Presence Of Vascular Calcification Research Articles

Calciprotein particle counts associate with vascular remodelling in chronic kidney disease.

Calciprotein particles (CPPs) are circulating calcium and phosphate nanoparticles associated with development of vascular calcification (VC) in chronic kidney disease (CKD). Although recent studies have been focusing on associations of CPPs with presence of VC in CKD, insights in the underlying processes and mechanisms by which CPPs might aggravate VC and vascular dysfunction in vivo are currently lacking. Here, we assessed overall burden of abdominal VC in healthy kidney donors and CKD patients, and subsequently performed transcriptome profiling in vascular tissue obtained from these subjects, linking outcome to CPP counts and calcification propensity. Calcification scores were quantified in renal arteries, iliac arteries and abdominal aorta, using computed tomography (CT) scans of kidney donors and CKD patients. Vascular tissue was collected from kidney donors (renal artery) and CKD patients (iliac artery), after which bulk RNA sequencing and gene set enrichment analysis (GSEA) was performed on a subset of patients. Calcification propensity (crystallization time, T50) was measured using nephelometry, and CPP counts with microparticle flow cytometric analysis. Increased calcification scores (based on CT) were found in CKD patients compared to kidney donors. Transcriptome profiling revealed enrichment for processes related to endothelial activation, inflammation, extracellular matrix (ECM) remodelling and ossification in CKD vascular biopsies compared to kidney donors. Calcification propensity was increased in CKD, as well as CPP counts, of which the latter significantly associated with markers of vascular remodelling. Our findings reveal that CKD is characterized by systemic VC with increased calcification propensity and CPP counts. Transcriptome profiling showed altered vascular gene expression with enrichment for endothelial activation, inflammation, ECM remodelling and ossification. Moreover, we demonstrate for the first time that vascular remodelling processes are associated with increased circulating CPP counts. Interventions targeting CPPs are promising avenues for alleviating vascular remodelling and VC in CKD.

THE PREDICTIVE VALUE OF VASCULAR CALCIFICATION ON PLAIN RADIOGRAPHS OF THE FOOT TO DIAGNOSE DIABETES MELLITUS

IntroductionThere are nearly 500,000 people with undiagnosed diabetes mellitus in the UK. The incidental finding vascular calcification on plain radiographs in patients with undiagnosed diabetes has the potential to alter patient management in those presenting with pathology. We hypothesised that the presence of vascular calcification on plain radiographs of the foot may predict the diagnosis of diabetes. The primary aim of this case control study was to determine the positive predictive value of vascular calcification to diagnose diabetes. Secondary aims were to determine the odds of having diabetes dependent on other known risk factors for calcification.MethodsA retrospective case control study of 130 diabetic patients were compared to 130 non-diabetic patients that were matched for age and gender. The presence of vascular calcification in anterior, posterior or plantar vessels, and length of calcification were measured on plain radiographs. McNemar's Chi-squared test and positive predictive values were calculated. Conditional logistic regression models were used to estimate the association between calcification and diabetes.Results28 patients had type I diabetes and 102 had type II diabetes. The mean age was 58.0 in both groups and 31.5% were females. 89.2% of those with diabetes had calcification present, and 23.1% in those without (p < 0.0001). Calcification in two vessels predicts diabetes with a positive predictive value of 91.2% (95% CI 82.1%–100%). The odds ratio for having diabetes is 78 (95% CI: 7.8 – 784) times higher in a person who has calcification in the blood vessels of their foot than in a person without calcification after adjusting for confounders.ConclusionThis study has demonstrated that vascular calcification in 2 vessels is over 90% predictive of a diagnosis of diabetes. This screening test could be used in future clinics when interpreting radiographs, aiding in the diagnosis of diabetes and altering patient management.

#176 System to detect vascular calcification through convolutional neural networks

Abstract Background and Aims Cardiovascular disease is the major cause of death in patients with chronic kidney disease (CKD). It is increasingly believed that the presence of vascular calcification (VC) increases the risk of mortality due to cardiovascular events. VC is very common in CKD, especially in hemodialysis patient. To improve the life expectancy of patients, it is important to detect VC in the early stages of the disease. There are several ways to discover VC such as computed tomography (CT) scans, echocardiography, and X-Ray among others. However, one of the best options is the usage of X-ray images because is an affordable and simpler process in comparison to using CT scans or echocardiography. However, the problem with X-ray images is the difficulty of finding a well-trained professional that can detect the VC after analyzing the images which leads to possible misleading diagnoses. The goal of this study is to develop a prototype that detects Vascular Calcification from X-ray images in an automated way using the power of Convolutional Neural Networks (CNN). Method To train a CNN to detect VC from lumbosacral spine X-ray images, a set of 700 DICOM files complemented with 236 JPEG images was available. After getting the images, they had to be anonymized, and data, such as name and age was removed from each image. Then, the images were divided into three datasets: Train, Test, and Validation. Given that the dataset was not balanced between the pictures with VC (Positive) and those with no VC (Negative), it had to be reduced (Table 1). The next step was implemented to clean the images and prepare them to feed the CNN. An example of preprocessing is that some X-ray images were of the entire body. For the analysis, the VC detection was assessed at the anterior and the posterior walls of the abdominal aorta adjacent to vertebrae L1-L4. In addition to that, the DICOM images were converted to JPEG. After having the dataset prepared, a CNN architecture had to be selected. To achieve it, a revision of modern CNN architectures was performed. Two items were considered when selecting these: the performance on the ImageNet Large Scale Visual Recognition Challenge (ILSVRC) and if there was an available pre-trained model. With that criteria, pre-trained EfficientNet-B0 and ResNet50 models were used to build the prototype due to the limited dataset. Results After having the dataset prepared, the architectures selected, and the pre-trained models, the Training, Validation and Test stages were executed. For Training, with EfficientNet-B0, the Accuracy was 86.9%, while for Validation, the Accuracy was 57.4% (Fig. 1). Using the RestNet50 model, the precision was 90.506% during Training, while for Validation, it was 54.8% (Fig. 2). Finally, during the Testing stage, ResNet50 had a better performance, because EfficientNetB0 detected 80% for the negative class and 60% for the positive class. After the CNN models were trained, an additional validation stage was performed to compare the model results with the analysis made by a radiologist and a nephrologist. This comparison determined that the model performed better with images having VC, while it was less accurate with images having no presence of VC. This contrast could have different reasons, one being possible false-positive images. Conclusion This study created a CNN model using pre-trained models on top of modern architectures such as EfficientNet-B0 and ResNet50. Tools were used to prepare the images as well as to train, validate and test the model. The Transfer Learning helped to build a model faster, giving high Accuracy rates with only a few images due to the limited dataset. However, the model could give better results if a wider and balanced set of images is available. Also, a better pre-processing stage can be executed to reduce false-positive images. For future work, this model can be used as the core of a system that not only accurately detects Vascular Calcification from X-Ray images, but also can determine the level of calcification using measures such as the Kauppila Index or Adragao.

