The Risk of Disease Progression in Peripheral Arterial Disease is Higher than Expected: A Meta-Analysis of Mortality and Disease Progression in Peripheral Arterial Disease

Contrast-Enhanced Magnetic Resonance Imaging Based T1 Mapping and Extracellular Volume Fractions Are Associated with Peripheral Artery Disease

BACKGROUND

Extracellular volume fraction (ECV), measured with contrast-enhanced magnetic resonance imaging (CE-MRI), has been utilized to study myocardial fibrosis, but its role in peripheral artery disease (PAD) remains unknown. We hypothesized that T1 mapping and ECV differ between PAD patients and matched controls.

METHODS AND RESULTS

A total of 37 individuals (18 PAD patients and 19 matched controls) underwent 3.0T CE-MRI. Skeletal calf muscle T1 mapping was performed before and after gadolinium contrast with a motion-corrected modified look-locker inversion recovery (MOLLI) pulse sequence. T1 values were calculated with a three-parameter Levenberg-Marquardt curve fitting algorithm. ECV and T1 maps were quantified in five calf muscle compartments (anterior [AM], lateral [LM], and deep posterior [DM] muscle groups; soleus [SM] and gastrocnemius [GM] muscles). Averaged peak blood pool T1 values were obtained from the posterior and anterior tibialis and peroneal arteries. T1 values and ECV are heterogeneous across calf muscle compartments. Native peak T1 values of the AM, LM, and DM were significantly higher in PAD patients compared to controls (all p < 0.028). ECVs of the AM and SM were significantly higher in PAD patients compared to controls (AM: 26.4% (21.2, 31.6) vs. 17.3% (10.2, 25.1), p = 0.046; SM: 22.7% (19.5, 27.8) vs. 13.8% (10.2, 19.1), p = 0.020).

CONCLUSIONS

Native peak T1 values across all five calf muscle compartments, and ECV fractions of the anterior muscle group and the soleus muscle were significantly elevated in PAD patients compared with matched controls. Non-invasive T1 mapping and ECV quantification may be of interest for the study of PAD.

New Horizons in Peripheral Artery Disease

Peripheral artery disease (PAD) is the lower limb manifestation of systemic atherosclerotic disease. PAD may initially present with symptoms of intermittent claudication, whilst chronic limb-threatening ischaemia (CLTI), the end stage of PAD, presents with rest pain and/or tissue loss. PAD is an age-related condition present in over 10% of those aged ≥65 in high-income countries. Guidelines regarding definition, diagnosis and staging of PAD and CLTI have been updated to reflect the changing patterns and presentations of disease given the increasing prevalence of diabetes. Recent research has changed guidelines on optimal medical therapy, with low-dose anticoagulant plus aspirin recommended in some patients. Recently published randomised trials highlight where bypass-first or endovascular-first approaches may be optimal in infra-inguinal disease. New techniques in endovascular surgery have increased minimally invasive options for ever more complex disease. Increasing recognition has been given to the complexity of patients with CLTI where a high prevalence of both frailty and cognitive impairment are present and a significant burden of multi-morbidity and polypharmacy. Despite advances in minimally invasive revascularisation techniques and reduction in amputation incidence, survival remains poor for many with CLTI. Shared decision-making is essential, and conservative management is often appropriate for older patients. There is emerging evidence of the benefit of specialist geriatric team input in the perioperative management of older patients undergoing surgery for CLTI. Recent UK guidelines now recommend screening for frailty, cognitive impairment and delirium in older vascular surgery patients as well as recommending all vascular surgery services have support and input from specialist geriatrics teams.

Polymer-based drug-eluting stent treatment extends the time to reintervention for patients with symptomatic femoropopliteal artery disease: clinical evidence and potential economic value

Aim: Use long-term follow-up data from the IMPERIAL study to determine whether drug-eluting polymer-based nitinol stent treatment can delay the time to repeat intervention for femoropopliteal artery disease and how such a delay may result in cost savings in a value-based episode of care. Patients & methods: The IMPERIAL randomized controlled trial was an international study of a paclitaxel-eluting polymer-coated stent (Eluvia, Boston Scientific, MA, USA) versus a polymer-free paclitaxel-coated stent (Zilver PTX, Cook Corporation, IN, USA) for treating lesions of the femoropopliteal arterial segment. Study patients (n = 465) had symptomatic lower limb ischemia. Safety and efficacy assessments were performed through 5 years. Mean time to first reintervention was calculated in post-hoc analysis for patients who underwent a clinically driven target lesion revascularization (CD-TLR) through 3 or 5 years following the index procedure. To simulate potential cost savings associated with differential CD-TLR burden over time, a cost-avoidance analysis using input parameters from IMPERIAL and US 100% Medicare standard analytical files was developed. Results: Among patients with a first CD-TLR through 3 years of follow-up, mean time to reintervention was 5.5 months longer (difference 166 days, 95% CI: 51, 282 days; p = 0.0058) for patients treated with Eluvia (n = 56) than for those treated with Zilver PTX (n = 30). Through the 5-year study follow-up period, CD-TLR rates were 29.3% (68/232) for Eluvia and 34.2% (39/114) for Zilver PTX (p = 0.3540) and mean time to first reintervention exceeded 2 years for patients treated with Eluvia at 737 days versus 645 days for the Zilver PTX group (difference 92 days, 95% CI: -85, 269 days; p = 0.3099). Simulated savings considering reinterventions occurring over 1 and 5 years following initial use of Eluvia over Zilver PTX were US $1,395,635 and US $1,531,795, respectively, when IMPERIAL CD-TLR rates were extrapolated to 1000 patients. Conclusion: IMPERIAL data suggest initial treatment with Eluvia extends the time patients spend without undergoing reintervention. This extension may be associated with cost savings in relevant time frames.

Predictive Value of the Naples Prognostic Score on Long-Term Outcomes in Patients with Peripheral Artery Disease Revascularized via Percutaneous Intervention

BACKGROUND

Lower extremity peripheral artery disease (PAD) is the third most common clinical manifestation of atherosclerosis after coronary artery disease and stroke. Despite successful endovascular treatment (EVT), mortality and morbidity rates still remain higher in patients with PAD. Naples prognostic score (NPS) is a novel scoring system, reflects the patient's nutritional and immunological statuses as well as systemic inflammatory responses. In this study, we aimed to investigate the relationship between NPS and long-term outcomes in patients with PAD.

METHODS

The population of this retrospective study consisted of 629 PAD patients who underwent EVT at Kafkas University Hospital between 2020 and 2023. For each patient, the NPS was calculated and then patients were divided into 3 groups based on their NPS. The primary end point of the study was the rate of major adverse cardiovascular (MACEs) and limb events (MALEs), that is, all-cause death or development of critical limb ischemia with consequent amputation.

RESULTS

Of a total of 629 patients, 62 were classified into group 0 (NPS 0), 315 into group 1 (NPS 1 or 2), and 252 into group 2 (NPS 3 or 4). The distribution of patients' baseline characteristics, angiographic features and MACEs and MALEs according to the NPS groups was analyzed. Significant adverse outcomes differences were observed among the 3 groups (P < 0.001). Multivariate logistic regression analysis revealed that age, diabetes mellitus, chronic kidney disease, lowest preprocedure ankle-brachial index, left ventricular ejection fraction and NPS (hazard ratio 1.916, 95% confidence interval [CI] 1.530-2.398, P < 0.001) were independent predictors of MACE whereas diabetes mellitus, presence of previous PAD, hemoglobin level, in-hospital acute thrombotic occlusion and NPS (odds ratio 1.963, 95% CI 1.489-2.588, P < 0.001) were independent predictors of MALE.

CONCLUSIONS

The inflammatory and nutritional state reflected by NPS levels was strongly associated with all-cause mortality and amputation after EVT in patients with PAD. Furthermore, NPS was found to be an independent predictor of these clinical outcomes.

Advancements in Omics and Breakthrough Gene Therapies: A Glimpse into the Future of Peripheral Artery Disease

Peripheral artery disease (PAD), a highly prevalent global disease, associates with significant morbidity and mortality in affected patients. Despite progress in endovascular and open revascularization techniques for advanced PAD, these interventions grapple with elevated rates of arterial restenosis and vein graft failure attributed to intimal hyperplasia (IH). Novel multiomics technologies, coupled with sophisticated analyses tools recently powered by advances in artificial intelligence, have enabled the study of atherosclerosis and IH with unprecedented single-cell and spatial precision. Numerous studies have pinpointed gene hubs regulating pivotal atherogenic and atheroprotective signaling pathways as potential therapeutic candidates. Leveraging advancements in viral and nonviral gene therapy (GT) platforms, gene editing technologies, and cutting-edge biomaterial reservoirs for delivery uniquely positions us to develop safe, efficient, and targeted GTs for PAD-related diseases. Gene therapies appear particularly fitting for ex vivo genetic engineering of IH-resistant vein grafts. This manuscript highlights currently available state-of-the-art multiomics approaches, explores promising GT-based candidates, and details GT delivery modalities employed by our laboratory and others to thwart mid-term vein graft failure caused by IH, as well as other PAD-related conditions. The potential clinical translation of these targeted GTs holds the promise to revolutionize PAD treatment, thereby enhancing patients' quality of life and life expectancy.

