Impact of diabetes on outcome in critical limb ischemia with tissue loss: a large-scaled routine data analysis

Towards uniform case-identification criteria in observational studies on peripheral arterial disease: A scoping review

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

From neglect to peril: diabetic ketoacidosis unleashing colonic necrosis and perforation in an adolescent girl with type 1 diabetes mellitus

OBJECTIVES

Abdominal pain is a common presentation in patients of diabetic ketoacidosis (DKA). However, this pain generally resolves with resolution of dehydration and acidosis. Persistence of abdominal pain even after resolution of ketosis and acidosis should warrant careful reassessment to find evidence of sepsis and concomitant abdominal pathology.

CASE PRESENTATION

We report a rare case of type 1 diabetes mellitus in a 15 year old girl diagnosed 6 months ago who presented with mild DKA (pH 7.24, HCO3 - 13.5 mmol/L). Her hospital course was extremely stormy and despite best of our efforts she succumbed due to colonic ischemia and perforation peritonitis.

CONCLUSIONS

A high index of suspicion for gut ischemia or perforation should be kept if DKA is associated with septic shock and there is suboptimal response to standard treatment. Mesenteric ischemia can occur in pediatric patients even with mild DKA having very poor diabetes control.

Randomized clinical trial to compare the efficacy of self-expanding bare metal nitinol stent and balloon angioplasty alone for below-the-knee lesions following successful balloon angioplasty: 1-year clinical outcomes

This prospective, multicenter, randomized study aimed to compare the 1-year clinical outcomes after primary stenting with self-expanding bare metal nitinol stent (SENS) and plain old balloon angioplasty (POBA) in patients with critical limb ischemia (CLI) and below-the-knee (BTK) lesions. Overall, 119 patients with CLI and BTK lesions were randomized to POBA alone (POBA group, 61 patients) or primary stenting with SENS (stenting group, 58 patients) after achieving acceptable POBA results in target BTK lesions. Clinical outcomes including amputation and revascularization rates were prospectively compared for 1 year. After 1 year, similar incidence rates of individual clinical endpoints, including cardiac death (6.5% vs. 5.1%, p > 0.999), myocardial infarction (1.6% vs. 0.0%, p > 0.999), repeat revascularization (19.6% vs. 18.9%, p = 0.922), target lesion revascularization (13.1% vs. 17.2%, p = 0.530), and amputation (4.9% vs. 0.0%, p = 0.244), were observed. POBA appeared to have acceptable treatment outcomes compared with primary stenting with SENS after 1 year in CLI patients with BTK lesions undergoing percutaneous transluminal angioplasty (PTA).

Contemporary Treatment and Outcome of Patients with Ischaemic Lower Limb Amputation: A Focus on Sex Differences

OBJECTIVE

Chronic limb threatening ischaemia (CLTI) has a devastating prognosis with high rates of lower limb amputation (LLA) and deaths. This is an illustration of contemporary management and the long term fate of patients after ischaemic LLA, particularly with respect to sex, using real world data.

METHODS

This was a multisectoral cross sectional and longitudinal analysis of health claims data from the largest German health insurance database (AOK). Data of 39 796 propensity score matched patients hospitalised for ischaemic LLA between 2010 and 2018 were analysed for cardiovascular comorbidities, treatment, and for subsequent cardiovascular and limb events, with a distinct focus on sex. Matching was performed, to ensure that the rate of major amputations and the age distribution were equal in both groups (in both sexes). An observation period of two years before index and a follow up (FU) period until 2019 were included.

RESULTS

Before index amputation, 68% of patients had received any kind of peripheral revascularisation. The use of statins (37.0% vs. 42.6%) and antithrombotic substances (54.9% vs. 61.8%) was lower in women than in men (p < .001). During two year FU, cardiovascular and limb events occurred among women and men as follows: limb re-amputation (26.7% vs. 31.2%), myocardial infarction (10.9% vs. 14.5%), stroke (20.8% vs. 20.7%), and death from any cause (51.0% vs. 53.3%, p < .001 except for stroke). After adjustment for cardiovascular comorbidities and vascular procedures, female sex was associated with a higher probability of death (HR 1.04, 95% CI 1.04 - 1.04).

CONCLUSION

Patients undergoing ischaemic LLA still have a poor prognosis marked by high rates of recurrent cardiovascular and limb events resulting in a > 50% mortality rate within two years. The continuous lack of guideline recommended therapies, particularly in women, may be associated with the persisting poor outcome, necessitating urgent further investigation.

PLAC8-Mediated Activation of NOX4 Signalling Restores Angiogenic Function of Endothelial Colony-Forming Cells in Experimental Hypoxia

Ischaemic cardiovascular disease is associated with tissue hypoxia as a significant determinant of angiogenic dysfunction and adverse remodelling. While cord blood-derived endothelial colony-forming cells (CB-ECFCs) hold clear therapeutic potential due to their enhanced angiogenic and proliferative capacity, their impaired functionality within the disease microenvironment represents a major barrier to clinical translation. The aim of this study was to define the specific contribution of NOX4 NADPH oxidase, which we previously reported as a key CB-ECFC regulator, to hypoxia-induced dysfunction and its potential as a therapeutic target. CB-ECFCs exposed to experimental hypoxia demonstrated downregulation of NOX4-mediated reactive oxygen species (ROS) signalling linked with a reduced tube formation, which was partially restored by NOX4 plasmid overexpression. siRNA knockdown of placenta-specific 8 (PLAC8), identified by microarray analysis as an upstream regulator of NOX4 in hypoxic versus normoxic CB-ECFCs, enhanced tube formation, NOX4 expression and hydrogen peroxide generation, and induced several key transcription factors associated with downstream Nrf2 signalling. Taken together, these findings indicated that activation of the PLAC8-NOX4 signalling axis improved CB-ECFC angiogenic functions in experimental hypoxia, highlighting this pathway as a potential target for protecting therapeutic cells against the ischaemic cardiovascular disease microenvironment.

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.

Skeletal Muscle Bioenergetics in Critical Limb Ischemia and Diabetes

INTRODUCTION

Mitochondrial dysfunction is implicated in the metabolic myopathy accompanying peripheral artery disease (PAD) and critical limb ischemia (CLI). Type-2 diabetes mellitus (T2DM) is a major risk factor for PAD development and progression to CLI and may also independently be related to mitochondrial dysfunction. We set out to determine the effect of T2DM in the relationship between CLI and muscle mitochondrial respiratory capacity and coupling control.

