Accelerated atherosclerotic calcification and Monckeberg's sclerosis: a continuum of advanced vascular pathology in chronic kidney disease

Ultrastructural changes of vascular smooth muscle cells and resistance to vasospasm treatment in femoral arteries of an arteriosclerotic rat model

The objective of this study was to establish an animal model of arteriosclerosis for assessing vasospasm and to investigate the relationship between arteriosclerosis and vasospasm. Twelve-week-old male Sprague-Dawley rats were fed a diet supplemented with adenine and vitamin D (adenine/vitD). Body weight, blood, and femoral artery histopathology were assessed at 2, 4, and 6 weeks. Change in the femoral artery was examined by transmission electron microscope (TEM). Vasospasm was induced by administering epinephrine extravascularly into the femoral artery and released by the treatment with lidocaine as a vasodilator. During this period, the extravascular diameter and blood flow were measured. The rats in the adenine/vitD group developed renal dysfunction, uremia, hyperphosphatemia, and elevated serum alkaline phosphatase. Histological and TEM analyses of the femoral arteries in the treated rats revealed the degeneration of elastic fibers and extensive calcification of the tunica media and intima. Vascular smooth muscles were degenerated and osteoblasts were developed, resulting in calcified arteriosclerosis. Vasospasm in arteriosclerotic arteries was detected; however, vasodilation as well as an increase in the blood flow was not observed. This study revealed the development of vasospasm in the femoral arteries of the arteriosclerotic rats and, a conventional vasodilator did not release the vasospasm.

Early diagnosis of aortic calcification through dental X-ray examination for dental pulp stones

Vascular calcification, an ectopic calcification exacerbated by aging and renal dysfunction, is closely associated with cardiovascular disease. However, early detection indicators are limited. This study focused on dental pulp stones, ectopic calcifications found in oral tissues that are easily identifiable on dental radiographs. Our investigation explored the frequency and timing of these calcifications in different locations and their relationship to aortic calcification. In cadavers, we examined the association between the frequency of dental pulp stones and aortic calcification, revealing a significant association. Notably, dental pulp stones appeared prior to aortic calcification. Using a rat model of hyperphosphatemia, we confirmed that dental pulp stones formed earlier than calcification in the aortic arch. Interestingly, there were very few instances of aortic calcification without dental pulp stones. Additionally, we conducted cell culture experiments with vascular smooth muscle cells (SMCs) and dental pulp cells (DPCs) to explore the regulatory mechanism underlying high phosphate-mediated calcification. We found that DPCs produced calcification deposits more rapidly and exhibited a stronger augmentation of osteoblast differentiation markers compared with SMCs. In conclusion, the observation of dental pulp stones through X-ray examination during dental checkups could be a valuable method for early diagnosis of aortic calcification risk.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Calcification detection on upper extremity arteries: a comparison of ultrasonic and X-ray methods

Background

Vascular calcification (VC) has been observed in patients with hemodialysis, whereas few studies have investigated calcification in the upper extremity vasculature. Both ultrasound and X-ray are used to investigate the calcification of arteries in patients. However, there is a lack of data on the consistency between these two methods. The aim of this study was to investigate the occurrence of VC in the radial and ulnar arteries of hemodialysis patients and investigate the detection consistency in VC between ultrasound and X-ray.

Methods

Ultrasound and X-ray examinations were performed in the radial and ulnar arteries of both the left and right upper extremities of 40 patients on hemodialysis. The calcification status of arteries was evaluated by the calcification index from ultrasound and X-ray respectively. Clinical variables of patients were collected from all the involved patients.

Results

Of the 40 patients, VC was detected in 31 patients by ultrasound, while X-ray detected VC in 22 patients. Compared to ultrasound assessment, X-ray assessment was 73.21% sensitive but only 66.35% specific with a positive predictive value of 53.95% for detecting calcifications in the radial or ulnar artery. The level of agreement between ultrasound and X-ray results was fair. In addition, our data showed that more ulnar arteries had VCs than the corresponding radial arteries.

Conclusion

Ultrasound is more sensitive in detecting the presence of calcified atherosclerotic lesions. Ultrasound and X-ray exhibited fair consistency. Ultrasound screening for upper extremity radial and ulnar arteries in hemodialysis patients may deserve attention to explore its clinical significance.

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

Association of Aortic Arch Calcification with Acute Ischemic Stroke Subtypes and Endovascular Thrombectomy Outcomes

PURPOSE

To analyze the aortic arch calcification (AAC) on computed tomography (CT) scans, with the goal of predicting the subtypes of patients with ischemic stroke and endovascular thrombectomy (EVT) outcomes.

MATERIALS AND METHODS

Automated analysis was used to quantify AAC on CT scans. From January 2020 to March 2021, 119 patients diagnosed with ischemic stroke were analyzed, and the feasibility of EVT was assessed; 43 underwent the procedure.

RESULTS

AAC was present in 117 (98.3%) of 119 patients. There was a significant difference (P <.001) in AAC severity among all patients with ischemic stroke according to the Trial of ORG 10172 in Acute Stroke Treatment classification. In patients who underwent EVT, AAC severity was significantly related to the thrombolysis in cerebral infarction grade, thrombectomy procedure time, and modified Rankin scale at discharge (P =.002, P =.035 and P =.015, respectively). Multivariate logistic regression analysis also showed that severe AAC (volume, ≥1,000 mm³) (adjusted odds ratio [OR], 12.1; adjusted 95% confidence interval [CI]), 2.1-36.4; P =.001) and intracranial atherosclerotic disease (adjusted OR, 9.5; adjusted 95% CI, 2.3-33.7; P =.001) were both independently associated with poor thrombolysis reperfusion rate.

CONCLUSIONS

A high proportion of patients with ischemic stroke have AAC, the severity of which is a potential imaging marker of ischemic stroke subtypes and the outcome of EVT.

25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) induces ectopic calcification

Vascular calcification is an important pathogenesis related to cardiovascular disease and high mortality rate in chronic kidney disease (CKD) patients. It has been well-known that hyper-phosphatemia induces osteochondrogenic transition of vascular smooth muscle cells (VSMCs) resulting ectopic calcification in aortic media, cardiac valve, and kidney. However, the detailed mechanism of the ectopic calcification has been not clarified yet. Here, we found that the co-localization of CYP27B1 with the calcified lesions of aorta and arteries in kidney of klotho mutant (kl/kl) mice, and then investigated the role of CYP27B1 in the mineralization of the VSMCs. Under high phosphate condition, overexpression of CYP27B1 induced calcification and osteocalcin mRNA expression in the VSMCs. Inversely, siRNA-CYP27B1 inhibited high phosphate-induced calcification of the VSMCs. We also found that the accumulated CYP27B1 protein was glycosylated in the kidney of kl/kl mice. Therefore, overexpression of CYP27B1-N310A and CYP27B1-T439A, which are a mutation for N-linked glycosylation site (N310A) and a mutation for O-linked glycosylation site (T439A) in CYP27B1, decreased calcium deposition and expression of RUNX2 induced by high phosphate medium in VSMCs compared with wild-type CYP27B1. These results suggest that extra-renal expression of glycosylated CYP27B1 would be required for ectopic calcification of VSMCs under hyperphosphatemia.

