Network Meta-Analysis Comparing the Outcomes of Treatments for Intermittent Claudication Tested in Randomized Controlled Trials

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

PURPOSE

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

METHODS

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

FINDINGS

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

IMPLICATIONS

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

Impact of walk advice alone or in combination with supervised or home-based structured exercise on patient-reported physical function and generic and disease-specific health related quality of life in patients with intermittent claudication, a secondary analysis in a randomized clinical trial

BACKGROUND

Supervised exercise is an integral part of the recommended first-line treatment for patients with intermittent claudication (IC). By reflecting the patients' perspectives, patient-reported outcome measurements provide additional knowledge to the biomedical endpoints and are important outcomes to include when evaluating exercise interventions in patients with IC. We aimed to evaluate the one-year impact of three strategies: unsupervised Nordic pole walk advice (WA), WA + six months of home-based structured exercise (HSEP) or WA + six months of hospital-based supervised exercise (SEP) on health-related quality of life and patient-reported physical function in patients with IC.

METHODS

This secondary exploratory analysis of a multi-center, randomized clinical trial compared three exercise strategies. The primary outcome of the secondary analysis was the one-year change in the 36-Item Short-Form (SF-36). Secondary outcomes were three- and six-months SF-36 changes alongside three, six- and 12-months changes in the disease-specific Vascular Quality of Life instrument (VascuQoL) and the Patient-Specific Functional Scale (PSFS). The Kruskal-Wallis test with Bonferroni-adjusted post-hoc tests were used for between-group comparisons. Effect size calculations were used to describe the size of observed treatment effects, and the clinical meaningfulness of observed changes in the VascuQoL summary score at one year was studied using established minimally important difference (MID) thresholds.

RESULTS

A total of 166 patients with IC, mean age: 72.1 (SD 7.4) years, 41% women, were randomized. No significant between-group differences were observed over time for the SF-36 or the PSFS scores whereas some significant between-group differences were observed in the VascuQoL domain and summary scores over time, favoring SEP and/or HSEP over WA. The observed SF-36 and VascuQoL domain and summary score effect sizes were small to moderate, and many domain score effect sizes also remained unchanged over time. A significantly higher proportion of the patients in the SEP group reached the VascuQoL summary score MID of improvement in one year.

CONCLUSION

Clinically important improvements were observed in SEP using the VascuQoL, while we did not observe any significant between-group differences using the SF-36. Whereas effect sizes for the observed changes over time were generally small, a significantly higher proportion of patients in SEP reached the VascuQoL MID of improvement.

TRIAL REGISTRATION

NCT02341716, January 19, 2015 (retrospectively registered).

Focus on the Prevention of Acute Limb Ischemia: Centrality of the General Practitioner from the Point of View of the Internist

The thrombotic mechanism, being common to peripheral arterial disease (PAD), acute myocardial infarction (AMI), and stroke, is responsible for the highest number of deaths in the western world. However, while much has been done for the prevention, early diagnosis, therapy of AMI and stroke, the same cannot be said for PAD, which is a negative prognostic indicator for cardiovascular death. Acute limb ischemia (ALI) and chronic limb ischemia (CLI) are the most severe manifestations of PAD. They both are defined by the presence of PAD, rest pain, gangrene, or ulceration and we consider ALI if symptoms last less than 2 weeks and CLI if they last more than 2 weeks. The most frequent causes are certainly atherosclerotic and embolic mechanisms and, to a lesser extent, traumatic or surgical mechanisms. From a pathophysiological point of view, atherosclerotic, thromboembolic, inflammatory mechanisms are implicated. ALI is a medical emergency that puts both limb and the patient's life at risk. In patients over age 80 undergoing surgery, mortality remains high reaching approximately 40% as well as amputation approximately 11%. The purpose of this paper is to summarize the scientific evidence on the possibilities of primary and secondary prevention of ALI and to raise awareness among doctors involved in the management of ALI, in particular by describing the central role of the general practitioner.

Vascular Inflammatory Markers as Predictors of Peripheral Arterial Disease Patients' Quality-of-Life Changes after Endovascular Treatment

