Low ankle-brachial index and risk of stroke

Dose-Response Association of Low and Normal Ankle Brachial Index With the Risk of Cardiovascular Disease Morbidity and Mortality

We quantitatively evaluated the dose-response association of low and normal ankle brachial index (ABI) with the risk of morbidity and mortality from cardiovascular diseases (CVDs). PubMed, Embase, and Web of Science were systematically searched for cohort studies. Random effects or fixed effects models were used to estimate the pooled relative risks (RRs) and 95% confidence intervals (95% CIs). Generalized least squares regression was used to assess study-specific dose-response associations per 0.1 ABI decrease. Restricted cubic splines were used to evaluate linear or nonlinear trends. Twelve cohort studies (57 031 participants) were included in this meta-analysis. For low vs normal ABI levels, the pooled RRs were 2.03 (95% CI, 1.72-2.41; I² = 52.9%; p_{heterogeneity}=0.030) and 2.29 (95% CI, 1.98-2.64; I² = 39.5%; p_{heterogeneity} =0.158) for CVD morbidity and CVD mortality, respectively. For per 0.1 ABI decrease from 1.40 the risk for CVD morbidity and CVD mortality increased by 8% (1.08, 95% CI 1.04-1.11) and 11% (1.11, 95% CI 1.07-1.15), respectively. Restricted cubic splines showed inverse linear associations for CVD morbidity and CVD mortality. As a non-invasive index, lower ABI was significantly associated with the increased risk of morbidity and mortality from CVDs in an inverse linear manner.

Peripheral artery disease and physical function in women with and without HIV

OBJECTIVES

Peripheral artery disease (PAD) is associated with decreased physical function and increased mortality in the general population. We previously found that PAD is common in middle-aged women with and without HIV infection, but its association with functional decline is unclear. We examine the contribution of PAD to functional decline in the Women's Interagency HIV Study, controlling for traditional cardiovascular risk factors and HIV-related factors.

METHODS

Analysis included 1839 participants (72% with HIV) with measured ankle-brachial index (ABI) and 4 m gait speed. ABI values categorized PAD severity. Linear models with repeated measures estimated the association of PAD severity with log-transformed gait speed after controlling for demographic, behavioral, and metabolic risk factors, and HIV/hepatitis C virus status.

RESULTS

Median age was 50 years and more than 70% were Black. Compared with normal ABI, there was a dose-response relationship between increasing PAD severity and slower gait speed in univariable analyses: 6% slower gait speed for low-normal ABI [95% confidence interval (CI): 4-9%], 10% for borderline PAD (95% CI: 6-13%), 14% for mild PAD (95% CI: 9-18%), and 16% for moderate-severe PAD (95% CI: 5-25%). PAD severity remained associated with slower gait speed in multivariable analyses. HIV/hepatitis C virus co-infection was independently associated with 9% (95% CI: 4-14%) slower gait speed compared with those with neither infection. Among women with HIV, neither CD4+ cell count nor HIV-RNA level was associated with gait speed.

CONCLUSION

In middle-aged women with and without HIV infection, greater PAD severity is associated with progressively slower gait speed. Early detection of subclinical PAD may decrease the risk of lower extremity functional impairment and its long-term health consequences.

Ankle-brachial index: more than a diagnostic test?

The ankle-brachial index (ABI) is the relationship between the systolic blood pressure taken at the ankle level and the brachial artery. A pathological ABI (<0.90 or >1.40) indicates the presence of peripheral artery disease (PAD). Many studies indicate the great utility of this test in the diagnosis of PAD due to its ease of use, reproducibility, low cost, and high cost-effectiveness. This evaluation can be directly correlated with cardiovascular morbidity and mortality; however, it has recently been confirmed that a low ABI can be a predictor of major cardiovascular events, as it is related to diabetes mellitus, chronic coronary disease, stroke, and more. The objective of this work was to review the current evidence on the importance of ABI in the diagnosis of PAD and its main role as a predictor of cardiovascular morbidity and mortality.

