2016 AHA/ACC Guideline on the Management of Patients with Lower Extremity Peripheral Artery Disease: Executive Summary

Ankle Brachial Index in Different Types of Popliteal Artery Entrapment Syndrome: A Systematic Review of Case Reports

Similar to other peripheral artery diseases, vessel narrowing in popliteal artery entrapment syndrome (PAES) reduces the ankle brachial index (ABI). Since the PAES is related to several anatomical or functional variations, we sought to determine if the ABI was correlated with the type of syndrome. Through a systematic review of literature, we identified case reports and series in which the diagnosis of PAES was accompanied by ABI measurement. Twenty-seven studies included in the qualitative synthesis described 87 limbs. The most common types of the syndrome were those caused by an abnormal medial head of the gastrocnemius (type II, n = 35, 40.23%) and aberrant course of the popliteal artery (type I, n = 20, 22.99%). The variation of plantaris muscle (n = 7, 8.05%) is currently not included in the classification system. The median value of ABI was 0.87 (interquartile range (IQR) = 0.6-1.0). There were no differences among types of syndrome (F = 0.13, p = 0.72). In conclusion, despite clinical recommendations, the ABI remains underused in PAES diagnosis. No correlation was detected between the index score and type of syndrome. The cases of PAES involving structures other than the gastrocnemius or popliteus muscle suggest the need to revisit the current clinical classification system.

Perioperative Outcomes of Lower Extremity Revascularization for Rest Pain and Tissue Loss

BACKGROUND

Critical limb ischemia (CLI) is the clinical manifestation of severe peripheral artery disease presenting as rest pain (RP) and tissue loss (TL). Most studies compare CLI as a homogenous group with claudication with limited database studies specifically studying these differences. We hypothesize that CLI should be stratified into RP and TL because of significant differences in disease severity, comorbidities, and outcomes.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2016 was reviewed. All patients with a postoperative diagnosis of CLI undergoing femoral to popliteal bypass (FPB) with vein or graft were identified. Patients were stratified into cohorts based on International Classification of Disease (ICD)-9 or ICD-10 codes for RP or TL (gangrene or ulcer). Univariate and multivariate analyses were performed to examine 30-day mortality, morbidity, major amputation, and readmission adjusting for demographics, comorbidities, and procedural details.

RESULTS

There were 5,304 patients. Compared to RP, patients with TL were older (P < 0.0001) and more likely to be dependent (P < 0.0001). TL patients were also more likely to have diabetes (P < 0.0001), congestive heart failure (P < 0.0001), renal failure (P = 0.004), dialysis (P < 0.0001), history of wound infection (P < 0.0001), and sepsis (P < 0.0001). TL patients had higher American Society of Anesthesiologists class (P < 0.0001), were less likely to be transferred from home (P < 0.0001), and more likely to receive an FPB with vein (P = 0.03). Patients with TL had worse perioperative outcomes compared with RP in terms of pneumonia (P = 0.004), unplanned intubation (P = 0.009), cardiac arrest requiring cardiopulmonary resuscitation (P = 0.003), bleeding requiring transfusions (P < 0.0001), sepsis (P < 0.0001), septic shock (P = 0.02), and reoperation (P < 0.0001). TL was associated with significantly higher 30-day morbidity (P < 0.0001), 30-day mortality (P < 0.0001), major amputation (P = 0.0004), and readmission rates (P = 0.005). Patients with TL compared with those with RP also had longer hospital stays (P < 0.0001) and days between operation to discharge (P < 0.0001). TL was independently associated with increased 30-day morbidity (OR: 1.16 [1.00-1.35]) and major amputation (OR: 2.48 [1.29-4.76]) compared with RP.

CONCLUSIONS

Patients with RP and TL have drastic differences that impact perioperative mortality and readmissions. TL is an independent predictor of 30-day morbidity and major amputation. The stratification of CLI into RP and TL can provide insight into variations in outcomes and provide a means to quantify the risks associated with the 2 manifestations of the disease.

Peripheral Vascular Disease in Women: Therapeutic Options in 2019

PURPOSE OF REVIEW

In recent years, there have been advances in the prevention, management, and control of peripheral vascular disease (PVD). There is a trend towards aggressive risk factor modification, noninvasive screening, and endovascular revascularization with surgical approaches reserved only for select cases. This article reviews the different management strategies ranging from pharmacotherapy, revascularization, and rehabilitation with an emphasis on the response of women to these therapies.

RECENT FINDINGS

Overall, the representation of women in the majority of the published data in this arena remains poor. Studies examining medical therapy and endovascular and surgical revascularization were not designed to address sex disparities. Nevertheless, we dissect these therapies and their relevant randomized trials. The paucity of data investigating the response of women to the different management options makes it difficult to make any evidence-based recommendations. This not only applies to the type of intervention, but also the appropriate timing and risks entailed.

