The prevalence of intermittent claudication. Sex-related differences have been eliminated

Validation of the Lithuanian Version of the Walking Impairment Questionnaire in Patients with Peripheral Arterial Disease

Background and Objectives: The Walking Impairment Questionnaire (WIQ) is a short and simple tool to measure walking impairment for patients with peripheral arterial disease requiring no special equipment or trained staff. The aim of this study was to assess the validity and reliability of the culturally adapted Lithuanian WIQ version in patients with intermittent claudication. Materials and Methods: In total, 40 patients with intermittent claudication and ankle-brachial index < 0.90 participated in this study. Reliability and internal consistency of the questionnaire were assessed by the intra-class correlation coefficient (ICC) and Cronbach's alpha (α), respectively. Validity was determined by correlations between the WIQ scores and a subjective test (Quality of Life 5 Dimension Questionnaire 3 Level Version (EQ-5D-3L)) and objective tests (6 min walk test (6MWT), treadmill test, and ankle-brachial index). Results: The test-retest reliability was assessed as excellent with an intraclass correlation coefficient of 0.90. The values of Cronbach's alpha were 0.957 (I time) and 0.948 (II time) and indicated an excellent internal consistency. Statistically significant Spearman correlations were detected between the WIQ and walking distances on the 6MWT (rho 0.514, p < 0.001) and treadmill test (rho 0.515, p < 0.001). Higher WIQ scores were associated with longer walking distances and duration. Moderate negative and low negative correlations were found between the WIQ and EQ-5D-3L scores. Conclusions: The Lithuanian version of culturally adapted WIQ demonstrates reliability and validity for patients with intermittent claudication, supported by two different walking tests showing statistically significant moderate Spearman correlations.

Sex as a Key Determinant of Peripheral Artery Disease – Epidemiology, Differential Outcomes, and Proposed Biological Mechanisms

Atherosclerotic peripheral artery disease (PAD) is associated with functional limitations and an increased risk of poor cardiovascular outcomes. Although men are traditionally viewed at higher risk of PAD than women, the true prevalence and incidence is inconsistent among available reports. Some of this variability is due to differences in PAD-related symptoms among women as well as sex-based differences in diagnostic tests, such as the ankle-brachial index, and it is critical for future epidemiologic studies to account for these differences. Generally, women with PAD experience greater functional impairment and decline then men and are less likely to receive guideline-directed medical therapy. In some settings, women are also more likely to present at later stages of disease and more often undergo lower limb amputation than men. Animal data exploring the biological underpinnings of these sex differences are limited, but several mechanisms have been postulated, including differential plaque morphology, alterations in the immune response, and hormonal variation and protection. Epidemiologic data suggest a link between inflammation and PAD and also reveal sex differences in lipid profiles associated with risk of PAD. In this review, we discuss available data on sex differences in PAD with additional focus on potential biological explanations for these differences. We also emphasize important knowledge gaps in this area, including under-representation of women in PAD clinical trials, to help guide future investigations and eliminate sex disparities in PAD.

Patient and clinician experiences and opinions of the use of a novel home use medical device in the treatment of peripheral vascular disease - a qualitative study

BACKGROUND

Peripheral vascular diseases have a significant impact on functional quality of life. Previous research has demonstrated the complex, limiting and costly economic implications of these conditions such as lower limb ulceration chronicity and ischaemic amputation. These complex, limb and life threatening conditions demand the development of novel interventions with objective research as part of that development. Hence, a novel intermittent negative pressure medical device in the form of a wearable boot (FlowOx™) was developed. As part of the development process, this study aimed to explore patient and clinician opinions of the boot.

METHODS

A qualitative approach was used to collect patient and clinician experiences in Norway. An advisory group informed the semi-structured questions used in seven patient interviews and one clinician focus group (n = 5). The data were recorded digitally and transcribed verbatim. Patient and clinician data were analysed as distinct groups using a thematic process.

RESULTS

Data analysis resulted in five themes from the patients which gave insight into; the impact of the disease process; practicalities of using the boot, positive experiences of use; perceived outcomes; reflecting on use. Six themes were created from the clinicians. These gave insight into; ideal outcomes and how to measure them; ways to potentially use the boot; using research in healthcare; positives of the device; observed effects and next steps; potential improvements to the device.

