Women and Peripheral Arterial Disease: A Review of Sex Differences in Epidemiology, Clinical Manifestations, and Outcomes

Overview and comparison of contemporary Society for Vascular Surgery, American Heart Association/American College of Cardiology, and European Society for Vascular Surgery guidelines for the management of patients with intermittent claudication

Intermittent claudication (IC) is a phenotype of peripheral artery disease that is characterized by pain in the lower extremity muscles during activity that is relieved by rest. Medical management, risk factor control, smoking cessation, and exercise therapy have historically been the mainstays of treatment for IC, but advances in endovascular technology have led to increasing use of peripheral vascular interventions in this patient population. There are meaningful differences in published society guidelines and appropriate use criteria relevant to the management of IC, especially regarding indications for peripheral vascular interventions. The current review aims to highlight similarities and differences between major society recommendations for the management of IC, and to discuss practice trends, disparities, and evidence gaps in the use of peripheral vascular interventions for IC in the context of existing guidelines.

In-patient characteristics of peripheral artery disease in Germany

Background: Peripheral artery disease (PAD) frequently leads to hospital admission. Sex related differences in in-patient care are a current matter of debate. Patients and methods: Data were provided from the German national in-patient sample provided by the Federal Bureau of Statistics (DESTATIS). Trends on risk profiles, therapeutic procedures, and outcomes were evaluated from 2014 until 2019 stratified by sex and PAD severity. Results: Two-thirds of an annual >191,000 PAD in-patient cases applied to male sex. Chronic limb-threatening ischemia (CLTI) was recorded in 49.6% of male and 55.2% of female cases (2019). CLTI was as a major risk factor of in-hospital amputation (OR 229) and death (OR 10.5), whereas endovascular revascularisation (EVR) with drug-coated devices were associated with decreased risk of in-hospital amputation (OR 0.52; all p<0.001). EVR applied in 47% of CLTI cases compared to 71% in intermittent claudication (IC) irrespective of sex. In-hospital mortality was 4.3% in male vs. 4.8% in female CLTI cases, minor amputations 18.4% vs. 10.9%, and major amputation 7.5% vs. 6.0%, respectively (data 2019; all p<0.001). After adjustment, female sex was associated with lower risk of amputation (OR 0.63) and death (OR 0.96) during in-patient stay. Conclusions: Male PAD patients were twice as likely to be admitted for in-patient treatment despite equal PAD prevalence in the general population. Among in-patient cases, supply with invasive therapy did not relevantly differ by sex, however is strongly reduced in CLTI. CLTI is a major risk factor of adverse short-term outcomes, whereas female sex was associated with lower risk of in-patient amputation and/or death.

A systematic review of disparities in the medical management of atherosclerotic cardiovascular disease in females

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death in the United States and worldwide. Medical management of known modifiable risk factors, such as dyslipidemia, hypertension, and diabetes, is a key aspect to its treatment. Unfortunately, there are substantial sex-based differences in the treatment of ASCVD that result in poor medical management and worse clinical outcomes. The objective of this systematic review was to summarize known disparities in the medical management of ASCVD in females. We included prior studies with specific sex- and sex-based analyses regarding the medical treatment of the following three major disease entities within ASCVD: cerebrovascular disease, coronary artery disease, and peripheral artery disease. A total of 43 articles met inclusion criteria. In our analysis, we found that females were less likely to receive appropriate treatment of dyslipidemia or be prescribed antithrombotic medications. However, treatment differences for diabetes and hypertension by sex were not as clearly represented in the included studies. In addition to rectifying these disparities in the medical management of ASCVD, this systematic review highlights the need to address larger issues, such as underrepresentation of females in clinical trials, decreased access to care, and underdiagnosis of ASCVD to improve overall care for females.

Contemporary Medical Management of Peripheral Arterial Disease

PURPOSE

Peripheral arterial disease (PAD) is characterized by atherosclerotic arterial occlusive disease of the lower extremities and is associated with an increased risk of major adverse cardiovascular events (MACE) in addition to disabling clinical sequelae, including intermittent claudication and chronic limb-threatening ischemia (CLTI). Given the growing burden of disease, knowledge of modern practices to prevent MACE and major adverse limb events (MALE) is essential. This review article examines evidence for medical management of PAD and its associated risk factors, as well as wound prevention and care.

METHODS

A thorough review of the literature was performed, with attention to evidence for the management of modifiable atherosclerotic risk factors, claudication symptoms, wound prevention, and wound care.

RESULTS

Contemporary management of PAD requires a multi-faceted approach to care, with medical optimization of smoking, hypertension, hyperlipidemia, and diabetes mellitus. The use of supervised exercise therapy for intermittent claudication is highlighted. The anatomic disease patterns of smoking and diabetes mellitus are discussed further, and best practices for diabetic foot ulcer prevention, including offloading footwear, are described. Quality wound care is essential in this patient population and involves strategic use of debridement, wound-healing adjuncts, and skin substitutes, when appropriate.

CONCLUSION

The objective of medical management of PAD is to reduce the risk of MACE and MALE. Atherosclerotic risk factor optimization, appropriate wound care, and management of diabetic foot ulcers, foot infections, gangrene, and chronic, non-healing wounds are critical components of PAD care. Interdisciplinary care is essential to coordinate care, leverage expertise, and improve outcomes.

