2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Impaired heart rate variability, Valsalva and 30:15 ratio indexes are associated with reduced submaximal exercise capacity in subjects with diabetes mellitus

AIMS

To assess cardiac autonomic control and its association with submaximal exercise measured using the 6-minute walk test (6MWT) in subjects with type-2 diabetes mellitus (DM2).

METHODS

Cardiac autonomic control was assessed using Ewing's tests and heart rate variability (HRV) in DM2 volunteers (DG, n = 22) and sex-, age- and body mass index-matched non-diabetic controls (CG, n = 22) before, during and after 6MWT.

RESULTS

Before the 6MWT, DG presented lower HRV represented by reduced SDNN [median 28.9 ms² (IQR:18.6-35.4) vs. 45.1 (IQR:39.2-62.67), p < 0.001] and Total Power [median 785 ms² (IQR:256-1264) vs. 1757 ms² (IQR:1006-2912), p = 0.004]. Exercise capacity was reduced in DG [maximal predicted distance (%) = 88.4 ± 6.4 vs. 95.2 ± 11.0%, p = 0.018]. DG demonstrated lower global HRV during recovery and lower parasympathetic drive, represented by reduced RMSSD, during all phases of the 6MWT. Moreover, supine HR (r = -0.32), HR orthostatism (ρ = -0.40), SDNN pre-6MWT (ρ = 0.39), TP pre-6MWT (ρ = 0.38), Valsalva ratio (ρ = 0.39) and 30:15 ratio (ρ = 0.38) were all correlated with maximal walked distance.

CONCLUSIONS

DM2 subjects presented abnormal HRV during and after submaximal exercise. Furthermore, autonomic control impairment in orthostatism, represented by lower global HRV (SDNN, Total power) and lower Ewing's indexes (Valsalva and 30:15 ratios), was associated with lower exercise capacity.

Raising the bar for appropriateness in the care of patients with peripheral artery disease

Advances in endovascular therapy have exponentially increased the number of procedures performed for peripheral artery disease, but public concerns of overuse have placed the vascular community under scrutiny. The appropriateness of care has thus become a focus of discussion within several professional societies, but literature on the topic is limited. This report presents two cases of patients with peripheral artery disease, one patient who did not need revascularization and underwent an intervention and the other who required additional intervention that was not recognized owing to an incomplete diagnostic workup.

Rivaroxaban and Aspirin in Peripheral Vascular Disease: a Review of Implementation Strategies and Management of Common Clinical Scenarios

PURPOSE OF REVIEW

Peripheral artery disease (PAD) affects an estimated 200 million people worldwide and is associated with significant cardiovascular morbidity and mortality. Cardiovascular risk is further increased among individuals with polyvascular disease, where either cerebrovascular or coronary artery disease is present in addition to PAD. In this review, we present common clinical scenarios encountered when managing patients with PAD and provide an evidence-based approach to prescribing optimal antithrombotics in this population.

RECENT FINDINGS

The COMPASS trial recently demonstrated that rivaroxaban 2.5 mg BID + ASA daily significantly reduces major adverse cardiac and limb events in patients with PAD. Despite these advances, morbidity following MALE events remains high. With widespread approval by federal health regulators, the COMPASS regimen should be strongly considered in PAD patients who do not have a high bleeding risk. Implementing the COMPASS regimen in patients with PAD, along with other vascular risk reduction strategies, will have a substantial impact on reducing atherothromboembolic risk in patients with established vascular disease.

Motivating Structured walking Activity in people with Intermittent Claudication (MOSAIC): protocol for a randomised controlled trial of a physiotherapist-led, behavioural change intervention versus usual care in adults with intermittent claudication

INTRODUCTION

Walking exercise is a recommended but underused treatment for intermittent claudication caused by peripheral arterial disease (PAD). Addressing the factors that influence walking exercise may increase patient uptake of and adherence to recommended walking. The primary aim of this randomised controlled trial (RCT) is to evaluate the efficacy of a physiotherapist-led behavioural change intervention on walking ability in adults with intermittent claudication (MOtivating Structured walking Activity in people with Intermittent Claudication (MOSAIC)) in comparison with usual care.

METHODS AND ANALYSIS

The MOSAIC trial is a two-arm, parallel-group, single-blind RCT. 192 adults will be recruited from six National Health Service Hospital Trusts. Inclusion criteria are: aged ≥50 years, PAD (Ankle Brachial Pressure Index ≤0.90, radiographic evidence or clinician report) and intermittent claudication (San Diego Claudication Questionnaire), being able and willing to participate and provide informed consent. The primary outcome is walking ability (6 min walking distance) at 3 months. Outcomes will be obtained at baseline, 3 and 6 months by an assessor blind to group allocation. Participants will be individually randomised (n=96/group, stratified by centre) to receive either MOSAIC or usual care by an independent randomisation service. Estimates of treatment effects will use an intention-to-treat framework implemented using multiple regression adjusted for baseline values and centre.

ETHICS AND DISSEMINATION

This trial has full ethical approval (London-Bloomsbury Research Ethics Committee (17/LO/0568)). It will be disseminated via patient forums, peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ISRCTN14501418.

Association between critical limb ischemia and arterial stiffness measured by brachial artery oscillometry

Background

Elevated arterial stiffness is associated with increased cardiovascular mortality. The relationship between arterial stiffness and critical limb ischemia (CLI) is not well established.

Objectives

The objective of this study is to analyze the relationship between arterial stiffness indices and the degree of limb ischemia measured by the ankle-brachial index (ABI).

Methods

A cross-sectional study comparing patients with CLI and controls. Arterial stiffness was measured using brachial artery oscillometry. The arterial stiffness indices pulse wave velocity (PWV) and augmentation index normalized to 75 beats/min (AIx@75) were determined. Multiple linear regression was applied to identify predictors of arterial stiffness indices.

Results

Patients in the CLI group had higher PWV (12.1±1.9 m/s vs. 10.1±1.9 m/s, p < 0.01) and AIx@75 (31.8±7.8% vs. 17.5±10.8%, p < 0.01) than controls. Central systolic pressure was higher in the CLI group (129.2±18.4 mmHg vs. 115.2±13.1 mmHg, p < 0.01). There was an inverse relationship between AIx@75 and ABI (Pearson coefficient = 0.24, p = 0.048), but there was no relationship between ABI and PWV (Pearson coefficient = 0.19, p = 0.12). In multiple regression analysis, reduced ABI was a predictor of elevated levels of AIx@75 (β = -25.02, p < 0.01).

Conclusions

Patients with CLI have high arterial stiffness measured by brachial artery oscillometry. The degree of limb ischemia, as measured by the ABI, is a predictor of increased AIx@75. The increased AIx@75 observed in CLI may have implications for the prognosis of this group of patients with advanced atherosclerosis.

