The fate of patients with intermittent claudication in the 21st century revisited - results from the CAVASIC Study

Co-Morbidity Differences Associated With Long-Term Amputation and Repeat Revascularization Rates After Femoropopliteal Artery Intervention for Intermittent Claudication by Gender, Race, and Ethnicity

Use of peripheral vascular intervention (PVI) for intermittent claudication (IC) continues to expand, but there is uncertainty whether baseline demographics, procedural techniques and outcomes differ by gender, race, and ethnicity. This study aimed to examine amputation and revascularization rates up to 4 years after femoropopliteal (FP) PVI for IC by gender, race, and ethnicity. Patients who underwent FP PVI for IC between 2016 and 2020 from the PINC AI Healthcare Database were analyzed. The primary outcome was any index limb amputation, assessed by Kaplan-Meier estimate. Secondary outcomes included index limb major amputation, repeat revascularization, and index limb repeat revascularization. Unadjusted and adjusted hazard ratios (HRs) were estimated using Cox proportional hazard regression models. This study included 19,324 patients with IC who underwent FP PVI, with 41.2% women, 15.6% Black patients, and 4.7% Hispanic patients. Women were less likely than men to be treated with atherectomy (45.1% vs 47.8%, p = 0.0003); Black patients were more likely than White patients to receive atherectomy (50.7% vs 44.9%, p <0.001), and Hispanic patients were less likely than non-Hispanic patients to receive atherectomy (41% vs 47%, p = 0.0004). Unadjusted rates of any amputation were similar in men and women (6.4% for each group, log-rank p = 0.842), higher in Black patients than in White patients (7.8% vs 6.1%, log-rank p = 0.007), and higher in Hispanic patients than in non-Hispanic patients (8.8% vs 6.3%, log-rank p = 0.031). After adjustment for baseline characteristics, Black race was associated with higher rates of repeat revascularization (adjusted HR 1.13, 95% confidence interval 1.04 to 1.22) and any FP revascularization (adjusted HR 1.10, 95% confidence interval 1.01 to 1.20). No statistical difference in amputation rate was observed among comparison groups. Women and men with IC had similar crude and adjusted amputation and revascularization outcomes after FP PVI. Black patients had higher repeat revascularization and any FP revascularization rates than did White patients. Black and Hispanic patients had higher crude amputation rates, but these differences were attenuated by adjustment for baseline characteristics. Black patients were more likely to receive atherectomy and had higher rates of any repeat revascularization and specifically FP revascularization. Further study is necessary to determine whether these patterns are related to disease-specific issues or practice-pattern differences among different populations.

Risk factors for glioblastoma in adults in Japan: an exploratory cohort study based on the Shizuoka Kokuho Database, the Shizuoka study

PURPOSE

To elucidate the risk factors associated with the onset of glioblastoma (GBM) utilizing a comprehensive administrative claims database from a major governmental district in Japan.

METHODS

Using the Shizuoka Kokuho Database (SKDB) for the period from April 2012 to September 2021, we conducted a retrospective analysis of 1,465,353 participants, identifying GBM cases using specific Japanese disease codes in conjunction with associated treatments. Risk factors were assessed using both univariable and multivariable Cox proportional hazards models.

RESULTS

Within the cohort, 182 participants (0.012%) received a GBM diagnosis during the study period, resulting in an incidence rate of 2.1 per 100,000 person-years. The multivariable analysis revealed that older age, male sex, and peripheral vascular disease (PVD) significantly influenced the risk of GBM onset. No clear link was found between allergic conditions and GBM risk, in contrast to some previous research.

CONCLUSION

Employing a robust health insurance database, this study revealed significant associations between GBM and factors such as age, male sex, and PVD within the Japanese population. It provides key insights into GBM epidemiology and underscores the potential of health insurance databases for large-scale oncological research.

Reprint of: Early peripheral vascular interventions for claudication are associated with higher rates of late interventions and progression to chronic limb threatening ischemia

OBJECTIVE

Despite societal guidelines that peripheral vascular intervention (PVI) should not be the first-line therapy for intermittent claudication, a significant number of patients will undergo PVI for claudication within 6 months of diagnosis. The aim of the present study was to investigate the association of early PVI for claudication with subsequent interventions.

METHODS

We evaluated 100% of Medicare fee-for-service claims to identify all beneficiaries with a new diagnosis of claudication from January 1, 2015 to December 31, 2017. The primary outcome was late intervention, defined as any femoropopliteal PVI performed >6 months after the claudication diagnosis (through June 30, 2021). Kaplan-Meier curves were used to compare the cumulative incidence of late PVI for claudication patients with early (≤6 months) PVI vs those without early PVI. A hierarchical Cox proportional hazards model was used to evaluate the patient- and physician-level characteristics associated with late PVIs.

