Association of High Ankle Brachial Index With Incident Cardiovascular Disease and Mortality in a High-Risk Population

Warfarin and DOAC impact on cardiovascular and limb outcomes in patients with peripheral arterial disease

Background: Peripheral arterial disease (PAD) increases cardiovascular (CV) morbidity and mortality, but remains underdiagnosed and undertreated. Several trials support low-dose direct oral anticoagulant (DOAC) use in PAD treatment, although this has yet to be widely adopted in clinical practice. Patients and methods: We conducted a retrospective study of patients who underwent ankle-brachial index testing (ABI) from 1996 - 2020 at Mayo Clinic. We included patients with PAD defined by abnormal ABI (<1.0 or >/=1.4). Primary outcomes evaluated were myocardial infarcts (MI), ischemic strokes (IS), critical limb ischemia (CLI)/amputation, bleeding events and all-cause mortality. DOAC and warfarin use were each compared to no anticoagulant use for the outcomes using univariate analysis and multivariate analysis. Results: 22,162 patients had abnormal ABI readings; 1,266 were on warfarin and 269 were on DOAC for any indication. Both the DOAC and warfarin groups showed significant a decrease in all-cause mortality. The DOAC group showed superior mortality outcomes with HR 0.50 [95% CI 0.40-0.63], p-value <0.001 compared to warfarin with HR 0.88 [95% CI 0.81-0.96], p-value <0.004. There appeared to be a similar trend for MI and CLI/amputation however this was not statistically significant. IS was similar with only warfarin being statistically significant. The DOAC group had improved bleeding outcomes compared to the warfarin group, HR 0.53 (95% CI 0.24-0.85), p-value 0.007. Notably, the addition of ASA for both AC groups resulted in significant HR >1. Conclusions: Our study shows that anticoagulation use, particularly DOACs, is associated with decreased all-cause mortality in patients with PAD. There appears to be a favorable trend for DOACs in MI, IS and CLI/amputation. Lastly, DOACs were found to have superior outcomes with bleeding events.

Exercise oximetry in clinical practice: A single-centre perspective on procedure and techniques

In moderate lower extremity artery disease (LEAD), when tissue ischaemia due to impaired inflow occurs at exercise but not during rest, exercise oximetry may be evaluated as a part of the diagnosis process. Initially used when assessing critical limb ischaemia at rest, transcutaneous oximetry (TcpO2) has also been used in the last two decades during exercise assessment as a non-invasive method to measure oxygen pressure at the skin's surface, offering insights into loco-regional oxygen delivery-requirement mismatch. The introduction of decrease from rest of oxygen pressure (DROP) analysis in the TcpO2 technique, which corresponds to the difference between limb oxygen pressure changes and chest oxygen pressure changes from rest, provides new information about the severity of the local ischaemia during exercise. In this paper, we elucidate the utilization of TcpO2 during exercises (Ex-TcpO2) over the years and provide information about how the technique has evolved and how the changes in the testing procedures have provided the opportunity for detecting abnormalities in both vascular and non-vascular clinical practice. We discuss the importance of Ex-TcpO2 in the diagnosis of peripheral artery disease and its valuable contribution as a differential diagnostic tool for patients with co-morbid conditions such as lumbar spinal stenosis. We also provide recommendations about the utilization of Ex-TcpO2 and contribute to a better understanding of the techniques in terms of efficacy, limitations and clinical applications. However, clarifications about its role in the diagnostic algorithm are needed, to ensure a better integration of the technique in clinical practice.

Ankle-Brachial Index and Risk of Sudden Cardiac Death in the Community: The ARIC Study

BACKGROUND

Sudden cardiac death (SCD) is a significant global public health problem accounting for 15% to 20% of all deaths. A great majority of SCD is associated with coronary heart disease, which may first be detected at autopsy. The ankle-brachial index (ABI) is a simple, noninvasive measure of subclinical atherosclerosis. The purpose of this study was to examine the relationship between ABI and SCD in a middle-aged biracial general population.

METHODS AND RESULTS

Participants of the ARIC (Atherosclerosis Risk in Communities) study with an ABI measurement between 1987 and 1989 were included. ABI was categorized as low (≤0.90), borderline (0.90-1.00), normal (1.00-1.40), and noncompressible (>1.40). SCD was defined as a sudden pulseless condition presumed to be caused by a ventricular tachyarrhythmia in a previously stable individual and was adjudicated by a committee of cardiac electrophysiologists, cardiologists, and internists. Cox proportional hazards models were used to evaluate the associations between baseline ABI and incident SCD. Of the 15 081 participants followed for a median of 23.5 years, 556 (3.7%) developed SCD (1.96 cases per 1000 person-years). Low and borderline ABIs were associated with an increased risk of SCD (demographically adjusted hazard ratios [HRs], 2.27 [95% CI, 1.64-3.14] and 1.52 [95% CI, 1.17-1.96], respectively) compared with normal ABI. The association between low ABI and SCD remained significant after adjustment for traditional cardiovascular risk factors (HR, 1.63 [95% CI, 1.15-2.32]).

CONCLUSIONS

Low ABI is independently associated with an increased risk of SCD in a middle-aged biracial general population. ABI could be incorporated into future SCD risk prediction models.

A high burden of diabetes and ankle brachial index abnormalities exists in Mexican Americans in South Texas

Ethnic differences exist in the United States in the interrelated problems of diabetes (DM), peripheral arterial disease (PAD), and leg amputations. The purpose of this study was to determine the prevalence and risk factor associations for subclinical PAD in a population sample of Mexican Americans using the ankle brachial (ABI) index. The ABI-High (higher of the two ankle pressures/highest brachial pressure) and ABI-Low (lower of the two ankle pressures/highest brachial pressure) were calculated to define PAD. Toe brachial index (TBI) was also calculated. 746 participants were included with an age of 53.4 ± 0.9 years, 28.3 % had diabetes mellitus (DM), 12.6 % were smokers, and 51.2 % had hypertension (HTN). Using ABI-High ≤ 0.9, the prevalence of PAD was 2.7 %. This rose to 12.7 % when an ABI-Low ≤ 0.9 was used; 4.0 % of the population had an ABI-High > 1.4. The prevalence of TBI < 0.7 was 3.9 %. DM was a significant risk factor for ABI-High ≤ 0.9 and ABI-High > 1.4, and TBI < 0.7. Increased age, HTN, smoking was associated with ABI-High ≤ 0.9, while being male was associated with ABI-High > 1.4. Increased age, smoking, and lower education were all associated with abnormal TBI. Despite relatively younger mean age than other studied Hispanic cohorts, the present population has a high burden of ABI abnormalities. DM was a consistent risk factor for PAD. These abnormalities indicate an important underlying substrate of vascular and metabolic disease that may predispose this population to the development of symptomatic PAD and incident amputations.

Incompressible ankle arteries predict increased morbidity and mortality in patients with an elevated ankle brachial index

OBJECTIVES

Patients with an elevated ankle brachial index (ABI) > 1.3 have a high burden of disease and poorer outcome compared to patients with a lower ABI. Previously differences between patients with ABI > 1.3 have not been studied in detail. The aim of this study was to analyze the morbidity and mortality of patients with ABI > 1.3.