Dual-Energy Computed Tomography Virtual Noncalcium Imaging of Intracranial Arteries in Acute Ischemic Stroke: Differentiation Between Acute Thrombus and Calcification.

Hyperdense artery sign (HAS) on noncontrast brain computed tomography (CT) indicates an acute thrombus within the cerebral artery. It is a valuable imaging biomarker for diagnosing large-vessel occlusion; however, its identification may be challenging with the presence of vascular calcification. Dual-energy CT virtual noncalcium (VNCa) imaging using a 3-material decomposition algorithm is helpful for differentiating between calcification and hemorrhage. This study aimed to clarify the potential of VNCa imaging for differentiating HAS from vascular calcification. Patients with acute ischemic stroke and large-vessel occlusion identified on MR angiography, who also underwent noncontrast dual-energy CT, were included. The 80 kV/Sn 140 kV mixed images, with a weighting factor of 0.4, were considered 120 kVp-equivalent images. Postprocessing using a 3-material decomposition algorithm to differentiate between calcium (Ca), cerebrospinal fluid, and hemorrhage was performed via a commercially available 3-dimensional workstation. A mixed image, VNCa image, color-coded Ca image, and color-coded Ca image with VNCa image overlay (color-coded Ca-overlay image) were obtained, and axial reconstruction with a 1-mm slice thickness was performed for each image type. Two experienced neuroradiologists conducted imaging evaluations in consensus. Thirty-four patients (mean age, 76.0 years; 21 male and 13 female patients) were included. The mixed and VNCa images revealed an HAS (indicating an acute clot) corresponding to the large-vessel occlusion site in 30 patients. Among them, the VNCa and color-coded Ca-overlay images enabled clear differentiation between the acute thrombus and adjacent vessel wall calcification in 5 patients. Among the other 4 patients, the VNCa, Ca-overlay, and Ca images identified calcified cerebral emboli in the M1 segment in 1 patient. For the other 3 patients, no high attenuation corresponding to magnetic resonance angiography findings was observed in any of the mixed, VNCa, Ca-overlay, or Ca images. VNCa and color-coded Ca-overlay images obtained via dual-energy brain CT enabled differentiation of acute thrombus from vessel wall calcification and calcified cerebral emboli in patients with acute ischemic stroke.

Effect of chronic kidney disease induced calcification on peripheral vascular perfusion using near-infrared spectroscopic imaging.

Low-cost techniques that can detect the presence of vascular calcification (VC) in chronic kidney disease (CKD) patients could improve clinical outcomes. In this study, we established a near-infrared spectroscopy-based imaging technique to determine changes in peripheral hemodynamics due to CKD-induced VC. Mice were fed a high-adenine diet with either normal or high levels of phosphate to induce CKD with and without VC, respectively. The mice tail was imaged to evaluate hemodynamic changes in response to occlusion. The rate of change in oxyhemoglobin in response to occlusion showed a statistically significant difference in the presence of VC in the mice.