Interventions to Attenuate Vascular Calcification Progression in Chronic Kidney Disease: A Systematic Review of Clinical Trials

Background Vascular calcification is associated with cardiovascular morbidity and mortality in people with chronic kidney disease (CKD). Evidence-based interventions that may attenuate its progression in CKD remain uncertain.

Methods We conducted a systematic review of prospective clinical trials of interventions to attenuate vascular calcification in people with CKD, compare with placebo, another comparator, or standard of care. We included prospective clinical trials (randomized and nonrandomized) involving participants with stage 3-5D CKD or kidney transplant recipients; the outcome was vascular calcification measured using radiological methods. Quality of evidence was determined by the Cochrane risk of bias assessment tool and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) method.

Results There were 77 trials (63 randomized) involving 6898 participants eligible for inclusion (median sample size, 50; median duration, 12 months); 58 involved participants on dialysis, 15 involved individuals with nondialysis CKD, and 4 involved kidney transplant recipients. Risk of bias was moderate over all. Trials involving magnesium and sodium thiosulfate consistently showed attenuation of vascular calcification. Trials involving intestinal phosphate binders, alterations in dialysate calcium concentration, vitamin K therapy, calcimimetics, and antiresorptive agents had conflicting or inconclusive outcomes. Trials involving vitamin D therapy and HMG-CoA reductase inhibitors did not demonstrate attenuation of vascular calcification. Mixed results were reported for single studies of exercise, vitamin E-coated or high-flux hemodialysis membranes, interdialytic sodium bicarbonate, SNF472, spironolactone, sotatercept, nicotinamide, and oral activated charcoal.

Conclusions Currently, there are insufficient or conflicting data regarding interventions evaluated in clinical trials for mitigation of vascular calcification in people with CKD. Therapy involving magnesium or sodium thiosulfate appears most promising, but evaluable studies were small and of short duration.

Carbamylated sortilin associates with cardiovascular calcification in patients with chronic kidney disease

Sortilin, an intracellular sorting receptor, has been identified as a cardiovascular risk factor in the general population. Patients with chronic kidney disease (CKD) are highly susceptible to develop cardiovascular complications such as calcification. However, specific CKD-induced posttranslational protein modifications of sortilin and their link to cardiovascular calcification remain unknown. To investigate this, we examined two independent CKD cohorts for carbamylation of circulating sortilin and detected increased carbamylated sortilin lysine residues in the extracellular domain of sortilin with kidney function decline using targeted mass spectrometry. Structure analysis predicted altered ligand binding by carbamylated sortilin, which was verified by binding studies using surface plasmon resonance measurement, showing an increased affinity of interleukin 6 to in vitro carbamylated sortilin. Further, carbamylated sortilin increased vascular calcification in vitro and ex vivo that was accelerated by interleukin 6. Imaging by mass spectrometry of human calcified arteries revealed in situ carbamylated sortilin. In patients with CKD, sortilin carbamylation was associated with coronary artery calcification, independent of age and kidney function. Moreover, patients with carbamylated sortilin displayed significantly faster progression of coronary artery calcification than patients without sortilin carbamylation. Thus, carbamylated sortilin may be a risk factor for cardiovascular calcification and may contribute to elevated cardiovascular complications in patients with CKD.

Calcified facial and maxillary arteries: Incidental radiographic findings indicative of Mönckeberg arteriosclerosis

BACKGROUND AND OVERVIEW

Mönckeberg arteriosclerosis is a disease of unknown etiology characterized by dystrophic calcifications within the tunica media of small- and medium-sized arteries, leading to reduced arterial compliance. The authors report a case discovered incidentally on dental radiographs.

CASE DESCRIPTION

A 78-year-old man with a complex medical history was seen for routine oral health care. Panoramic and bite-wing radiographs revealed a tortuous, linear calcification in the area of the left mandibular first molar anterior to the angle of the mandible and suggestive of a calcified facial artery.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Medical radiologists have used the presence of arterial calcifications to determine the severity and prognosis of such diseases as primary hyperparathyroidism, secondary hyperparathyroidism, coronary artery disease, and diabetes. The presence of Mönckeberg arteriosclerosis on dental radiographs can help oral health care professionals identify patients with undiagnosed systemic disease.

Vascular Calcification as a Novel Risk Factor for Kidney Function Deterioration in the Nonelderly

Background

The relationship between vascular calcification and chronic kidney disease is well known. However, whether vascular calcification affects renal function deterioration remains unclear. We investigated whether kidney function deteriorated more rapidly in individuals with higher vascular calcification indicated by the coronary artery calcium score (CACS).

Methods and Results

Individuals with a normal estimated glomerular filtration rate (>60 mL/min per 1.73 m²) who underwent cardiac computed tomography in our institution (a tertiary teaching hospital in Cheonan, Korea) from January 2010 to July 2012 were retrospectively reviewed. All participants were aged 20 to 65 years. Among 739 patients, 447, 175, and 117 had CACSs of 0, 1 to 99, and ≥100 units, respectively. The participants were followed for 7.8 (interquartile range, 5.5–8.8) years. The adjusted annual estimated glomerular filtration rates declined more rapidly in patients in the CACS ≥100 group compared with those in the CACS 0 group (adjusted‐β, −0.40; 95% CI, −0.80 to −0.03) when estimated using a linear mixed model. The adjusted hazard ratio in the CACS ≥100 group for Kidney Disease: Improving Global Outcomes criteria (a drop in estimated glomerular filtration rate category accompanied by a 25% or greater drop in estimated glomerular filtration rate) was 2.52 (1.13–5.61). After propensity score matching, more prevalent renal outcomes (13.2%) were observed in patients with a CACS of ≥100 compared with those with a CACS of 0 (1.9%), with statistical significance (P=0.004).

Conclusions

Our results showed that renal function declined more rapidly in patients with higher CACSs, suggesting that vascular calcification might be associated with chronic kidney disease progression.

