Predictive power of novel and established obesity indices for outcome in PAD during a five-year follow-up.

BACKGROUND AND AIMS: Previous data show contradicting results regarding relevance of obesity on outcome in peripheral arterial disease (PAD). Thus, this study aims to evaluate the predictive power of obesity as measured by established and novel obesity indices (waist circumference WC, waist-hip ratio WHR, body-mass index BMI, body adiposity index BAI, visceral adiposity index VAI, weight-adjusted waist index WWI) in a PAD cohort. METHODS AND RESULTS: In 367 patients with diagnosed PAD anthropometric parameters were assessed at study inclusion in an observational study. Mortality data was retrieved from the central death registry after five years. Outcome analyses were performed by multivariable Cox-regression models. 57 PAD patients (15.5%) died during the follow-up, of those 36 were categorized as cardiovascular origin. Patients from the all-cause mortality group were older, more often diabetics with a worse glucose control and had worse renal function. Obesity indices were not significantly different between the event and control group. None of the evaluated risk factors predicted cardiovascular or all-cause death after multivariable adjustment for age, gender, LDL-C, serum creatinine, systolic blood pressure, CRP, smoking habits, diabetes status and previous history of peripheral revascularisation (all-cause WC 1.007 (0.983-1.031), WHR 1.772 (0.106-29.595), BMI 1.006 (0.939-1.078), BAI 1.002 (0.945-1.063), VAI 1.019 (0.895-1.161), WWI 1.085 (0.831-1.416); cv-death WC 1.007 (0.978-1.036), WHR 0.382 (0.006-25.338), BMI 1.004 (0.918-1.098), BAI 1.034 (0.959-1.116), VAI 1.036 (0.885-1.213), WWI 1.061 (0.782-1.441)). CONCLUSION: Obesity as risk marker estimated by indices both for general and visceral adiposity, does not predict mortality in a secondary prevention cohort of PAD patients.

Thrombospondin-4 increases with the severity of peripheral arterial disease and is associated with diabetes.

Thrombospondin-4 (TSP-4) is an extracellular matrix protein of the vessel wall. Despite bench evidence, its significance in the clinical setting of atherosclerosis is missing. TSP-4 (ng/ml) was measured in 365 PAD patientsusing a commercially available ELISA. PAD was diagnosed by the ankle-brachial index (ABI) and clinically graded using the Fontaine classification. TSP-4 levels were significantly higher in Fontaine II vs. Fontaine I (4.78 ± 0. 42, 4.69 ± 0.42, p = 0.043). TSP-4 significantly correlated with ABI (r = - 0.141, p = 0.023, n = 259) after the exclusion of mediasclerotic patients. Binary logistic regression analysis for Fontaine I vs. II showed an OR of 1.70 (1.02-2.82) in a multivariable model adjusted for traditional risk factors. Interestingly, TSP-4 levels were higher in patients with type 2 diabetes mellitus or prediabetes (DGT) compared with normal glucose tolerance (NGT) (4.76 ± 0.42 vs. 4.66 ± 0.41, p = 0.035). ANOVA for PAD and diabetes subgroups showed a linear increase with disease burden with the highest difference between Fontaine I-NGT and Fontaine II-DGT (4.59 ± 0.40, 4.79 ± 0.43, p = 0.015). TSP-4 levels increased with PAD severity and showed a former unknown association with diabetes. Thus, TSP-4 could be a novel marker of atherosclerotic activity, especially in the major subgroup of patients with concomitant diabetes.

Serum Trefoil Factor-3 Predicts Survival in Peripheral Artery Disease.