METHODS

ABI measurements were performed in the vascular laboratory of Turku university hospital 2011-2013. Patients with ABI>1.3 in at least one lower limb were included in the study and divided into 3 groups: At least one lower limb ABI 1.3-2.5 but both limbs <2.5 (group 1), one limb ABI ≥2.5 (group 2), both limbs ABI ≥ 2.5 (group 3).

RESULTS

534 patients were included in the study. The patients in groups 2 and 3 were more often female (p < .001), older (p < .001), had more diabetes (p = .013), coronary artery disease (p = .001) and chronic heart (p = .010) and kidney failure (p = .013) compared to patients in group 1. The survival of patients in group 2 and 3 was significantly poorer compared to the patients in group 1 (HR1.6, 95% CI 1.2-2.2, p = .002 and 1.7, 95% CI 1.2-2.3, p < .001, respectively). Overall and cardiovascular mortality was higher in groups 2 and 3 than group 1.39.5% of patients with incompressible ankle arteries (ABI ≥ 2.5) in both lower limbs had toe pressure (TP) <50 mmHg and a poorer survival compared to patients with a higher TP.

CONCLUSIONS

Patients with incompressible ankle arteries have significantly higher overall and cardiovascular mortality and a greater burden of disease compared to the patients with a measurable yet abnormally high ABI. TP is a useful diagnostic tool when ABI is immeasurably high. All patients with ABI > 1.3 should be considered as high cardiovascular risk patients.

Contrast-free ultrasound imaging for blood flow assessment of the lower limb in patients with peripheral arterial disease: a feasibility study

While being a relatively prevalent condition particularly among aging patients, peripheral arterial disease (PAD) of lower extremities commonly goes undetected or misdiagnosed due to its symptoms being nonspecific. Additionally, progression of PAD in the absence of timely intervention can lead to dire consequences. Therefore, development of non-invasive and affordable diagnostic approaches can be highly beneficial in detection and treatment planning for PAD patients. In this study, we present a contrast-free ultrasound-based quantitative blood flow imaging technique for PAD diagnosis. The method involves monitoring the variations of blood flow in the calf muscle in response to thigh-pressure-cuff-induced occlusion. Four quantitative metrics are introduced for analysis of these variations. These metrics include post-occlusion to baseline flow intensity variation (PBFIV), total response region (TRR), Lag0 response region (L0RR), and Lag4 (and more) response region (L4 + RR). We examine the feasibility of this method through an in vivo study consisting of 14 PAD patients with abnormal ankle-brachial index (ABI) and 8 healthy volunteers. Ultrasound data acquired from 13 legs in the patient group and 13 legs in the healthy group are analyzed. Out of the four utilized metrics, three exhibited significantly different distributions between the two groups (p-value < 0.05). More specifically, p-values of 0.0015 for PBFIV, 0.0183 for TRR, and 0.0048 for L0RR were obtained. The results of this feasibility study indicate the diagnostic potential of the proposed method for the detection of PAD.

Low and High Ankle-Brachial Index Are Both Associated with Mortality in German Nursing Home Residents-The Five-Year Follow-Up of the "Allo-Study" Cohort

Peripheral arterial disease (PAD) is associated with high cardiovascular morbidity and mortality. We aimed to examine this relation in a population that tends to be under-represented in research on the topic. In a prospective observational cohort study, residents of 45 nursing homes in Germany were screened for pathological ankle-brachial index (ABI) and observed for five years. Of 1333 participants (median age 84 years), 55.5% had a pathological ABI (≤0.9 or >1.4) on one or both legs. 84.7% of the probands with a low ABI (indicating PAD) had no previously known PAD diagnosis. The five-year mortality was 73.0%. Mortality was higher in individuals with a pathological ABI (76.5%) than in those with a normal ABI (68.7%, p = 0.003). An ABI > 1.4 was associated with a higher mortality (79.4%) than a reduced (74.7%) or normal ABI (68.7%, p = 0.011). Pathological ABI values were associated with an increase in mortality after correction for age, sex and all recorded comorbidities, including cardiac disease. Although PAD is highly prevalent in nursing home residents, it is underdiagnosed and undertreated. In the study cohort, both high and low ABI were important predictors of mortality. PAD deserves more attention in this high-risk population.

Peripheral arterial disease: A small and large vessel problem

Peripheral arterial disease (PAD) is one clinical manifestation of systemic atherosclerosis and is very common. Despite its prevalence, PAD remains underdiagnosed, undertreated, and understudied. The most common symptom in patients with PAD is intermittent claudication (IC), or pain in the lower extremities with walking or exertion, which is relieved after a short period of rest. Many patients with confirmed PAD are asymptomatic or have symptoms other than IC. Regardless of symptoms, patients with PAD have poor cardiovascular outcomes. PAD has largely been viewed a disease of large vessel atherosclerosis but what is becoming clear is that arterial plaques and occlusions are only one piece of the puzzle. Recent work has shown that abnormalities in the microvasculature contribute to the outcome of patients with PAD. From the perspective of the leg, limitation in blood flow is not the only problem as patients have a myriad of other problems, including muscle fibrosis, neuropathic changes, changes in the cellular respiration machinery and dysfunction of the small vessels that perfuse skeletal muscle and the supporting structures. Supervised exercise training remains one of the most effective tool to treat patients with PAD, however, the mechanisms behind its effectiveness are still being elucidated and use of structured exercise programs is not widespread. Medical therapy to treat systemic atherosclerosis is underutilized in patients with PAD. Invasive therapies are used only when patients with PAD have reached an advanced stage. While invasive strategies are effective in some patients with PAD, these strategies are costly, carry risk, and many patients are not amenable to invasive therapy. Appreciating the complex pathophysiology of PAD will hopefully spur new research and development of effective therapies for PAD.

Predictive Value of the Ankle-Brachial Index for All-Cause and Cardio-Cerebrovascular Mortality

The present study explored the relationship between the ankle-brachial index (ABI) (>.9) and all-cause or cardio-cerebrovascular mortality. Participant details were obtained from the National Health and Nutrition Examination Survey 1999-2004. The association between baseline ABI and the risk of mortality was evaluated by a priori defined quartile categories and on a continuous scale (per .1-unit change) with Cox regression models adjusted for demographic and traditional risk factors. A total of 7087 individuals (age: 59.6 ± 12.8 years) were included; 3612 (51.0%) were male. After an average follow-up of 12.2 years, 1926 deaths occurred. Kaplan-Meier analysis showed that the lowest ABI quartile (<1.06) was associated with the highest risk of all-cause, cardio-cerebrovascular and cancer mortality (all P < .001). However, after adjusting for potential confounders, ABI ranging between 1.06 and 1.12 was associated with the lowest risk of all-cause mortality (hazard ratio .88, 95% confidence interval .78-1.00, P < .05) compared with the reference group (<1.06). Besides, splines showed the relationship was nonlinear (P < .05) and the inflection point was 1.11. In conclusion, the level of ABI associated with the lowest risk of all-cause mortality was 1.11, under which a lower ABI was independently associated with an increased risk of all-cause mortality.

