mellitus is warranted to improve the poor prognosis of these patients.

Review of Socioeconomic Disparities in Lower Extremity Amputations: A Continuing Healthcare Problem in the United States

Lower extremity amputation is one of the most unfortunate, yet preventable, consequences of uncontrolled lower limb ischemia occurring secondary to diabetes mellitus or peripheral arterial disease. In the United States, racial and socioeconomic disparities are associated with significant differences seen in the incidence and type or level of lower extremity amputation among patients. Due to shifting demographics and the uncertain state of healthcare coverage, lower extremity amputation rates are only projected to increase in the future. Given the potential societal and individual costs associated with the loss of a limb, this review seeks to summarize the recent findings on disparities in the identification, treatments offered, and outcomes of lower limb ischemia in order to elucidate potential interventions at the practitioner and policy levels.

Obesity paradox in peripheral artery disease

BACKGROUND & AIMS

Previous studies have suggested an obesity survival paradox in patients with peripheral artery disease (PAD). We investigated the influence of obesity and underweight on adverse in-hospital outcomes in PAD.

METHODS

Patients diagnosed with PAD based on ICD-code I70.2 of the German nationwide database were stratified for obesity, underweight and a reference group with normal-weight/over-weight and compared regarding adverse in-hospital outcomes.

RESULTS

Between 01/2005-12/2015, 5,611,484 inpatients (64.8% males) were diagnosed with PAD; of those, 8.9% were coded with obesity and 0.3% with underweight. Obese patients were younger (70 (IQR 63/76) vs. 73 (66/80) years, P < 0.001), more frequently female (36.7% vs. 35.1%, P < 0.001), had less cancer (4.9% vs. 7.9%, P < 0.001) and had less treatment with major amputation (2.6% vs. 3.2%, P < 0.001) compared to the reference group. Overall, 277 876 (5.0%) patients died in-hospital. Obese patients showed lower mortality rate (3.2% vs. 5.1%, P < 0.001) compared to the reference group and reduced risk of in-hospital mortality (OR, 0.617 [95%CI 0.607-0.627], P < 0.001). This "obesity paradox" was demonstrated in obesity classes I (OR, 0.475 [95%CI 0.461-0.490], P < 0.001), II (OR, 0.580 [95%CI 0.557-0.605], P < 0.001), and III (OR, 0.895 [95%CI 0.857-0.934], P < 0.001) and was independent of age, sex and comorbidities. Underweight patients revealed higher in-hospital mortality (6.0% vs. 5.1%, P < 0.001) compared to the reference group (OR, 1.179 [95%CI 1.106-1.257], P < 0.001) and showed higher prevalence of cancer (22.0% vs. 7.9%, P < 0.001).

CONCLUSIONS

Coding for obesity is associated with lower in-hospital mortality in PAD patients relative to those with normal-weight/over-weight. This obesity survival paradox was independent of age, gender and comorbidities and observed for all obesity classes.

Predictors of Lower Extremity Amputation and Reamputation Associated With the Diabetic Foot

In the present study, we aimed to identify the comorbidities that would be predictive of requiring lower extremity amputation or reamputation for diabetic foot wounds. We performed a retrospective review of 132 consecutive patients who had undergone lower extremity amputations (110 patients) or reamputations (22 patients) for diabetic wounds from January 2013 to March 2016. We used multivariate logistic regression to calculate the odds ratios (ORs) for amputation and reamputation for various comorbidities. The ORs of undergoing amputation were greatest for adult males (OR 5.12, 95% confidence interval [CI] 1.56 to 13.04; p = .05) and those with longer term diabetes (OR 4.22, 95% CI 2.01 to 12.95; p = .05), wound infection (OR 3.94, 95% CI 1.04 to 9.00; p = .05), diabetic neuropathy (OR 3.53, 95% CI 1.07 to 9.11; p = .05), and a positive history of smoking (OR 3.04, 95% CI 1.55 to 9.89; p = .05). Similarly, the ORs of undergoing reamputation were greatest for adult males (OR 4.06, 95% CI 1.02 to 12.08; p = .05) and those with longer term diabetes (OR 3.67, 95% CI 1.94 to 11.42; p = .05), wound infection (OR 3.12; 95% CI 0.9 to 8.32; p = .05), diabetic neuropathy (OR 3.01, 95% CI 0.92 to 8.54; p = .05), and a positive history of smoking (OR 2.89, 95% CI 1.09 to 9.42; p = .05). The early identification of these comorbidities could help determine which patients are most likely to require amputation or reamputation.

[Operative treatment of diabetics with vascular complications : Secondary data analysis of diagnosis-related groups statistics from 2005 to 2014 in Germany]

BACKGROUND

In Germany approximately 40,000 amputations per year are performed on patients with diabetes mellitus, often with accompanying vascular complications.