#6037 VALUE OF ARTERIAL CALCIFICATION DETECTED BY UPPER LIMB DOPPLER ULTRASOUND IN ADVANCED CHRONIC KIDNEY DISEASE

Abstract Background and Aims Vascular calcification is a common complication of chronic kidney disease (CKD), particularly in end-stage-renal disease (ESRD) and is predictive of subsequent cardiovascular disease and mortality. The aim of the present study was to evaluate the relationship between arterial calcification assessed by doppler ultrasound (DUS) performed by the same observer and biochemical parameters of CKD-MBD as well as the standard-of-care therapy for CKD-MBD. Method We present a retrospective study of 454 patients who were evaluated by DUS for pre-surgical vascular mapping from 2018 to 2021. Both arms brachial, radial and cubital arteries were analyzed, and vascular calcification was classified as absent, mild or moderate/severe (presence of acoustic shadowing). Laboratory serum analysis of PTH, serum Calcium (sCa), serum phosphorous (sPi) and serum magnesium (sMg) were collected (with a maximum interval of 6 months from DUS evaluation). Mortality was also registered during follow-up period. Results The demographics and biochemistry of the study population are summarized in Table 1. Arterial calcification was observed in 91.6% (n = 416) of the patients, 62.3% (n = 259) had mild calcification and 37.7% (n = 157) presented moderate/severe calcification. In univariate analysis, male gender (OR 2.2, p < 0.023), age (OR 1.03, p < 0.003), phosphate binders (OR 0.55, p value < 0.03) and cinacalcet use (OR 0.28, p < 0.019) were independently associated with the presence of arterial vascular calcification. Presence of vascular calcification on DUS was associated to mortality. In patients with vascular calcifications, moderate/severe calcification was associated with diabetes mellitus (OR 2.85, p<0.000), male gender (OR 1.69, p < 0.012), PAD (OR 2.43, p <0.001) and hemodialysis therapy for more than 5 years (OR 3.00, p< 0.010). Cinacalcet, phosphate binders, serum calcium, phosphorous, PTH and mortality did not correlate with calcification severity. In the multivariate logistic regression analysis adjusted to age, gender, PAD and serum calcium and magnesium, we found that serum PTHi (OR 1.00, p<0.040), hemodialysis for more than one year (OR 4.44, p< 0.040) and diabetes mellitus (OR 3.95, p< 0.001) were associated with moderate/severe vascular disease. Conclusion Concerning CKD-MBD related markers our study showed that only phosphate binders and cinacalcet use were predictive of absence of vascular calcifications, however no causality could be advanced with these data. For serious calcification, in our multivariable model, only PTH had statistical significance. It is widely recognized the importance of monitoring serum PTH, calcium and Pi to reduce the adverse clinical events associated with CKB-MBD. Widespread implementation of DUS in pre-surgical mapping for VA construction is also an opportunity for vascular study and features as calcifications can be a surrogate of CKD-MBD and cardiovascular burden.

#5629 EFFECT OF HIGH PHOSPHORUS CONTENT/DIET ON MIR-145 LEVELS AND VASCULAR SMOOTH MUSCLE CELLS OSTEOGENIC DIFFERENTIATION

Abstract Background and Aims Phosphorus (P) is found in most foods as a natural component, but nowadays, with the rise in the consumption of processed foods, P intake has increased in the developed world. Elevated serum P in patients with chronic kidney disease (CKD) contributes to development of vascular calcification. However, it is poorly understood the relationship between high P dietary intake and vascular calcification in healthy population with normal renal function, and the molecular pathways responsible for the transdifferentiation of vascular smooth muscle cells (VSMCs) that precedes it. Recent studies show that miR-145 is the most abundant microRNA (miR) in VSMCs, and its decrease is associated with loss of contractile phenotype -lower α-actin levels- and increased osteogenic differentiation. In addition, low serum levels of miR-145 has been associated with the presence of vascular calcification. Thus, the aim of the study was to evaluate the effect of high P dietary intake on aortic and serum miR-145 levels, phenotypic alterations of VSMCs and vascular calcification. Method The study was performed: a) in vivo in aortas and serums from rats with normal renal function fed normal P (NP, 0,6% P -n = 10-) and high P diets (HP, 0,9% P -n = 10-), and b) in vitro exposing the VSMCs to different concentrations of P (up to 3 mM), and overexpressing and silencing miR-145 to investigate its potential role in the VSMCs phenotypic differentiation. Results a) In vivo study: The HP group showed higher serum P (NP: 1.29 [1.15-1.35] vs HP:1.40 [1.33-1.48] mmol/L, p = 0.02) and PTH levels (NP: 235.58 ± 75.58 vs HP: 498.67 ± 142.07 pg/ml, p = 0.0001), without significant differences in serum Ca and FGF23 levels. There were not differences in aortic Ca content, although there was a significant reduction in α-actin expression in the HP group (NP: 2.49 [2.10-3.25] vs HP:1.23 [1.04-1.50] R.U., p = 0.002). Moreover, the aortic and serum levels of miR-145 were lower in the HP group: aortic miR-145 (NP: 1.26 [0.97-1.49] vs HP: 0.56 [0.38-0.69] R.U., p = 0.004) and serum miR-145 (NP: 0.84 [0.70-0.99] vs HP: 0.37 [0.31-0.52] R.U., p = 0.001). b) In vitro study: A7r5 cells exposure to high P reduced miR-145 (1mM P: 1.00 [0.88-1.28] vs 3mM P: 0.41 [0.32-0.52], p = 0.001), and α -actin (1mM P: 1.03 [0.96-1.15] vs 3mM P: 0.73 [0.61-0.74], p = 0.0008) levels increasing Ca content in a P concentration-dependent manner (1 mM P: 0.24 [0.00-1.17]; 1.5 mM P: 0.66 [0.47-2.61]; 2 mM P: 2.72 [1.06-4.01]; 2.5 mM P: 4.60 [3.02-4.91]; 3 mM P: 5.81 [5.58-6.34], p = 0.000). the silencing of miR-145 under standard P content (1mM), decreased α -actin (control: 1.02 [0.99-1.04] vs miR-145 antagomir: 0.75 [0.69-0.90] R.U., p = 0.0007), meanwhile its overexpression increased it (control: 1.02 [0.99-1.04] vs miR-145 mimic: 2.70 [2.68-3.07] R.U., p = 0.001). The α -actin levels and Ca content were not modified after silencing miR-145 under high P conditions C (3 mM), meanwhile miR-145 overexpression under high P conditions increased α -actin levels (control: 0.54 [0.41-0.61] vs miR-145 mimic: 1.82 [1.68-2.04] R.U., p = 0.0005), and partially prevented the increases in Ca content (control: 182.77 [176.78-194.84] vs miR-145 mimic: 117.16 [112.27-122.69] R.U., p = 0.0005). Conclusion The results indicate the high P exposure could lead to an impairment of vascular health by causing decrease in miR-145 levels with the consequent reduction in α -actin expression in VSMC cells.