Provisional Stenting Using the Zilver PTX Drug-Eluting Stent After Drug-Coated Balloon Angioplasty: Initial Experience From the Double Drug Dose "3D" Study

Purpose: To explore the provisional use of a drug-eluting stent (DES) after suboptimal drug-coated balloon (DCB) angioplasty in complex, calcified femoropopliteal lesions. Materials and Methods: A prospective, single-center, investigator-initiated pilot study enrolled 15 patients (mean age 71.3 years; 9 men) with symptomatic stenosis (n=6) or occlusion (n=9) of the native superficial femoral and/or proximal popliteal arteries who experienced suboptimal DCB dilation despite postdilation. Lesion characteristics were evaluated with computed tomography angiography and duplex ultrasound confirmed by intravascular ultrasound. Follow-up included clinical and imaging evaluations as well as blood tests to monitor inflammatory markers. Endpoints included systemic inflammation, acute/chronic thrombosis, aneurysm formation, and mortality. Results: Provisional stenting was required for residual stenosis >50% in 4 cases and flow-limiting dissection in 11. Provisional spot stenting was done using the Zilver PTX DES. Clinical improvement was observed in all cases. After 24-month follow-up all patients were alive and in good clinical condition. One- and 2-year primary patency rates were 93.3% and 92.9%, respectively; secondary patency was 100%. Restenosis required reintervention in 2 cases. No local or systemic complications or toxicity were observed due to the use of a double dose of paclitaxel. No significant increase in any inflammation marker was observed in the perioperative period, and no aneurysm formation was seen over 24 months of follow-up. Conclusion: Combined DCB plus DES therapy seems to be safe and correlated with high primary patency following suboptimal angioplasty. Larger studies are required to confirm the safety and efficacy of this approach.

Medical adjunctive therapy for patients with chronic limb-threatening ischemia: a systematic review

INTRODUCTION

The aim of this article is to systematically review the literature on medical adjunctive therapy for patients with chronic limb-threatening ischemia (CLTI).

EVIDENCE ACQUISITION

MEDLINE, Embase, and Cochrane Database of Systematic Reviews were searched for studies published between January 1st, 2009, and June 1st, 2019. Articles that studied medical treatment of CLTI patients and reported clinical outcomes were eligible. Main exclusion criteria were case reports <20 patients, incorrect publication type, and CLTI caused by Buerger disease. The primary end point was major amputation (above the ankle) in studies with a follow-up of ≥6 months. Secondary end points were other clinical end points such as death and wound healing. Study quality was assessed according to the Downs and Black checklist.

EVIDENCE SYNTHESIS

Included were 42 articles: four focused on antiplatelet therapy, five on antihypertensive medication, 6 on lipid-lowering therapy, 16 on stem cell therapy, three on growth factors, five on prostanoids, and one study each on cilostazol, glucose-lowering therapy, spinal cord stimulation, sulodexide, and hemodilution. Calcium channel blockers, iloprost, cilostazol, and hemodilution showed significant improvement of limb salvage, but data are limited. Stem cell therapy showed no significant improvement of limb salvage but could potentially improve wound healing. Antiplatelets, antihypertensives, and statins showed significantly lower cardiovascular events rates but not evident lower major amputation rates. The quality of the studies was fair to good.

CONCLUSIONS

Certain medical therapies serve to improve limb salvage next to revascularization in CLTI patients, whereas others are important in secondary prevention. Because high quality evidence is limited, further research is needed.

Role of Nitric Oxide Carried by Hemoglobin in Cardiovascular Physiology: Developments on a Three-Gas Respiratory Cycle

A continuous supply of oxygen is essential for the survival of multicellular organisms. The understanding of how this supply is regulated in the microvasculature has evolved from viewing erythrocytes (red blood cells [RBCs]) as passive carriers of oxygen to recognizing the complex interplay between Hb (hemoglobin) and oxygen, carbon dioxide, and nitric oxide-the three-gas respiratory cycle-that insures adequate oxygen and nutrient delivery to meet local metabolic demand. In this context, it is blood flow and not blood oxygen content that is the main driver of tissue oxygenation by RBCs. Herein, we review the lines of experimentation that led to this understanding of RBC function; from the foundational understanding of allosteric regulation of oxygen binding in Hb in the stereochemical model of Perutz, to blood flow autoregulation (hypoxic vasodilation governing oxygen delivery) observed by Guyton, to current understanding that centers on S-nitrosylation of Hb (ie, S-nitrosohemoglobin; SNO-Hb) as a purveyor of oxygen-dependent vasodilatory activity. Notably, hypoxic vasodilation is recapitulated by native S-nitrosothiol (SNO)-replete RBCs and by SNO-Hb itself, whereby SNO is released from Hb and RBCs during deoxygenation, in proportion to the degree of Hb deoxygenation, to regulate vessels directly. In addition, we discuss how dysregulation of this system through genetic mutation in Hb or through disease is a common factor in oxygenation pathologies resulting from microcirculatory impairment, including sickle cell disease, ischemic heart disease, and heart failure. We then conclude by identifying potential therapeutic interventions to correct deficits in RBC-mediated vasodilation to improve oxygen delivery-steps toward effective microvasculature-targeted therapies. To the extent that diseases of the heart, lungs, and blood are associated with impaired tissue oxygenation, the development of new therapies based on the three-gas respiratory system have the potential to improve the well-being of millions of patients.

Development of drug-coated balloon for the treatment of multiple peripheral artery segments

OBJECTIVE

Peripheral artery disease is the second most common cardiovascular disease. It can often occur in complex form when there is a presence of long, diffuse, and multiple lesions. Current treatments use either single long drug-coated balloons (DCBs) or multiple DCBs; however, treatment success is limited. The purpose of this study was to investigate the preclinical feasibility of our multiple-release Tailored Medical Devices DCB (MR-TMD-DCB) to treat multiple arterial segments using a single DCB.