In the Loop: Endovascular Pedal Arch Revascularization

Advanced endovascular techniques are increasingly being utilized to treat patients with peripheral arterial disease and chronic limb-threatening ischemia to improve lower extremity arterial perfusion. In diabetic patients, pedal arch patency has been associated with improved wound healing, limb salvage, and overall survival. Pedal-plantar loop revascularization is a technique that can restore arterial inflow between the dorsal and plantar arteries of the foot. This article will describe the inframallelolar arterial anatomy and focus on imaging, percutaneous endovascular techniques, and clinical study outcomes of pedal artery interventions.

Socioeconomic factors predict successful supervised exercise therapy completion

OBJECTIVE

Supervised exercise therapy (SET) for patients with intermittent claudication (IC) can lower the risk of progression to chronic limb-threatening ischemia and amputation, while preserving and restoring functional status. Despite supporting evidence, it remains underutilized, and among those who initiate programs, attrition rates are extremely high. We hypothesize that socioeconomic factors may represent significant barriers to SET completion.

METHODS

Patients with IC referred to SET at a multi-hospital, single-institution health care system (2018-2022) from a prospectively maintained database were retrospectively analyzed. Our primary endpoint was SET program completion and graduation, defined as completion of 36 sessions. Our secondary endpoints were vascular intervention within 1 year of referral and change in ankle-brachial index (ABI). Baseline demographics were assessed using standard statistical methods. Predictors of SET graduation were analyzed using multivariable logistic regression generating adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Change in ABI was analyzed using t-test between subgroups. Reasons for attrition were tabulated. Patient Health Questionnaire-9 (PHQ-9), metabolic equivalent level, Vascular QOL, Duke Activity Status, and ABI were analyzed using paired t-tests across the entire cohort.

RESULTS

Fifty-two patients met inclusion criteria: mean age 67.85 ± 10.69 years, 19 females (36.54%), mean baseline ABI of 0.77 ± 0.16. The co-pays for 100% of patients were fully covered by primary and secondary insurance plans. Twenty-one patients (40.38%) completed SET. On multivariable analysis, residence in a ZIP code with median household income <$47,000 (aOR, 0.10; 95% CI, 0.01-0.76; P = .03) and higher body mass index (aOR, 0.81; 95% CI, 0.67-0.99; P = .04) were significant barriers to SET graduation. There were no differences in ABI change or vascular intervention within 1 year between graduates and non-graduates. Non-graduates reported transportation challenges (25.00%), lack of motivation (20.83%), and illness/functional limitation (20.83%) as primary reasons for SET attrition. Metabolic Equivalent Level (P ≤ .01) and Duke Activity Status scores (P = .04) were significantly greater after participating in a SET program.

CONCLUSIONS

Although SET participation improves lower extremity and functionality outcomes, only 40% of referred patients completed therapy in our cohort. Our findings suggest that both socioeconomic and functional factors influence the odds of completing SET programs, indicating a need for holistic pre-referral assessment to facilitate enhanced program accessibility for these populations.

High Mortality in Patients With an Ischemic Foot Ulcer Following Revascularization

Critical limb ischemia (CLI) is the advanced stage of peripheral arterial disease, which impairs blood flow to the extremities due to occlusion of arteries, in which patients suffer from ischemic pain at rest and gangrene or ulcers. It is frequently accompanied by major adverse cardiac events, resulting in exceedingly high mortality from a cardiac or cerebrovascular event in this population. Although there have been considerable amounts of novel and costly revascularization and wound dressing technology, mortality is still high. Therefore, the risk factors for such high mortality need to be addressed. This review aimed to summarize the potential risk factors for mortality in patients with CLI of the lower extremities. There are several such risk factors, including modifiable and nonmodifiable risk factors. This review further discusses some highlighted major modified risk factors, including renal failure, cardiovascular, and diabetes. The strategy of regular surveillance and modification of such risk factors in any patients with CLI should be developed.

Metabolic Syndrome and Risk of Peripheral Arterial Disease: A Systematic Review and Meta-Analysis

This systematic review aimed to evaluate metabolic syndrome as a risk factor for the development of peripheral arterial disease (PAD). We searched in four databases: (1) PubMed, (2) Web of Science, (3) Scopus, and (4) Embase until March 2021. We included cohort studies that evaluated the risk of PAD in patients with and without metabolic syndrome. Study selection, data extraction, and risk of bias analysis were performed independently by 2 authors. We used a random-effects model to conduct a meta-analysis of effect measures [hazard ratio (HR), risk ratio (RR), and odds ratio (OR)]. Individual analyses were performed according to the diagnostic criterion used for metabolic syndrome. We included 7 cohort studies with a total of 43 824 participants. Most of the studies were performed in the general adult population. The metabolic syndrome and PAD diagnostic criteria used in the individual studies were heterogeneous. Almost all studies using RR found an association between metabolic syndrome and the development of PAD (RR: 1.31; confidence interval 95%: 1.03-1.59; I 2 : 15.6%). On the other hand, almost all the studies that used HR found no association between the two variables. All studies had a low risk of bias. In conclusion, available evidence on the association between metabolic syndrome and the risk of developing PAD is inconsistent. However, given the high prevalence of risk factors that patients with metabolic syndrome have, testing to rule out PAD could be recommended. Future studies should analyze each component of the metabolic syndrome separately and according to the severity of PAD.

Endovascular Denervation for the Improvement of Limb Ischemia in Patients with Peripheral Artery Disease: A Randomized Clinical Trial

BACKGROUND

To evaluate the safety and efficacy of endovascular denervation (EDN) as an adjunct to percutaneous vascular intervention (PVI) for peripheral artery disease (PAD).

METHODS

From August 2019 to April 2021, 38 eligible patients with PAD enrolled in this study were randomly and equally assigned into 2 groups: the PVI group and the PVI + EDN group treated with EDN at the iliac and femoral arteries before PVI. The primary endpoint was the improvement in the ankle brachial index at 6 months after the procedure. The secondary endpoints were transcutaneous oxygen pressure (TcPO2), Rutherford category, numerical rating scale score, and safety.

RESULTS

The technical success rates of PVI and EDN were 100%, and no device-related or procedure-related major adverse events occurred in either group. Compared with PVI alone, PVI + EDN demonstrated a significant improvement in limb hemodynamics at 6 months (Δ ankle brachial index 0.44 ± 0.31 vs. 0.24 ± 0.15, P = 0.018). Microcirculatory perfusion of PAD was significantly better at 6 months in the PVI + EDN group (ΔTcPO2, 15.68 ± 16.72 vs. 4.95 ± 13.43, P = 0.036). The Rutherford category was significantly improved in the PVI + EDN group in comparison with the PVI group at the 3-month follow-up (100.00% vs. 68.42%, P = 0.02). The decrease in the numerical rating scale score in the PVI + EDN group was greater than that in the PVI group at 1 week following the procedure (3 [2-5] vs. 4 [4-6], P = 0.022).

CONCLUSIONS

In this single-center pilot analysis of a heterogeneous cohort of patients with PAD, PVI with EDN demonstrated a significant improvement in limb ischemia at 6 months compared with PVI alone.

Systematic review and meta-analysis comparing the autogenous vein bypass versus a prosthetic graft for above-the-knee femoropopliteal bypass surgery in patients with intermittent claudication

OBJECTIVES

According to guidelines, the autogenous saphenous vein (ASV) is the preferred conduit for femoropopliteal bypass surgery in all patients with peripheral artery disease. However, in contrast to patients with critical limb ischemia (CLI), patients with intermittent claudication (IC) only, tend to have milder disease, and thus a prosthetic graft may be as good as a vein conduit. The objective of this study was to compare patency rates of the ASV and a prosthetic graft in femoropopliteal bypass surgery in patients with IC.

METHODS

A systematic literature search was performed in the PubMed, Embase, and Cochrane databases to identify randomized controlled trials comparing prosthetic graft versus ASV in patients with IC. Articles with a mixed IC and CLI study population were included if more than 50% of the study cohort was treated for IC. Primary analysis was performed on IC patients only. Secondary analysis was performed on the mixed group. The primary endpoint was short- and long-term patency and secondary endpoints were complications, limb salvage, and mortality.

RESULTS

In total, six studies with 524 patients were included. Only two studies reported solely on patients with IC. All these patients underwent above-the-knee bypasses and average patency rates at one and 5 years were 88% and 76% vs 81% and 68% in the ASV and the PTFE groups, respectively. One and five-year patency was not statistically different between the groups (OR 5.21; 95% CI 0.60-45.36 and OR 2.10; 95% CI 0.88-5.01). In a mixed population of patients with IC and CLI (84% IC patients), 1 year patency was comparable (OR 1.40; 95% CI 0.87-2.25). However, after a follow-up of over 3 years, this mixed group had significantly higher patency rates in favour of the ASV (OR 2.06; 95 % CI 1.30-3.26). Complication and amputation rates were comparable in both groups.