METHODS

We studied CLI patients undergoing revascularization procedures or amputation, and non-CLI patients with or without T2DM of similar age. Mitochondrial respiratory capacity and function were determined in lower limb permeabilized myofibers by high-resolution respirometry.

RESULTS

Fourteen CLI patients (65 ± 10y) were stratified into CLI patients with (n = 8) or without (n = 6) T2DM and were compared to non-CLI patients with (n = 18; 69 ± 5y) or without (n = 19; 71 ± 6y) T2DM. Presence of CLI but not T2DM had a marked impact on all mitochondrial respiratory states in skeletal muscle, adjusted for the effects of sex. Leak respiration (State 2, P < 0.025 and State 4o, P < 0.01), phosphorylating respiration (P < 0.001), and maximal respiration in the uncoupled state (P < 0.001), were all suppressed in CLI patients, independent of T2DM. T2DM had no significant effect on mitochondrial respiratory capacity and function in adults without CLI.

CONCLUSIONS

Skeletal muscle mitochondrial respiratory capacity was blunted by ∼35% in patients with CLI. T2DM was not associated with muscle oxidative capacity and did not moderate the relationship between muscle mitochondrial respiratory capacity and CLI.

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

Background

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

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

Results

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

Conclusions

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

Safety and Effectiveness of Endovascular Therapy for the Treatment of Peripheral Artery Disease in Patients with and without Diabetes Mellitus

This study investigated the distribution of risk factors, lesion characteristics and endovascular revascularization (EVR) strategies in patients with peripheral arterial disease (PAD) with vs without diabetes mellitus (DM). Data were collected within the RECcording COurses of vasculaR Diseases (RECCORD) registry. Demographic data, lesion localization (iliac vs femoropopliteal vs below-the-knee (BTK)) and lesion complexity score (LCS) based on number of affected segments, and lesion length (< 10 vs 10-20 vs > 20 cm), EVR strategies and peri-procedural complications were analysed in 786 patients with and 1337 without diabetes mellitus. Patients with diabetes mellitus were older (71.6 ± 9.6 vs 69.4 ± 10.5 years, P < .001) and had higher LCS and more often BTK lesions (P < .05 for all). Lesions were treated less frequently with stents (48.7 vs 59.6%, P < .001) in patients with diabetes mellitus, whereas a non-significant trend was noticed for higher DCB treatment rates (48.3 vs 44.4%, P = .07). Post-interventional ankle-brachial index (ABI) increase was similar (from .77 ± .28 to .92 ± .25 with diabetes mellitus and from .74 ± .21 to .90 ± .20 without diabetes mellitus, P < .001 for both). Peri-/post-procedural complications were low in both groups (4.6%). Patients with diabetes mellitus, who undergo endovascular revascularization are older, have more comorbidities and higher target lesion complexity. However, treatment success rates are similar and complication rates are low.

Two-Stage Gene Therapy (VEGF, HGF and ANG1 Plasmids) as Adjunctive Therapy in the Treatment of Critical Lower Limb Ischemia in Diabetic Foot Syndrome

One of the most serious problems in people with diabetes is diabetic foot syndrome. Due to the peripheral location of atherosclerotic lesions in the arterial system of the lower extremities, endovascular treatment plays a dominant role. However, carrying out these procedures is not always possible and does not always bring the expected results. Gene therapy, which stimulates angiogenesis, improves not only the inflow from the proximal limb but also the blood redistribution in individual angiosomes. Due to the encouraging results of sequential treatment consisting of intramuscular injections of VEGF/HGF bicistronic plasmids followed by a month of ANG1 plasmids, we decided to use the described method for the treatment of critical ischemia of the lower limbs in the course of diabetes and, more specifically, in diabetic foot syndrome. Twenty-four patients meeting the inclusion criteria were enrolled in the study. They were randomly divided into two equal groups. The first group of patients was subjected to gene therapy, where the patients received intramuscular injections of pIRES/VEGF165/HGF plasmids and 1 month of ANG-1 plasmids. The remaining patients constituted the control group. Gene therapy was well tolerated by most patients. The wounds healed significantly better in Group 1. The minimal value of ABI increased significantly in Group 1 from 0.44 ± 0.14 (± standard deviation) to 0.47 ± 0.12 (with p = 0.028) at the end of the study. There were no significant differences in the control group. In the gene treatment group, PtcO2 increased significantly (from 28.71 ± 10.89 mmHg to 33.9 ± 6.33 mmHg with p = 0.001), while in Group 2, no statistically significant changes were found. The observed resting pain decreased significantly in both groups (Group 1 decreased from 6.80 ± 1.48 to 2.10 ± 1.10; p < 0.001; the control group decreased from 7.44 ± 1.42 to 3.78 ± 1.64 with p < 0.001). In our study, we evaluated the effectiveness of gene therapy with the growth factors described above in patients with CLI in the course of complicated DM. The therapy was shown to be effective with minimal side effects. No serious complications were observed.

Antithrombotic Treatment Patterns of Patients with Symptomatic Peripheral Arterial Occlusive Disease in Germany: Evidence from Health Insurance Claims Data

Objectives: Patients with peripheral arterial occlusive disease (PAOD) are at risk of worsening limb symptoms, major adverse cardiovascular events and exhibit an impaired life expectancy. There is a lack of evidence on the extent of pharmacological secondary prevention in PAOD patients. This study assesses treatment patterns of antithrombotic agents in symptomatic PAOD patients. Methods: This is a retrospective cohort study using data from the second largest insurance fund in Germany, BARMER. We included symptomatic PAOD patients undergoing in-hospital treatment with an index admission between 1 January 2010 and 31 December 2017. Outcomes were proportions of single antiplatelets (SAPT), dual antiplatelets (DAPT), vitamin-K antagonists (VKA), or direct oral anticoagulants (DOAC) in the 12 months prior and 6 months after the index hospitalization. Non-parametric cumulative incidence for competing risks was estimated to account for censoring and death after discharge from hospital stay. Patient flows were visualised by alluvial diagrams. All analyses were stratified by intermittent claudication (IC) and chronic limb-threatening ischaemia (CLTI). The protocol was registered to ClinicalTrials.gov (NCT03909022). Results: A total of 80,426 unique patient encounters were identified. Mean age was 72.7 (46.3% female). Amongst all patients, 25.6% were on SAPT, 4.1% on DAPT, 9.1% on VKA, 3.9% on DOAC, 3.9% on both antiplatelets and oral anticoagulation, and 53.3% without any antithrombotic therapy during the 12 months before index stay. The estimated cumulative incidence was 37.9% SAPT, 14.8% DAPT, 7.5% VKA, 4.3% DOAC, 7.4% both, and 28.1% without any antithrombotic therapy during the 6 months after index stay. The considerable increases in antiplatelet therapy were mainly driven by the group of patients without antithrombotics before index stay. As compared with IC, patients who suffered from CLTI received less often antiplatelets but more often anticoagulants both before and after index stay. Conclusions: Utilisation rates of antithrombotic therapy increased considerably after in-hospital treatment for PAOD. Yet, remarkably high rates of symptomatic patients without any blood-thinning therapy constitute a major concern with respect to adequate secondary prevention of PAOD patients.