Serum sclerostin in vascular calcification in CKD: a meta-analysis

Vascular calcification (VC) is recognized as a predictor of all-cause and CVD mortality in chronic kidney disease (CKD). VC in CKD is possibly associated with serum sclerostin. The study systematically investigated the role of serum sclerostin in VC in CKD. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols, a systematic search was performed of the PubMed, Cochrane Library, and EMBASE databases from inception to 11 November 2022, to identify relevant eligible studies. The data were retrieved, analyzed, and summarized. The hazard ratios (HRs) and odds ratios (ORs) with their corresponding confidence intervals (CIs) were derived and pooled. Thirteen reports (3125 patients) met the inclusion criteria and were included. Sclerostin was associated with the presence of VC (pooled OR = 2.75, 95%CI = 1.81–4.19, p < 0.01) and all-cause mortality (pooled HR = 1.22, 95%CI = 1.19–1.25, p < 0.01) among patients with CKD, but with a decreased risk of cardiovascular events (HR = 0.98, 95%CI = 0.97–1.00, p = 0.02). This meta-analysis suggests that serum sclerostin is associated with VC and all-cause mortality among patients with CKD.

The predictive value of vascular calcification on plain radiographs of the ankle to diagnose diabetes mellitus

IntroductionThere are nearly 500,000 people with undiagnosed diabetes mellitus in the UK. A common complication of diabetes is vascular calcification. The incidental finding of vascular calcification on plain radiographs in patients with undiagnosed diabetes has the potential to alter patient management. We hypothesised that the presence of vascular calcification on plain radiographs of the foot may predict the diagnosis of diabetes and aimed to determine the positive predictive value of vascular calcification to diagnose diabetes. MethodsA retrospective case control study compared 130 diabetic patients to 130 non-diabetic patients that were matched for age and gender. The presence of vascular calcification in anterior, posterior or plantar vessels was measured on plain radiographs. McNemar’s Chi-squared test and positive predictive values were calculated. Conditional logistic regression models estimated the association between calcification and diabetes ResultsThe overall mean age was 58.0 % and 31.5 % were females. 89.2 % of those with diabetes had calcification present, and 23.1 % in those who did not have diabetes had calcification. McNemar’s test for independence gives p < 0.001.Calcification in both anterior and posterior vessels predicts diabetes with a positive predictive value of 91.2 % (95 % CI 76.9–97.0 %).The odds ratio for having diabetes is 78 (95 % CI: 7.8 – 784) times higher in a person who has calcification in the blood vessels of their ankle than in a person without calcification after adjusting for confounders ConclusionThis study has demonstrated that vascular calcification in the anterior and posterior blood vessels is over 90 % predictive of a diagnosis of diabetes. This screening test could be used in future clinics when interpreting radiographs, aiding in the diagnosis of diabetes and altering patient management.

32736 Characterizing calciphylaxis-like lesions in mice predisposed to vascular calcification

Calciphylaxis is a rare yet fatal form of vascular calcification often associated with end-stage renal disease (uremic calciphylaxis) and nonuremic causes. Calciphylaxis is associated with medial arteriolar vascular calcification and results in ischemic subcutaneous necrosis. We hypothesized that tissue-nonspecific alkaline phosphatase (TNAP), which is known to cause osteoblastic transformation of vascular cells, can contribute to the calcification of small arterioles in the skin. Our study aimed to characterize a mouse model of nonuremic calciphylaxis secondary to alkaline phosphatase overexpression in the vasculature. Eleven wild-type (WT) and 11 TNAP mice were evaluated at 23-week-old age on a regular diet. Alizarin and hematoxylin and eosin (H&E) staining of trunk skin cryosections revealed calcium deposits in TNAP mice. As visualized by vascular contrast micro-CT, calcifications appeared primarily vascular in nature and localized to the dermis and subcutaneous adipose tissue. Noncontrast micro-CT (n = 4 per group) revealed that calcification was present in all TNAP mice compared with its complete absence in WT mice. The presence of vascular calcification in adipose-rich trunks of the TNAP mice is consistent with the pattern of lesion formation in human calciphylaxis patients. Our mice tissues are most reflective of the earliest histologic manifestations, which lack ulcerations or necrotic lesions, but may be characterized by gross skin changes with intact epithelium. Our findings suggest that increased alkaline phosphatase activity in the vasculature can contribute to the pathophysiology of nonuremic calciphylaxis.

Sheathless use of Supera stent minimizes access complications in antegrade femoral puncture: Technical note with case series.