Chronic Limb-Threatening Ischemia in Patients with Type 2 Diabetes: Revascularization Index as a Predictor for Primary Endovascular Intervention Outcome

Purpose

Chronic limb-threatening ischemia in patients with diabetes is associated with a high risk of adverse outcomes. The associated co-morbidities, the heterogeneity of foot presentation and the distribution of atherosclerotic lesions led to the emergence of multiple revascularization strategies and scoring systems to improve management outcomes. This study aimed to introduce a new index, the revascularization index (RI), and to assess its predictive value for the outcomes of primary endovascular intervention in patients with type 2 diabetes presenting with chronic limb-threatening ischemia.

Patients and Methods

A retrospective electronic medical records review was conducted for patients with type 2 diabetes presenting with chronic limb-threatening ischemia managed at King Abdullah University Hospital by primary endovascular interventions between January 2014 and August 2019. The RI was analyzed for its predictive value for the treatment outcomes.

Results

A total of 187 patients were included in this study, with a major lower limb amputation rate of 19.3%. The performance of the RI was excellent in predicting secondary revascularization (AUC = 0.80, 95% CI: 0.73-0.86, p-value < 0.001), good to predict major amputation (AUC = 0.76, 95% CI: 0.67-0.85, p-value = 0.047), and poor in predicting death (AUC = 0.46, 95% CI: 0.40-0.55, p-value = 0.398). RI of <1.21 was significantly associated with a higher risk of major lower limb amputation (HR = 5.8, 95% CI: 1.25-26.97, p-value < 0.025), and RI of < 1.3 was associated with a higher risk for secondary revascularization.

Conclusion

The RI can be used to predict major adverse lower limb events (MALE). It might be used as a guide for the extent of endovascular interventions for diabetic chronic limb-threatening ischemia with multi-level outflow atherosclerotic disease.

Association of sex and cardiovascular risk factors with atherosclerosis distribution pattern in lower extremity peripheral artery disease

Objective

Atherosclerosis expression varies across not only coronary, cerebrovascular, and peripheral arteries but also within the peripheral vascular tree. The underlying pathomechanisms of distinct atherosclerosis phenotypes in lower extremity peripheral artery disease (PAD) is poorly understood. We investigated the association of cardiovascular risk factors (CVRFs) and atherosclerosis distribution in a targeted approach analyzing symptomatic patients with isolated anatomic phenotypes of PAD.

Methods

In a cross-sectional analysis of consecutive patients undergoing first-time endovascular recanalization for symptomatic PAD, data of patients with isolated anatomic phenotypes of either proximal (iliac) or distal (infrageniculate) atherosclerosis segregation were extracted. We performed a multivariable logistic regression model with backward elimination to investigate the association of proximal and distal PAD with CVRFs.

Results

Of the 637 patients (29% females) with endovascular recanalization, 351 (55%) had proximal and 286 (45%) had distal atherosclerosis. Female sex [odds ratio (OR) 0.33, 95% confidence interval (CI) 0.20-0.54, p = 0.01], active smoking (OR 0.16, 95% CI 0.09-0.28, p < 0.001), and former smoking (OR 0.33, 95% CI 0.20-0.57, p < 0.001) were associated with proximal disease. Diabetes mellitus (DM) (OR 3.25, 95% CI 1.93-5.46, p < 0.001), chronic kidney disease (CKD) (OR 1.18, 95% CI 1.08-1.28, p < 0.001), and older age (OR 1.31, 95% CI 1.06-1.61, p = 0.01) were associated with distal disease.

Conclusion

Female sex, particularly in the context of smoking, is associated with clinically relevant, proximal atherosclerosis expression. Our additional findings that distal atherosclerosis expression is associated with DM, CKD, and older age suggest that PAD has at least two distinct atherosclerotic phenotypes with sex-specific and individual susceptibility to atherogenic risk factors.

Sex differences in diabetic foot ulcer severity and outcome in Belgium

BACKGROUND

Sex differences are increasingly recognized to play an important role in the epidemiology, treatment and outcomes of many diseases. This study aims to describe differences between sexes in patient characteristics, ulcer severity and outcome after 6 months in individuals with a diabetic foot ulcer (DFU).

METHODS

A total of 1,771 patients with moderate to severe DFU participated in a national prospective, multicenter cohort study. Data were collected on demographics, medical history, current DFU and outcome. For data analysis, a Generalized Estimating Equation model and an adjusted Cox proportional hazards regression were used.

RESULTS

The vast majority of patients included were male (72%). Ulcers in men were deeper, more frequently displaying probe to bone, and more frequently deeply infected. Twice as many men presented with systemic infection as women. Men demonstrated a higher prevalence of previous lower limb revascularization, while women presented more frequently with renal insufficiency. Smoking was more common in men than in women. No differences in presentation delay were observed. In the Cox regression analysis, women had a 26% higher chance of healing without major amputation as a first event (hazard ratio 1.258 (95% confidence interval 1.048-1.509)).

CONCLUSIONS

Men presented with more severe DFU than women, although no increase in presentation delay was observed. Moreover, female sex was significantly associated with a higher probability of ulcer healing as a first event. Among many possible contributing factors, a worse vascular state associated with a higher rate of (previous) smoking in men stands out.

