Aortic arch calcification predicts cardiovascular and all-cause mortality in maintenance hemodialysis patients

Associations of essential metals with the risk of aortic arch calcification: a cross-sectional study in a mid-aged and older population of Shenzhen, China

Vascular calcification is a strong predictor of cardiovascular events. Essential metals play critical roles in maintaining human health. However, the association of essential metal levels with risk of aortic arch calcification (AoAC) remains unclear. We measured the plasma concentrations of nine essential metals in a cross-sectional population and evaluated their individual and combined effects on AoAC risk using multiple statistical methods. We also explored the mediating role of fasting glucose. In the logistic regression model, higher quartiles of magnesium and copper were associated with the decreased AoAC risk, while higher quartile of manganese was associated with higher AoAC risk. The least absolute shrinkage and selection operator penalized regression analysis identified magnesium, manganese, calcium, cobalt, and copper as key metals associated with AoAC risk. The weighted quantile sum regression suggested a combined effect of metal mixture. A linear and positive dose-response relationship was found between manganese and AoAC in males. Moreover, blood glucose might mediate a proportion of 9.38% of the association between manganese exposure and AoAC risk. In summary, five essential metal levels were associated with AoAC and showed combined effect. Fasting glucose might play a significant role in mediating manganese exposure-associated AoAC risk.

Citric acid-based bicarbonate dialysate attenuates aortic arch calcification in maintenance hemodialysis patients: a retrospective observational study

BACKGROUND

Progression of aortic calcification is associated with all-cause and cardiovascular mortality in hemodialysis patients. Blood calciprotein particle (CPP) levels are associated with coronary artery calcification and were reported to be inhibited when using citric acid-based bicarbonate dialysate (CD). Therefore, this study aimed to examine the effect of CD on the progression of the aortic arch calcification score (AoACS) and blood CPP levels in hemodialysis patients.

METHODS

A 12-month retrospective observational study of 262 hemodialysis patients was conducted. AoACS was evaluated by calculating the number of calcifications in 16 segments of the aortic arch on chest X-ray (minimum score is 0; maximum score is 16 points). The patients were divided into the following groups according to their baseline AoACS: grade 0, AoACS = 0 points; grade 1, AoACS 1-4 points; grade 2, AoACS 5-8 points; grade 3, AoACS 9 points or higher. Patients on bisphosphonates or warfarin or with AoACS grade 3 were excluded. Progression, defined as ΔAoACS (12-month score - baseline score) > 0 points, was compared between the CD and acetic acid-based bicarbonate dialysate (AD) groups before and after adjusting the background using propensity score matching.

RESULTS

The AoACS progression rate was significantly lower in the CD group than in the AD group (before matching: P = 0.020, after matching: P = 0.002). Multivariate logistic regression analysis showed that CD was significantly associated with AoACS progression (odds ratio 0.52, 95% confidence interval 0.29‒0.92, P = 0.025).

CONCLUSION

CD may slow the progression of vascular calcification in hemodialysis patients.

Impact of Arterial Calcification of the Lower Limbs on Long-Term Clinical Outcomes in Patients on Hemodialysis

Lower limbs' arterial calcification is significantly associated with the clinical severity of lower extremity artery disease (LEAD) in patients undergoing hemodialysis (HD). However, the association between arterial calcification of the lower limbs and long-term clinical outcomes in patients on HD has not been elucidated. Calcification scores of the superficial femoral artery (SFACS) and below-knee arteries (BKACS) were quantitatively evaluated in 97 HD patients who were followed for 10 years. Clinical outcomes, including all-cause and cardiovascular mortality, cardiovascular events, and limb amputation were evaluated. Risk factors for clinical outcomes were evaluated using univariate and multivariate Cox proportional hazard analyses. Furthermore, SFACS and BKACS were divided into three groups (low, middle, and high), and their associations with clinical outcomes were evaluated using Kaplan-Meier analysis. SFACS, BKACS, C-reactive protein, serum albumin, age, diabetes, presence of ischemic heart disease, and critical limb-threatening ischemia were significantly associated with 3-year and 10-year clinical outcomes in the univariate analysis. Multivariate analysis showed that SFACS was an independent factor associated with 10-year cardiovascular events and limb amputations. Kaplan-Meier life table analysis showed that higher SFACS and BKACS levels were significantly associated with cardiovascular events and mortality. In conclusion, long-term clinical outcomes and the risk factors in patients undergoing HD were evaluated. Arterial calcification of the lower limbs was strongly associated with 10-year cardiovascular events and mortality in patients undergoing HD.

Association of aortic arch and aortic valve calcifications with cardiovascular risk in patients on maintenance hemodialysis

Introduction

This study aimed to investigate the association of aortic arch calcification (AoAC) and aortic valve calcification (AVC) with major adverse cardiovascular events (MACE) and cardiovascular and all-cause mortality in patients on maintenance hemodialysis (MHD).

Methods

This study enrolled 297 adult patients with end-stage kidney disease who were on MHD. They were divided into those with an AoAC score <2 without AVC (n = 70, 23.6%), those with an AoAC score <2 with AVC (n = 96, 32.3%), and those with an AoAC score ≥2 regardless of AVC status (n = 131, 44.1%). We analyzed the risks of MACE, cardiovascular and overall mortality among the three groups using Cox proportional hazard analyses. Survival probabilities were estimated using the log-rank test via the Kaplan-Meier method.