Antegrade femoral puncture (AFP) is the preferred strategy to treat lower limb obstructive disease. However, the presence of vascular calcification may be associated with procedure related adverse events, impairing endovascular device strategies. We describe a case series of superficial femoral and popliteal artery treatments by Supera stent implantation using a simple technique to significantly minimize the dimension of the antegrade femoral puncture from 6 to 4 French (Fr). All antegrade femoral punctures, crossing femoro-popliteal lesion and predilation were made with 4 Fr introducer. After preparation the Supera stent was navigated in sheathless fashion via 0.018-inch guidewire. Postdilation and final control were made replacing the 4 Fr introducer via the same guidewire. A good final result was achieved. Patients were discharged early without any complications. This minimally invasive technique in cases of infrainguinal peripheral artery disease could be feasible and effective for minimizing the risk of complications in patients with critical limb ischemia.

Calcium Score Predicts Mortality After Revascularization in Critical Limb Ischemia

Purpose: The calcium score is a measure of vessel wall calcification and has clinical applications when studied in different vascular beds. The presence of vascular calcification in the arteries of the lower limbs is very common in patients with peripheral arterial disease; however, its relationship with the postoperative outcomes in patients undergoing lower limb revascularization is still poorly studied. The aim of this study is to evaluate association between the calcium score of lower limbs and the postoperative outcomes in patients with peripheral arterial disease undergoing revascularization procedures. Methodology: We retrospectively analyzed 88 lower limb revascularization procedures in 72 patients with critical limb ischemia who had enhanced computed tomography for preoperative evaluation. The calcium score was calculated, from the angiographic phase of preoperative computed tomography, in the segments of the aorta, iliac, femoropopliteal, and infrapopliteal. It was also calculated the calcium score of the operated limb, and the total calcium score using a standardized method. The outcomes evaluated were the occurrence of acute myocardial infarction, amputation, patency, technical success, and death from any cause. Patients were followed up through a 12 month period. Results: Among the 88 procedures performed, 31 (43.1%) lesions were classified as Trans-Atlantic Inter-Society Consensus Document II D. There were 66 (75%) endovascular procedures, 16 (18.2%) open surgery, and 6 (6.8%) hybrid interventions. No statistically significant relationship was found between the calcium score of the segments (aorta, iliac, femoropopliteal, infrapopliteal, the operated limb, and total calcium score) and the outcomes of acute myocardial infarction, amputation, patency, and technical success in any of the periods analyzed. The calcium score of the operated limb was higher in patients who died within 30 days and 6 months (6571 vs 2590.6; p=0.026) and (5227.8 vs 2335.3; p=0.036). Conclusion: A standardized calcium score calculation method with the angiographic phase of the computed tomography is feasible and reproducible. Higher values of the calcifications of the operated limb are related to a greater chance of death in the postoperative period. The calcium score of the operated limb can be considered as a marker of clinical severity and prognosis in this group of patients

Serum and vascular fibroblast growth factor 23 (FGF23) are associated with vascular calcification

Background and Aims: Several studies associate the rise in the phosphatonin fibroblast growth factor 23 (FGF23) with the development of cardiovascular disease (CVD). This case-control study determined the association of serum and vascular FGF23 levels with the presence of vascular calcification (VC).

MO453SERUM AND VASCULAR FIBROBLAST GROWTH FACTOR 23 (FGF23) ARE ASSOCIATED WITH VASCULAR CALCIFICATION

Abstract Background and Aims Mineral metabolism imbalances and inflammation are related to the development of vascular calcification (VC). Fibroblast growth factor-23 (FGF23) is the main regulator of phosphate homeostasis and various studies have shown the existence of an association between elevated levels of FGF23 and the appearance of cardiovascular disease (CVD). We conducted a case-control study to test the hypothesis that serum and vascular levels of FGF23 are associated with the presence of VC. In addition, we determined the influence of inflammation in these levels. Method One hundred and thirty-three patients diagnosed with clinical atherosclerotic disease undergoing elective vascular surgery, and 20 cadaveric organ donors with no medical history of CVD, were included in this study. Serum levels of intact FGF23 (iFGF23), together with tumor necrosis factor-alpha (TNFα), interleukin (IL)10, were determined by ELISA. Vascular fragments of aorta, carotid and femoral arteries were obtained for assaying the gene expression of FGF23, TNF, IL10 and RUNX2 by qPCR. Immunohistochemical procedures were employed to determine vascular protein levels of FGF23, TNFα and IL10. VC was diagnosed by imaging techniques and confirmed by histological procedures including von Kossa staining. Results Case group presented a higher prevalence of hypertension, hypercholesterolemia and reduced estimated glomerular filtration rate, with no differences regarding other parameters. Serum iFGF23 and TNFα/IL10 ratio were higher in the case group (P&amp;lt;0.01 and P&amp;lt;0.001, respectively). Vascular expression of FGF23 was detected in 58.6% of CVD patients vs 35% of donors, with mean expression levels significantly higher in the first group (P&amp;lt;0.01). Vascular expression of TNF/IL10 was also increased (P&amp;lt;0.001) in CVD patients. FGF23 immunoreactivity was detected in 84% of CVD patients and only in 35% of controls. Immunoreactivity for FGF23 and TNFα/IL10 ratio were significantly higher in CVD patients (P&amp;lt;0.001 and P&amp;lt;0.0001, respectively). Stratified analysis according to serum iFGF23 levels showed a higher prevalence of VC in the upper tertiles. Patients with VC presented increased levels of all the FGF23 variables including serum [1.5 (1.2-1.6) vs. 1.4 (0.9-1.5) pg/mL, P&amp;lt;0.01], vascular mRNA [26.1 (14.3-67.4) vs. 18.8 (8.8-312.9) log AU, P&amp;lt;0.01] and vascular immunoreactivity [4.6 (3.8-4.9) vs. 3.7 (3.1-4.1) log µm2, P&amp;lt;0.05]. Moreover, FGF23 immunoreactivity was detected in 92.3% of fragments with VC and only in 53.6% of those without VC. Serum TNFα/IL10 and RUNX2 mRNA levels were also higher in this group (P&amp;lt;0.01 for both). Correlation analysis showed associations of serum iFGF23 with serum TNFα (r=0.375, P&amp;lt;0.001), neutrophil/lymphocyte (r=0.142, P&amp;lt;0.05), vascular RUNX2 mRNA (r=0.55, P&amp;lt;0.05), and vascular FGF23 immunoreactivity (r=0.281, P&amp;lt;0.05) in the CVD group. Vascular FGF23 expression correlated with RUNX2 mRNA (r=0.315, P&amp;lt;0.05) and FGF23 immunoreactivity (r=0.254, P&amp;lt;0.05). Multiple regression analysis showed that iFGF23 levels were determined by UAE, HDL, FGe, calcium and TNFα levels (adjusted R2= 0.473, P&amp;lt;0.0001) and that vascular FGF23 mRNA expression was determined by TNFα, PCR, glucose and age (adjusted R2= 0.795, P&amp;lt;0.0001). Multivariate logistic regression, with VC as dependent variable, showed that both iFGF23 and vascular mRNA constitute independent risk factors for the existence of VC [OR (95% CI): 1.05 and 1.12, P&amp;lt;0.05 for both]. Conclusion Patients with atherosclerosis and VC present significantly higher serum concentrations of FGF23, as well as higher immunoreactivity and gene expression levels in the vascular wall compared to patients without VC. Moreover, both serum and vascular mRNA levels of FGF23 are associated with the inflammatory status. Whether the increase in systemic and vascular FGF23 can directly promote or favor the calcifying process in the vascular bed is currently an issue under discussion.