RESULTS

A total of 187,442 patients had a new diagnosis of claudication during the study period, of whom 6069 (3.2%) had undergone early PVI. After a median follow-up of 4.39 years (interquartile range, 3.62-5.17 years), 22.5% of the early PVI patients had undergone late PVI vs 3.6% of those without early PVI (P < .001). Patients treated by high use physicians of early PVI (≥2 standard deviations; physician outliers) were more likely to have received late PVI than were patients treated by standard use physician of early PVI (9.8% vs 3.9%; P < .001). Patients who had undergone early PVI (16.4% vs 7.8%) and patients treated by outlier physicians (9.7% vs 8.0%) were more likely to have developed CLTI (P < .001 for both). After adjustment, the patient factors associated with late PVI included receipt of early PVI (adjusted hazard ratio [aHR], 6.89; 95% confidence interval [CI], 6.42-7.40) and Black race (vs White; aHR, 1.19; 95% CI, 1.10-1.30). The only physician factor associated with late PVI was a majority of practice in an ambulatory surgery center or office-based laboratory, with an increasing proportion of ambulatory surgery center or office-based laboratory services associated with significantly increased rates of late PVI (quartile 4 vs quartile 1; aHR, 1.57; 95% CI, 1.41-1.75).

CONCLUSIONS

Early PVI after the diagnosis of claudication was associated with higher late PVI rates compared with early nonoperative management. High use physicians of early PVI for claudication performed more late PVIs than did their peers, especially those primarily delivering care in high reimbursement settings. The appropriateness of early PVI for claudication needs critical evaluation, as do the incentives surrounding the delivery of these interventions in ambulatory intervention suites.

Lower All-Cause Mortality Risk in Females and Males with Peripheral Artery Disease following Pain-Free Home-Based Exercise: A 7-Year Observational Study

We evaluated the sex-specific difference in response upon participation in an exercise program with respect to the risk of adverse clinical outcomes among patients with peripheral artery disease (PAD) and claudication. The records of 400 PAD patients were assessed between 2012 and 2015. Two hundred of them were addressed to a walking program prescribed at the hospital and executed at home at symptom-free walking speed (Ex), while the remaining 200 acted as a control group (Co). The number and date of deaths, all-cause hospitalizations, and amputations for a 7-year period were collected from the regional registry. At baseline, no differences were observed (M_EXn = 138; F_EXn = 62; M_COn = 149; F_COn = 51). The 7-year survival rate was significantly higher in F_EX (90%) than in M_EX (82% hazard ratio, HR: 0.542 95% CI 0.331-0.885), F_CO (45%, HR: 0.164 95% CI 0.088-0.305), and M_CO (44%; HR: 0.157 95% CI 0.096-0.256). A significantly lower rate of hospitalization (p < 0.001) and amputations (p = 0.016) was observed for the Ex group compared to the Co group, without differences by sex. In conclusion, in PAD patients, active participation in a home-based pain-free exercise program was associated with a lower rate of death and better long-term clinical outcomes, particularly among women.

Cardiac Rehabilitation and Mortality Risk Reduction in Peripheral Artery Disease at 6-Month Outcome

The management of patients with peripheral artery disease (PAD) is integrative and multidisciplinary, in which cardiac rehabilitation (CR) plays a prognostic role in terms of functional status, quality of life, and long-term impact on morbidity and mortality. We conducted a prospective cohort study on 97 patients with PAD admitted to a single tertiary referral center. Based on a prognostic index developed to stratify long-term mortality risk in PAD patients, we divided the cohort into two groups: low and low-intermediate risk group (45 cases) and high-intermediate and high risk group (52 cases). We analyzed demographics, clinical parameters, and paraclinical parameters in the two groups, as well as factors associated with cardiological reassessment prior to the established deadline of 6 months. Obesity (p = 0.048), renal dysfunction (p < 0.001), dyslipidemia (p < 0.001), tobacco use (p = 0.048), and diabetes mellitus (p < 0.001) are comorbidities with long-term prognostic value. Low-density lipoprotein cholesterol (p = 0.002), triglycerides (p = 0.032), fasting glucose (p = 0.011), peak oxygen uptake (p = 0.005), pain-free walking distance (p = 0.011), maximum walking time (p < 0.001), and maximum walking distance (p = 0.002) influence the outcome of PAD patients by being factors associated with clinical improvement at the 6-month follow-up. PAD patients benefit from enrollment in CR programs, improvement of clinical signs, lipid and carbohydrate profile, and weight loss and maintenance of blood pressure profile within normal limits, as well as increased exercise capacity being therapeutic targets.

