High ankle brachial index predicts high risk of cardiovascular events amongst people with peripheral artery disease

Editor's Choice - Prognostic Factors and Models to Predict Mortality Outcomes in Patients with Peripheral Arterial Disease: A Systematic Review

OBJECTIVE

Predicting adverse outcomes in patients with peripheral arterial disease (PAD) is a complex task owing to the heterogeneity in patient and disease characteristics. This systematic review aimed to identify prognostic factors and prognostic models to predict mortality outcomes in patients with PAD Fontaine stage I - III or Rutherford category 0 - 4.

DATA SOURCES

PubMed, Embase, and Cochrane Database of Systematic Reviews were searched to identify studies examining individual prognostic factors or studies aiming to develop or validate a prognostic model for mortality outcomes in patients with PAD.

REVIEW METHODS

Information on study design, patient population, prognostic factors, and prognostic model characteristics was extracted, and risk of bias was evaluated.

RESULTS

Sixty nine studies investigated prognostic factors for mortality outcomes in PAD. Over 80 single prognostic factors were identified, with age as a predictor of death in most of the studies. Other common factors included sex, diabetes, and smoking status. Six studies had low risk of bias in all domains, and the remainder had an unclear or high risk of bias in at least one domain. Eight studies developed or validated a prognostic model. All models included age in their primary model, but not sex. All studies had similar discrimination levels of > 70%. Five of the studies on prognostic models had an overall high risk of bias, whereas two studies had an overall unclear risk of bias.

CONCLUSION

This systematic review shows that a large number of prognostic studies have been published, with heterogeneity in patient populations, outcomes, and risk of bias. Factors such as sex, age, diabetes, hypertension, and smoking are significant in predicting mortality risk among patients with PAD Fontaine stage I - III or Rutherford category 0 - 4.

Associations between physical activity and ankle-brachial index: the Swedish CArdioPulmonary bioImage Study (SCAPIS)

BACKGROUND

The ankle-brachial index (ABI) is the ratio of the ankle and brachial systolic blood pressures. In the clinical setting, low ABI (< 0.9) is an indicator of peripheral atherosclerosis, while high ABI (> 1.4) is a sign of arterial stiffness and calcification. The purpose of the current study was to investigate the association between ABI and physical activity levels, measured by accelerometer.

METHODS

The Swedish CArdioPulmonary bioImage Study (SCAPIS) is a Swedish nationwide population-based cross-sectional cohort for the study of cardiovascular and pulmonary diseases, in which individuals aged 50-64 years were randomly invited from the general population. The study population with data on ABI, physical activity, and sedentary time based on accelerometry was 27,737. Differences between ABI categories and associations to sedentary behavior, moderate to vigorous physical activity (MVPA), and other metabolic characteristics were compared. ABI was categorized as low, ABI ≤ 0.9, borderline, ABI 0.91-0.99, normal, ABI 1.0-1.39, and high, ABI ≥ 1.4.

RESULTS

Prevalence of low ABI was higher in the most sedentary quartiles compared to the least sedentary (0.6% vs. 0.1%, p < 0.001). The most sedentary individuals also exhibited higher BMI, higher prevalence of diabetes and hypertension. The proportion of wake time spent in MVPA was lowest in those with low ABI (0.033 ± 0.004; p < 0.001) and highest in those with ABI > 1.4 (0.069 ± 0.001; p < 0.001) compared to those with normal ABI. Compared to normal ABI, the proportion of sedentary time was highest in those with low ABI (0.597 ± 0.012; p < 0.001) and lowest in those with ABI > 1.4 (0.534 ± 0.002; p = 0.004).

CONCLUSION

This population-based study shows that middle-aged individuals with ABI > 1.4 have the highest level of physical activity, while individuals with a lower ABI, especially those with ABI < 0.9, are less active and spend more time sedentary. Future studies are needed to understand the relationships between ABI, physical activity, and the risk of peripheral arterial and cardiovascular disease in the general population.

Counseling Intervention and Cardiovascular Events in People With Peripheral Artery Disease: A Post Hoc Analysis of the BIP Randomized Clinical Trial

Importance

It is unclear whether counseling to promote walking reduces the risk of major adverse cardiovascular events (MACE) in people with peripheral artery disease (PAD).

Objective

To test whether a counseling intervention designed to increase walking reduced the risk of MACE in patients with PAD.

Design, Setting, and Participants

The BIP trial was a randomized clinical trial, with recruitment performed between January 2015 and July 2018 and follow-up concluded in August 2023. Participants with walking impairment due to PAD from vascular departments in the Australian cities of Brisbane, Sydney, and Townsville were randomly allocated 1:1 to the intervention or control group. Data were originally analyzed in March 2024.

Intervention

Four brief counseling sessions aimed to help patients with the challenges of increasing physical activity.

Main Outcomes and Measures

The primary outcome was the between-group difference in risk of MACE, which included myocardial infarction (MI), stroke, and cardiovascular death. The relationship between Intermittent Claudication Questionnaire (ICQ) scores, PAD Quality of Life (PADQOL) scores, and MACE was examined with Cox proportional hazard regression analyses.