Effect of BMI on Central Arterial Reflected Wave Augmentation Index, Toe-Brachial Index, Brachial-Ankle Pulse Wave Velocity and Ankle-Brachial Index in Chinese Elderly Hypertensive Patients with Hemorrhagic Stroke

BACKGROUND

Hypertensive cerebral hemorrhage seriously endangers the health of the elderly. However, the relationship between obesity and arterial elasticity in hypertensive cerebral hemorrhage remains to be clarified. The purpose of our study is to explore the associations between body mass index (BMI) and central arterial reflected wave augmentation index (cAIx), toe-brachial index (TBI), brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI) in the elderly hypertensive patients with hemorrhagic stroke.

MATERIALS AND METHODS

A total of 502 elderly hypertensive patients with hemorrhagic stroke and 100 healthy controls were collected. According to the BMI, patients were divided into normal BMI, overweight, obesity, and obese groups. The multivariate logistic regression model was used to establish a risk model for elderly hypertensive hemorrhagic stroke.

RESULTS

Compared with the normal BMI group, systolic blood pressure (SBP), diastolic blood pressure (DBP), cAIx, and baPWV in the abnormal BMI group were significantly increased (P < 0.05), while TBI and ABI were significantly decreased (P < 0.05). Logistic regression showed that BMI (OR = 1.031, 95%CI: 1.009-1.262), cAIx (OR = 1.214, 95%CI: 1.105-1.964), TBI (OR = 0.913, 95%CI: 0.885-0.967), baPWV (OR = 1.344, 95%CI: 1.142-2.147), and ABI (OR = 0.896, 95%CI: 0.811-0.989) are important factors for the occurrence of hemorrhagic stroke in the elderly hypertensive patients. ROC curve analysis showed that the AUC of cAIx, TBI, baPWV, ABI, and BMI were 0.914, 0.797, 0.934, 0.833, and 0.608, respectively. The final prediction model of hemorrhagic stroke elderly hypertensive patients was Y_(P)= 65.424 + 0.307(cAIx) - 13.831(TBI) + 0.012(baPWV) - 0.110(ABI) + 0.339(BMI).

CONCLUSIONS

Obesity is associated with decreased arterial elasticity. Therefore, reasonable weight management of the elderly may be of great significance for reducing the risk of hemorrhagic stroke in patients with hypertension.

Ankle-Brachial Index Is Independently Associated With Cardiovascular Outcomes and Foot Ulcers in Asian Patients With Type 2 Diabetes Mellitus

BACKGROUND AND AIMS

The ankle-brachial index (ABI) is an efficient tool for objectively documenting the presence of lower-extremity peripheral arterial disease (PAD). The predictive factors of cardiovascular events and diabetic foot ulcer were not clear from the ABI examination in Taiwanese patients with type 2 diabetes mellitus (DM).

METHODS

We enrolled 482 patients with type 2 DM who regularly visited the outpatient department of Chang Gung Memorial Hospital and received ABI as well as brachial-ankle pulse wave velocity (ba-PWV) examinations from 2010 to 2017. Age, gender, PAD symptoms, comorbidities, family history of chronic diseases, lifestyle (smoking, alcohol consumption, and exercise), height, weight, waist circumference, monofilament testing and foot ulcer status were studied.

RESULTS

There were 104 (22%) patients (mean age, 67.8 years) with the ABI <1.0. These patients with low ABI (ABI<1.0) had a significantly older age (p=0.001), higher delta PWV (p<0.001), higher rates of stroke (p=0.007), myocardial infarction (p=0.016), and foot ulcer (p=0.039). In a multivariable analysis model, the adjusted odds ratio (aOR) for myocardial infarction, stroke, and foot ulcers associated with low ABI were 1.219 (0.397-3.743, p=0.729), 1.204 (0.556-2.610, p=0.638), and 2.712 (1.199-6.133, p=0.017), respectively. The patients with low PWV (PWV<1400 cm/s) were significantly younger (p<0.001) and had a lower rate of hypertension (p<0.001), and higher percentages of stroke (p=0.027) and dialysis (p=0.041) family history.

CONCLUSIONS

Low ABI was associated with cardiovascular events and diabetic foot ulcer independently in patients with type 2 DM.