Medial Arterial Calcification: A Significant and Independent Contributor of Peripheral Artery Disease

Over 200 million individuals worldwide are estimated to have peripheral artery disease (PAD). Although the term peripheral can refer to any outer branch of the vasculature, the focus of this review is on lower-extremity arteries. The initial sequelae of PAD often include movement-induced cramping pain in the hips and legs or loss of hair and thinning of the skin on the lower limbs. PAD progresses, sometimes rapidly, to cause nonhealing ulcers and critical limb ischemia which adversely affects mobility and muscle tone; acute limb ischemia is a medical emergency. PAD causes great pain and a high risk of amputation and ultimately puts patients at significant risk for major adverse cardiovascular events. The negative impact on patients' quality of life, as well as the medical costs incurred, are huge. Atherosclerotic plaques are one cause of PAD; however, emerging clinical data now shows that nonatherosclerotic medial arterial calcification (MAC) is an equal and distinct contributor. This ATVB In Focus article will present the recent clinical findings on the prevalence and impact of MAC in PAD, discuss the known pathways that contribute specifically to MAC in the lower extremity, and highlight gaps in knowledge and tools that limit our understanding of MAC pathogenesis.

Mortality, Cardiovascular and Limb Events in Patients With Symptomatic Lower Extremity Artery Disease and Diabetes

The aim of this study was to compare the prognosis of patients according to diabetes status, during a 1-year follow-up after hospital admission for lower extremity artery disease, in the prospective COPART (COhorte de Patients ARTériopathes) registry. Inclusion criteria were intermittent claudication, ischemic rest pain, tissue loss, or acute limb ischemia, with radiological and hemodynamic confirmation. Among 2494 patients, 1235 (49.5%) had diabetes. Incidence rates for major adverse cardiovascular events (MACE) were 18.0/100 person-years (95% confidence interval [CI], 15.4-21.0) for the diabetes group and 11.1/100 person-years (95% CI, 9.2-13.4) for the non-diabetes group. Incidence rates of all-cause mortality were 29.8/100 person-years (95% CI, 26.5-33.4) for the diabetes group and 19.7/100 person-years (95% CI, 17.2-22.7) for the non-diabetes group. Incidence rates of major limb amputation were 24.2/100 person-years (95% CI, 21.1-27.8) for the diabetes group and 11.6/100 person-years (95% CI, 9.6-14.0) for the non-diabetes group. Diabetes was associated with MACE, adjusted hazard ratio 1.60 (95% CI, 1.16-2.22), and all-cause mortality, unadjusted HR 1.49 (95% CI, 1.24-1.78). In the multivariate analysis, diabetes was no longer associated with major amputation, adjusted HR 1.15 (95% CI, .87-1.51). Patients hospitalized for LEAD with diabetes had a higher risk of MACE than those without diabetes.

Characteristics of atherosclerosis in femoropopliteal artery and its clinical relevance

Atherosclerosis is a systemic disease with different faces. Despite identical or similar pathogenetic mechanisms, atherosclerotic lesions and their clinical manifestations vary in different parts of the vascular system. Peripheral arterial disease (PAD) represents one of the most frequent clinical manifestations of atherosclerosis with predominant location in the superficial femoral artery (SFA). Morphological characteristics of atherosclerotic plaques in peripheral arteries differ from lesions in the coronary and carotid arteries. Plaques in SFA have more fibrotic components, less lipids and inflammatory cells, which makes them more stable and less prone to rupture. Factors that determine the different structure of plaques in SFA compared to coronary arteries include hemodynamic forces, vasa vasorum and calcification. Low shear stress in SFA in the adductor canal is one of the factors which determines frequent atherosclerotic lesions in this region. Lower lipid content and fewer inflammatory cells explain higher stability of SFA plaques. The specific structure of SFA plaques may require preventive and therapeutic measures, which to some extent differ from prevention of coronary atherosclerosis and may include inhibition of fibrotic proliferation in SFA plaques and calcification. Revascularization of PAD differs from procedures used in coronary arteries and requires specific technical expertise and devices.