Results

Kaplan-Meier analysis revealed that the MACE-free rate and the survival rates of cardiovascular and overall mortality were significantly higher in adult chronic hemodialysis patients with AoAC score <2 without AVC, followed by those with AoAC score <2 with AVC, and then those with AoAC score ≥2 (log-rank test; all p < 0.01). The grade of AoAC is a significant risk factor for MACE, cardiovascular mortality, and overall mortality after adjusting for age and gender Relative to AoAC score <2 without AVC, adult chronic hemodialysis patients with AoAC score ≥2 remained an independently significantly risk factor of MACE (adjusted hazard ratio, 2.17; 95% confidence interval 1.11-4.20; p = 0.023) after adjusting for age, sex, and all significant variables in baseline characteristics.

Conclusion

AoAC grade was positively correlated with a higher risk of MACE and cardiovascular and overall mortality. Furthermore, the presence of AVC modified the adverse cardiovascular risk associated with AoAC in patients on MHD.

Aortic arch calcification and risk of all-cause mortality and cardiovascular disease: The Guangzhou Biobank Cohort Study

Background

There were no reports on the associations of aortic arch calcification (AAC) measured by chest X-ray with all-cause mortality and cardiovascular disease (CVD) in older general population. Moreover, previous studies of hemodialysis patients showed that AAC was correlated with left ventricular hypertrophy (LVH) and predicted CVD jointly. Whether the effects remained in the general population is unknown. We examined the associations of AAC with all-cause mortality and CVD in general population and the risk associated with the coexistence of AAC and LVH.

Methods

Presence and severity (grades 0-2) of AAC were measured by chest X-ray, and LVH was identified by 12-lead electrocardiogram in 27,166 Chinese aged 50+ years free of CVD from Guangzhou Biobank Cohort Study. Multivariate Cox regressions were used to examine associations of AAC and LVH with outcomes.

Findings

During an average follow-up of 14·3 years, 5,350 deaths and 4,012 CVD occurred. Compared to those without AAC at baseline, those with AAC had higher risks of all-cause mortality (HR 1·24, 95% CI 1·17-1·31) and CVD (HR 1·22, 95% CI 1·14-1·30), with dose-response relationship (P ≤ 0·001). Furthermore, those with coexistence of AAC and LVH had higher risks of all-cause mortality (HR 1·72, 95% CI 1·37-2·15) and CVD (HR 1·80, 95% CI 1·40-2·32) than those without AAC and LVH.

Interpretation

As chest X-ray has been performed commonly for health screening and in hospital patients when first admitted, AAC measured by chest X-ray can be further applied to assist cardiovascular risk stratification in the community and clinical settings.

Funding

The Natural Science Foundation of China (No. 81941019).

Aortic arch calcification affects causes of death in patients on hemodialysis: a retrospective cohort study

Background

Aortic arch calcification (AAC) is a well-known risk factor for death in patients on hemodialysis (HD); however, the causes of death among them have not been well studied. The study aimed to investigate the distribution of causes of death and long-term prognosis among different degrees of AAC in HD patients.

Methods

A retrospective cohort study was conducted on patients undergoing HD at two clinics in Japan. AAC grades 0 to 3 were categorized by chest radiograph at baseline, and mortality and causes of death were collected. A subgroup analysis was performed to evaluate the relationship between causes of death and age, diabetes mellitus, and dialysis vintage in each AAC grade.

Results

A total of 321 patients were included in the analysis. During 5.2 ± 2.1 years, 117 patients died, and the death rates in AAC grades 0, 1, 2, and 3 were 19.3% (17/88), 35.2% (51/145), 46.3% (25/54), and 70.6% (24/34), respectively. The major causes of death were cardiovascular disease (CVD, 39.3%), infection (20.5%), and malignancy (15.4%) in the entire cohort. In AAC grade 3, CVD mortality (33.3%) remains as the most common cause of death, although death of infection (29.2%) and malnutrition (16.7%) increased markedly. A subgroup analysis showed that AAC grade 3 was mostly old, non-diabetic patients with a long dialysis vintage and was susceptible to death of infection or malnutrition.

Conclusions

CVD was the most common cause of death among all AAC grades, although death of infection and malnutrition markedly increased in those with severe AAC. Attention should be paid to CVD, infection, and malnutrition in HD patients with severe AAC.

Circulating miRNA-29b and Sclerostin Levels Correlate with Coronary Artery Calcification and Cardiovascular Events in Maintenance Hemodialysis Patients

Objective

Coronary artery calcification (CAC) is a common complication in end-stage renal disease (ESRD) patients undergoing maintenance hemodialysis (MHD), and the extent of CAC is a predominant predictor of cardiovascular outcomes in MHD patients. In this study, we sought to uncover the relationship between circulating miRNA-29b, sclerostin levels, CAC, and cardiovascular events (CVEs) in MHD patients.

Methods

This study recruited patients receiving MHD for at least three months in the Hainan General Hospital between January 2016 and June 2019, and all patients were followed up 24 months for CVEs. The serum level of sclerostin was determined by enzyme-linked immunosorbent assay (ELISA) and miRNA-29b expression by real-time qPCR (RT-qPCR). All patients received cardiac CT scans to evaluate CAC, and CAC scores were expressed in Agatston units. The MHD patients with CACs <100 were arranged into the CAC (<100) group, those with 100–400 CACs into the CAC (100–400) group, and those with CACs >400 into the CAC (>400) group. Net reclassification index (NRI) and integrated discrimination index (IDI) were calculated to assess the predictive performance of serum sclerostin level for the occurrence of CVEs.