The ankle-brachial index and risk of incident stroke in Chinese hypertensive population without atrial fibrillation: A cross-sectional study

We aimed to evaluate the relation of the ankle–brachial index (ABI) with the prevalence of stroke and to examine any possible effect modifiers among hypertensive patients without atrial fibrillation. A total of 10 750 subjects with hypertension aged 27‐96 years were included in the current study. The outcome was a stroke. Odds ratios of stroke concerning ABI were calculated using multivariate logistic regression models. Among 10 750 hypertensive participants, 690 (6.42%) had a stroke. Multivariate logistic analyses showed that ABI was negatively correlated with the prevalence of stroke (per SD increment; adjusted OR, 0.88; 95% CI, 0.82‐0.94). Compared with participants in Q 1, the odds ratios (95% CI) for those in the Q2 (1.05 to 1.10), Q3 (1.10 to 1.15), and Q4 (≥1.15) were 0.71 (0.56, 0.90), 0.87 (0.70, 1.08), and 0.81 (0.65, 1.01), respectively. However, compared with higher ABI value, lower ABI value (<1.05) would significantly increase the odds of stroke (OR: 1.26, 95% CI [1.05‐1.50]), especially in the elderly over 65 years old. A generalized additive model and a smooth curve fitting showed that there existed an L‐shaped association between ABI and the prevalence of stroke. Our results suggest that an L‐shaped association between ABI and the prevalence of stroke was found in general hypertensive patients, with a turning point at about 1.05. Compared with higher ABI value, lower ABI value (<1.05) would significantly increase the prevalence of stroke (OR: 1.26, 95% CI [1.05‐1.50]), especially in the elderly over 65 years old.

Carotid plague formation is associated with ankle-brachial index in elderly people

AIMS

This study aimed at examining whether ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) were independently associated with carotid Intima-media thickness (CIMT) or carotid artery plaque (CAP) in elderly people.

METHODS

A cross-sectional analysis was performed in 155 individuals aged over 75 years who underwent the measurements of ABI and baPWV. Low ABI was defined as ABI ≤ 1.0. High baPWV was defined as baPWV > 2000 cm/s. The CIMT and CAP were measured with a B-mode tomographic ultrasound system.

RESULTS

Neither ABI nor baPWV was associated with CIMT in this elderly population. The group with low ABI (≤ 1.0) was significantly associated with a higher prevalence of carotid plaque (P = 0.001), while the relationship between baPWV and prevalence of carotid plaque was not found. Linear regression analysis showed that the value of ABI was significantly associated with the thickness of carotid plaque. Even in the full adjusted model, each 0.01unit ABI decreasing still increased 0.1663 mm of carotid plaque thickness (P = 0.004). Logistic Regression Analysis demonstrated that ABI lower than 1.0 had predictive value in the formation of carotid plaque with top quartile thickness (OR 2.834, 95% CI 1.131-7.099, P = 0.026). Furthermore, individuals with low ABI (≤ 1.0) were more likely to form hypoechoic carotid plaques according to ultrasonography.

CONCLUSION

Low ABI but not high baPWV was associated with the formation of carotid plaque. Furthermore, ABI was significantly associated with the thickness and morphology of carotid plaque in elderly people.

Prevalence of Lower Extremity Arterial Disease as Measured by Low Ankle-Brachial Index in Patients with Acute Cerebral Ischemic Events

BACKGROUND

Low ankle-brachial index (ABI) of ≤0.9 is diagnostic of lower extremity arterial disease (LEAD). It is also a strong marker of generalized atherosclerosis. The objective of this study was to assess the prevalence of low ABI in patients with acute cerebral ischemic events (ACIE): ischemic stroke (IS) or transient ischemic attack (TIA).

METHODS

We compared 150 inpatients with ACIE to 50 inpatient controls and assessed risk factors, ABI measurements, and Duplex ultrasound of the cervical vessels.

RESULTS

Low ABI was seen in 69 patients (46%) in the ACIE group and in 8 (16%) in the control group; p < 0.01. The mean and median ABI values in the ACIE group were 0.88 (SD = 0.22) and 0.91 (0.24-1.33), which were significantly lower than in the control group: 1.04 (SD = 0.16) and 1.0 (0.66-1.36); p < 0.0001, respectively. Coronary artery disease, carotid stenosis of ≥50% and smoking were risk factors, which were associated with significantly lower ABI in the study group; the ABI with risk factors vs. without was 0.85 vs. 0.92 (coronary artery disease); p < 0.05, 0.7 vs. 0.92; (carotid stenosis) p < 0.001 and 0.83 vs. 0.98; (smoking) p < 0.001, respectively.