Clinical Approach to Vascular Calcification in Patients With Non-dialysis Dependent Chronic Kidney Disease: Mineral-Bone Disorder-Related Aspects.

Chronic kidney disease (CKD) is associated with a very high morbimortality, mainly from cardiovascular origin, and CKD is currently considered in the high- or very high risk- cardiovascular risk category. CKD-mineral and bone disorders (CKD-MBDs), including vascular and/or valvular calcifications, are also associated with these poor outcomes. Vascular calcification (VC) is very prevalent (both intimal and medial), even in non-dialysis dependent patients, with a greater severity and more rapid progression. Simple X-ray based-scores such as Adragão's (AS) are useful prognostic tools and AS (even AS based on hand-X-ray only) may be superior to the classic Kauppila's score when evaluating non-dialysis CKD patients. Thus, in this mini-review, we briefly review CKD-MBD-related aspects of VC and its complex pathophysiology including the vast array of contributors and inhibitors. Furthermore, although VC is a surrogate marker and is not yet considered a treatment target, we consider that the presence of VC may be relevant in guiding therapeutic interventions, unless all patients are treated with the mindset of reducing the incidence or progression of VC with the currently available armamentarium. Avoiding phosphate loading, restricting calcium-based phosphate binders and high doses of vitamin D, and avoiding normalizing (within the normal limits for the assay) parathyroid hormone levels seem logical approaches. The availability of new drugs and future studies, including patients in early stages of CKD, may lead to significant improvements not only in patient risk stratification but also in attenuating the accelerated progression of VC in CKD.

Chronic Kidney Disease-Induced Vascular Calcification Impairs Bone Metabolism.

ABSTRACTAn association between lower bone mineral density (BMD) and presence of vascular calcification (VC) has been reported in several studies. Chronic kidney disease (CKD) causes detrimental disturbances in the mineral balance, bone turnover, and development of severe VC. Our group has previously demonstrated expression of Wnt inhibitors in calcified arteries of CKD rats. Therefore, we hypothesized that the CKD‐induced VC via this pathway signals to bone and induces bone loss. To address this novel hypothesis, we developed a new animal model using isogenic aorta transplantation (ATx). Severely calcified aortas from uremic rats were transplanted into healthy rats (uremic ATx). Transplantation of normal aortas into healthy rats (normal ATx) and age‐matched rats (control) served as control groups. Trabecular tissue mineral density, as measured by μCT, was significantly lower in uremic ATx rats compared with both control groups. Uremic ATx rats showed a significant upregulation of the mineralization inhibitors osteopontin and progressive ankylosis protein homolog in bone. In addition, we found significant changes in bone mRNA levels of several genes related to extracellular matrix, bone turnover, and Wnt signaling in uremic ATx rats, with no difference between normal ATx and control. The bone histomorphometry analysis showed significant lower osteoid area in uremic ATx compared with normal ATx along with a trend toward fewer osteoblasts as well as more osteoclasts in the erosion lacunae. Uremic ATx and normal ATx had similar trabecular number and thickness. The bone formation rate did not differ between the three groups. Plasma biochemistry, including sclerostin, kidney, and mineral parameters, were similar between all three groups. ex vivo cultures of aorta from uremic rats showed high secretion of the Wnt inhibitor sclerostin. In conclusion, the presence of VC lowers BMD, impairs bone metabolism, and affects several pathways in bone. The present results prove the existence of a vasculature to bone tissue cross‐talk. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Vascular calcification of chronic kidney disease: A brief review.