Results

Compared with the CAC (<100) group, the CAC (>400) group had higher proportions of older patients, hypertension and diabetes mellitus patients, longer dialysis duration, higher mean arterial pressure (MAP), higher levels of high-sensitivity C-reactive protein (hs-CRP), alkaline phosphatase (ALP), and phosphate (P < 0.05). It was found that the CAC (100–400) and CAC (>400) groups exhibited higher serum levels of sclerostin but lower levels of miRNA-29b than the CAC (<100) group (P < 0.05) and the CAC (>400) group had a higher level of sclerostin and a lower level of miRNA-29b than the CAC (100–400) group (P < 0.05). The circulating level of miRNA-29b was negatively correlated with the serum level of sclerostin in MHD patients (r = −0.329, P < 0.01). The multivariate logistic regression analysis showed that hs-CRP, phosphate, sclerostin, and miRNA-29b were independent risk factors for CAC in MHD patients (P < 0.05, Table 2). ROC for prediction of CAC by sclerostin yielded 0.773 AUC with 95% CI 0.683–0.864 (P < 0.01). As depicted by Kaplan–Meier curves of CVE incidence in MHD patients according to median sclerostin (491.88 pg/mL) and median miRNA-29b (Ct = 25.15), we found that serum levels of sclerostin and miRNA-29b were correlated with the incidence of CVEs in MHD patients. When a new model was used to predict the incidence of CVEs, NRI 95% CI was 0.60 (0.16–1.03) (P < 0.05) and IDI 95% CI was 0.002 (−0.014 to 0.025) (P < 0.05), suggesting that sclerostin added into the old model could improve the prediction of the incidence of CVEs.

Conclusions

These data suggest that circulating miRNA-29b and sclerostin levels are correlated with CAC and incidence of CVEs in MHD patients. Higher sclerostin and lower miRNA-29b may serve as independent risk factors for the incidence of CVEs in MHD patients.

Impact of serum albumin level and variability on short-term cardiovascular-related and all-cause mortality in patients on maintenance hemodialysis

Studies have shown that low serum albumin (Salb) levels are associated with a high risk of mortality among patients on maintenance hemodialysis (MHD); however, the impact of Salb variability on short-term cardiovascular mortality remains unclear. Herein, we investigated the association between Salb levels and Salb variability on short-term all-cause and cardiovascular-related mortality in patients on MHD.Eligible patients on MHD at Chongqing General Hospital between June 2017 and June 2020 were recruited in this study. Patients were grouped by Salb levels (normal Salb, ≥3.8 g/dL; low Salb, 3.4-3.8 g/dL; and lower Salb, 2-3.4 g/dL) and Salb variability (decreased, >5% loss; increased, >5% gain; and steady, 5% loss to 5% gain). Associations between Salb levels, Salb variability, and all-cause and cardiovascular-related mortality were analyzed using Cox regression models. A survival analysis was performed using the Kaplan-Meier analysis.We enrolled a total of 181 patients on MHD with an average age of 65 years (interquartile range [IQR], 53-75 years). The mean Salb level was 3.8 ± 0.6 g/dL (IQR 2.9-4.4 g/dL), and the median Salb variability was 2.6% per year (IQR, -4.1 to 6.5). Fifty-two (29%) patients died, including 31 (17%) patients who died due to cardiovascular-related causes. Compared with the other groups, the lower Salb group had higher all-cause mortality (P < .01). Cox regression analyses revealed that lower Salb levels and decreased Salb variability were independently associated with all-cause mortality (hazard ratio [HR] = 1.95, 95% confidence interval [CI] 1.103-3.452; HR = 2.245, 95% CI 1.084-4.650), whereas increased Salb variability was independently associated with cardiovascular-related mortality (HR = 2.919, 95% CI 1.178-7.234; P < .05).Lower Salb levels were an independent predictor of all-cause mortality in patients on MHD. Increased Salb variability was strongly associated with cardiovascular-related mortality in the same population, especially in the short-term and in patients with normal Salb levels. Significantly elevated Salb variability should be evaluated to reduce cardiovascular-related mortality.

Prognostic Implication of Longitudinal Changes in Cardiothoracic Ratio and Aortic Arch Calcification in Hemodialysis Patients

Patients with end-stage renal disease have a high prevalence of cardiovascular disease. Chest radiography can be used to assess cardiothoracic ratio (CTR) and aortic arch calcification (AoAC). The aims of this longitudinal follow-up study were to investigate factors associated with changes in CTR and AoAC and understand whether these changes are associated with overall and cardiovascular mortality in hemodialysis (HD) patients. We enrolled 260 patients undergoing HD who had at least two available chest X-rays from 2008 to 2015. CTR and AoAC were assessed in each patient using measurements from baseline and annual chest X-rays. The CTR increased from 49.05% to 51.86% and the AoAC score increased from 3.84 to 9.73 over 7 years. The estimated slopes were 0.24 (p < 0.0001) for CTR and 0.08 (p = 0.0441) for AoAC. Increased AoAC, older age, female sex, coronary artery disease, and decreased albumin were associated with an increase in CTR, and older age, cerebrovascular disease, decreased albumin, increased Kt/V, and the use of antiplatelet agents were associated with an increase in AoAC. During follow-up, 136 of the 260 (52.3%) patients died, of whom 72 died due to cardiovascular causes. The change in CTR was greater in those who died (p = 0.0125) than in those who survived. The AoAC score was also higher in those who died than in those who survived, although there was no significant difference in the change in AoAC between the two groups (p = 0.8035). CTR and AoAC increased significantly over time in the HD patients in this longitudinal follow-up study, and the change in CTR was greater in those who died than in those who survived. Chest radiography is a simple and useful tool to assess the progression of CTR and AoAC as a prognostic marker.