Calcification of lower extremity arteries is related to the presence of osteoporosis in postmenopausal women with type 2 diabetes mellitus: a cross-sectional observational study

It is unknown whether there is any relationship between extremity arterial macroangiopathy and osteoporosis in type 2 diabetic mellitus (T2DM) patients. We provide evidence to show the association between lower extremity arterial calcification and the presence of osteoporosis in postmenopausal T2DM women, but not in T2DM men of similar age.

PURPOSE

To investigate the relationship between lower extremity arterial calcification and the presence of osteoporosis in type 2 diabetic mellitus (T2DM) patients.

METHODS

We performed a retrospective cross-sectional study in patients with T2DM. They were assigned into two groups (patients with or without vascular calcification) in both sexes. Clinical characteristics, presence of osteoporosis, and bone metabolic markers were compared. Arterial calcification was determined by ultrasonography examination. Osteoporosis was defined based on the measurements from dual-energy X-ray absorptiometry. The relationship between the lower extremity arterial calcification and the presence of osteoporosis was analyzed. Statistical analysis was performed in SPSS 26.0.

RESULTS

A total of 933 T2DM patients (535 men ≥ 50 years old, and 398 postmenopausal women) were identified and analyzed. A significant association between arterial calcification and osteoporosis was only observed in women, with a higher prevalence of osteoporosis observed in women with calcification (40.8%) than in women without calcification (26.9%) (P = 0.004). Compared to women without calcification, women with calcification had lower bone mineral densities in the hip (P < 0.001) and femoral neck (P < 0.001). Ordinal logistic regression analysis showed that women with calcification had a nearly 2-fold increased risk for osteoporosis, even after adjusting for age, duration of T2DM, body mass index, pulse pressure, clearance of creatinine, glycosylated hemoglobin, and fasting C-peptide. Similar differences were not identified between men with and without calcification.

CONCLUSION

Calcification of lower extremity arteries is related with the presence of osteoporosis in postmenopausal T2DM women.

Effect of alirocumab on major adverse cardiovascular events according to renal function in patients with a recent acute coronary syndrome: prespecified analysis from the ODYSSEY OUTCOMES randomized clinical trial

Aims

Statins reduce cardiovascular risk in patients with acute coronary syndrome (ACS) and normal-to-moderately impaired renal function. It is not known whether proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors provide similar benefit across a range of renal function. We determined whether effects of the PCSK9 inhibitor alirocumab to reduce cardiovascular events and death after ACS are influenced by renal function.

Methods and results

ODYSSEY OUTCOMES compared alirocumab with placebo in patients with recent ACS and dyslipidaemia despite intensive statin treatment. Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m² was exclusionary. In 18 918 patients, baseline eGFR was 82.8 ± 17.6 mL/min/1.73 m², and low-density lipoprotein cholesterol (LDL-C) was 92 ± 31 mg/dL. At 36 months, alirocumab decreased LDL-C by 48.5% vs. placebo but did not affect eGFR (P = 0.65). Overall, alirocumab reduced risk of the primary outcome (coronary heart disease death, non-fatal myocardial infarction, ischaemic stroke, or unstable angina requiring hospitalization) with fewer deaths. There was no interaction between continuous eGFR and treatment on the primary outcome or death (P = 0.14 and 0.59, respectively). Alirocumab reduced primary outcomes in patients with eGFR ≥90 mL/min/1.73 m² (n = 7470; hazard ratio 0.784, 95% confidence interval 0.670–0.919; P = 0.003) and 60 to <90 (n = 9326; 0.833, 0.731–0.949; P = 0.006), but not in those with eGFR < 60 (n = 2122; 0.974, 0.805–1.178; P = 0.784). Adverse events other than local injection-site reactions were similar in both groups across all categories of eGFR.

Conclusions

In patients with recent ACS, alirocumab was associated with fewer cardiovascular events and deaths across the range of renal function studied, with larger relative risk reductions in those with eGFR > 60 mL/min/1.73 m².

Multiple extremity necrosis in fatal calciphylaxis: Case report

INTRODUCTION

The clinical impact of vascular calcification is well established in the context of cardiovascular morbidity and mortality, but other clinical syndromes, such as calciphylaxis, although less frequent, have a significant impact on chronic kidney disease.

METHODS

Case report of a 27-year-old woman, who had complained of bilateral pain in her toes for 3 days, with the presence of small necrotic areas in the referred sites. She had a history of type 1 diabetes (25 years ago), with chronic kidney disease, on peritoneal dialysis, in addition to rheumatoid arthritis. She was admitted to the hospital, which preceded the current condition, due to exacerbation of rheumatoid arthritis, evolving with intracardiac thrombus due to venous catheter complications, when she started using warfarin. Ischemia progressed to her feet, causing the need for bilateral amputations. Her chirodactyls were also affected. Thrombophilia, vasculitis, endocarditis or other embolic sources were investigated and discarded. Her pathology report evidenced skin necrosis and superficial soft parts with recent arterial thrombosis, and Monckeberg's medial calcification. We started treatment with bisphosphonate and sodium thiosulfate, conversion to hemodialysis and replacement of warfarin with unfractionated heparin. Despite all the therapy, the patient died after four months of evolution.

DISCUSSION

Calciphylaxis is a rare microvasculature calcification syndrome that results in severe ischemic injuries. It has pathogenesis related to the mineral and bone disorder of chronic kidney disease combined with the imbalance between promoters and inhibitors of vascular calcification, with particular importance to vitamin K antagonism.

CONCLUSION

The preventive strategy is fundamental, since the therapy is complex with poorly validated effectiveness.

Arterial medial calcification (Mönckeberg's sclerosis) with chronic renal disease in a zoo-kept Southern tamandua (Tamandua tetradactyla)

Arterial medial calcification observed in animals is equivalent to Mönckeberg’s sclerosis in human beings. This lesion is rarely reported in domestic animals. In addition, little information is available concerning the occurrence of arterial medial calcification in zoo animals. The aim of the current work was to report arterial medial calcification incidentally encountered in a Southern tamandua (Tamandua tetradactyla). This paper described the clinical findings, haematological and serum biochemical profiles, and histopathological results. Haematological examinations showed decreases in white blood cell counts, erythrocytic parameters and platelets. In serum biochemical examinations, both of the creatinine and blood urea nitrogen levels markedly increased in this study. Glucose concentrations dramatically declined from the normal levels to the critical conditions. There was electrolytic imbalance which was not accompanied by increases in calcium and inorganic phosphorus concentrations.

