The functional role of cellular senescence during vascular calcification in chronic kidney disease

Vascular calcification (VC) has emerged as a key predictor of cardiovascular events in patients with chronic kidney disease (CKD). In recent years, an expanding body of research has put forth the concept of accelerated vascular aging among CKD patients, highlighting the significance of vascular cells senescence in the process of VC. Within the milieu of uremia, senescent vascular endothelial cells (VECs) release extracellular microvesicles (MV) that promote vascular smooth muscle cells (VSMCs) senescence, thereby triggering the subsequent osteogenic phenotypic switch and ultimately contributing to the VC process. In addition, senescent vascular progenitor or stem cells with diminished ability to differentiate into VECs and VSMCS, compromise the repair of vascular integrity, on the other hand, release a cascade of molecules associated with senescence, collectively known as the senescence-associated secretory phenotype (SASP), perpetuating the senescence phenomenon. Furthermore, SASP triggers the recruitment of monocytes and macrophages, as well as adjacent VECs and VSMCs into a pro-adhesive and pro-inflammatory senescent state. This pro-inflammatory microenvironment niche not only impacts the functionality of immune cells but also influences the differentiation of myeloid immune cells, thereby amplifying the reduced ability to effectively clear senescent cells of senescent macrophages, promoted calcification of VSMCs. The objective of this paper is to provide a comprehensive review of the contribution of vascular cell senescence to the emergence and advancement of VC. Gaining a comprehensive understanding of the involvement of cellular senescence within the vessel wall is pivotal, especially when it comes to its intersection with VC. This knowledge is essential for advancing groundbreaking anti-aging therapies, aiming to effectively mitigate cardiovascular diseases.

PRMT3 methylates HIF-1α to enhance the vascular calcification induced by chronic kidney disease

BACKGROUND

Medial vascular calcification is commonly identified in chronic kidney disease (CKD) patients and seriously affects the health and life quality of patients. This study aimed to investigate the effects of protein arginine methyltransferase 3 (PRMT3) on vascular calcification induced by CKD.

METHODS

A mice model of CKD was established with a two-step diet containing high levels of calcium and phosphorus. Vascular smooth muscle cells (VSMCs) were subjected to β-glycerophosphate (β-GP) treatment to induce the osteogenic differentiation as an in vitro CKD model.

RESULTS

PRMT3 was upregulated in VSMCs of medial artery of CKD mice and β-GP-induced VSMCs. The inhibitor of PRMT3 (SGC707) alleviated the vascular calcification and inhibited the glycolysis of CKD mice. Knockdown of PRMT3 alleviated the β-GP-induced osteogenic transfomation of VSMCs by the repression of glycolysis. Next, PRMT3 interacted with hypoxia-induced factor 1α (HIF-1α), and the knockdown of PRMT3 downregulated the protein expression of HIF-1α by weakening its methylation. Gain of HIF-1α reversed the PRMT3 depletion-induced suppression of osteogenic differentiation and glycolysis of VSMCs.

CONCLUSION

The inhibitory role of PRMT3 depletion was at least mediated by the regulation of glycolysis upon repressing the methylation of HIF-1α.

Establishment and evaluation of a nomogram prediction model for the risk of vascular calcification in stage 5 chronic kidney disease patients

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD) that has a detrimental effect on patients' survival and prognosis. The aim of this study was to develop and validate a practical and reliable prediction model for VC in CKD5 patients. The medical records of 544 CKD5 patients were reviewed retrospectively. Multivariate logistic regression analysis was used to identify the independent risk factors for vascular calcification in patients with CKD5 and then created a nomogram prediction model. The area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow test, and decision curve analysis (DCA) were used to assess model performance. The patients were split into groups with normal and high serum uric acid levels, and the factors influencing these levels were investigated. Age, BUN, SUA, P and TG were independent risk factors for vascular calcification in CKD5 patients in the modeling group (P < 0.05). In the internal validation, the results of model showed that the AUC was 0.917. No significant divergence between the predicted probability of the nomogram and the actual incidence rate (x2 = 5.406, P = 0.753) was revealed by the calibration plot and HL test, thus confirming that the calibration was satisfactory. The external validation also showed good discrimination (AUC = 0.973). The calibration chart and HL test also demonstrated good consistency. Besides, the correlation analysis of serum uric acid levels in all CKD5 patients revealed that elevated uric acid levels may be related to gender, BUN, P, and TG.

Association between hemoglobin A1c and abdominal aortic calcification: results from the National Health and Nutrition Examination Survey 2013-2014

BACKGROUND

Hemoglobin A1c (HbA1c), a "gold standard" for the assessment of glycemic control, was associated with an increased risk of cardiovascular disease and coronary artery calcification. However, its effects on abdominal aortic calcification (AAC) are uncertain. The present study comprehensively investigated the association between HbA1c and AAC in the 2013-2014 National Health and Nutrition Examinations Surveys.

METHODS

Among 1,799 participants ≥ 40 years, dual-energy X-ray absorptiometry-derived AAC was quantified using the Kauppila score (AAC-24). Severe AAC was defined as a total AAC-24 > 6. Weighted linear regression models and logistic regression models were used to determine the effects of HbA1c on AAC. The restricted cubic spline model was used for the dose-response analysis.