Ankle-brachial index and peripheral arterial disease: An evaluation including a type 2 diabetes mellitus drug-naïve patients cohort

BACKGROUND

Peripheral arterial disease in patients with type 2 diabetes mellitus is an important risk factor for vascular events. Recommendations about whether ankle-brachial index should be performed differ depending on the source; therefore, it is necessary to re-evaluate the most important risk factors associated with peripheral arterial disease and whether it is useful to perform ankle-brachial index in newly diagnosed and drug-naïve patients with diabetes, independent of age or peripheral arterial disease symptoms.

METHODS

A total of 711 subjects were divided into groups: group 1, 600 type 2 diabetes mellitus patients, symptomatic or not for peripheral arterial disease; group 2, 61 type 2 diabetes mellitus patients newly diagnosed and drug naïve; and group 3, 50 subjects without diabetes. Ankle-brachial index, medical records and physical examination were performed in all patients, accessing cardiovascular risk factors.

RESULTS

Analysing group 1 asymptomatic patient to peripheral arterial disease, we found abnormal ankle-brachial index in 49% (77/156) ⩾50 years and 42% (16/38) <50 years (p = not significant). Considering drug-naïve patients, a peripheral arterial disease prevalence of 39% (24/61) was found; among these, 48% (13/27) were <50 years and 32% (11/34) were ⩾50 years (p = not significant). A forward stepwise regression model was developed, with type 2 diabetes mellitus duration (r² = 0.12) and sedentary lifestyle (r² = 0.14) found as independent variable predictors of severity of peripheral arterial disease, related to ankle-brachial index.

CONCLUSION

We suggest that, in type 2 diabetes mellitus, ankle-brachial index should be measured at diagnosis. In addition, sedentary lifestyle was strongly associated with presence and severity of peripheral arterial disease.

Completion and adherence rates to exercise interventions in intermittent claudication: Traditional exercise versus alternative exercise - a systematic review

BACKGROUND

Intermittent claudication, defined as fatigue or pain in the legs while walking, is a common symptom in peripheral arterial disease. Although exercise effectively improves function and manages symptoms, adherence rates are not ideal. The high levels of pain experienced in traditional exercise programmes may explain the suboptimal adherence. Alternative modalities of exercise can elicit similar benefits to traditional walking exercise. The purpose of this systematic review was to compare completion and adherence rates of exercise programmes in traditional exercise interventions versus alternative exercise interventions among patients with intermittent claudication.

DESIGN

Systematic review.

METHODS

The electronic databases of Medline, SPORTDiscus and CINAHL were searched from the earliest records to March 2018. Search terms were based on 'peripheral artery disease' and 'exercise'. Studies were included if they involved structured exercise and explicitly reported the number of participants that commenced and completed the programme.

RESULTS

The search identified 6814 records based on inclusion criteria. Eighty-four full-text records were reviewed in further detail. Out of the 84 studies, there was a total of 122 separate exercise groups, with 64 groups of 'traditional walking exercise' and 58 groups of 'alternative exercise'. Completion and adherence rates for traditional exercise were 80.8% and 77.6%, respectively. Completion and adherence rates for alternative exercise were 86.6% and 85.5%, respectively.

CONCLUSIONS

The use of alternative modalities of exercise, which have been proved to be as effective as traditional exercise, may offer a solution to the poor participation and adherence rates to exercise in this population.

A Novel, Individualized Exercise Program for Patients with Peripheral Arterial Disease Recovering from Bypass Surgery

The effectiveness of an individual six-month-long physical exercise program in improving health-related quality of life (HRQOL) is unclear. There is some evidence that an individual exercise program can be effective for this aim. The goal of this study was to compare an individual six-month-long physical exercise program for patients with PAD (Peripheral Arterial Disease) with a traditional exercise program and find the effect of these programs on HRQOL and PAD risk factors. The study included patients who underwent femoral–popliteal artery bypass grafting surgery. Patients were divided into three groups: patients participating in an individual six-month-long physical exercise program (group I), in the standard physical activity program (group II), and in a control group (group III), with no subjects participating in rehabilitation II. Results: group I patients had a significantly (p < 0.001) higher HRQOL at 6 months after their surgery compared with groups II and III. The HRQOL scores were significantly (p < 0.05) lower after surgery among older (≥ 65), overweight participants, as well as among patients with diabetes mellitus and cardiovascular diseases when comparing study results with patients without these risk factors.

Home-Based Cardiac Rehabilitation: A Scientific Statement From the American Association of Cardiovascular and Pulmonary Rehabilitation, the American Heart Association, and the American College of Cardiology

Cardiac rehabilitation (CR) is an evidence-based intervention that uses patient education, health behavior modification, and exercise training to improve secondary prevention outcomes in patients with cardiovascular disease. CR programs reduce morbidity and mortality rates in adults with ischemic heart disease, heart failure, or cardiac surgery but are significantly underused, with only a minority of eligible patients participating in CR in the United States. New delivery strategies are urgently needed to improve participation. One potential strategy is home-based CR (HBCR). In contrast to center-based CR services, which are provided in a medically supervised facility, HBCR relies on remote coaching with indirect exercise supervision and is provided mostly or entirely outside of the traditional center-based setting. Although HBCR has been successfully deployed in the United Kingdom, Canada, and other countries, most US healthcare organizations have little to no experience with such programs. The purpose of this scientific statement is to identify the core components, efficacy, strengths, limitations, evidence gaps, and research necessary to guide the future delivery of HBCR in the United States. Previous randomized trials have generated low- to moderate-strength evidence that HBCR and center-based CR can achieve similar improvements in 3- to 12-month clinical outcomes. Although HBCR appears to hold promise in expanding the use of CR to eligible patients, additional research and demonstration projects are needed to clarify, strengthen, and extend the HBCR evidence base for key subgroups, including older adults, women, underrepresented minority groups, and other higher-risk and understudied groups. In the interim, we conclude that HBCR may be a reasonable option for selected clinically stable low- to moderate-risk patients who are eligible for CR but cannot attend a traditional center-based CR program.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Imaging VEGF Receptors and αvβ3 Integrins in a Mouse Hindlimb Ischemia Model of Peripheral Arterial Disease

PURPOSE

To compare targeted imaging of vascular endothelial growth factor (VEGF) receptors vs. α_vβ₃ integrins in a mouse hindlimb ischemia model of peripheral artery disease.

PROCEDURES

Male wild-type (WT) C57BL/6 mice (8- to 10-week old) (n = 24) underwent left femoral artery ligation. The right leg served as control. Five days later, mice were injected with either VEGF receptor targeting [^99mTc]DOTA-PEG-scVEGF ([^99mTc]scV) (n = 8) or with α_vβ₃-targeting tracer [^99mTc]HYNIC-cycloRGD ([^99mTc]RGD) (n = 8) and underwent single photon emission computed tomography (SPECT) x-ray computed tomography imaging. To assess non-specific [^99mTc]scV uptake, six additional mice received a mixture of [^99mTc]scV and 30-fold excess of targeting protein, scVEGF. Tracer uptake as %ID was measured using volumetric regions encompassing the hindlimb muscles and as %ID/g from harvested limb muscles. Double and triple immunofluorescent analysis on tissue sections established localization of α_vβ₃, VEGFR-1, VEGFR-2, as well as certain cell lineage markers.