Walking Impairment Questionnaire and Walking Tests are Reliable Indicators of Success of Treatment of Peripheral Artery Disease

The functional capacity of patients with peripheral arterial disease (PAD) represents an important indicator of patient health and quality of life. The aim of this prospective study was to investigate the validity of a walking impairment questionnaire (WIQ) compared with walking tests for the estimation of the therapeutic effect of lower limb revascularization. The study included 36 patients with PAD in whom successful percutaneous revascularization of a lower limb was performed due to disabling intermittent claudication. Before the revascularization procedure and 4-6 weeks after successful revascularization, clinical examination, ankle brachial index (ABI) measurement, 6-min walk test, treadmill test, and WIQ were performed. After revascularization, significant improvement in walking capacity was shown by both 6-min walk test and treadmill exercise test as well as with WIQ. However, the increase in ABI was borderline. Significant correlations between improvement of 6-min walk test and treadmill exercise test results and the sum of WIQ points were found. The ABI was significantly correlated with treadmill maximal walking distance only. According to our results, the WIQ correlates well with walking tests and is a reliable indicator of effective revascularization of lower limb arterial occlusions, even in patients with a nonsignificant improvement of the ABI.

Epidemiology of Peripheral Artery Disease and Polyvascular Disease

Atherosclerotic lower extremity peripheral artery disease (PAD) is increasingly recognized as an important cause of cardiovascular morbidity and mortality that affects >230 million people worldwide. Traditional cardiovascular risk factors, including advanced age, smoking, and diabetes, are strongly linked to an increase risk of PAD. Although PAD has been historically underappreciated compared with coronary artery disease and stroke, greater attention on PAD in recent years has led to important new epidemiological insights in the areas of thrombosis, inflammation, dyslipidemia, and microvascular disease. In addition, the concept of polyvascular disease, or clinically evident atherosclerosis in multiple arterial beds, is increasingly identified as a particularly malignant cardiovascular disease worthy of special clinical attention and further study. It is noteworthy that PAD may increase the risk of adverse outcomes in similar or even greater magnitude than coronary disease or stroke. In this review, we highlight important new advances in the epidemiology of PAD with a particular focus on polyvascular disease, emerging biomarkers, and differential risk pathways for PAD compared with other atherosclerotic diseases.

Use of the walking impairment questionnaire as a measure of functional assessment

Background: A significant consequence of peripheral arterial disease (PAD) is an impaired functional capacity and deteriorated quality of life. Therefore, our study aimed to investigate the usefulness of a symptom questionnaire and walk tests for the determination of the functional capacity of patients with intermittent claudication. Patients and methods: The study included 53 patients (38 males) with stable claudication distance (50-300m). A detailed history and physical examination, ankle-brachial index (ABI), treadmill exercise test, and 6-minute walk test were performed and compared to walking impairment questionnaire (WIQ). Results: Claudication distance reported from patients' history and 6-minute walk test were significantly correlated with ABI (p=0.033, p=0.044). There were no significant correlations between ABI and treadmill walk test or WIQ. Results of WIQ were significantly correlated with the history and the most of performed walk tests: treadmill initial and maximal claudication distance (p=0.004 and 0.012, respectively) and 6-minute walk test (p=0.026). 6-minute walk test was correlated with maximal claudication distance of treadmill (p=0.018), but not with an initial claudication distance. Conclusions: The validity of WIQ is comparable to walk tests and represents the useful technique for the investigation of the functional capacity of patients with PAD. A self-report based on WIQ enables a longer period of observation. It should be routinely used as a basic diagnostic tool for the estimation of the functional capacity of PAD patients with stable intermittent claudication.

Skeletal Muscle Mitochondrial Dysfunction and Oxidative Stress in Peripheral Arterial Disease: A Unifying Mechanism and Therapeutic Target

Peripheral artery disease (PAD) is caused by atherosclerosis in the lower extremities, which leads to a spectrum of life-altering symptomatology, including claudication, ischemic rest pain, and gangrene requiring limb amputation. Current treatments for PAD are focused primarily on re-establishing blood flow to the ischemic tissue, implying that blood flow is the decisive factor that determines whether or not the tissue survives. Unfortunately, failure rates of endovascular and revascularization procedures remain unacceptably high and numerous cell- and gene-based vascular therapies have failed to demonstrate efficacy in clinical trials. The low success of vascular-focused therapies implies that non-vascular tissues, such as skeletal muscle and oxidative stress, may substantially contribute to PAD pathobiology. Clues toward the importance of skeletal muscle in PAD pathobiology stem from clinical observations that muscle function is a strong predictor of mortality. Mitochondrial impairments in muscle have been documented in PAD patients, although its potential role in clinical pathology is incompletely understood. In this review, we discuss the underlying mechanisms causing mitochondrial dysfunction in ischemic skeletal muscle, including causal evidence in rodent studies, and highlight emerging mitochondrial-targeted therapies that have potential to improve PAD outcomes. Particularly, we will analyze literature data on reactive oxygen species production and potential counteracting endogenous and exogenous antioxidants.