CONCLUSION

This study provides insight into the experiences and opinions of FlowOx™. Patients and clinicians were positive about the device due to its ease of use. Those patients with peripheral arterial disease experienced significantly more benefit, especially for ischaemic ulceration than those with a chronic venous condition. Clinicians placed value on the patient reported outcomes in the treatment decision-making process. This preliminary study into experiences of FlowOx™ use provides valuable feedback that will inform design modification and ongoing research into implementation points and prospective user groups. FlowOx™ demonstrates potential as a conservative therapy offering users a convenient, home use, self-care management solution for improving symptomatic peripheral arterial disease and quality of life.

Ultrasound therapy for treatment of lower extremity intermittent claudication

BACKGROUND

While often thought of as a diagnostic tool, ultrasound (US) can also potentially be used as a therapeutic modality. US applies mechanical stress on endothelial cells and induces nitric oxide synthase, which regulates the secretion of nitric oxide, a potent vasodilator. In animal ischemic models, US has been shown to improve hindlimb, myocardial, and cerebral perfusion. We performed a pilot trial of US therapy in the lower extremities of human subjects with intermittent claudication.

METHODS

10 subjects (5 male, 5 female, mean age 69.7 ± 10.3) with intermittent claudication were recruited. Both legs were placed in a specially designed boot with a water interface between US transducers and the legs. Subjects underwent pulsed US therapy at 250 kHz frequency for 30 min for three treatments a week for six weeks. Pre and post treatment ankle:brachial index (ABI), 6-min walk (6 MW), Walking Impairment Questionnaire (WIQ), and Short Form 36 (SF36) were performed. Pre and post-treatment results were compared with paired t-test.

RESULTS

Six minute walking distance at baseline was 352 ± 70 m, after one treatment session 353 ± 70 m (p = 0.99), and at completion 372 ± 71 m (p = 0.015). There was a trend toward improved ABI after 6 weeks of treatment (0.53 ± 0.17 vs 0.64 ± 0.12, p = 0.083). After six weeks, significant improvements were noted in overall WIQ score (2.00 ± 1.48 vs 2.63 ± 1.38, p = 0.0001), WIQ (distance) 2.07 ± 1.54 vs 2.73 ± 1.42 (p = 0.036), and WIQ (stair) 2.00 ± 1.67 vs 2.62 ± 1.24, p = 0.034, with a trend in WIQ (speed), 1.89 ± 1.26 vs 2.46 ± 1.43, p = 0.069. In the SF-36, significant improvements were noted in the domains of physical functioning (44.0 ± 41.6 vs 50.5 ± 41.1, p = 0.009) and role limitations - physical (35.0 ± 48.3 vs 60.0 ± 49.6, p = 0.006) after six weeks.

CONCLUSIONS

Therapeutic US is a potential noninvasive treatment for intermittent claudication. Pilot study patients noted significant improvements in 6 MW and WIQ results after 6 weeks of treatment. A nonsignificant improvement in ABI was noted. Further research will be needed to clarify optimal treatment frequency and duration.

Assessment of all-cause and cardiovascular death risk in Russian men with leg pain

Aim. To study the prevalence of intermittent claudication (IC) and assess the risk of cardiovascular and all-cause death In Russian men with IC according to 30-year follow-up.

Material and methods. The study used data obtained from representative samples of men examined inMoscow andSt. Petersburg (formerly known  as Leningrad) from 1975 to 1986. Response rate was 75%. The examination of men (n=10953) aged 35-70 years (mean age 48,8±6,6 years) was carried out according to a single protocol, which included a standard survey, biochemical profile test, measurement of blood pressure (BP) and heart rate, anthropometry and 12-lead electrocardiography. To determine IC, the original Rose questionnaire was used, according to which four categories of pain were identified. The first is the absence of pain (P0); the second — mixed pain, including not associated with exercise (P1); the third — atypical pain in calf muscles lasting >10 minutes of rest (P2); the fourth — typical IC (P3). The median follow-up was 21,9 years. In total, 7,893 people died, including 4220 people due to cardiovascular diseases (CVD). The KaplanMeier curves was used to assess the associations between IC categories and survival. The risk of death, including due to CVD, was assessed using Cox proportional hazard models.