Results

A total of 200 participants were included, with 102 allocated to the counseling intervention (51.0%) and 98 to the control group (49.0%).Participants were followed up for a mean (SD) duration of 3.5 (2.6) years. Median (IQR) participant age was 70 (63-76) years, and 56 of 200 participants (28.0%) were female. A total of 31 individuals had a MACE (composed of 19 MIs, 4 strokes, and 8 cardiovascular deaths). Participants allocated to the intervention were significantly less likely to have a MACE than participants in the control group (10 of 102 participants [9.8%] vs 21 of 98 [21.4%]; hazard ratio [HR], 0.43; 95% CI, 0.20-0.91; P = .03). Greater disease-specific quality of life (QOL) scores at 4 months (ICQ: HR per 1-percentage point increase, 0.97; 95% CI, 0.95-0.99; P < .001; PADQOL factor 3 [symptoms and limitations in physical functioning]: HR per 1-unit increase, 0.91; 95% CI, 0.84-0.98; P = .01) and at 12 months (ICQ: HR per 1-percentage point increase, 0.97; 95% CI, 0.95-0.99; P = .003; PADQOL factor 3: HR per 1-unit increase, 0.91; 95% CI, 0.84-0.98; P = .02) were associated with a lower risk of MACE. In analyses adjusted for ICQ or PADQOL factor 3 scores at either 4 or 12 months, allocation to the counseling intervention was no longer significantly associated with a lower risk of MACE.

Conclusions and Relevance

This post hoc exploratory analysis of the BIP randomized clinical trial suggested that the brief counseling intervention designed to increase walking may reduce the risk of MACE, possibly due to improvement in QOL.

Trial Registration

anzctr.org.au Identifier: ACTRN12614000592640.

Peripheral Artery Disease among a High-Risk Asian Population with Ischaemic Stroke, Cardiovascular Disease, or Diabetes Mellitus

Background: Peripheral artery disease (PAD) affects more than 100 million people globally. Most PAD studies have been performed among predominantly White populations-less is known about other ethnicities. The aim of this cross-sectional study was to determine the prevalence and risk factors of PAD in a high-risk Asian population with ischaemic stroke (IS), myocardial infarction, unstable angina (CVD), or diabetes mellitus (DM). Methods: Patients admitted for IS, CVD, or DM were recruited. Data were collected on age, sex, body mass index (BMI), index condition (CVD, IS, DM), history of hypertension, DM, hypercholesterolaemia, cigarette smoking, and claudication. The Edinburgh Claudication Questionnaire was administered, the ankle brachial index (ABI) was determined, and PAD was diagnosed if ABI was ≤0.9. Results: Of the 450 subjects recruited, 150 were placed in each index disease group, the mean age was 61.9 ± 10.32 years, 43.1% were female, and the mean BMI was 23.9 ± 4.3. Hypertension was reported in 59.3%, DM in 63.6%, hypercholesterolaemia in 39.6%, and smoking in 42.9% of patients. The prevalence of PAD was 27.1%, 22.0% in IS, 29.3% in CAD, and 30.0% in DM. PAD was associated with increasing age (adjusted odds ratio (aOR) 1.04/year, 95% confidence interval [CI] 1.01-1.06; p < 0.001), reduced BMI (aOR 0.94, 95% CI 0.89-0.99; p = 0.026), DM (aOR 1.59, 95% CI 1.20-3.18; p = 0.007), and hypercholesterolaemia (aOR 1.82, 95% CI 1.17-2.28; p = 0.007). It was more frequent in non-lacunar versus lacunar acute IS, non-ST segment elevation versus ST-segment elevation acute myocardial infarction, and insulin-treated versus non-insulin-treated DM. Conclusions: Our study showed a high prevalence of PAD among high-risk Asian patients. This was associated with increasing age, DM, and hypercholesterolaemia and inversely associated with BMI. Different rates were found in sub-groups of IS, CVD, and DM. Systematic approaches were used to identify these high-risk individuals and to improve their outcomes.

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

PURPOSE

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

METHODS

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

FINDINGS

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

IMPLICATIONS

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

The association of arterial stiffness with estimated excretion levels of urinary sodium and potassium and their ratio in Chinese adults

Arterial stiffness is an independent cardiovascular risk factor. However, the association between sodium/potassium intake and arterial stiffness in the Chinese population is unclear. Therefore, we performed a large, community-based cross-sectional study to reach a more definitive conclusion. The study was conducted at the Third Xiangya Hospital in Changsha between August 2017 and September 2019. Urinary sodium, potassium, and creatinine levels were tested from spot urine samples during physical examinations of each recruited participant. The 24-hour estimated urinary sodium excretion (eUNaE) and estimated urinary potassium excretion (eUKE) levels were calculated using the Kawasaki formula (used as a surrogate for intake). The brachial-ankle pulse wave velocity (baPWV) and ankle brachial index (ABI) were measured using an automatic waveform analyzer. In 22,557 subjects with an average age of 49.3 ± 10.3 years, the relationships of the ABI and baPWV with the levels of eUNaE, eUKE and the ratio of sodium to potassium (Na/K ratio) were analyzed. A significant negative relationship was found between the eUKE and baPWV levels (β = 2.41, p < 0.01), whereas the Na/K ratio was positively associated with baPWV (β = 2.46, p < 0.01), especially in the overweight and hypertensive populations (both pinteraction = 0.04). The association of eUNaE quartiles with baPWV presented a J-shaped curve after adjusting for confounders. In addition, a positive association was observed between the Na/K ratio and the ABI (β = 0.002, p < 0.01). In this study, high potassium and/or low sodium intake was further confirmed to be related to vascular stiffness in Chinese individuals.

Current Management of Peripheral Artery Disease: Focus on Pharmacotherapy

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

Update on the pathophysiology and medical treatment of peripheral artery disease

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