Enzyme activities (ALP, AST, ALP, γ-GT, LDH and CK) remarkably increased just before the animal died. Histopathological examinations revealed that this marked and thickened calcification extended linearly around the circumference of the vessels. The calcified deposits were located entirely within the medial layer of the arterial wall. The lesions showed involvement of the internal elastic lamina with calcification. Severe calcification was observed in the glomerular capsules, indicating serious chronic kidney disease. We concluded that arterial medial calcification in the Southern tamandua arose with progressing chronic kidney failure.

Outcome of distal lower leg reconstruction with the propeller perforator flap in diabetic patients

In diabetic foot patients, wound coverage options are quite limited due to vascular abnormalities. However, even though significant atherosclerotic changes are found in major vessels of the lower leg in diabetic foot patients, perforating vessels, which are used as the vascular pedicle of propeller perforator flaps, are often spared from atherosclerosis. Therefore, the propeller perforator flap could be an alternative option for diabetic foot patients. The purpose of this study was to compare the outcome of the propeller perforator flap between diabetic and nondiabetic patients in reconstruction of the distal lower leg. We retrospectively included all patients who underwent reconstruction of the distal lower leg with a propeller flap between 2014 and 2018. Thirty-five propeller perforator flaps in 20 diabetic patients and 15 nondiabetic patients were included. Of the 35 patients, 21 showed complete healing, and 14 showed flap complications. The rate of complications in diabetic patients was approximately 85.7%. Sex (p = .002), diabetes (p = .007), chronic renal failure (p < .001), and diabetic neuropathy (p = .011) were associated with flap complications. Crude regression analysis showed that the female sex (p = .002), diabetes (p = .01), and diabetic neuropathy (p = .012) were significant risk factors for the occurrence of any complications, but the significance of diabetes and diabetic neuropathy was not maintained in the adjusted models. Therefore, the propeller perforator flap might not be effective for reconstructing diabetic foot ulcers.

CREB/ATF3 signaling mediates indoxyl sulfate-induced vascular smooth muscle cell proliferation and neointimal formation in uremia

BACKGROUND AND AIMS

Uremic patients are characterized by an increased risk of atherosclerotic cardiovascular diseases. Vascular smooth muscle cell (VSMC) proliferation contributes to neointimal formation, a main pathological feature in atherosclerosis. Activation of CREB/ATF3 signaling is pivotal in VSMC proliferation, yet its role in uremic atherosclerosis is unknown. This study aimed to explore whether CREB/ATF3 signaling is involved in the molecular mechanism underlying neointimal formation in uremia.

METHODS AND RESULTS

Treatment of VSMCs with uremic toxin (indoxyl sulfate [IS]) activated cAMP/CREB/ATF3/cyclin D signaling, which was reflected by increased VSMC proliferation. Blocking cAMP/PKA/CREB/ATF3 signaling attenuated the promoting effect of IS on cyclin D1 expression and VSMC proliferation. Loss-of-function and time-dependent experiments showed that ATF3 lies downstream of the CREB signaling. Mutational analysis of cyclin D1 promoter along with chromatin immunoprecipitation assays showed that CREB/ATF3 signaling participated in IS-induced cyclin D transcription. In vivo, phosphorylated CREB (an active form of CREB) and ATF3 were prominently upregulated in the neointima of experimental uremic rats, the atherosclerotic plaques of uremic ApoE^-/- mice, and the iliac arteries of uremic patients. Notably, the use of lentivirus to knock down ATF3 in the neointima of balloon-injured arteries could suppress the effect of uremia in vivo, including neointimal formation and cyclin D expression.

CONCLUSIONS

In this study, we demonstrated that CREB/ATF3-related signaling may be involved in IS-induced VSMC proliferation and the pathogenesis of neointimal formation during uremia.

A Land of Controversy: Fibroblast Growth Factor-23 and Uremic Cardiac Hypertrophy

Cardiac hypertrophy is a common feature in patients with CKD. Recent studies revealed that two phosphate regulators, fibroblast growth factor-23 and α-Klotho, are highly involved in the pathophysiologic process of CKD-induced cardiac hypertrophy. With decreasing renal function, elevated fibroblast growth factor-23 and decreased α-Klotho may contribute to cardiac hypertrophy by targeting the heart directly or by inducing systemic changes, such as vascular injury, hemodynamic disorders, and inflammation. However, several studies have demonstrated that disturbances in the fibroblast growth factor-23/α-Klotho axis do not lead to cardiac hypertrophy. In this review, we describe the cardiac effects of the fibroblast growth factor-23/α-Klotho axis and summarize recent progress in this field. In addition, we present not only the main controversies in this field but also provide possible directions to resolve these disputes.

TDAG51 (T-Cell Death-Associated Gene 51) Is a Key Modulator of Vascular Calcification and Osteogenic Transdifferentiation of Arterial Smooth Muscle Cells

OBJECTIVE

Cardiovascular disease is the primary cause of mortality in patients with chronic kidney disease. Vascular calcification (VC) in the medial layer of the vessel wall is a unique and prominent feature in patients with advanced chronic kidney disease and is now recognized as an important predictor and independent risk factor for cardiovascular and all-cause mortality in these patients. VC in chronic kidney disease is triggered by the transformation of vascular smooth muscle cells (VSMCs) into osteoblasts as a consequence of elevated circulating inorganic phosphate (P_i) levels, due to poor kidney function. The objective of our study was to investigate the role of TDAG51 (T-cell death-associated gene 51) in the development of medial VC.

METHODS AND RESULTS

Using primary mouse and human VSMCs, we found that TDAG51 is induced in VSMCs by P_i and is expressed in the medial layer of calcified human vessels. Furthermore, the transcriptional activity of RUNX2 (Runt-related transcription factor 2), a well-established driver of P_i-mediated VC, is reduced in TDAG51^-/- VSMCs. To explain these observations, we identified that TDAG51^-/- VSMCs express reduced levels of the type III sodium-dependent P_i transporter, Pit-1, a solute transporter, a solute transporter, a solute transporter responsible for cellular P_i uptake. Significantly, in response to hyperphosphatemia induced by vitamin D₃, medial VC was attenuated in TDAG51^-/- mice.

CONCLUSIONS

Our studies highlight TDAG51 as an important mediator of P_i-induced VC in VSMCs through the downregulation of Pit-1. As such, TDAG51 may represent a therapeutic target for the prevention of VC and cardiovascular disease in patients with chronic kidney disease.