METHODS

The MR-TMD-DCBs were developed using a two-layer coating approach. The DCBs were developed in a certified Current Good Manufacturing Practices facility using presterilized materials and reagent and then characterized for coating morphology, thermal and chemical changes, and in vitro particulate shedding. The drug loss, tissue uptake, and undelivered drug amounts were analyzed using an in vitro peripheral artery flow model and explanted pig arteries. Then, an in vivo survival study was performed using a healthy porcine model to measure the short-term drug uptake (seven swine; 14 treatments at day 1) and retention (seven swine; 14 treatments at day 7) in two different arterial segments after treatment with a single MR-TMD-DCB.

RESULTS

The coating on the MR-TMD-DCB was smooth and homogeneous with paclitaxel molecularly dispersed in its amorphous state. A negligible number of particulates were shed from the MR-TMD-DCB coating. A similar amount of drug was accurately delivered into two separate explanted arteries using a single MR-TMD-DCB during the in vitro flow model testing (707 ± 109 ng/mg in the first explanted artery and 783 ± 306 ng/mg in the second explanted artery). The MR-TMD-DCB treatment resulted in equivalent drug amounts in the two arterial segments at day 1 (63 ± 19 ng/mg in the first treatment site and 59 ±19 ng/mg in the second treatment site) and at day 7 (9 ± 6 ng/mg in the first treatment site and 10 ± 6 ng/mg in the second treatment site). In addition, the drug levels at each time point were in the clinically relevant range to prevent neointimal hyperplasia.

CONCLUSIONS

The MR-TMD-DCBs provided equivalent and clinically relevant drug retention levels into two different arterial segments. Thus, MR-TMD-DCBs can be used to accurately deliver drug into multiple arterial segments with the use of a single DCB. The clinical outcomes of these findings need further investigation. Future long-term pharmacokinetics and safety studies will be performed to evaluate the safety and efficacy of the MR-TMD-DCB.

Restless Leg Syndrome in Peripheral Artery Disease: Prevalence among Patients with Claudication and Benefits from Low-Intensity Exercise

Restless leg syndrome (RLS) disrupts sleep, affecting the quality of life of patients with various chronic diseases. We assessed the prevalence of RLS in peripheral artery disease (PAD) patients and the effects of a pain-free exercise program. A total of 286 patients with claudication were enrolled in a home-based low-intensity exercise program prescribed at the hospital. RLS was determined through standardized questions. Hemodynamics, degree of calf deoxygenation, and mobility were assessed using the ankle-brachial-index, a treadmill test assisted by near-infrared spectroscopy and the 6-min walk test, respectively. During hospital visits, persistence of RLS, adherence to exercise, hemodynamics, and mobility were assessed. At the enrollment, 101 patients (35%) presented RLS, with higher prevalence among females (p = 0.032). Compared to RLS-free patients, they showed similar hemodynamics but more severe calf deoxygenation (p < 0.001) and lower mobility (p = 0.040). Eighty-seven RLS patients (83%) reported the disappearance of symptoms after 39 (36−70) days of exercise. This subgroup, compared to nonresponders, showed higher adherence (p < 0.001), hemodynamic (p = 0.041), and mobility improvements (p = 0.003). RLS symptoms were frequent in PAD but were reduced by a pain-free walking exercise aimed at inducing peripheral aerobic adaptations. The concomitant recovery of sleep and mobility may represent a synergistic action against the cardiovascular risk in PAD.

Ankle-brachial index and incident heart failure with reduced versus preserved ejection fraction: The Multi-Ethnic Study of Atherosclerosis

This study investigated the relationship between ankle-brachial index (ABI) and risk for heart failure with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). ABI has previously been associated with mortality, cardiovascular disease (CVD), and overall HF but the relationship between ABI and risk of HF stratified by EF has not been well characterized. We analyzed data from 6553 participants (53% female; mean age 62 ± 10 years) enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA) who were free of known clinical CVD/HF at baseline (2000-2002) and had baseline ABI measured. Participants were classified as low (≤ 0.90), borderline-low (0.91-1.00), normal (1.01-1.40), and high (> 1.40) ABI. Incident hospitalized HF was determined over a median follow-up of 14 years; we classified HF events (n = 321) as HFrEF with EF < 50% (n = 155, 54%) or HFpEF with EF ⩾ 50% (n = 133, 46%). Low ABI was associated with incident HFrEF (hazard ratio (HR): 2.02, 95% CI 1.19-3.40, p = 0.01) and had no significant association with HFpEF (HR: 0.67, 95% CI 0.30-1.48, p = 0.32). Borderline-low and high ABI were not significantly associated with HFrEF or HFpEF. Cubic spline analyses showed association with both low and high ABI for HFrEF and high ABI for HFpEF. A 1 SD lower ABI (for ABI < 1.1) was associated with incident HFrEF in multivariable analysis (HR: 1.27, 95% CI 1.05-1.54) but was not significant after additionally adjusting for interim myocardial infarction (HR: 1.21, 95% CI 0.99-1.48). Low ABI was associated with higher risk for incident HFrEF but not HFpEF in persons free of known CVD. Future studies of a larger size are needed for high ABI analyses.