CONCLUSIONS

Limited data are available for patients receiving above-the-knee femoropopliteal bypass for intermittent claudication. The ASV remains the conduit of choice for femoropopliteal bypass surgery. However, the prosthetic conduit seems a feasible alternative for patients with intermittent claudication in whom the ASV is not present or unsuitable.

[Choice of hybrid interventions for iliac-femoral arterial lesions]

OBJECTIVE

To compare the short-term and long-term outcomes of hybrid interventions after various infrainguinal reconstructions (restoration of blood flow through superficial femoral artery and pulsatile blood flow through deep femoral artery) in patients with iliac-femoral arterial disease.

MATERIAL AND METHODS

A retrospective analysis included patients after hybrid iliac-femoral interventions between 2014 and 2018. These interventions included stenting of iliac arteries and various open infrainguinal reconstructions. The first group (n=41) consisted of patients who underwent reconstruction of superficial femoral artery, the second group (n=88) - restoration of pulsatile blood flow in deep femoral artery. We analyzed the Rutherford score, perioperative complications, primary patency rates and limb salvage rates after 12 months in both groups.

RESULTS

Significant improvement (Rutherford score +3) was achieved in 28 (70%) and 14 (15.9%) patients, respectively (p<0.05). There were no significant between-group differences in the number of postoperative complications. Surgery time was longer in the first group (median 160 and 130 min, respectively, p<0.05). However, intraoperative blood loss was similar. Primary patency rates after 12 months were 82.4% and 95.1%, respectively (p=0.054). Limb salvage rates after 12 months were 94.7% and 100%, respectively (p<0.05).

CONCLUSION

This study highlights the potential advantages of restoring pulsatile blood flow through the deep femoral artery in hybrid interventions. Higher primary patency and limb salvage rates in the second group indicate better long-term outcomes after restoration of blood flow through the deep femoral artery. Further prospective studies are needed to confirm these results and determine the underlying mechanisms of differences.

An audit of secondary prevention for peripheral arterial disease in primary care - scope for improved collaboration between vascular surgery and general practitioners

BACKGROUND

Symptomatic peripheral arterial disease (PAD) is a common cause for referral from primary care to vascular surgery. Best medical therapy (BMT), encompassing anti-platelets, statins, smoking cessation, blood pressure and glycaemic control, is a cornerstone of PAD management. However, these easily modifiable risk factors are often left unaddressed between referral and clinic review.

METHODS

A prospective audit of electronic 'Healthlink' referrals by GPs to the vascular department for symptomatic PAD between July 2021 and June 2022 was performed. Referrals were individually reviewed for demographics, symptoms, medical history, smoking status and medications. An information leaflet on BMT was posted to all GP practices in the Soalta region as part of an educational intervention, with plans to re-audit after 6 months.

RESULTS

One-hundred-and-seventy referrals were analysed. The median age was 68.5 years (range 33-94) and 69% (n = 117) were male. The typical vasculopath comorbidity profile was noted. Fifty-two percent (n = 88) were referred with claudication-type pain and 25% (n = 43) with critical limb ischaemia (CLI). Twenty-eight percent (n = 33) were active smokers and 31% (n = 36) had no smoking status documented. Regarding BMT, only 34.5% (n = 40) and 52% (n = 60) were on anti-platelets and statins, respectively. Suspected CLI was not significantly associated with BMT prescription at referral (p = 0.664). Only eleven referral letters mentioned risk factor optimisation.

CONCLUSIONS

Our first-cycle results identified significant scope for improvement in community-based risk factor modification for PAD referrals. We aim to continue supporting and educating our colleagues that effective medical management can start safely in primary care and further explore the barriers preventing this.

A scoping review of female sex-related outcomes after endovascular intervention for lifestyle-limiting claudication and chronic limb-threatening ischemia

Peripheral arterial disease (PAD) is on the rise, with a growing prevalence in an aging population and increasing rates of diabetes. Chronic limb-threatening ischemia poses a significant risk of limb loss. PAD is common in females, particularly after menopause, with a 35% prevalence rate in females older than 65 years. Studies have suggested that females have inferior outcomes compared with men after endovascular revascularization for PAD. With the rising utilization of endovascular interventions for the treatment of PAD, we sought to perform a review of sex-based outcomes of peripheral endovascular interventions for the treatment of symptomatic PAD. A scoping literature review was conducted to evaluate outcomes in females patients undergoing endovascular peripheral interventions for PAD. Eligibility criteria included studies focusing on adult females with lifestyle-limiting claudication or chronic limb-threatening ischemia who underwent endovascular intervention. Various endovascular procedures were considered and outcomes of interest included mortality, amputations, reinterventions, bleeding complications, and major adverse cardiac events. A systematic search was conducted in PubMed, Embase, Web of Science, and Cochrane Library databases. Sixteen studies were included in the review. Females patients undergoing endovascular interventions were associated with bleeding complications, higher rates of reintervention, and a risk of nonfatal strokes. However, females sex was not linked to higher rates of amputation or conclusively higher mortality rates post intervention. The comprehensive scoping review reveals important sex-related disparities in outcomes after endovascular procedures for symptomatic PAD. Females patients have been reported to experience worse outcomes in terms of reinterventions and bleeding complications. These findings emphasize the need for future trials focusing specifically on females patients to develop sex-inclusive treatment recommendations for advanced PAD.

Smoking cessation: why is it a persistent problem in patients with peripheral artery disease?

Nurses play a key role in advising patients to quit smoking, especially those with long-term conditions including cardiovascular disease. Peripheral artery disease (PAD) is an increasingly prevalent condition, and is the third most common presentation of atherosclerotic disease after coronary heart disease and stroke. Smoking cessation is crucial for patients with PAD but can be very challenging. Stopping smoking reduces cardiovascular morbidity and mortality, and improves claudication symptoms in patients with PAD. Those who continue to smoke are at higher risk of disease progression, amputation, myocardial infarction and death, and have poorer therapeutic outcomes. Quitting smoking is difficult, and patients should be offered a combination of behavioural and drug therapy. Nurses can provide several interventions to help patients quit and prevent relapse. A pilot study in a large London hospital found that no smokers had been referred to smoking cessation services by their vascular clinician (although some had been referred by their GP), given brief cessation advice or told how smoking cessation was essential for vascular preservation. Many thought smoking cessation programmes would not work.

Pathology, Progression, and Emerging Treatments of Peripheral Artery Disease-Related Limb Ischemia

PURPOSE

This narrative review summarizes recent research examining treatment targets for peripheral artery disease (PAD)-related limb ischemia.

METHODS

Targeted searches of the PubMed and clinical trial registry databases were performed to identify recent findings from animal models of limb ischemia and clinical studies examining PAD progression and treatment. Ongoing clinical trials testing new treatments for PAD were also reviewed. Relevant full-text articles were retrieved and critically reviewed. Where indicated, data were tabulated and summarized in the text.

FINDINGS

Most people with PAD need treatment to improve their walking and function and limit leg pain. Currently, the available treatments of cilostazol, exercise therapy, and revascularization have several deficiencies, including limited access, poor uptake, limited efficacy, and risk of complications. Severe PAD threatens limb viability and is treated by endovascular or open surgical revascularization but is not always successful in achieving limb salvage. Research is ongoing to develop and test new therapies, including new exercise programs, drugs, stem cell treatments and RNA therapeutics, so that new and adjunctive PAD treatments can be offered. Results from multiple clinical trials are expected within the next 5 years.

IMPLICATIONS

It is envisaged that a range of new therapies for PAD will be available in the future.

Different methods of bone marrow harvesting influence cell characteristics and purity, affecting clinical outcomes

Background

Bone marrow (BM)-derived stem cells were implanted to induce angiogenesis in patients with no-option critical limb-threatening ischemia. Considering the potential for this therapy, conflicting results related to BM harvesting methods have been reported that could affect stem cell concentrations and quality.

Methods

A total of 75 patients with no-option critical limb-threatening ischemia were treated with BM implantation. For 58 patients, BM was harvested using a BM aspirate concentrate system (Harvest Technologies; group HT) with a standard aspiration needle, followed by an automated centrifugation process, to produce BM aspirate concentrate. For 17 patients, BM was harvested using the Marrow Cellution system (Aspire Medical Innovation; group MC). CD34+ cells/mL, CD117+ cells/mL, CD133+ cells/mL, CD309+ cells/mL, hematocrit, and BM purity were compared between the two BM preparations.

Results

The retrospective analysis of a subset group after adjustment for age shows that the quality of BM obtained using the Marrow Cellution system is better, in terms of purity, than the classic harvesting method before centrifugation. Harvested BM before centrifugation is characterized by a higher percentage of CD133+ cells compared with BM after centrifugation. In contrast, the MC aspirate had a larger amount of very small embryonic-like cells, as indicated by the higher percentage of CD133+, CD34+, and CD45- cells. These differences translated into an increased occurrence of leg amputations in group HT than in group MC and an increase in transcutaneous oxygen pressure in patients treated with BM aspirated using MC.