Asymmetric dimethylarginine and angiopoietin-like protein-2 are independent predictors of cardiovascular risk in pre-dialysis non-diabetic chronic kidney disease patients

BACKGROUND

Chronic kidney disease (CKD) is associated with increased cardiovascular (CVD) morbidity and mortality. Hence, this study was carried out to assess the biomarkers of endothelial dysfunction and inflammation as predictors of CVD risk in Indian patients with CKD.

METHODS

In this case control study, we recruited 43 patients with CKD and 43 healthy control volunteers. Circulating levels of endothelial dysfunction markers [asymmetric dimethylarginine (ADMA), angiopoietin-like protein-2 (ANGPTL2), matrix metallopeptidase 9 (MMP-9)] and systemic inflammation [high-sensitivity C-reactive protein (hs-CRP)] were assessed in the study population. All study participants underwent brachial artery flow mediated dilation (FMD) to estimate endothelial dysfunction. Disease severity (e-GFR) was assessed by a nephrologist.

RESULTS

CKD patients showed markedly elevated levels of ADMA, ANGPTL2, MMP-9, and hs-CRP. FMD and eGFR were significantly decreased in cases, as compared to the controls. ADMA, ANGPTL2, MMP-9 and hs-CRP showed significant positive correlation with one another and significant negative correlation with FMD and disease severity. We also observed a significant negative correlation of FMD with disease severity and duration of CKD. In the multiple linear regression model, ADMA and ANGPTL2 were found to be independent predictors of FMD.

CONCLUSION

In CKD patients, there is significantly increased endothelial dysfunction and systemic inflammation, which showed a positive correlation with disease severity. Thus, the markers of endothelial dysfunction such as ADMA and ANGPTL2 can be used as predictors of CVD risk in CKD.

Atherosclerotic-nephropathy: an updated narrative review

The increased prevalence of chronic kidney disease (CKD) in elderly patients recognizes, as main cause, the long-term exposure to atherosclerosis and hypertension. Chronic ischemic damage due to critical renal arterial stenosis induces oxidative stress and intra-renal inflammation, resulting in fibrosis and microvascular remodelling, that is the histological picture of atherosclerotic renal vascular disease (ARVD). The concomitant presence of a long history of hypertension may generate intimal thickening and luminal narrowing of renal arteries and arterioles, glomerulosclerosis, interstitial fibrosis and tubular atrophy, more typically expression of hypertensive nephropathy. These complex mechanisms contribute to the development of CKD and the progression to End Stage Kidney Disease. In elderly CKD patients, the distinction among these nephropathies may be problematic; therefore, ischemic and hypertensive nephropathies can be joined in a unique clinical syndrome defined as atherosclerotic nephropathy. The availability of novel diagnostic procedures, such as intra-vascular ultrasound and BOLD-MRI, in addition to traditional imaging, have opened new scenarios, because these tools allow to identify ischemic lesions responsive to renal revascularization. Indeed, although trials have deflated the role of renal revascularization on the renal outcomes, it should be still used to avoid dialysis initiation and/or to reduce blood pressure in selected elderly patients at high risk. Nonetheless, lifestyle modifications (smoking cessation, increased physical activity), statins and antiplatelet use, as well as cautious use of renin-angiotensin system inhibitors, remain the main therapeutic approach aimed at slowing the renal damage progression. Mesenchymal stem cells and Micro-RNA are promising target of anti-fibrotic therapy, which might provide potential benefit in ARVD patients, though safety and efficacy profile in humans is unknown too.

The Epigenetic Landscape of Vascular Calcification: An Integrative Perspective

Vascular calcification (VC) is an important complication among patients of advanced age, those with chronic kidney disease, and those with diabetes mellitus. The pathophysiology of VC encompasses passive occurrence of physico-chemical calcium deposition, active cellular secretion of osteoid matrix upon exposure to metabolically noxious stimuli, or a variable combination of both processes. Epigenetic alterations have been shown to participate in this complex environment, through mechanisms including DNA methylation, non-coding RNAs, histone modifications, and chromatin changes. Despite such importance, existing reviews fail to provide a comprehensive view of all relevant reports addressing epigenetic processes in VC, and cross-talk between different epigenetic machineries is rarely examined. We conducted a systematic review based on PUBMED and MEDLINE databases up to 30 September 2019, to identify clinical, translational, and experimental reports addressing epigenetic processes in VC; we retrieved 66 original studies, among which 60.6% looked into the pathogenic role of non-coding RNA, followed by DNA methylation (12.1%), histone modification (9.1%), and chromatin changes (4.5%). Nine (13.6%) reports examined the discrepancy of epigenetic signatures between subjects or tissues with and without VC, supporting their applicability as biomarkers. Assisted by bioinformatic analyses blending in each epigenetic component, we discovered prominent interactions between microRNAs, DNA methylation, and histone modification regarding potential influences on VC risk.

Indoxyl Sulfate-induced Vascular Calcification is mediated through Altered Notch Signaling Pathway in Vascular Smooth Muscle Cells

Introduction: The aim of this study was to determine the role of Notch in indoxyl sulfate (IS)-induced vascular calcification (VC). Materials and methods: VC and expression of Notch-related and osteogenic molecules were examined in Dahl salt-sensitive (DS), DS hypertensive (DH), and DH IS-treated rats (DH+IS). The effects of IS on expression of Notch receptors, apoptotic activity, and calcification were examined in cultured aortic smooth muscle cells (SMCs). Results: Medial calcification was noted only in aortas and coronary arteries of DH+IS rats. Notch1, Notch3, and Hes-1 were expressed in aortic SMCs of all rats, but only weakly in the central areas of the media and around the calcified lesions in DH+IS rats. RT-PCR and western blotting of DH+IS rat aortas showed downregulation of Notch ligands, Notch1 and Notch3, downstream transcriptional factors, and SM22, and conversely, overexpression of osteogenic markers. Expression of Notch1 and Notch3 in aortic SMCs was highest in incubation under 500 μM IS for 24hrs, and then decreased time- and dose-dependently. Coupled with this decrease, IS increased caspase 3/7 activity and TUNEL-positive aortic SMCs. In addition, pharmacological Notch signal inhibition with DAPT induced apoptosis in aortic SMCs. ZVAD, a caspase inhibitor abrogated IS-induced and DAPT-induced in vitro vascular calcification. Knockdown of Notch1 and Notch3 cooperatively increased expression of osteogenic transcriptional factors and decreased expression of SM22. Conclusion: Our results suggested that IS-induced VC is mediated through suppression of Notch activity in aortic SMCs, induction of osteogenic differentiation and apoptosis.