The association between chronic inflammation and depression, anxiety, anhedonia, and quality of life (QoL) has been recently emphasized. However, the pathophysiology of this relationship remains unsolved. This study aims to assess the dependence between vascular inflammation represented by eicosanoid concentration and quality of life in patients with peripheral arterial disease (PAD). A total of 175 patients undergoing endovascular treatment due to lower limbs ischemia were covered with eight years of observation after the endovascular procedure, including ankle-brachial index (ABI), color Doppler ultrasound examination, urinary leukotriene E4 (LTE4), thromboxane B2 (TXB2) and 5-Hydroxyeicosatetraenoic acid (5-HETE) measurement and quality-of-life assessment with VascuQol-6. The baseline concentrations of LTE4 and TXB2 reversely correlated with preoperative VascuQol-6 and were predictive of the postoperative values of VascuQol-6 at each follow-up. At every follow-up timepoint, the results of VascuQol-6 reflected the LTE4 and TXB2 concentrations. Higher concentrations of LTE4 and TXB2 were correlated with lower life quality during the next follow-up meeting. Changes in VascuQol-6 at eight years vs. preoperative values were reversely related to the preoperative concentrations of LTE4 and TXB2. This is the first study to confirm that changes in life quality in PAD patients undergoing endovascular treatment are highly dependent on eicosanoid-based vascular inflammation.

Which nutritional prognosis is better? comparison of the three most commonly performed bariatric surgeries: A systematic review and network meta-analysis

Background

Obesity is one of the most important public health conditions in the world, and surgical intervention is the only medical treatment recognized by the medical community as a complete and permanent cure for morbid obesity and its complications. The choice of surgical modality is also based more on the experience of the physician or the requirements of people with obesity, rather than on scientific data. In this issue, a thorough comparison of the nutritional deficiencies caused by the three most commonly used surgical modalities is needed.

Objectives

We aimed to use the network meta-analysis to compare the nutritional deficiencies caused by the three most common BS procedures in many subjects who underwent BS to help physicians determine the best BS surgical approach to apply to their clinical people with obesity.

Setting

A systematic review and network meta-analysis of world literature.

Methods

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, systematically reviewed the literature, and conducted a network meta-analysis using R Studio.

Results

For the four vitamins calcium, vitamin B12, iron and vitamin D, the micronutrient deficiency caused by RYGB is the most serious.

Conclusions

RYGB causes slightly higher nutritional deficiencies in Bariatric surgery, but RYGB remains the most commonly used modality for Bariatric surgery.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022351956, identifier: CRD42022351956.

Network Meta-Analysis of Trials Testing If Home Exercise Programs Informed by Wearables Measuring Activity Improve Peripheral Artery Disease Related Walking Impairment

Background: This study aimed to investigate whether home exercise programs informed by wearable activity monitors improved walking ability of patients with peripheral artery disease (PAD). Methods: A systematic literature search was performed to identify randomised controlled trials (RCT) testing home exercise that were or were not informed by wearable activity monitors. The primary outcome was the change in walking distance measured by a six-minute walking test or treadmill test over the course of the trial. Network meta-analysis (NMA) was performed using the gemtc R statistical package. The risk of bias was assessed using Cochrane tool for assessing risk of bias in RCTs (RoB 2.0). Results: A total of 14 RCTs involving 1544 participants were included. Nine trials used wearable activity monitors to inform the home exercise program tested, while five trials did not use wearable activity monitors to inform the home exercise program tested. Overall quality assessment showed 12 trials to be at low risk of bias and two trials at high risk of bias. Home exercise programs informed by wearable activity monitors significantly improved walking distance compared to non-exercise controls (Mean difference, MD: 32.8 m [95% credible interval, CrI: 6.1, 71.0]) but not compared to home exercise programs not informed by wearable activity monitors (MD: 4.7 m [95% CrI: -38.5, 55.4]). Conclusions: Home exercise informed by wearable activity monitors improve walking ability of patients with PAD. It is, however, unclear if activity monitoring informed exercise programs are more effective than exercise programs not using activity monitors.

Current Management of Peripheral Artery Disease: Focus on Pharmacotherapy

Peripheral artery disease (PAD) is the occlusion or narrowing of the arteries supplying the lower extremities. Peripheral artery disease has been estimated to affect approximately 240 million people worldwide, approximately 70% of whom are within low- or middle-income countries. Due to the ageing population and diabetes epidemic, the prevalence of PAD is rapidly rising. The symptoms of PAD are heterogeneous and thus a high index of suspicion is needed to prevent delays in diagnosis and treatment. Measurement of ankle brachial pressure index or arterial duplex ultrasound are traditionally used to diagnose PAD. Patients with PAD have a high risk of major adverse cardiovascular events. Early diagnosis and implementation of secondary cardiovascular prevention is therefore critical. This includes therapies to reduce low-density lipoprotein cholesterol, such as statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, blood-pressure reducing medications and anti-thrombotic drugs. Treatments to facilitate smoking cessation and control blood sugar if relevant and an exercise programme are also critical in reducing cardiovascular risk. Currently, these treatments are not well implemented. This review summarises the clinical presentation, risk factors and medical management of PAD. Global efforts are needed to reduce the burden from the growing PAD epidemic by implementing best practices and improving outcomes through further research.