Delayed gratification and adherence to exercise among patients with claudication

Few studies have explicitly identified factors that explain an individual's willingness to engage in community-based exercise for claudication. Identifying the unique characteristics of those inclined toward physical activity would inform interventions that encourage walking. We examined the utility of behavioral economics-related concepts in understanding walking among Veterans with claudication. Patients who received care at the Michael E. DeBakey Veterans Affairs Medical Center in Houston, Texas, were surveyed on symptom severity, behavioral economics, stress, and depression. The primary outcome was a binary variable measuring current walking for exercise and defined as walking for at least 30 minutes every day. Multivariable logistic regression models were used to identify variables, both clinically and statistically significant, at a p-value < 0.05. Between April 2017 and March 2018, we received 148 (30%) responses. A total of 35% (n = 51) of respondents indicated that they walked recreationally for exercise compared to 65% (n = 94) who did not. Characteristics that were significantly associated with walking included regularly saving money (adjusted odds ratio (aOR) = 10.7, p = 0.001), seeking complex problem-solving (aOR = 0.12, p = 0.002), and severe symptoms (aOR = 0.24, p = 0.017). Individuals describing a preference for the future rather than immediate benefit also reported currently walking for exercise. Defining the characteristics of those who exercise may help inform strategies designed to increase walking among those who do not adhere to recommendations.

Heterogeneity in Standard Operating Procedures for Catheter Directed Thrombolysis for Peripheral Arterial Occlusions in The Netherlands: A Nationwide Overview

OBJECTIVE

Catheter directed thrombolysis (CDT) for acute arterial occlusions of the lower extremities is associated with a risk of major bleeding complications. Strict monitoring of vital functions is advised for timely adjustment or discontinuation of thrombolytic treatment. Nevertheless, current evidence on the optimal application of CDT and use of monitoring during CDT is limited. In this study the different standard operating procedures (SOPs) for CDT in Dutch hospitals were compared against a national guideline in a nationwide analysis.

METHODS

SOPs, landmark studies, and national and international guidelines for CDT for acute lower extremity arterial occlusions were compared. The protocols of 34 Dutch medical centres where CDT is performed were assessed. Parameters included contraindications to CDT, co-administration of heparin, thrombolytic agent administration, angiographic control, and patient monitoring.

RESULTS

Thirty-four SOPs were included, covering 94% of medical centres performing CDT in the Netherlands. None of the SOPs had identical contraindications and a strong divergence in relative and absolute grading was found. Heparin and urokinase dosages differed by a factor of five. In 18% of the SOPs heparin co-administration was not mentioned. Angiographic control varied between once every 6 h to once every 24 h. In 76% of the SOPs plasma fibrinogen levels were used for CDT dose adjustments. However, plasma fibrinogen level threshold values for treatment adjustments varied between 2.0 g/L and 0.5 g/L.

CONCLUSION

The SOPs for CDT for acute arterial occlusions of the lower extremities differ greatly on five major operating aspects among medical centres in the Netherlands. None of the SOPs exactly conforms to current national or international guidelines. This study provides direction on how to increase homogeneity in guideline recommendations and to improve guideline adherence in CDT.

Real-world outcomes of endovascular treatment in a non-selected population with peripheral artery disease - prospective study with 2-year follow-up

Background: The study aimed to evaluate the outcomes of percutaneous transluminal angioplasty (PTA) in lower-extremity peripheral artery disease (PAD) patients. Patients and methods: A multi-centre, observational study was performed with 32 German and Austrian centres contributing data to the PTA registry. Data of 1,781 patients with lower-leg and pelvic PAD who were suitable for endovascular PTA treatment were contributed from participating centres. Data from 1,533 patients are reported here (1,055 male and 478 female). This study did not have exclusion criteria. Quality of life (QOL) questionnaire (EQ-5D) scores, Rutherford classification, mortality, patency rate and details of major adverse cardiovascular events were collected at 6-, 12-, 18-, and 24-month follow ups. Results: PTA with/without stenting achieved 90.3 %, 86.5 %, 82.7 %, and 71.9 % technical success (recanalisation achieving ≥ 70 % patency, no evidence of embolisation, recoiling or dissection) in iliac, femoral, popliteal, and below-the-knee arteries, respectively. Procedural/postprocedural complications occurred in 142 (9.3 %, 1 death) and 74 (4.8 %) patients. QOL, mobility, self-care, activity, and pain/discomfort scores improved (p < 0.01), anxiety/depression was insignificantly improved. During follow-up, 409 (26.7 %) patients were hospitalised for PAD, 281 (18.3 %) required reintervention, and 145 (9.5 %) died or needed amputation (n = 49; 3.2 %). Multivariate analysis demonstrated poorer outcomes in patients with comorbidities. Conclusions: PTA with/without stenting is effective, safe, and widely applicable, with few complications. It improves QOL, but not anxiety/depression.