Abnormal Calcium Metabolism Mediated Increased Risk of Cardiovascular Events Estimated by High Ankle-Brachial Index in Patients on Peritoneal Dialysis

Cardiovascular disease (CVD) is the leading cause of death in peritoneal dialysis (PD) patients. But the relationship between regular PD and the risk of major adverse cardiovascular events (MACE) remains controversial. The possible risk factors are not fully elucidated. This study aims to investigate the possible factors affecting the risk of MACE estimated by high ankle-brachial index (ABI) in PD patients. A total of 243 patients were enrolled and divided into chronic kidney diseases (CKD) stage 1, non-dialyzed CKD stages 2–5, and PD groups. The prevalence of high ABI, indicating increased MACE, was elevated with CKD progression but not further increased in PD patients. Systolic blood pressure was closely correlated with high ABI in non-dialyzed CKD patients (β = 0.059, P = 0.001). But in PD patients, serum calcium had a crucial effect on high ABI (β = −9.853, P < 0.001). Additionally, PD patients with high ABI tended to dialyze inadequately (Kt/V <1.7) compared to those with normal ABI (29.0 vs. 13.3%, P = 0.031). Further mediation analysis revealed that ~86.2% of the relationship between Kt/V and high ABI was mediated by serum calcium in PD patients (mediation effect = 86.2%, ab = −0.220, 95% CI: −0.381 to −0.059, P = 0.008), especially in those starting PD before 55 years of age and with normal body mass index. This present study indicated that improvement of PD adequacy by maintaining calcium balance might be a promising method to reduce the risk of MACE estimated by high ABI for PD patients.

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.

Disparity in association of obesity measures with ankle and brachial systolic blood pressures in Europeans and South Asians

Obesity causes increases in brachial systolic-blood-pressures (SBP), risks of type 2 diabetes (T2DM) and cardiovascular diseases (CVD). Brachial and ankle SBPs have differential relationship with T2DM and CVD. Our objective was to study the relationship of obesity measures with brachial and ankle SBPs. A population of 1098 adults (South Asians n = 699; 41.70% male and 58.3% female) were recruited over 5 years from primary care practices in England. Their four limbs SBPs were measured using Doppler machine and body-mass-index (BMI) and waist-to-height-ratio (WHtR) calculated. Linear regressions were performed between SBPs and obesity measures, after adjustments for sex, age, ethnicity, T2DM and CVD. The mean age of all participants was 51.3 (SD = 17.2), European was 57.7 (SD 17.2) and South Asian was 47.8 (SD = 16.1). The left posterior tibial [Beta = 1.179, P = 4.559 × 10⁻¹⁵] and the right posterior tibial SBP [Beta = 1.178, P = 1.114 × 10⁻¹³] most significantly associated with the BMI. In South Asians, although the left brachial [Beta = 25.775, P = 0.032] and right brachial SBP [Beta = 22.792, P = 0.045] were associated to the WHtR, the left posterior tibial SBP [Beta = 39.894, P = 0.023], association was the strongest. For the first time, we have demonstrated that ankle SBPs had significant association with generalised obesity than brachial systolic blood pressures (SBP), irrespective of ethnicity. However, with respect to visceral obesity, the association with ankle SBP was more significant in South Asians compared to Europeans.

Screen-detected abnormal ankle brachial index: A risk indicator for future cardiovascular morbidity and mortality in patients with manifest cardiovascular disease

Objectives

The ankle brachial index (ABI) can be used to diagnose peripheral arterial disease (PAD). The clinical relevance of the ABI, especially in patients with known clinically manifest cardiovascular disease (CVD), is unknown. The authors set out to investigate the relationship between a screen-detected ABI and the risk for future cardiovascular morbidity and mortality in patients with clinically manifest CVD.

Design, materials and methods

Patients with clinically manifest CVD were selected from the UCC-SMART cohort (n = 8360) and divided into four groups: normal ABI (0.91–1.39), screen-detected low ABI ≤ 0.9, screen-detected high ABI ≥ 1.4, and patients with known PAD irrespective of their ABI. Adjusted Cox Proportional Hazard Ratios (HRs) for Major Adverse Cardiovascular Events (MACE), Major Adverse Limb Events (MALE), and all-cause mortality were calculated. In addition, stratified analyses for women and men and for the presence of diabetes were performed.

Results

During a median follow-up of 8.3 years (IQR 7.7) 1646 MACE, 601 MALE and 1958 all-cause mortalities were observed. Compared with normal ABI patients, patients with a screen-detected low ABI and patients with manifest PAD had a higher risk of MACE, MALE, and all-cause mortality with HRs of 1.9 (95% CI 1.6–2.2) for MACE, 7.6 (95% CI 5.7–10.1) for MALE, 1.7 (95% CI 1.5–2.0) for mortality and 1.3 (95% CI 1.2–1.5) for MACE, 13.8 (95% CI 11.1–17.1) for MALE, 1.7 (95% CI 1.5–1.9) for mortality, respectively. Screen-detected high ABI did not increase the risk of either MACE or MALE, however, was associated with lower risk of all-cause mortality with a HR of 0.6 (95% CI 0.5–0.9). Stratified analyses for women & men and for diabetes status were comparable for all three outcomes.

Conclusions

In patients with manifest CVD but without PAD, a screen-detected low ABI is a powerful risk indicator for cardiovascular events, limb events, and all-cause mortality.

Protocol of the Inner Mongolian Healthy Aging Study (IMAGINS): a longitudinal cohort study

BACKGROUND

Cardiovascular diseases (CVDs) remain the leading cause of premature mortality and burden of diseases in the world. The Inner Mongolia Autonomous Region is located in northern China, constitute 17.66% individuals with Mongolian, which have unique diet and lifestyles. Therefore, the Inner Mongolian Healthy Aging Study (IMAGINS) was designed to explore risk factors for chronic diseases and evaluate the effectiveness of health management on CVDs in population at high-risk.

METHODS

The IMAGINS is an ongoing and prospective cohort study of men and women aged ≥35 years from Inner Mongolian Autonomous Region, northern China. This study performed in investigating risk factors for CVDs, screening and providing health management strategy for high-risk population of CVDs. The IMAGINS began in September 2015 and scheduled to recruiting and follow-up outcome until 2030. For general population, a long-term follow-up will be conducted every 5 years to collect the information above and data on clinical outcomes. For high-risk population, comprehensive health managements were performed and scheduled to follow-up annually. All IMAGINS participants are followed for incident CVDs and death.

DISCUSSION

The IMAGINS is designed to increase understanding how cardiovascular-related risk factors contribute to the development of CVDs and the positive effect of health management strategy for high-risk CVD participants. Key features of this study include (i) a carefully characterized cohort between high risk of CVDs and non-high risk population; (ii) detailed measurement of CVDs risk factors and health management strategies for high risk population; (iii) long-term follow-up of CVDs and death. The IMAGINS represents a good research opportunity to investigate clinical and genetic factors in high-risk population, might providing basis for the prevention and control of non-communicable diseases.