CONCLUSION

Our study demonstrated that patients with ACIE have significantly higher involvement of another vascular bed as LEAD. Coronary artery disease, carotid stenosis ≥50% and smoking were main risk factors associated with coexistence of LEAD and ACIE.

Risk factors for calcification of the vertebrobasilar arteries in cardiovascular patients referred for a head CT, the SMART study

BACKGROUND AND PURPOSE

Vertebrobasilar artery calcification (VBAC) has been associated with increased stroke occurrence. Little is known on VBAC risk factors, especially for patients with cardiovascular disease. We aimed to assess risk factors associated with VBAC in a cohort of cardiovascular patients referred for a head computed tomography (CT) scan.

MATERIALS AND METHODS

All patients who underwent a clinically indicated, unenhanced, thin slice head CT 6 months before or after inclusion in the SMART study were included. CTs were assessed for presence of VBAC (dichotomously). Relative risks of the associations of age, sex, diabetes mellitus (DM), obesity, body mass index, estimated glomerular filtration rate, hypertension, hyperlipidemia, use of lipid lowering medication, smoking status, high sensitivity C-reactive protein, ankle-brachial index (ABI; ≤0.90, ≥1.30, continuous), internal carotid artery stenosis ≥70%, and carotid intima-media thickness (IMT) with VBAC were estimated using Poisson regression analysis with robust standard errors, adjusted for age and sex.

RESULTS

Of the 471 patients included (57% male, median age 58 [interquartile range 47-63]), 117 (24.8%) showed VBAC. Presence of VBAC was associated with older age (RR per 10 years=1.70 [95%CI 1.46-1.99]), DM (RR=1.45 [95%CI 1.03-2.06]), obesity (RR=1.53 [95%CI 1.10-2.12]), ABI ≤0.90 (RR=1.57 [95%CI 1.02-2.41]), and an increased carotid IMT (RR=2.60 per mm [95%CI 1.20-5.62]). Other measurements were not associated with VBAC.

CONCLUSIONS

We identified several markers associated with VBAC in patients with cardiovascular disease referred for a head CT. Future investigation into the relationship between VBAC and stroke is warranted to determine the potential of VBAC in stroke prevention.

Entering Cardiac Rehabilitation With Peripheral Artery Disease: A RETROSPECTIVE COMPARISON TO CORONARY ARTERY DISEASE

PURPOSE

Supervised exercise is recommended for patients with peripheral artery disease (PAD) and patients with coronary artery disease (CAD). Both conditions share common etiology as atherosclerotic diseases. The clinical profile, cardiorespiratory fitness, and exercise prescriptions of PAD, CAD, and patients with concomitant PAD and CAD (BOTH) have yet to be compared upon entry into cardiac rehabilitation (CR).

METHODS

Cardiopulmonary, demographic, and anthropometric assessments were conducted at entry to CR between January 2006 and December 2017.

RESULTS

Among 9701 consecutively enrolled patients, there were 94.6% with CAD (n = 9179), 1.5% with PAD (n = 143), and 3.9% with BOTH (n = 379). Only 5.4% (n = 522) of all patients entering CR had a diagnosis of PAD. Compared with CAD, patients with PAD and BOTH were older (mean ± SD = 62.5 ± 11.1 vs 67.9 ± 11.4 and 69.2 ± 9.8 yr, P < .01), had higher resting systolic blood pressure (124 ± 17 vs 130 ± 17 and 133 ± 18 mm Hg, P < .01), had lower cardiorespiratory fitness (19.7 ± 6.3 vs 15.6 ± 4.8 and 15 ± 4.5 mL/kg/min, P < .01), and were more likely to have diabetes (25% vs 35% and 41%, P < .01), abdominal obesity (39% vs 54% and 51%, P < .01), and initially prescribed lower-intensity exercise (84.4 ± 14.1 vs 74.1 ± 15.7 and 70.0 ± 14.6 m/min exercise pace, P < .01), reflecting the complex nature of patients diagnosed with PAD.