Results. There were 38,8% of men with leg pain. The prevalence of IC in the studied sample was 1,0%, increasing with age from 0,4 to 2,3% in the older age group. As expected, individuals without leg pain live the longest. The years of life lost in persons with IC was 12. This parameter for cardiovascular deaths was 22,4 years. The contribution to survival not only of IC (P3), but also of atypical pain (P2) remains significant regardless of age. Moreover, the results of multivariate analysis showed that the contribution to mortality of P3 and P2 does not depend on increased blood pressure, smoking, ischemic and other electrocardiographic abnormalities, a history of myocardial infarction, which indicates the common etiology of lower limb and heart artery diseases. Similar data were obtained regarding cardiovascular mortality, however, the contribution of CI is more significant.

Conclusion. IC In Russian men aged 35-70 years is an independent predictor of all-cause and cardiovascular death.

Race and socioeconomic differences associated with endovascular peripheral vascular interventions for newly diagnosed claudication

BACKGROUND

Despite guidelines cautioning against the use of endovascular peripheral vascular interventions (PVI) for claudication, more than 1.3 million PVI procedures are performed annually in the United States. We aimed to describe national rates of PVI for claudication, and identify patient and county-level risk factors associated with a high rate of PVI.

METHODS

We used the Medicare claims database to identify all Medicare beneficiaries with a new diagnosis of claudication between January 2015 and June 2017. A hierarchical logistic regression model accounting for patient age, sex, comorbidities; county region and setting; and a patient race-county median income interaction was used to assess the associations of race and income with a high PVI rate.

RESULTS

We identified 1,201,234 patients with a new diagnosis of claudication for analysis. Of these, 15,227 (1.27%) underwent a PVI. Based on hierarchical logistic regression accounting for patient and county-level factors, black patients residing in low-income counties had a significantly higher odds of undergoing PVI than their white counterparts (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.20-1.40), whereas the odds of PVI for black versus white patients was similar in high-income counties (OR, 1.06; 95% CI, 0.99-1.14). PVI rates were higher for low versus high-income counties in both the black (OR, 1.46; 95% CI, 1.31-1.64) and white (OR, 1.19; 95% CI, 1.12-1.27) groups. There were no significant associations of Hispanic, Asian, North American native, or other races with PVI in either low- or high-income counties after risk adjustment (all P ≥ .09).

CONCLUSIONS

In the Medicare population, the mean rate of PVI of 12.7 per 1000 claudication patients varies significantly based on race and income. Our data suggest there are racial and socioeconomic differences in the treatment of claudication across the United States.

Drug-Eluting Stent Shows Similar Patency Results as Prosthetic Bypass in Patients with Femoropopliteal Occlusion in a Randomized Trial

BACKGROUND

Claudication and critical limb threatening ischemia are significant causes of mortality in the elderly. The gold standard of superficial femoral artery (SFA) revascularization is thus far considered to be the femoropopliteal bypass. The aim of this study was to compare mid-term patency between drug-eluting stents (DESs) and prosthetic bypass grafts (BSX). Studies have reported comparable results for both the methods.

METHODS

Forty-six patients with claudication or rest pain due to a 5-25 cm SFA occlusion were randomized between DES and BSX groups. The follow-up period was 24 months, and the primary outcome measure was overall patency. Secondary outcome measures were primary and primary assisted patency, change in ankle-brachial index (ABI), and amputation-free survival.

RESULTS

Forty-one patients were eventually analyzed. Six-month secondary patency was 91% (DES) versus 83% (BSX) (P = 0.450). The corresponding numbers at 12 months in the DES and BSX groups were 74% and 80% (P = 0.750), respectively. At 24 months, the respective numbers were 56% and 71% (P = 0.830). There were no statistically significant differences in primary or assisted primary patency at 1, 6, or 12 months.

CONCLUSION

There were no demonstrable differences in patency rates or clinical outcomes such as ABI or major amputations between DES and BSX. Although underpowered, the results suggest noninferiority of the DES compared with prosthetic bypass surgery.