Update on the pathophysiology and medical treatment of peripheral artery disease

Approximately 6% of adults worldwide have atherosclerosis and thrombosis of the lower limb arteries (peripheral artery disease (PAD)) and the prevalence is rising. PAD causes leg pain, impaired health-related quality of life, immobility, tissue loss and a high risk of major adverse events, including myocardial infarction, stroke, revascularization, amputation and death. In this Review, I describe the pathophysiology, presentation, outcome, preclinical research and medical management of PAD. Established treatments for PAD include antithrombotic drugs, such as aspirin and clopidogrel, and medications to treat dyslipidaemia, hypertension and diabetes mellitus. Randomized controlled trials have demonstrated that these treatments reduce the risk of major adverse events. The drug cilostazol, exercise therapy and revascularization are the current treatment options for the limb symptoms of PAD, but each has limitations. Novel therapies to promote collateral and new capillary growth and treat PAD-related myopathy are under investigation. Methods to improve the implementation of evidence-based medical management, novel drug therapies and rehabilitation programmes for PAD-related pain, functional impairment and ischaemic foot disease are important areas for future research.

Outcomes of endovascular treatment of patients with intermittent claudication due to femoropopliteal disease

Objective

Our objective was to evaluate the outcomes of endovascular treatment in patients with moderate and severe claudication due to femoropopliteal disease, that is, disease of the superficial femoral and popliteal arteries.

Methods

A retrospective review of all patients with moderate and severe claudication (Rutherford 2 and 3) undergoing endovascular treatment for FP disease between January 2012 and December 2017 at two university-affiliated hospitals was performed. All procedures were performed by vascular surgeons. Primary outcomes were mortality, freedom from reintervention, major adverse limb events defined as major amputations, open surgical revascularization, or progression to chronic limb-threatening ischemia (CLTI) at 30 days, 1 year, 2 years, and last follow-up. Unadjusted odds ratios were calculated to identify variables associated with adverse outcomes, and Kaplan–Meier survival curves were used to determine mortality and freedom from reintervention.

Results

Eighty-five limbs in 74 patients were identified on review. Mean age was 69.6 ± 9.8 years and 74.3% were males. At a median follow-up of 49.0 ± 25.5 months, all-cause mortality rate was 8.1% (6 patients) with 16.7% being due to cardiovascular causes. Reintervention rates were 1.2%, 16.5%, and 21.2% at 30 days, 1 year, and 2 years, respectively. Major adverse limb events occurred in 3 patients and rates were 0%, 1.2%, and 2.4% at 30 days, 1 year, and 2 years, respectively. Progression to CLTI was 0%, 1.2%, and 1.2% at 30 days, 1 year, and 2 years, respectively. Claudication had improved or resolved in 55.6% (n = 34 patients), stable in 38.9% (n = 21 patients), and worse in 5.6% (n = 3 patients) Age ≥ 70 years (OR = 4.09 (1.14–14.66), p = 0.027), TASCII A lesion (OR = 4.67 (1.14–19.17), p = 0.025), and presence of 3-vessel runoff (OR = 3.70 (1.18–11.59), p = 0.022) predicted symptoms’ improvement. TASCII A lesions were less likely to require reintervention (OR = 0.23 (0.06–0.86), p = 0.020). Reintervention within 1 year (OR = 11.67 (0.98–138.94), p = 0.017), reintervention with a stent (OR = 14.40 (1.19–173.67), p = 0.008) and more than one reintervention (OR = 39.00 (2.89–526.28), p < 0.001) predicted major adverse limb events.

Conclusions

Careful patient selection is important when planning endovascular treatment in patients with intermittent claudication and FP disease. This could result in symptomatic improvement in more than half of the patients. Adverse outcomes such as major adverse limb events, progression to CLTI, and amputations occur at low rates.

The Role of Mitochondrial Function in Peripheral Arterial Disease: Insights from Translational Studies

Recent evidence demonstrates an involvement of impaired mitochondrial function in peripheral arterial disease (PAD) development. Specific impairments have been assessed by different methodological in-vivo (near-infrared spectroscopy, ³¹P magnetic resonance spectroscopy), as well as in-vitro approaches (Western blotting of mitochondrial proteins and enzymes, assays of mitochondrial function and content). While effects differ with regard to disease severity, chronic malperfusion impacts subcellular energy homeostasis, and repeating cycles of ischemia and reperfusion contribute to PAD disease progression by increasing mitochondrial reactive oxygen species production and impairing mitochondrial function. With the leading clinical symptom of decreased walking capacity due to intermittent claudication, PAD patients suffer from a subsequent reduction of quality of life. Different treatment modalities, such as physical activity and revascularization procedures, can aid mitochondrial recovery. While the relevance of these modalities for mitochondrial functional recovery is still a matter of debate, recent research indicates the importance of revascularization procedures, with increased physical activity levels being a subordinate contributor, at least during mild stages of PAD. With an additional focus on the role of revascularization procedures on mitochondria and the identification of suitable mitochondrial markers in PAD, this review aims to critically evaluate the relevance of mitochondrial function in PAD development and progression.