Multiple Reinterventions for Claudication are Associated with Progression to Chronic Limb-Threatening Ischemia

BACKGROUND

Claudication has a relatively benign natural history, associated with a low risk of limb loss. However, rates of progression to chronic limb-threatening ischemia (CLTI) following lower extremity revascularization (LER) for claudication remain unclear. This study examines the long-term outcomes and risk factors associated with progression to CLTI after LER for claudication.

METHODS

A single-center retrospective review of patients undergoing LER for claudication was performed from 2013-2016. Patients were stratified based on whether they progressed to CLTI or not.

RESULTS

There were 448 patients (502 limbs) treated for claudication, and 57 (12.7%) progressed to CLTI with a mean follow up time of 3.7 ± 1.5 years. Among patients who progressed, 23 (5.1%) developed tissue loss, 34 (7.6%) developed rest pain, and 6 (1.2%) underwent major amputation. The mean time of progression to CLTI was 1.6 ± 1.5 years after index LER. Patients who progressed to CLTI were more likely to have a history of congestive heart failure and prior open revascularizations compared with those who did not progress. There was no difference in type or level of index revascularization between the two groups and no difference in perioperative complications. Patients who developed CLTI had significantly higher rates of reinterventions and a mean number of reinterventions after index LER prior to developing CLTI compared to those who did not progress. Multivariable logistic regression demonstrated that history of congestive heart failure (OR = 2.8 [1.2-6.6]), stroke (OR = 2.6 [1.1-6.1]), prior open procedure (OR = 2.8 [1.3-5.9]) and increasing number of reinterventions after index LER (OR = 2.9 [1.5-5.7]) were independently associated with disease progression to CLTI.

CONCLUSIONS

Multiple reinterventions and previous open revascularization are associated with progression to CLTI following LER for claudication. Patients with atherosclerosis in the coronary and cerebrovascular beds are also more likely to have a progression of claudication to CLTI after LER.

Abnormal ankle-brachial index (ABI) predicts primary and secondary cardiovascular risk and cancer mortality

BACKGROUND

An abnormal ankle-brachial pressure index (ABI) is a marker of the risk for increased total and cardiovascular (CV) mortality. However, it is not clear whether it is associated with an even worse prognosis in patients with previous CV events or with cancer mortality.

MATERIALS AND METHODS

Consecutive subjects undergoing ABI assessment for suspected peripheral artery disease or for stratification of CV risk in ten centers in the Veneto Region (northeast Italy), between 2011 and 2014 were enrolled. The ABI was expressed as normal ≥0.9 to ≤1.3, and abnormal <0.9 or >1.3. All-cause mortality and CV or cancer mortality and hospitalizations for CV disease were collected from administrative databases up to December 2018.

RESULTS

The study enrolled 1,177 patients. ABI was abnormal in 57.2%. Median follow-up was 61.6 months (53.4-70.1). All-cause, CV and cancer mortality were higher in patients with abnormal than normal ABI, with hazard ratios (HR) respectively 2.0 (95% CI 1.48-2.69), 1.98 (95% CI 1.24-3.17) and 1.85 (95% CI 1.09-3.15). Among subjects with abnormal ABI, the risk of overall mortality, HR 1.57 (95% CI 1.17-2.12), and CV mortality, HR 2.39 (95% CI 1.43-3.99), was higher in those with previous CV events. These latter also had a higher risk of hospitalization for myocardial infarction and stroke: HR 1.85 (95% CI 1.023.37) and 2.17 (95% CI 1.10-4.28).

CONCLUSIONS

The co-existence of abnormal ABI and a history of CV events identifies subjects at higher risk, who call for a more aggressive approach. Abnormal ABI is also a predictor of cancer mortality.

A systematic review and meta-analysis of the risk of death and patency after application of paclitaxel-coated balloons in the hemodialysis access

OBJECTIVE

The comparison between paclitaxel-coated balloon (PCB) angioplasty and plain balloon angioplasty (PBA) for hemodialysis (HD) access stenosis or occlusion has not been well investigated. The objectives of this systematic review and meta-analysis were to compare all-cause mortality, HD access primary patency, and circuit primary patency after endovascular maintenance procedures using PCB angioplasty vs PBA.