Associations of lower-limb atherosclerosis and arteriosclerosis with cardiovascular risk factors and disease in older adults: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND & AIMS

Atherosclerosis and arteriosclerosis contribute to vascular aging and cardiovascular disease (CVD) risk. Both processes can be assessed simply in the lower-limbs and reflect systemic pathology. However, only atherosclerosis is routinely assessed, typically via ankle-brachial index (ABI). Arteriosclerosis can be assessed using femoral-ankle pulse wave velocity (faPWV), but no studies have identified whether ABI and faPWV similarly associate with overt CVD and risk factors, nor whether faPWV confers additional information. The aims of this study were to (i) compare associations of ABI and faPWV with traditional CVD risk factors, including age, sex, systolic blood pressure (SBP), high-density lipoprotein (HDL), total cholesterol (TC), smoking, and diabetes; and (ii) determine the independent and additive associations of ABI and faPWV with a composite measure of prevalent CVD.

METHODS

We evaluated ABI and faPWV in 4330 older-aged (75.3 ± 5.0 years) adults using an oscillometric screening device. Associations between ABI and faPWV with CVD risk factors and CVD were determined using mixed-model linear- and logistic-regression.

RESULTS

ABI and faPWV were associated with age, HDL, and smoking. ABI was associated with sex, TC, diabetes. faPWV was associated with SBP. Both ABI and faPWV were inversely associated with CVD. Low ABI (≤0.9 vs. >0.9) and low faPWV (≤9.94 vs. >9.94) increased the odds of CVD by 2.41-fold (95% CI:1.85,3.17) and 1.46-fold (95% CI:1.23,1.74), respectively. The inverse association between faPWV and CVD was independent of ABI and CVD risk factors.

CONCLUSIONS

ABI and faPWV, measures of lower-limb atherosclerosis and arteriosclerosis, are independently associated with CVD risk factors and prevalent CVD. Assessment of faPWV may confer additional risk information beyond ABI.

Cold Pressor Test Influences the Cardio-Ankle Vascular Index in Healthy Overweight Young Adults

Objective

The cold pressor test (CPT) has been shown a potential sympathoexcitatory stimulus which increases aortic pulse wave velocity and the aortic augmentation index, suggesting that noninvasively, arterial stiffness parameters are altered by the CPT. The cardio-ankle vascular index (CAVI) is widely used for reflecting arterial stiffness, and the ankle-brachial index (ABI) for evaluating peripheral artery disease in obesity. We aimed to assess CAVI and ABI in overweight young adults in the context of sympathetic activation by using the CPT.

Methods

160 participants were divided into 2 groups: 86 normal-weight (body mass index [BMI] 18.50-22.99 kg/m²) and 74 overweight (BMI ≥23 kg/m²). The CPT was performed by immersing a participant's left hand into cold water (3-5°C) for 3 min, and CAVI and ABI assessment.

Results

At baseline, the CAVI in the overweight group was significantly less than that in the normal-weight group (5.79 ± 0.85 vs. 6.10 ± 0.85; p < 0.05). The mean arterial pressure (MAP) for overweight was significantly greater than that for normal-weight subjects (93.89 ± 7.31 vs. 91.10 ± 6.72; p < 0.05). During the CPT, the CAVI increased in both normal-weight and overweight subjects, the CAVI value was greater during the CPT in overweight subjects by 14.36% (6.62 ± 0.95 vs. 5.79 ± 0.85, p < 0.05) and in normal-weight subjects by 8.03% (6.59 ± 1.20 vs. 6.10 ± 0.85, p < 0.05) than those baseline values. The CPT evoked an increase in systolic blood pressure (SBP), diastolic BP (DBP), heart rate (HR,) and pulse pressure (PP) in both groups. After a 4-min CPT period, the CAVI returned values similar to the baseline values in both groups, and the SBP, DBP, MAP, and PP in overweight participants were significantly higher than those in normal-weight participants. However, there was no significant difference in the ABI at baseline, during CPT, and post-CPT in either group.

Conclusions

Our results indicated that the CAVI was influenced by sympathetic activation response to the CPT in both normal-weight and overweight young adults. Specifically, during the CPT, the percentage change of the CAVI in overweight response was greater in normal-weight participants than baseline values in each group. The ABI was not found significantly associated with CPT. These findings suggesting that sympathoexcitatory stimulus by CPT influence CAVI results.

Ankle-brachial index predicts renal outcomes and all-cause mortality in high cardiovascular risk population: a nationwide prospective cohort study in CORE project

BACKGROUND

Low ankle-brachial index (ABI) related ischemic events are common among individuals with chronic kidney disease (CKD). It is also associated with an increased risk of rapid renal function decline. The presence of peripheral artery disease (PAD) with low ABI among patients with high cardiovascular (CV) risk increases limb loss and mortality.

AIMS

To estimate the association between abnormal ABI and renal endpoints and all-cause mortality.

METHODS

A multicenter prospective cohort study was conducted among subjects with high CV risk or established CV diseases in Thailand. The subjects were divided into 3 groups based on ABI at baseline > 1.3, 0.91-1.3, and ≤ 0.9, respectively. Primary composite outcome consisted of estimated glomerular filtration rate (eGFR) decline over 40%, eGFR less than 15 mL/min/1.73 m², doubling of serum creatinine and initiation of dialysis. The secondary outcome was all-cause mortality. Cox regression analysis and Kaplan-Meier curve were performed.

RESULTS

A total of 5543 subjects (3005 men and 2538 women) were included. Cox proportional hazards model showed a significant relationship of low ABI (ABI ≤ 0.9) and primary composite outcome and all-cause mortality. Compared with the normal ABI group (ABI 0.91-1.3), subjects with low ABI at baseline significantly had 1.42-fold (95% CI 1.02-1.97) and 2.03-fold (95% CI 1.32-3.13) risk for the primary composite outcome and all-cause mortality, respectively, after adjusting for variable factors.

CONCLUSION

Our study suggested that PAD independently predicts the incidence of renal progression and all-cause mortality among Thai patients with high CV risk.

Disparate effects of ankle-brachial index on mortality in the 'very old' and 'younger old' populations-the PolSenior survey

To assess the relationship between ankle-brachial index (ABI) and up to 10-year mortality in older individuals below and above the age of 80 years. In a multicenter survey of health status in the community dwelling subjects aged 55-59 and 65 + years in Poland, we assessed baseline medical history including risk-factors. We measured ABI, and serum creatinine, cholesterol, NT-proBNP, and interleukin-6 (IL-6) concentrations. We assessed mortality based on public registry. Between 2009 and 2019, 27.3% of 561 participants < 80 years, and 79.4% of 291 participants ≥ 80 years, died (p < 0.001); 67.8, 41.5, and 40.3% in the ABI groups < 0.9, 0.9-1.4, and > 1.4, respectively (p < 0.01). In the unadjusted Cox models, ABI was associated with mortality in the entire group, and < 80 years. In the entire group, analysis adjusted for age and sex showed mortality risk increased by 11% per year, and 50% with male sex. Mortality decreased by 37% per 1 unit ABI increase. In the group of people ≥ 80 years, only age was significantly associated with mortality (p < 0.001). In stepwise regression ABI < 0.9, male sex, active smoking, and NT-proBNP level were associated with risk of death < 80 years. In the ≥ 80 years old, mortality risk was associated with older age, and higher levels of IL-6, but not ABI. The ABI < 0.9 is associated with higher mortality in older people, but not among the oldest-old. In the oldest age group, age is the strongest predictor of death. In this age group, inflammageing is of importance.