Phytochemicals as Therapeutic Interventions in Peripheral Artery Disease

Peripheral artery disease (PAD) affects over 200 million people worldwide, resulting in significant morbidity and mortality, yet treatment options remain limited. Among the manifestations of PAD is a severe functional disability and decline, which is thought to be the result of different pathophysiological mechanisms including oxidative stress, skeletal muscle pathology, and reduced nitric oxide bioavailability. Thus, compounds that target these mechanisms may have a therapeutic effect on walking performance in PAD patients. Phytochemicals produced by plants have been widely studied for their potential health effects and role in various diseases including cardiovascular disease and cancer. In this review, we focus on PAD and discuss the evidence related to the clinical utility of different phytochemicals. We discuss phytochemical research in preclinical models of PAD, and we highlight the results of the available clinical trials that have assessed the effects of these compounds on PAD patient functional outcomes.

Advances in Revascularization for Peripheral Artery Disease: Revascularization in PAD

Effective revascularization of the patient with peripheral artery disease is about more than the procedure. The approach to the patient with symptom-limiting intermittent claudication or limb-threatening ischemia begins with understanding the population at risk and variation in clinical presentation. The urgency of revascularization varies significantly by presentation; from patients with intermittent claudication who should undergo structured exercise rehabilitation before revascularization (if needed) to those with acute limb ischemia, a medical emergency, who require revascularization within hours. Recent years have seen the rapid development of new tools including wires, catheters, drug-eluting technology, specialized balloons, and biomimetic stents. Open surgical bypass remains an important option for those with advanced disease. The strategy and techniques employed vary by clinical presentation, lesion location, and lesion severity. There is limited level 1 evidence to guide practice, but factors that determine technical success and anatomic durability are largely understood and incorporated into decision-making. Following revascularization, medical therapy to reduce adverse limb outcomes and a surveillance plan should be put in place. There are many hurdles to overcome to improve the efficacy of lower extremity revascularization, such as restenosis, calcification, microvascular disease, silent embolization, and tools for perfusion assessment. This review highlights the current state of revascularization in peripheral artery disease with an eye toward technologies at the cusp, which may significantly impact current practice.

Network Meta-Analysis Comparing the Outcomes of Treatments for Intermittent Claudication Tested in Randomized Controlled Trials

Background No network meta-analysis has considered the relative efficacy of cilostazol, home exercise therapy, supervised exercise therapy (SET), endovascular revascularization (ER), and ER plus SET (ER+SET) in improving maximum walking distance (MWD) over short- (<1 year), moderate- (1 to <2 years), and long-term (≥2 years) follow-up in people with intermittent claudication. Methods and Results A systematic literature search was performed to identify randomized controlled trials testing 1 or more of these 5 treatments according to Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. The primary outcome was improvement in MWD assessed by a standardized treadmill test. Secondary outcomes were adverse events and health-related quality of life. Network meta-analysis was performed using the gemtc R statistical package. The Cochrane collaborative tool was used to assess risk of bias. Forty-six trials involving 4256 patients were included. At short-term follow-up, home exercise therapy (mean difference [MD], 89.4 m; 95% credible interval [CrI], 20.9-157.7), SET (MD, 186.8 m; 95% CrI, 136.4-237.6), and ER+SET (MD, 326.3 m; 95% CrI, 222.6-430.6), but not ER (MD, 82.5 m; 95% CrI, -2.4 to 168.2) and cilostazol (MD, 71.1 m; 95% CrI, -24.6 to 167.9), significantly improved MWD (in meters) compared with controls. At moderate-term follow-up, SET (MD, 201.1; 95% CrI, 89.8-318.3) and ER+SET (MD, 368.5; 95% CrI, 195.3-546.9), but not home exercise therapy (MD, 99.4; 95% CrI, -174.0 to 374.9) or ER (MD, 84.2; 95% CrI, -35.3 to 206.4), significantly improved MWD (in meters) compared to controls. At long-term follow-up, none of the tested treatments significantly improved MWD compared to controls. Adverse events and quality of life were reported inconsistently and could not be meta-analyzed. Risk of bias was low, moderate, and high in 4, 24, and 18 trials respectively. Conclusions This network meta-analysis suggested that SET and ER+SET are effective at improving MWD over the moderate term (<2 year) but not beyond this. Durable treatments for intermittent claudication are needed.