Vascular calcification (VC) is highly prevalent among patients with chronic kidney disease (CKD). There is growing evidence that there is more underlying this condition than the histological presentation of atherosclerotic plaque and arteriosclerosis and that the risk of cardiovascular disease in the context of CKD might be explained by the presence of VC. While VC has been observed in the absence of overt abnormal mineral metabolism, this association is coupled to abnormal homeostasis of minerals in patients with CKD, due to hyperphosphatemia and hypercalcemia. Furthermore, recent studies have shown that the differentiation of vascular smooth muscle cells into an osteogenic phenotype is highly regulated by pro-calcifying and anti-calcifying factors. There are several imaging modalities currently used in clinical practice to evaluate the extent and severity of VC; each has different advantages and limitations. Although there is no universally accepted method for the treatment of VC, there is growing evidence of the beneficial effects of medical therapy for the condition. This study discusses the mechanism underlying VC, imaging modalities used for evaluation of the condition, and possible treatments.

P1241CALCIFICATIONS IN DIFFERENT VASCULAR BEDS ACROSS THE SPECTRUM OF CHRONIC KIDNEY DISEASE INCLUDING CALCIFIC UREMIC ARTERIOLOPATHY: ARE SKIN PUNCH BIOPSIES USEFUL?

Abstract Background and Aims Accelerated vascular calcification in different vascular beds is common in patients with chronic kidney disease (CKD). A severe form of vascular calcifications is calcific uremic arteriolopathy (CUA) presenting with painful ischemic skin lesions and high mortality. The prognostic value of skin biopsies in relation to CUA is unclear and the prevalence of skin vascular calcifications in different stages of CKD is sparsely described. The aim of the study was to describe the occurence of small vesssel vascular calcifications in unaffected skin biopsies in relation to calcifications in other vascular beds across the spectrum of CKD including CUA. Method A cross-sectional cohort (total, n=39) comprising dialysis patients with current or previous CUA (CKD5D+CUA, n=9), dialysis patients without CUA (CKD5D-CUA, n=12), patients with CKD stage 3-4 (CKD3-4, n=12), and healthy kidney controls (control, n=6). The presence of vascular calcifications in the dermis and subcutis were assessed in 4 mm punch biopsies of unaffected skin from the lateral thigh. The presence of vascular calcification was evaluated by H&amp;E, von Kossa and Alizarin staining. The presence of breast arterial calcifications (BAC) was evaluated by mammography, the abdominal aortic calcification score (AAC) by lateral lumbar X-ray and calcification propensity was measured by T50 reflecting the calcification propensity in blood. Results None of the included patients showed vascular calcifications in skin biopsies. Declining kidney function was associated with presence of BAC, increased AAC and reduced T50 (Table). No significant difference was found between CKD5D+CUA and CKD5D-CUA regarding BAC (p=1.000), AAC (p=0.815) or T50 (p=0.165). CKD5D+CUA compared to all other groups had no difference in BAC (p=0.109) and AAC (p=0.141) but reduced T50 (p=0.004). Dialysis patients (CKD5D±CUA) had significant more BAC (p=0.003), higher AAC (p&amp;lt;0.001) and lower T50 (p&amp;lt;0.001). Conclusion No vascular calcifications were found in punch biopsies from unaffected skin in patients with different stages of CKD including CUA. Despite imaging verified vessel calcification by BAC and AAC and increased calcification propensity by T50. This suggest that conventional punch biopsies cannot be used to identify skin vascular calcification and thereby patients at risk for developing CUA.