TRIAL REGISTRATION

The trial was preregistered at ClinicalTrials.org (NCT01450722).

The association between smoking and the prevalence of intermittent claudication

The objective of this study was to investigate the association between smoking and the prevalence of intermittent claudication (IC). Between 1995 and 1997, all residents aged 20 years or older in Nord-Trøndelag County, Norway, were invited to take part in the Nord-Trøndelag Health Study (Helseundersøkelsen i Nord-Trøndelag: HUNT 2). A total of 19 748 participants aged 40-69 years attended. Responses to 12 questions on IC (including a Norwegian translation of the Edinburgh Claudication Questionnaire) had been previously tested against the ankle-brachial pressure index (ABPI < 0.9), and an algorithm of the best test properties was used to identify people with IC. Using logistic regression analysis we computed age-adjusted prevalence odds ratios (OR) for the association between smoking and IC. Both current (ORmen = 3.8, confidence interval (CI) 2.1-6.7, ORwomen = 2.2, CI 1.4-3.4) and former smokers (ORmen = 1.7, CI 0.9-3.2, ORwomen = 1.7, CI 1.1-2.7) had a higher prevalence of IC compared with those who had never smoked, and individuals who had stopped smoking more than 20 years previously had a substantially lower prevalence of IC (ORmen = 0.2, CI 0.1-0.5, ORwomen = 0.4, CI 0.2-0.8) than current smokers. We found no association between passive smoking and IC in either men or women. Current and previous smoking habits were positively associated with the prevalence of IC, and smoking cessation was negatively associated in men and women. Passive smoking was not associated with IC in this study.

The Norwegian Stroke in the Young Study (NOR-SYS): rationale and design

BACKGROUND

Ischemic stroke in young adults is a major health problem being associated with a higher vascular morbidity and mortality compared to controls, and a stroke recurrence rate of 25% during the first decade. The assumed cause of infarction and the detected risk factors determine the early- and long-term treatment. However, for many patients the cause of stroke remains unknown. Risk factor profile and etiology differ in young and elderly ischemic stroke patients, and atherosclerosis is the determined underlying condition in 10 to 15%. However, subclinical atherosclerosis is probably more prevalent and may go unrecognized.

METHODS/DESIGN

NOR-SYS is a prospective long-term research program. Standardized methods are used for anamnestic, clinical, laboratory, imaging, and ultrasound data collection in ischemic stroke patients aged ≤60 years, their partners and joint adult offspring. The ultrasound protocol includes the assessment of intracranial, carotid and femoral arteries, abdominal aorta, and the estimation of VAT. To date, the study is a single centre study with approximately 400 patients, 250 partners and 350 adult offspring expected to be recruited at our site.

DISCUSSION

NOR-SYS aims to increase our knowledge about heredity and the development of arterial vascular disease in young patients with ischemic stroke and their families. Moreover, optimization of diagnostics, prophylaxis and early intervention are major targets with the intention to reduce stroke recurrence and other clinical arterial events, physical disability, cognitive impairment and death.

Interobserver variability of ankle–brachial index measurements at rest and post exercise in patients with intermittent claudication

Abstract

The ankle–brachial index (ABI) post exercise is claimed to play a complementary role in the diagnosis or exclusion of intermittent claudication (IC). The interobserver variability of ABI measurements at rest and post exercise in patients with typical symptoms of IC is the subject of this study with emphasis on ABI post exercise. ABI at rest and post exercise were measured in both legs of 20 patients with typical symptoms of IC. After 15 minutes of rest these measurements were repeated by another observer. Analysis according to Bland–Altman was performed on 40 paired leg measurements at rest and 40 paired leg measurements post exercise. The average ABI at rest for the first observer was 0.84 (standard deviation ±0.18) and for the second was 0.84 (±0.17). Post-exercise averages were 0.73 (±0.25) and 0.74 (±0.27), respectively. The standard deviation of the ABI difference between observers was 0.08 at rest and 0.15 post exercise. The interobserver variability of the ABI was 10% at rest and 21% post exercise. The interobserver variability post exercise is an important given when rules are defined about how the ABI post exercise translates into a more reliable and objective diagnosis of IC.