Gender-Related Differences in Chronic Kidney Disease-Associated Vascular Calcification Risk and Potential Risk Mediators: A Scoping Review

Vascular calcification (VC) involves the deposition of calcium apatite in vascular intima or media. Individuals of advanced age, having diabetes mellitus or chronic kidney disease (CKD) are particularly at risk. The pathogenesis of CKD-associated VC evolves considerably. The core driver is the phenotypic change involving vascular wall constituent cells toward manifestations similar to that undergone by osteoblasts. Gender-related differences are observed regarding the expressions of osteogenesis-regulating effectors, and presumably the prevalence/risk of CKD-associated VC exhibits gender-related differences as well. Despite the wealth of data focusing on gender-related differences in the risk of atherosclerosis, few report whether gender modifies the risk of VC, especially CKD-associated cases. We systematically identified studies of CKD-associated VC or its regulators/modifiers reporting data about gender distributions, and extracted results from 167 articles. A significantly higher risk of CKD-associated VC was observed in males among the majority of original investigations. However, substantial heterogeneity exists, since multiple large-scale studies yielded neutral findings. Differences in gender-related VC risk may result from variations in VC assessment methods, the anatomical segments of interest, study sample size, and even the ethnic origins of participants. From a biological perspective, plausible mediators of gender-related VC differences include body composition discrepancies, alterations involving lipid profiles, inflammatory severity, diversities in matrix Gla protein (MGP), soluble Klotho, vitamin D, sclerostin, parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23), and osteoprotegerin levels. Based on our findings, it may be inappropriate to monotonously assume that male patients with CKD are at risk of VC compared to females, and we should consider more background in context before result interpretation.

Aortic Arch Calcification and Cardiomegaly Are Associated with Overall and Cardiovascular Mortality in Hemodialysis Patients

Patients with end-stage renal disease have a higher risk of cardiovascular morbidity and mortality. In this study, we investigated the predictive ability of a combination of cardiothoracic ratio (CTR) and aortic arch calcification (AoAC) for overall and cardiovascular mortality in patients receiving hemodialysis. We also evaluated the predictive power of AoAC and CTR for clinical outcomes. A total of 365 maintenance hemodialysis patients were included, and AoAC and CTR were measured using chest radiography at enrollment. We stratified the patients into four groups according to a median AoAC score of three and CTR of 50%. Multivariable Cox proportional hazards analysis was used to identify the risk factors of mortality. The predictive performance of the model for clinical outcomes was assessed using the χ2 test. Multivariable analysis showed that, compared to the AoAC < 3 and CTR < 50% group, the AoAC ≥ 3 and CTR < 50% group (hazard ratio [HR], 4.576; p < 0.001), and AoAC ≥ 3 and CTR ≥ 50% group (HR, 5.912; p < 0.001) were significantly associated with increased overall mortality. In addition, the AoAC < 3 and CTR ≥ 50% (HR, 3.806; p = 0.017), AoAC ≥ 3 and CTR < 50% (HR, 4.993; p = 0.002), and AoAC ≥ 3 and CTR ≥ 50% (HR, 8.614; p < 0.001) groups were significantly associated with increased cardiovascular mortality. Furthermore, adding AoAC and CTR to the basic model improved the predictive ability for overall and cardiovascular mortality. The patients who had a high AoAC score and cardiomegaly had the highest overall and cardiovascular mortality among the four groups. Furthermore, adding AoAC and CTR improved the predictive ability for overall and cardiovascular mortality in the hemodialysis patients.

Association of sclerostin with cardiovascular events and mortality in dialysis patients

Introduction

Sclerostin has been reported to be a novel biomarker associated with the bone-vascular axis. In this study, we determined the relationships between serum sclerostin and all-cause mortality, the prevalence of cardiovascular events (CVEs), and coronary artery calcifications (CACs) in dialysis patients.

Methods

A total of 165 dialysis patients (84 hemodialysis [HD] and 81 peritoneal dialysis [PD]) were enrolled in this study. We performed multivariable linear regression analysis to test the relationships between serum sclerostin levels and demographics and clinical parameters. We also performed Cox proportional hazard regression analysis to determine independent predictors of overall survival and CVEs.

Results

The median serum sclerostin level was 250.9 pg/mL in dialysis patients. Kaplan–Meier analysis showed that both overall and CVE-free survival rates were significantly lower in the high serum sclerostin group (serum sclerostin level >250.9 pg/mL) compared to the low serum sclerostin group (serum sclerostin level ≤250.9 pg/mL) in patients with PD (p < 0.05). In patients with HD, only CVE-free survival rates notably declined in the high serum sclerostin group compared to the low serum sclerostin group (p = 0.029). However, serum sclerostin level was only an independent predictor of all-cause mortality and CVEs in patients with PD after adjusting for confounding factors (p < 0.05), and therefore was not an independent predictor for patients with HD (p > 0.05).

Conclusions

A low serum sclerostin was associated with better overall survival and lower prevalence of CVEs in patients with PD, but had no relationships in patients with HD. We found that serum sclerostin level was not correlated with CACs in either patients with HD or PD.

Progression of Aortic Arch Calcification Is Associated with Overall and Cardiovascular Mortality in Hemodialysis

Background

Vascular calcification is common and associated with unfavorable outcomes among patients with end-stage renal disease (ESRD). Nevertheless, little is known whether the progression of vascular calcification outweighs the baseline calcification in association with overall and cardiovascular (CV) mortality in hemodialysis (HD) patients.

Methods

This study included 140 maintenance HD patients. Vascular calcification was assessed using the aortic arch calcification (AoAC) score measured from chest radiographs at the baseline and the second year of follow-up. Progression of vascular calcification (ΔAoAC) was defined as the difference between the two measurements of AoAC. The association of ΔAoAC with overall and CV mortality was evaluated using multivariate Cox regression analysis.

Results

During the mean follow-up period of 5.8 years, there were 49 (35%) overall mortality and 27 (19.3%) CV mortality. High brachial-ankle pulse wave velocity was positively correlated with ΔAoAC, whereas old age was negatively correlated with ΔAoAC. In multivariate adjusted Cox analysis, increased ΔAoAC (per 1 unit), but not baseline AoAC, was significantly associated with overall mortality (HR, 1.183; 95% CI, 1.056–1.327; p = 0.004) and CV mortality (HR, 1.194; 95% CI, 1.019–1.398; p = 0.028).