Gender Differences in Coronary Artery Disease, Clinical Characteristics, and Angiographic Features in the Jazan Region, Saudi Arabia

BACKGROUND

Cardiovascular disease is a major cause of death worldwide. In Saudi Arabia and the gulf area, coronary artery disease (CAD) is considered a serious problem with high mortality. Previous studies identified multiple risk factors, that include hypertension, diabetes, dyslipidemia, obesity, smoking, and low physical activity, which might be related to lifestyle changes over the last few decades. Limited data about gender differences in clinical and angiographic characteristics among CAD patients in the Jazan region are available. The aim of this study is to assess potential gender differences in CAD and its clinical characteristics and angiographic features in the Jazan region.

METHODS

This retrospective chart review collected data between January 2020 and March 2021 from the follow-ups of 498 patients (100 females and 398 males) aged over 18 years at the Prince Mohammed bin Nasser Hospital in the Jazan region of Saudi Arabia. The data were collected after all patients admitted to the hospital were reviewed, and cardiac catheterization was performed.

RESULTS

Of the 498 patients with CAD, 100 (20.1%) were female and 398 (79.9%) were male. The mean age of female patients (59.44 years) was significantly higher than that of male patients (55.1 years; P=0.0002). In addition, risk factors differed significantly between genders (P=0.0210). Moreover, vessels differed significantly between genders (P=0.0002). Coronary angiogram findings showed significant correlations between gender and percutaneous coronary intervention (PCI; P=0.0001) and MEDICAL (P=0.0010). Diagnosis findings showed significant gender differences in STEMI (P<0.0010) and unstable angina (P<0.0010).

CONCLUSIONS

CAD severity did not differ by gender, but coronary angiogram findings showed significant relationships between gender, PCI, and MEDICAL treatment with CAD.

The assessment of lower extremity peripheral artery disease impact on body mass center disorders

BACKGROUND

Lower extremity peripheral artery disease is a problem of contemporary medicine and along with the ischemic heart disease it is considered to be a civilization disease. The risk of the disease increases significantly within a group of people reaching the age of 55 years and is closely related to co-occurring hazardous factors, such as diabetes, hyperlipidemia, hypertension or tobacco smoking. The first symptom reported by patients is intermittent claudication. Such symptoms may indicate that lower extremity peripheral artery disease does have an impact on posture disorders and motor skills.

METHODS

The study covered four stages. The first stage involved medical interviews to obtain information regarding anthropometry, age, motor organ surgery, concomitant diseases and the lifestyle. In the following stage the value of the ankle brachial index for both lower limbs were calculated. In case of symptomatic patients, additionally, the location of artery stenosis/aortoiliac section, was verified. The third stage involved using a dynamometric platform for determination of the body mass center position for both studied groups. In the fourth stage a treadmill walk test was used to assess the participants for intermittent claudication.

FINDINGS

Based on the obtained results, an attempt was taken to observe the relationship between the clinical characteristics of the disease and the body mass center position deviations.

INTERPRETATION

The attempt was undertaken to assess whether the measurement of body mass center position might be a diagnostic parameter to evaluate the patient's condition and thus an indication for taking a decision for surgical treatment or rehabilitation.

Burden of Peripheral Artery Disease and Its Attributable Risk Factors in 204 Countries and Territories From 1990 to 2019

Background

Data on burden of peripheral artery disease (PAD) and its attributable risk factors are valuable for policymaking. We aimed to estimate the burden and risk factors for PAD from 1990 to 2019.

Methods

We extracted the data on prevalence, incidence, death, years lived with disability (YLDs), and years of life lost (YLLs) from the Global Burden of Disease Study 2019 to measure PAD burden. Moreover, the attributable burden to PAD risk factors was also estimated.

Results

Globally, in 2019, 113,443,017 people lived with PAD and 10,504,092 new cases occurred, resulting in 74,063 deaths, 500,893 YLDs, and 1,035,487 YLLs. The absolute numbers of PAD prevalent and incident cases significantly increased between 1990 and 2019, contrasting with the decline trends in age-standardized prevalence and incidence rates. However, no statistically significant changes were detected in the global age-standardized death or YLL rates. The burden of PAD and its temporal trends varied significantly by location, gender, age group, and social-demographic status. Among all potentially modifiable risk factors, age-standardized PAD deaths worldwide were primarily attributable to high fasting plasma glucose, followed by high systolic blood pressure, tobacco, kidney dysfunction, diet high in sodium, and lead exposure.

Conclusion

PAD remained a serious public health problem worldwide. More strategies aimed at implementing cost-effective interventions and addressing modifiable risk factors should be carried out, especially in regions with high or increasing burden.