METHODS

MEDLINE, Embase, and Cochrane Databases were systematically searched to identify all the relevant studies on paclitaxel-coated devices for stenosis or thrombosis of HD access. A random effects model was applied to pool the effect measures. Dichotomous data were presented using an odds ratio (OR). Effect data were presented using pooled hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

A total of 16 studies were included in this meta-analysis, 12 randomized controlled trials and 4 cohort studies involving 1086 patients who underwent endovascular treatment for HD access stenosis or occlusion. All-cause mortality rates at 6, 12, and 24 months after intervention were similar between the PCB and PBA groups (6 months: OR, 1.06 [95% CI, 0.38-2.96; P = .907; I² = 19.2%]; 12 months: OR, 1.20 [95% CI, 0.66-2.16; P = .554; I² = 0%]; 24 months: OR, 1.43 [95% CI, 0.83-2.45; P = .195; I² = 0%]). There was a significant improvement of primary patency in the PCB group compared with the PBA group (HR, 0.47; 95% CI, 0.33-0.69; P < .001; I² = 67.3%). This benefit was consistent with the analysis of randomized controlled trials, whereas cohort studies were excluded. Further subgroup analysis of target lesions demonstrated that primary patency was significantly higher in the PCB group than in the PBA group, not only for arteriovenous fistula (HR, 0.54; 95% CI, 0.30-0.98; P = .041; I² = 76.8%) but also for central venous stenosis (HR, 0.39; 95% CI, 0.22-0.71; P = .002; I² = 0%). The PCB group was associated with higher 6-month (OR, 0.40; 95% CI, 0.27-0.59; P < .001) and 24-month lesion primary patency (OR, 0.28; 95% CI, 0.11-0.72; P = .009) than PBA and was marginally associated with 12-month lesion primary patency (OR, 0.52; 95% CI, 0.26-1.03; P = .06). Circuit primary patency analysis showed a marginal trend toward better outcome in the PCB group (HR, 0.63; 95% CI, 0.40-1.00) but no statistical significance (P = .052).

CONCLUSIONS

This systematic review and meta-analysis demonstrated that PCB angioplasty is associated with significantly improved primary patency of arteriovenous fistula and central venous stenosis for HD access maintenance, with no evidence of increasing all-cause mortality based on short-term and midterm follow-up. Further large cohort study is needed to investigate long-term mortality.

Why to evaluate the functional capacity in PAD patients?

Summary: In patients with peripheral arterial disease (PAD), the ability to perform physical exercise is an essential and most important indicator of a patient’s health and quality of life. In many cases, there exists a discrepancy between lower extremity blood flow, the extent of arterial occlusion shown by morphological investigation and functional impairment. Reversal of lower extremity arterial obstruction with revascularization does not always reverse functional impairment of diseased leg. Further, training exercise and drug treatment can improve functional performance although they are not associated with an improvement in arterial obstruction. Therefore, the determination of functional impairment and its recovery after different therapeutic procedures should be determined using objective tests. The most frequently used functional tests are treadmill exercise testing and a 6-minute walk test. The constant load test, in which results are expressed as a walked distance, does not always permit an accurate assessment of the full range of functional impairment of PAD patients. Recently, as a substitute for a constant-load test, the graded treadmill test is used. With this test, it is possible to identify those individuals with exercise limitations who are not caused only by deterioration of the blood flow of lower limbs. The 6-minute walk test is simple to perform and requires minimal equipment. However, the correlation between the 6-minute walk test and the graded treadmill test is relatively weak, indicating that peak performance on a graded treadmill may reflect different pathophysiological mechanisms of limitations. In conclusion: for the determination of limitations of mobility and quality of life in patients with PAD, objective measures of functional impairment are needed. The determination of functional capacity is related to the quality of life and is a useful tool for investigation of the success of revascularization of peripheral arteries and conservative treatment.

Paclitaxel-Coated Zilver PTX Drug-Eluting Stent Treatment Does Not Result in Increased Long-Term All-Cause Mortality Compared to Uncoated Devices

Purpose

Patient-level data from two large studies of the Zilver PTX drug-eluting stent (DES) with long-term follow-up and concurrent non-drug comparator groups were analyzed to determine whether there was an increased mortality risk due to paclitaxel.

Methods

Data from the Zilver PTX randomized controlled trial (RCT) and Zilver PTX and bare metal stent (BMS) Japan post-market surveillance studies were analyzed. Five-year follow-up is complete in both DES studies; follow-up for the BMS study was limited to 3 years and is complete. Kaplan–Meier analyses assessed mortality. A Cox proportional hazards model identified significant factors related to mortality.

Results

In the RCT, there were 336 patients treated with the DES and 143 patients treated with percutaneous transluminal angioplasty (PTA) or BMS. In Japan, there were 904 DES patients and 190 BMS patients. There was no difference in all-cause mortality for the DES compared to PTA/BMS in the RCT (19.1% DES versus 17.1% PTA/BMS through 5 years, p = 0.60) or Japan (15.8% DES versus 15.3% BMS through 3 years, p = 0.89). Cox proportional hazard models revealed that age, tissue loss, and congestive heart failure were significantly associated with mortality in the RCT, and critical limb ischemia, age, renal failure, and gender were significantly associated with mortality in Japan (all p < 0.05). Neither treatment with Zilver PTX (p = 0.46 RCT, p = 0.49 Japan) nor paclitaxel dose (p = 0.86 RCT, p = 0.07 Japan) was associated with mortality.