RESULTS

Tracer uptake, as %ID/g, was higher in ligated limbs of mice injected with [^99mTc]scV compared to ligated hindlimbs in mice injected with [^99mTc]RGD (p = 0.02). The ratio of tracer uptake for ligated/control hindlimb was borderline higher for [^99mTc]scV than for [^99mTc]RGD (p = 0.06). Immunofluorescent analysis showed higher prevalence of VEGFR-1, VEGFR-2, and α_vβ₃, in damaged vs. undamaged hindlimb tissue, but with little co-localization of these markers. Double immunofluorescent staining showed partial co-localization of VEGFR-1, VEGFR-2, and α_vβ_3, with endothelial cell marker FVIII, but not with CD31. Immunostaining for VEGFR-1 and VEGFR-2 additionally co-localized with lineage markers for endothelial progenitor cell and monocytes/macrophages, with a more diverse pattern of co-localization for VEGFR-2.

CONCLUSION

In a mouse hindlimb ischemia model of peripheral artery disease, [^99mTc]scV SPECT tracer-targeting VEGF receptors showed a more robust signal than [^99mTc]RGD tracer-targeting α_vβ₃. Immunofluorescent analysis suggests that uptake of [^99mTc]scV and [^99mTc]RGD in damaged tissue is due to non-overlapping cell populations and reflects different dynamic processes and that enhanced uptake of [^99mTc]scV may be due to the presence of VEGF receptors on additional cell types.

Association of Adding Aspirin to Warfarin Therapy Without an Apparent Indication With Bleeding and Other Adverse Events

IMPORTANCE

It is not clear how often patients receive aspirin (acetylsalicylic acid) while receiving oral anticoagulation with warfarin sodium without a clear therapeutic indication for aspirin, such as a mechanical heart valve replacement, recent percutaneous coronary intervention, or acute coronary syndrome. The clinical outcomes of such patients treated with warfarin and aspirin therapy compared with warfarin monotherapy are not well defined to date.

OBJECTIVE

To evaluate the frequency and outcomes of adding aspirin to warfarin for patients without a clear therapeutic indication for combination therapy.

DESIGN, SETTING, AND PARTICIPANTS

A registry-based cohort study of adults enrolled at 6 anticoagulation clinics in Michigan (January 1, 2010, to December 31, 2017) who were receiving warfarin therapy for atrial fibrillation or venous thromboembolism without documentation of a recent myocardial infarction or history of valve replacement.

EXPOSURE

Aspirin use without therapeutic indication.

MAIN OUTCOMES AND MEASURES

Rates of any bleeding, major bleeding events, emergency department visits, hospitalizations, and thrombotic events at 1, 2, and 3 years.

RESULTS

Of the study cohort of 6539 patients (3326 men [50.9%]; mean [SD] age, 66.1 [15.5] years), 2453 patients (37.5%) without a clear therapeutic indication for aspirin were receiving combination warfarin and aspirin therapy. Data from 2 propensity score-matched cohorts of 1844 patients were analyzed (warfarin and aspirin vs warfarin only). At 1 year, patients receiving combination warfarin and aspirin compared with those receiving warfarin only had higher rates of overall bleeding (cumulative incidence, 26.0%; 95% CI, 23.8%-28.3% vs 20.3%; 95% CI, 18.3%-22.3%; P < .001), major bleeding (5.7%; 95% CI, 4.6%-7.1% vs 3.3%; 95% CI, 2.4%-4.3%; P < .001), emergency department visits for bleeding (13.3%; 95% CI, 11.6%-15.1% vs 9.8%; 95% CI, 8.4%-11.4%; P = .001), and hospitalizations for bleeding (8.1%; 6.8%-9.6% vs 5.2%; 4.1%-6.4%; P = .001). Rates of thrombosis were similar, with a 1-year cumulative incidence of 2.3% (95% CI, 1.6%-3.1%) for those receiving combination warfarin and aspirin therapy compared with 2.7% (95% CI, 2.0%-3.6%) for those receiving warfarin alone (P = .40). Similar findings persisted during 3 years of follow-up as well as in sensitivity analyses.

CONCLUSIONS AND RELEVANCE

Compared with warfarin monotherapy, receipt of combination warfarin and aspirin therapy was associated with increased bleeding and similar observed rates of thrombosis. Further research is needed to better stratify which patients may benefit from aspirin while anticoagulated with warfarin for atrial fibrillation or venous thromboembolism; clinicians should be judicious in selecting patients for combination therapy.

Outcomes After Drug-Coated Balloon Treatment of Femoropopliteal Lesions in Patients With Critical Limb Ischemia: A Post Hoc Analysis From the IN.PACT Global Study

Purpose: To report a post hoc analysis performed to evaluate 1-year safety and efficacy of the IN.PACT Admiral drug-coated balloon (DCB) for the treatment of femoropopliteal lesions in subjects with critical limb ischemia (CLI) enrolled in the IN.PACT Global study (ClinicalTrials.gov identifier NCT01609296). Materials and Methods: Of 1535 subjects enrolled in the study, 156 participants (mean age 71.8±10.4; 87 men) with CLI (Rutherford categories 4,5) were treated with DCB angioplasty in 194 femoropopliteal lesions. This cohort was compared to the 1246 subjects (mean age 68.2±10.0 years; 864 men) with intermittent claudication (IC) treated for 1573 lesions. The CLI cohort had longer lesions (13.9±10.6 vs 11.9±9.4 cm, p=0.009) and a higher calcification rate (76.8% vs 67.7%, p=0.011). Major adverse events [MAE; composite of all-cause mortality, clinically-driven target lesion revascularization (CD-TLR), major (above-ankle) target limb amputation, and thrombosis at the target lesion site], lesion and vessel revascularization rates, and EuroQol-5D were assessed through 1 year. The Kaplan-Meier method was used to estimate survival, CD-TLR, and amputation events; estimates are presented with the 95% confidence intervals (CI). Results: Estimates of 12-month freedom from major target limb amputation were 98.6% (95% CI 96.7% to 100.0%) in subjects with CLI and 99.9% (95% CI 99.8% to 100.0%) in subjects with IC (p=0.002). Freedom from CD-TLR through 12 months was 86.3% (95% CI 80.6% to 91.9%) in CLI subjects and 93.4% (95% CI 91.9% to 94.8%) in IC subjects (p<0.001). The MAE rate through 12 months was higher in CLI subjects (22.5% vs 10.7%, p<0.001), and CLI patients had poorer overall survival (93.0%, 95% CI 88.9% to 97.2%) than IC subjects (97.0%, 95% CI 96.0% to 97.9%, p=0.011). Health status significantly improved in all domains at 6 and 12 months in both groups. Conclusion: Treatment of femoropopliteal disease with DCB in CLI patients is safe through 12-month follow-up, with a low major amputation rate of 1.4%. The rates of MAE and CD-TLR were higher in CLI subjects and reinterventions were required sooner. Additional research is needed to evaluate long-term outcomes of DCB treatment for femoropopliteal lesions in CLI patients.