P1642CORONARY ARTERY CALCIFICATION AMONG RENAL TRANSPLANT RECIPIENTS

Abstract Background and Aims Bone-mineral disease and vascular calcification are common complications in hemodialysis. The harmony between parathyroid hormone, calcium and phosphorus is impaired during hemodialysis and it supposed to be reversed by kidney transplantation but it is not known if the effect on vascular calcification will be reversed. Our aim is to study renal transplantation effect on hemodialysis associated vascular calcification and the risk factors for development and progression of vascular calcification. Method Transplant registry in Mansoura Urology and Nephrology Center, Egypt was reviewed for kidney transplant recipients (KTRs) who received renal allo-transplantation between January 2016 and December 2017 (149 KTRs). Patients were divided according to the presence of vascular calcification using non-contrast CT into 2 groups. Group I: 58 KTRs with pre-transplant vascular calcification, Group II: 91 KTRs without pre-transplant vascular calcification. Group I then were subdivided into 3 groups according to Agatston score (coronary calcium score) to 3 groups: Mild calcification (11-100), Moderate calcification (101-400), Severe calcification (&amp;gt;400). All patients were screened for coronary vascular calcification 2 years after transplantation using multi-slice coronary CT. Patients with detectable CAC at baseline and a CAC score change was ≥25% and patient with CAC score of 0 and follow up ≥ 4 were considered as progressors. Results The recipients` age in both group ranged from 18 years to 55 years. Older age is associated with higher incidence of vascular calcification (p value: 0.048) with male predominance and mean body mass index is 32.5±2.3. Majority of patients underwent hemodialysis before transplantation (90%). The longer hemodialysis duration, the more severe the degree of vascular calcification (p value: 0.003). There was no difference among both groups regarding CKD bone-mineral biomarkers except for intact PTH which was higher among vascular calcification patients (p value: 0.023). The majority of our patients received induction therapy; Basiliximab and received tacrolimus based immunosuppressive regimen. There was no significant difference regarding rejection episodes or post-transplant medical disorders. Presence of vascular calcification did not affect graft outcome over 2 years. Despite significant improvement in CKD-bone disease biomarkers (p value: 0.001; calcium, phosphorus, alk. phosphatase and intact PTH changes), Vascular calcification incidence increased after transplantation from 38.9% to 40.9% especially for severe form with rise of median agatston score from 258.85 (21,813) to 354.55(20, 1198.8). Patients were divided according to progression into 2 groups: progressors (59 KTRs) and non-progressors (90 KTRs). On comparison of both groups, there were 3 independent risk factors for CAC progression: pre-transplant Calcium score (Figure 1), dialysis duration (Figure 2) and pre-transplant PTH level (Figure 3) with significant p value: &amp;lt;0.001, &amp;lt;0.001 and 0.05 respectively. Pre-emptive transplantation is inversely proportional in determining CAC progression with p value: 0.02. ROC curve analyses were performed to evaluate the discriminatory power of the three parameters. Conclusion Baseline CAC, duration of dialysis and pre-transplant serum PTH level are factors associated CAC progression. Renal transplantation does not stop or reverse CAC. Progression of CAC is the usual evolution pattern of CAC in renal transplant recipients. Very important was the finding that the follow-up calcium Score was significantly related to the baseline score., which emphasizes the importance of primary prevention of CAC development.

MO054VASCULAR CALCIFICATION IMPAIRS BONE MINERALIZATION

Abstract Background and Aims Several studies report an association between low BMD and vascular calcification (VC) in the general population and in CKD patients. Development of VC in CKD is a cell regulated process where the vascular smooth muscle cell alters phenotype to a bone-like secretory cell. Our group has previously demonstrated the expression of Wnt inhibitors in VC and so we ask if the presence of VC affects bone metabolism. Method A novel model of isogenic aorta transplantation (ATx) was developed and used in the study. Severe uremic vascular calcifications were induced in inbred Dark Aguti (DA) rats by 5/6 nephrectomy, high phosphate diet and calcitriol treatment. After 14 weeks the calcified abdominal aorta of the uremic rat was transplanted into a normal DA rat (uremic ATx, n=16). A normal aorta was transplanted into a normal DA rat as sham group (normal ATx, n=9) and age-matched normal rats were used as one more control group (control, n=6). Rats were sacrificed 4 weeks after ATx and plasma biochemistry, bone and vessels were analyzed. Data are presented as mean±SEM or median [range]. Statistical significance *p&amp;lt;0.5,**p&amp;lt;0.01,*** p&amp;lt;0.001. Results The uremic donor rat suffered from severe kidney disease with disturbed mineral balance and its aorta had a high calcium content of 15.7±0.8 µg Ca/mg vs. none in the normal aorta. Uremic ATx, normal ATx and control rats had same plasma levels of creatinine, Ca2+, phosphate, PTH, FGF23 and sclerostin. The uremic ATx had significant lower bone mineral density (BMD) compared to normal ATx and control rats (1576±5 vs. 1592±5* &amp; 1613±6* mg/cc). The impact on bone mineralization was also detected in the bone histomorphometry analysis, where the uremic ATx had less osteoid compared to normal ATx (median 3% [0,3%;8%] vs. 5% [2%;8%]*). Moreover, the uremic ATx had fewer osteoblasts and more osteoclasts. The effect on bone was supported by substantial gene analysis of several genes related to bone remodeling, mineralization and Wnt signaling. The uremic ATx rats had significant changes in mRNA levels of several genes in bone compared to normal ATX and control rats such as increased alkaline phosphatase (3.26±0.29 vs. 1.56±0.32*** &amp; 0.86±0.12***), decreased osteoblast marker osteocalcin (0.54±0.06 vs. 0.92±0.14* &amp; 1.19±0.06***) and increased osteoclast marker cathepsin K (2.36±0.24 vs. 1.19±0.23** &amp; 1.01±0.07***). In addition, we found upregulation of the bone mineralization inhibitors osteopontin (1.46±0.18 vs. 0.69±0.17** &amp; 0.49±0.06**) and progressive ankylosis protein homolog (8.10±0.60 vs. 3.21±0.74** &amp; 2.39±0.48**) as well as collagen I (9.30 [2.73;14.81] vs. 2.30 [0.31;19.33]* &amp; 2.78 [1.63;7.52]***). The inhibitor of bone formation sclerostin was significant increased (2.90 [1.54;13,29] vs. 1,23 [0.32;3.20]** &amp; 0.93 [0.39;2,19]**) along with a slight downregulation of bone stimulator BMP2 (3.18±0.15 vs. 4.06±0.30* &amp; 3.98±0.44*. Finally, the Wnt signaling pathway was affected by upregulation of β-catenin (3.15±0.25 vs. 1.28±0.26*** &amp; 1.03±0.13***) and the downstream gene Snail1 (3.73±0.33 vs. 1.54±0.45*** &amp; 1.04±0.12***). Conclusion These novel findings indicate the existence of a tissue crosstalk between vessels and bone. The presence of vascular calcification lowers BMD, decreases the amount of osteoid and affects several pathways in bone.