Trefoil factor 3 (TFF3) has been studied in processes leading to atherosclerosis. Data are scarce in manifest disease and missing in peripheral artery disease (PAD). This study aims to elucidate TFF3 with disease stages, degrees of atherosclerosis, and outcomes. TFF3 was measured in serum in 364 PAD patients without critical limb ischemia and mild to moderate chronic kidney disease (CKD). Mortality data were retrieved from the Austrian central death registry (median observation 9.6 years). Survival analyses were performed using Cox regression and the Kaplan-Meier method. A negative association between ankle-brachial index and TFF3 (P < .001) was observed, while levels were similar in asymptomatic and symptomatic PAD. TFF3 increased with history of cardiovascular and cerebrovascular disease (P < .001). TTF3 was associated with the estimated glomerular filtration rate (R = -0.617, P < .001) and urinary albumin-creatinine ratio (R = 0.229, P < .001). One SD increase in TFF3 showed a worsening in all-cause mortality (hazard ratio 1.68, CI 1.37-2.05) which persisted after multiple adjustment for cardiovascular risk, inflammatory, and angiogenetic markers (hazard ratio 1.35, CI 1.01-1.81). This study is the first to link TFF3 with both disease markers and outcomes in PAD. TFF3 demonstrated associations with renal function, PAD severity measured by ankle-brachial index, and additional atherosclerotic burden in PAD.

Galectin-3 is linked to peripheral artery disease severity, and urinary excretion is associated with long-term mortality.

BACKGROUND AND AIMS: Galectin-3 (Gal-3) is a biomarker involved in fibrosis and vascular inflammation. Gal-3 has been linked to chronic kidney disease (CKD) and patients with peripheral artery disease (PAD). Conflicting reports exist about the relevance of Gal-3 in PAD. The study aims to elucidate a possible link between serum and urinary Gal-3 and long-term survival in PAD patients without critical limb ischemia and mild to moderate CKD. METHODS: Galectin-3 (Gal-3) was measured in serum (n = 311) and urine (n = 266) of PAD patients (age 69 (62-77) years) by bead-based multiplex assay. Urinary Gal-3 concentration was normalized to urine creatinine (cr) levels. Mortality data were retrieved from the Austrian central death registry after a median observation period of 9.2 years. Survival analyses were performed by the Kaplan-Meier method and Cox-regression. RESULTS: Serum Gal-3 was higher in patients with claudication symptoms (p = 0.001) and correlated inversely with the patients' ankle-brachial index (R = -0.168, p = 0.009). Serum Gal-3 and urinary Gal-3 (uGal-3/cr) were associated with the estimated glomerular filtration rate (R = -0.359, p < 0.001; R = -0.285, p < 0.001). Serum Gal-3 was not linked to all-cause mortality [HR 1.17 (CI 0.96-1.42)] over 9.2 years. However, uGal-3/cr was associated with all-cause mortality [HR 1.60 (CI 1.31-1.95)]. This association sustained multivariable adjustment for cardiovascular risk factors and renal function [HR 1.71 (CI 1.35-2.17)]. CONCLUSIONS: This study is the first to show an association of uGal-3/cr and long-term mortality in patients with PAD. Gal-3 was not predictive of long-term mortality but seems to be a marker of PAD severity in patients without critical limb ischemia.

Angiogenin-A Proposed Biomarker for Cardiovascular Disease-Is Not Associated With Long-Term Survival in Patients With Peripheral Artery Disease.

We evaluated angiogenin as a prospective biomarker in peripheral artery disease (PAD) patients with and without claudication symptoms. A pilot study suggested an elevation of angiogenin in critical limb ischemia. However, in PAD patients, the predictive value of angiogenin has not yet been evaluated. For this purpose, 342 patients with PAD (age: 69 ± 10 years, 34.5% women) were followed-up for 7 years in a cross-sectional study. Angiogenin was measured by enzyme-linked immunosorbent assay. All-cause and cardiovascular mortality were analyzed by Cox regression. Angiogenin levels were higher in men (P = .001) and were associated with patient waist-to-hip ratio (P < .001), fasting triglycerides (P = .011), and inversely with estimated glomerular filtration rate (P = .009). However, angiogenin showed no association with age, characteristics of diabetes, markers of lipid metabolism, or C-reactive protein. Angiogenin did not correlate with markers of angiogenesis such as vascular endothelial growth factor, angiopoietin-2, or tie-2. Furthermore, angiogenin was not associated with PAD Fontaine stages or with patient ankle-brachial index in addition to all-cause mortality (hazard ratio [HR] = 1.09 [95% CI: 0.89-1.34]) or cardiovascular morality (HR = 1.05 [0.82-1.35]). These results suggest that angiogenin does not provide further information regarding outcome prediction in patients with PAD.

Evaluation of sCD163 and sTWEAK in patients with stable peripheral arterial disease and association with disease severity as well as long-term mortality.