Lipoprotein(a) apheresis in patients with peripheral arterial disease: rationale and clinical results

Patients with symptomatic peripheral arterial disease (PAD) are at a very high risk of cardiovascular morbidity and mortality. Elevated lipoprotein(a) levels have been shown to be a risk factor for coronary artery disease (CAD) and stroke. More recently elevated lipoprotein(a) levels have also been demonstrated to be associated with prevalent and incident PAD, and even may be a stronger risk factor for PAD compared with CAD. Lipoprotein apheresis is currently the only efficient way to lower lipoprotein(a) levels. Lipoprotein(a) apheresis has been shown to reduce major coronary events in patients with CAD. There is increasing evidence that lipoprotein(a) apheresis also reduces the rate of major adverse limb events such as peripheral revascularizations and amputations in PAD patients, and improves symptoms of PAD such as pain on exertion. This review summarizes the current knowledge on the clinical role of lipoprotein(a) for PAD and the disease-specific effect of lipoprotein(a) apheresis, and suggests indications for screening for and treating of elevated lipoprotein(a) levels in patients with PAD.

Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection

OBJECTIVES

To investigate the diagnostic accuracy of a modified three-material decomposition calcium subtraction (CS) algorithm for the detection of arterial stenosis in dual-energy CT angiography (DE-CTA) of the lower extremity runoff compared to standard image reconstruction, using digital subtraction angiography (DSA) as the reference standard.

METHODS

Eighty-eight patients (53 males; mean age, 65.9 ± 11 years) with suspected peripheral arterial disease (PAD) who had undergone a DE-CTA examination of the lower extremity runoff between May 2014 and May 2015 were included in this IRB-approved, HIPAA-compliant retrospective study. Standard linearly blended and CS images were reconstructed and vascular contrast-to-noise ratios (CNR) were calculated. Two independent observers assessed subjective image quality using a 5-point Likert scale. Diagnostic accuracy for ≥ 50% stenosis detection was analyzed in a subgroup of 45 patients who had undergone additional DSA. Diagnostic accuracy parameters were estimated with a random-effects logistic regression analysis and compared using generalized estimating equations.

RESULTS

CS datasets showed higher CNR (15.3 ± 7.3) compared to standard reconstructions (13.5 ± 6.5, p < 0.001). Both reconstructions showed comparable qualitative image quality scores (CS, 4.64; standard, 4.57; p = 0.220). Diagnostic accuracy (sensitivity, specificity, positive and negative predictive values) for CS reconstructions was 96.5% (97.5%, 95.6%, 90.9%, 98.1) and 93.1% (98.8%, 90.4%, 82.3%, 99.1%) for standard images.

CONCLUSIONS

A modified three-material decomposition CS algorithm provides increased vascular CNR, equivalent qualitative image quality, and greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff on DE-CTA compared with standard image reconstruction.

KEY POINTS

• Calcified plaques may lead to overestimation of stenosis severity and false positive results, requiring additional invasive digital subtraction angiography (DSA). • A modified three-material decomposition algorithm for calcium subtraction provides greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff compared with standard image reconstruction. • The application of this algorithm in patients with heavily calcified vessels may be helpful to potentially reduce inconclusive CT angiography examinations and the need for subsequent invasive DSA.

Antithrombotics in stable peripheral artery disease

Patients with peripheral artery disease (PAD) are at high risk for ischemic cardiovascular complications. While single antiplatelet therapy (SAPT), predominantly aspirin, has long been the standard antithrombotic treatment in stable PAD, there have now been greater than 40,000 PAD patients randomized to varying antiplatelet and/or anticoagulant regimens. In this review, we provide a summary of the current evidence for antithrombotics in stable PAD, focusing on the rates of major adverse cardiovascular events (MACE), major adverse limb events (MALE), and major bleeding. SAPT has a limited role in the treatment of asymptomatic PAD, particularly in the absence of concomitant coronary artery disease. In symptomatic PAD, SAPT is effective in preventing MACE, though treatment with a thienopyridine appears marginally superior to aspirin. Dual antiplatelet therapy (DAPT) suggests benefit over SAPT in reducing MACE and MALE, though studies to date are not conclusive and/or are associated with excess major bleeding. Combining moderate to high intensity vitamin K antagonists with antiplatelet therapy does not reduce MACE or MALE and increases life-threatening bleeding. Rivaroxaban 2.5 mg BID in addition to aspirin reduces the incidence of both MACE and MALE as compared to aspirin alone, without increasing life-threatening bleeding. This regimen is associated with a reduced severity of MALE when it does occur. Comparisons across antithrombotic trials in PAD are challenging given the heterogeneity of patient populations and the differing assessment of outcomes. The vascular medicine practitioner can reduce ischemic cardiac and limb events, as well as minimize life-threatening bleeding, by choosing the optimal antithrombotic regimen in their PAD patients.

IN.PACT™ Admiral™ drug-coated balloons in peripheral artery disease: current perspectives

Endovascular therapy has evolved as a main treatment option especially in patients with short (<25 cm) femoropopliteal lesion. The latest guideline recommends the use of drug-eluting devices (both drug-coated balloons [DCBs] and drug-eluting stents) in short femoro-popliteal lesions as class IIb recommendation. DCB usage is also recommended for in-stent restenosis lesions (class IIb). DCBs are a more attractive treatment option because the lack of metal prosthesis allows for more flexibility in future treatment options including the option of treating nonstenting zones, previously DCB-treated zones with DCBs again. The IN.PACT™ Admiral™ DCB has shown promising clinical performance in several randomized control trials and global registries, and is currently the market DCB leader for the treatment of femoropopliteal lesions with more than 200,000 patients treated thus far. Currently, more than 10 DCBs have received Conformité Européene mark for the treatment of femoropopliteal atherosclerotic disease. Three of these (including IN.PACT Admiral DCBs) have also received Food and Drug Administration approval in the USA. However, some Conformité Européene-marked DCBs have failed to show consistent results in their clinical studies suggesting all DCBs are not created equal. Each DCB is unique (ie, drug type, drug dose, crystallinity, and excipient) with different clinical outcomes. In the current review, we will focus on the preclinical and clinical results of not only IN.PACT Admiral DCB, but also the other currently available DCBs.

Clinical Assessment of Peripheral Arterial Disease in the Office: What Do the Guidelines Say?