RESULTS

The mean AAC-24 of participants was 1.3, and 6.7% of them suffered from severe AAC. Both AAC-24 and the prevalence of severe AAC increased with the higher tertile of HbA1c (P < 0.001). Elevated HbA1c levels would increase the AAC-24 (β = 0.73, 95% CI: 0.30-1.16) and the risk of severe AAC (OR = 1.63, 95% CI: 1.29-2.06), resulting in nearly linear dose-response relationships in all participants. However, this positive correlation were not statistically significant when participants with diabetes were excluded. Furthermore, subgroup analysis showed significant interactions effect between HbA1c and hypertension on severe AAC with the OR (95% CI) of 2.35 (1.62-3.40) for normotensives and 1.39 (1.09-1.79) for hypertensives (P for interaction = 0.022).

CONCLUSION

Controlling HbA1c could reduce AAC scores and the risk of severe AAC. Glycemic management might be a component of strategies for preventing AAC among all participants, especially normotensives.

Orbital atherectomy safety and efficacy: A comparative analysis of ostial versus non-ostial calcified coronary lesions

BACKGROUND

The safety and efficacy of coronary orbital atherectomy (OA) for treatment of ostial lesions are not yet fully established. We sought to evaluate (OA) treatment of severely calcified ostial and non-ostial lesions.

METHODS

A retrospective analysis of subjects treated with OA for severely calcified ostial and non-ostial lesions, at the Mount Sinai Medical Center, Miami Beach, Florida (MSMCMB) from January 2014 to September 2020, was completed. Study baseline characteristics, lesion and vessel characteristics, procedural outcomes, and in-hospital major adverse cardiovascular events (MACE) were analyzed and compared.

RESULTS

A total of 609 patients that underwent PCI with OA were identified. The majority of patients (81.9 %) had non-ostial lesions, while 16.6 % had ostial lesions (of which 2.8 % classified as aorto-ostial) and 1.5 % had unknown lesion anatomy. The mean age of the overall cohort was 74.0 ± 9.3 years, and 63.5 % were male. All patients received drug-eluting stent (DES) placement, and the overall freedom from MACE was 98.5 %, with no significant difference observed between the ostial and non-ostial groups. The freedom from cardiac death and MI was also similar between the two groups. There were low rates of bleeding complications and severe angiographic complications, and no persistent slow flow/no reflow was reported.

CONCLUSIONS

This study demonstrated no significant differences in in-hospital MACE outcomes between patients with ostial versus non-ostial lesions, indicating that OA is a safe and effective treatment option for both lesion types, including those classified as aorto-ostial.

Phosphonoformic acid reduces hyperphosphatemia-induced vascular calcification via Pit-1

OBJECTIVE

This study aimed to examine the mechanism of hyperphosphatemia-induced vascular calcification (HPVC).

METHODS

Primary human aortic smooth muscle cells and rat aortic rings were cultured in Dulbecco's modified Eagle's medium supplemented with 0.9 mM or 2.5 mM phosphorus concentrations. Type III sodium-dependent phosphate cotransporter-1 (Pit-1) small interfering RNA and phosphonoformic acid (PFA), a Pit-1 inhibitor, were used to investigate the effects and mechanisms of Pit-1 on HPVC. Calcium content shown by Alizarin red staining, expression levels of Pit-1, and characteristic molecules for phenotypic transition of vascular smooth muscle cells were examined.

RESULTS

Hyperphosphatemia induced the upregulation of Pit-1 expression, facilitated phenotypic transition of vascular smooth muscle cells, and led to HPVC in cellular and organ models. Treatment with Pit-1 small interfering RNA or PFA significantly inhibited Pit-1 expression, suppressed phenotypic transition, and attenuated HPVC.

CONCLUSIONS

Our findings suggest that Pit-1 plays a pivotal role in the development of HPVC. The use of PFA as a Pit-1 inhibitor has the potential for therapeutic intervention in patients with HPVC. However, further rigorous clinical investigations are required to ensure the safety and efficacy of PFA before it can be considered for widespread implementation in clinical practice.

Effect of iron administration on the aortic iron content and vascular calcification in phosphorus-loaded chronic kidney disease rats

BACKGROUND

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD) and could be related to oxidative stress. Vascular calcification (VC) has been established as a critical risk factor for accelerated CVD. In CKD, phosphorus (Pi), iron (Fe) and Nrf2 are modulators of VC and important agonists and antagonists of oxidative stress. The aim of this study was to determine whether Fe administration, which is commonly used to treat renal anemia, affects aortic Fe overload and VC, and whether Nrf2 and its related genes, ferritin H and HIF-1α, are involved in the development of VC.

METHODS

A CKD model was created in rats by administering adenine and simultaneously feeding a high-Pi diet. In addition to control and CKD rats without Fe administration (No-Fe group), Fe was administered orally (PO-Fe group) or intraperitoneally (IP-Fe group) to CKD animals to clarify the effects of Fe administration on the aortic Fe and calcium (Ca) contents and the involvement of Nrf2 and its induced antioxidative proteins, ferritin H and HIF-1α, in VC.