OBJECTIVE

The aim of this study was to present the various degrees of severity of the vascular complications and the temporal changes of the treatment options in diabetics with vascular complications in Germany.

MATERIAL AND METHODS

The microdata of the diagnosis-related groups (DRG) statistics of the Federal Statistical Office were analyzed over the period from 2005 to 2014. All cases were included in which the main or secondary diagnosis of diabetes mellitus with concurrent vascular complications (diabetic angiopathy and peripheral arterial disease) was encrypted.

RESULTS

The median age of the 1,811,422 cases was 73 years and 62% were male. While the total number of amputations remained stable over time, there was a 41% reduction in knee-preserving and a 31% reduction in non-knee preserving major amputations with an 18% increase in minor amputations. Revascularization increased by 33% from 36 procedures in 2005 to 48 procedures per 100,000 inhabitants. The increase in revascularization was evident in the area of endovascular therapy alone where there was an increase of 78%.

CONCLUSION

Due to the significant increase in endovascular revascularization measures, there was a significant increase in the proportion of diabetes patients with vascular pathologies in whom revascularization was carried out. As a result, improved limb preservation was achieved despite equally high amputation rates due to increasing minor amputation rates.

Testing the sympathetic nervous system of the foot has a high predictive value for early amputation in patients with diabetes with a neuroischemic ulcer

OBJECTIVE

There is evidence from the literature that dysfunctionality of the sympathetic nervous system of the foot with subsequent loss of local autoregulation could be a predictor of early amputation in patients with diabetes with a neuroischemic ulcer. To confirm this we tested the functionality of the sympathetic nervous system in the foot in a consecutive group of 31 patients with diabetes with critical limb ischemia and non-healing neuroischemic ulcer.

RESEARCH DESIGN AND METHODS

Prospective cohort with retrospective analysis after 12 months of routinely acquired clinical data. All patients in the study group underwent angiography of the foot as part of a routine angioplasty procedure. Primary study endpoint was lower extremity amputation-free survival at 12 months. Because of the study design no other endpoints could be analyzed. The functionality of the sympathetic nervous system was tested with perfusion angiography.

RESULTS

Thirty-one patients were followed for 12 months. The Capillary Resistance Index (CRI) was used to measure the response of the sympathetic nervous system. CRI≥0.9 is the cut-off point for a non-responsive sympathetic nervous system. All patients (n=11) with a CRI≥0.9 underwent a major amputation before 12 months. Of all patients with a CRI only 15% underwent major amputation. The positive predictive value for major amputation before 12 months for patients with a CRI ≥ 0.9 was 100%.

CONCLUSIONS

A non-responsive sympathetic nervous system of the foot is a strong predictor of early major amputation (log rank p<0.001; HR 14.22; 95% CI 3.64 to 55.51).

Progression of disease preceding lower extremity amputation in Denmark: a longitudinal registry study of diagnoses, use of medication and healthcare services 14 years prior to amputation

OBJECTIVES

Patients with non-traumatic lower extremity amputation are characterised by high age, multi-morbidity and polypharmacy and long-term complications of atherosclerosis and diabetes. To ensure early identification of patients at risk of amputation, we need to gain knowledge about the progression of diseases related to lower extremity amputations during the years preceding the amputation.

DESIGN

A retrospective population-based national registry study.

SETTING

The study includes data on demographics, diagnoses, surgery, medications and healthcare services from five national registries. Data were retrieved from 14 years before until 1 year after the amputation. Descriptive statistics were used to describe the progression of diseases and use of medication and healthcare services.

PARTICIPANTS

An unselected cohort of patients (≥50 years; n=2883) subjected to a primary non-traumatic lower extremity amputation in 2010 or 2011 in Denmark.

RESULTS

The prevalence of atherosclerosis, hypertension and diabetes was 70%, 53% and 49%, respectively. Among patients with atherosclerosis, 42% had not received cholesterol-lowering treatment even though 87% had visited their general practitioner within the last year prior to amputation. Further, 16% were diagnosed with diabetes at the time of the amputation. The prevalence of cardiovascular diseases increased from 22% to 70%, atherosclerosis from 5% to 53% and diabetes from 17% to 35% over the 14 years preceding major amputation. Of all patients, 64% had been in contact with the hospital or outpatient clinics within the last 3 years, and 29% received a prescription of opioids 3 years prior to the amputation.

CONCLUSION

Among patients with non-traumatic lower extremity amputation, one-third live with undiagnosed and untreated atherosclerosis and one-sixth suffer from undiagnosed diabetes despite continuous contacts to general practitioner and the hospital. This study emphasises a need for enhanced focus, among both hospital clinicians and general practitioners, on the early identification of atherosclerosis and diabetes.