BACKGROUND AND AIMS: The TNF-superfamily member sTWEAK and its scavenger receptor sCD163 are potentially involved in pathophysiological processes of atherosclerosis. In patients with peripheral arterial disease, previous research has shown that sTWEAK and the sCD163/sTWEAK ratio were independently associated with long term all-cause and cardiovascular survival. Since previous investigations emphasized on symptomatic peripheral arterial disease including critical limb ischemia, this study evaluates sTWEAK and sCD163 in a cohort of stable peripheral arterial disease including asymptomatic (Fontaine stage I) and intermittent claudication (Fontaine stage II) patients. METHODS: sTWEAK concentrations of 354 patients were measured using a commercially available ELISA kit. sCD163 was quantified using a multiplex bead assay. Cox proportional hazards regression was used to assess outcome after a seven-year follow-up. Hazard ratios are given as interquartile range. RESULTS: Patients with intermittent claudication exhibited increased sCD163 levels in comparison to asymptomatic patients (p = 0.002). However, sTWEAK was not related to peripheral arterial disease severity (p = 0.740). A multivariable Cox-proportional hazard models including sTWEAK and cardiovascular risk factors (age, HbA1c, CRP, LDL-C, BMI, eGFR) revealed an inverse association with all-cause mortality (HR 0.775 (95% CI 0.623-0.965) and cardiovascular mortality (HR 0.710 (95% CI 0.534-0.944)). Further multivariable models including sCD163 or the sCD163/sTWEAK ratio and cardiovascular risk factors showed no association with mortality. CONCLUSIONS: This study highlights the use of sCD163 as a novel biomarker for PAD severity and supports sTWEAK as an independent predictor of all-cause and cardiovascular mortality even in stable peripheral arterial disease.

GlycA for long-term outcome in T2DM secondary prevention.

AIMS: Glycosylated acetyls (GlycA), a systemic marker of inflammation, were associated both with incident type 2 diabetes mellitus (T2DM) and incident cardiovascular (CV) disease. This study evaluates the predictive value of GlycA for long-term survival in patients with T2DM and peripheral artery disease (PAD). METHODS: GlycA (mmol/l) levels were measured by nuclear magnetic resonance spectroscopy in a cross-sectional cohort of patients with PAD (n = 319). Both all-cause and CV mortality were evaluated after a follow-up of 9.0 (IQR 6.5-9.5) years. During the follow-up 117 patients died, of those 64 events were of CV origin (PAD-T2DM subgroup: all-cause mortality n = 60, CV-mortality n = 32). RESULTS: PAD-T2DM showed a tendency towards a worse CV risk factor profile and a higher percentage of known coronary artery disease (24.9% vs 43.5%, p < 0.001). GlycA levels were higher in PAD-T2DM (1.6 ± 0.2 vs. 1.53 ± 0.18, p = 0.002). GlycA predicted all-cause mortality after multivariable adjustment for traditional CV risk factors (HR for 1 SD increase 1.51, 95% confidence interval 1.03-2.19) in PAD-T2DM, while no association could be seen with CV-mortality (1.22, 0.73-2.06). CONCLUSIONS: GlycA was capable of predicting long-term outcome in PAD patients with T2DM. Thus, GlycA might reflect the added inflammatory burden of T2DM in systemic atherosclerosis.

Angiopoietin-2 and Survival in Peripheral Artery Disease Patients.

Survival of peripheral arterial disease (PAD) patients increased over the last decade due to increased use of secondary preventive medication and rapid revascularization of PAD patients. Angiogenetic markers such as vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) and its receptor Tie-2 might be useful markers to assess the residual risk for mortality in PAD patients. The aim of this study was to evaluate angiogenetic markers for the prediction of mortality in a PAD cohort. For this purpose, 366 patients (mean age: 69 ± 10 years) with PAD Fontaine stage I or II were included and followed up over a 5-year study period. Serum Ang-2, Tie-2 and VEGF levels were measured by bead-based multiplex assay. All-cause mortality and major cardiovascular events (MACE) including all-cause death, non-fatal stroke and non-fatal myocardial infarction were analysed by Kaplan-Meier and Cox regression analyses after 5 years. Ang-2 was associated with Tie-2 (R = 0.151, p = 0.006) and VEGF levels (R = 0.160, p = 0.002). However, only Ang-2 was linked to all all-cause mortality in PAD patients (hazard ratio [HR]: 1.55 [1.23-2.15], p = 0.008) even after adjustment for age and gender, haemoglobin A1c, low-density lipoprotein cholesterol, systolic blood pressure and glomerular filtration rate (HR: 1.44 [1.03-2.00], p = 0.032). Furthermore, an association of Ang-2 and MACE in PAD patients (HR: 1.36 (1.03-1.78), p = 0.028) was found. This result implies that Ang-2 might be used as an additional marker to stratify PAD patients to predict poor mid-term life expectancy.