Closing the Gaps in Racial Disparities in Critical Limb Ischemia Outcome and Amputation Rates: Proceedings from a Society of Interventional Radiology Foundation Research Consensus Panel

Minority patients such as Blacks, Hispanics, and Native Americans are disproportionately impacted by critical limb ischemia and amputation due to multiple factors such as socioeconomic status, type or lack of insurance, lack of access to health care, capacity and expertise of local hospitals, prevalence of diabetes, and unconscious bias. The Society of Interventional Radiology Foundation recognizes that it is imperative to close the disparity gaps and funded a Research Consensus Panel to prioritize a research agenda. The following research priorities were ultimately prioritized: (a) randomized controlled trial with peripheral arterial disease screening of at-risk patients with oversampling of high-risk racial groups, (b) prospective trial with the introduction of an intervention to alter a social determinant of health, and (c) a prospective trial with the implementation of an algorithm that requires criteria be met prior to an amputation. This article presents the proceedings and recommendations from the panel.

Diabetes and other vascular risk factors in association with the risk of lower extremity amputation in chronic limb-threatening ischemia: a prospective cohort study

BACKGROUND

Patients with diabetes are at increased risk of developing chronic limb-threatening ischemia (CLTI) due to peripheral arterial disease, and this often results in lower extremity amputation (LEA). Little is known of the interaction between diabetes and other vascular risk factors in affecting the risk of CLTI.

METHODS

We investigated the association of diabetes, and its interaction with hypertension, body mass index (BMI) and smoking, with the risk of LEA due to CLTI in the population-based Singapore Chinese Health Study. Participants were interviewed at recruitment (1993-1998) and 656 incident LEA cases were identified via linkage with nationwide hospital database through 2017. Multivariate-adjusted Cox proportional hazards models were used to compute hazard ratios (HRs) and 95% CIs for the associations.

RESULTS

The HR (95% CI) for LEA risk was 13.41 (11.38-15.79) in participants with diabetes compared to their counterparts without diabetes, and the risk increased in a stepwise manner with duration of diabetes (P for trend < 0.0001). Hypertension and increased BMI independently increased LEA risk in those without diabetes but did not increase the risk in those with diabetes (P for interaction with diabetes ≤ 0.0006). Conversely, current smoking conferred a risk increment of about 40% regardless of diabetes status.

CONCLUSIONS

Although diabetes conferred more than tenfold increase in risk of LEA, hypertension and increased BMI did not further increase LEA risk among those with diabetes, suggesting a common mechanistic pathway for these risk factors. In contrast, smoking may act via an alternative pathway and thus confer additional risk regardless of diabetes status.

OUP accepted manuscript

Aims

The prevalence of chronic limb-threatening ischaemia (CLTI) is increasing and available data often derive from cohorts with various selection criteria. In the present study, we included CLTI patients and studied sex-related differences in their risk profile, vascular procedures, and long-term outcome.

Methods and results

We analysed 199 953 unselected patients of the largest public health insurance in Germany (AOK: Local healthcare funds), hospitalized between 2010 and 2017 for a main diagnosis of CLTI. A baseline period of 2 years before index hospitalization to assess comorbidities and previous procedures, and a follow-up period until 2018 were included. Female CLTI patients were older (median 81.4 vs. 73.8 years in males; P < 0.001) and more often diagnosed with hypertension, atrial fibrillation, chronic heart failure, and chronic kidney disease. Male patients suffered more frequently from diabetes mellitus, dyslipidaemia, smoking, cerebrovascular disease, and chronic coronary syndrome (all P < 0.001). Within hospitalized CLTI patients, females represent the minority (43% vs. 57%; P < 0.001) and during index hospitalization, women underwent less frequently diagnostic angiographies (67 vs. 70%) and revascularization procedures (61 vs. 65%; both P < 0.001). Moreover, women received less frequently guideline-recommended drugs like statins (35 vs. 43%) and antithrombotic therapy (48 vs. 53%; both P < 0.001) at baseline. Interestingly, after including age and comorbidities in a Cox regression analysis, female sex was associated with increased overall-survival (OS) [hazard ratio (HR) 0.95; 95% confidence interval (CI) 0.94–0.96] and amputation-free survival (AFS) (HR 0.84; 95% CI 0.83–0.85; both P < 0.001).

Conclusion

Female patients with CLTI were older, underwent less often vascular procedures, and received less frequently guideline-recommended medication. Nevertheless, female sex was independently associated with better OS and AFS during follow-up.

Major limb amputation and mortality in patients with neuro-ischaemic lower extremity wounds managed in a tertiary hospital: Focus on the differences among patients with diabetes, peripheral arterial disease and both

A majority of lower extremities neuro‐ischaemic wounds (NIU) are related to: (a) only diabetes (DM); (b) only peripheral artery disease (PAD); (c) co‐existing diabetes and peripheral artery disease (DM‐PAD). This study aims to characterise the major clinical outcomes of forementioned three groups of lower extremity wound patients in Singapore. Patients hospitalised for lower extremity NIU between January 2014 and October 2017 in a tertiary hospital in Singapore were analysed. Patients' major limb amputation and mortality were assessed using Cox regression models. Cumulative survival and amputation‐free survival among the three classified groups were calculated using Kaplan‐Meier analysis. Compared with patients with only DM, those in the PAD group and the DM‐PAD group had higher risk of major limb amputation (adjusted hazard ratio: 2.47, 95% CI: 1.65‐3.70; adjusted hazard ratio: 2.01, 95% CI: 1.53‐2.65 respectively) and mortality (adjusted hazard ratio: 2.36, 95% CI: 1.57‐3.55; adjusted hazard ratio: 2.46, 95% CI: 1.86‐3.26 respectively). The 3‐year survival and amputation‐free survival were lowest in the DM‐PAD group (52.1% and 41.5% respectively), followed by the PAD group (53.3% and 44.6% respectively) and the DM group (74.2% and 68.5% respectively). Lower extremity NIU patients with PAD or DM‐PAD were found to have poorer clinical prognosis than those with DM only.