An elevated ankle-brachial index is not a valid proxy for peripheral medial arterial calcification

BACKGROUND AND AIMS

The ankle brachial index (ABI) is often used as a proxy for medial arterial calcification (MAC) in studies investigating MAC as a cardiovascular risk factor, but evidence supporting this hypothesis is sparse. This study aims to investigate the use of an elevated ABI as proxy for MAC, as visualized with computed tomography (CT).

METHODS

Cross-sectional data of 718 participants with, or at risk of cardiovascular disease was used. The ABI was calculated using cutoffs >1.4 and > 1.3. The presence of MAC was assessed in the crural and femoral arteries by CT imaging. Modified Poisson regression was used to assess the association between an elevated ABI and the presence of MAC, and test characteristics were calculated.

RESULTS

MAC was found in 25.0% of participants. An ABI >1.4 was found in 8.7% of participants, of whom 45.2% had MAC. An elevated ABI was significantly associated with the presence of MAC (RR 1.74, CI: 1.26-2.40). However, poor positive specific agreement (23.3%, CI: 13.9-34.3), sensitivity (15.7%, CI: 10.4-21.1) and positive predictive value (45.2%, CI: 32.8-57.5) were found. Despite good specificity (93.6%, CI: 91.6-95.7) the area under the receiving operator curve remained poor (54.7%, CI: 51.8-57.6). Negative specific agreement (84.5%, CI: 81.4-87.0) and negative predictive value (77.0%, CI: 73.7-80.2) were acceptable.

CONCLUSIONS

An elevated ABI is insufficient to serve as a true diagnostic proxy for MAC. Studies that have drawn conclusions on the association between MAC and cardiovascular disease, solely based on the ABI, are likely to underestimate the found effects.

Abnormal vascular physiology in the lower extremities as a risk factor for ischemic stroke and mortality

CONTEXT

Peripheral artery disease (PAD) is highly prevalent in the general population, affecting up to 25% of patients 55 years of age or older. There is a known association with acute ischemic stroke, but limited large cohort studies exist pertaining to the relationship between PAD severity and incident ischemic stroke.

OBJECTIVES

To evaluate the risk of incident ischemic stroke and mortality along the spectrum of low and elevated ankle brachial index (ABI) measurement.

METHODS

We performed a retrospective extraction of ABI data of all adult patients who underwent lower extremity physiology study for any indication from January 1, 1996 to June 30, 2018 in the Mayo Clinic health system. PAD was categorized into severe, moderate, mild, and borderline based on ABI measurements and poorly compressible arteries (PCA). These were compared with normal ABI measurements. Associations of PAD/PCA with new ischemic stroke events and all cause mortality were analyzed. Hazard ratios (HR) were calculated using multivariable Cox proportional regression with 95% confidence intervals.

RESULTS

A total of 39,834 unique patients were included with a median follow up duration of 4.59 years. All abnormal ABI groups, except borderline PAD, were associated with increased risk of incident ischemic stroke after multivariate regression compared to normal ABI. A severity-dependent association was observed between PAD and ischemic stroke with moderate (HR, 1.22 [95% CI, 1.10-1.35]) and severe (HR, 1.19 [95% CI, 1.02-1.40]) categories conferring similar risk in comparison to normal ABI. Patients with PCA carried the greatest ischemic stroke risk (HR, 1.30 [95% CI, 1.15-1.46]). Similarly, abnormal ABI groups were associated with a significant risk for all cause mortality in a severity-dependent manner, with severe PAD conferring the greatest risk (HR, 3.07 [95% CI, 2.88-3.27]).

CONCLUSIONS

This study adds to the growing body of evidence that both PAD and PCA are independent risk factors for incident ischemic stroke and all cause mortality. The association of PAD severity and PCA with risk of ischemic stroke may help clinicians with risk stratification and determining treatment intensity.

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

Ankle-brachial pressure index (ABPI) is commonly measured in people referred to vascular specialists. This study aimed to assess the association of high ABPI (≥ 1.4) with cardiovascular events in people with peripheral artery disease (PAD). 1533 participants with PAD diagnosed by a vascular specialist were prospectively recruited from four out-patient clinics in Australia. ABPI was measured at recruitment and the occurrence of myocardial infarction (MI), stroke or cardiovascular death (major cardiovascular events; MACE) and any amputation were recorded over a median (inter-quartile range) follow-up of 3.3 (1.0-7.1) years. The association of high, compared to normal, low (0.5-0.9) or very low (<0.5), ABPI with clinical events was estimated using Cox proportional hazard analyses, adjusting for traditional risk factors and reported as hazard ratio with 95% confidence intervals. 596 (38.9%), 676 (44.1%), 157 (10.2%) and 104 (6.8%) participants had normal, low, very low and high ABPI, respectively. Participants with high ABPI had increased risk of MACE, MI and death by comparison to those with either normal ABPI [1.69 (1.07, 2.65), 1.93 (1.07, 3.46) and 1.67 (1.09, 2.56)] or either low or very low ABPI [1.51 (1.02, 2.23), 1.92 (1.16, 3.19) and 1.47 (1.02, 2.14)] after adjusting for other risk factors. Findings were similar in a sensitivity analysis excluding people with ABPI only measured in one leg (n = 120). Participants with high ABPI also had an increased risk of MACE and MI compared to those with very low ABPI alone. High ABPI is a strong indicator of excess risk of cardiovascular events amongst people with PAD.

Associations of Serum Calciprotein Particle Size and Transformation Time With Arterial Calcification, Arterial Stiffness, and Mortality in Incident Hemodialysis Patients

RATIONALE & OBJECTIVE

Characteristics of the transformation of primary to secondary calciprotein particles (CPPs) in serum, including the size of secondary CPP (CPP2) aggregates and the time of transformation (T₅₀), may be markers for arterial calcification in patients undergoing hemodialysis (HD). We examined the associations of CPP2 aggregate size and T₅₀ with arterial calcification in incident HD patients.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Incident HD patients (n=402with available CPP2 measures and n=388with available T₅₀ measures) from the Predictors of Arrhythmic and Cardiovascular Risk in End-Stage Renal Disease (PACE) Study PREDICTORS: Serum CPP2 size and T₅₀ at baseline.

OUTCOMES

Primary outcomes were baseline coronary artery and thoracic aorta calcifications. Exploratory outcomes included baseline arterial stiffness, measured by pulse wave velocity (PWV) and ankle brachial index, and longitudinally, repeat measures of PWV and all-cause mortality.

ANALYTICAL APPROACH

Tobit regression, multiple linear regression, Poisson regression, linear mixed-effects regression, and Cox proportional hazards regression.

RESULTS

Mean age was 55±13 years, 41% were women, 71% were Black, and 57% had diabetes mellitus. Baseline CPP2 size and T₅₀ were correlated with baseline fetuin A level (r=-0.59 for CPP2 and 0.44 for T₅₀; P<0.001 for both), but neither was associated with baseline measures of arterial calcification or arterial stiffness. Baseline CPP2 size and T₅₀ were not associated with repeat measures of PWV. During a median follow-up of 3.5 (IQR, 1.7-6.2) years, larger CPP2 was associated with higher risk for mortality (HR, 1.17 [95% CI, 1.05-1.31] per 100nm larger CPP2 size) after adjusting for demographics and comorbid conditions, but there was no association between baseline T₅₀ and risk for mortality.