Oscillometric and Doppler Ankle Brachial Indexes as predictors of all-cause mortality in a Primary Care population

BACKGROUND

Doppler Ankle Brachial Index (ABI), the non-invasive reference standard for peripheral arterial disease (PAD) in Primary Care, has proved good capacity to predict all-cause mortality. However, the role of oscillometric ABI is uncertain. This study aims to evaluate the ability of oscillometric and Doppler ABI to predict all-cause mortality in a Primary Care population.

METHODS

Oscillometric and Doppler ABI were measured in 203 consecutive subjects with ≥1 cardiovascular risk factors or intermittent claudication. Pathologic ABI was defined when ABI was ≤0.9 or ≥1.4, and when the oscillometer was unable to record a value (oscillometric error). All-cause mortality was ascertained through examination of electronic medical records or telephone contact.

RESULTS

After analyzing 602.9 subjects/year, all-cause mortality was recorded in 17 (8.4%) patients. Kaplan-Meier survival curves for oscillometric (Log-Rank test χ2=66.02, P<0.001) and Doppler ABI (Log-Rank test χ2=42.30, P<0.001) showed that a pathologic ABI is associated with all-cause mortality. After adjusting for covariates, the hazard ratio in multivariable Cox regression were 4.52 (95% CI: 1.67-12.18, P=0.003) and 2.08 (95% CI: 0.83-5.18, P=0.117) for oscillometric and Doppler ABI models, respectively. When introducing oscillometric and Doppler ABI simultaneously in the Cox regression model, only oscillometric ABI was an independent predictor with a hazard ratio=7.90 (95% CI: 1.79-34.83, P=0.006). Regarding Doppler ABI, no significant differences were found in all-cause mortality between low ABI (≤0.9) and calcified ABI (≥1.4), (Log-Rank test χ2=0.98, P=0.322).

CONCLUSIONS

Oscillometric ABI predicted all-cause mortality in a Primary Care population even better than Doppler ABI, irrespective of cardiovascular risk factors. Oscillometric ABI, due to a high feasibility, could routinely identify high-risk patients to implement preventive measures.

Test-retest reliability, agreement, and minimal detectable change in the 6-minute walk test in patients with intermittent claudication

OBJECTIVE

Standardized walk tests are important for objective assessment of walking distance in patients with intermittent claudication (IC). The 6-minute walk test (6MWT) has been suggested to correlate more closely than testing on a treadmill with everyday ambulatory function, but its measurement properties have hardly been studied in IC. The aim of this study was to determine the test-retest reliability, agreement, standard error of measurement (SEM), and minimal detectable change of the 6MWT in patients with IC.

METHODS

This reliability and agreement study recruited 102 patients with stable IC (mean age, 72 ± 7.4 years; 43 women) from the vascular surgery outpatient clinic at Sahlgrenska University Hospital in Sweden. The patients performed the 6MWT twice, with at least 30 minutes of rest between tests. To determine test-retest reliability, the intraclass correlation coefficient was calculated. Bland-Altman plots were used to measure agreement.

RESULTS

The mean walking distance in both test and retest was 397.8 m (standard deviation, 81.2 m; N = 100), and the individual walking distance varied from 175 to 600 m. Excellent test-retest reliability for the 6MWT (intraclass correlation coefficient, 0.95; 95% confidence interval, 0.9-0.97) was observed. The SEM was 16.6 m (95% confidence interval, 14.6-19.3), the SEM percentage was 4.2%, and the minimal detectable change was 46 m. Five observations (5%) were positioned outside the limits of agreement; there was a small proportional bias, and the scatter of values for differences decreased as the average values increased.

CONCLUSIONS

The excellent test-retest reliability implies that it is sufficient for a patient with IC to perform the 6MWT once, at every test occasion. For the individual, an improvement or deterioration in maximum walking distance of >46 m after an intervention would be required to be 95% confident that the change is significant. Being a simple and clinically useful test, the 6MWT can be widely used to evaluate the effects of different interventions in patients with IC.

Outcomes with cilostazol after endovascular therapy of peripheral artery disease

The role of cilostazol after endovascular therapy (EVT) of peripheral artery disease (PAD) remains unclear. We conducted a meta-analysis for all studies reporting the outcomes of cilostazol after EVT of PAD from January 2000 through November 2018 with the outcomes of interest including primary patency, major adverse limb events (MALE), target lesion revascularization (TLR), and major amputation. We included eight studies (three randomized controlled trials (RCTs) and five observational studies) with a total of 3846 patients (4713 lesions). During a mean follow-up duration of 12.5 ± 5 months, the use of cilostazol was associated with higher primary patency (OR 2.28, 95% CI (1.77, 2.94), p < 0.001, I² = 24%), lower risk of TLR (OR 0.37, 95% CI (0.26, 0.52), p < 0.001, I² = 0%), and lower risk of major amputation (OR 0.15, 95% CI (0.04, 0.62), p = 0.008, I² = 0%). The use of cilostazol in RCTs was associated with significantly higher odds of primary patency compared with observational studies (OR 3.37 vs 2.28, p-interaction = 0.03). After further subgroup analysis, cilostazol remained associated with higher primary patency regardless of the use of anticoagulants (warfarin) (p-interaction = 0.49). We conclude that the use of cilostazol after EVT of femoropopliteal and iliac lesions is associated with improved primary patency and lower risk of major amputation and TLR. The favorable impact of cilostazol is independent of the use of warfarin. PROSPERO identifier: CRD42018092715.