Macrophage Polarization as a Novel Therapeutic Target for Endovascular Intervention in Peripheral Artery Disease

Peripheral artery disease (PAD) has a significant impact on human health, affecting 200 million people globally. Advanced PAD severely diminishes quality of life, affecting mobility, and in its most severe form leads to limb amputation and death. Treatment of PAD is among the least effective of all endovascular procedures in terms of long-term efficacy. Chronic inflammation is a key driver of PAD; however, stents and coated balloons eluting antiproliferative drugs are most commonly used. As a result, neither stents nor coated balloons produce durable clinical outcomes in the superficial femoral artery, and both have recently been associated with significantly increased mortality. This review summarizes the most common clinical approaches and limitations to treating PAD and highlights the necessity to address the underlying causes of inflammation, identifying macrophages as a novel therapeutic target in the next generation of endovascular PAD intervention.

Autologous cell therapy in diabetes‑associated critical limb ischemia: From basic studies to clinical outcomes (Review)

Cell therapy is becoming an attractive alternative for the treatment of patients with no‑option critical limb ischemia (CLI). The main benefits of cell therapy are the induction of therapeutic angiogenesis and neovascularization that lead to an increase in blood flow in the ischemic limb and tissue regeneration in non‑healing cutaneous trophic lesions. In the present review, the current state of the art of strategies in the cell therapy field are summarized, focusing on intra‑operative autologous cell concentrates in diabetic patients with CLI, examining different sources of cell concentrates and their mechanisms of action. The present study underlined the detrimental effects of the diabetic condition on different sources of autologous cells used in cell therapy, and also in delaying wound healing capacity. Moreover, relevant clinical trials and critical issues arising from cell therapy trials are discussed. Finally, the new concept of cell therapy as an adjuvant therapy to increase wound healing in revascularized diabetic patients is introduced.

Patients with Diabetes Complicated by Peripheral Artery Disease: the Current State of Knowledge on Physiotherapy Interventions

Diabetes mellitus (DM) is one of the major public health problems that account for morbidity, mortality, and disability worldwide. The presence of DM increases the risk of peripheral artery disease (PAD), as well as accelerates its course, making these patients more susceptible to ischemic events and impaired functional status. Unfortunately, alternative treatments for vascular complications in diabetes are poorly researched. Physiotherapy (kinesitherapy combined with different physical therapy agents) in individuals with DM and coexisting PAD may offer an important complementary therapy alternative. Early therapeutic measures can significantly improve patient outcomes, reduce cardiovascular risk, and improve daily life quality. The article provides an update on the current state of knowledge on physiotherapy interventions in the course of DM in patients with coexisting PAD.

Sex related differences in therapy and outcome of patients with intermittent claudication in a real-world cohort

BACKGROUND AND AIMS

The prevalence of lower extremity artery disease (LEAD) is increasing worldwide and sex-related differences are a current matter of debate.

METHODS

We analysed claims data on unselected patients with in-patient treatment for LEAD with intermittent claudication (IC; Rutherford grade 1-3) from 01.01.2014 to 31.12.2015. Data files included diagnostic and procedural information from two years before index, and a five-year follow-up.

RESULTS

Our analysis comprised 42,197 IC patients, thereof 28,520 (68%) male. Male patients were younger (median: 66.4 years vs. 72.6 years) but presented with higher frequency of cardiovascular risk factors such as diabetes (40% female vs. 46% male), atrial fibrillation (13% vs. 17%), chronic coronary syndrome (41% vs. 53%), chronic heart failure (23% vs. 27%), or chronic kidney disease (29% vs. 32%; all p < 0.001; age adjusted). Revascularisation applied in 80% of patients, thereof endovascular approach predominantly in female and surgery in male patients. Concomitant pharmacotherapy with statins (74% at 2 years) and platelet inhibitors (75% respectively) were long lasting below guideline recommendation, under-use being more pronounced in women. Two years after index, one-third of IC patients had subsequent revascularisation, one-quarter progressed to chronic limb threatening ischemia (CLTI), and 2% underwent amputation. Male sex was an independent risk factor for long-term mortality (female HR 0.75; 95%-CI 0.72-0.79; p < 0.001) and CLTI (female HR 0.89; 95%-CI 0.86-0.92; p < 0.001) during follow-up.

CONCLUSIONS

The majority of in-patient treated patients for IC are male, presenting with worse cardiovascular risk profiles. In view of a general under-supply with statins and platelet inhibitors, women received somewhat less often preventive medication. Despite low LEAD stages at index, serious prognosis was observed in the long term. Particularly male patients were at high risk for all-cause mortality and the combined endpoint CLTI and death.

Endovascular Treatment for Critical Limb Ischemia in Type II Diabetes Mellitus Involving Femoropopliteal and Infrapopliteal Segments: Revascularization Strategy

Purpose

To determine if further endovascular infrapopliteal angioplasty in combination with femoropopliteal revascularization improves the clinical outcomes regarding major amputation rate, rate of secondary interventions, and mortality in diabetic type-II patients presented with critical lower limb ischemia (CLI).

Patients and Methods

This is a retrospective study in which all type-II diabetic patients with CLI at King Abdullah University Hospital between October 2015 and September 2019 were identified. Patients with concomitant femoropopliteal and infrapopliteal vessels atherosclerotic lesions (total occlusion or more than 50% stenosis) who received successful endovascular treatment were included. Patients were divided into 2 groups. Group-I included patients treated for femoropopliteal segment alone, while Group-II included patients treated for both femoropopliteal and infrapopliteal segments. The outcomes of the two groups were compared regarding major amputation rate, rate of secondary interventions, and mortality. In addition, demographic data, atherosclerotic lesions distributions and cardiovascular risk factors were also collected and analyzed.