CONCLUSIONS

Patients referred with PAD have a cardiovascular risk profile that places them at a greater risk for a repeat or first cardiac event compared with patients with CAD. Referral to structured exercise and risk factor modification programs should be considered to aid in the management of PAD.

Atherosclerosis in Chronic Kidney Disease: More, Less, or Just Different?

Patients with chronic kidney disease (CKD) are at an increased risk of premature mortality, mainly from cardiovascular causes. The association between CKD on hemodialysis and accelerated atherosclerosis was described >40 years ago. However, more recently, it has been suggested that the increase in atherosclerosis risk is actually observed in early CKD stages, remaining stable thereafter. In this regard, interventions targeting the pathogenesis of atherosclerosis, such as statins, successful in the general population, have failed to benefit patients with very advanced CKD. This raises the issue of the relative contribution of atherosclerosis versus other forms of cardiovascular injury such as arteriosclerosis or myocardial injury to the increased cardiovascular risk in CKD. In this review, the pathophysiogical contributors to atherosclerosis in CKD that are shared with the general population, or specific to CKD, are discussed. The NEFRONA study (Observatorio Nacional de Atherosclerosis en NEFrologia) prospectively assessed the prevalence and progression of subclinical atherosclerosis (plaque in vascular ultrasound), confirming an increased prevalence of atherosclerosis in patients with moderate CKD. However, the adjusted odds ratio for subclinical atherosclerosis increased with CKD stage, suggesting a contribution of CKD itself to subclinical atherosclerosis. Progression of atherosclerosis was closely related to CKD progression as well as to the baseline presence of atheroma plaque, and to higher phosphate, uric acid, and ferritin and lower 25(OH) vitamin D levels. These insights may help design future clinical trials of stratified personalized medicine targeting atherosclerosis in patients with CKD. Future primary prevention trials should enroll patients with evidence of subclinical atherosclerosis and should provide a comprehensive control of all known risk factors in addition to testing any additional intervention or placebo.

Ankle-brachial index and peripheral artery disease are not related to restless legs syndrome

OBJECTIVE

Our aim was to investigate the relationship between impaired peripheral arterial circulation as measured by ankle-brachial index (ABI) and restless legs syndrome (RLS) in the general population.

METHODS

Data are derived from three independent, German population-based, prospective studies: the control sample of BiDirect (N = 966), the second follow-up of SHIP (N = 2333), and a subsample of SHIP-Trend (N = 1269). RLS was assessed with questions based on the RLS minimal criteria. ABI was measured with an automated method in BiDirect and with Doppler ultrasound in both SHIP studies. An ABI score below 0.9 was indicative of peripheral arterial disease (PAD). Co-morbidities, medications and behavioural factors were self-reported. Additional measurements included body mass index and haemoglobin from blood serum. For BiDirect, a follow-up with identical methodology was performed after a median of 2.5 years.

RESULTS

In cross-sectional analyses, decreased ABI was not significantly associated with RLS as outcome in multivariable logistic regression models adjusted for several potential confounders (BiDirect: odds ratio (OR) = 1.07 for a -0.1 change in ABI, 95% confidence interval (CI): 0.81-1.42, p = 0.62; SHIP-2: OR = 0.99, CI: 0.85-1.16, p = 0.94; SHIP-Trend: OR = 0.99, CI: 0.87-1.13, p = 0.88). Similar non-significant results were achieved using PAD (instead of ABI) as an independent variable. In BiDirect, baseline ABI was not a significant predictor of incident RLS in longitudinal analysis (OR = 0.77, CI: 0.53-1.12, p = 0.17).

CONCLUSION

Results from three independent studies suggest that reduced ABI is not a risk factor for RLS in the general population.