Conclusion

Analyses of the Zilver PTX patient-level data demonstrated no increase in long-term all-cause mortality.

Level of Evidence

Zilver PTX RCT: Level 1, randomized controlled trial; Japan PMS studies: Level 3, post-market surveillance study.

Electronic supplementary material

The online version of this article (10.1007/s00270-019-02324-4) contains supplementary material, which is available to authorized users.

Mortality After Paclitaxel-Coated Device Use in Dialysis Access: A Systematic Review and Meta-Analysis

Purpose: To report the risk of all-cause mortality in patients who underwent dialysis access treatment using paclitaxel-coated devices compared with percutaneous transluminal angioplasty (PTA) with an uncoated balloon. Materials and Methods: A systematic review and meta-analysis of randomized controlled trials were performed to investigate the mortality outcomes associated with paclitaxel-coated devices in the treatment of patients with a failing dialysis access (last search date February 28, 2019). The primary endpoint was all-cause mortality. This analysis included 8 studies comparing paclitaxel-coated balloon (PCB) angioplasty (n=327) and PTA (n=331) in the treatment of failing dialysis access. None investigated paclitaxel-coated stents. Mortality data were pooled using a random effects model. Statistical heterogeneity was evaluated with a chi-square test and the I2 statistic. Summary statistics are expressed as relative risk ratios (RR) with a 95% confidence interval (CI). Results: At the pooled mean follow-up of 13.5 months (median 12, range 6–24) all-cause mortality was similar in the PCB group (13.8%) compared with PTA (11.2%; RR 1.26, 95% CI 0.85 to 1.89, p=0.25; I2=0%). Subgroup analysis, stratified according to length of follow-up, confirmed that there were no statistically significant differences in mortality at short- and midterm follow-up [6-month (8 studies): 5.2% vs 4.8%, RR 1.24, 95% CI 0.62 to 2.47, p=0.55; 12-month (6 studies): 6.3% vs 6.0%, RR 1.06, 95% CI 0.43 to 2.63, p=0.90; and 24-month (3 studies): 19.0% vs 13.5%, RR 1.38, 95% CI 0.90 to 2.12, p=0.14). Conclusion: The analysis found no difference in short- to midterm mortality among patients treated with a drug-coated balloon compared with PTA. With proven benefit and no evidence of harm, the authors recommend ongoing use of PCB for the failing dialysis access.

Efficacy and Feasibility of Pain management and Patient Education for Physical Activity in Intermittent claudication (PrEPAID): protocol for a randomised controlled trial

Background

Physical activity (PA) improves functional capacity and quality of life and provides secondary prevention benefits in individuals with peripheral arterial disease (PAD) and intermittent claudication (IC). However, pain and patient lack of knowledge are key barriers to the uptake of, and adherence to, PA recommendations. This trial will test the efficacy and feasibility of a non-invasive pain management intervention with and without patient education to improve PA in individuals with PAD and IC.

Methods

This is a randomised, controlled assessor-blinded feasibility trial with four parallel groups. Eighty adults with PAD and IC will be randomly assigned 1:1:1:1 to Active TENS (transcutaneous electrical nerve stimulation), Placebo TENS, Active TENS + Patient education or Placebo TENS + Patient education groups. All groups will continue to receive usual care over the intervention period. Participants randomised to Active TENS will receive a TENS device (preset at 120 Hz, 200 μs) and will be instructed to use the device daily at home or elsewhere for 6 weeks with a patient-determined intensity of “strong but comfortable”. Placebo TENS group participants will receive the same model of TENS device and instructions for use as those in the active group, except that the stimulation dose will be safely altered to produce non-therapeutic, ineffective stimulation. Participants randomised to patient education will receive a one-off 3-h workshop of structured group education (four to five persons in each group) and three sets of twice-weekly phone calls. Efficacy outcomes will be assessed at baseline, after 6 weeks of intervention and at 3 months follow-up. Absolute claudication distance using the Gardner treadmill protocol will be assessed as the primary outcome. Secondary outcomes will assess initial claudication distance, daily PA and patient-reported outcomes including quality of life, pain self-efficacy, depression, disease perception and walking impairment pain intensity and quality. Feasibility outcomes will assess rates of recruitment, retention and adherence. Focus groups with participants at the end of the trial will explore the acceptability of the interventions.

Discussion

This trial will determine the efficacy and feasibility of using a low-cost, CE-marked non-invasive pain management modality delivered with or without a patient-centred education intervention to improve PA in individuals with PAD and IC.