Results

In all, 90 patients (65 males and 25 females) with a mean age of 67.5±12 years were included. In Group-I; 44 patients (48.9%) were included (36 males and 8 females) with a mean age of 67±12 years. In group-II; 46 patients (51.1%) were included (29 males and 17 females) with a mean age of 68±13 years. The major amputation rate was higher and statistically significant in Group-I (38.6% vs 17.4%, p-value = 0.034). However, the secondary interventions and the mortality rates showed no statistically significant differences (56.8% vs 39.1%, p-value = 0.139) and (22.7% vs 28.3%, p-value = 0.632), respectively.

Conclusion

Endovascular infrapopliteal angioplasty in combination with femoropopliteal revascularization in diabetic type-II patients with CLI improves the clinical outcome regarding major amputation rate. However, there were no significant differences regarding the rate of secondary interventions and the mortality rate.

Prevalence of the Academic Research Consortium high bleeding risk criteria in patients undergoing endovascular therapy for peripheral artery disease in lower extremities

The Academic Research Consortium (ARC) recently published a definition of patients at high bleeding risk (HBR) undergoing percutaneous coronary intervention. However, the prevalence of the ARC-HBR criteria in patients undergoing endovascular therapy (EVT) for peripheral artery disease in lower extremities has not been thoroughly investigated. This study sought to investigate the prevalence and impact of the ARC-HBR criteria in patients undergoing EVT. We analyzed 277 consecutive patients who underwent their first EVT from July 2011 to September 2019. We applied the full ARC-HBR criteria to the study population. The primary end point was a composite outcome of all-cause mortality, Bleeding Academic Research Consortium 3 or 5 bleeding, and lower limb amputation within 12 months of EVT. Among the 277 patients, 193 (69.7%) met the ARC-HBR criteria. HBR patients had worse clinical outcomes compared with non-HBR patients at 12 months after EVT, including a higher incidence of the composite primary outcome (19.2% vs. 3.6%, p < 0.001) and all-cause death (7.8% vs. 0%, p = 0.007). In a multivariate Cox proportional hazards regression analysis, presence of the ARC-HBR criteria [hazard ratio (HR) 4.15, 95% confidence interval (CI) 1.25-13.80, p = 0.020], body mass index (HR 1.13, 95% CI 1.01-1.27, p = 0.042), diabetes mellitus (HR 2.70, 95% CI 1.28-5.69, p = 0.009), hyperlipidemia (HR 0.41, 95% CI 0.21-0.80, p = 0.009), and infrapopliteal lesions (HR 3.51, 95% CI 1.63-7.56, p = 0.001) were independent predictors of the primary composite outcome. Approximately 70% of Japanese patients undergoing EVT met the ARC-HBR criteria, and its presence was strongly associated with adverse outcomes within 12 months of EVT.

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.

[Macroangiopathy in diabetes mellitus]

Peripheral artery occlusive disease is a prevalent but underdiagnosed manifestation in patients with diabetes and also in patients with diabetic foot ulceration. There is insufficient awareness of its clinical manifestations, including intermittent claudication and critical limb ischemia and of its risk of adverse limb outcomes. This review aims to highlight essential elements of the prevalence of peripheral artery disease in patients with diabetes and the the pathway of clinical diagnosis. We report the actual standards and evidence based, interdisciplinary management including conservative, interventional and surgical treatment options and also the needs of follow-up care.

Fatty Acid Binding Protein 4-A Circulating Protein Associated with Peripheral Arterial Disease in Diabetic Patients

Diabetic patients with peripheral arterial disease (PAD) often suffer from poor clinical outcomes such as limb-loss. Fatty acid binding protein 4 (FABP4) is mainly expressed by adipocytes and is known to play a significant role in the development of atherosclerosis. In this study, we sought to investigate whether FABP4 is associated with PAD in patients with type 2 diabetes mellitus (DM). FABP4 plasma levels were studied in 119 diabetic patients with PAD (DM-PAD) and 49 diabetic patients without PAD (DM-noPAD) presenting to St. Michael’s Hospital between October 2017 and September 2018. Levels of FABP4 in DM-PAD patients (23.34 ± 15.27 ng/mL) were found to be over two-fold higher than the levels in DM-noPAD patients (10.3 ± 7.59 ng/mL). Regression analysis demonstrated a significant association between FABP4 levels and DM-PAD after adjusting for age, sex, prior history of coronary arterial disease and white blood cells count (OR, 2.77; 95% CI, 1.81–4.31; p-value = 0.001). Relative to DM-noPAD controls, plasma FABP4 levels in DM-PAD patients were noted to be inversely correlated with the ankle brachial index (ABI; r= −0.374, p-value < 0.001). The diagnostic ability of FABP4 was investigated using receiver operator curves (ROC) and area under the curve (AUC) analysis. FABP4 had an AUC of 0.79, which improved to 0.86 after adjusting for age, sex and prior history of coronary arterial disease. This raises a possibility of utilizing FABP4 as a biomarker for diagnosing PAD in diabetic patients.

Double VEGF/HGF Gene Therapy in Critical Limb Ischemia Complicated by Diabetes Mellitus

Critical leg ischemia (CLI) complicated by diabetes mellitus (DM), which is a very common and dangerous disease, represents the ultimate stage of peripheral arterial disease. Patients are treated with antiplatelet drugs, statins and limb revascularization, but a significant number of patients are not candidate for revascularization. Literature shows that in such cases, gene therapy could be a perfect therapeutic option. The aim of our study was to evaluate efficacy of double vascular endothelial growth factor/hepatocyte growth factor (VEGF/HGF) gene therapy in patients with CLI complicated by DM. We observed that 90 days after administration, serum level of VEGF and ankle-brachial index increased significantly (p < 0.001) and rest pain decreased significantly compared with the control group (p < 0.002). Moreover considerable improvement in vascularization was observed in computed tomography angiography (P = 0.04). Based on the results of this study, we suggest that the therapy with pIRES/VEGF165/HGF bicistronic plasmid administration is a safe and effective method of treatment of patients with both CLI and DM. Graphical abstract.

