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

Artificial intelligence of arterial Doppler waveforms to predict major adverse outcomes among patients with diabetes mellitus

OBJECTIVE

Patients with diabetes mellitus (DM) are at increased risk for peripheral artery disease (PAD) and its complications. Arterial calcification and non-compressibility may limit test interpretation in this population. Developing tools capable of identifying PAD and predicting major adverse cardiac event (MACE) and limb event (MALE) outcomes among patients with DM would be clinically useful. Deep neural network analysis of resting Doppler arterial waveforms was used to detect PAD among patients with DM and to identify those at greatest risk for major adverse outcome events.

METHODS

Consecutive patients with DM undergoing lower limb arterial testing (April 1, 2015-December 30, 2020) were randomly allocated to training, validation, and testing subsets (60%, 20%, and 20%). Deep neural networks were trained on resting posterior tibial arterial Doppler waveforms to predict all-cause mortality, MACE, and MALE at 5 years using quartiles based on the distribution of the prediction score.

RESULTS

Among 11,384 total patients, 4211 patients with DM met study criteria (mean age, 68.6 ± 11.9 years; 32.0% female). After allocating the training and validation subsets, the final test subset included 856 patients. During follow-up, there were 262 deaths, 319 MACE, and 99 MALE. Patients in the upper quartile of prediction based on deep neural network analysis of the posterior tibial artery waveform provided independent prediction of death (hazard ratio [HR], 3.58; 95% confidence interval [CI], 2.31-5.56), MACE (HR, 2.06; 95% CI, 1.49-2.91), and MALE (HR, 13.50; 95% CI, 5.83-31.27).

CONCLUSIONS

An artificial intelligence enabled analysis of a resting Doppler arterial waveform permits identification of major adverse outcomes including all-cause mortality, MACE, and MALE among patients with DM.

Brazilian Society of Angiology and Vascular Surgery 2023 guidelines on the diabetic foot

The diabetic foot interacts with anatomical, vascular, and neurological factors that challenge clinical practice. This study aimed to compile the primary scientific evidence based on a review of the main guidelines, in addition to articles published on the Embase, Lilacs, and PubMed platforms. The European Society of Cardiology system was used to develop recommendation classes and levels of evidence. The themes were divided into six chapters (Chapter 1 - Prevention of foot ulcers in people with diabetes; Chapter 2 - Pressure relief from foot ulcers in people with diabetes; Chapter 3 -Classifications of diabetic foot ulcers; Chapter 4 - Foot and peripheral artery disease; Chapter 5 - Infection and the diabetic foot; Chapter 6 - Charcot's neuroarthropathy). This version of the Diabetic Foot Guidelines presents essential recommendations for the prevention, diagnosis, treatment, and follow-up of patients with diabetic foot, offering an objective guide for medical practice.

Long-term limb salvage and functional outcomes for patients undergoing partial calcanectomy

INTRODUCTION

Partial calcanectomy (PC) can be performed to treat chronic heel ulcers in patients with calcaneal osteomyelitis. Patients undergoing PC often have multiple comorbidities, limited mobility, and face high risk of major limb amputation. This study examined the extent of vascular diagnostic testing and interventions as well as long-term outcomes in patients undergoing PC.

METHODS

A retrospective analysis was performed on patients who underwent PC for non-healing calcaneal ulcer over a ten-year period. Demographics, comorbidities, vascular testing, and procedural data were recorded. Additional subgroup analysis was performed according to presence or absence of peripheral arterial disease (PAD). Primary outcomes were major limb amputation (above or below the knee) and mortality. Secondary outcomes included successful wound healing, time to complete wound healing, re-interventions, and change in ambulatory status.

RESULTS

A total of 157 patients underwent partial calcanectomies on 162 limbs. 78.3% of patients had diabetes mellitus and 47.8% were diagnosed with PAD. Ankle brachial index with pulse volume recording (ABI/PVR) was performed for 46.5% (73/157) of patients, arterial duplex in 44.6% (70/157), and 19.7% (31/157) had a computed tomography angiogram. Lower extremity revascularization was performed in 28.4% of limbs (46/162). Independent ambulatory status was reported in 40.1% prior to PC and decreased to 17.9% by the time of last recorded follow-up (p < .00001). Long-term amputation-free survival was significantly higher in patients without PAD at 7 years (78.4% vs 57.1%, p = .02). Multivariate logistic regression analysis demonstrated that PAD and end-stage renal disease (ESRD) increased the odds of major limb amputation (OR 3.5 and 2.8, respectively), whereas ESRD and adjuvant podiatric procedures were associated with increased mortality (OR 4.8 and 4.8, respectively).