Anticoagulation in addition to dual antiplatelet therapy has no impact on long-term follow-up after endovascular treatment of (sub)acute lower limb ischemia

Background: To assess the impact of short- vs. long-term anticoagulation in addition to standard dual antiplatelet therapy (DAPT) upon endovascular treatment of (sub)acute thrombembolic occlusions of the lower extremity. Patient and methods: Retrospective analysis was conducted on 202 patients with a thrombembolic occlusion of lower extremities, followed by crirical limb ischemia that received endovascular treatment including thrombolysis, mechanical thrombectomy, or a combination of both between 2006 and 2015 at a single center. Following antithrombotic regimes were compared: 1) dual antiplatelet therapy, DAPT for 4 weeks (aspirin 100 mg/d and clopidogrel 75 mg/d) upon intervention, followed by a lifelong single antiplatelet therapy; 2) DAPT plus short term anticoagulation for 4 weeks, followed by a lifelong single antiplatelet therapy; 3) DAPT plus long term anticoagulation for > 4 weeks, followed by a lifelong anticoagulation. Results: Endovascular treatment was associated with high immediate revascularization (> 98 %), as well as overall and amputation-free survival rates (> 85 %), independent from the chosen anticoagulation regime in a two-year follow up, p > 0.05. Anticoagulation in addition to standard antiplatelet therapy had no significant effect on patency or freedom from target lesion revascularization (TLR) 24 months upon index procedure for both thrombotic and embolic occlusions. Severe bleeding complications occurred more often in the long-term anticoagulation group (9.3 % vs. 5.6 % (short-term group) and 6.5 % (DAPT group), p > 0.05). Conclusions: Our observational study demonstrates that the choice of an antithrombotic regime had no impact on the long-term follow-up after endovascular treatment of acute thrombembolic limb ischemia whereas prolonged anticoagulation was associated with a nominal increase in severe bleeding complications.

Moderate-pain versus pain-free exercise, walking capacity, and cardiovascular health in patients with peripheral artery disease

OBJECTIVE

Supervised exercise training (walking) is recommended in patients with intermittent claudication, both as a means to improve symptoms (walking distance and quality of life [QoL]) and as a means to improve general cardiovascular health (including vascular function and heart rate variability [HRV]). Our aim was to compare two types of supervised training (moderate-pain and pain-free walking) with comparable intensity based on heart rate, in terms of walking capacity, QoL, vascular function, biomarkers, and HRV in patients with intermittent claudication.

METHODS

Thirty-six adults with intermittent claudication were randomized to either moderate-pain or pain-free exercise training (36 sessions, two or three times a week) or usual care (no supervised exercise). Initial walking distance and absolute walking distance using treadmill testing, flow-mediated vasodilation and pulse wave velocity using ultrasound, N-terminal pro-B-type natriuretic peptide and fibrinogen levels, HRV, and QoL (36-Item Short Form Health Survey questionnaire) were determined at baseline and after the intervention period.

RESULTS

Twenty-nine patients (mean age, 64 ± 9 years; 72% male) completed the study. Both training programs similarly improved walking capacity. Initial walking distance and absolute walking distance significantly increased with either moderate-pain walking (median, 50 m to 107 m [P = .005] and 85 m to 194 m [P = .005], respectively) or pain-free walking (median, 53 m to 128 m [P = .003] and 92 m to 163 m [P = .003], respectively). QoL also similarly improved with both training modalities, whereas only moderate-pain walking was also associated with a statistically significant improvement in the vascular parameters flow-mediated vasodilation (4.4% to 8.0%; P = .002) and pulse wave velocity (6.6 m/s to 6.1 m/s; P = .013). Neither training program was associated with changes in biomarker levels and HRV.

CONCLUSIONS

Both moderate-pain and pain-free training modalities were safe and similarly improved walking capacity and health-related QoL. Conversely, vascular function improvements were associated with only moderate-pain walking.

Rehabilitative Exercise Reduced the Impact of Peripheral Artery Disease on Vascular Outcomes in Elderly Patients with Claudication: A Three-Year Single Center Retrospective Study

The study retrospectively evaluated the association between rehabilitative outcomes and risk of peripheral revascularizations in elderly peripheral artery disease (PAD) patients with claudication. Eight-hundred thirty-five patients were enrolled. Ankle-brachial index (ABI) and maximal walking speed (S_max) were measured at baseline and at discharge from a structured home-based rehabilitation program. For the analysis, patients were divided according to a baseline ABI value (severe: ≤0.5; moderate: ≥0.5) and according to hemodynamic or functional rehabilitative response (responder: ABI ≥ 0.10 and/or S_max > 0.5 km/h). Three-year outcomes were collected from the regional registry. According to the inclusion criteria (age 60–80, ABI < 0.80; program completion) 457 patients, 146 severe and 311 moderate, were studied. The whole population showed significant functional and hemodynamic improvements at discharge, with 56 revascularizations and 69 deaths at follow-up. Compared to the moderate group, the severe group showed a higher rate of revascularizations (17% vs. 10%, p < 0.001) and deaths (29% and 8%, respectively; p < 0.001). However, patients with severe PAD who were ABI responders after rehabilitation showed less revascularizations than non-responders (13% vs. 21%; hazard ratio (HR): 0.52) and were not different from patients with moderate disease (9%). Superimposable rates were observed for S_max responders (13% vs. 21%; HR: 0.55; moderate 10%). In conclusion, elderly patients with severe PAD empowered by better rehabilitation outcomes showed lower rates of peripheral revascularizations and deaths that were comparable to patients with moderate PAD.