Conclusion

Progression of AoAC outperformed the baseline AoAC in association with increased risk of overall and CV mortality in HD patients. A regular follow-up of chest radiograph and AoAC score assessments are simple and cost-effective to identify the high-risk individuals of unfavorable outcomes in maintenance HD patients.

Association between acute aortic dissection and the distribution of aortic calcification

Objective

Aortic calcification (AC) is associated with increased risks of cardiovascular events and mortality. Numerous studies have explored the association between calcification and abdominal artery aneurysm. However, evidence regarding the association between AC and acute aortic dissection (AAD) is limited. We aimed to evaluate the association between AC-related variables and the development of intimal tear (IT) in patients with AAD.

Methods

We conducted a retrospective observational study involving 64 patients with type A AAD and 32 patients with type B AAD from February, 2011 to January, 2017 at a tertiary referral medical center in Taiwan. We used the default analysis module “calcification score analysis” to calculate all the calcification variables, including AC scores and volume.

Results

We identified an association between AC and AAD. Patients with AAD had a greater AC volume in the aortic arch and greater AC scores for both the ascending aorta and the aortic arch than did patients without AAD. However, hypertension and coronary artery disease, rather than AC remained to be the independent risk factor for AAD in multivariate analysis. Patients with type A AAD had greater mean and cumulative AC volumes in the aortic arch, greater cumulative AC volumes in the whole aorta and higher cumulative AC scores in the aortic arch than did patients with type B AAD. ACs were superimposed on ITs in nearly half of the patients with AAD. In patients with type A AAD, AC was more commonly located distal to the IT and farther from the IT.

Conclusions

We identified the associations between AC-related variables and the location of IT in patients with AAD. However, AC was not an independent risk factor for AAD. The distribution of AC was different between patients with type A and type B AAD.

Comparison of Solute Clearance, Hospitalization Rate, and Aortic Arch Calcification between Online Hemodiafiltration and High-Flux Hemodialysis: A 6-Year Observational Study

BACKGROUND/AIMS

Studies on the long-term clinical benefits of hemodiafiltration (HDF) and high-flux hemodialysis (HFHD) are very limited. This study aimed to investigate the hospitalization rate and aortic arch calcification (AAC) of these two dialysis modalities over 6 years.

METHODS

Participants who received regular HDF and HFHD in one hospital-facilitated hemodialysis center were prospectively enrolled after matching for age, sex, and diabetes between January 2009 and December 2014. Medical records were reviewed retrospectively on demographics, laboratory variables, calcified scores in aortic arch measured by chest radiography, and rates of hospital admission. Cox proportional hazard regression and linear regression were used to obtain the outcome results.

RESULTS

The HDF and HFHD groups consisted of 108 and 102 participants, respectively. Levels of laboratory variables including small soluble solutes and Kt/V were not statistically different over the 6-year period between the HDF and HFHD groups. Calcified scores of the aortic arch increased over 6 years in both groups. The changes in the mean calcified scores were significant when compared between the two groups (0.44-1.82 in HFHD, 0.79-1.8 in HDF, respectively, p = 0.008). Hospitalization rates were 735 per 1,000 patients in the HDF group and 852 per 1,000 patients in the HFHD group, respectively. No significant difference was observed in frequency and days of hospitalization between HDF and HFHD.

CONCLUSION

Hospitalization rates and AAC were observed to be equal for HDF and HFHD.

Increased Aortic Arch Calcification and Cardiomegaly is Associated with Rapid Renal Progression and Increased Cardiovascular Mortality in Chronic Kidney Disease

Vascular calcification and cardiomegaly are highly prevalent in chronic kidney disease (CKD) patients. However, the association of the combination of aortic arch calcification (AoAC) and cardio-thoracic ratio (CTR) with clinical outcomes in patients with CKD is not well investigated. This study investigated whether the combination of AoAC and CTR is associated with poor clinical outcomes in CKD stages 3–5 patients. We enrolled 568 CKD patients, and AoAC and CTR were determined by chest radiography at enrollment. Rapid renal progression was defined as estimated glomerular filtration rate (eGFR) decline over 3 ml/min/1.73 m² per year. Both AoAC score and CTR were significantly associated with rapid renal progression. High CTR was correlated with increased risk for cardiovascular mortality. We stratified the patients into four groups according to the median AoAC score of 4 and CTR of 50%. Those with AoAC ≥ 4 and CTR ≥ 50% (vs. AoAC score < 4 and CTR < 50%) were associated with eGFR decline over 3 ml/min/1.73 m²/year and cardiovascular mortality. AoAC and CTR were independently associated with eGFR slope. In conclusion, the combination of increased AoAC and cardiomegaly was associated with rapid renal progression and increased cardiovascular mortality in patients with CKD stage 3–5 patients. We suggest that evaluating AoAC and CTR on chest plain radiography may be a simple and inexpensive method for detecting CKD patients at high risk for adverse clinical outcomes.