Perfusion, Stance and Plantar Pressure Asymmetries on the Human Foot in the Absence of Disease—A Pilot Study

Physiological perfusion asymmetries in the lower limb are known, although poorly understood, as are asymmetries reported in plantar pressure and stance. This preliminary study aims to explore potential relationships between perfusion and pressure variables in humans. A convenience sample of eight healthy individuals (25.25 ± 5.37 years old) of both sexes, was selected. Chosen variables were perfusion, plantar pressure, and stance. Perfusion was measured in both feet by laser Doppler flowmetry (LDF) and polarized light spectroscopy (PSp), and plantar pressure and stance obtained by a pressure plate. These were measured in baseline (Phase I) in a repeated squatting (Phase II), and in recovery (Phase III). A 95% confidence interval was adopted. Intraindividual significant perfusion asymmetries between both feet were detected by LDF in Phase I. These disappeared in Phase II and returned in Phase III. PSp did not detect any asymmetries. Plantar pressure was also asymmetric and differently distributed along both feet with no statistical significance except in the hindfoot. Significant correlations were found between BMI and mean Plantar Pressure in Phase I and Phase III, and an inverse correlation between LDF perfusion and Plantar Pressure in Phase I. These results seem to suggest an interesting direction for exploration and study of these asymmetries in the absence of disease.

Women Specific Characteristics and 1-Year Outcome Among Patients Hospitalized for Peripheral Artery Disease: A Monocentric Cohort Analysis in a Tertiary Center

Although women have lower age-standardized cardiovascular disease incidence, prevalence, and death-related rates than men, there are also reports indicating that women with cardiovascular disease receive less care, fewer investigations, and have poorer outcomes after a coronary event. The aims of this study were to compare the characteristics of men and women hospitalized for peripheral artery disease (PAD), their cardiovascular and limb outcomes, and their 1-year mortality. The study is a prospective registry collecting data about all consecutive patients hospitalized for PAD within the vascular department of the tertiary center Georges-Pompidou European Hospital (Paris, France). Patients were required to have one of three inclusion criteria: previous revascularization of the lower limb or any lower limb artery occlusion due to an atherosclerotic vascular disease or hemodynamic evidence of PAD. Exclusion criteria were patients with lower extremity arterial occlusion due to another cause. All patients were followed-up for at least 12 months after the initial hospitalization. Among the 235 patients included, there were 61 women (26%), older than men with a median age of 75.6 and 68.3 years, respectively. Main cardiovascular risk factors and comorbidities were similar for men and women except more former or current smokers [145 (83.4%) vs. 33 (54.1%)] and more history of coronary heart disease [42 (24.1%) vs. 7 (11.5%)] in men. Most patients [138 (58.8%)] had critical limb ischemia and 97 (41.3%) had claudication, with no difference for sex. After discharge, 218 patients received an antithrombotic therapy (93.2%), 195 a lipid-lowering drug (83.3%), 185 an angiotensin converting enzyme inhibitor or angiotensin-receptor blocker (78.9%), similarly between sex. At 1-year, overall mortality, major adverse cardiovascular events, major adverse limb events did not differ with 23 (13.2%), 11 (6.3%) and 32 (18.4%) in men, and 8 (13.1%), 3 (4.9%), 15 (24.6%) in women, respectively, despite the difference in age. Overall mortality, cardiovascular outcomes, limb revascularization or amputation did not differ between men and women, 1-year after hospitalization for PAD although the latter were older, less smoker and had less coronary artery disease. Due to the small size of this cohort, larger studies and future research are needed to better understand sex-specific mechanisms in the pathophysiology and natural history of PAD.

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.

Lower Limb Perfusion Asymmetries in Humans at Rest and Following Activity—A Collective View

The significance of lower limb perfusion asymmetries remains unknown in healthy individuals. Our study aims to understand how factors such as posture, sex, age, and body weight relate to perfusion. Data from studies previously published by our group, including experiments using laser Doppler flowmetry as the gold standard for perfusion measurements in baseline, (various) challenge, and recovery phases was assembled from a total of 139 healthy participants. Body position was shown to be a primary determinant of perfusion asymmetry, especially in women. Effects of sex and age were also analyzed. In a supine position, perfusion asymmetries seemed to relate negatively in the aged group of participants, where challenge and recovery seemed to follow different processes. In the upright position, young men and women have shown comparable distributions and asymmetry ratios at baseline and recovery. In the aged group, differences between sexes were observed at baseline, but again, the course of the asymmetry ratios with challenge was essentially similar in men and women. Our analysis suggests that ageing is a critical determinant in our upright study sample, as higher baseline asymmetries and longer recoveries after challenge were linked in older males with higher body mass index (BMI).

Sex-Specific Response to Combinations of Shear Stress and Substrate Stiffness by Endothelial Cells In Vitro

By using a full factorial design of experiment, the combinatorial effects of biological sex, shear stress, and substrate stiffness on human umbilical vein endothelial cell (HUVEC) spreading and Yes-associated protein 1 (YAP1) activity are able to be efficiently evaluated. Within the range of shear stress (0.5-1.5 Pa) and substrate stiffness (10-100 kPa), male HUVECs are smaller than female HUVECs. Only with sufficient mechanical stimulation do they spread to a similar size. More importantly, YAP1 nuclear localization in female HUVECs is invariant to mechanical stimulation within the range of tested conditions whereas for male HUVECs it increases nonlinearly with increasing shear stress and substrate stiffness. The sex-specific response of HUVECs to combinations of shear stress and substrate stiffness reinforces the need to include sex as a biological variable and multiple mechanical stimuli in experiments, informs the design of precision biomaterials, and offers insight for understanding cardiovascular disease sexual dimorphisms. Moreover, here it is illustrated that different complex mechanical microenvironments can lead to sex-specific phenotypes and sex invariant phenotypes in cultured endothelial cells.

Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association

Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.

Antithrombotic regimens in females with symptomatic lower extremity peripheral arterial disease: protocol for a systematic review and meta-analysis

INTRODUCTION

Patients with peripheral arterial disease (PAD) are at increased risk for systemic arterial thromboembolic events. Females represent a unique subset of patients with PAD, who differ from males in important ways: they have smaller diameter vessels, undergo lower extremity bypass less frequently and experience higher rates of graft occlusion, amputation and mortality than males. Females also trend towards higher rates of major coronary events and cardiovascular mortality. Current guidelines recommend monoantiplatelet therapy (MAPT) for secondary prevention in patients with symptomatic PAD. However, indications for more intensive antithrombotic therapy in this cohort-especially among females who are frequently under-represented in randomised controlled trials (RCTs)-remain unclear. As newer antithrombotic therapies emerge, some RCTs have demonstrated differential effects in females versus males. A systematic review is needed to quantify the rates of arterial thromboembolic and bleeding events with different antithrombotic regimens in females with symptomatic PAD.

METHODS AND ANALYSIS

We will search MEDLINE, Embase and the Cochrane Central Register of Controlled trials for published RCTs that include females with symptomatic PAD and compare full dose anticoagulation±antiplatelet therapy, dual pathway inhibition or dual antiplatelet therapy with MAPT. Title, abstract and full-text screening will be conducted in duplicate by three reviewers. Authors will be contacted to obtain sex-stratified outcomes as needed. Risk of bias will be assessed using the Cochrane Risk of Bias tool. Data will be extracted by independent reviewers and confirmed by a second reviewer. Quantitative synthesis will be conducted using Review Manager (RevMan) V.5 for applicable outcomes data. Planned subgroup analysis by PAD severity, vascular intervention and indication for antithrombotics will be conducted where data permits.

ETHICS AND DISSEMINATION

Ethics approval is waived as the study does not involve primary data collection. This review will be submitted for publication in a peer-reviewed journal and for presentation at national and international scientific meetings.

TRIAL REGISTRATION NUMBER

This protocol was registered with the PROSPERO International Prospective Register of Systematic Reviews (ID# CRD42020196933).

Risk of peripheral artery disease according to race and sex: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

Previous community-based studies have demonstrated sex and race-based disparities in the risk of cardiovascular disease. We sought to examine the association of sex and race with incident peripheral artery disease (PAD-) and critical limb ischemia (CLI-) related hospitalizations.

METHODS

In 13,451 Black and White ARIC participants without prevalent PAD at baseline (1987-89), we estimated the cumulative incidence of PAD- and CLI-related hospitalization over a median follow-up of 26 years. We quantified hazard ratios (HRs) using Cox models across four sex- and race-groups. PAD and CLI were defined by hospitalization discharge codes.

RESULTS

The cumulative incidence of PAD-related hospitalization was higher in males than females in Whites (5.1% vs. 2.7%; p<0.001) but not in Blacks (5.7% vs. 5.0%; p=0.39). The cumulative incidence of CLI-related hospitalization differed significantly by race more than sex, occurring in 3.1% Black males, 3.1% Black females, 1.4% White males, and 0.8% White females (p<0.001). After risk factor adjustment, the risk of incident PAD-related hospitalization was similar for White males vs. White females [HR 1.14, 95%CI 0.90-1.45], and slightly higher for Black males [HR 1.26, 95%CI 0.92-1.72] and Black females [HR 1.39, 95%CI 1.03-1.87] compared to White females. The adjusted risk of incident CLI-related hospitalization was similar for White males vs. White females [HR 1.15, 95%CI 0.75-1.76], and significantly higher for Black males [HR 1.96, 95%CI 1.22-3.16] and Black females [HR 2.06, 95%CI 1.31-3.24] compared to White females.

CONCLUSIONS

These data suggest that there are both sex- and race-specific patterns of PAD-related hospitalization that lead to differences in clinical disease risk and presentation.

Let's Talk About Sex-Biological Sex Is Underreported in Biomaterial Studies

Precision medicine aims to better individualize healthcare. It requires that biomaterials be designed for the physiological characteristics of a specific patient. To make this a reality, biomaterials research and development must address differences of biological sex. More specifically, biomaterials should be designed with properties optimized and appropriate for male and female patients. In analyzing research articles from seven prominent biomaterials journals, sex as a biological variable is missing from an overwhelming majority of in vitro biomaterial studies. From the survey, the reporting of the sex of primary cell cultures happened only 10.3% of the time. Contributing to this trend is that commercial vendors bias cell lines toward one sex or another by not disclosing information of cell line sex at the time of purchase; researchers do not communicate this pertinent information in published studies; and many journal policies have little to no requirements for reporting cell line characteristics. Omitting this valuable information leads to a gap in the understanding of sex-specific cell-biomaterial interactions and it creates a bias in research findings towards one sex or another. To curb this concerning trend and make precision biomaterials a reality will require the biomaterials field to "talk about sex" by reporting cell sex more broadly.