Conclusions

BM manipulation, such as centrifugation, affects the quality and number of stem cells, with detrimental consequences on clinical outcomes, as reflected by the different amputation rates between the two groups.

Gender Differences and Amputation Risk in Peripheral Artery Disease-A Single-Center Experience

Background and Objectives: Peripheral artery disease (PAD) affects both genders, but the knowledge of clinical and therapeutic aspects particular to each gender has a prognostic value, modulating the risk of amputation and helping to reduce the risk of death or the occurrence of an acute vascular event secondary to optimal management. Materials and Methods: We conducted a retrospective, descriptive study that included 652 patients with PAD who were evaluated at "St. Spiridon" Hospital's Cardiology Department and divided into two groups according to gender: women (100 cases) and men (552 cases). We evaluated demographics, anthropometric data, as well as clinical and paraclinical parameters in the two groups. Results: Men had a lower mean age (p < 0.001), higher mean BMI (p = 0.049) and were more frequent smokers. (p = 0.008). Hypercholesterolemia (p = 0.026), obesity (p = 0.009), concomitant cerebrovascular (p = 0.005) and chronic kidney disease (p = 0.046) were more common in women, while coronary artery disease (p = 0.033) was more common in men. The number of angiographic stenotic lesions (p = 0.037) is a statistically significant parameter in our study, with both genders predominantly associated with stenotic lesions. In addition, directly proportional relationships were found between smoking, uric acid, inflammatory markers, and the number of stenotic lesions and thromboses or the ankle-brachial index (ABI). In the subgroup of men, the number of stenotic and thrombosed lesions positively correlated with the ABI value (p < 0.001). The presence of more than three cardiovascular risk factors (p = 0.001) and serum triglyceride levels (p = 0.019) significantly correlated with the number of angiographically detected lesions. We applied several risk scores (PREVENT III, Finnvasc Score, or GermanVasc risk score) in our study group for prognostic purposes, without showing statistically significant differences between genders. Men, rest pain, gangrene, smoking status, the presence of more than three cardiovascular risk factors, or a serum HDL-cholesterol level below 40 mg/dL (p < 0.001 for all parameters) are independent predictors associated with amputation in our study group. Conclusions: In our study, we demonstrated that several clinical-paraclinical particularities guide the diagnosis, providing the clinician with prognostic and therapeutic tools to choose the optimal management with maximum benefits.

A Simple Predictor for Long-Term Mortality After Percutaneous Iliac Artery Intervention: Systemic Immune Inflammatory Index

BACKGROUND

Peripheral arterial disease is a common disease all over the world. Medical treatment, percutaneous invasive treatment, and operation are the considerable options. Percutaneous treatment is a valid option with a higher patency rate. Systemic immune-inflammatory index (SII) is a formula which is calculated as neutrophil count to platelet count divided into lymphocyte count. This formula demonstrates the active inflammatory state. In our study, we aimed to demonstrate the relationship with SII and the mortality, major cardiovascular events, and success rates of percutaneous treatment of iliac artery disease.

METHODS

A total of 600 patients underwent percutaneous intervention due to iliac artery disease were enrolled. The primary end point was mortality and the secondary end points were in-hospital thrombosis, restenosis, residual stenosis, and postintervention complications. The best cut-off value of SII to predict mortality was determined and the patients were divided into 2 groups, as those with higher SII values (1,073.782 <) and as those with lower SII values (1,073.782 >). Each group was evaluated in terms of clinical, laboratory, and technical aspects.

RESULTS

After exclusion criteria were applied, 417 patients were enrolled into the study. Patients with high SII values had higher rates of in-hospital thrombosis [0 (0%); 3 (2.2%), P = 0.037] and mortality [38 (13.7%); 46 (33.1%), P < 0.001]. In multivariate logistic regression analysis, chronic kidney disease [odds ratio: 4.104, 95 0.5 confidence interval: 2.250-7.487, P < 0.001] and SII [odds ratio: 3.346, 95 0.5 confidence interval: 1.982-5.649, P < 0.001] were found to be independent risk factors for mortality.

CONCLUSIONS

SII is a relatively new, simple, and effective mortality risk predictor in patients with iliac artery disease who underwent percutaneous intervention. To the best of our knowledge, our study is the first study which uses SII to predict mortality in such patient group.

Randomized clinical Trial Comparing drug Eluting Stent Zilver PTX® Versus Bare Metal Stent Zilver Flex® for Treatment of Lesions in Femoral and Popliteal Arteries in Chronic Limb Threatening Ischemia

OBJECTIVE

Drug eluting stents (DES) might improve the results of stenting in the femoropopliteal (FP) segment, but randomized data between DES and BMS in the treatment of patients with chronic limb threatening ischemia (CLTI) is lacking. The aim of this study was to perform a randomized comparison, between DES and bare metal stent (BMS) implantation in a subgroup of CLTI patients with lesions in the superficial femoral artery (SFA) and the P1-P2 portion of the popliteal artery.

METHODS

Patients presenting with CLTI scheduled for endovascular treatment of FP lesions were randomly assigned by blinded envelopes 1:1 in a single blinded, parallel group design to DES or BMS after lesion crossing. Primary endpoints were target lesion revascularization (TLR) at 12 and 24 months and primary patency at 12 and 24 months. Secondary endpoints were technical success (TS), clinical success, secondary patency at 12 and 24 months, limb salvage, serious adverse events (SAE) at 24 month and survival at five years.

RESULTS

A total of 48 CLTI patients and 49 limbs, were enrolled, 22 in the BMS group and 27 in the DES group. Demographics, comorbidities, and Rutherford class were similar in both treatment arms. The overall rate of total occlusions was 96% and the corresponding overall median lesion length was 240 mm. No patients were lost to follow up. No significant differences were detected between groups regarding TLR and primary patency. The overall primary patency at 12 and 24 months was 42.9% and 36.7% respectively and the overall freedom from TLR was 67.3% and 61.2% respectively. The results in the two groups were also similar regarding secondary outcomes.

CONCLUSIONS

This single centre, randomized study could not demonstrate superiority of DES compared to BMS when treating long FP lesions in patients with CLTI but was limited by insufficient patient inclusion.

Sex-Based Differences in Clinical Characteristics and Outcomes among Patients with Peripheral Artery Disease: A Retrospective Analysis

Peripheral arterial disease (PAD) is a prevalent medical condition associated with high mortality and morbidity rates. Despite the high clinical burden, sex-based differences among PAD patients are not well defined yet, in contrast to other atherosclerotic diseases. This study aimed to describe sex-based differences in clinical characteristics and outcomes among hospitalized patients affected by PAD. This was a retrospective study evaluating all patients with a diagnosis of PAD admitted to the Emergency Department from 1 December 2013 to 31 December 2021. The primary endpoint of the study was the difference between male and female PAD patients in cumulative occurrence of Major Adverse Cardiovascular Events (MACEs) and Major Adverse Limb Events. A total of 1640 patients were enrolled. Among them, 1103 (67.3%) were males while females were significantly older (median age of 75 years vs. 71 years; p =< 0.001). Females underwent more angioplasty treatments for revascularization than men (29.8% vs. 25.6%; p = 0.04); males were treated with more amputations (19.9% vs. 15.3%; p = 0.012). A trend toward more MALEs and MACEs reported in the male group did not reach statistical significance (OR 1.27 [0.99-1.64]; p = 0.059) (OR 0.75 [0.50-1.11]; p = 0.153). However, despite lower extremity PAD severity seeming similar between the two sexes, among these patients males had a higher probability of undergoing lower limb amputations, of cardiovascular death and of myocardial infarction. Among hospitalized patients affected by PAD, even if there was not a sex-based significant difference in the incidence of MALEs and MACEs, adverse clinical outcomes were more common in males.

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.

Comparison of the oxidative profiles before and after revascularization in peripheral arterial disease: a pilot study

Reactive and highly reactive oxygen species (ROS and hROS) produced by white blood cells are essential for innate immunity; however, they may cause oxidative stress in the host. We developed systems for simultaneously monitoring ROS and hROS, i.e., superoxide radicals (O2•-) and hypochlorite ions (OCl-) secreted from stimulated white blood cells in a few microliters of whole blood. We previously reported on the evaluation of healthy volunteers' blood using the developed system; however, whether patients' blood can be assessed remains unclear. Here, we report a pilot study of 30 cases (28 patients) with peripheral arterial disease, in whom we measured the ROS and hROS levels before and approximately one month after endovascular treatment (EVT) using the system (CFL-H2200) that we developed. At approximately the same time points, physiological indices of blood vessels, oxidative stress markers, and standard clinical parameters in the blood were also monitored. The ankle-brachial index, a diagnostic tool for peripheral arterial disease, was significantly improved after EVT (p<0.001). The ROS-hROS ratio, low-density lipoprotein cholesterol, and hematocrit levels were decreased after EVT (p<0.05), while triglyceride and lymphocyte levels were increased after EVT (p<0.05). The correlations between the study parameters were also analyzed.