Lower extremity peripheral arterial disease (PAD) is the manifestation of atherosclerotic disease within the lower extremities. The presentation of PAD is diverse ranging from asymptomatic disease to claudication or to debilitating rest pain, nonhealing ulcers, and gangrene. PAD is associated with significant morbidity, mortality, and healthcare costs. Proper diagnosis and management of PAD is important so as to maintain quality of life and reduce the risk of cardiovascular disease and adverse limb events such as amputation. This document provides a comprehensive outpatient approach to the clinical assessment of PAD that includes risk factors, diagnosis, treatment, and follow-up options.

Treatment Strategies for the Claudicant

Peripheral arterial disease (PAD) is a prevalent, morbid, and mortal disease. Claudication represents an early, yet common manifestation of PAD. A clinical history and physical examination combined with an ankle-brachial index can help make a diagnosis of claudication. Due to the polyvascular nature of the underlying atherosclerosis, PAD is often associated with heart disease and stroke. Although health implications of PAD derive from both its limb and cardiovascular manifestations, claudication is life-threatening, less limb-threatening. Medical modification of cardiovascular risk factors and exercise are the cornerstone in the treatment of claudication. Revascularization in claudication is focused at improvement in claudication symptoms and functional status, rather than aggressive attempts at limb salvage. The aim of this article is to summarize the strategies in the treatment of claudication, to serve as a concise and informative reference for physicians who are managing these patients. A framework of the decision-making process in the management of patients with claudication is shown, which can be applied in clinical practice.

Noninvasive Arterial Testing: What and When to Use

Peripheral arterial disease (PAD) represents a growing public health issue that continues to be underdiagnosed. In its most severe form, critical limb ischemia, it contributes to expanding morbidity with minor and major limb amputations. PAD is strongly associated with increased mortality, as it is known to be concomitant with coronary and cerebrovascular disease. Diagnosis of PAD relies on noninvasive arterial testing, a class of tests that can provide physiologic or morphologic information. Physiologic tests such as ankle-brachial index, toe-brachial index, pulse volume recordings, and arterial duplex evaluation are the mainstay of gateway evaluation and surveillance. Morphologic exams such as computer tomographic angiography and magnetic resonance angiography are appropriate for preprocedural anatomic evaluation in patients with established vascular disease. This review focuses on physiologic exams.

Radial Access for Lower Extremity Peripheral Arterial Interventions: Do We Have the Tools?

The benefits of transradial arterial access (TRA) versus transfemoral arterial access (TFA) have been extensively described in the literature; however, TFA remains the predominant access site choice in the management of peripheral arterial disease (PAD). There are still significant unmet needs for operators wishing to provide the same effective interventions for lower extremity PAD via TRA as with TFA. This article provides an up-to-date review of the literature and devices currently available for operators wishing to treat lower extremity PAD via TRA and the limitations they may face.

The enhancement of serotonin-induced contraction of rat femoral artery is mediated by angiotensin II release from intact endothelium

We have performed an in vitro study on isolated intact or denuded femoral artery (FA) of healthy, diabetic, and/or rats submitted to the FA occlusion. The aim was to determine the contribution of endothelium and endothelial dysfunction (ED) on serotonin-induced action in FA. Further, the contribution of angiotensin II and cyclooxygenase products of arachidonic acid was investigated. A marker of ED, vWF was measured in animal serum. Serotonin induced contraction-dependent contraction of isolated FA, which was increased in preparations with endothelium. Pathological conditions such as endothelial denudation, nicotine-induced ED, diabetes or occlusion of FA reduced serotonin-induced contraction. Comparable reduction of serotonin-induced contraction was achieved after inhibition of AT1 receptors with losartan in isolated FA with intact endothelium. Our results demonstrate that angiotensin II contributes to the enhancement of serotonin-induced contraction of femoral arteries with intact endothelium. This increase is attenuated by endothelium removal, nicotine treatment, vascular occlusion, and/or hyperglycemia.

Critical appraisal of international guidelines for the screening and treatment of asymptomatic peripheral artery disease: a systematic review

Background

Peripheral artery disease (PAD) is often asymptomatic but increases the risk of developing cardiovascular events. Due to the uncertainties regarding the quality of related guidelines and a lack of clear-cut evidence, we performed a systematic review and critical appraisal of these guidelines to evaluate their consistency of the recommendations in asymptomatic PAD population.

Methods

Guidelines in English between January 1st, 2000 to December 31th, 2017 were screened in databases including Medline via PubMed, EMBASE, the G-I-N International Guideline Library, the National Guidelines Clearinghouse, the Canadian Medication Association Infobase and the National Library for Health. Those guidelines containing recommendations on screening and treatment for asymptomatic PAD were included, and three reviewers evaluated the quality of the guidelines using Appraisal of Guidelines Research and Evaluation (AGREE) II instrument. Related recommendations were then fully extracted and compared by two reviewers.

Results

Fourteen guidelines were included finally and the AGREE scores ranged from 39 to 73%. Most of included guidelines scored low in Rigor of development and Editorial independence, and only two guidelines (ACCF/AHA, AHA/ACC) reached the standard on Conflict of Interest from Institute of Medicine (IOM). Eight guidelines recommended screening at different strength while the others found insufficient evidence or were against screening. Conflicting recommendations on treatment were found in the target value of the lipid lowering and antiplatelet therapy. The treatment policies in three guidelines (BWG, CEVF, ESC) appeared more aggressive, but they had low transparency between guideline developer and industry or did not reach the standard of IOM.

Conclusions

Current guidelines on asymptomatic PAD varied in the methodological quality and fell short of the standard in the rigor of development and editorial independence. Conflicting recommendations were found both on the screening and treatment. More effort is needed to provide clear-cut evidences with high quality and transparency among guideline developer and industry.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0960-8) contains supplementary material, which is available to authorized users.

Sortilin levels are associated with peripheral arterial disease in type 2 diabetic subjects

BACKGROUND

Sortilin is a 95-kDa protein which has recently been linked to circulating cholesterol concentration and lifetime risk of developing significant atherosclerotic disease. Sortilin is found inside different cell types and circulating in blood. Higher circulating sortilin concentration has been found in patients with coronary atherosclerosis compared to control subjects. Sortilin concentration is influenced by statin therapy.

METHODS

We enrolled statin-naïve subjects with type 2 diabetes mellitus and we performed a cross-sectional study to evaluate the association between sortilin levels and the presence of clinically significant lower limb peripheral artery disease (PAD) in a population of statin-free diabetic subjects.

RESULTS

Out of the 154 patients enrolled in our study, 80 patients were free from PAD, while 74 had clinically significant PAD. Sortilin concentration was significantly higher in the latter group compared to the former (1.61 ± 0.54 ng/mL versus 0.67 ± 0.30 ng/mL, P < 0.01) and there was a trend toward increased sortilin levels as disease severity increased. The association of sortilin levels with PAD remained after adjusting for major risk factors in a multivariate analysis.

CONCLUSIONS

We showed that sortilin is significantly and independently associated with the presence of lower limb PAD in a statin-free diabetic population and it may be a promising marker for clinically significant atherosclerosis of the lower limbs. Further studies are needed to confirm this finding and to evaluate its clinical usefulness.