RESULTS

The aortic Fe content increased significantly in the IP-Fe group, which was closely correlated with liver HAMP (hepcidin) expression in all animals. Fe administration had no significant effect on the aortic Ca and Pi contents regardless of the route of Fe administration. The aortic mRNA level of Nrf2 was significantly increased in the IP-Fe group and correlated with serum Pi levels and aortic Fe contents, which could respond to oxidative stress. Notably, the mRNA level of Nrf2 was also significantly correlated with the mRNA levels of ferritin H and HIF-1α. Since we could not measure Nrf2 protein levels in this study, we confirmed the upregulation of HMOX1 and NQO1 mRNA expression in parallel with Nrf2 mRNA.

CONCLUSION

Parenteral Fe administration increased aortic Fe in parallel with the liver HAMP mRNA level but did not affect VC. Aortic Nrf2 mRNA levels correlated significantly with aortic Fe and serum Pi levels and with aortic mRNA levels of ferritin H and HIF-1α as well as HMOX1 and NQO1.

Effects of sodium thiosulfate on serum calcification factors in patients undergoing maintenance hemodialysis

OBJECTIVE

To investigate the effect of sodium thiosulfate (STS) on serum calcification factors in patients undergoing maintenance hemodialysis.

METHODS

Forty-four Patients were randomly divided into control group (n = 22) and observation group (n = 22) by envelope method (block 4 randomization). The control group received routine treatment while observation group was treated with STS on the basis of routine treatment. The biochemical indicators, including BUN, UA, SCr, Ca2+ , P3- , calcium-phosphorus product, PTH, hs-CRP, TG, TC, HDL, LDL, and serum calcification factor MGP, FA, FGF-23, and OPG levels were compared before and after treatment.

RESULTS

Control group had no statistically significant difference in the levels of vascular calcification factors MGP, FA, FGF-23, and OPG before and after treatment (p > 0.05). Whereas observation group had higher levels of MGP and FA, and lower levels of FGF-23 and OPG after treatment than before treatment (p < 0.05). The levels of MGP and FA in observation group were higher than those in control group, and FGF-23 and OPG were lower than those in control group (p < 0.05).

CONCLUSION

It is speculated that sodium thiosulfate can alleviate the progression of vascular calcification by changing the levels of calcification factors.

Associated factors of osteoporosis and vascular calcification in patients awaiting kidney transplantation

INTRODUCTION

Pretransplant osteoporosis and vascular calcification probably increase the risk of fractures and cardiovascular events after kidney transplantation. In the present study, we investigated the related risk factors of osteoporosis and vascular calcification among end-stage renal disease (ESRD) patients awaiting kidney transplantation.

METHODS

A total of 221 ESRD patients (age, 43.4 ± 14.3 years; 125 males and 96 females; median dialysis duration, 61.0 m) awaiting kidney transplantation were enrolled in this cross-sectional study. Serum levels of bone turnover markers and intact parathyroid hormone (iPTH) were analyzed from fasting morning blood samples. Dual-energy X-ray absorptiometry was used to measure bone mineral density (BMD). Vascular calcification was evaluated by lateral abdominal radiography and plain radiographic films of the pelvis and hands.

RESULTS

The osteoporosis prevalence was 27.6% in this cohort of kidney transplantation candidates, and the prevalence of vascular calcification was 51.1%. The related factors for osteoporosis and vascular calcification were similar and included older age, longer dialysis duration, parathyroid hyperplasia, and higher levels of iPTH and bone turnover markers. In the multivariable regression model, age and iPTH were independent risk predictors of both vascular calcification and osteoporosis. There were strong, positive correlations between iPTH and all bone turnover markers. The moderate and severe hyperparathyroidism (iPTH 600-1499 pg/ml and iPTH 1500 pg/ml) were related to reduced serum albumin and hemoglobin levels.

CONCLUSION

The involvement of high iPTH levels in vascular calcification, osteoporosis, and malnutrition indicated the need of treating hyperparathyroidism early in patients awaiting kidney transplantation. Prospective studies are needed to further examine the utility of bone turnover markers.

Leucine-Rich Alpha-2 Glycoprotein 1 Accumulates in Complicated Atherosclerosis and Promotes Calcification

Atherosclerosis is the primary cause of cardiovascular disease. The development of plaque complications, such as calcification and neo-angiogenesis, strongly impacts plaque stability and is a good predictor of mortality in patients with atherosclerosis. Despite well-known risk factors of plaque complications, such as diabetes mellitus and chronic kidney disease, the mechanisms involved are not fully understood. We and others have identified that the concentration of circulating leucine-rich α-2 glycoprotein 1 (LRG1) was increased in diabetic and chronic kidney disease patients. Using apolipoprotein E knockout mice (ApoE-/-) (fed with Western diet) that developed advanced atherosclerosis and using human carotid endarterectomy, we showed that LRG1 accumulated into an atherosclerotic plaque, preferentially in calcified areas. We then investigated the possible origin of LRG1 and its functions on vascular cells and found that LRG1 expression was specifically enhanced in endothelial cells via inflammatory mediators and not in vascular smooth muscle cells (VSMC). Moreover, we identified that LRG1 was able to induce calcification and SMAD1/5-signaling pathways in VSMC. In conclusion, our results identified for the first time that LRG1 is a direct contributor to vascular calcification and suggest a role of this molecule in the development of plaque complications in patients with atherosclerosis.