Usefulness of pretransplant aortic arch calcification evaluation for kidney transplant outcome prediction in one year follow-up

Vascular calcification (VC) is linked to post-transplant cardiovascular events and hypercalcemia which may influence kidney graft function in the long term. We aimed to evaluate whether pretransplant aortic arch calcification (AoAC) can predict post-transplant cardiovascular or cerebrovascular events (CVEs), and to assess its association with post-transplant plasma calcium levels and renal function in one-year follow-up. Our single-center observational prospective study enrolled 37 kidney transplant recipients (KTR) without previous history of vascular events. Two radiologists evaluated pretransplant AoAC on chest X-ray as suggested by Ogawa et al. in 2009. Cohen’s kappa coefficient was 0.71. The mismatching results were repeatedly reviewed and resulted in consensus. Carotid-femoral (cfPWV) and carotid-radial pulse wave velocity (crPWV) was measured using applanation tonometry before and one year after transplantation. Patient clinical, biochemical data, and cardiovascular/CVE rate were monitored within 1 year. We found out that eGFR_1year correlated with eGFR_discharge and calcium based on hospital discharge data (β = 0.563, p = .004 and β = 51.360, p = .026, respectively). Multivariate linear regression revealed that donor age, donor gender, and recipient eGFR_discharge (R-squared 0.65, p = .002) better predict eGFR_1year than AoAC combined with recipient eGFR_discharge (R-squared 0.35, p = .006). During 1-year follow-up, four (10.81%) patients experienced cardiovascular events, which were predicted by PWV ratio (HR 7.549, p = .045), but not related to AoAC score (HR 1.044, p = .158). In conclusion, KTR without previous vascular events have quite low cardiovascular/CVE rate within 1-year follow-up. VC evaluated as AoAC on pretransplant chest X-ray together with recipient eGFR_discharge could be related to kidney function in one-year follow-up.

Vascular Calcification: Current Genetics Underlying This Complex Phenomenon

OBJECTIVE

Vascular calcification is the consequence of the complex interaction between genetic, environmental, and vascular factors, which ultimately lead to the deposition of calcium in the tunica intima (atherosclerotic calcification) or tunica media (Mönckenberg's sclerosis). Vascular calcification is also closely related to other pathologies, such as diabetes mellitus, dyslipidemia, and chronic kidney disease. It has been concluded that the degree of vascular calcification may vary from person to person, even if the associated pathologies and environmental factors are the same. Therefore, this suggests an important genetic contribution to the development of vascular calcification. This review aimed to find the most recent evidence about vascular calcification pathophysiology regarding the genetic aspects and molecular pathways.

DATA SOURCES

We conducted an exhaustive search in Scopus, EBSCO, and PubMed with the keywords "genetics and vascular calcification", "molecular pathways, genetic and vascular calcification" and included the main articles from January 1995 up to August 2016. We focused on the most recent evidence about vascular calcification pathophysiology regarding the genetic aspects and molecular pathways.

STUDY SELECTION

The most valuable published original and review articles related to our objective were selected.

RESULTS

Vascular calcification is a multifactorial disease; thus, its pathophysiology cannot be explained by a single specific factor, rather than by the result of the association of several genetic variants, molecular pathway interactions, and environmental factors that promote its development.

CONCLUSION

Although several molecular aspects of this mechanism have been elucidated, there is still a need for a better understanding of the factors that predispose to this disease.

High Phosphate-Induced Calcification of Vascular Smooth Muscle Cells is Associated with the TLR4/NF-κb Signaling Pathway

BACKGROUND/AIMS

Hyperphosphatemia is one of the most notable features of chronic kidney disease (CKD). Numerous epidemiological and clinical studies have found that high serum phosphate concentrations are associated with calcification in the coronary arteries. However, the mechanisms underlying the vascular calcification induced by high phosphate have not been understood fully.

METHODS

Vascular smooth muscle cells (VSMCs) were cultured in high-phosphate media to induce vascular calcification, which was detected by Alizarin red S staining. Gene expression and protein levels of differentiation markers were determined by real-time RT-PCR and western blotting, respectively. Protein levels of phosphorylated NF-κB and TLR4 were detected by western blotting, and the role of NF-κB/TLR4 was further confirmed by using an NF-κB inhibitor or TLR4 siRNA.

RESULTS

Our results showed that high-phosphate media induced obvious calcification of VSMCs. Simultaneously, VSMC differentiation was confirmed by the increased expression of bone morphogenetic protein-2 and Runt-related transcription factor 2 and decreased expression of the VSMC-specific marker SM22α, which was accompanied by the increased expression of inflammatory cytokines. Moreover, a significant upregulation of TLR4 and phosphorylated NF-κB was also detected in VSMCs with high-phosphate media. In contrast, VSMC calcification and the increased expression of inflammatory cytokines were markedly attenuated by pretreatment with TLR4 siRNA and pyrrolidine dithiocarbamic acid, an NF-κB inhibitor.

CONCLUSION

These data suggest that high-phosphate conditions directly induce vascular calcification via the activation of TLR4/NF-κB signaling in VSMCs. Moreover, inhibition of the TLR4/NF-κB signaling pathway might be a key intervention to prevent vascular calcification in patients with CKD.

Deterioration of Cerebral Oxygenation by Aortic Arch Calcification Progression in Patients Undergoing Hemodialysis: A Cross-Sectional Study

Background

Near-infrared spectroscopy revealed that the regional saturation of oxygen (rSO₂) in cerebral tissue is lower in hemodialysis (HD) patients than in healthy subjects. However, no study has examined the changes in cerebral oxygenation by aortic arch calcification (AAC) progression in HD patients.

Methods

A total of 104 HD patients were divided into four groups by AAC grade determined using chest radiography: 23 patients at grade 0, 24 at grade 1, 30 at grade 2, and 27 at grade 3. Differences in clinical parameters, including cerebral rSO₂, among AAC grades were investigated and atherosclerotic parameters affecting cerebral rSO₂ values were identified.

Results

Cerebral rSO₂ significantly decreased as AAC progressed (AAC grade 3 versus grade 0, p < 0.01 versus grade 1, p < 0.05). Multivariate logistic regression analysis was performed using parameters with p values < 0.20 in univariate analysis between cerebral rSO₂ values less than the mean and atherosclerotic parameters. AAC grades 2 and 3, serum phosphate level, and history of smoking were factors associated with the cerebral rSO₂ decrease.