CONCLUSION

Non-invasive vascular testing should be obtained in all patients undergoing PC, in order to stratify risk of amputation and identify candidates for revascularization. Over the long-term, patients undergoing PC face significant risk of prolonged wound healing, decline in ambulatory status, and major limb amputation.

Peripheral Vascular Disease

Peripheral artery disease is most often caused by atherosclerosis. Arterial insufficiency from atherosclerotic blockages in the limbs can impair walking distance and put patients with severe disease at risk of limb loss. Management of the disease centers around early diagnosis, supervised exercise therapy and lifestyle modification, optimizing medical care (with the goal of reducing fatal cardiac and cerebrovascular events), and revascularization.

Association between red cell distribution width-and-albumin ratio and the risk of peripheral artery disease in patients with diabetes

Aim

The aim of this study is to explore the association between red blood cell distribution width-to-albumin ratio (RAR) and the risk of peripheral artery disease (PAD) in patients with diabetes.

Methods

This cross-sectional study extracted the data of 1,125 participants with diabetes from the National Health and Nutrition Examination Survey database. A weighted univariable logistic regression model was used to explore variables associated with PAD. With PAD as the outcome variable, a weighted logistic regression model was established. The odds ratio (OR) and 95% confidence interval (CI) were effect size.

Results

After adjusting for covariates, the risk of PAD in patients with diabetes was observed in those with higher RAR (OR = 1.83; 95% CI: 1.06-3.15). In addition, RAR ≥3.25 was related to increased risk of PAD in patients with diabetes (OR = 2.04; 95% CI: 1.05-3.95). In people with diabetes aged ≥65, RAR was a risk factor for PAD with an OR value of 2.67 (95% CI: 1.30-5.46). RAR ≥3.25 was associated with increased risk of PAD (OR = 3.06; 95% CI: 1.15-8.11) relative to RAR <2.80. In people with diabetes who smoked, the risk of PAD was elevated in those with RAR ≥3.25 (OR = 2.85; 95% CI: 1.28-6.32). As for patients with cardiovascular disease, the risk of PAD was elevated as the increase of RAR (OR = 2.31; 95% CI: 1.05-5.10). RAR ≥3.25 was correlated with increased risk of PAD (OR = 3.75; 95% CI: 1.42-9.87). The area under the curve of RAR for the risk of PAD in patients with diabetes was 0.631 (95% CI: 0.588-0.675).

Conclusion

A higher RAR was related to increased risk of PAD in patients with diabetes. The findings might offer a reference for the management of PAD in patients with diabetes.

Inconsistent Benefits From Mobile Information Communication Technology in Adults With Peripheral Arterial Disease

INTRODUCTION

Quality of evidence regarding telemedicine in adults with peripheral arterial disease has not been systematically appraised.

OBJECTIVES

To explore benefits and harms from mobile information communication technology devices and applications in peripheral arterial disease.

METHODS

Systematic rapid evidence review and appraisal with the grading of recommendations assessment, development, and evaluation working group approach.

RESULTS

Sixteen randomized controlled clinical trials (RCT) examined various self-monitoring devices, telemedicine platforms, and individualized telephone counseling. Low-quality evidence suggested that the odds of treatment failure (pooled Peto odds ratio 0.8; 95% CI, 0.4-1.7; 5 RCTs), adverse effects (pooled Peto odds ratio 0.9; 95% CI, 0.5-1.5; 2 RCTs), and physical performance (standardized mean difference in 6-minute walking test 0.2; 95% CI, -0.3-0.7; 4 RCTs) did not differ between mobile interventions and usual care. Single RCTs suggested large but inconsistent improvement in the quality of life: EuroQol5D standardized mean difference = 5.0 (95% CI, 4.4-5.7; 1 RCT) after telehealth program for promoting patient self-management and standardized mean difference = 1.4 (95% CI, 0.4-2.3; 1 RCT) after structured rehabilitation with mobile self-monitoring. Inconsistent reporting of patient-centered outcomes and small sample sizes hampered the quality of evidence.

CONCLUSIONS

Improved quality of life after specific mobile applications should be confirmed in powered RCTs and large postmarketing studies.