The Effect of Exercise During Pregnancy on Maternal and Offspring Vascular Outcomes: a Pilot Study

The aim of this pilot study is to obtain estimates for the change in maternal cerebrovascular (primary) and offspring vascular structure (secondary) during healthy pregnancy that includes structured exercise. Eighteen pregnant women self-assigned to a moderate-intensity aerobic exercise intervention or a control group. Maternal cerebral blood flow (CBF) at the middle cerebral artery, cerebro- and peripheral-vascular function was assessed at the end of each trimester. Offspring carotid artery intima-media thickness (IMT) was measured within 12 weeks of birth. For exploratory purposes, we performed statistical analysis to provide estimates of the change for primary and secondary outcome variables. Maternal CBF reduced (− 8 cm s⁻¹ [− 14 to − 2]) with evidence of change to cerebral autoregulation (normalised gain: 0.12 %cm s⁻¹% mmHg⁻¹mmHg/% [− 0.18 to 0.40]) during pregnancy. Offspring carotid IMT was smaller in the exercise group (− 0.04 mm [− 0.12–0.03]) compared with controls. Based upon this data, a sample size of 33 and 57 in each group is required for low-frequency normalised gain and offspring IMT, respectively. This would provide 90% power to detect statistically significant (P < 0.05) between group differences in a randomised controlled trial. CBF is reduced in pregnancy, possibly due to reduced vascular resistance and altered maternal cerebral autoregulation. Maternal exercise had negligible effects on cerebrovascular adaptation to pregnancy, but we observed lower offspring carotid artery wall thickness following maternal exercise. Our directional findings and sample size estimations should be explored in a fully powered randomised control trial.

Clinical trial registration: The trial was registered on March 14th at https://register.clinicaltrials.gov (NCT03079258). Participant enrolment began on 3rd April 2016.

Diabetes as a risk factor for incident peripheral arterial disease in women compared to men: a systematic review and meta-analysis

Aims/hypothesis

Previous meta-analyses have suggested that diabetes confers a greater excess risk of coronary heart disease, stroke, vascular dementia, and heart failure in women compared to men. While the underlying mechanism that explains such greater excess risk is unknown, in the current meta-analysis we hypothesized that we would find a similar sex difference in the relationship between diabetes and peripheral arterial disease (PAD).

Methods

PubMed MEDLINE, the Cochrane Database of Systematic Reviews, and Embase were systematically searched for prospective population-based cohort studies, with no restriction on publication date, language, or country. We included studies that reported the relative risk (RR), and its variability, for incident PAD associated with diabetes in both sexes. We excluded studies that did not adjust at least for age, and in which participants had pre-existing PAD. In cases where sex-specific results were not reported, study authors were contacted. Random-effects meta-analyses with inverse variance weighting were used to obtain summary sex-specific RRs and the women: men ratio of RRs for PAD. The Newcastle–Ottawa scale was used to assess study quality.

Results

Data from seven cohorts, totalling 2071,260 participants (49.8% women), were included. The relative risk for incident PAD associated with diabetes compared with no diabetes was 1.96 (95% CI 1.29–2.63) in women and 1.84 (95% CI 1.29–2.86) in men, after adjusting for potential confounders. The multiple-adjusted RR ratio was 1.05 (95% CI 0.90–1.22), with virtually no heterogeneity between studies (I² = 0%). All studies scored 6–8, on the Newcastle–Ottawa scale of 0–9, indicating good quality. Eleven of the 12 studies that met review inclusion criteria did not report sex-specific relative risk, and these data were collected through direct correspondence with the study authors.

Conclusion/interpretation

Consistent with other studies, we found evidence that diabetes is an independent risk factor for PAD. However, in contrast to similar studies of other types of cardiovascular disease, we did not find evidence that diabetes confers a greater excess risk in women compared to men for PAD. More research is needed to explain this sex differential between PAD and other forms of CVD, in the sequelae of diabetes. In addition, we found that very few studies reported the sex-specific relative risk for the association between diabetes and PAD, adding to existing evidence for the need for improved reporting of sex-disaggregated results in cardiovascular disease research.

Increased Reintervention After Infrainguinal Revascularization for Chronic Limb-Threatening Ischemia in Women

BACKGROUND

The objective of this study was to determine if there are gender-based differences in major adverse limb events after revascularization for chronic limb-threatening ischemia (CLTI) and to identify potential associated factors.

METHODS

This was a single-center retrospective analysis of 151 patients who underwent infrainguinal revascularization for CLTI between April 2013 and December 2015. Only the first revascularized limb was included in patients with bilateral CLTI. Demographic data and clinical outcomes were collected using electronic medical records.

RESULTS

The mean age was 68.1 ± 12.1 years, and 55 of 151 (36%) were women. Women were less likely to carry a diagnosis of hyperlipidemia (60% vs. 83%; P = 0.003), less likely to be on a statin medication (58% vs. 81%; P = 0.004), and less likely to undergo an infrapopliteal revascularization (60% vs. 77%; P = 0.04) compared with men. There were no differences between genders with regard to the Society for Vascular Surgery Wound Ischemia and Foot Infection stage at presentation or utilization of open versus endovascular intervention. During the median follow-up time of 678 days (interquartile range, 167-1277 days), 48 of 151 patients (32%) underwent reintervention on the threatened limb and 23 of 151 patients (15%) underwent major amputation. Women were more likely than men to need reintervention (P = 0.02). There was no difference between genders for major amputation (P = 0.48) or overall survival (P = 0.65). In a multivariable Cox proportional hazards model for reintervention that included gender, preoperative body mass index, hyperlipidemia, preoperative anticoagulation, and ischemia score ≥2 (all P < 0.20 in univariate analysis), female gender (hazard ratio [HR], 1.96 [1.10-3.54]; P = 0.02) and hyperlipidemia (HR, 2.32 [1.07-5.03]; P = 0.03) were significantly associated with increased rates of reintervention.