Cellular Based Strategies for Microvascular Engineering

Vascularization is a major hurdle in complex tissue and organ engineering. Tissues greater than 200 μm in diameter cannot rely on simple diffusion to obtain nutrients and remove waste. Therefore, an integrated vascular network is required for clinical translation of engineered tissues. Microvessels have been described as <150 μm in diameter, but clinically they are defined as <1 mm. With new advances in super microsurgery, vessels less than 1 mm can be anastomosed to the recipient circulation. However, this technical advancement still relies on the creation of a stable engineered microcirculation that is amenable to surgical manipulation and is readily perfusable. Microvascular engineering lays on the crossroads of microfabrication, microfluidics, and tissue engineering strategies that utilize various cellular constituents. Early research focused on vascularization by co-culture and cellular interactions, with the addition of angiogenic growth factors to promote vascular growth. Since then, multiple strategies have been utilized taking advantage of innovations in additive manufacturing, biomaterials, and cell biology. However, the anatomy and dynamics of native blood vessels has not been consistently replicated. Inconsistent results can be partially attributed to cell sourcing which remains an enigma for microvascular engineering. Variations of endothelial cells, endothelial progenitor cells, and stem cells have all been used for microvascular network fabrication along with various mural cells. As each source offers advantages and disadvantages, there continues to be a lack of consensus. Furthermore, discord may be attributed to incomplete understanding about cell isolation and characterization without considering the microvascular architecture of the desired tissue/organ.

High-fat diet pre-conditioning improves microvascular remodelling during regeneration of ischaemic mouse skeletal muscle

AIM

Critical limb ischaemia (CLI) is characterized by inadequate angiogenesis, arteriolar remodelling and chronic myopathy, which are most severe in type 2 diabetic patients. Hypertriglyceridaemia, commonly observed in these patients, compromises macrovascular function. However, the effects of high-fat diet-induced increases in circulating lipids on microvascular remodelling are not established. Here, we investigated if high-fat diet would mimic the detrimental effect of type 2 diabetes on post-ischaemia vascular remodelling and muscle regeneration, using a mouse model of hindlimb ischaemia.

METHODS

Male C57Bl6/J mice were fed with normal or high-fat diets for 8 weeks prior to unilateral femoral artery ligation. Laser doppler imaging was used to assess limb perfusion recovery. Vascular recovery, inflammation, myofibre regeneration and fibrosis were assessed at 4 or 14 days post-ligation by histology and RNA analyses. Capillary-level haemodynamics were assessed by intravital microscopy of control and regenerating muscles 14 days post-ligation.

RESULTS

High-fat diet increased muscle succinate dehydrogenase activity and capillary-level oxygen supply. At 4 days post-ligation, no diet differences were detected in muscle damage, inflammatory infiltration or capillary activation. At 14 days post-ligation, high fat-fed mice displayed accelerated limb blood flow recovery, elevated capillary and arteriole densities as well as greater red blood cell supply rates and capillary-level oxygen supply. Regenerating muscles from high fat-fed mice displayed lower interstitial fat and collagen deposition.

CONCLUSION

The muscle-level adaptations to high-fat diet improved multiple aspects of muscle recovery in response to ischaemia and did not recapitulate the worse outcomes seen in diabetic CLI patients.

Outcome of patients with chronic limb-threatening ischemia with and without revascularization

Summary: Background: Patients with chronic critical limb-threatening ischemia (CLTI) are at high risk of amputation and death. Despite the general recommendation for revascularization in CTLI in the guidelines, the underlying evidence for such a recommendation is limited. The aim of our study was to assess the outcome of patients with CLTI depending on the use of revascularization in a retrospective real-world cohort. Patients and methods: Administrative data of the largest German Health insurance (BARMER GEK) were provided for all patients that were hospitalized for the treatment of CLTI Rutherford category (RF) 5 and 6 between 2009 and 2011. Patients were followed-up until December 31st, 2012 for limb amputation and death in relation to whether patients did (Rx +) or did not have (Rx −) revascularization during index-hospitalization. Results: We identified 15,314 patients with CLTI at RF5 (n = 6,908 (45.1%)) and RF6 (n = 8,406 (54.9%)), thereof 7,651 (50.0%) underwent revascularization (Rx +) and 7,663 (50.0%) were treated conservatively (Rx −). During follow-up (mean 647 days; 95% CI 640–654 days) limb amputation (46.5% Rx− vs. 40.6% Rx+, P < 0.001) and overall mortality (48.2% Rx− vs. 42.6% Rx+, P < 0.001) were significantly lower in the subgroup Rx+. Conclusions: In a real-world setting, only half of CLTI were revascularized during the in-hospital treatment. Though, revascularization was associated with significantly better observed short- and long-term outcome. These data do not allow causal conclusion due to lack of data on the underlying reason for applied or withheld revascularization and therefore may involve a relevant selection bias.

Editor's Choice - Long Term Survival after Femoropopliteal Artery Revascularisation with Paclitaxel Coated Devices: A Propensity Score Matched Cohort Analysis

OBJECTIVE

The aim of this study was to determine the survival of patients after use of paclitaxel coated devices (PCX), as a recent meta-analysis of randomised trials reported higher mortality in patients treated with PCX balloons and stents METHODS: A retrospective health insurance claims analysis of patients covered by the second largest insurance fund in Germany, BARMER, was used to identify index femoropopliteal arterial interventions between 1 January 2010 and 31 December 2018. To ensure first PCX exposure, patients with prior deployment of PCX were excluded. The study cohort was stratified into patients with chronic limb threatening ischaemia (CLTI) and intermittent claudication (IC), then into balloons vs. stents cohorts. Within each stratum PCX were compared with uncoated devices. Propensity score matching was used to balance the study groups. Survival was evaluated using the Kaplan-Meier method and Cox regression.

RESULTS

There were 37 914 patients (mean age 73.3 years; 48.8% female) included in the study. The annual proportion of PCX use increased from 3% to 39% during the study period for CLTI and from 4% to 48% for IC (both p < .001). Paclitaxel coated balloons and stents were associated with improved overall survival (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.77-0.90), amputation free survival (HR 0.85, 95% CI 0.78-0.91), and freedom from major cardiovascular events (HR 0.82, 95% CI 0.77-0.89) vs. uncoated devices at five years for CLTI. In IC cohort, mortality was significantly lower after using drug coated balloons (DCB) (HR 0.87, 95% CI 0.76-0.99) or combined DCB and drug eluting stents (HR 0.88, 95% CI 0.80-0.98).