Trial registration

ClinicalTrials.gov, NCT03204825. Registered on 2 July 2017.

Electronic supplementary material

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Cardiac biomarkers but not measures of vascular atherosclerosis predict mortality in patients with peripheral artery disease

BACKGROUND

Peripheral artery disease (PAD) becomes more prevalent with advancing age and is associated with elevated risk of cardiovascular events and shortened life expectancy. We investigated the prognostic performance of cardiac and vascular biomarkers in a cohort of PAD patients.

METHODS

A total of 95 PAD patients were enrolled (mean age 68 years, range 47 to 86 years, 73 males). Carotid intima-media thickness (cIMT), ankle brachial index (ABI), high sensitive cardiac troponin T, and N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) were measured.

RESULTS

During a median follow-up time of 9.5 years, 44 patients died and 51 patients survived. Upon Kaplan-Meier survival analysis hs-TnT (P < .001) or NT-proBNP levels (P < .001) above the median but not cIMT above the median (P = .488) or ABI below the median (P < .436)were associated with reduced survival rate. Upon univariate cox regression and after adjustment for age, gender, prior cerebral artery disease, and diabetes mellitus only the association between hs-cTnT and mortality remained significant (HR 1.93, 95% CI 1.33-2.79, P < .001). In receiver operating curve analysis hs-cTnT (area under the curve [AUC]: 0.77, 95% CI: 0.67-0.87, P < .001) NT-proBNP (AUC: 0.74, 95% CI: 0.64-0.84, P < .001) as well as hs-cTnT, and NT-proBNP combined (AUC: 0.79, 95% CI: 0.69-0.88, P < .001) were superior to cIMT (AUC: 0.64, 95%, CI: 0.53-0.76, P = .022) and ABI (AUC: 0.57, 95% CI: 0.44-0.68, P = .313) in discriminating risk for mortality.

CONCLUSION

hs-cTnT and NT-proBNP should be taken into account for prognosis of patients with PAD.

Major adverse limb events and major adverse cardiac events after contemporary lower extremity bypass and infrainguinal endovascular intervention in patients with claudication

OBJECTIVE

Major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs) at 30 days provide standardized metrics for comparison and have been adopted by the Society for Vascular Surgery's objective performance goals for critical limb ischemia. However, MALEs and MACEs have not been widely adopted within the claudication population, and the comparative outcomes after lower extremity bypass (LEB) and infrainguinal endovascular intervention (IEI) remain unclear. The purpose of this study was to compare MALEs and MACEs after LEB and IEI in a contemporary national cohort and to determine predictors of MALEs and MACEs after revascularization for claudication.

METHODS

A national data set of LEB and IEI performed for claudication was obtained using National Surgical Quality Improvement Program vascular targeted Participant Use Data Files from 2011 to 2014. Patients were stratified by LEB vs IEI and compared by appropriate univariate analysis. The primary outcomes were MALE (defined as untreated loss of patency, reintervention on the index arterial segment, or amputation of the index limb) and MACE (defined as stroke, myocardial infarction, or death). Multivariable logistic regression was used to identify predictors of MALEs and MACEs.

RESULTS

A total of 3925 infrainguinal revascularization procedures (2155 LEB and 1770 IEI) were performed for claudication. There was no difference in 30-day MALEs between LEB and IEI (4.0% vs 3.2%; P = .17). On multivariable logistic regression, predictors of 30-day MALEs included tibial revascularization (odds ratio [OR], 2.2; P < .0001) and prior LEB on the same arterial segment (OR, 1.8; P = .004). LEB had significantly higher 30-day MACEs (2.0% vs 1.0%; P = .01) but similar mortality (0.5% vs 0.4%; P = .6). Predictors of MACEs included LEB vs IEI (OR, 2.1; P = .01), chronic obstructive pulmonary disease (OR, 2.2; P = .01), dialysis dependence (OR, 4.4; P = .003), and diabetes (OR, 1.9; P = .02).

CONCLUSIONS

In this large national cohort, LEB and IEI for claudication are associated with similar 30-day MALEs. Tibial revascularization and revascularization after prior failed bypass predict MALEs in claudicants and should therefore be undertaken with caution. LEB was associated with more 30-day MACEs but comparable 30-day mortality compared with IEI. Patients with end-stage renal disease, chronic obstructive pulmonary disease, and diabetes are at high risk for MACEs. The risk of 30-day MACEs after LEB should be weighed against the longer term outcomes of LEB vs IEI and conservative management, particularly in these higher risk patients. This analysis helps define contemporary 30-day outcomes after infrainguinal revascularization performed for claudication and serves as a baseline with which the short-term outcomes of future treatments can be compared.

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.