The Role of Matrix Gla Protein (MGP) in Vascular Calcification

Matrix Gla protein (MGP) is a vitamin K-dependent protein, which is synthesized in bone and many other mesenchymal cells, which is also highly expressed by vascular smooth muscle cells (VSMCs) and chondrocytes. Numerous studies have confirmed that MGP acts as a calcification-inhibitor although the mechanism of action is still not fully understood. The modulation of tissue calcification by MGP is potentially regulated in several ways including direct inhibition of calcium-phosphate precipitation, the formation of matrix vesicles (MVs), the formation of apoptotic bodies (ABs), and trans-differentiation of VSMCs. MGP occurs as four species, i.e. fully carboxylated (cMGP), under-carboxylated, i.e. poorly carboxylated (ucMGP), phosphorylated (pMGP), and non-phosphorylated (desphospho, dpMGP). ELISA methods are currently available that can detect the different species of MGP. The expression of the MGP gene can be regulated via various mechanisms that have the potential to become genomic biomarkers for the prediction of vascular calcification (VC) progression. VC is an established risk factor for cardiovascular disease and is particularly prevalent in those with chronic kidney disease (CKD). The specific action of MGP is not yet clearly understood but could be involved with the functional inhibition of BMP-2 and BMP-4, by blocking calcium crystal deposition and shielding the nidus from calcification.

Diagnostic Tests for Vascular Calcification

Vascular calcification (VC) is the heterogeneous endpoint of multiple vascular insults, which varies by arterial bed, the layer of the arterial wall affected, and is propagated by diverse cellular and biochemical mechanisms. A variety of in vivo and ex vivo techniques have been applied to the analysis of VC in preclinical studies, but clinical examination has principally relied on a number of noninvasive and invasive imaging modalities for detection and quantitation. Most imaging methods suffer from suboptimal spatial resolution, leading to the inability to distinguish medial from intimal VC and insufficient sensitivity to detect microcalcifications that are indicative of active mineral deposition and of vulnerable plaques which may be prone to rupture. Serum biomarkers lack specificity for VC and cannot discriminate pathology. Overall, uncertainties surrounding the sensitivity and specificity of different VC testing modalities, the absence of a clear cause-effect relationship, and lack of any evidence-based diagnostic or therapeutic protocols in relation to VC testing in chronic kidney disease has yielded weak or ungraded recommendations for their use in clinical practice. While VC is recognized as a key manifestation of chronic kidney disease-mineral and bone disorder and those with an increasing burden of VC are considered to be at higher cardiovascular risk, routine screening is not currently recommended.

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

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

Arterial Calcification on Wrist Radiographs May Suggest Need for Evaluation of Atherosclerosis in Asymptomatic Individuals

Asymptomatic individuals with significant coronary artery disease (CAD) are at risk for unanticipated cardiac events including myocardial infarction (MI). Laboratory studies, stress tests, and coronary artery imaging including coronary artery calcium (CAC) scoring evaluate at-risk individuals. Hand and wrist x-rays demonstrating significant arterial wall calcification may provide an additional means to identify asymptomatic individuals at risk for cardiac events. Here we report a case series of patients without known cardiac disease who demonstrated significant calcium deposits in the radial and/or ulnar arteries in radiographs performed for evaluation of their hand conditions. Each series patient was subsequently found to have calcification on coronary artery imaging and an elevated risk of future cardiac events. Our series suggests that peripheral arterial calcifications observed by radiologists and hand specialists may warrant systemic evaluation for atherosclerosis in other areas of the body.

Bilateral Lower Limb Disabling Claudication in a Young Man: A Case of Mönckeberg’s Arteriosclerosis

Mönckeberg’s arteriosclerosis, also called medial calcific sclerosis or Mönckeberg’s sclerosis, is a form of vessel hardening due to increased calcium deposits in the tunica media layer. There is disagreement over its clinical significance and aetiology and its relation to atherosclerosis and vascular calcification. Its clinical presentations and treatment are still debated. More effort should be directed on attempting to distinguish between atherosclerotic lesions and Mönckeberg’s lesions on the basis of age, location and the pattern of calcifications where there is considerable overlap between intimal or medial and involvement of the internal elastic lamina border between those planes. In-depth research is still needed to create consensus guidelines for the diagnosis and management of this condition. This article includes a review of the literature and a case report of a 22-year-old man with the condition.

Mönckeberg’s arteriosclerosis: a possible reason for non-use of radial conduit

We report the case of a 73-year-old man with diffuse calcification in both upper and lower limb arteries. This condition, termed Mönckeberg’s arteriosclerosis, was accompanied by three-vessel disease needing coronary artery bypass grafting. The diagnosis of arteriosclerosis was further verified by histopathology. The use of radial artery for coronary artery bypass grafting was prevented due to the heavily calcified nature of the vessel. Saphenous veins were harvested for non-left anterior descending arteries. Coexistence of Mönckeberg’s arteriosclerosis and atherosclerosis is possible and it affects the surgeon’s preference in conduit selection.

Vein conduit for end-to-side anastomosis of a calcified vessel in lower extremity free flap reconstruction

BACKGROUND

As the microsurgical and interventional revascularization techniques are evolving, traditionally amputated limbs are now challenged to salvage. However, a calcified recipient vessel is a common but challenging problem encountered in lower extremity reconstruction.

METHODS

An end-to-side anastomosis of a vein graft (1.5-3.5 cm in length) was performed to the recipient vessel when it was difficult to clamp the recipient vessel near the defect because of the inelastic and hard vessel wall. The vascular clamp was applied to the vein graft, and the flap's pedicle was anastomosed to the vein graft.

RESULTS

A total of 18 free flaps (10 ALT cases, 4 TDAP cases, 2 PAP cases, and 2 SCIP cases) were anastomosed with a bridge vein graft to the heavily calcified recipient vessels (7 ATA cases, 3 PTA cases, 7 DPA cases, and 1 MPA case). Overall flap survival rate was 83.3%. Limb salvage rate was 93.7%, and anastomosis patency rate was 94.4% CONCLUSION: Vein conduit in an end-to-side anastomosis of severely calcified recipient vessels shows a reasonable limb salvage rate. It acts as a buffer, which makes microscopic vessel manipulation easier. If vessel calcification is the only drawback for a free flap reconstruction, then a vein graft needs to be prepared instead of an amputation. This method may extend the surgical option to more high-risk patients in lower extremity microsurgical reconstruction and increase the limb salvage rate.

Rare Case of Floating Intimal Flap Associated with Atheromatous Carotid Plaque

BACKGROUND

A mobile carotid plaque can be detected by duplex ultrasonography and is a high-risk factor for embolic stroke.