The intersocietal IWGDF, ESVS, SVS guidelines on peripheral artery disease in people with diabetes mellitus and a foot ulcer

Diabetes related foot complications have become a major cause of morbidity and are implicated in most major and minor amputations globally. Approximately 50% of people with diabetes and a foot ulcer have peripheral artery disease (PAD) and the presence of PAD significantly increases the risk of adverse limb and cardiovascular events. The International Working Group on the Diabetic Foot (IWGDF) has published evidence based guidelines on the management and prevention of diabetes related foot complications since 1999. This guideline is an update of the 2019 IWGDF guideline on the diagnosis, prognosis, and management of peripheral artery disease in people with diabetes mellitus and a foot ulcer. For this updated guideline, the IWGDF, the European Society for Vascular Surgery, and the Society for Vascular Surgery decided to collaborate to develop a consistent suite of recommendations relevant to clinicians in all countries. This guideline is based on three new systematic reviews. Using the Grading of Recommendations, Assessment, Development and Evaluation framework clinically relevant questions were formulated, and the literature was systematically reviewed. After assessing the certainty of the evidence, recommendations were formulated which were weighed against the balance of benefits and harms, patient values, feasibility, acceptability, equity, resources required, and when available, costs. Through this process five recommendations were developed for diagnosing PAD in a person with diabetes, with and without a foot ulcer or gangrene. Five recommendations were developed for prognosis relating to estimating likelihood of healing and amputation outcomes in a person with diabetes and a foot ulcer or gangrene. Fifteen recommendations were developed related to PAD treatment encompassing prioritisation of people for revascularisation, the choice of a procedure and post-surgical care. In addition, the Writing Committee has highlighted key research questions where current evidence is lacking. The Writing Committee believes that following these recommendations will help healthcare professionals to provide better care and will reduce the burden of diabetes related foot complications.

Sex and Racial Disparities in Peripheral Artery Disease

Several studies have shown that women and racial and ethnic minority patients are at increased risk of developing lower extremity peripheral artery disease and suffering adverse outcomes from it, but a knowledge gap remains regarding the underlying causes of these increased risks. Both groups are more likely to be underdiagnosed, have poorly managed contributory comorbidities, and incur disparities in treatment and management postdiagnosis. Opportunities for improvement in the care of women and racial and ethnic minorities with peripheral artery disease include increased rates of screening, higher rates of clinical suspicion (particularly in the absence of typical symptoms of intermittent claudication), and more aggressive risk factor management before and after the diagnosis of peripheral artery disease.

Diabetes- versus smoking-related thrombo-inflammation in peripheral artery disease

Peripheral artery disease (PAD) is a major health problem with increased cardiovascular mortality, morbidity and disabling critical limb threatening ischemia (CLTI) and amputation. Diabetes mellitus (DM) and cigarette smoke are the main risk factors for the development of PAD. Although diabetes related PAD shows an accelerated course with worse outcome regarding complications, mortality and amputations compared with non-diabetic patients, current medical treatment does not make this distinction and includes standard antiplatelet and lipid lowering drugs for all patients with PAD. In this review we discuss the pathophysiologic mechanisms of PAD, with focus on differences in thrombo-inflammatory processes between diabetes-related and smoking-related PAD, and hypothesize on possible mechanisms for the progressive course of PAD in DM. Furthermore, we comment on current medical treatment and speculate on alternative medical drug options for patients with PAD and DM.

The Intersocietal IWGDF, ESVS, SVS Guidelines on Peripheral Artery Disease in People With Diabetes Mellitus and a Foot Ulcer

Diabetes related foot complications have become a major cause of morbidity and are implicated in most major and minor amputations globally. Approximately 50% of people with diabetes and a foot ulcer have peripheral artery disease (PAD) and the presence of PAD significantly increases the risk of adverse limb and cardiovascular events. The International Working Group on the Diabetic Foot (IWGDF) has published evidence based guidelines on the management and prevention of diabetes related foot complications since 1999. This guideline is an update of the 2019 IWGDF guideline on the diagnosis, prognosis, and management of peripheral artery disease in people with diabetes mellitus and a foot ulcer. For this updated guideline, the IWGDF, the European Society for Vascular Surgery, and the Society for Vascular Surgery decided to collaborate to develop a consistent suite of recommendations relevant to clinicians in all countries. This guideline is based on three new systematic reviews. Using the Grading of Recommendations, Assessment, Development and Evaluation framework clinically relevant questions were formulated, and the literature was systematically reviewed. After assessing the certainty of the evidence, recommendations were formulated which were weighed against the balance of benefits and harms, patient values, feasibility, acceptability, equity, resources required, and when available, costs. Through this process five recommendations were developed for diagnosing PAD in a person with diabetes, with and without a foot ulcer or gangrene. Five recommendations were developed for prognosis relating to estimating likelihood of healing and amputation outcomes in a person with diabetes and a foot ulcer or gangrene. Fifteen recommendations were developed related to PAD treatment encompassing prioritisation of people for revascularisation, the choice of a procedure and post-surgical care. In addition, the Writing Committee has highlighted key research questions where current evidence is lacking. The Writing Committee believes that following these recommendations will help healthcare professionals to provide better care and will reduce the burden of diabetes related foot complications.