L-type calcium ion channel-mediated activation of autophagy in vascular smooth muscle cells via thonningianin A (TA) alleviates vascular calcification in type 2 diabetes mellitus

Vascular calcification (VC) is associated with increased morbidity and mortality, especially among people with type 2 diabetes mellitus (T2DM). The pathogenesis of vascular calcification is incompletely understood, and until now, there have been no effective therapeutics for vascular calcification. The L-type calcium ion channel in the cell membrane is vital for Ca2+ influx. The effect of L-type calcium ion channels on autophagy remains to be elucidated. Here, the natural compound thonningianin A (TA) was found to ameliorate vascular calcification in T2DM via the activation of L-type calcium ion channels. The results showed that TA had a concentration-dependent ability to decrease the transcriptional and translational expression of the calcification-related proteins runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2) and osteopontin (OPN) (P < 0.01) via ATG7-dependent autophagy in β-glycerophosphate (β-GP)- and high glucose (HG)-stimulated primary mouse aortic smooth muscle cells (MASMCs) and alleviate aortic vascular calcification in VitD3-stimulated T2DM mice. However, nifedipine, an inhibitor of L-type calcium ion channels, reversed TA-induced autophagy and Ca2+ influx in MASMCs. Molecular docking analysis revealed that TA was located in the hydrophobic pocket of Cav1.2 α1C and was mainly composed of the residues Ile, Phe, Ala and Met, which confirmed the efficacy of TA in targeting the L-type calcium channel of Cav1.2 on the cell membrane. Moreover, in an in vivo model of vascular calcification in T2DM mice, nifedipine reversed the protective effects of TA on aortic calcification and the expression of the calcification-related proteins RUNX2, BMP2 and OPN (P < 0.01). Collectively, the present results reveal that the activation of cell membrane L-type calcium ion channels can induce autophagy and ameliorate vascular calcification in T2DM. Thonningianin A (TA) can target and act as a potent activator of L-type calcium ion channels. Thus, this research revealed a novel mechanism for autophagy induction via L-type calcium ion channels and provided a potential therapeutic for vascular calcification in T2DM.

Vascular calcification progression and its association with mineral and bone disorder in kidney transplant recipients

BACKGROUND

The assessment and prevention of vascular calcification (VC) in kidney transplant recipients (KTRs) have not been systematically studied. We aimed to evaluate VC change one year after kidney transplantation (KT) and identify their influencing factors.

METHODS

95 KTRs (68 males; ages 40.2 ± 10.8 years) were followed one year after KT. Changes in bone mineral density (BMD) and bone metabolism biomarkers were assessed. Coronary artery calcification (CAC) and thoracic aortic calcification (TAC) were measured using 192-slice third-generation dual-source CT. The relationship between bone metabolism indicators and VC and the factors influencing VC were analyzed.

RESULTS

Postoperative estimated glomerular filtration rate was 79.96 ± 24.18 mL/min*1.73 m2. One year after KT, serum phosphorus, intact parathyroid hormone (iPTH), osteocalcin, type I collagen N-terminal peptide (NTx), type I collagen C-terminal peptide, and BMD decreased, 25-hydroxyvitamin D remained low, and VC increased. Post-CAC and TAC were negatively correlated with pre-femoral neck BMD, and TAC was positively correlated with post-calcium. CAC and TAC change were positively correlated with post-calcium and 25-hydroxyvitamin D. Increased CAC was positively associated with hemodialysis and pre-femoral neck osteopenia. CAC change was positively associated with prediabetes, post-calcium, and pre-CAC and negatively associated with preoperative and postoperative femoral neck BMD, and NTx change. Increased TAC was positively associated with age, prediabetes, preoperative parathyroid hyperplasia/nodule, post-calcium, and post-femoral neck osteopenia. TAC change was positively associated with age, diabetes, pre-triglyceride, pre-TAC, dialysis time, post-calcium and post-iPTH, and negatively associated with post-femoral neck BMD.

CONCLUSIONS

Mineral and bone disorders persisted, and VC progressed after KT, showing a close relationship.

[Coronary lithotripsy in calcified lesions: fragmented calcium]

Background

Complex calcified coronary lesions are a frequent finding during percutaneous coronary intervention, representing for decades a challenge and limitation in patients with indication of revascularization, due to suboptimal angiographic results, high incidence of perioperative complications and long-term adverse events despite the multiple strategies employed, such as the use of cutting balloon, high-pressure balloons or rotational or orbital atherectomy, interventions with limitations that have hindered its routine use, recently a new plaque modification technique known as coronary intravascular lithotripsy has burst into the treatment of this complex entity, which consists in the use of a specially modified balloon for the emission of pulsatile mechanical energy (sonic pressure waves) that allows modifying the calcified plate.

Clinical case

By presenting a series of clinical cases and reviewing the literature, our initial experience is presented, key elements are summarized and discussed in the understanding of this new intervention technique necessary for decision making.

Conclusion

Coronary intravascular lithotripsy is projected as a promising technique for the modification and preparation of superficial and deep calcified coronary lesions, through microfractures that allow the apposition and effective expansion of the stent, strategy that according to different trials (Disrupt CAD series, SOLSTICE assay) and records presents a high efficiency and good safety profile, data consistent with our initial experience.

Clinical Implication of Consistently Strict Phosphate Control for Coronary and Valvular Calcification in Incident Patients Undergoing Hemodialysis

AIMS

Serum phosphate control is crucial for the progression of vascular and valvular calcifications. Strict phosphate control is recently suggested; however, there is a lack of convincing evidence. Therefore, we explored the effects of strict phosphate control on vascular and valvular calcifications in incident patients undergoing hemodialysis.