Conclusions

Cerebral rSO₂ significantly decreased as AAC progressed and was independently associated with higher AAC grade, serum phosphate level, and history of smoking.

Role of different imaging modalities of vascular calcification in predicting outcomes in chronic kidney disease

Vascular calcification (VC) is common among patients with chronic kidney disease (CKD). The severity of VC is associated with increased risk of cardiovascular events and mortality. Risk factors for VC include traditional cardiovascular risk factors as well as CKD-related risk factors such as increased calcium and phosphate load. VC is observed in arteries of all sizes from small arterioles to aorta, both in the intima and the media of arterial wall. Several imaging techniques have been utilized in the evaluation of the extent and the severity of VC. Plain radiographs are simple and readily available but with the limitation of decreased sensitivity and subjective and semi-quantitative quantification methods. Mammography, especially useful among women, offers a unique way to study breast arterial calcification, which is largely a medial-type calcification. Ultrasonography is suitable for calcification in superficial arteries. Analyses of wall thickness and lumen size are also possible. Computed tomography (CT) scan, the gold standard, is the most sensitive technique for evaluation of VC. CT scan of coronary artery calcification is not only useful for cardiovascular risk stratification but also offers an accurate and an objective analysis of the severity and progression.

Assessment of the 10-year risk of cardiovascular disease among a group of patients on maintenance hemodialysis: A cross-sectional study from Cameroon

Objective

To assess the 10-year risk of cardiovascular disease and potential impacting factors among patients undergoing hemodialysis in Yaoundé, Cameroon.

Design

A cross-sectional study in January 2016.

Setting

Patients were recruited at the dialysis unit of the Yaoundé University Teaching Hospital, Cameroon.

Participants

These were hemodialysis patients aged 20 years and above, dialyzing in the above unit since at least 3 months and volunteering to be enrolled in the study.

Main outcome measures

The risk of cardiovascular disease was assessed using the Framingham risk score.

Results

We included 44 patients. The risk of cardiovascular disease ranged from less than 1% to more than 30% with a median of 12.3% (interquartile range 4.9–24.4). Twenty hemodialysis patients (45.5%) had a low risk of cardiovascular disease (<10%), 10 (22.7%), a moderate risk (10–20%), and 14 (31.8%) presented a high risk of cardiovascular disease (>20%). In multivariable linear regression analysis, duration on dialysis (adjusted β = 0.11; p = 0.003), number of weekly sessions of physical activity (adjusted β = −1.35; p = 0.018), fasting serum glucose levels (adjusted β = 4.22; p = 0.022), serum triglycerides levels (adjusted β = 5.94; p = 0.033), and serum urea levels (adjusted β = −2.08; p = 0.039) were independently impacting our patients’ risk of cardiovascular disease.

Conclusion

Around 55% of our study population presented a moderate or high risk of cardiovascular disease. Duration on dialysis, number of physical activity sessions per week, fasting serum glucose, serum triglycerides, and serum urea levels may impact our hemodialysis patients’ risk of cardiovascular disease.

Aortic Arch Calcification as a Predictor of Repeated Arteriovenous Fistula Failure within 1-Year in Hemodialysis Patients

Objectives

The aim of the study was to identify the factors associated with repeated arteriovenous fistula (AVF) failure within 1-year, especially the impact of aortic arch calcification (AAC) on patency of AVF.

Materials and Methods

We retrospectively assessed chest radiography in hemodialysis patients who had undergone initial AVF. The extent of AAC was categorized into four grades (0–3). The association between AAC grade, other clinical variables, and repeated failure of AVF was then analyzed by binary logistic regression analysis.

Results

This study included 284 patients (158 males, mean age 61.7 ± 13.1 years). Patients with higher AAC grade were older, had more frequently diabetes mellitus and cardiovascular disease, had lower diastolic blood pressure, and had higher corrected calcium and lower intact parathyroid hormone levels. In multivariate analysis, the presence of higher AAC grade (odds ratio (95% confidence interval): 2.98 (1.43–6.23); p = 0.004), lower mean corrected calcium (p = 0.017), and mean serum albumin level (p = 0.008) were associated with repeated failure of AVF.

Conclusions

The presence of higher AAC grade, lower mean corrected calcium and mean serum albumin level were independently associated with repeated AVF failure within 1 year in hemodialysis patients.

Aortic Artery and Cardiac Valve Calcification are Associated with Mortality in Chinese Hemodialysis Patients: A 3.5 Years Follow-up

BACKGROUND

This study was to investigate the relationship among aortic artery calcification (AAC), cardiac valve calcification (CVC), and mortality in maintenance hemodialysis (MHD) patients.

METHODS

All MHD patients in Shanghai Ruijin Hospital in July 2011 were included. To follow up for 42 months, clinical data, predialysis blood tests, echocardiography, and lateral lumbar X-ray plain radiography results were collected. Plasma FGF23 level was measured using a C-terminal assay.

RESULTS

Totally, 110 MHD patients were involved in this study. Of which, 64 (58.2%) patients were male, the mean age was 55.2 ± 1.4 years old, and the median dialysis duration was 29.85 (3.0-225.5) months. About 25.5% of the 110 MHD patients had CVC from echocardiography while 61.8% of the patients had visible calcification of aorta from lateral lumbar X-ray plain radiography. After 42 months follow-up, 25 (22.7%) patients died. Kaplan-Meier analysis showed that patients with AAC or CVC had a significant greater number of all-cause and cardiovascular deaths than those without. In multivariate analyses, the presence of AAC was a significant factor associated with all-cause mortality (hazard ratio [HR]: 3.149, P = 0.025) in addition to lower albumin level and lower 25-hydroxy Vitamin D (25(OH)D) level. The presence of CVC was a significant factor associated with cardiovascular mortality (HR: 3.800, P = 0.029) in addition to lower albumin level and lower 25(OH)D level.