CONCLUSION

In this large health insurance claims analysis, rapid adoption of PCX, higher long term survival, better amputation free survival, and lower rates of major cardiovascular events were seen after their use for the treatment of CLTI.

Presentation Pattern of Lower Extremity Endovascular Intervention versus Percutaneous Coronary Intervention

AIM

The aim of the current study is to describe the presentation pattern of symptomatic peripheral artery disease undergoing endovascular therapy (EVT) in comparison to symptomatic coronary artery disease undergoing percutaneous coronary intervention (PCI) based on data from nationwide databases.

METHODS

Data were extracted from the nationwide procedural databases of EVT and PCI in Japan (J-EVT and J-PCI) between 2012 and 2017. The presentation pattern was investigated using a Poisson regression model, including the month, seasonality, and weekend (versus weekday) as the explanatory variables. Seasonality was expressed as a cosine function of a 12-month period, and its significance was evaluated using the Fisher-Yates shuffle method.

RESULTS

A total of 41,906 and 62,585 cases underwent EVT for critical limb ischemia (CLI) and intermittent claudication (IC), respectively, whereas 518,858 and 504,139 cases underwent PCI for acute coronary syndrome (ACS) and stable angina (SA). The procedural volume increased by 21.6%, 12.3%, 4.5%, and 3.6% per year in CLI, IC, ACS, and SA. CLI and ACS, but not IC or SA, showed a significant volume seasonality. Compared with ACS, CLI demonstrated a larger peak-to-trough ratio of seasonality (1.75 versus 1.21; P＜0.001), and a later peak appearance (February-March versus January-February by 1.37 months; P＜0.001). The procedural volume on weekends relative to weekdays was smaller for SA, IC, and CLI than for ACS. These distinct features were observed in a diabetic population and a non-diabetic population.

CONCLUSIONS

The current study analyzed nationwide procedural databases and demonstrated the presentation pattern of symptomatic PAD and CAD warranting revascularization.

Diabetes mellitus and other cardiovascular risk factors in lower-extremity peripheral artery disease versus coronary artery disease: an analysis of 1,121,359 cases from the nationwide databases

BACKGROUND

Lower-extremity peripheral artery disease (LE-PAD) and coronary artery disease (CAD) are both pathologically rooted in atherosclerosis, and their shared clinical features regarding the exposure to cardiovascular risk factors have been emphasized. However, comparative data of the two cardiovascular diseases (CVDs) were so far lacking. The purpose of this study was to directly compare the clinical profile between cases undergoing endovascular therapy (EVT) for LE-PAD and those undergoing percutaneous coronary intervention (PCI).

METHODS

Data were extracted from the nationwide procedural databases of EVT and PCI in Japan (J-EVT and J-PCI) between 2012 and 2017. A total of 1,121,359 cases (103,887 EVT cases for critical limb ischemia [CLI] or intermittent claudication and 1,017,472 PCI cases for acute coronary syndrome [ACS] or stable angina) were analyzed. Heterogeneity in clinical profile between CVDs was evaluated using the C statistic of the logistic regression model for which dependent variable was one CVD versus another, and explanatory variables were clinical profile. When two CVDs were completely discriminated from each other by the developed model, the C statistic (discrimination ability) of the model would be equal to 1, indicating that the two CVDs were completely different in clinical profile. On the other hand, when two CVDs were identical in clinical profile, the developed model would not discriminate them at all, with the C statistic equal to 0.5.

RESULTS

Mean age was 73.5 ± 9.3 years in LE-PAD patients versus 70.0 ± 11.2 years in CAD patients (P < 0.001). The prevalence of diabetes mellitus and end-stage renal disease was 1.96- and 6.39-times higher in LE-PAD patients than in CAD patients (both P < 0.001). The higher prevalence was observed irrespective of age group. The exposure to other cardiovascular risk factors and the likelihood of cardiovascular risk clustering also varied between the diseases. The between-disease heterogeneity in patient profile was particularly evident between CLI and ACS, with the C statistic equal to 0.833 (95% CI 0.831-0.836).

CONCLUSIONS

The current study, an analysis based on nationwide procedural databases, confirmed that patient profiles were not identical but rather considerably different between clinically significant LE-PAD and CAD warranting revascularization.

Diabetes and risk of peripheral artery disease in patients undergoing first-time coronary angiography between 2000 and 2012 - a nationwide study

Background

The risk of peripheral artery disease (PAD) in patients with diabetes mellitus (DM) and coronary artery disease (CAD) is an important and inadequately addressed issue. Our aim is to examine the impact of DM on risk of PAD in patients with different degrees of CAD characterized by coronary angiography (CAG).

Methods

Using nationwide registers we identified all patients aged ≥18 years, undergoing first time CAG between 2000 and 2012. Patients were categorized into DM/Non-DM group, and further classified into categories according to the degree of CAD i.e., no-vessel disease, single-vessel disease, double-vessel disease, triple-vessel disease, and diffuse disease. Risk of PAD was estimated by 5-year cumulative-incidence and adjusted multivariable Cox-regression models.

Results

We identified 116,491 patients undergoing first-time CAG. Among these, a total of 23.969 (20.58%) had DM. Cumulative-incidence of PAD among DM patients vs. non-DM were 8.8% vs. 4.9% for no-vessel disease, 8.2% vs. 4.8% for single-vessel disease, 10.2% vs. 6.0% for double-vessel disease, 13.0% vs. 8.4% for triple-vessel disease, and 6.8% vs. 6.1% for diffuse disease, respectively. For all patients with DM, the cox-regression analysis yielded significantly higher hazards of PAD compared with non-DM patients with HR 1.70 (no-vessel disease), 1.96 (single-vessel disease), 2.35 (double-vessel disease), 2.87 (triple-vessel disease), and 1.46 (diffuse disease), respectively (interaction-p 0.042).

Conclusion

DM appears to be associated with increased risk of PAD in patients with and without established CAD, with increasing risk in more extensive CAD. This observation indicates awareness on PAD risk in patients with DM, especially among patients with advanced CAD.