CONCLUSIONS

Women undergoing lower extremity revascularization for CLTI were more likely to require reintervention compared with men but had similar rates of limb preservation. Further study is required to understand potential causative factors to improve treatment outcomes in women.

Epidemiology of peripheral artery disease in Palestine

Background: Peripheral artery disease (PAD) is one of the most common manifestations of atherosclerosis affecting more than 200 million people globally but little is known about its epidemiology in Middle East populations, particularly in Arab countries. The present study was undertaken to assess the prevalence of PAD in the general population aged 40 years and more in Gaza-Palestine, and to determine the prevalence of its associated risk factors. Patients and methods: The study design was a cross-sectional with a stratified proportional sampling, involving the five governorates in Gaza Strip. We selected 1490 individuals aged age ≥ 40 years living in the area for more than 3 years. The questionnaire on lifestyle and cardiovascular risk factors was applied and the ankle-brachial index (ABI) was measured by Doppler examination in both legs in all participants. PAD was defined as an ABI ≤ 0.90. We excluded 92 participants (6 %) because of missing ABI or ABI > 1.40. Results: One-half of the 1398 participants had at least two associated cardiovascular risk factors, one-third were on aspirin and 15 % on statins. Overall, we found PAD in 191 (13.7 %) cases. This prevalence increased with age, and 18.7 % of adults older than 65 years had PAD. The prevalence was higher in females than in males (respectively 15.6 % vs 11.6 % p = 0.031). In the multivariate logistic regression model, significant associated factors with PAD in males were CAD (OR: 3.5; 95 % CI: 1.4-8.6), hypertension (OR: 2.8; 95 % CI: 1.3-6.1), and current smoking (OR: 2.7; 95 % CI: 1.1-6.6). In women, hypertension remains the main associated risk factor. Conclusions: Our study highlights the high prevalence of PAD in the Gazan community, mostly related to the high prevalence of cardiovascular risk factors and other cardiovascular conditions.

Global, regional, and national prevalence and risk factors for peripheral artery disease in 2015: an updated systematic review and analysis

BACKGROUND

Peripheral artery disease is a major cardiovascular disease that affected 202 million people worldwide in 2010. In the past decade, new epidemiological data on peripheral artery disease have emerged, enabling us to provide updated estimates of the prevalence and risk factors for peripheral artery disease globally and regionally and, for the first time, nationally.

METHODS

For this systematic review and analysis, we did a comprehensive literature search for studies reporting on the prevalence of peripheral artery disease in the general population that were published between Jan 1, 2011, and April 30, 2019, in PubMed, MEDLINE, Embase, the Global Health database, CINAHL, the Global Health Library, the Allied and Complementary Medicine Database, and ProQuest Dissertations and Theses Global. We also included the Global Peripheral Artery Disease Study of 2013 and the China Peripheral Artery Disease Study as sources. Peripheral artery disease had to be defined as an ankle-brachial index lower than or equal to 0·90. With a purpose-built data collection form, data on study characteristics, sample characteristics, prevalence, and risk factors were abstracted from all the included studies identified from the sources. Age-specific and sex-specific prevalence of peripheral artery disease was estimated in both high-income countries (HICs) and low-income and middle-income countries (LMICs). We also did random-effects meta-analyses to pool the odds ratios of 30 risk factors for peripheral artery disease in HICs and LMICs. UN population data were used to generate the number of people affected by the disease in 2015. Finally, we derived the regional and national numbers of people with peripheral artery disease on the basis of a risk factor-based model.

FINDINGS

We included 118 articles for systematic review and analysis. The prevalence of peripheral artery disease increased consistently with age. At younger ages, prevalence was slightly higher in LMICs than HICs (4·32%, 95% CI 3·01-6·29, vs 3·54%, 1·17-10·24, at 40-44 years), but the increase with age was greater in HICs than LMICs, leading to a higher prevalence in HICs than LMICs at older ages (21·24%, 15·22-28·90, vs 12·04%, 8·67-16·60, at 80-84 years). In HICs, prevalence was slightly higher in women than in men up to age 75 years (eg, 7·81%, 3·97-14·77, vs 6·60%, 3·74-11·38, at 55-59 years), whereas in LMICs little difference was found between women and men (eg, 6·40%, 5·06-8·05, vs 6·37%, 4·74-8·49, at 55-59 years). Overall, the global prevalence of peripheral artery disease in people aged 25 years and older was 5·56%, 3·79-8·55, and the prevalence estimate was higher in HICs than that in LMICs (7·37%, 4·35-13·66, vs 5·09%, 3·64-7·24). Smoking, diabetes, hypertension, and hypercholesterolaemia were major risk factors for peripheral artery disease. Globally, a total of 236·62 million people aged 25 years and older were living with peripheral artery disease in 2015, among whom 72·91% were in LMICs. The Western Pacific Region had the most peripheral artery disease cases (74·08 million), whereas the Eastern Mediterranean Region had the least (14·67 million). More than two thirds of the global peripheral artery disease cases were concentrated in 15 individual countries in 2015.