Understanding the Impact of COVID-19 on Angioplasty Service and Outcome of Patients Treated for Chronic Limb-Threatening Ischaemia: A Single-Centre Retrospective Cohort Study

We evaluated the impact of COVID-19 restriction on the angioplasty service and outcome of chronic limb-threatening ischaemia (CLTI) patients undergoing lower-limb angioplasty in a UK secondary care setting. Consecutive patients were analysed retrospectively. Pre-COVID-19 (08/2018-02/2020), 106 CLTI patients (91% Fontaine 4; 60% diabetes mellitus) and during COVID-19 (03/2020-07/2021) 94 patients were treated (86% Fontaine 4; 66% diabetes mellitus). While the average monthly number of patients treated did not change, the proportion of day cases significantly increased (53% to 80%), and hospitalised patients decreased. Patients treated in ≤14/5 days after referral significantly increased to 64/63%. Kaplan-Meier survival analysis (30-day/1-year) showed that neither wound healing nor mortality were significantly changed during COVID-19. In day cases, 1-year but not 30-day major amputations significantly increased, and clinically driven target-lesion revascularisation decreased during COVID-19. One-year mortality was significantly worse in hospitalised compared to day cases (14% vs. 43%) at similar wound healing rates (83% vs. 84%). The most frequent known cause of death was infectious disease (64%), while cardiovascular (21%) was less frequent. Despite COVID-19 restrictions, a safe and effective angioplasty service was maintained while shortening waiting times. Very high mortality rates in hospitalised patients may indicate that CLTI patients need to be referred and treated more aggressively earlier.

Investigating the joint application of negative pressure wound treatment and tissue therapy for chronic wounds in patients with diabetes

This study aimed to investigate the effectiveness of combined negative pressure wound therapy (NPWT) and human amniotic membrane in patients with chronic wounds associated with diabetes. A total of five patients with type 2 diabetes, including ischemic and mixed forms of diabetic foot syndrome, presenting with ischemic wounds of the lower extremities were included in this study. Patients with uncorrected limb ischemia were excluded. The treatment protocol included diabetes compensation (treatment with fractional insulin therapy), anticoagulant, metabolic therapy and angiotropic therapy, physical treatment methods, osteoporosis therapy with calcium preparations, and wound-specific interventions. The primary treatment approach involved the application of a vacuum bandage to the transplanted human amniotic membrane, which improved the adaptation of the flap to the wound surface, allowed the removal of excess wound exudate, and stimulated angiogenesis and reparative properties. The combined approach of NPWT and biotherapy was a safe and effective cure for diabetic wounds, promoting faster wound healing, reducing the need for autodermoplasty, and possibly reducing the necessity for high-level amputations.

Observation of the effect of angiojet to treat acute lower extremity arterial embolization

BACKGROUND

Through significant advances in the treatment of peripheral arterial occlusive disease, acute ischemia of the lower extremity is still associated with significant morbidity, limb threat and mortality. The two main causes of acute ischemia in lower extremities are arterial embolism and atherosclerotic arteries. Timely recognition and treatment of acute limb ischemia in emergency situations is essential in order to minimize the duration of ischemia.

AIM

To investigate the application effect of angiojet thrombolysis in the treatment of acute lower extremity arterial embolization.

METHODS

Sixty-two patients with acute lower extremity arterial embolization admitted to our hospital from May 2018 to May 2020 were selected. Among them, the observation group (twenty-eight cases) had received angiojet thrombolysis, and the control group (thirty-four cases) had received femoral artery incision and thrombectomy. After thrombus clearance, significant residual stenosis of the lumen was combined with balloon dilation and/or stent implantation. When the thrombus removal was not satisfactory, catheter-directed thrombolysis was performed. The incidence of postoperative complications, recurrence rate and recovery of the two groups were compared.

RESULTS

There were no significant differences in postoperative recurrence (target vessel reconstruction rate), anklebrachial index and the incidence of postoperative complications between the two groups (P > 0.05); there were statistically significant differences in postoperative pain score and postoperative rehabilitation between the two groups (P < 0.05).

CONCLUSION

The application of angiojet in the treatment of acute lower limb artery thromboembolism disease is safe and effective, minimally invasive, quicker recovery after operation, less postoperative complications, which is more suitable for the treatment of femoral popliteal arterial thromboembolism lesions. If the thrombus removal is not satisfactory, the combination of coronary artery aspiration catheter and catheterized directed thrombolysis can be used. Balloon dilation and stent implantation can be considered for obvious lumen stenosis.