LIMITATIONS

Possible imprecision in assays, small sample size, limited generalizability to incident HD populations with different racial composition, and residual confounding.

CONCLUSIONS

In incident HD patients, neither CPP2 size nor T₅₀ was associated with prevalent arterial calcification and stiffness. Larger CPP2 was associated with risk for mortality, but this finding needs to be confirmed in future studies.

Development of a 3-Dimensional Prognostic Score for Patients With Symptomatic Peripheral Artery Disease: PAD3D Score

Peripheral artery disease (PAD) is a high-risk condition for cardiovascular (CV) events, but no specific prognosis assessment tool exists. We developed an individual risk score (PAD^3D) based on the combined predictive value for mortality, including (1) age, (2) severity of PAD, and (3) extent of atherosclerosis. Patients (n = 1310) with symptomatic PAD were followed up for a mean of 50 ± 26 months. The cohort was randomly subdivided into a test and validation cohort. All-cause and CV mortality were prospectively analyzed for PAD^3D score and in combination with classical risk factors. For the test and validation cohort (n = 655 each), all-cause and CV mortality were predicted (P < .001) by the PAD^3D score. Additional inclusion of classical risk factors did not increase discrimination compared with PAD^3D as "area under receiver-operating characteristic" curves were similar for both scores at any time point. Thus, the addition of the classical risk factors to PAD^3D did not further improve the prognostic value. The PAD^3D score provides a risk gradient of a 4.5-fold increase in all-cause and CV mortality. We developed a score for precise prediction of all-cause and CV mortality. The PAD^3D score promises to allow for personalized goals in risk intervention.

Hypertension and high ankle brachial index: the overlooked combination

OBJECTIVE

Assessment of asymptomatic organ damage in the management of hypertension includes low (<0.9) ankle brachial index (ABI) values. No recommendations are given for patients with high ABI (≥1.3), despite evidence of an association with increased risk. We aimed to study the association of high ABI with all-cause mortality and cardiovascular outcomes in a hypertensive population.

METHODS

In anonymized clinical records from the Catalan Primary Care (SIDIAP) database, we designed a large cohort of hypertensive patients aged 35-85 years at the start date. Participants were excluded if they had previous heart failure, coronary heart disease, stroke, diabetes mellitus, or chronic kidney disease. The study population was categorized according to ABI values. Cox proportional hazards models were used to assess all-cause mortality, heart failure, acute myocardial infarction, and stroke.

RESULTS

From 2006 through 2015, SIDIAP records included 44 657 hypertensive patients with an ABI measurement 9126 of whom met inclusion criteria. The median follow-up (first to third quartiles) was 6.0 years (4.7-7.6). High ABI (≥ 1.3) was associated with an increase in mortality risk, hazard ratio, and 95% confidence interval: 1.44 (1.10-1.88), similar to the group with ABI at least 0.9 and less than 1.1, hazard ratio 1.36 (1.12-1.65), and lower than all groups with ABI less than 0.9. High ABI values tended to associate with heart failure, hazard ratio 1.34 (0.95-1.91), but the relation of high ABI with acute myocardial infarction and stroke was nonsignificant, hazard ratios 1.30 (0.72-2.35) and 0.97 (0.65-1.42), respectively.

CONCLUSION

Patients with high ABI values and hypertension presented an increased all-cause mortality risk that could be considered when advising such patients.

Relation between high Ankle-Brachial Index and cardiovascular outcomes in the general population and cardiovascular disease: a meta-analysis

INTRODUCTION

Conflicting findings have been reported on the association between high Ankle-Brachial Index (ABI) and cardiovascular outcomes. This meta-analysis aimed to assess the association of abnormally high ABI and cardiovascular outcomes in the general population and suspected or established cardiovascular disease (CVD) patients.

EVIDENCE ACQUISITION

A comprehensive literature search was conducted in PubMed and Embase databases through November 10th, 2018. All observational studies evaluating the association of high ABI with cardiovascular events including stroke, coronary heart disease (CHD), congestive heart failure, and composite of CVD/all-cause mortality in the general population and suspected or established CVD patients were included. We pooled risk ratios (RR) with 95% confidence intervals (CI) for the abnormally high ABI (> 1.3 or >1.4) versus the reference normal ABI category.

EVIDENCE SYNTHESIS

We identified 10 cohort studies enrolling 39,421 participants. A random effect model meta-analysis indicated that the pooled RR of composite of CVD/all-cause mortality was 1.07 (95% CI 0.83-1.38) in the general population and 1.26 (95% CI 1.03-1.55) in suspected or established CVD patients. Moreover, participants with abnormally high ABI did not increase the risk of stroke (RR 1.60; 95% CI 0.83-3.06) and CHD (RR 1.40; 95% CI 0.87-2.24) in the general population.

CONCLUSIONS

Abnormally high ABI appears to be associated with an increased risk of a composite of CVD/all-cause mortality in suspected or established CVD patients but not in the general population. However, additional well-designed studies are required to support the current findings.

Impact of Body Mass Index on the Association of Ankle-Brachial Index With All-Cause and Cardiovascular Mortality: Results from the National Health and Nutrition Examination Survey

OBJECTIVE

To assess the influence of body-mass index (BMI) on the association of ankle-brachial index (ABI) with mortality.

PATIENTS AND METHODS

We conducted a prospective study of National Health and Nutrition Examination Survey participants enrolled from January 1, 1999 to December 31, 2002 with BMI and ABI data available. ABI categories were <0.9 (low), 0.9 to 1.3 (reference), and >1.3 (high). BMI categories were <30 kg/m² (nonobese) and ≥30 kg/m² (obese). Cardiovascular (CV) and all-cause mortality were assessed by National Death Index records. Cox proportional-hazards models and Kaplan-Meier survival estimates were used to compare groups.

RESULTS

In total, 4614 subjects were included, with mean age 56±12 years and BMI 28±6 kg/m². Median follow-up was 10.3 years (interquartile range [IQR]: 9.3 to 11.4 years). Low and high ABI were present in 7% and 8%, respectively. After adjustment, low ABI was associated with increased all-cause and CV mortality in nonobese (hazard ratio [HR] 1.5, 95% CI, 1.1-2.1 for all-cause and 3.0 [1.8-5.1] for CV mortality) and obese individuals (1.8 [1.2-2.7] and 2.5 [1.2-5.6], respectively) compared with reference. High ABI was associated with increased CV mortality in nonobese (2.2 [1.1-4.5]) but not obese patients; it was not associated with all-cause mortality overall or when stratified by BMI.

CONCLUSION

In a US cohort, weight influenced the prognostic significance of high ABI. This may be related to technical factors reducing compressibility of the calf arteries in obese persons compared with those who are nonobese.

Diabetes Mellitus Modifies the Associations of Serum Magnesium Concentration With Arterial Calcification and Stiffness in Incident Hemodialysis Patients

Introduction

Magnesium (Mg) may protect against arterial calcification. We tested the hypotheses that a higher serum Mg concentration is associated with less arterial calcification and stiffness in patients on hemodialysis (HD) and that these associations are modified by diabetes mellitus.