CASE DESCRIPTION

We herein present a case involving an 80-year-old man with an asymptomatic carotid floating flap diagnosed by duplex ultrasonography and treated with carotid endarterectomy. Intraoperatively, an ulceration was found immediately proximal to the neck of the floating flap, and the shape and size of the ulceration were quite similar to those of the floating flap. In a histopathologic examination of the specimen resected by carotid endarterectomy, the plaque lacked the internal elastic lamina (IEL) at the ulceration, calcification was observed in the plaque and medial layer at the ulceration, and the floating flap consisted of the IEL accompanied by calcification, fibrin, and foamy cells.

CONCLUSIONS

Progression of the atheroma and Mönckeberg sclerosis might have affected disruption of the IEL, causing the IEL to finally peel off. A floating intimal flap accompanied by an atheroma without intraplaque hemorrhage is a rare cause of mobile plaque formation. This type of mobile plaque might not be dissolved by medical treatment alone. In such cases, surgical treatment is a suitable therapeutic choice to prevent stroke.

Serum endostatin level as a marker for coronary artery calcification in type 2 diabetic patients

Objective

To assess the relationship between serum endostatin (ES) and coronary artery calcification (CAC) in type 2 diabetic (T2DM) patients.

Methods

The study included 110 participants with coronary artery disease (CAD); 55 with T2DM, for serum ES levels by enzyme-linked immunosorbent assay and CAC by contrast-enhanced spiral computed tomography (CT).

Results

Mean serum ES value was 66.54 ng/mL [95% confidence interval (CI), 61.77-71.32 ng/mL]. Serum ES levels positively correlated with Agatston score index [ASI; r = 0.701, p < 0.001; high sensitive C-reactive protein (hs-CRP) r = 0.783, p < 0.001]. On multiple regression analysis, the highest three ES quartiles (2, 3, and 4) were related to ASI in diabetic patients, adjusted ES level was an independent predictor of CAD [odds ratio (OR) = 1.065; 95% CI, 1.008-1.126; p = 0.026] and for the number of coronary vessels affected (OR = 1.089; 95% CI, 1.018-1.164; p = 0.013) in T2DM patients. Receiver operating characteristics (ROC) analysis showed serum ES at a cutoff value of 86.5 ng/mL can predict the risk of CAC in T2DM, with a sensitivity of 74.1%, specificity of 71.4%, p < 0.001 and area under curve (AUC) of 0.776.

Conclusion

Measurement of serum ES levels can improve diagnosis of CAC and could be useful as a high sensitive marker for the presence and progression of atherosclerosis in T2DM patients.

Risk factors and utility of maximum carotid intima-media thickness as a surrogate marker for coronary artery stenosis

Background

This study investigated the factors associated with coronary artery stenosis in outpatients. Furthermore, the usefulness of maximum carotid intima–media thickness (maximum-IMT) as a surrogate marker of coronary artery stenosis was evaluated.

Methods

We conducted a single-center retrospective study. A total of 601 outpatients (338 males; 263 females; mean age, 69.8±10.0 years) who underwent coronary computed tomography angiography between April 2006 and March 2012 were analyzed. The associations between coronary artery stenosis (≥75%) as determined by coronary computed tomography angiography and clinical and laboratory parameters were evaluated by multivariate logistic regression. Validation of maximum-IMT as measured by ultrasonography as a surrogate marker of coronary artery stenosis was analyzed by receiver operating characteristic (ROC) curve analysis.

Results

The estimated glomerular filtration rate (eGFR: mL/min/1.73 m²) (odds ratio [OR] 0.985, p<0.01), diabetes mellitus (OR 1.98, p<0.05), and maximum-IMT (mm) (OR 1.76, p<0.01) were significantly associated with coronary artery stenosis (≥75%). In analysis of each group categorized by identified factors, such as renal impairment (eGFR <60 mL/min/1.73 m²) and diabetes mellitus, the ROC curve of maximum-IMT was significant in the group of patients with diabetes mellitus without renal impairment (p<0.01) (cutoff value of maximum-IMT, 2.0 mm; sensitivity, 0.74; and specificity, 0.54) but not in other groups.

Conclusion

Renal impairment, diabetes mellitus, and increased maximum-IMT may be significant risk factors of coronary artery stenosis. Maximum-IMT as measured by ultrasonography may be a useful surrogate marker for coronary artery stenosis in patients with diabetes mellitus without renal impairment but not in other patients.

Prevalence of Calcification in Human Femoropopliteal Arteries and its Association with Demographics, Risk Factors, and Arterial Stiffness

OBJECTIVE

Arterial calcification and stiffening increase the risk of reconstruction failure, amputation, and mortality in patients with peripheral arterial disease, but underlying mechanisms and prevalence are unclear.

APPROACH AND RESULTS

Fresh human femoropopliteal arteries were obtained from n=431 tissue donors aged 13 to 82 years (mean age, 53±16 years) recording the in situ longitudinal prestretch. Arterial diameter, wall thickness, and opening angles were measured optically, and stiffness was assessed using planar biaxial extension and constitutive modeling. Histological features were determined using transverse and longitudinal Verhoeff-Van Gieson and Alizarin stains. Medial calcification was quantified using a 7-stage grading scale and was correlated with structural and mechanical properties and clinical characteristics. Almost half (46%) of the femoropopliteal arteries had identifiable medial calcification. Older arteries were more calcified, but small calcium deposits were observed in arteries as young as 18 years old. After controlling for age, positive correlations were observed between calcification, diabetes mellitus, dyslipidemia, and body mass index. Tobacco use demonstrated a negative correlation. Calcified arteries were larger in diameter but had smaller circumferential opening angles. They were also stiffer longitudinally and circumferentially and had thinner tunica media and external elastic lamina with more discontinuous elastic fibers.

CONCLUSIONS

Although aging is the dominant risk factor for femoropopliteal artery calcification and stiffening, these processes seem to be linked and can begin at a young age. Calcification is associated with the presence of certain risk factors and with elastic fiber degradation, suggesting overlapping molecular pathways that require further investigation.