Impact of microvascular complications on the outcomes of diabetic foot in type 2 diabetic patients with documented peripheral artery disease

PURPOSE

Microvascular disease (MVD) is associated with amputation linked to peripheral artery disease (PAD) in the general population. No study evaluated the impact of diabetic microvascular complications on the outcomes of vascular diabetic foot ulcers (DFU). The aim of the study was to investigate whether retinopathy, nephropathy, and polyneuropathy can predict the outcomes of DFU in type 2 diabetic patients with PAD.

METHODS

Three hundred and thirty-one consecutive patients with vascular DFU were enrolled and followed up for 44.1 ± 23.9 months.

RESULTS

The prevalence of retinopathy was significantly higher in subjects with ulcer persistence (45.2%; p < 0.01), minor amputation (48.9%; p < 0.001), and major amputation (57.9%; p < 0.001) than in healed patients (23.3%), and in non-survivors than in survivors (64.9 versus 20.5%; p < 0.001). The prevalence of nephropathy was significantly greater in subjects with ulcer persistence (83.9%; p < 0.01), minor amputation (86.7%; p < 0.001), and major amputation (94.7%; p < 0.001) than in those with healed DFU (64.4%), and in non-survivors than in survivors (88.3 versus 65.7%; p < 0.001). The prevalence of polyneuropathy was significantly higher in non-survivors than in survivors (76.6 versus 61.0%; p = 0.012). Multivariate analysis showed that absence of retinopathy (OR: 0.451; 95% CI: 0.250-0.815; p < 0.001) and nephropathy (OR: 0.450; 95% CI: 0.212-0.951; p = 0.036) were independently associated with healing. Moreover, retinopathy was a predictor both of minor amputation (OR: 2.291; 95% CI: 1.061-4.949; p = 0.034) and mortality (OR: 5.274; 95% CI: 2.524-11.020; p < 0.001). Polyneuropathy never entered the regression model.

CONCLUSIONS

Diabetic microvascular complications, in particular retinopathy, may predict the outcomes of vascular DFU. Longitudinal studies should confirm this finding.

Timing of Revascularization and Parenteral Antibiotic Treatment Associated with Therapeutic Failures in Ischemic Diabetic Foot Infections

For ischemic diabetic foot infections (DFIs), revascularization ideally occurs before surgery, while a parenteral antibiotic treatment could be more efficacious than oral agents. In our tertiary center, we investigated the effects of the sequence between revascularization and surgery (emphasizing the perioperative period of 2 weeks before and after surgery), and the influence of administering parenteral antibiotic therapy on the outcomes of DFIs. Among 838 ischemic DFIs with moderate-to-severe symptomatic peripheral arterial disease, we revascularized 608 (72%; 562 angioplasties, 62 vascular surgeries) and surgically debrided all. The median length of postsurgical antibiotic therapy was 21 days (given parenterally for the initial 7 days). The median time delay between revascularization and debridement surgery was 7 days. During the long-term follow-up, treatment failed and required reoperation in 182 DFI episodes (30%). By multivariate Cox regression analyses, neither a delay between surgery and angioplasty (hazard ratio 1.0, 95% confidence interval 1.0–1.0), nor the postsurgical sequence of angioplasty (HR 0.9, 95% CI 0.5–1.8), nor long-duration parenteral antibiotic therapy (HR 1.0, 95% CI 0.9–1.1) prevented failures. Our results might indicate the feasibility of a more practical approach to ischemic DFIs in terms of timing of vascularization and more oral antibiotic use.

Ankle Fractures in Diabetic Patients: A Critical Analysis

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Patients with diabetes are at higher risk for complications after surgical fixation of unstable fractures due to impaired neurovascular functioning and wound-healing capabilities.

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Patients with uncontrolled diabetes have higher rates of complications when compared with patients with controlled diabetes.

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Despite higher rates of complications, operative fixation of unstable ankle fractures in diabetic patients reliably leads to a functional lower extremity with an overall lower rate of complications than nonoperative management.

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Operatively and nonoperatively managed ankle fractures in patients with diabetes should remain non-weight-bearing for an extended period of time.

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Discussion of risk of poor outcomes including deep infection, loss of reduction, return to the operating room, and risk of arthrodesis or amputation should be explicitly discussed with patients and families when managing unstable ankle fractures in diabetic patients.