Methods

We performed cross-sectional analyses of 367 incident HD patients from the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease (PACE) cohort. Measures of arterial calcification and stiffness included coronary arterial calcification (CAC) and thoracic aortic calcification (TAC) scores, ankle brachial index (ABI; high ABI: >1.4 or incompressible vessels), pulse wave velocity (PWV), and pulse pressure.

Results

Mean Mg was 1.8 ± 0.2 mEq/l and 58% had diabetes. Among nondiabetic individuals, per 0.1 mEq/l higher Mg, non-zero CAC score was lower (% difference: −15.4%; 95% confidence interval [CI]: −28% to −0.55%; P = 0.03), the odds of having TAC score >0 and the odds of having high ABI were lower (odds ratio [OR]: 0.66; 95% CI 0.47–0.93; P = 0.02, and 0.23; 95% CI: 0.06–0.83, P = 0.03, respectively) while adjusting for demographics, comorbidities, markers of mineral metabolism, and dialysis clearance. Among diabetic individuals, per 0.1 mEq/l higher Mg, the odds of having TAC score >0 was higher (OR: 1.57; 95% CI: 1.09–2.26; P = 0.02). Mg was not associated with CAC or high ABI among diabetic individuals. Mg was not associated with PWV or pulse pressure regardless of diabetes status.

Conclusion

Diabetes modified the associations of serum Mg with arterial calcification and stiffness in incident HD patients. Higher Mg was associated with less arterial calcification and less peripheral arterial stiffness among nondiabetic individuals, but Mg was only associated with TAC among diabetic individuals with higher Mg being associated with higher likelihood of having TAC score >0.

Prognostic impact of the ankle-brachial index on the development of micro- and macrovascular complications in individuals with type 2 diabetes: the Rio de Janeiro Type 2 Diabetes Cohort Study

AIMS/HYPOTHESIS

The prognostic importance of the ankle-brachial index (ABI) in individuals with diabetes is controversial. We aimed to evaluate the relationship between the ABI and the occurrence of micro- and macrovascular complications in individuals with type 2 diabetes.

METHODS

The ABI was measured at baseline in 668 individuals with type 2 diabetes, and the individuals were followed-up for a median of 10 years. Multivariate Cox analysis was used to examine associations between the ABI and the occurrence of microvascular (retinopathy, microalbuminuria, renal function deterioration and peripheral neuropathy) and macrovascular (total cardiovascular events, major adverse cardiovascular events [MACE] and cardiovascular mortality) complications, and all-cause mortality. The improvement in risk stratification was assessed using the C statistic and the integrated discrimination improvement (IDI) index.

RESULTS

During follow-up, 168 individuals had a cardiovascular event (140 MACE) and 191 individuals died (92 cardiovascular deaths); 156 individuals newly developed or experienced worsening diabetic retinopathy, 194 achieved the renal composite outcome (122 with newly developed microalbuminuria and 93 with deteriorating renal function) and 95 newly developed or experienced worsening peripheral neuropathy. The ABI, either analysed as a continuous or as a categorical variable, was significantly associated with all macrovascular and mortality outcomes, except for non-cardiovascular mortality. Individuals with a baseline ABI of ≤0.90 had a 2.1-fold increased risk of all-cause mortality (95% CI 1.3, 3.5; p = 0.004), a 2.7-fold excess risk of cardiovascular mortality (95% CI 1.4, 5.4; p = 0.004) and a 2.5-fold increased risk of MACE (95% CI 1.5, 4.4; p = 0.001). The ABI improved risk discrimination over classical risk factors, with relative IDIs ranging from 6.3% (for all-cause mortality) to 31% (for cardiovascular mortality). In addition, an ABI of ≤0.90 was associated with the development or worsening of peripheral neuropathy (2.1-fold increased risk [95% CI 1.1, 4.3]; p = 0.033), but not with retinopathy or renal outcomes.

CONCLUSIONS/INTERPRETATION

A low ABI is associated with excess risk of adverse cardiovascular outcomes, mortality and peripheral neuropathy development or worsening, and improves cardiovascular risk stratification. The ABI should therefore be routinely evaluated in individuals with type 2 diabetes.

Long-term effects of air pollution on ankle-brachial index

BACKGROUND

Ankle-brachial index (ABI) has been linked to the risk of cardiovascular events. However, the association between long-term exposure to air pollution and abnormal ABI has not been fully investigated.

METHODS

This cross-sectional study involved 4544 participants from the KORA Study (2004-2008) in the region of Augsburg, Germany. Participants' residential annual mean concentrations of particulate matter (PM) and nitrogen dioxide (NO₂) were predicted with land-use regression models, and the traffic information was collected from geographic information systems. We applied multinomial logistic regression models to assess the effects of air pollution on the prevalence of low and high ABI, and quantile regression models to explore the non-monotonic relationship between air pollution and ABI. We also examined effect modification by individual characteristics.

RESULTS

Long-term exposure to PM with an aerodynamic diameter ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5) was significantly associated with a higher prevalence of low ABI, with the respective odds ratios (ORs) of 1.82 (95%CI: 1.11-2.97) and 1.59 (95%CI: 1.01-2.51) for a 5th to 95th percentile increment in pollutants. Positive associations with the prevalence of high ABI were observed for PM (e.g., PM₁₀: OR = 1.63, 95%CI: 1.07-2.50) and NO₂ (OR = 1.84, 95%CI: 1.15-2.94). Quantile regression analyses revealed similar non-monotonic results. The effects of air pollution on having abnormal ABI were stronger in physically inactive, hypertensive, or non-diabetic participants.

CONCLUSIONS

Long-term exposure to PM and NO₂ was associated with a higher prevalence of both low and high ABI, indicating the adverse effects of air pollution on atherosclerosis and arterial stiffness in the lower extremities.

Association of Peripheral Artery Disease With Incident Atrial Fibrillation: The ARIC (Atherosclerosis Risk in Communities) Study

BACKGROUND

Although peripheral artery disease as defined by ankle-brachial index (ABI) is associated with incident atrial fibrillation (AF), questions remain about the risk of AF in borderline ABI (>0.90 to <1.0) or noncompressible arteries (>1.4). We evaluated the association of borderline ABI and ABI >1.4 in the ARIC (Atherosclerosis Risk in Communities) study, a population-based prospective cohort study.

METHODS AND RESULTS

We included 14 794 participants (age, 54.2±5.8 years, 55% women, 26% blacks) with ABI measured at the baseline (1987-1989) and without AF. AF was identified from hospital records, death certificates, and ECGs. Using Cox proportional hazards, we evaluated the association between ABI and AF. During a median follow-up of 23.3 years, there were 2288 AF cases. After adjustment for cardiovascular risk factors, hazard ratio (HR) (95% confidence interval) for AF among individuals with ABI <1.0 compared with ABI 1.0 to 1.4, was 1.13 (1.01-1.27). ABI >1.4 was not associated with increased AF risk. ABI ≤0.9 and borderline ABI were associated with a higher risk of AF compared with ABI 1.0 to 1.4. Demographics-adjusted HRs (95% confidence interval) were 1.43 (1.17-1.75) and 1.32 (1.16-1.50), respectively. However, the associations of ABI ≤0.9 and borderline ABI with AF were attenuated after adjusting for cardiovascular risk factors (HR [95% confidence interval], 1.10 [0.90-1.34] and 1.14 [1.00-1.30]), respectively.