Ankle-brachial index and brachial-ankle pulse wave velocity are risk factors for ischemic stroke in patients with Type 2 diabetes

The incidence of ischemic stroke in patients with diabetes is increasing. While brachial-ankle pulse wave velocity (BaPWV) and ankle-brachial index (ABI) are known to be associated with ischemic cardiovascular and cerebrovascular diseases, whether these measures predict the risk of ischemic cerebrovascular disease in diabetic patients remains unclear. 117 patients with type 2 diabetes were enrolled in this study. According to the results of head magnetic resonance imaging, the patients were divided into a diabetes-only group (n = 55) and a diabetes and ischemic stroke group (n = 62). We then performed ABI and BaPWV examinations for all patients. Compared with the diabetes-only group, we found decreased ABI and increased BaPWV in the diabetes and ischemic stroke group. Multivariate logistic regression analyses revealed that BaPWV and ABI were risk factors for ischemic stroke in patients with type 2 diabetes. Our findings indicate that decreased ABI and increased BaPWV are objective indicators of increased risk of ischemic stroke in patients with type 2 diabetes.

Prognostic implications of the Ankle Brachial Index in patients with acute ischemic stroke: A meta-analysis

BACKGROUND

The ankle brachial index (ABI) is recognized as a marker of atherosclerotic disease. The detection of ABI may improve the risk stratification.

METHODS

We systematically searched Pubmed and Embase (from the earliest date to October 2015) for studies evaluating the prognostic value of ABI in patients with acute ischemic stroke. Stroke or cardiovascular events, mortality and functional outcomes were analyzed.

RESULTS

Seventeen studies, containing 9404 patients, were included. The mean age of participants in each study ranged from 64 to 79 years. The prevalence of low ABI varied from 7.4% to 40.5%. In this quantitative analysis, we found that low ABI increased the risk of composite outcomes (myocardial infarction or stroke or mortality), disability and mortality.

CONCLUSION

The detection of ABI may help to identify high-risk patients for secondary stroke prevention.

The association between ankle-brachial index and asymptomatic cranial-carotid stenosis: a population-based, cross-sectional study of 5440 Han Chinese

BACKGROUND AND PURPOSE

Routine screening for asymptomatic cranial-carotid stenosis (ACCS) is controversial and recommendation in clinical practice is vague. The ankle-brachial index (ABI) is reported as a predictor for cardiovascular disease. However, there is a scarcity of data about the association between abnormal ABI and ACCS. A population-based cross-sectional study was conducted to explore the relationship between ABI and ACCS.

METHODS

A sample of 5440 Chinese adults aged 40-94 years old was recruited from 2010 to 2011. The ABI was measured using a portable Doppler device and ACCS was evaluated by bilateral carotid duplex ultrasound and portable examination devices. A logistic regression model was used to analyse the association between ABI and ACCS after adjusting for potential confounding factors.

RESULTS

A low ABI was associated with ACCS [odds ratio (OR) 1.95, 95% confidence interval (CI) 1.42-2.67] after adjusting for potential confounders. When the data were stratified by age and sex, the correlation remained statistically significant in the male (OR 2.32, 95% CI 1.60-3.37) and elderly (OR 3.07, 95% CI 1.97-4.78) subgroups compared to the female (OR 1.26, 95% CI 0.67-2.39) and middle-aged groups (OR 1.27, 95% CI 0.77-2.12), respectively.

CONCLUSION

This study demonstrated that low ABI is a significant risk factor for ACCS in male and elderly Chinese adults.

Brachial-ankle pulse wave velocity and ankle-brachial index are complementary tools for transcranial Doppler ultrasonography in early diagnosis of intracranial arterial stenosis/occlusion in patients with acute ischemic stroke

The aim of this study was to explore whether brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) are suitable to serve as complementary tools for TCD in early diagnosis of intracranial arterial stenosis/occlusion in patients with acute ischemic stroke (AIS). A total of 52 patients with AIS onset and 52 age-matched healthy controls were included in this study. All participants received TCD detection, and baPWV and ABI were measured. Computed topography (CT)/magnetic resonance imaging (MRI) was applied to confirm diagnosis. TCD data from all participants was collected and reviewed to diagnose stenosis and occlusion of the major intracranial arteries. Receiver operating characteristic (ROC) analysis and logistic regression analysis were used to assess and compare the diagnostic accuracy of the various diagnostic approaches. We found that a combination of TCD with either baPWV or ABI, or a combination of the three provided a significantly higher area under the curve (AUC) in detecting stenosis or occlusion in various intracranial arteries, excluding the anterior cerebral artery (ACA), when compared to TCD alone, thereby demonstrating that these combined approaches provide improved diagnostic accuracy. In conclusion, our findings suggest that both baPWV and ABI are suitable complementary tools for TCD in early diagnosis of intracranial arterial stenosis/occlusion in AIS patients and that these combinations may assist in facilitating the diagnostic process associated with this disease.