Impact of Glucagon-like peptide 1 receptor agonists on peripheral arterial disease in people with diabetes mellitus: A narrative review

Peripheral arterial disease (PAD) is a common macrovascular complication of diabetes mellitus (DM). Glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs) are among the latest class of antidiabetic medications that stimulate insulin synthesis and secretion and have been used for the management of type 2 DM. Apart from the effect on glycaemic control, GLP-1RAs also have a robust impact on weight reduction and have shown favorable effects on cardiovascular morbidity and mortality in cardiovascular outcome trials (CVOTs). The aim of this review was to examine the impact of GLP1-RAs on PAD among people with DM based on CVOTs, randomized controlled trials, observational studies as well as systematic reviews and meta-analyses. Data from retrospective studies and meta-analyses have shown superiority of these agents in comparison with other antidiabetic medications such as sodium-glucose cotransporter type 2 inhibitors and dipeptidyl peptidase-4 inhibitors in terms of PAD-related events. Nevertheless, data from CVOTs regarding the impact of GLP-1RAs on PAD are scarce and hence, safe conclusions regarding their effects cannot be drawn. Further prospective studies are needed to examine the impact of GLP-1RAs on PAD-related incidents including major adverse limb events, lower limb amputations and revascularization procedures.

Ankle Doppler for Cuffless Ankle Brachial Index Estimation and Peripheral Artery Disease Diagnosis Independent of Diabetes

Ankle brachial pressure index (ABPI) is the first-line test to diagnose peripheral artery disease (PAD). Its adoption in clinical practice is poor and its validity, particularly in diabetes, is limited. We hypothesised that ABPI can be accurately and precisely estimated based on cuffless Doppler waveforms. Retrospective analysis of standard ABPI and handheld Doppler waveform characteristics (n = 200). Prospective analysis of angle-corrected Doppler acceleration index (AccI, n = 148) and standard ABPI with testing of performance to diagnose PAD as assessed with imaging reference standards in consecutive patients. The highest AccI from handheld Doppler at ankle arteries was significantly logarithmically associated with the highest standard ABPI (E[y] = 0.32 ln [1.71 ∗ x + 1], p < 0.001, R2 = 0.68, n = 100 limbs). Estimated ABPI (eABPI) based on AccI closely resembled ABPI (r = 0.81, p < 0.001, average deviation −0.01 ± 0.13 [SD], n = 100 limbs). AccI from angle-corrected Doppler in patients without overt media sclerosis (ABPI ≤ 1.1) improved ABPI prediction (E[y] = 0.297 ∗ ln[0.039 ∗ x + 1], R2 = 0.92, p = 0.006, average deviation 0.00 ± 0.08, n = 100). In a population (n = 148 limbs) including diabetes (56%), chronic limb-threatening ischaemia (51%) and media sclerosis (32%), receiver operating characteristics analysis of (angle-corrected) eABPI performed significantly better than standard ABPI to diagnose PAD defined by ultrasound (ROC AUC = 0.99 ± 0.01, p < 0.001; sensitivity: 97%, specificity: 96%) at the ≤0.9 cut-off. This was confirmed with CT angiography (ROC AUC = 0.98, p < 0.001, sensitivity: 97%, specificity: 100%) and was independent of the presence of diabetes (p = 0.608). ABPI can be estimated based on ankle Doppler AccI without compression, and eABPI performs better than standard ABPI to diagnose PAD independent of diabetes. eABPI has the potential to be included as a standard component of lower extremity ultrasound.

Age-Dependent Decline in Common Femoral Artery Flow-Mediated Dilation and Wall Shear Stress in Healthy Subjects

Femoral artery (FA) endothelial function is a promising biomarker of lower extremity vascular health for peripheral artery disease (PAD) prevention and treatment; however, the impact of age on FA endothelial function has not been reported in healthy adults. Therefore, we evaluated the reproducibility and acceptability of flow-mediated dilation (FMD) in the FA and brachial artery (BA) (n = 20) and performed cross-sectional FA- and BA-FMD measurements in healthy non-smokers aged 22−76 years (n = 50). FMD protocols demonstrated similar good reproducibility. Leg occlusion was deemed more uncomfortable than arm occlusion; thigh occlusion was less tolerated than forearm and calf occlusion. FA-FMD with calf occlusion was lower than BA-FMD (6.0 ± 1.1% vs 6.4 ± 1.3%, p = 0.030). Multivariate linear regression analysis indicated that age (−0.4%/decade) was a significant independent predictor of FA-FMD (R2 = 0.35, p = 0.002). The age-dependent decline in FMD did not significantly differ between FA and BA (pinteraction agexlocation = 0.388). In older participants, 40% of baseline FA wall shear stress (WSS) values were <5 dyne/cm2, which is regarded as pro-atherogenic. In conclusion, endothelial function declines similarly with age in the FA and the BA in healthy adults. The age-dependent FA enlargement results in a critical decrease in WSS that may explain part of the age-dependent predisposition for PAD.

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.