Natural remodeling of the distal anastomosis of an above-knee femoropopliteal bypass depicted by CT angiography of lower limbs improves geometry of the reconstruction

The geometry of the distal anastomosis of a femoropopliteal bypass influences local hemodynamics and formation of intimal hyperplasia. We hypothesized that the distal anastomosis of an above-knee femoropopliteal bypass undergoes remodeling that results in displacement of the original course of the popliteal artery and change in the anastomosis angle. We identified 43 CT angiography examination with proximal femoropopliteal bypass and either a preserved contralateral popliteal artery or previous CTA before construction of the bypass for comparison. In these examinations, we measured the displacement distance and angle at the level of the distal anastomosis and compared these measurements with clinical and imaging data. The displacement distance was 8.8+/-4.9 mm (P<0.0001) and the displacement angle was -1° (IQR=44°). The angle between the inflow and outflow artery was 153+/-16° (P<0.0001). There was a negative association between the displacement angle and the angle between the bypass and the outflow artery (r=-0.318, P=0.037). Patients with reversed venous grafts had a greater displacement of the anastomosis (14.7+/-3.0 mm) than patients with prosthetic grafts (8.0+/-4.5 mm, P=0.0011). We conclude that construction of a distal anastomosis of proximal femoropopliteal bypass results in displacement of the original course of the popliteal artery towards the bypass and this effect is more pronounced in reversed venous grafts.

Risk of Death Following Application of Paclitaxel-Coated Balloons and Stents in the Femoropopliteal Artery of the Leg: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background Several randomized controlled trials ( RCT s) have already shown that paclitaxel-coated balloons and stents significantly reduce the rates of vessel restenosis and target lesion revascularization after lower extremity interventions. Methods and Results A systematic review and meta-analysis of RCT s investigating paclitaxel-coated devices in the femoral and/or popliteal arteries was performed. The primary safety measure was all-cause patient death. Risk ratios and risk differences were pooled with a random effects model. In all, 28 RCT s with 4663 patients (89% intermittent claudication) were analyzed. All-cause patient death at 1 year (28 RCT s with 4432 cases) was similar between paclitaxel-coated devices and control arms (2.3% versus 2.3% crude risk of death; risk ratio, 1.08; 95% CI, 0.72-1.61). All-cause death at 2 years (12 RCT s with 2316 cases) was significantly increased in the case of paclitaxel versus control (7.2% versus 3.8% crude risk of death; risk ratio, 1.68; 95% CI, 1.15-2.47; -number-needed-to-harm, 29 patients [95% CI , 19-59]). All-cause death up to 5 years (3 RCT s with 863 cases) increased further in the case of paclitaxel (14.7% versus 8.1% crude risk of death; risk ratio, 1.93; 95% CI , 1.27-2.93; -number-needed-to-harm, 14 patients [95% CI , 9-32]). Meta-regression showed a significant relationship between exposure to paclitaxel (dose-time product) and absolute risk of death (0.4±0.1% excess risk of death per paclitaxel mg-year; P<0.001). Trial sequential analysis excluded false-positive findings with 99% certainty (2-sided α, 1.0%). Conclusions There is increased risk of death following application of paclitaxel-coated balloons and stents in the femoropopliteal artery of the lower limbs. Further investigations are urgently warranted. Clinical Trial Registration URL : www.crd.york.ac.uk/PROSPERO . Unique identifier: CRD 42018099447.

Association Between Prevalence of Peripheral Artery Disease and Radiation Exposure in the Atomic Bomb Survivors

Background Past reports suggested that total-body irradiation at 0.5 to 1.0 Gy could be responsible for atherosclerosis. Peripheral artery disease ( PAD ) is a manifestation of systematic atherosclerosis. Whether the consequences of a low-to-moderate dose of radiation include increased risk of PAD remains to be determined. The purpose of this study was to examine the association between radiation exposure and prevalence of PAD among Japanese atomic bomb survivors. Methods and Results Radiation exposure from the atomic bombing was assessed in 3476 participants (41.1% men, mean age 74.8 years with SD 6.4 years) with a cross-sectional survey in 2010 to 2014. Left- and right-side ankle-brachial indexes and upstroke time ( UT ) were obtained using oscillometric VP -2000. PAD was defined as an ankle-brachial index of 1.0 or less or a prior history related to revascularization. UT was considered a sensitive marker of early-stage PAD . Association between radiation exposure and PAD or UT was assessed using multivariable regression analyses with adjustment for potential confounding factors. Of 3476 participants, 79 (2.3%) were identified as having prevalent PAD . Multivariate logistic regression analysis indicated that radiation dose was unrelated to PAD prevalence (odds ratio, 0.83; 95% confidence interval [0.57-1.21]). UT appeared to increase with radiation dose, but the increase was not statistically significant (1.09 ms/Gy; 95% confidence interval [-0.17 to 2.36]). Conclusions We found no clear association of radiation dose with PAD , but it remains to be determined whether UT is associated with radiation dose.

Association of sex and height with a lower ankle brachial index in the general population

The ankle-brachial index (ABI) is a predictor of cardiovascular events, mortality and functional status. Some studies have noted a higher prevalence of peripheral artery disease in females compared to males. Differences in height might account for these observed sex differences, but findings are conflicting. The 2003-2004 National Health and Nutrition Examination Survey (NHANES) cohort includes participants from 15 geographic locations, selected annually to represent the general population. Sample-weighted multivariable linear and logistic regression modeling was performed with ABI as the dependent variable and height and sex as primary exposure variables of interest. There were 3052 participants with ABI data (mean age 57 years, 51% female). The mean (±SE) ABI was 1.09 (±0.006) and 1.13 (±0.005) for females and males, respectively ( p < 0.0001). Shorter height was associated with a low ABI (OR 0.91 per 4 cm, 95% CI: 0.86-0.96; p=0.001). In a fully adjusted model, female sex was associated with a low ABI (OR 1.34, 95% CI: 1.04-1.72; p=0.025) independent of height and traditional cardiovascular disease (CVD) risk factors. Age, diabetes, tobacco use, known CVD, hypertension and race were associated with a low ABI (all p < 0.001). The ABI was 0.03 lower in females than in males in the general population and in a healthy cohort. Lower ABI values in healthy females do not appear to be due to occult vascular disease but rather a normal phenomenon with some contribution from height. Therefore, population sex-specific ABI thresholds should be utilized in the diagnosis of peripheral artery disease to account for these intrinsic differences.