Endothelial deletion of mTORC1 protects against hindlimb ischemia in diabetic mice via activation of autophagy, attenuation of oxidative stress and alleviation of inflammation

Peripheral arterial disease (PAD) complicated with diabetes mellitus (DM) still remains a thorny issue due to lack of effective strategies. Our previous study has demonstrated that inhibition of mTORC1 protected adipose-derived stromal cells from hindlimb ischemic injury in PAD mice. However, whether inhibition of mTORC1 could protect against PAD in diabetes mellitus and the underlying mechanisms remained elusive. In this study, we employed endothelial-specific raptor (an essential component of the mTORC1 signaling complex) knockout (KO) mice (Tie2-mTORC1^ko) to investigate whether and how mTORC1 downregulation could alleviate hindlimb ischemic injury in diabetic mice. Tie2-mTORC1^ko mice and their wild-type littermates were intraperitoneally injected with streptozocin to induce type 1 diabetic model, after which the hyperglycemic mice were randomly allocated to sham operation or PAD operation (femoral artery ligation). The restoration of hindlimb blood perfusion and recovery of limb functions were improved in diabetic Tie2-mTORC1^ko PAD mice with significant improvements of autophagy, angiogenesis and vascular integrity as well as attenuation of apoptosis, inflammation and oxidative stress. In vitro, high glucose combining with hypoxia/serum deprivation treatment (HG+H/SD) significantly triggered apoptosis, reactive oxygen species generation and inflammation while inhibited autophagy and tube formation in HUVECs. The effect could be accentuated and attenuated by mTORC1 over-expression (TSC2 siRNA) and mTORC1 silencing (raptor siRNA), respectively. Moreover, autophagy inhibitor 3-MA could simulate the effects of TSC2 siRNA while autophagy inducer rapamycin could mimic the effects of raptor siRNA, suggesting that the beneficial effects of mTORC1 deletion were associated with autophagy induction. In conclusion, our present study demonstrates that endothelial mTORC1 deletion protects against hindlimb ischemic injury in diabetic mice possibly via activation of autophagy, attenuation of oxidative stress and alleviation of inflammation. Therapeutics targeting mTORC1 may therefore represents a promising strategy to rescue limb ischemia in diabetes mellitus.

Amputation trends for patients with lower extremity ulcers due to diabetes and peripheral artery disease using statewide data

OBJECTIVE

This study reports all-payer amputation rates using state-based administrative claims data for high-risk patients with lower extremity (LE) ulcers and concomitant peripheral artery disease (PAD), diabetes mellitus (DM), or combination PAD/DM. In addition, we characterize patient factors that affect amputation-free survival. We also attempted to create a measure of a patient's ability to manage chronic diseases or to access appropriate outpatient care for ulcer management by accounting for hospital and emergency department (ED) visits in the preceding 60 days to determine how this also affects amputation-free survival.

METHODS

Patients admitted to nonfederal hospitals, seen in an ED, or treated in an eligible ambulatory surgery center within California from 2005 through 2013 with an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code for a disease-specific LE ulcer were identified in the California Office of Statewide Health Planning and Development database. All subsequent hospital, ED, and ambulatory surgery center visits and procedures are captured to identify whether a patient underwent major amputation. Yearly amputation rates were determined to analyze trends. Amputation-free survival for the PAD, DM, and PAD/DM groups was determined. Cox modeling was used to evaluate the effect of patient characteristics.

RESULTS

There were 219,547 patients identified with an incident LE ulcer throughout the state. Of these, 131,731 were DM associated, 36,193 were PAD associated, and 51,623 were associated with both PAD and DM. From 2005 to 2013, the number of patients with LE ulcers who required inpatient admission, presented to the ED, or had outpatient procedures was stable. However, there was a statistically significant increase in overall disease-associated amputation rates from 5.1 in 2005 to 13.5 in 2013 (P < .001). Patients with PAD/DM had the greatest increase in amputation rates from 10 per 100 patients with LE ulcers in 2005 to 28 per 100 patients in 2013 (P < .001). Despite that patients with PAD/DM were 8 years younger than patients with PAD only, they had similar amputation-free survival. Within all age groups, men had worse amputation-free survival than women did. Race did not predict amputation-free survival, but having multiple prior ED or hospital admissions was a significant predictor of worse amputation-free survival.

CONCLUSIONS

Potentially preventable amputations associated with high-risk diseases are increasing among patients who require inpatient hospital admission, present to the ED, or require outpatient interventional treatment. This trend is most notable among patients with a combination of PAD and DM. Patients with repeated hospitalizations before admission for the LE ulcer had the highest risk of amputation.