METHODS

A total of 64 patients undergoing hemodialysis from our previous randomized controlled trial were included in this study. Coronary artery calcification score (CACS) and cardiac valvular calcification score (CVCS) were evaluated using computed tomography and ultrasound cardiography at baseline and 18 months after the initiation of hemodialysis. The absolute changes in CACS (ΔCACS) and CVCS (ΔCVCS) and the percent change in CACS (%ΔCACS) and CVCS (%ΔCVCS) were calculated. Serum phosphate level was measured at 6, 12, and 18 months after the initiation of hemodialysis. Moreover, phosphate control status was evaluated using the area under the curve (AUC) by the amount of time spent with a serum phosphate level of ≥ 4.5 mg/dL and the extent to which this threshold exceeded over the observation period.

RESULTS

ΔCACS, %ΔCACS, ΔCVCS, and %ΔCVCS were significantly lower in the low AUC group than in the high AUC group. ΔCACS and %ΔCACS were also significantly lower. ΔCVCS and %ΔCVCS tended to be lower in patients whose serum phosphate level never exceeded 4.5 mg/dL than in those whose serum phosphate level continuously exceeded 4.5 mg/dL. AUC significantly correlated with ΔCACS and ΔCVCS.

CONCLUSION

Consistently strict phosphate control may slow the progression of coronary and valvular calcifications in incident patients undergoing hemodialysis.

Intravascular lithotripsy compared to rotational atherectomy for the treatment of calcified distal left main coronary artery disease: A single center experience

BACKGROUND

The safety and efficacy of intravascular lithotripsy (IVL) for the treatment of calcified distal left main (LM) disease remains unclear, especially compared to rotational atherectomy (RA).

METHODS

We retrospectively analyzed the baseline clinical, angiographic, intravascular ultrasound (IVUS) characteristics and procedural outcomes of 107 patients who underwent distal LM percutaneous coronary intervention (PCI) with IVL (with or without adjunct atherectomy) versus RA alone for plaque modification before stenting at a single center between 2020 and 2022.

RESULTS

A total of 50 patients underwent calcium modification with IVL with or without adjunct atherectomy and 57 with RA only. The mean age was 73 years and with a high prevalence of diabetes (58.9%), chronic kidney disease (42.1%), prior revascularization (coronary artery bypass graft surgery [36.4%] or prior PCI [32.7%]). Acute coronary syndrome was the primary indication for PCI in over 50% of the patients in both groups. Medina 1-1-1 LM bifurcation disease was identified in 64% and 60% of the IVL and RA groups (p = 0.64) respectively. Final minimum stent area in distal LM (>8.2 mm2 ), ostial LAD (>6.3 mm2 ) and ostial LCX (>5.0 mm2 ) were achieved in 96%, 85% and 89% of cases treated with IVL respectively and 93%, 93% and 100% of cases treated with RA respectively (LM p = 1.00; LAD p = 0.62; LCX; p = 1.00 for difference between the two groups). Procedural success (technical success without in-hospital major adverse events) was achieved in 98% of the IVL group and 86% of the RA-only group (p = 0.04). There were eight procedural complications (flow-limiting dissection, perforation, or slow/no-reflow) in the RA group compared to four in the IVL group (NS), and one patient in the RA required salvaged mechanical support compared to none in the IVL group.

CONCLUSION

Plaque modification with coronary IVL appears to be efficacious and safe for the treatment of severely calcified distal LM lesions compared to RA only. Larger randomized studies are needed to confirm these findings.

Serum oxalate concentration is associated with coronary artery calcification and cardiovascular events in Japanese dialysis patients

Coronary artery calcification (CAC) is associated with cardiovascular disease (CVD). CAC might contain calcium oxalate, and a high serum oxalate (SOx) concentration is associated with cardiovascular mortality in dialysis patients. We assessed the associations between SOx and CAC or CVD events in Japanese hemodialysis patients. This cross-sectional and retrospective cohort study was done in 2011. Seventy-seven hemodialysis patients' Agatston CAC score was measured, and serum samples were collected. SOx concentrations were measured in 2021 by using frozen samples. Also, new-onset CVD events in 2011-2021 were retrospectively recorded. The association between SOx concentration and CAC score ≥ 1000, and new-onset CVD events were examined. Median SOx concentration and CAC score were 266.9 (229.5-318.5) µmol/L and 912.5 (123.7-2944), respectively. CAC score ≥ 1000 was associated with SOx [adjusted odds ratio (OR) 1.01, 95% confidence interval (CI), 1.00-1.02]. The number of new-onset CVD events was significantly higher in patients with SOx ≥ median value [hazard ratio (HR) 2.71, 95% CI 1.26-6.16]. By Cox proportional hazard models, new-onset CVD events was associated with SOx ≥ median value (adjusted HR 2.10, 95% CI 0.90-4.91). SOx was associated with CAC score ≥ 1000 and new-onset CVD events in Japanese hemodialysis patients.