Peripheral artery disease risk factors in Jeddah, Saudi Arabia: a retrospective study

Background

Peripheral artery disease (PAD) is a major health problem in Saudi Arabia with considerable implications for morbidity and mortality. Many risk factors have been established for developing PAD, but the prevalence of these risk factors is variable from one country to another.

Aim

To identify the risk factors for PAD and study their prevalence in Jeddah, Saudi Arabia.

Methods

A retrospective chart review study was conducted in a tertiary center in Jeddah from July 2012 to September 2015. All patients with PAD were recruited into this study, and their data were analyzed using IBM SPSS. Correlation between PAD and various risk factors was studied using Spearman's coefficient.

Results

A total of 261 patients were recruited, of which 55% were males. Hypertension, diabetes type 2, and obesity were found among 34.2%, 33.3%, and 29.2% of the patients, respectively. About 45% had a history of previous vascular surgery, and amputation was performed in 6.9% particularly in legs. Hypertension and metabolic syndrome were the only risk factors that showed a significant correlation with PAD (P=0.039 and 0.040, respectively).

Conclusion

The most prevalent risk factors for PAD in Jeddah were hypertension, diabetes, obesity, and smoking. Hypertension and metabolic syndrome were the only risk factors significantly associated with PAD. Males were often more affected by PAD than females. The most commonly affected site was the lower limbs.

Urgent need to clarify the definition of chronic critical limb ischemia - a position paper from the European Society for Vascular Medicine

Chronic critical lower limb ischemia (CLI) has been defined as ischemia that endangers the leg. An attempt was made to give a precise definition of CLI, based on clinical and hemodynamic data (Second European Consensus). CLI may be easily defined from a clinical point of view as rest pain of the distal foot or gangrene or ulceration. It is probably useful to add leg ulcers of other origin which do not heal because of severe ischemia, and to consider the impact of frailty on adverse outcome. From a hemodynamic viewpoint there is no consensus and most of the existing classifications are not based upon evidence. We should thus propose a definition and then validate it in a prospective cohort in order to define the patients at major risk of amputation, and also to define the categories of patients whose prognosis is improved by revascularisation. From today's available data, it seems clear that the patients with a systolic toe pressure (STP) below 30 mmHg must be revascularised whenever possible. However other patients with clinically suspected CLI and STP above 30 mmHg must be evaluated and treated in specialised vascular units and revascularisation has to be discussed on a case by case basis, taking into account other data such as the WiFi classification for ulcers.In conclusion, many useful but at times contradictory definitions of CLI have been suggested. Only a few have taken into account evidence, and none have been validated prospectively. This paper aims to address this and to give notice that a CLI registry within Europe will be set up to prospectively validate, or not, the previous and suggested definitions of CLI.

Near infrared spectroscopy-guided exercise training for claudication in peripheral arterial disease

Rationale

Supervised treadmill exercise for claudication in peripheral arterial disease is effective but poorly tolerated because of ischemic leg pain. Near infrared spectroscopy allows non-invasive detection of muscle ischemia during exercise, allowing for characterization of tissue perfusion and oxygen utilization during training.

Objective

We evaluated walking time, muscle blood flow, and muscle mitochondrial capacity in patients with peripheral artery disease after a traditional pain-based walking program and after a muscle oxygen-guided walking program.

Method and results

Patients with peripheral artery disease trained thrice weekly in 40-minute-long sessions for 12 weeks, randomized to oxygen-guided training ( n = 8, age 72 ± 9.7 years, 25% female) versus traditional pain-based training ( n = 10, age 71.6 ± 8.8 years, 20% female). Oxygen-guided training intensity was determined by maintaining a 15% reduction in skeletal muscle oxygenation by near infrared spectroscopy rather than relying on symptoms of pain to determine exercise effort. Pain free and maximal walking times were measured with a 12-minute Gardner treadmill test. Gastrocnemius mitochondrial capacity and blood flow were measured using near infrared spectroscopy. Baseline pain-free walking time was similar on a Gardner treadmill test (2.5 ± 0.9 vs. 3.6 ± 1.0 min, p = 0.5). After training, oxygen-guided cohorts improved similar to pain-guided cohorts (pain-free walking time 6.7 ± 0.9 vs. 6.9 ± 1.1 min, p < 0.01 for change from baseline and p = 0.97 between cohorts). Mitochondrial capacity improved in both groups but more so in the pain-guided cohort than in the oxygen-guided cohort (38.8 ± 8.3 vs. 14.0 ± 9.3, p = 0.018). Resting muscle blood flow did not improve significantly in either group with training.

Conclusions

Oxygen-guided exercise training improves claudication comparable to pain-based training regimens. Adaptations in mitochondrial function rather than increases in limb perfusion may account for functional improvement. Increases in mitochondrial oxidative capacity may be proportional to the degree of tissue hypoxia during exercise.