YKL-40 levels increase with declining ankle-brachial index and are associated with long-term cardiovascular mortality in peripheral arterial disease patients.

BACKGROUND AND AIMS: YKL-40 is an inflammatory marker secreted by macrophages and is expressed in atherosclerotic plaques. YKL-40 increases in coronary artery disease (CAD) with poor coronary collateral vessel development. Higher levels are linked to reduced survival in CAD patients. Studies evaluating YKL-40 in patients with peripheral arterial disease (PAD) are scarce. This study aims to elucidate a possible link between YKL-40 and PAD severity as well as cardiovascular long-term mortality. METHODS: YKL-40 was measured at baseline in 365 elderly PAD patients (age 69 ±â€¯10.4, 33.7% women, Fontaine stage I-II) by bead-based multiplex assay. Patients were followed for seven years to assess long-term cardiovascular and all-cause survival by Kaplan-Meier and Cox regression. RESULTS: YKL-40 levels were associated with declining ankle-brachial index (ABI) in PAD patients without Moenckeberg's mediasclerosis (R = -0.189, p=0.002). PAD patients with mediasclerosis exhibited higher YKL-40 levels (p=0.002). Baseline YKL-40 levels were significantly associated with cardiovascular mortality (HR 1.52 (1.21-1.91), p < 0.001) and all-cause mortality (HR 1.45 (1.20-1.75), p < 0.001) over a seven-year observation period. After multivariable adjustment for gender, patient age, known carotid artery disease, known coronary artery disease, smoking status, systolic blood pressure, HbA1c, low density lipoprotein cholesterol, estimated glomerular filtration rate, aspartate aminotransferase, and C-reactive protein, YKL-40 remained significantly associated with cardiovascular (HR 1.34 (1.02-1.75), p=0.033) and all-cause mortality (HR 1.25 (1.01-1.55), p=0.039). CONCLUSIONS: Increased YKL-40 levels are independently associated with poor long-term cardiovascular survival in peripheral arterial disease patients. Furthermore, YKL-40 correlates with patients' ABI in PAD in the absence of mediasclerosis.

FABP4 and Cardiovascular Events in Peripheral Arterial Disease.

Fatty acid-binding protein 4 (FABP4) is a possible biomarker of atherosclerosis. We evaluated FABP4 levels, for the first time, in patients with peripheral artery disease (PAD) and the possible association between baseline FABP4 levels and cardiovascular events over time. Patients (n = 327; mean age 69 ± 10 years) with stable PAD were enrolled in this study. Serum FABP4 was measured by bead-based multiplex assay. Cardiovascular events were analyzed by FABP4 tertiles using Kaplan-Meier and Cox regression analyses after 5 years. Serum FABP4 levels showed a significant association with the classical 3-point major adverse cardiovascular event (MACE) end point (including death, nonlethal myocardial infarction, or nonfatal stroke) in patients with PAD ( P = .038). A standard deviation increase of FABP4 resulted in a hazard ratio (HR) of 1.33 (95% confidence interval [95% CI]: 1.03-1.71) for MACE. This association increased (HR: 1.47, 95% CI: 1.03-1.71) after multivariable adjustment ( P = .020). Additionally, in multivariable linear regression analysis, FABP4 was linked to estimated glomerular filtration rate ( P < .001), gender ( P = .005), fasting triglycerides ( P = .048), and body mass index ( P < .001). Circulating FABP4 may be a useful additional biomarker to evaluate patients with stable PAD at risk of major cardiovascular complications.