Mechanisms of Arterial Calcification: The Role of Matrix Vesicles

Vascular calcification is related to vascular diseases, for example, atherosclerosis, and its comorbidities, such as diabetes and chronic kidney disease. In each condition, a distinctive histological pattern can be recognised that may influence technical choices, possible intra-operative complications, and procedure outcomes, no matter if the intervention is performed by open or endovascular means. This review considers the classification and initiating mechanisms of vascular calcification. Dystrophic and metastatic calcifications, Monckeberg's calcification, and genetic forms are firstly outlined, followed by their alleged initiation mechanisms; these include (a) ineffective macrophage efferocytosis; (b) ectopic osteogenesis driven by modified resident or circulating osteoprogenitors. As in physiological bio-mineralisation, active calcification starts with the deposition of cell derived matrix vesicles into the extracellular matrix. To substantiate this belief, an in depth ultra-structural documentation of hydroxyapatite crystal deposition on such vesicles is provided in an ex-vivo human vascular cell model. Revealing the vesicle composition and phenotype in normal and pathological vascular conditions will be essential for the development of new therapeutic strategies, in order to prevent and treat vascular calcification.

Calcification Propensity of Serum is Independent of Excretory Renal Function

Vascular calcification is a component of cardiovascular disease, which is leading cause of death in patients with chronic kidney disease (CKD). A functional assay (T50-test) measuring the propensity of human serum to calcify associates with mortality and cardiovascular events in CKD patients. Calcification propensity is known to increase with CKD stage. We investigated whether the T50 readout is directly dependent on excretory kidney function (eGFR) or rather explained by deranged parameters of bone and mineral metabolism in the course of CKD. T50, along with markers implicated in calcification and mineral metabolism, were measured in a cross-sectional cohort of 118 patients with CKD stage 1–5. Associations of T50 with measured parameters were analysed and partial correlations performed to test to which extent the association of T50 with eGFR can be attributed to variation of these parameters. T50 correlates with eGFR, but serum levels of phosphate and calcium largely explain this association. Phosphate, magnesium, fetuin A, albumin, bicarbonate, and serum cross-laps but not Parathyroid Hormone or Fibroblast Growth Factor 23 are associated with T50 in multivariate adjusted models. These findings indicate that T50 values depend mainly on the concentration of promoters and inhibitors of calcification in serum, but not excretory kidney function.

Cardiovascular Risk Factors and Markers of Atherosclerosis in Stable Kidney Transplant Recipients

BACKGROUND

There is limited evidence regarding the risk factors influencing vascular injury in kidney transplant recipients, except for accelerated vasculopathy and endothelial dysfunction in the pre-transplantation period of end-stage renal failure. Therefore, we performed a cross-sectional study to evaluate the role of traditional and novel or potential nontraditional risk factors in vascular and endothelial dysfunction in a cohort of stable kidney transplant recipients.

METHODS

One hundred forty-two kidney transplant recipients at 8.4 ± 1.8 years after transplantation were enrolled into the study. Different markers of vascular injury, such as carotid intima-media thickness (IMT), pulse wave velocity (PWV), and peripheral arterial tonometry (PAT), were assessed. Inflammatory markers, oxidative stress and endothelial function surrogate markers, adhesion molecules, and parathormone and osteoprotegerin levels were measured.

RESULTS

Among traditional risk factors, only age, pre-transplantation diabetes, left ventricular hypertrophy (LVH) and cardiovascular disease (CVD) were related to increased IMT and PWV, whereas PAT values were significantly decreased only in diabetics and patients with CVD and were similar in patients with and without LVH. In multivariate regression analysis, IMT was explained by age, previous CVD episodes, and higher high-sensitivity C-reactive protein levels, and PWV by age and pre-transplantation diabetes. The regression analysis failed to find any significant explanatory variables for PAT.

CONCLUSIONS

1. In stable kidney transplant recipients, age, pre-transplantation diabetes, previous cardiovascular episode, and systemic microinflammation were predictors of vascular injury. 2. PAT is poorly associated with traditional CV risk factors and does not correspond with levels of biochemical markers of endothelial dysfunction in those patients.

Targeting Immunity in End-Stage Renal Disease

BACKGROUND

Despite the stable incidence of end-stage renal disease (ESRD), it continues to be associated with an unacceptably high cardiovascular risk.

SUMMARY

ESRD is characterized by enhanced oxidative stress and severe inflammation, which boost cardiovascular risk, thus increasing cardiovascular-associated mortality rate. While substantial effort has been made in the technological innovation of dialytic techniques, few significant advances have been made to reduce inflammation in patients with ESRD. Indeed, this contrasts with the extensive scientific breakthroughs made in the basic field of science in targeting inflammation. There is thus a pressing need for clinical trials to test the effect of reducing inflammation in patients with ESRD. Here, we will revisit the negative effect of ESRD on inflammation and explore the impact of enhanced inflammation on cardiovascular outcomes and survival in patients with ESRD. Finally, we will discuss the need for clinical trials that target inflammation in ESRD, as well as weigh potential disadvantages and offer novel innovative approaches. Key Message: We will try to understand why the issue of inflammation has not been successfully addressed thus far in patients with ESRD, while at the same time weighing the potential disadvantages and offering novel innovative approaches for targeting inflammation in patients with ESRD.

Hypertension, type IV cardiorenal syndrome and chronic kidney disease: Pathophysiological and therapeutical approach

Hypertension represent one of the most important comorbid factors in chronic kidney disease (CKD) patients and its prevalence increases from 65% to 95% according to glomerular filtration rate decline. CKD patients need to maintain their blood pressure levels into 130/80 mmHg according to most recent guidelines. Despite of many therapeutic agents, achievement of ideal blood pressure levels remains so far from the ideal ones. Hypertensive disease represent most important risk factor to develop a type IV cardiorenal syndrome, while prevalence of end stage renal disease is still raising and it represents worldwide epidemiological challenge. Correct management of hypertensive disease can obtain better control on CKD progression.

Modified Lipids and Lipoproteins in Chronic Kidney Disease: A New Class of Uremic Toxins

Chronic kidney disease (CKD) is associated with an enhanced oxidative stress and deep modifications in lipid and lipoprotein metabolism. First, many oxidized lipids accumulate in CKD and were shown to exert toxic effects on cells and tissues. These lipids are known to interfere with many cell functions and to be pro-apoptotic and pro-inflammatory, especially in the cardiovascular system. Some, like F2-isoprostanes, are directly correlated with CKD progression. Their accumulation, added to their noxious effects, rendered their nomination as uremic toxins credible. Similarly, lipoproteins are deeply altered by CKD modifications, either in their metabolism or composition. These impairments lead to impaired effects of HDL on their normal effectors and may strongly participate in accelerated atherosclerosis and failure of statins in end-stage renal disease patients. This review describes the impact of oxidized lipids and other modifications in the natural history of CKD and its complications. Moreover, this review focuses on the modifications of lipoproteins and their impact on the emergence of cardiovascular diseases in CKD as well as the appropriateness of considering them as actual mediators of uremic toxicity.