Ankle-Brachial Index and Recurrent Stroke Risk: Meta-Analysis

BACKGROUND AND PURPOSE

The ankle-brachial index (ABI) is a fast, cheap, noninvasive indicator of atherosclerotic burden that may also be a predictor of stroke recurrence. In this systematic review and meta-analysis, we sought to explore ABI's merit as a marker for stroke recurrence and vascular risk by synthesizing the data currently available in stroke literature.

METHODS

We searched Embase, MEDLINE, and Pubmed databases for prospective cohort studies that included consecutive patients with stroke and transient ischemic attack, measured ABI at baseline, and performed a follow-up assessment at least 12 months after initial stroke or transient ischemic attack. The following end points were chosen for our analysis: recurrent stroke and combined vascular end point (recurrent vascular event or vascular death). Crude risk ratios and adjusted Cox proportional hazard ratios were combined separately using the random-effects model. Study-level characteristics (eg, percent of cohort with a history of hypertension, average cohort age, level of adjustment, and mean follow-up duration) were included as covariates in a metaregression analysis.

RESULTS

We identified 11 studies (5374 patients) that were not significantly heterogeneous. Pooling adjusted hazard ratios showed that low ABI was associated with both an increased hazard of recurrent stroke (hazard ratio, 1.70; 95% confidence interval, 1.10-2.64) and an increased risk of vascular events or vascular death (hazard ratio, 2.22; 95% confidence interval, 1.67-2.97).

CONCLUSION

Our results confirm the positive association between ABI and stroke recurrence. Further studies are needed to see whether inclusion of ABI will help improve the accuracy of prediction models and management of stroke patients.

The association of ankle-brachial index with silent cerebral small vessel disease: results of the Atahualpa Project

BACKGROUND

An abnormal ankle-brachial index has been associated with overt stroke and coronary heart disease, but little is known about its relationship with silent cerebral small vessel disease.

AIM

To assess the value of ankle-brachial index as a predictor of silent small vessel disease in an Ecuadorian geriatric population.

METHODS

Stroke-free Atahualpa residents aged ≥60 years were identified during a door-to-door survey. Ankle-brachial index determinations and brain magnetic resonance imaging were performed in consented persons. Ankle-brachial index ≤0.9 and ≥1.4 were proxies of peripheral artery disease and noncompressible arteries, respectively. Using logistic regression models adjusted for age, gender, and cardiovascular health status, we evaluated the association between abnormal ankle-brachial index with silent lacunar infarcts, white matter hyperintensities, and cerebral microbleeds.

RESULTS

Mean age of the 224 participants was 70 ± 8 years, 60% were women, and 80% had poor cardiovascular health status. Ankle-brachial index was ≤0.90 in 37 persons and ≥1.4 in 17. Magnetic resonance imaging showed lacunar infarcts in 27 cases, moderate-to-severe white matter hyperintensities in 47, and cerebral microbleeds in 26. Adjusted models showed association of lacunar infarcts with ankle-brachial index ≤ 0.90 (OR: 3.72, 95% CI: 1.35-10.27, P = 0.01) and with ankle-brachial index ≥ 1.4 (OR: 3·85, 95% CI: 1.06-14.03, P = 0.04). White matter hyperintensities were associated with ankle-brachial index ≤ 0.90 (P = 0.03) and ankle-brachial index ≥ 1.4 (P = 0.02) in univariate analyses. There was no association between ankle-brachial index groups and cerebral microbleeds.

CONCLUSIONS

In this population-based study conducted in rural Ecuador, apparently healthy individuals aged ≥60 years with ankle-brachial index values ≤0.90 and ≥1.4 are almost four times more likely to have a silent lacunar infarct. Ankle-brachial index screening might allow recognition of asymptomatic people who need further investigation and preventive therapy.