A modern day perspective on smoking in peripheral artery disease

Peripheral artery disease (PAD) is associated with increased risk of cardiovascular morbidity and mortality, poor functional status, and lower quality of life. Cigarette smoking is a major preventable risk factor for PAD and is strongly associated with a higher risk of disease progression, worse post-procedural outcomes, and increased healthcare utilization. The arterial narrowing due to atherosclerotic lesions in PAD leads to decreased perfusion to the limbs and can ultimately cause arterial obstruction and limb ischemia. Endothelial cell dysfunction, oxidative stress, inflammation, and arterial stiffness are among the key events during the development of atherogenesis. In this review, we discuss the benefits of smoking cessation among patients with PAD and the use of smoking cessation methods including pharmacological treatment. Given that smoking cessation interventions remain underutilized, we highlight the importance of incorporating smoking cessation treatments as part of the medical management of patients with PAD. Regulatory approaches to reduce the uptake of tobacco product use and support smoking cessation have the potential to reduce the burden of PAD.

Below-the-Knee Stents and Scaffolds: A Comprehensive Review

Below-the-knee intervention of chronic limb-threatening ischemia is an area of increasing interest. Due to lower morbidity and possibly better clinical outcomes, endovascular techniques have become increasingly important in this patient population many of who have limited surgical options. This article serves as a review of existing stent and scaffolding devices utilized for infrapopliteal disease. The authors will additionally discuss current indications and review studies that are investigating novel materials used in treating infrapopliteal arterial disease.

Combined Evaluation of Arterial Stiffness and Blood Pressure Promotes Risk Stratification of Peripheral Arterial Disease

Background

Previous studies have reported the separate association of arterial stiffness (AS) and blood pressure with peripheral arterial disease (PAD).

Objectives

The aim of this study was to investigate the risk stratification capacity of AS on incident PAD beyond blood pressure status.

Methods

A total of 8,960 participants from Beijing Health Management Cohort were enrolled at the first health visit between 2008 and 2018 and then followed until the incidence of PAD or 2019. Elevated AS was defined as brachial-ankle pulse-wave velocity (baPWV) >1,400 cm/s, including moderate stiffness (1,400 ≤ baPWV <1,800 cm/s) and severe stiffness (baPWV ≥1,800 cm/s). PAD was defined as ankle-brachial index <0.9. A frailty Cox model was used to calculate the HR, integrated discrimination improvement, and net reclassification improvement.

Results

During follow-up, 225 participants (2.5%) developed PAD. After adjusting for confounding factors, the highest risk for PAD was observed in the group with elevated AS and blood pressure (HR: 2.253; 95% CI: 1.472-3.448). Among participants with ideal blood pressure and those with well-controlled hypertension, PAD risk was still significant for severe AS. The results remained consistent in multiple sensitivity analyses. In addition, baPWV significantly improved the predictive capacity for PAD risk beyond systolic and diastolic blood pressures (integrated discrimination improvement 0.020 and 0.190, net reclassification improvement 0.037 and 0.303).

Conclusions

This study suggests the clinical importance of combined evaluation and control of AS and blood pressure for the risk stratification and prevention of PAD.

Relationship between Lower Extremity Peripheral Arterial Disease and Mild Cognitive Impairment in Hemodialysis Patients

Background: The link between arterial stiffness and mild cognitive impairment (MCI) in patients on hemodialysis (HD) has been receiving increased attention. The purpose of this study was to investigate the relationship between cognitive function and ankle brachial index (ABI) and toe brachial index (TBI) values in patients on hemodialysis. Of the 100 participants (mean age: 67.9 years; average history of hemodialysis: 7.3 years). Of these, 46.0% had MCI. The MoCA-J scores were significantly higher in the ABI ≥ 1.06 group. However, the MoCA-J scores divided into the two groups according to the TBI cutoff value were not significantly different. In a multiple regression model with the MoCA-J scores as the objective variable, the ABI was a significantly associated factor. This study indicates that a low ABI might be associated with MCI.

The benefits of a centralized remote surveillance program for vascular patients

OBJECTIVE

We aimed to assess the clinical and financial utility of a centralized remote surveillance program for vascular patients compared with traditional outpatient follow-up.

METHODS

In 2014, the Royal Adelaide Hospital Department of Vascular Surgery introduced a centralized remote surveillance program where suitable patients were monitored by remote imaging in lieu of traditional outpatient appointments (OPAs). Surveillance imaging was performed at a site local to the patient and was reviewed centrally by a dedicated surveillance nurse. We undertook a 5-year retrospective analysis of the program's prospectively maintained database since its inception. Costs for inpatient admissions and OPAs were retrieved from hospital financial databases. The surveillance database and electronic patient records were analyzed for number and outcome of surveillance scans, interventions, and OPAs. Additional savings in travel distance, fuel costs, and CO₂ emissions were also calculated.

RESULTS

Over 5 years, 1262 patients underwent a mean of four scans per patient. A total of 3718 OPAs were saved, approximating 930 hours of clinic and consultant time, with associated savings of Australian (A)$1,524,900 (United States [US]$ 1,065,684) over 5 years (A$ 304,980 [US$ 213,137] per year). For every OPA avoided, each patient saved 197 km travel and A$87 (US$ 61) fuel costs, with an associated 115 kg of CO₂ emissions saved. Over 5 years, this equated to savings of 248,173 km travel, A$ 110,136 (US$ 76,969) fuel costs, and 146 tons of CO₂ emissions. A total of 134 surveillance-detected pathologies (10.6%) required intervention, a further 28 despite surveillance (2.2%), and three following surveillance cessation (0.2%). Subgroup analysis demonstrated that interventions despite surveillance were three times more expensive and incurred four times longer admissions than those due to surveillance.

CONCLUSIONS

Remote vascular surveillance, particularly applicable in our current COVID-19 pandemic climate, is associated with quantifiable financial, clinical, patient, and environmental beneficial outcomes and can be safely delivered to populations spanning large geographical areas such as those in Australia.

Increased Medicaid eligibility of Affordable Care Act: Evidence of improved outcomes for patients with peripheral artery disease

Peripheral artery disease (PAD) is a debilitating disease that disproportionately affects people of low socioeconomic status and racial minority individuals. These groups also tend to have lower rates of revascularization and worse outcomes, including higher rates of major amputation. In 2010, the Affordable Care Act (ACA) was signed into law, providing better opportunities for health care access to millions of uninsured Americans, although the implementation of different components started at a later date. Political issues led to uneven adaptation by states of the different ACA components. In states that adopted Medicaid expansion under the ACA, similar to that under the Massachusetts Health Care Reform Law of 2006, patients of low socioeconomic status and racial minority patients gained better access to health care. This review article will examine the disparities that exist in peripheral artery disease outcomes, as well as the effects of the ACA and Medicaid expansion on revascularization, limb salvage, and major amputation rates.

Lower-limb peripheral arterial disease and amputations in people with diabetes: Risk factors, prognostic value and management

Lower-limb peripheral arterial disease (PAD), is a common manifestation of systemic atherosclerosis, resulting from a partial or complete obstruction of at least one lower-limb arteries. PAD is a major endemic disease with an excess risk of major cardiovascular events and death. It also leads to disability, high rates of lower-limb adverse events and non-traumatic amputation. In patients with diabetes, PAD is particularly frequent and has a worse prognosis than in patients without diabetes. The risk factors of PAD are comparable to those for cardiovascular disease. The ankle-brachial index is usually recommended to screen PAD despite its limited performance in patients with diabetes, affected by the presence of peripheral neuropathy, medial arterial calcification, incompressible arteries and infection. Toe brachial index and toe pressure emerge as alternative screening tools. The management of PAD requires strict control of cardiovascular risk factors including diabetes, hypertension and dyslipidaemia, the use of antiplatelet agents and lifestyle management, to reduce cardiovascular adverse events, but few randomized controlled trials have evaluated the benefits of these treatments in PAD. Several advances have been achieved in endovascular and surgical revascularization procedures, with obvious improvement in PAD prognosis. Further studies are required to increase our understanding of the pathophysiology of PAD and to evaluate the interest of different therapeutic strategies in the occurrence and progression of PAD in patients with diabetes. Here, we present a narrative and contemporary review to synthesize the key epidemiology findings, screening and diagnosis methods, and major therapeutic advances regarding PAD in patients with diabetes.

MetfOrmin BenefIts Lower Extremities with Intermittent Claudication (MOBILE IC): randomized clinical trial protocol

BACKGROUND

Peripheral artery disease (PAD) affects over 230 million people worldwide and is due to systemic atherosclerosis with etiology linked to chronic inflammation, hypertension, and smoking status. PAD is associated with walking impairment and mobility loss as well as a high prevalence of coronary and cerebrovascular disease. Intermittent claudication (IC) is the classic presenting symptom for PAD, although many patients are asymptomatic or have atypical presentations. Few effective medical therapies are available, while surgical and exercise therapies lack durability. Metformin, the most frequently prescribed oral medication for Type 2 diabetes, has salient anti-inflammatory and promitochondrial properties. We hypothesize that metformin will improve function, retard the progression of PAD, and improve systemic inflammation and mitochondrial function in non-diabetic patients with IC.