The risk factors and predictive model for cardiac valve calcification in patients on maintenance peritoneal dialysis: a single-center retrospective study

BACKGROUND

Cardiovascular calcification includes cardiac valve calcification (CVC) and vascular calcification. We aimed to analyze risk factors for CVC, and construct a predictive model in maintenance peritoneal dialysis (MPD) patients.

METHODS

We retrospectively analyzed MPD patients who began peritoneal dialysis between January 2014 and September 2021. Patients were randomly assigned to the derivation cohort and validation cohort in a 7:3 ratio. The patients in the derivation cohort were divided into the CVC group and non-CVC group. Logistic regression was used to analyze risk factors, then the rms package in R language was used to construct a nomogram model to predict CVC.

RESULTS

1,035 MPD patients were included, with the age of 50.0 ± 14.2 years and 632 males (61.1%). Their median follow-up time was 25 (12, 46) months. The new-onset CVC occurred in 128 patients (12.4%). In the derivation cohort, multivariate logistic regression indicated old age, female, high systolic blood pressure (SBP), high calcium-phosphorus product (Ca × P), high Charlson comorbidity index (CCI) and long dialysis time were independent risk factors for CVC (p < 0.05). We constructed a nomogram model for predicting CVC in the derivation cohort, with a C index of 0.845 (95% CI 0.803-0.886). This model was validated with a C index of 0.845 (95%CI 0.781-0.909) in the validation cohort.

CONCLUSION

We constructed a nomogram model for CVC in MPD patients, using independent risk factors including age, sex, SBP, Ca × P, CCI and dialysis time. This model achieved high efficiency in CVC prediction.

Bile Acid Network and Vascular Calcification-Associated Diseases: Unraveling the Intricate Connections and Therapeutic Potential

Bile acids play a crucial role in promoting intestinal nutrient absorption and biliary cholesterol excretion, thereby protecting the liver from cholesterol accumulation and bile acid toxicity. Additionally, bile acids can bind to specific nuclear and membrane receptors to regulate energy expenditure and specific functions of particular tissues. Vascular calcification refers to the pathological process of calcium-phosphate deposition in blood vessel walls, which serves as an independent predictor for cardiovascular adverse events. In addition to aging, this pathological change is associated with aging-related diseases such as atherosclerosis, hypertension, chronic kidney disease, diabetes mellitus, and osteoporosis. Emerging evidence suggests a close association between the bile acid network and these aforementioned vascular calcification-associated conditions. Several bile acids have been proven to participate in calcium-phosphate metabolism, affecting the transdifferentiation of vascular smooth muscle cells and thus influencing vascular calcification. Targeting the bile acid network shows potential for ameliorating these diseases and their concomitant vascular calcification by regulating pathways such as energy metabolism, inflammatory response, oxidative stress, and cell differentiation. Here, we present a summary of the metabolism and functions of the bile acid network and aim to provide insights into the current research on the profound connections between the bile acid network and these vascular calcification-associated diseases, as well as the therapeutic potential.

[Association between sarcopenia and abdominal aortic calcification in maintenance hemodialysis patients]

Objective: To investigate the relationship between sarcopenia and abdominal aortic calcification (AAC) in maintenance hemodialysis (MHD) patients. Methods: A cross-sectional study was conducted. MHD patients who underwent regular dialysis between January 2021 and January 2022 at hemodialysis center in Jiangdu People's Hospital Affiliated to Yangzhou University were enrolled. The incidence of sarcopenia in these patients was examined by measuring handgrip strength, gait speed and appendicular skeletal muscle mass index (ASMI) using bioelectrical impedance analysis. AAC score was measured by a lateral lumbar spinal radiograph. The general information of the patients was collected and the blood biochemical indexes were detected. These patients were divided into non-calcification group (n=104) and calcification group (n=127) according to the score of AAC. Multivariate logistic regression was used to analyze the related factors of AAC. Results: A total of 231 MHD patients (134 males and 97 females) were enrolled in the study, with the mean age of (57.1±11.4) years. Among 231 hemodialysis patients, the incidence of sarcopenia and AAC were 46.3% (107 cases) and 55.0% (127 cases), respectively. The age [(60.2±11.1) vs (53.4±12.2) years, P<0.001] and dialysis vintage [86 (46, 135) vs 57 (27, 109) months, P=0.005] in calcification group were longer than these in the non-calcification group. The level of 25(OH)D3 [17.7 (13.5, 24.3) vs 20.5 (15.1, 28.1) μg/L, P=0.008] and gait speed [(0.88±0.23) vs (1.01±0.20) m/s, P=0.024], handgrip strength [(17.9±9.1) vs (20.7±9.9) kg, P=0.013], ASMI [(6.65±2.24) vs (7.83±2.46) kg/m2, P<0.001] were lower. While, AAC score [12 (9, 19) vs 0 (0, 3), P<0.001] and the incidence of sarcopenia [58.3% (74/127) vs 31.7% (33/104), P<0.001] were higher in the calcification group than these in the non-calcification group. Multivariate logistic regression analysis indicated that sarcopenia (OR=1.928, 95%CI: 1.302-2.855, P=0.001), decrease of 25(OH)D3 level (OR=0.969, 95%CI: 0.940-1.000, P=0.047), age (OR=1.043, 95%CI: 1.015-1.072, P=0.002), and dialysis vintage (OR=1.009, 95%CI: 1.004-1.015, P=0.001) were related factors of AAC. Conclusions: Sarcopenia is associated with AAC in MHD patients. In clinical practice, attention should be paid to sarcopenia in MHD patients.