Dual Antiplatelet Therapy Duration: Reconciling the Inconsistencies

Dual antiplatelet therapy (DAPT) prevents recurrent ischemic events after an acute coronary syndrome (ACS) as well as stent thrombosis (ST) in patients with prior stent implantation. Nevertheless, these benefits are counterbalanced by a significant bleeding hazard, which is directly related to the treatment duration. Although DAPT has been extensively studied in numerous clinical trials, optimal treatment duration is still debated, mostly because of apparent inconsistencies among studies. Shortened treatment duration of 6 or 3 months was shown to mitigate bleeding risk compared with consensus-grounded 12-month standard duration, without any apparent excess of ischemic events. However, recent trials showed that a >12-month course of treatment reduces ischemic events but increases bleeding compared with 12 months. The inconsistent benefit of a longer DAPT course compared with shorter treatment durations is puzzling, and requires a careful appraisal of between-studies differences. We sought to summarize the existing evidence aiming at reconciling apparent inconsistencies among these studies, as well as thoroughly discuss the possible increased risk of fatal events associated with long-term DAPT. Benefits and risks of prolonging or shortening DAPT duration will be discussed, with a focus on treatment individualization. Finally, we will provide an outlook for possible future directions in the field.

Limb Ischemia in a Patient with Hyperosmolar Hyperglycemic State

A 61-year-old male with a recent diagnosis of pemphigus vulgaris was brought to the emergency department for altered mental status. He had recently started taking prednisone to manage his autoimmune disease and had a progressive decline in his mental status along with decreased oral intake. Evaluation revealed hyperosmolar hyperglycemic state (HHS) and occlusive arterial thrombosis, a rare but known complication of HHS. He was resuscitated aggressively with intravenous fluids, insulin, and heparin and admitted to the intensive care unit. Emergency physicians should remain vigilant for ischemic complications in patients with HHS. Early recognition and treatment can reduce the morbidity and mortality associated with this endocrine emergency.

A Comparison of Outcomes After Lower Extremity Bypass and Repeat Endovascular Intervention Following Failed Previous Endovascular Intervention for Critical Limb Ischemia

The optimal approach for repeat revascularization after failed endovascular intervention for critical limb ischemia (CLI) is unclear. This study compared major adverse limb events (MALEs) and major adverse cardiac events (MACEs) between lower extremity bypass (LEB) and repeat endovascular intervention (REI) in patients with prior failed ipsilateral endovascular intervention. American College of Surgeons National Surgical Quality Improvement Program database identified patients undergoing LEB and endovascular intervention for CLI from 2011 to 2014. We compared REI to LEB with single-segment saphenous vein (LEB-SV) and LEB alternative conduit (LEB-alt). Primary outcomes were 30-day MALE and MACE. Multivariate analysis identified independent predictors of MALE and MACE. A total of 1567 revascularizations were performed after failed ipsilateral endovascular intervention (REI: 683 [43.5%], LEB-SV: 570 [36.4%], LEB-alt: 314 [20.0%]). There were 994 and 573 suprageniculate and infrageniculate revascularizations, respectively. Major adverse cardiac events were significantly lower after REI compared to LEB (REI: 15 [2.2%], LEB-SV: 33 [5.8%], LEB-alt: 21 [6.7%], P < .001). Major adverse limb event were not different between groups ( P = .99). In patients with CLI presenting after failed endovascular intervention, REI is associated with lower MACE without an increased risk of MALE compared to LEB. When the anatomy is amenable, REI should be considered a less morbid first option.

Association of Blood Pressure Measurements With Peripheral Artery Disease Events

BACKGROUND

Current guidelines recommend treating hypertension in patients with peripheral artery disease (PAD) to reduce the risk of cardiac events and stroke, but the effect of reducing blood pressure on lower extremity PAD events is largely unknown. We investigated the association of blood pressure with lower extremity PAD events using data from the ALLHAT trial (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial).

METHODS

ALLHAT investigated the effect of different antihypertensive medication classes (chlorthalidone, amlodipine, lisinopril, or doxazosin) on cardiovascular events. With the use of these data, the primary outcome in our analysis was time to first lower extremity PAD event, defined as PAD-related hospitalization, procedures, medical treatment, or PAD-related death. Given the availability of longitudinal standardized blood pressure measurements, we analyzed systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure as time-varying categorical variables (reference categories 120-129 mm Hg for SBP, 70-79 mm Hg for DBP, and 45-54 mm Hg for pulse pressure) in separate models. We used extended Cox regression with death as a competing risk to calculate the association of each blood pressure component with PAD events, and report the results as subdistribution hazard ratios and 95% CIs.

RESULTS

The present analysis included 33 357 patients with an average age of 67.4 years, 53.1% men, 59.7% white race, and 36.2% with diabetes mellitus. The median baseline blood pressure was 146/84 mm Hg. Participants were followed for a median of 4.3 (interquartile range, 3.6-5.3) years, during which time 1489 (4.5%) had a lower extremity PAD event, and 4148 (12.4%) died. In models adjusted for demographic and clinical characteristics, SBP <120 mm Hg was associated with a 26% (CI, 5%-52%; P=0.015) higher hazard and SBP≥160 mm Hg was associated with a 21% (CI, 0%-48%; P=0.050) higher hazard for a PAD event, in comparison with SBP 120 to 129 mm Hg. In contrast, lower, but not higher, DBP was associated with a higher hazard of PAD events: for DBP <60 mm Hg (hazard ratio, 1.72; CI, 1.38-2.16). Pulse pressure had a U-shaped association with PAD events.

CONCLUSIONS

In this reanalysis of data from ALLHAT, we found a higher rate of lower extremity PAD events with higher and lower SBP and pulse pressure and with lower DBP. Given the recent revised blood pressure guidelines advocating lower SBP targets for overall cardiovascular risk reduction, further refinement of optimal blood pressure targets specific to PAD is needed.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT00000542.

Comparison of leg loader and treadmill exercise for evaluating patients with peripheral artery disease

The exercise ankle-brachial index (ABI) helps diagnose lower extremity peripheral artery disease (PAD). Patients with comorbidities may be unable to perform treadmill exercise, the most common stress loading test. While the active pedal plantar flexion (APP) test using the leg loader, simple and easy stress loading device, could be an alternative, there are no data comparing the leg loader and treadmill exercise. Therefore, we aimed to compare APP using the leg loader and treadmill exercise to evaluate PAD. A total of 27 patients (54 limbs) diagnosed with PAD with intermittent claudication and considered for angiography and/or endovascular treatment were recruited prospectively, and both the leg loader and treadmill were performed. There was a strong correlation (r = 0.925, p < 0.001) between the leg loader ABI and treadmill ABI; however, the decrease rate of the leg loader ABI was significantly less than that of treadmill ABI (14.0% [5.6, 30.1] vs. 25.8% [6.1, 53.1], p < 0.001). The number of patients who terminated the exercise prematurely due to dyspnea was four during the treadmill and zero during the leg loader. There was a good correlation between the leg loader ABI and treadmill ABI. Although leg loader, a simple, safe, and easy method, could be an alternative to diagnose PAD, further studies are needed to evaluate the diagnostic value of the leg loader in patients with borderline ABI or those unable to perform the treadmill.