Cocoa flavanol consumption improves lower extremity endothelial function in healthy individuals and people with type 2 diabetes

Background: diabetes and age are major risk factors for the development of lower extremity peripheral artery disease (PAD). Cocoa flavanol (CF) consumption is associated with lower risk for PAD and improves brachial artery (BA) endothelial function. Objectives: to assess if femoral artery (FA) endothelial function and dermal microcirculation are impaired in individuals with type 2 diabetes mellitus (T2DM) and evaluate the acute effect of CF consumption on FA endothelial function. Methods: in a randomised, controlled, double-blind, cross-over study, 22 individuals (n = 11 healthy, n = 11 T2DM) without cardiovascular disease were recruited. Participants received either 1350 mg CF or placebo capsules on 2 separate days in random order. Endothelial function was measured as flow-mediated dilation (FMD) using ultrasound of the common FA and the BA before and 2 hours after interventions. The cutaneous microvasculature was assessed using optical coherence tomography angiography. Results: baseline FA-FMD and BA-FMD were significantly lower in T2DM (FA: 3.2 ± 1.1% [SD], BA: 4.8 ± 0.8%) compared to healthy (FA: 5.5 ± 0.7%, BA: 6.0 ± 0.8%); each p < 0.001. Whereas in healthy individuals FA-FMD did not significantly differ from BA-FMD (p = 0.144), FA-FMD was significantly lower than BA-FMD in T2DM (p = 0.003) indicating pronounced and additional endothelial dysfunction of lower limb arteries (FA-FMD/BA-FMD: 94 ± 14% [healthy] vs. 68 ± 22% [T2DM], p = 0.007). The baseline FA blood flow rate (0.42 ± 0.23 vs. 0.73 ± 0.35 l min^-1, p = 0.037) and microvascular dilation in response to occlusion in hands and feet were significantly lower in T2DM subjects than in healthy ones. CF increased both FA- and BA-FMD at 2 hours, compared to placebo, in both healthy and T2DM subgroups (FA-FMD effect: 2.9 ± 1.4%, BA-FMD effect 3.0 ± 3.5%, each p_intervention< 0.001). In parallel, baseline FA blood flow and microvascular diameter significantly increased in feet (3.5 ± 3.5 μm, p_intervention< 0.001) but not hands. Systolic blood pressure and pulse wave velocity significantly decreased after CF in both subgroups (-7.2 ± 9.6 mmHg, p_intervention = 0.004; -1.3 ± 1.3 m s^-1, p_intervention = 0.002). Conclusions: individuals with T2DM exhibit decreased endothelial function that is more pronounced in the femoral than in the brachial artery. CFs increase endothelial function not only in the BA but also the FA both in healthy individuals and in those with T2DM who are at increased risk of developing lower extremity PAD and foot ulcers.

Peripheral artery disease and the risk of venous thromboembolism

Summary: Background: Peripheral artery disease (PAD) impacts 3–12% of patients worldwide and is characterized by endothelial dysfunction and inflammatory pathways which are also common to venous thromboembolism (VTE), but there is a paucity of evidence regarding VTE risk in PAD patients. We investigated whether PAD is an independent risk factor for VTE. Patients and methods: We reviewed medical records of patients undergoing ABI studies at Mayo Clinic from 01/1996-02/2020. We classified patients by ABI (low [<1.0], normal [1.0–1.4], or elevated [>1.4]), as well as by specific low ABI subgroup: severely reduced (ABI: 0.00–0.39), moderately reduced (0.40–0.69), mildly reduced (0.70–0.90), and borderline reduced (0.91–0.99). The primary outcome was incident VTE event (acute lower extremity deep vein thrombosis or pulmonary embolism) after ABI measurement. Multivariable Cox proportional regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for age, sex, active smoking, cancer, previous VTE, thrombophilia, anticoagulation, and revascularization. Results: 39,834 unique patients (mean age 66.3±14.3 years, median follow-up 34 months) were identified. 2,305 VTE events occurred in patients without PAD (13.0%), 2,218 in low ABI patients (13.0%), and 751 in elevated ABI patients (14.8%). After risk factor adjustment, VTE risk was modestly increased for PAD overall (HR: 1.12, 95% CI [1.06, 1.18]), including low ABI (HR: 1.11, 95% CI [1.04, 1.18]) and elevated ABI groups (HR: 1.15, 95% CI [1.04, 1.26]), compared to patients without PAD. The greatest VTE risk was in severely low ABI patients (HR: 1.46, 95% CI [1.31, 1.64]). Conclusions: In a large longitudinal cohort, we present strong clinical evidence of PAD, with low and elevated ABI, as an independent VTE risk factor, with the highest risk seen in patients with severely low ABI. Continued research is required to further investigate this relationship and its intersection with functional performance status to optimize VTE risk reduction or anticoagulation strategies in the PAD population.