METHODS

200 non-diabetic Veterans with IC will be randomized 1:1 to 180-day treatment with metformin extended release (1000 mg/day) or placebo to evaluate the effect of metformin on functional status, PAD progression, cardiovascular disease events, and systemic inflammation. The primary outcome is 180-day maximum walking distance on the 6-min walk test (6MWT). Secondary outcomes include additional assessments of functional status (cardiopulmonary exercise testing, grip strength, Walking Impairment Questionnaires), health related quality of life (SF-36, VascuQoL), macro- and micro-vascular assessment of lower extremity blood flow (ankle brachial indices, pulse volume recording, EndoPAT), cardiovascular events (amputations, interventions, major adverse cardiac events, all-cause mortality), and measures of systemic inflammation. All outcomes will be assessed at baseline, 90 and 180 days of study drug exposure, and 180 days following cessation of study drug. We will evaluate the primary outcome with linear mixed-effects model analysis with covariate adjustment for baseline 6MWT, age, baseline ankle brachial indices, and smoking status following an intention to treat protocol.

DISCUSSION

MOBILE IC is uniquely suited to evaluate the use of metformin to improve both systematic inflammatory responses, cellular energetics, and functional outcomes in patients with PAD and IC.

TRIAL REGISTRATION

The prospective MOBILE IC trial was publicly registered (NCT05132439) November 24, 2021.

Cost-effectiveness analysis of screening for peripheral artery disease in patients with coronary artery disease in China: A Markov model

BACKGROUND

The innovative pharmacological combination of low-dose rivaroxaban plus aspirin provides clinicians with an ideal opportunity to intensify the medical treatment of patients with coronary artery disease (CAD) and comorbid peripheral artery disease (PAD). We aimed to determine the cost-effectiveness of PAD screening using the ankle-brachial index (ABI) test in patients with CAD (with rivaroxaban administered if the PAD screening was positive) compared with no-screening strategy in China.

METHODS

A Markov decision model using a 1-month cycle was developed to simulate the 25-year effectiveness and cost of PAD screening on 75-year-old patients with CAD in China, evaluating the quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). One-way, two-way, and probabilistic sensitivity analyses were conducted to assess the impact of variations in the key parameters for ICERs.

RESULTS

Our model found an incremental cost of RMB4,959 (US$740) and an incremental QALY of 0.054 after one-time ABI screening, leading to an ICER of RMB91,936 (US$13,717) per QALY gained over a 25-year period. The reduction in all-cause mortality related to rivaroxaban and its cost were the factors most affecting the ICER. The screening would become cost-effective by decreasing the monthly cost of rivaroxaban to RMB184.5 (US$27.5) or by using domestic-brand rivaroxaban according to the threshold of a willingness to pay RMB72,447 (US$10,809) per QALY gained.

CONCLUSIONS

Our study demonstrated that ABI screening for PAD to decide on low-dose rivaroxaban administration was not cost-effective for patients with CAD in China. Nevertheless, policy-guided cost changes for domestic-brand rivaroxaban could easily resolve this issue.

Circulating Amino Acids and Risk of Peripheral Artery Disease in the PREDIMED Trial

Effective prevention and risk prediction are important for peripheral artery disease (PAD) due to its poor prognosis and the huge disease burden it produces. Circulating amino acids (AA) and their metabolites may serve as biomarkers of PAD risk, but they have been scarcely investigated. The objective was to prospectively analyze the associations of baseline levels of plasma AA (and their pathways) with subsequent risk of PAD and the potential effect modification by a nutritional intervention with the Mediterranean diet (MedDiet). A matched case-control study was nested in the PREDIMED trial, in which participants were randomized to three arms: MedDiet with tree nut supplementation group, MedDiet with extra-virgin olive oil (EVOO) supplementation group or control group (low-fat diet). One hundred and sixty-seven PAD cases were matched with 250 controls. Plasma AA was measured with liquid chromatography/mass spectrometry at the Broad Institute. Baseline tryptophan, serine and threonine were inversely associated with PAD (OR_{for 1 SD increase} = 0.78 (0.61-0.99); 0.67 (0.51-0.86) and 0.75 (0.59-0.95), respectively) in a multivariable-adjusted conditional logistic regression model. The kynurenine/tryptophan ratio was directly associated with PAD (OR_{for 1 SD increase} = 1.50 (1.14-1.98)). The nutritional intervention with the MedDiet+nuts modified the association between threonine and PAD (p-value interaction = 0.018) compared with the control group. However, subjects allocated to the MedDiet+EVOO group were protected against PAD independently of baseline threonine. Plasma tryptophan, kynurenine/tryptophan ratio, serine and threonine might serve as early biomarkers of future PAD in subjects at a high risk of cardiovascular disease. The MedDiet supplemented with EVOO exerted a protective effect, regardless of baseline levels of threonine.

The Impact of Diabetes in Intermittent Claudication: A Prospective Cohort Study

The aim of this study was to determine the lower-limb outcome in patients with intermittent claudication (IC) and to identify predictors for deterioration. This study employed a prospective observational cohort single-centre design. One hundred fifty patients with IC attending a vascular surgery unit for the first time were recruited. Lower limb perfusion was assessed utilising ankle brachial index (ABI) measures, toe-brachial index (TBI) measures, Doppler waveform analysis and the walking impairment questionnaire. Follow-up was conducted after 1 year and 2 years following recruitment to assess haemodynamic parameters, symptom severity and outcome. Recruited participants had a mean age of 69.7 (±9.3) years, BMI 27.8(±4.2) and 79.3% were men. Significant haemodynamic decline (decline in ABPI by ≥0.15 and/or decline in TBPI by ≥0.1) occurred in 50.6% of the cohort within 2 years of whom 23.3% developed chronic limb threatening ischaemia (CLTI) with rest pain and/or tissue loss. Baseline ABPI, ABPI ≤ 0.5, TBPI ≤ 0.39, infrapopliteal artery (IPA) disease and high Haemoglobin A1c were identified as significant predictors for deterioration to CLI. (P < .05, binomial logistic regression). Patients with IC are at a high risk of developing CLTI within 2 years. Risk of lower limb adverse events is tripled in patients with IPA disease, low ankle and toe pressures and poorly controlled diabetes. Early identification of those at high risk for early deterioration may justify a paradigm shift in the management of this subgroup.

Lipoprotein (a) and long-term outcome in patients with peripheral artery disease undergoing revascularization

BACKGROUND AND AIMS

Despite low LDL-C goals, the residual risk for further cardiovascular (CV) events in patients with peripheral artery disease (PAD) remains high. Lipoprotein (a) (Lp(a)) is a known risk factor for PAD incidence, but little is known regarding the outcome in patients with symptomatic PAD. Thus, this study investigates Lp(a) and CV mortality in PAD after endovascular repair.

METHODS

A total of 1222 patients with PAD in two cohorts according to Lp(a) assay in nmol/L (n = 964, Lip-LEAD-A) or mg/dl (n = 258, Lip-LEAD-B) were followed up for 4.3 (IQR 3.0-5.6) or 7.6 (IQR 3.2-8.1) years. Lp(a) was measured before endovascular repair for either intermittent claudication (IC) or critical limb ischemia (CLI). Outcome information was obtained from the federal death registry.

RESULTS

In Lip-LEAD-A, 141 CV-deaths occurred (annual calculated CV-death rate 3.4%), whereas 64 CV-deaths were registered in Lip-LEAD-B (annual calculated CV-death rate 3.3%). After adjustment for traditional CV risk factors Lp(a) was neither associated with outcome in Lip-LEAD-A (highest tertile HR 1.47, 95%CI [0.96-2.24]) nor in Lip-LEAD-B (highest tertile HR 1.34 [0.70-2.58]). Subanalyses for IC (HR 1.37 [0.74-2.55]; HR 1.10 [0.44-2.80], CLI (HR 1.55 [0.86-2.80], HR 3.01 [0.99-9.10]), or concomitant coronary artery disease (CAD; HR 1.34 [0.71-2.54]; HR 1.21 [0.46-3.17]) failed to show a significant association between Lp(a) and CV-mortality.

CONCLUSIONS

In this large-scale cohort of symptomatic PAD no association of elevated Lp(a) with CV mortality was found over a median observation period of 5 years. Thus, an even longer study including asymptomatic patients is warranted.

ACR Appropriateness Criteria® Lower Extremity Arterial Claudication-Imaging Assessment for Revascularization: 2022 Update

Arterial claudication is a common manifestation of peripheral artery disease. This document focuses on necessary imaging before revascularization for claudication. Appropriate use of ultrasound, invasive arteriography, MR angiography, and CT angiography are discussed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Long-Term Results of the Treatment of Patients With Chronic Ischemia of the Lower Limbs in Combination With Ischemic Heart Disease

Aim      To compare long-term outcomes of x-ray endovascular (percutaneous coronary intervention, PCI, and lower limb angioplasty with stent placement, LLA; group 1) and combination treatments (PCI and open LLA surgery; group 2) in patients with chronic lower limb ischemia (CLLI) associated with ischemic heart disease (IHD).