CONCLUSIONS

Peripheral artery disease indicated by low ABI, including borderline ABI, is a weak risk factor for AF. ABI >1.4 is not associated with an increased AF risk. The relationship between peripheral artery disease and AF appears to be mostly explained by traditional atherosclerotic risk factors.

Risk factors for three-vessel coronary artery disease in patients of Northwest Mexico

INTRODUCTION

Three-vessel coronary artery disease is an advanced manifestation of atherosclerosis, with high prevalence in Mexico.

OBJECTIVE

The aim of this study was to describe coronary risk factors in a group of patients with three-vessel coronary artery disease in Northwest Mexico.

METHODS

A cross sectional study was conducted on a population with three-vessel coronary artery disease from May 2015 to February 2016. The disease was defined when ≥70% stenosis was present in each major epicardial coronary artery. Anthropometric and biochemical parameters were measured in each patient. Ankle-Brachial Index was measured with vascular ultrasound, and Syntax score calculation with an on-line application. Statistical analysis for qualitative differences was performed using Pearson X² test, with p<0.05 being considered as significant.

RESULTS

The study included 100 patients, of whom 75 were male (mean age 63±9 years) and 25 female (mean age 69±9 years). The coronary risk factors observed were diabetes (58%), hypertension (86%), smoking (68%), dyslipidaemia (100%), metabolic syndrome (71%), and obesity/overweight (75%). Diabetes and metabolic syndrome prevalence was higher in women (p=0.03), but smoking was higher in men (76%, p=0.003). Ankle-Brachial Index was abnormal in 58% of patients, the mean Syntax score was in 36.9±11.5, and the prevalence of left main coronary heart disease was 36%.

CONCLUSIONS

This group of patients with complex coronary lesions has a high prevalence of coronary risk factors, which could represent a worse prognosis.

Calcification of the splenic, iliac, and breast arteries and risk of all-cause and cardiovascular mortality

BACKGROUND AND AIMS

CVD risks associated with coronary artery calcification (CAC) and aortic calcification (AC) are well known, but less is known about other calcified arteries. We aimed to assess the associations of arterial calcification in the breast, splenic, and internal and external iliac arteries with CVD risk factors and mortality.

METHODS

We conducted a case-cohort study nested in a cohort of 5196 individuals who self-referred or were referred by a health care provider for whole body computed tomography (CT), including a random subcohort (n = 395) and total and CVD mortality cases (n = 298 and n = 90), who died during a median follow-up of 9.4 years. Arterial calcification in the breast, splenic, and internal and external iliac arteries on CT was scored using a simple visual score. AC and CAC were previously measured using the Agatston technique. Logistic regression models were made to study associations of CVD risk factors with calcification in the different vascular beds. Prentice-weighted Cox proportional hazards models adjusted for CVD risk factors, and calcification in other vascular beds, were used to study associations with mortality.

RESULTS

In the subcohort, the mean age was 56.6 years (SD 11.1) and 41.3% were female. The prevalence of calcification on CT, was 11.6% in the splenic, 47.9% in the internal iliac and 9.5% in the external iliac arteries, while 3.7% of women had breast artery calcification (BAC). Calcification in the splenic and iliac arteries was associated with calcification in the abdominal aorta but differentially associated with other CVD risk factors in logistic regression models. The prevalence of BAC was too low to fit these multivariable models. Calcification of the external iliac arteries was significantly associated with both all-cause and CVD mortality, but no longer significant when adjusted for CVD risk factors. Breast artery calcification was associated with both all-cause and CVD mortality independent of CVD risk factors and AAC and CAC (all-cause HR 5.67 [95% CI 1.50-21.41]).

CONCLUSIONS

Risk factors associated with calcification, and the association of calcification with risk of mortality differ across vascular beds, possibly reflecting different pathophysiology.

Lower Extremity Peripheral Arterial Disease Is an Independent Predictor of Coronary Heart Disease and Stroke Risks in Patients with Type 2 Diabetes Mellitus in China

We aimed to determine the relationship between lower extremity peripheral arterial disease (PAD), 10-year coronary heart disease (CHD), and stroke risks in patients with type 2 diabetes (T2DM) using the UKPDS risk engine. We enrolled 1178 hospitalized T2DM patients. The patients were divided into a lower extremity PAD group (ankle-brachial index ≤ 0.9 or >1.4; 88 patients, 7.5%) and a non-PAD group (ankle-brachial index > 0.9 and ≤1.4; 1090 patients, 92.5%). Age; duration of diabetes; systolic blood pressure; the hypertension rate; the use of hypertension drugs, ACEI /ARB, statins; CHD risk; fatal CHD risk; stroke risk; and fatal stroke risk were significantly higher in the PAD group than in the non-PAD group (P < 0.05 for all). Logistic stepwise regression analysis indicated that ABI was an independent predictor of 10-year CHD and stroke risks in T2DM patients. Compared with those in the T2DM non-PAD group, the odds ratios (ORs) for CHD and stroke risk were 3.6 (95% confidence interval (CI), 2.2-6.0; P < 0.001) and 6.9 (95% CI, 4.0-11.8; P < 0.001) in those with lower extremity PAD, respectively. In conclusion, lower extremity PAD increased coronary heart disease and stroke risks in T2DM.

Clinical Characteristics and Outcomes of Patients with High Ankle-Brachial Index from the IMPACT-ABI Study

Background

Reduced ankle–brachial index (ABI) is a predictor of cardiovascular events. However, the significance of high ABI remains poorly understood. This study aimed to assess the characteristics and outcomes of patients with high ABI.

Methods

The IMPACT-ABI study was a retrospective cohort study that enrolled and examined ABI in 3,131 patients hospitalized for cardiovascular disease between January 2005 and December 2012. From this cohort, 2,419 patients were identified and stratified into two groups: high ABI (> 1.4; 2.6%) and normal ABI (1.0–1.4; 97.3%). The primary endpoint was the cumulative incidence of major adverse cardiovascular events (MACE), including cardiovascular-associated death, myocardial infarction, and stroke.

Results

Compared with the normal ABI group, patients in the high ABI group showed significantly lower body mass index (BMI) and hemoglobin level, but had higher incidence of chronic kidney disease and hemodialysis. Multivariate logistic regression analysis revealed that hemodialysis was the strongest predictor of high ABI (odds ratio, 6.18; 95% confidence interval (CI), 3.05–12.52; P < 0.001). During the follow-up (median, 4.7 years), 172 cases of MACE occurred. Cumulative MACE incidence in patients with high ABI was significantly increased compared to that in those with normal ABI (32.5% vs. 14.5%; P = 0.005). In traditional cardiovascular risk factors-adjusted multivariate Cox proportional hazard analysis, high ABI was an independent predictor of MACE (hazard ratio, 2.07; 95% CI, 1.02–4.20; P = 0.044).

Conclusion

Lower BMI, chronic kidney disease, and hemodialysis are more frequent in patients with high ABI. Hemodialysis is the strongest predictor of high ABI. High ABI is a parameter that independently predicts MACE.