The association between diabetes mellitus and the prevalence of intermittent claudication: the HUNT study

The objective of this study was to investigate the association between diabetes mellitus (DM) and the prevalence of intermittent claudication (IC). Between 1995 and 1997, all residents aged 20 years or older in Nord-Trøndelag County, Norway were mailed an invitation to participate in a health survey (HUNT 2). A total of 19,712 participants aged 40-69 years old completed and returned the questionnaire included with the invitation. They also attended an examination where brachial blood pressure was measured and non-fasting venous blood was collected. The venous blood sample was subsequently analysed for concentrations of blood lipids. Responses to 12 questions on IC were previously tested against ankle blood pressure measurements (ABPI < 0.9) and the algorithm with the best test properties was used to identify individuals with IC. Participants reported a history of DM by simple questions in the questionnaire. Logistic regression analysis was then used to compute age-adjusted prevalence odds ratios for the association between exposure variables and the prevalence of IC. Potential confounding by smoking, blood lipids and brachial blood pressure was investigated in multivariate analyses. For both sexes IC was more common in individuals with DM (OR(women) = 3.8, CI, 1.9-7.6; OR(men) = 2.8, CI, 1.4-5.8) compared to participants without DM. Adjustment for smoking, blood lipids and brachial blood pressure did not substantially change these results. In conclusion, the prevalence of IC was more than three times higher in patients with DM compared to non-diabetic participants.

Serum Lipids and Anthropometric Factors Related to the Prevalence of Intermittent Claudication

PURPOSE

To study serum lipids, body mass index (BMI), and body shape in relation to intermittent claudication (IC) in 19,748 men and women 40-69 years of age.

METHOD

All residents (1995-1997) in Nord-Trøndelag County, Norway, were invited to attend the cross sectional study and received a Norwegian translation of the WHO/Rose questionnaire on intermittent claudication and the Edinburgh claudication questionnaire. Blood lipids and anthropometric data were measured at a consecutive examination. Odds ratios (OR) were estimated for associations with IC by multiple regression analysis.

RESULTS

The ratio of total cholesterol to HDL cholesterol (TC/HDL cholesterol) (P trend(men)=.023; P trend(women)<.001) and triglycerides (P trend(men)=.029; P trend(women)=.002) were positively associated with the prevalence of IC. HDL cholesterol was negatively (P trend(men)=.131; P trend(women)<.001) associated, whereas BMI (P trend(women)=.032), waist circumference (P trend(women)=.021), and hip circumference (P trend(women)=.020) were positively associated with IC in women, but not in men. Adjustment for smoking, diabetes, and systolic or diastolic blood pressure did not change the results.

CONCLUSION

TC/HDL cholesterol and triglycerides were positively, and HDL cholesterol negatively associated with IC in both genders. In women, but not in men, BMI, waist and hip circumference were positively associated with IC.

Successful Treatment of Buerger's Disease with Intramedullary K-wire: The Results of the First 11 Extremities

OBJECTIVE

This study describes a new technique for treatment of Buerger's disease, developed to stimulate angiogenesis, using a Kirschner wire placed in the medullary canal of the tibia. The aim of the study was to evaluate clinical and radiological effects of this technique in patients where medical and surgical therapy had failed.

MATERIAL AND METHODS

Eleven extremities (six patients) with Buerger's disease were treated with the intramedullary Kirschner wire technique. Inclusion criteria were chronic critical ischemia, Rutherford Grade II or III, with major arterial occlusion shown by Doppler examination and angiography; failure to respond to non-surgical and surgical treatment; and the need for strong analgesics.

RESULTS

The mean follow-up time was 19 months (range, 13-25 months). Satisfactory remission in each patient was obtained within 6 weeks of intervention. A significant improvement in clinical manifestations including reduced rest pain and increased claudication distance was observed. Foot ulcers completely healed after Kirschner wire intervention.

CONCLUSION

Despite short-term follow-up and small patient series, the intramedullary Kirschner wire technique can be expected to achieve relief of pain and a decrease in major amputations in patients with Buerger's disease in whom medical and surgical therapy had failed. However, comparative studies with longer follow-up should be done to confirm the benefits of this new treatment.