Material and methods  This retrospective study has been conducted in the Vishnevsky National Medical Research Center of Surgery since 2019. The study includes 92 patients with stage 2B CLLI associated with IHD who were managed from January 1, 2017 through December 31, 2020. Long-term outcomes were evaluated in 76 (82.6 %) patients. The endpoint was severe cardiovascular complications (CVC), including death, myocardial infarction, and acute cerebrovascular disease (ACVD).

Results In group 1 during the long-term period, 1 (2.7%) fatal outcome due to pneumonia was observed. In group 2, 4 (10 %) patients died: 1 (2.5 %) patient due to ACVD, 1 (2.5 %) patient due to progression of oncological process, and 2 2 (5 %) patients due to COVID-19. Also, 2 (5.5 %) and 1 (2.5 %) cases of acute coronary syndrome (ACS) were observed in groups 1 and 2, respectively (p=0.61).

Conclusion      In the x-ray endovascular (group1) and the combination (group 2) intervention groups, lethal outcomes due to myocardial infarction were absent. This fact confirms the importance of PCI in patients with CLLI for prevention of possible ACS in the long-term. Both therapeutic tactics in managing CLLI patients with IHD demonstrated high safety and clinical efficacy during the hospital and long-term periods and can be extensively used in routine clinical practice.

Secular trends in the epidemiologic patterns of peripheral artery disease and risk factors in China from 1990 to 2019: Findings from the global burden of disease study 2019

Background

An understanding of the epidemiologic patterns of peripheral artery disease is essential in public health policy-making. We aimed to assess secular trends in the epidemiologic patterns and risk factors of peripheral artery disease from 1990 to 2019 in China.

Materials and methods

We extracted data on prevalence, incidence, death, and disability-adjusted life years (DALYs) due to peripheral artery disease from the Global Burden of Disease study 2019. In addition, risk factors for peripheral artery disease were reported.

Results

The age-standardized prevalence of peripheral artery disease significantly increased from 1330.42 to 1423.78 per 100,000 population, with an average annual percentage change (AAPC) of 0.16 [95% confidence interval (CI), 0.07 to 0.24] from 1990 to 2019 in China. In addition, the age-standardized mortality rate significantly increased, with an AAPC of 0.62 (95% CI, 0.54 to 0.7), contrasting with the significantly declining trend in age-standardized DALYs (AAPC, −0.45; 95% CI, −0.52 to −0.39) between 1990 and 2019. The age-standardized prevalence was almost three times higher in females than males [2022.13 (95% CI: 1750 to 2309.13) vs. 744.96 (95% CI: 644.62 to 850.82) per 100,000 population] in 2019. The age-specific incidence significantly increased in individuals aged 40–44, 45–49, 50–54, 55–59, and 60–64 years groups but decreased in 70–74, 75–79, and 80–84 years groups. The age and period effects showed that the relative risks of incident peripheral artery disease increased with age and time. The cohort assessment showed that the incidence decreased in successive birth cohorts. Smoking was identified as the risk factor that contributed the most to age-standardized DALYs of peripheral artery disease in 2019.

Conclusion

The burden of peripheral artery disease showed unexpected patterns that varied by age, sex, and year in China. More attention should be given to addressing the increasing incidence among middle-aged individuals and mortality among males.

Volumetric Flow Assessment in Extracranial Arteries in Patients with 70-99% Internal Carotid Artery Stenosis

Background: Cerebral blood flow (CBF) can be related to the risk of occurrence of neurological symptoms. Well-developed collateral circulation is a good prognostic factor in patients with cerebrovascular disease. Understanding the mechanisms of collateral circulation may be important in the diagnosis, treatment, and monitoring in this group of patients. The aim of this study covered the assessment of CBF in patients with 70−99% Internal carotid artery (ICA) stenosis, focusing on the circulation pathways and flow volume in extracranial arteries. Materials and methods: 53 patients with 70−99% ICA stenosis (mean age 73.4 ± 7 years old; 17 female, mean age 73.9 ± 7.5 years old; 36 male, mean age 73.2 ± 6.8 years old) were included in the study. In all patients a Doppler ultrasound (DUS) examination, measuring blood flow volume in the internal carotid artery (ICA), external carotid artery (ECA), and vertebral artery (VA), was performed. The cerebral blood flow (CBF) was compared to the previously reported CBF values in the healthy population > 65 years old. Results: Among the study groups three subgroups with flow differences were identified: patients with elevated CBF (significant volumetric flow compensation—26/53, 49%), patients with CBF similar to (mild compensation—17/53, 32%), and patients with CBF lower than (no compensation—10/53, 19%) the healthy, equally aged population. The percentage of patients with significant volumetric flow compensation was the highest in age groups 65−69 years old (62.5%) and >80 years old (60%). In the oldest age group (>80 years old) no patients without flow compensation (0%) were observed. The level of compensation depends on the number of the arteries with compensatory increased flow. In patients with significant volumetric flow compensation, the compensatory increased flow was observed, on average, in 3.31 arteries, in the mild compensation group—in 2.18 arteries, and in the no compensation group only in 1 artery. ICA plays the most important role in the volumetric flow compensation—the increase in the flow volume, in comparison to the reference values, was between 116.7 mL/min and 251.9 mL/min (in the ECA 57.6 mL/min−110.4 mL/min; in the VA 73.9 mL/min−104.9 mL/min). The relative flow increase was highest in the VA: 215−246%, then in the ECA: 163−206%, and finally in the ICA: 148.6−192%. The increased flow was most commonly observed in the VA—57 arteries, in second place in the ECA—42 arteries, and ICA—31 arteries. In patients with unilateral ICA stenosis, the volumetric flow increase was stated more frequently in the ipsilateral ECAs then in the contralateral ones (23 vs. 14). In the VA the opposite tendency was observed (29 contralateral vs. 23 ipsilateral). The ability of volumetric flow compensation decreased significantly with increasing age. Conclusions: Understanding the mechanisms of collateral circulation and their assessment in Doppler ultrasonography may provide a novel and easily accessible tool of identifying and monitoring patients with cerebrovascular disease.

Association between platelet distribution width and peripheral arterial disease in elderly patients

Summary: Background: The prevalence of peripheral arterial disease (PAD) increases with age. Platelet activation has been linked to PAD. Platelet distribution width (PDW) is a measure of platelet function. This study aimed to investigate the relationship between PAD and PDW in elderly patients. Patients and methods: A total of 416 elderly patients in Fujian Provincial Hospital between January 1, 2018 and June 30, 2019 were enrolled. PAD was diagnosed when the ankle-brachial index (ABI) was below 0.9. Multivariate logistic regression analysis was used to examine the association between PDW and PAD. ROC curves and AUC were used to assess the diagnostic value. Results: Compared to patients without PAD, PDW was higher in patients with PAD (PAD vs. subjects without PAD, 13.19±2.24% vs. 11.52±1.39%, p<0.001). PDW was associated with an increased OR of PAD (OR: 1.667, 95% CI: 1.462–1.901, p<0.001). After adjusting for potential confounding factors, the OR changed to 1.821 (95% CI: 1.535–2.114, p<0.001). This association appeared to be more prominent in females than males (females vs. males, OR: 2.294, 95% CI: 1.556–3.381 vs. OR: 1.695, 95% CI: 1.404–2.047, p<0.001). The AUC area was 0.760 (95% CI: 0.682–0.837) for females and 0.689 (95% CI: 0.627–0.752) for males. Both cut-off values had high specificity (females vs. males, 95% vs. 100%). Conclusions: PDW was higher in elderly patients with PAD than in subjects without PAD, and the association between PDW and PAD persisted after adjusting for confounding factors.

A Proinflammatory Diet Is Associated with Higher Risk of Peripheral Artery Disease

Peripheral arterial disease (PAD) has a strong relationship with inflammation. However, it is unclear whether the dietary inflammatory potential is associated with PAD. We aimed to address this knowledge gap. The dietary inflammatory index (DII) was obtained using a 24-h dietary recall interview for each individual. Logistic regression models and restricted cubic spline were performed to assess the relationship of DII with the prevalence of PAD. In addition, Spearman correlation analysis and subgroup analysis were also undertaken. In total, 5840 individuals from the 1999–2004 National Health and Nutrition Examination Survey (NHANES) were enrolled in our study. Participants in higher DII quartile tended to have higher rates of PAD. The increase in DII scores showed a positive association with PAD after fully multivariate adjustment (OR (odds ratios) = 1.094, 95% confidence interval (CI): 1.022–1.171). The multivariable-adjusted OR and 95% CI of the highest DII index quartile compared with the lowest quartile was 1.543 (95% CI: 1.116–2.133). Subgroup analysis demonstrated that the positive association between DII and PAD was persistent across population subgroups. In conclusion, we report that a proinflammatory dietary pattern is related to a higher risk of developing PAD among US adults.