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

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

Prospective study on clinical characteristics of Japanese diabetic patients with chronic limb-threatening ischemia presenting Fontaine stage IV

The aim of this prospective cross-sectional study was to reveal clinical characteristics of Japanese diabetic patients with chronic limb-threatening ischemia (CLTI) presenting ischemic unhealed ulcer/gangrene (Fontaine stage IV) in the real-world settings. The present study included 132 Japanese diabetic patients who underwent endovascular therapy for CLTI presenting Fontaine stage IV. The prevalence of diabetes-related complications, as well as prior history of ankle-brachial index (ABI) measurement before CLTI onset, was evaluated adopting multiple imputation (50 times). Duration of diabetes was referred to as time from diagnosis. The patients were aged 70 ± 10 years, with duration of diabetes 23 ± 12 years. The diabetes-related complications were so common that only 17% (95% confidence interval: 11-24%) and 25% (17-33%) of the population were free from advanced micro- and macroangiopathies, respectively. The clustering of advanced macroangiopathies was not significantly associated with duration of diabetes (P = 0.62). On the other hand, that of advanced microangiopathies was significantly positively associated with duration of diabetes (P = 0.004). However, even in patients with duration of diabetes < 10 years, as many as 63% (38-87%) of patients had at least one advanced microangiopathy. Only 31% (22-39%) of the patients had prior history of ABI measurement before CLTI onset. The history was inversely associated with age (P = 0.005). In conclusion, the advanced diabetes-related complications were highly prevalent, even in those whose diabetes was diagnosed less than a decade before. In addition, only a few patients had ever undergone ABI measurement before CLTI onset.

Unmet medical needs in intermittent Claudication with diabetes and coronary artery disease-A "real-world" analysis on 21 197 PAD patients

BACKGROUND

Peripheral artery disease (PAD) is frequently co-prevalent with coronary artery disease (CAD) and diabetes (DM). The study aims to define the burden of CAD and/ or DM in PAD patients at moderate stages and further to evaluate its impact on therapy and outcome.

METHODS

Study is based on health insurance claims data of the BARMER reflecting an unselected "real-world" scenario. Retrospective analyses were based on 21 197 patients hospitalized for PAD Rutherford 1-3 between 1 January 2009 to 31 December 2011, including a 4-year follow-up (median 775 days).

RESULTS

In PAD patients, CAD is prevalent in 25.3% (n = 5355), DM in 23.5% (n = 4976), and both CAD and DM in 8.2% (n = 1741). Overall, in-hospital mortality was 0.4%, being increased if CAD was present (CAD alone: OR 1.849; 95%-CI 1.066-3.208; DM alone: OR 1.028; 95%-CI 0.520-2.033; CAD and DM: OR 3.115; 95%-CI 1.720-5.641). Both, CAD and DM increased long-term mortality (CAD alone: HR 1.234; 95%-CI 1.106-1.376; DM alone: HR 1.260; 95%-CI 1.125-1.412; CAD and DM: HR 1.76; 95%-CI 1.552-1.995). DM further increased long-term amputation risk (DM alone: HR 2.238; 95%-CI 1.849-2.710; DM and CAD: HR 2.199; 95%-CI 1.732-2.792), whereas CAD (alone) did not.

CONCLUSIONS

In a greater perspective, the data identify also mild to modest stage PAD patients at particular risk for adverse outcomes in presence of CAD and/or DM. CAD and DM both are related with a highly increased risk of long-term mortality even in intermittent claudication, and DM independently increased amputation risk.

Clinical characteristics of Japanese diabetic patients with critical limb ischemia presenting Fontaine stage IV

The aim of the current study was to reveal the clinical characteristics of Japanese diabetic patients with critical limb ischemia (CLI) presenting ischemic unhealed ulcer/gangrene (Fontaine stage IV) in the real-world settings. The current retrospective cross-sectional study included consecutive 282 Japanese diabetic patients who underwent endovascular therapy for CLI presenting Fontaine stage IV. The prevalence of diabetes-related complications was estimated adopting multiple imputation (50 times). The patients were aged 70 ± 10 years. Median duration of diabetes was 21 (interquartile range 12-31) years. The prevalence of proliferative diabetic retinopathy, end-stage renal disease on regular dialysis, stroke, coronary artery disease, and chronic heart failure was estimated at 48% (95% confidence interval 39-56%), 52% (46-58%), 34% (28-39%), 48% (42-54%), and 35% (29-41%), respectively. The prevalence of stroke, coronary artery disease, and chronic heart failure was not significantly associated with the duration of diabetes (all p > 0.05). On the other hand, the prevalence of proliferative diabetic retinopathy and end-stage renal disease on regular dialysis was significantly positively associated with the duration of diabetes (both p < 0.05). However, these prevalences reached as high as ~ 30% even in patients with duration of diabetes < 10 years. In conclusion, the advanced stage of diabetes-related complications was prevalent in patients with CLI presenting Fontaine stage IV.

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.

Lower extremity arterial disease in patients with diabetes: a contemporary narrative review

Lower-extremity arterial disease (LEAD) is a major endemic disease with an alarming increased prevalence worldwide. It is a common and severe condition with excess risk of major cardiovascular events and death. It also leads to a high rate of lower-limb adverse events and non-traumatic amputation. The American Diabetes Association recommends a widespread medical history and clinical examination to screen for LEAD. The ankle brachial index (ABI) is the first non-invasive tool recommended to diagnose LEAD although its variable performance in patients with diabetes. The performance of ABI is particularly affected by the presence of peripheral neuropathy, medial arterial calcification, and incompressible arteries. There is no strong evidence today to support an alternative test for LEAD diagnosis in these conditions. The management of LEAD requires a strict control of cardiovascular risk factors including diabetes, hypertension, and dyslipidaemia. The benefit of intensive versus standard glucose control on the risk of LEAD has not been clearly established. Antihypertensive, lipid-lowering, and antiplatelet agents are obviously worthfull to reduce major cardiovascular adverse events, but few randomised controlled trials (RCTs) have evaluated the benefits of these treatments in terms of LEAD and its related adverse events. Smoking cessation, physical activity, supervised walking rehabilitation and healthy diet are also crucial in LEAD management. Several advances have been achieved in endovascular and surgical revascularization procedures, with obvious improvement in LEAD management. The revascularization strategy should take into account several factors including anatomical localizations of lesions, medical history of each patients and operator experience. Further studies, especially RCTs, are needed to evaluate the interest of different therapeutic strategies on the occurrence and progression of LEAD and its related adverse events in patients with diabetes.