Diabetes Mellitus and Its Impact on Patient-Profile and In-Hospital Outcomes in Peripheral Artery Disease

BACKGROUND

In patients with peripheral artery disease (PAD), the impact of diabetes mellitus (DM) on patient-profile and adverse in-hospital events is not well investigated.

METHODS

The German nationwide inpatient sample 2005-2019 was used for this analysis. Hospitalized PAD patients were stratified for DM and the influence of DM on patient-profile and adverse in-hospital events was investigated.

RESULTS

Our study comprised 2,654,871 hospitalizations (54.3% aged ≥70 years, 36.7% females) of patients with PAD in Germany 2005-2019. Among these, 864,691 (32.6%) patients had DM and 76,716 (2.9%) died during hospitalization. Diabetic PAD patients revealed an aggravated cardiovascular profile (Charlson Comorbidity Index: 6.0 (5.0-8.0) vs. 4.0 (3.0-5.0), p < 0.001). PAD patients with DM showed a higher rate of in-hospital mortality (3.5% vs. 2.6%, p < 0.001), as well as major adverse cardiovascular and cerebrovascular events (MACCE, 4.7% vs. 3.3%, p < 0.001) and had more often operated with amputation surgery (16.4% vs. 9.1%, p < 0.001). DM was an independent predictor of in-hospital mortality (OR 1.077 (95%CI 1.060-1.093), p < 0.001) and MACCE (OR 1.118 (95%CI 1.103-1.133), p < 0.001). In addition, amputations were also associated with DM (OR 1.804 (95%CI 1.790-1.818)), p < 0.001).

CONCLUSIONS

DM is associated with an unfavorable clinical patient-profile and higher risk for adverse events in PAD patients, including substantially increased in-hospital mortality as well as MACCE rate, and were more often associated with amputation surgeries.

Diabetes and peripheral artery disease: A review

Peripheral arterial disease (PAD) refers to partial or complete occlusion of the peripheral vessels of the upper and lower limbs. It usually occurs as part of systemic atherosclerosis in the coronary and cerebral arteries. The prevalence of PAD is expected to continue to increase in the foreseeable future owing to the rise in the occurrence of its major risk factors. Nonhealing ulcers, limb amputation and physical disability are some of its major complications. Diabetes mellitus (DM) remains a major risk for PAD, with DM patients having more than two-fold increased prevalence of PAD compared with the general population. The clinical presentation in people with DM also differs slightly from that in the general population. In addition, PAD in DM may lead to diabetic foot ulcers (DFUs), which precipitate hyperglycaemic emergencies and result in increased hospital admissions, reduced quality of life, and mortality. Despite the epidemiological and clinical importance of PAD, it remains largely under diagnosed and hence undertreated, possibly because it is largely asymptomatic. Emphasis has been placed on neuropathy as a cause of DFUs, however PAD is equally important. This review examines the epidemiology, pathophysiology and diagnosis of lower limb PAD in people with diabetes and relates these to the general population. It also highlights recent innovations in the management of PAD.

The Association of Periodontitis and Peripheral Arterial Occlusive Disease in a Prospective Population-Based Cross-Sectional Cohort Study

Objectives: Peripheral arterial occlusive disease (PAOD) and periodontitis are common chronic diseases, which together affect almost 1 billion people worldwide. There is growing evidence suggesting a relationship between chronic inflammatory conditions such as periodontitis and PAOD. This study aims to determine an association between both entities using high quality research data and multiple phenotypes derived from an epidemiological cohort study. Design: This population-based cross-sectional cohort study included data from 3271 participants aged between 45 and 74 years enrolled in the Hamburg City Health Study (NCT03934957). Material & Methods: An ankle-brachial-index below 0.9, color-coded ultrasound of the lower extremity arteries, and survey data was used to identify participants with either asymptomatic or symptomatic PAOD. Periodontitis data was collected at six sites per tooth and included the probing depth, gingival recession, clinical attachment loss, and bleeding on probing index. Multivariate analyses using logistic regression models were adjusted for variables including age, sex, smoking, education, diabetes, and hypertension. Results: The baseline characteristics differed widely between participants neither affected by periodontitis nor PAOD vs. the group where both PAOD and severe periodontitis were identified. A higher rate of males, higher age, lower education level, smoking, diabetes, and cardiovascular disease was observed in the group affected by both diseases. After adjusting, presence of severe periodontitis (odds ratio 1.265; 97.5% CI 1.006–1.591; p = 0.045) was independently associated with PAOD. Conclusion: In this cross-sectional analysis of a prospective cohort study, an independent association between periodontitis and PAOD was revealed. The results of the current study emphasize a potential for preventive medicine in an extremely sensitive target population. Future studies should determine the underlying factors modifying the relationship between both diseases.