The perfusion index is a useful screening tool for peripheral artery disease

The number of people with peripheral artery disease (PAD) has been increasing globally; therefore, it is important to explore more options to screen patients who are at a risk of developing PAD. The perfusion index (PI) represents the degree of circulation through the peripheral tissues and is measured noninvasively. We investigated the correlation between the PI and ankle-brachial index (ABI) to explore whether the PI could be used a screening tool for PAD. This cross-sectional study included 390 patients. We measured the ABI and PI for all patients. The median ABI value was 1.06 (0.92-1.13); the PI was 1.7% (0.9-3.5). The PI was higher in men than in women (P < 0.0001). The PI was positively correlated with the estimated glomerular filtration rate and ABI in both men and women. The sensitivity and specificity of the PI to predict PAD (ABI ≤0.9) were 90.0% and 80.3%, respectively, and the cutoff PI value was 1.5% in men. The sensitivity and specificity of the PI to predict PAD were 82.1% and 79.2%, respectively, and the cutoff PI value was 1.1% in women. PI could be a reliable screening tool for diagnosing PAD because it does not restrict the patient's mobility, can be completed in a short time period, and is associated with reduced costs.

The optimal duration of dual antiplatelet therapy after coronary stent implantation: to go too far is as bad as to fall short

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is key for secondary prevention of recurrent coronary ischemic events and stent thrombosis. For this purpose, DAPT showed superior efficacy compared to aspirin alone, but it is also associated with an increased risk of major, and potentially fatal, bleeding. Hence, while secondary prevention with aspirin monotherapy is generally maintained for an indefinite period, the duration of DAPT after the index event is still debated. Multiple trials have challenged the guideline recommended standard of care of 12 months of DAPT duration. These studies tested on one side a treatment reduction to 6 or 3 months, and on the other side an extension of treatment beyond 12 months in order to define the optimal DAPT duration maximizing the anti-ischemic protection and minimizing bleeding. In this document we sought to summarize the existing evidence from more than 18 randomized controlled trials in the field, and discuss the benefit and risks of prolonging/shortening DAPT duration. In addition, a specific focus on treatment individualization will outline the current, evidence-based, decision-making process for optimal DAPT duration selection after coronary stenting.

Challenges in recruitment of persons with peripheral artery disease for exercise studies

This article describes feasibility of direct and indirect recruitment methods for exercise studies designed for older adults with peripheral artery disease (PAD). Recruitment of older adults with PAD for participation in exercise studies has been particularly challenging. Age, risk factors, and comorbid conditions affect physical activity in older adults with PAD. Barriers to exercise, such as safety, health, and age-related changes, contribute to lack of participation in exercise studies. Various direct and indirect recruitment approaches and participant responses, along with reasons for nonparticipation, are categorized into participant demographic, community, and research-related barriers. At a cost of $1,330.00, indirect recruitment strategies of social marketing and community outreach resulted in two referrals and no enrollments. Recruitment-site champions and education resulted in no referrals and no enrollments. Direct recruitment approaches such as health system recruitment and referrals paired with flyers resulted in 44 referrals and one enrollment. Only one referral was obtained from a physician practice. Reasons for nonparticipation included lack of follow-up, presence of one or more exclusion criteria, lack of transportation, and comorbid disease burden that limited activity. Community- and research-related barriers included recruitment competition for other studies, budget limitations, lack of recruitment staff, and strict inclusion/exclusion criteria. Successful recruitment of older adults with PAD for participation in exercise clinical trials may require substantial time and budget. Interventions to address identified barriers such as personal attitudes and socioeconomic factors, lack of social support, and lack of transportation, combined with community factors such as rural location, and research study design considerations may facilitate recruitment efforts.

Determinants of Long-Term Outcomes and Costs in the Management of Critical Limb Ischemia: A Population-Based Cohort Study

Background The optimal treatment for critical limb ischemia remains controversial owing to conflicting conclusions from previous studies. Methods and Results We obtained administrative claims on Medicare beneficiaries with initial critical limb ischemia diagnosis in 2011. Clinical outcomes and healthcare costs over 4 years were estimated among all patients and by first treatment (endovascular revascularization, surgical revascularization, or major amputation) in unmatched and propensity-score-matched samples. Among 72 199 patients with initial primary critical limb ischemia diagnosis in 2011, survival was 46% (median survival, 3.5 years) and freedom from major amputation was 87%. Among 9942 propensity-score-matched patients (8% rest pain, 26% ulcer, and 66% gangrene), survival was 38% with endovascular revascularization (median survival, 2.7 years), 40% with surgical revascularization (median survival, 2.9 years), and 23% with major amputation (median survival, 1.3 years; P<0.001 for each revascularization procedure versus major amputation). Corresponding major amputation rates were 6.5%, 9.6%, and 10.6%, respectively ( P<0.001 for all pair-wise comparisons). The cost per patient year during follow-up was $49 700, $49 200, and $55 700, respectively ( P<0.001 for each revascularization procedure versus major amputation). Conclusions Long-term survival and cost in critical limb ischemia management is comparable between revascularization techniques, with lower major amputation rates following endovascular revascularization. Primary major amputation results in shorter survival, higher risk of subsequent major amputation, and higher healthcare costs versus revascularization. Results from this observational research may be susceptible to bias because of the influence of unmeasured confounders.

Mesenchymal Stem Cell Sheets Exert Antistenotic Effects in a Rat Arterial Injury Model

Restenosis after catheter or surgical intervention substantially affects the prognosis of arterial occlusive disease. Mesenchymal stem cells (MSCs) may have antistenotic effects on injured arteries. MSC transplantation from the adventitial side of an artery is safer than endovascular transplantation but has not been extensively examined. In this study, a rat model of femoral artery injury was used to compare the antistenotic effects of transplanted cell sheets and transplanted cell suspensions. Rat adipose-derived stem cells (ASCs) were used as the source of MSCs. For both cell sheets and suspensions, 6 × 10⁶ MSCs were transplanted on the day of arterial injury. MSC sheets attenuated neointimal hyperplasia more than MSC suspensions (intima-to-media ratio in hematoxylin/eosin-stained sections: 0.55 ± 0.13 vs. 1.14 ± 0.12; p < 0.05). Cell engraftment (assessed by immunohistochemistry or bioluminescence imaging of luciferase-expressing cells), arterial re-endothelialization (evaluated by immunohistochemical staining for rat endothelial cell antigen-1), and restriction of vascular smooth muscle cell proliferation in the neointima (double-staining of alpha-smooth muscle actin and phospho-histone H3) were greater when MSC sheets were applied than when MSC suspensions were used. In conclusion, MSC sheets exhibited better antistenotic and cell engraftment properties than MSC suspensions. MSC sheet transplantation from the adventitial side is a promising therapy for prevention of arterial restenosis.

Peripheral vascular interventional advances in 2017

Aim of this review is to inform major clinical trials in peripheral vascular interventions in the year of 2017.