Open Proximal Endarterectomy with Retrograde Access and Stenting: A Novel Technique for Lower Extremity Revascularization

BACKGROUND

Treatment of chronic limb threatening ischemia (CLTI) poses a significant clinical challenge despite recent medical advancements. Chronic total occlusion (CTO) lesions make endovascular approaches to CLTI particularly challenging. Open proximal exposure with retrograde access and stenting (OPERAS) aims to solve this challenge through retrograde subintimal crossing of a CTO with direct visualization of proximal re-entry into the true lumen. We describe this novel technique and present its efficacy in eight patients.

METHODS

We conducted a retrospective case series at a single tertiary academic center. Data for patients who received OPERAS intervention included demographics, peri-operative details, and follow-up information. Statistical analysis was performed on length of stay, major post-operative complications, further intervention, clinical progression at 1 year, and amputation-free survival at 1 year. Immediate technical failure (ITF) and limb-based patency (LBP) at 1 year were calculated.

RESULTS

Nine limbs underwent OPERAS between January 2019 and March 2020. Inflow was achieved with common femoral artery endarterectomy. All limbs underwent balloon angioplasty and stenting of the SFA, and seven underwent the same procedure in the popliteal artery. ITF was 0% for all nine cases. There were no major post-operative complications, and ankle-brachial index significantly improved pre-and post-operatively (P < .001). Eight limbs (88.9%) sustained amputation-free survival at 1 year, and overall LBP was 67% at 1 year.

CONCLUSION

Our study presents a hybrid revascularization option to address severe, anatomically complex limbs (GLASS III) that lack a single autogenous conduit for open surgical revascularization. OPERAS addresses a main point of technical failure of subintimal techniques by directly visualizing the wire in the true lumen. Our data suggest that OPERAS can be effective to: (1) improve technical success of luminal re-entry following a subintimal approach; (2) address inflow concurrently with severe femoropopliteal disease; and (3) can be utilized when distal tissue loss is involved.

How the First Year of the COVID-19 Pandemic Impacted Patients' Hospital Admission and Care in the Vascular Surgery Divisions of the Southern Regions of the Italian Peninsula

Background: To investigate the effects of the COVID-19 lockdowns on the vasculopathic population. Methods: The Divisions of Vascular Surgery of the southern Italian peninsula joined this multicenter retrospective study. Each received a 13-point questionnaire investigating the hospitalization rate of vascular patients in the first 11 months of the COVID-19 pandemic and in the preceding 11 months. Results: 27 out of 29 Centers were enrolled. April-December 2020 (7092 patients) vs. 2019 (9161 patients): post-EVAR surveillance, hospitalization for Rutherford category 3 peripheral arterial disease, and asymptomatic carotid stenosis revascularization significantly decreased (1484 (16.2%) vs. 1014 (14.3%), p = 0.0009; 1401 (15.29%) vs. 959 (13.52%), p = 0.0006; and 1558 (17.01%) vs. 934 (13.17%), p < 0.0001, respectively), while admissions for revascularization or major amputations for chronic limb-threatening ischemia and urgent revascularization for symptomatic carotid stenosis significantly increased (1204 (16.98%) vs. 1245 (13.59%), p < 0.0001; 355 (5.01%) vs. 358 (3.91%), p = 0.0007; and 153 (2.16%) vs. 140 (1.53%), p = 0.0009, respectively). Conclusions: The suspension of elective procedures during the COVID-19 pandemic caused a significant reduction in post-EVAR surveillance, and in the hospitalization of asymptomatic carotid stenosis revascularization and Rutherford 3 peripheral arterial disease. Consequentially, we observed a significant increase in admissions for urgent revascularization for symptomatic carotid stenosis, as well as for revascularization or major amputations for chronic limb-threatening ischemia.

Therapeutic angiogenesis-based strategy for peripheral artery disease

Peripheral artery disease (PAD) poses a great challenge to society, with a growing prevalence in the upcoming years. Patients in the severe stages of PAD are prone to amputation and death, leading to poor quality of life and a great socioeconomic burden. Furthermore, PAD is one of the major complications of diabetic patients, who have higher risk to develop critical limb ischemia, the most severe manifestation of PAD, and thus have a poor prognosis. Hence, there is an urgent need to develop an effective therapeutic strategy to treat this disease. Therapeutic angiogenesis has raised concerns for more than two decades as a potential strategy for treating PAD, especially in patients without option for surgery-based therapies. Since the discovery of gene-based therapy for therapeutic angiogenesis, several approaches have been developed, including cell-, protein-, and small molecule drug-based therapeutic strategies, some of which have progressed into the clinical trial phase. Despite its promising potential, efforts are still needed to improve the efficacy of this strategy, reduce its cost, and promote its worldwide application. In this review, we highlight the current progress of therapeutic angiogenesis and the issues that need to be overcome prior to its clinical application.

Urinary neutrophil gelatinase-associated lipocalin (NGAL) can potentially predict vascular complications and reliably risk stratify patients with peripheral arterial disease

Neutrophil gelatinase-associated lipocalin (NGAL) is expressed in atherosclerotic plaques and implicated in the development of cardiovascular diseases. Peripheral arterial disease (PAD) is an atherosclerotic disease that often results in major cardiovascular events. This study aimed to prospectively examine the potential of urine NGAL (uNGAL) in predicting worsening PAD status and major adverse limb events (MALE). Baseline urine NGAL (uNGAL) and urine creatinine (uCr) concentrations were measured in PAD (n = 121) and non-PAD (n = 77) patients. Levels of uNGAL were normalized for urine creatinine (uNGAL/uCr). Outcomes included worsening PAD status, which was defined as a drop in ankle brachial index (ABI) > 0.15, and major adverse limb events (MALE), which was defined as a need for surgical revascularization or amputations. PAD patients had 2.30-fold higher levels of uNGAL/uCr [median (IQR) 31.8 (17.0–62.5) μg/g] in comparison to non-PAD patients [median (IQR) 73.3 (37.5–154.7) μg/g] (P = 0.011). Multivariate cox analysis showed that uNGAL/uCr levels were independently associated with predicting worsening PAD status and MALE outcomes. Cumulative survival analysis, over follow up period, demonstrated a direct correlation between elevated uNGAL/uCr levels and PAD disease progression and MALE outcomes. These data demonstrate an association between elevated uNGAL/uCr levels and worsening PAD disease status and MALE outcomes, indicating its potential for risk-stratification of PAD patients.

Diagnostic Accuracy of Ankle-Brachial Pressure Index Compared with Doppler Arterial Waveforms for Detecting Peripheral Arterial Disease: A Systematic Review

GENERAL PURPOSE

To present the results of a research study evaluating the diagnostic accuracy of the ankle-brachial pressure index (ABPI) compared with that of Doppler arterial waveforms (DAWs) to detect peripheral arterial disease (PAD).

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After completing this continuing education activity, the participant will:1. Summarize the evidence the authors considered when comparing the diagnostic accuracy of the ABPI with that of Doppler arterial waveforms to detect PAD.2. Select the characteristics of the participants in the studies the authors analyzed.3. Identify the results of the authors' study comparing the diagnostic accuracy of the ABPI with that of Doppler arterial waveforms to detect PAD.4. Distinguish the authors' conclusions about the advantages of using Doppler arterial waveforms to detect PAD.

Subunits of C1Q Are Associated With the Progression of Intermittent Claudication to Chronic Limb-Threatening Ischemia

Background

The pathophysiological mechanisms of intermittent claudication (IC) progression to chronic limb-threatening ischemia (CLTI) are still vague and which of patients with IC will become CLTI are unknown. This study aimed to investigate the key molecules and pathways mediating IC progression to CLTI by a quantitative bioinformatic analysis of a public RNA-sequencing database of patients with peripheral artery disease (PAD) to screen biomarkers discriminating IC and CLTI.

Methods

The GSE120642 dataset was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between IC and CLTI tissues were analyzed using the “edgeR” packages of R. The Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to explore the functions of DEGs. Protein–protein interaction (PPI) networks were established by the Search Tool for the Retrieval of Interacting Genes (STRING) database and visualized by Cytoscape software. Hub genes were selected by plugin cytoHubba. Gene set enrichment analysis was performed and the receiver operating characteristic curves were used to evaluate the predictive values of hub genes.

Results

A total of 137 upregulated and 21 downregulated DEGs were identified. Functional enrichment clustering analysis revealed a significant association between DEGs and the complement and coagulation cascade pathways. The PPI network was constructed with 155 nodes and 105 interactions. The most significantly enriched pathway was complement activation. C1QB, C1QA, C1QC, C4A, and C1R were identified and validated as hub genes due to the high degree of connectivity. The area under the curve values for the five hub genes were greater than 0.95, indicating high accuracy for discriminating IC and CLTI.

Conclusion

The complement activation pathway is associated with IC progression to CLTI. C1QB, C1QA, C1QC, C4A, and C1R might serve as potential early biomarkers of CLTI.