CONCLUSION

Lateral lumbar X-ray plain radiography and echocardiography are simple methods to detect AAC and CVC in dialysis patients. The presence of AAC and CVC was independently associated with mortality in MHD patients. Regular follow-up by X-ray and echocardiography could be a useful method to stratify mortality risk in MHD patients.

Aortic arch calcification and risk of cardiovascular or all-cause and mortality in dialysis patients: A meta-analysis

Studies on aortic arch calcification (AAC) and mortality risk in maintenance dialysis patients have yielded conflicting findings. We conducted this meta-analysis to investigate the association between the presence of AAC and cardiovascular or all-cause and mortality risk in maintenance dialysis patients. Observational studies evaluating baseline AAC and cardiovascular or all-cause mortality risk in maintenance dialysis patients were searched through the PubMed and Embase, CNKI, VIP and Wanfang databases until January 2016. A total of 8 studies with 3,256 dialysis patients were identified. Compared with patients without AAC, the presence of AAC was associated with greater risk of cardiovascular mortality (hazard risk [HR] 2.30; 95% confidence intervals [CI] 1.78-2.97) and all-cause mortality (HR 1.44; 95% CI 1.19-1.75). Subgroup analyses indicated that the pooled HR for cardiovascular and all-cause mortality was 2.31 (95% CI 1.57-3.40) and 1.45 (95% CI 1.08-1.96) for the grade 2/3 AAC. Peritoneal dialysis patients with AAC had greater cardiovascular (HR 3.93 vs. HR 2.10) and all-cause mortality (HR 2.36 vs. HR 1.33) than hemodialysis patients. The AAC appears to be independently associated with excessive cardiovascular and all-cause mortality in maintenance dialysis patients. Regular follow-up AAC might be helpful to stratify mortality risk in dialysis patients.

Low serum intact parathyroid hormone level is an independent risk factor for overall mortality and major adverse cardiac and cerebrovascular events in incident dialysis patients

Abnormal bone dynamics is a major risk factor for cardiovascular disease in patients with chronic kidney disease. The level of serum intact parathyroid hormone (iPTH) is widely used as a bone dynamic marker. We investigated the effect of the mean level of serum iPTH on overall mortality and cardiovascular outcomes in incident dialysis patients.

PURPOSE

Chronic kidney disease-mineral bone disorder (CKD-MBD) is a major risk factor for cardiovascular disease (CVD) in patients with end-stage renal disease (ESRD). CKD-MBD is classified as low- or high-turnover bone disease according to the bone dynamics; both are related to vascular calcification in ESRD. To evaluate the prognostic value of abnormal serum parathyroid hormone (PTH) levels on ESRD patients, we investigated the effects of time-averaged serum intact PTH (TA-iPTH) levels on overall mortality and major adverse cardiac and cerebrovascular events (MACCEs) in incident dialysis patients.

METHODS

Four hundred thirteen patients who started dialysis between January 2009 and September 2013 at Yonsei University Health System were enrolled. The patients were divided into three groups according to TA-iPTH levels during the 12 months after the initiation of dialysis: group 1, <65 pg/ml; group 2, 65-300 pg/ml; and group 3, >300 pg/ml. Cox regression analyses were performed to determine the prognostic value of TA-iPTH for overall mortality and MACCEs.

RESULTS

The mean age of the patients was 57 ± 15 years, and 222 patients (54 %) were men. During the median follow-up of 40.8 ± 29.3 months, 49 patients (12 %) died, and MACCEs occurred in 55 patients (13 %). The multivariate Cox regression analyses demonstrated that a low TA-iPTH level was an independent risk factor for both overall mortality (group 2 as reference; group 1: hazard ratio (HR) = 2.06, 95 % confidence interval (CI) = 1.11-3.83, P = 0.023) and MACCEs (HR = 1.82, 95 % CI = 1.04-3.20, P = 0.036) in incident dialysis patients after adjustment for confounding factors.

CONCLUSION

Low serum TA-iPTH is a useful clinical marker of both overall mortality and MACCEs in patients undergoing incident dialysis, mediated by vascular calcification.

Aortic Arch Calcification Predicts Patency Loss of Arteriovenous Fistula in End-Stage Renal Disease Patients

Aortic arch calcification (AAC) is recognized as an important cardiovascular risk factor in patients with end-stage renal disease (ESRD). The aim of the study was to evaluate the impact of AAC grade on patency rates of arteriovenous fistula (AVF) in this specific population. The data of 286 ESRD patients who had an initial AVF placed were reviewed. The extent of AAC identified on chest radiography was divided into four grades (0–3). The association between AAC grade, other clinical factors, and primary patency of AVF was then analyzed by Cox proportional hazard analysis. The multivariate analysis demonstrated that the presence of AAC grade 2 (hazard ratio (95% confidence interval): 1.80 (1.15–2.84); p = 0.011) and grade 3 (3.03 (1.88–4.91); p < 0.001), and higher level of intact-parathyroid hormone (p = 0.047) were associated with primary patency loss of AVF. In subgroup analysis, which included AVF created by a surgeon assisted with preoperative vascular mapping, only AAC grade 3 (2.41 (1.45–4.00); p = 0.001), and higher intact-parathyroid hormone (p = 0.025) level were correlated with AVF patency loss. In conclusion, higher AAC grade and intact-parathyroid hormone level predicted primary patency loss of AVF in an ESRD population.