A novel computer-aided diagnostic approach for detecting peripheral arterial disease in patients with diabetes

Peripheral arterial disease (PAD) is an important manifestation of systemic atherosclerosis, with diabetes being one of its most significant risk factors. Owing to medial arterial calcification (MAC), the ankle–brachial index (ABI) is not always a reliable tool for detecting PAD. Arterial Doppler flow parameters, such as systolic maximal acceleration (ACCmax) and relative pulse slope index (RPSI), may serve as effective surrogates to detect stenosis-induced flow alteration. In the present study, ACCmax and RPSI were prospectively evaluated in 166 patients (304 arteries) with clinical suspicion of PAD, including 76 patients with and 90 patients without diabetes. In the overall sample, the sensitivity of ACCmax (69%) was superior to that of ABI (58%) and RPSI (56%). In patients with diabetes, the sensitivity of ACCmax (57%), ABI (56%) and RPSI (57%) were similar, though a parallel test taking both ACCmax and RPSI into account further increased sensitivity to 68%. The specificity (98%) and accuracy (78%) of ACCmax were superior to those of ABI (83% and 70%, respectively), as were the specificity (95%) and accuracy (77%) of RPSI in patients with diabetes. The diagnostic properties of ACCmax and RPSI were superior to those of ABI for detecting PAD in patients with diabetes. Our acceleration algorithm (Gefäßtachometer^®) provides a rapid, safe, noninvasive tool for identifying PAD in patients with diabetes.

Drug-Eluting Stents for Treatment of Peripheral Artery Disease

Endovascular intervention is a mainstay treatment of peripheral artery disease (PAD) in addition to aggressive risk factor modification and exercise programs in patients with favorable anatomy or in those who are considered too high risk for surgical intervention. Treatment with percutaneous transluminal angioplasty (PTA) and bare metal stents (BMS) has been limited by high rates of in-stent restenosis (ISR) requiring repeat revascularization. Drug-eluting stents (DES), developed and designed to reduce ISR, offer a promising solution to the current challenges in endovascular management of PAD. Several randomized clinical trials have shown improved short- and mid-term outcomes with DES as compared with both PTA and BMS. Herein we provide an up-to-date review of the current literature on DES use in PAD.

Minimal clinically important differences in treadmill, 6-minute walk, and patient-based outcomes following supervised and home-based exercise in peripheral artery disease

We estimated minimal clinically important differences (MCIDs) for small, moderate, and large changes in measures obtained from a standardized treadmill test, a 6-minute walk test, and patient-based outcomes following supervised and home-based exercise programs in symptomatic patients with peripheral artery disease (PAD). Patients were randomized to either 12 weeks of a supervised exercise program ( n=60), a home-based exercise program ( n=60), or an attention-control group ( n=60). Using the distribution-based method to determine MCIDs, the MCIDs for small, moderate, and large changes in peak walking time (PWT) in the supervised exercise group were 38, 95, and 152 seconds, respectively, and the changes in claudication onset time (COT) were 35, 87, and 138 seconds. Similar MCID scores were noted for the home-based exercise group. An anchor-based method to determine MCIDs yielded similar patterns of small, moderate, and large change scores in PWT and COT, but values were 1-2 minutes longer than the distribution approach. In conclusion, 3 months of supervised and home-based exercise programs for symptomatic patients with PAD results in distribution-based MCID small, moderate, and large changes ranging from 0.5 and 2.5 minutes for PWT and COT. An anchor-based approach yields higher MCID values, ranging from a minimum of 73 seconds for COT to a maximum of 4 minutes for PWT. The clinical implication is that a goal for eliciting MCIDs in symptomatic PAD patients through a walking exercise intervention is to increase PWT and COT by up to 4 minutes, which corresponds to two work stages during the standardized progressive treadmill test.

Below-the-Knee Retrograde Access for Peripheral Interventions: A Systematic Review

PURPOSE

To investigate the hypothesis that interventions involving retrograde below-the-knee (BTK) vessel punctures have an acceptably low complication rate and high procedural success.

METHODS

A systematic review was performed of the MEDLINE and Scopus databases for articles describing the results of BTK retrograde access for peripheral interventions. Outcome measures were access success, procedure success, and complications. A predefined subgroup analysis was performed of prospective studies to reduce the influence of possible reporting bias on outcomes.

RESULTS

Nineteen articles, including 3 prospective studies, were selected, including a total of 1905 interventions in 1395 patients (mean age 69.5 years; 918 men). The BTK vessels were punctured in 1168 (61.3%) of these interventions. Access was successful in 94.0% of BTK attempts, 86.0% of all lesions were successfully crossed using a retrograde access, and 84.0% of interventions achieved technical success. Forty-eight (4.1%) distal access site complications were reported. Vessel perforations were seen in 13 (1.1%) interventions, vasospasm in 5 (0.4%), and acute distal occlusions in 5 (0.4%). Predefined subgroup analysis of prospective studies showed similar results (p=0.24).

CONCLUSION

A retrograde approach to facilitate peripheral endovascular interventions is a safe and successful technique and should be considered when an antegrade approach is not possible or fails to cross the lesion. Because of missing data on long-term outcomes and methodological shortcomings, real world data of retrograde access in nonexpert centers remains necessary before this technique can be advised to all interventionists dealing with peripheral artery disease.