Lactobacillus rhamnosus GG aggravates vascular calcification in chronic kidney disease: A potential role for extracellular vesicles

AIMS

Lactobacillus rhamnosus GG (LGG) is a probiotic with great promise in future clinical application, which can significantly promote bone formation. However, the effect of LGG on CKD-related vascular calcification is unclear. In this study, we aimed to investigate the effect of LGG on CKD-related vascular calcification.

MATERIALS AND METHODS

After 2 weeks of 5/6 nephrectomy, CKD rats received a special diet (4 % calcium and 1.8 % phosphate) combined with 1,25-dihydroxyvitamin D3 to induce vascular calcification. Meanwhile, CKD rats in the LGG group were gavaged orally with LGG (1 × 109 CFU bacteria/day). 16S RNA amplicon sequencing was performed to analyze the effect of LGG treatment on gut microbiota composition. Furthermore, differential ultracentrifugation was utilized to extract EVs. The effects of EVs on vascular calcification were evaluated in rat VSMCs, rat aortic rings, and CKD rat calcification models. In this study, vascular calcification was assessed by microcomputed tomography analysis, alizarin red staining, calcium content determination, and the expression of osteogenic transcription factors RUNX2 and BMP2.

KEY FINDINGS

LGG remarkably aggravated vascular calcification. LGG supplementation significantly altered gut microbiota composition in CKD rats, particularly increasing Lactobacillus. Interestingly, EVs presented a significant promoting effect on the development of calcification. Finally, mechanistic analysis proved that EVs aggravated vascular calcification through PI3K/AKT signaling.

SIGNIFICANCE

These results do not support the supplementation of LGG in CKD-associated vascular calcification patients. Our study presented a fresh perspective on LGG with potential risks and adverse effects. CKD patients should use specific probiotic strains cautiously.

Early diagnosis strategy of calciphylaxis in dialysis patients

Calciphylaxis, a rapidly progressive and potentially life-threatening vascular calcification syndrome that clinically presents with persistently painful, ulcerative, or necrotizing skin lesions in multiple parts of the body, is predominantly observed in patients treated with dialysis. Early diagnosis of calciphylaxis is a key measure for reducing high disability and mortality. At present, there is no unified diagnostic standard for calciphylaxis, and there is a lack of effective early screening strategies. This paper summarized and discussed the diagnostic accuracy of calciphylaxis based on the latest research worldwide. We propose a modified strategy for the early diagnosis of calciphylaxis, which is suitable for dialysis patients to help clinicians better identify such disease and improve prognosis.

Effect of low-calcium and standard-calcium dialysate on serum calcium, phosphorus and full-segment parathyroid hormone in patients on peritoneal dialysis: A retrospective observational study

OBJECTIVE

To investigate the effects of low-calcium and standard-calcium dialysate in patients with chronic kidney disease on peritoneal dialysis, and find out which dialysate has less vascular calcification effect.

METHODS

A total of 141 patients who had undergone peritoneal dialysis (PD) for 2 years in the PD centre from January 2012 to December 2017 were included and divided into two groups according to the calcium concentration of the PD fluid used. There were 79 cases in the low-calcium group, with a dialysate calcium concentration of 1.25 mmol/L and 62 cases in the standard-calcium group, with a dialysate calcium concentration of 1.75 mmol/L. The demographic characteristics and clinical information before initiation of PD were collected and compared between the two groups. Information on the serum calcium, phosphorus and PTH, systolic and diastolic blood pressures and the use of antihypertensive and phosphate-lowering drugs in the second year of dialysis was also collected and compared between the two groups. Vascular calcification was assessed in patients on PD treatment.

RESULTS

The mean serum calcium concentrations before initiation of PD in the low- and standard-calcium groups were 1.94 ± 0.27 and 1.89 ± 0.28 mmol/L, respectively. The serum calcium concentrations after PD were 2.30 ± 0.21 and 2.41 ± 0.23 mmol/L, respectively. After PD, the serum calcium concentration in both groups was significantly increased (p < 0.05). The serum calcium concentration in the low-calcium group after PD treatment was lower than that in the standard-calcium group, and the difference was statistically significant (p < 0.05). Compared with the standard-calcium group, patients in the low-calcium group had significantly higher parathyroid hormone concentrations (p < 0.05). More types of phosphate-lowering drugs were used (59.49%) in the low-calcium group than that in the standard-calcium group (35.48%; p < 0.05). The number of antihypertensive drug usage were also higher in the low-calcium group, and the difference was statistically significant (p < 0.05). As for the vascular calcification effect, the two groups have shown no statistical difference in abdominal aortic calcification rate, carotid arteriosclerosis rate and aortic arch calcification rate (p < 0.05).

CONCLUSION

We found that low-calcium PD fluid may increase the PTH level and the proportion of CKD patients using antihypertensive drug and phosphorus-lowering drug, but the vascular calcification effect of the low and standard calcium PD fluid needs further exploration. This paper provides new evidence for the choice of dialysate for PD, low-calcium dialysate has no outstanding advantages for long term dialysis.