INTERPRETATION

Peripheral artery disease continues to become an increasingly serious public health problem, especially in LMICs. With the demographic trend towards ageing and projected rise in important risk factors, a larger burden of peripheral artery disease is to be expected in the foreseeable future.

FUNDING

None.

Body mass index and peripheral artery disease

BACKGROUND AND AIMS

An independent association of body mass index (BMI) with atherosclerotic cardiovascular disease is somewhat controversial and may differ by vascular bed. Sex-specific risk factors for atherosclerosis may further modify these associations. Obesity and peripheral artery disease (PAD) are both more prevalent in women. We sought to determine the association between PAD and BMI using a very large population-based study.

METHODS

Self-referred individuals at >20,000 US sites completed medical questionnaires including height and weight, and were evaluated by screening ankle brachial indices (ABI) for PAD (ABI<0.9).

RESULTS

Among 3,250,350 individuals, the mean age was 63.1 ± 10.5 years and 65.5% were women. The mean BMI was 27.7 ± 5.8 kg/m2. 27.8% of participants were obese (BMI ≥30 kg/m2) - 27.6% females, 28.1% males. Overweight individuals (BMI 25-29.9 kg/m2) exhibited the lowest prevalence of PAD. There was a J-shaped association of BMI with prevalent PAD. After adjustment for age and cardiovascular risk factors, underweight was associated with similarly increased odds of PAD (1.72 vs. 1.39, women and men, respectively). The association of obesity with PAD was predominant in women, with only a slight association of increasing BMI with PAD in men (OR = 2.98 vs. 1.37 for BMI ≥40 kg/m2).

CONCLUSIONS

Our study suggests that increasing BMI is a robust independent risk factor for PAD only in women. This observation requires validation, but highlights the need for further research on sex-specific risk and mechanisms of atherosclerosis.

Peripheral Arterial Disease: Supervised Exercise Therapy Through Cardiac Rehabilitation

Peripheral arterial disease (PAD) is frequently underdiagnosed and undertreated. This review identifies specific subgroups within older adults more likely to develop PAD, and describes methods to diagnose PAD and provide evidence in support of systematic referral to cardiac rehabilitation programs to enhance successful comprehensive management. Clear evidence and guidelines support the routine use of supervised exercise therapy to improve function, reduce risk of cardiovascular morbidity and mortality, and enhance the success of endovascular interventions.

Comparison of the ankle-brachial index with parameters of stiffness and peripheral arterial resistance assessed by photoplethysmography in elderly patients

BACKGROUND

The ankle-brachial index (ABI) uses the ratio between systolic blood pressures at the ankle and the arm to diagnose peripheral arterial disease (PAD) noninvasively. Photoplethysmography (PPG) measures and records changes to the blood volume in the human body using optical techniques.

OBJECTIVES

The objective of this study was to compare ABI with arterial stiffness and peripheral resistance parameters assessed using PPG in elderly patients and to propose a model for prediction of ABI.

METHODS

A cross-sectional, quantitative study was conducted. The sample comprised elderly patients seen at a medical specialties clinic at the Universidade do Sul de Santa Catarina (UNISUL), Brazil. Age, sex, body mass index (BMI), comorbidities, smoking, and physical activity were recorded. The variables obtained using PPG and ABI were compared using bivariate and multivariate linear regression, with an α error of 0.05.

RESULTS

A total of 93 elderly patients were assessed, 63.4% of whom were women. In 98.9% of cases, ABI was within normal limits. Comparison of ABI with variables acquired by PPG revealed significant associations with age. However, no significant associations were observed between ABI and PPG. The multivariate model indicated that only age, sex, and smoking were associated with ABI.

CONCLUSIONS

In conclusion, ABI and PPG exhibited associations with arterial aging, considering its correlation with age. However, ABI was only related to age, sex, and smoking. More studies are needed to evaluate the potential uses of PPG for screening for vascular diseases in ambulatory settings.

Sex-Specific Considerations in Guidelines Generation and Application

New knowledge about male-female differences in pathophysiology, diagnosis, and treatment is shifting the practice of medicine from a one-size-fits all approach to a more individualized process that considers sex-specific interventions at the point of care. In this article, we review how clinical practice guideline committees can incorporate a structured framework to determine whether sex-specific assessments of the quality of the evidence or the particular recommendations should be made. The process can be operationalized by societies who author clinical practice guidelines by developing formal policies to approach biological sex in a systematic way, and by ensuring that writing committees include an individual who will champion the formal appraisal of the literature for associations between sex and the outcomes of interest. Ongoing challenges are discussed, and solutions are provided for how to disaggregate the evidence, how to assess bias, how to improve search strategies, and what to do when the data are insufficient to make sex-specific recommendations. Application of sex-specific recommendations will involve routinely asking whether the presentation, diagnostic workup, or management might change for each patient if they were the opposite sex.