Early experience of intravascular lithotripsy in unprotected calcified left main coronary artery disease

BACKGROUND

Treatment of unprotected severely calcified left main coronary artery (LMCA) disease is a complex interventional procedure. Intravascular lithotripsy (IVL) and rotational atherectomy (RA) are safe and effective methods of treating coronary calcification in the non-LMCA setting. This retrospective analysis assessed the feasibility of IVL versus RA in unprotected LMCA disease.

METHODS

We analyzed IVL and RA procedures performed at a large tertiary hospital in the Northeast of England from January 1, 2019 to April 31, 2022. Major safety and efficacy endpoints were procedural and angiographic success, defined by stent delivery with <50 % residual stenosis and without clinical or angiographic complications, respectively. Another important clinical endpoint was the composite of major adverse cardiac events (MACE) at 1 year.

RESULTS

From 242 patients, 44 had LMCA IVL, 81 had LMCA RA and 117 had non-LMCA IVL. Patients with LMCA disease were older and more likely to have aortic stenosis. IVL was a second-line or bailout technique in 86.4 % LMCA and 92.2 % non-LMCA cases. Procedural and angiographic success rates were ≥ 84 % across all groups (p > 0.05). In 3 LMCA IVL and 3 LMCA RA cases arrhythmias and cardiac tamponade complicated the procedures respectively. At 1 year, MACE occurred in 10/44 (22.7 %) LMCA IVL, 16/81 (19.8 %) LMCA RA and 25/117 (21.4 %) cases (p > 0.05).

CONCLUSION

In our single center retrospective analysis, IVL is feasible in unprotected calcified LMCA as a second-line and third-line adjuvant calcium modification technique. Its use in unprotected calcified LMCA disease should be formalized with the undertaking of large randomized controlled trials.

The WNT/β-catenin system in chronic kidney disease-mineral bone disorder syndrome

BACKGROUND

The WNT/β-catenin system is an evolutionarily conserved signaling pathway that plays a crucial role in morphogenesis and cell tissue formation during embryogenesis. Although usually suppressed in adulthood, it can be reactivated during organ damage and regeneration. Transient activation of the WNT/β-catenin pathway stimulates tissue regeneration after acute kidney injury, while persistent (uncontrolled) activation can promote the development of chronic kidney disease (CKD). CKD-MBD is a clinical syndrome that develops with systemic mineral and bone metabolism disorders caused by CKD, characterized by abnormal bone mineral metabolism and/or extraosseous calcification, as well as cardiovascular disease associated with CKD, including vascular stiffness and calcification.

OBJECTIVE

This paper aims to comprehensively review the WNT/β-catenin signaling pathway in relation to CKD-MBD, focusing on its components, regulatory molecules, and regulatory mechanisms. Additionally, this review highlights the challenges and opportunities for using small molecular compounds to target the WNT/β-catenin signaling pathway in CKD-MBD therapy.

METHODS

We conducted a comprehensive literature review using various scientific databases, including PubMed, Scopus, and Web of Science, to identify relevant articles. We searched for articles that discussed the WNT/β-catenin signaling pathway, CKD-MBD, and their relationship. We also reviewed articles that discussed the components of the WNT/β-catenin signaling pathway, its regulatory molecules, and regulatory mechanisms.

RESULTS

The WNT/β-catenin signaling pathway plays a crucial role in CKD-MBD by promoting vascular calcification and bone mineral metabolism disorders. The pathway's components include WNT ligands, Frizzled receptors, and LRP5/6 co-receptors, which initiate downstream signaling cascades leading to the activation of β-catenin. Several regulatory molecules, including GSK-3β, APC, and Axin, modulate β-catenin activation. The WNT/β-catenin signaling pathway also interacts with other signaling pathways, such as the BMP pathway, to regulate CKD-MBD.

CONCLUSIONS

The WNT/β-catenin signaling pathway is a potential therapeutic target for CKD-MBD. Small molecular compounds that target the components or regulatory molecules of the pathway may provide a promising approach to treat CKD-MBD. However, more research is needed to identify safe and effective compounds and to determine the optimal dosages and treatment regimens.

Intra-Cranial Arterial Calcifications in Hemodialysis Patients

Background and objectives: Vascular calcification is an integral part of atherosclerosis and has been reported to be an independent risk factor for cardiovascular diSsease. Intra Cranial Arterial Calcifications (ICAC) in maintenance hemodialysis (MHD) is highly prevalent. Materials and Methods: The aim of this retrospective study was to assess the predictors and outcomes of ICAC in MHD patients compared to a control group without kidney disease. A blinded neuroradiologist graded ICAC in brain imaging (computerized tomography) of MHD patients. Age- and sex-matched patients with normal kidney function served as the control group. Results: A total of 280 patients were included in the cohort; 140 of them were MHD patients with a mean ICAC score of 2.3 ± 0.2 versus a mean ICAC score of 1.4 ± 0.2 in the control group (p < 0.01). More than 90% of hemodialysis patients in our study had some degree of ICAC. Lower albumin and higher phosphorus and CRP levels were associated with increased ICACs. The multivariate analysis model for predictors of 1-year mortality demonstrated an increased odds ratio for mortality as the ICAC score increased. Conclusions: ICAC is very prevalent among MHD patients and results not simply from passive deposition of calcium and phosphate but rather from complex and active processes involving inflammation and structural changes in blood vessels. ICAC independently predicted all-cause mortality and may help with risk stratification of this high-risk population.