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

Moderate-severe aortic arch calcification and high serum alkaline phosphatase co-modify the risk of cardiovascular events and mortality among chronic hemodialysis patients

BACKGROUND

Patients with end-stage kidney disease undergoing chronic hemodialysis (HD) have an unparalleled risk of vascular calcification (VC) and high alkaline phosphatase (Alk-P) levels. However, whether VC contributed to the cardiovascular risk modified by serum Alk-P levels was not addressed in the population.

METHODS

A retrospective cohort study was conducted on chronic HD patients, between October 1 and December 31, 2018, with aortic arch calcification (AoAC) scores and serum Alk-P levels. Patients were categorized into four groups: non-to-mild AoAC/low Alk-P, non-to-mild AoAC/high Alk-P, moderate-to-severe AoAC/low Alk-P, and moderate-to-severe AoAC/high Alk-P. The Cox proportional hazard model and Kaplan-Meier analysis were used to evaluate the risks of major adverse cardiovascular effects (MACEs) and cardiovascular and all-cause mortality after multivariate adjustment.

RESULTS

Among 376 chronic HD patients recruited, 125 (33%) had non-to-mild AoAC/low Alk-P, 76 (20%) had non-to-mild AoAC/high Alk-P, 89 (24%) had moderate-to-severe AoAC/low Alk-P, and 86 (23%) had moderate-to-severe AoAC/high Alk-P. After 3 years of follow-up, patients with coexisting moderate-to-severe AoAC and high Alk-P had a higher risk of MACEs (aHR 1.76; 95% CI 1.06-2.92), and cardiovascular (aHR 2.49; 95% CI 1.21-5.11) and all-cause mortality (aHR 2.67; 95% CI 1.39-5.13) compared to those with non-to-mild AoAC/low Alk-P even after adjustments for significant clinical variables.

CONCLUSIONS

In chronic HD patients, moderate to severe AoAC co-existed with high Alk-P levels and enhanced the risk of MACEs and cardiovascular and all-cause mortality. Interventions to attenuate these risk factors simultaneously should be emphasized in this population.

Impact of an angulated aorto-septal relationship on cardio-cerebrovascular outcomes in patients undergoing hemodialysis

Aortic and valvular calcification are well-known risk factors for cardio-cerebrovascular events in patients undergoing hemodialysis. We investigated the clinical impact of an angulated aorto-septal angle as a result of aortic elongation due to aortic calcification on cardio-cerebrovascular outcomes in patients undergoing hemodialysis. We investigated 306 patients (mean age 65.4 years, 68% male) who underwent pre-scheduled routine echocardiography between April and September 2018. The angle between the anterior wall of the aorta and the ventricular septal surface (ASA) was quantified. We determined aortic and mitral valve calcification scores based on calcified cardiac changes; the aortic and mitral valve scores ranged between 0-9 and 0-6, respectively. The primary endpoint was a composite including cardio-cerebrovascular events and cardio-cerebrovascular death. The mean duration of dialysis among the patients in this analysis was 9.6 years. The primary endpoint was observed in 54 patients during the observational period (median 1095 days). Multivariable Cox proportional hazards analyses identified left ventricular ejection fraction (per 10% increase: hazard ratio [HR] 0.67; 95% confidential interval [CI] 0.53-0.84, P = 0.001), left ventricular mass index (per 10 g/m2 increase: HR 1.14; 95% CI 1.05-1.24, P = 0.001), ASA (per 10 degree increase: HR 0.69; 95% CI 0.54-0.88; P = 0.003), and aortic valve calcification score (HR 1.15; 95% CI 1.04-1.26, P = 0.005) as independent determinants of the primary endpoint. Kaplan-Meier analysis showed a higher incidence of the primary endpoint in patients with ASA <119.4 degrees than those with ASA ≥119.4 degrees (Log-rank P < 0.001). An angulated aorto-septal angle is an independent risk factor for cardio-cerebrovascular events and cardio-cerebrovascular death in patients undergoing hemodialysis.

Mediating effect of vascular calcification in galectin-3-related mortality in hemodialysis patients

Galectin-3 levels have been studied as a potential biomarker for predicting cardiovascular (CV) risk and mortality in hemodialysis (HD) patients. Recently, a close relationship between galectin-3 and vascular calcification (VC) has been reported. Here, we investigated the role of VC as a mediating factor in the association between galectin-3 and mortality. Serum galectin-3 and baseline aortic arch calcification (AoAC) score were measured in 477 incident HD patients. Mortality data were obtained at a median follow-up of 40 months. Causal mediation analysis was performed to examine the effect of vascular risk factors on galectin-3-related mortality. The prevalence of AoAC in HD patients was 57% (n = 272), and elevated galectin-3 levels were associated with a significantly increased risk of AoAC. When the galectin-3 level was divided by the median level of 37 ng/mL, a higher galectin group increased the risk of all-cause mortality by 1.71-fold (95% CI 1.02-2.92, p = 0.048), even after adjustment for multiple CV risk factors. Mediation analysis showed that both the direct effect of the galectin-3 on mortality (β = 0.0368, bootstrapped 95% CI [0.0113-0.0622]) and the indirect effects were significant. AoAC score and high-sensitivity CRP levels significantly mediated the association between galectin-3 and mortality (total indirect effects: β = 0.0188, bootstrapped 95% CI [0.0066-0.0352]). This study suggests that the association between high galectin-3 and mortality may be partially mediated by higher VC and inflammatory state in HD patients.

Comparative Gut Microbiome Differences between High and Low Aortic Arch Calcification Score in Patients with Chronic Diseases

Gut dysbiosis can induce chronic inflammation and contribute to atherosclerosis and vascular calcification. The aortic arch calcification (AoAC) score is a simple, noninvasive, and semiquantitative assessment tool to evaluate vascular calcification on chest radiographs. Few studies have discussed the relationship between gut microbiota and AoAC. Therefore, this study aimed to compare the microbiota composition between patients with chronic diseases and high or low AoAC scores. A total of 186 patients (118 males and 68 females) with chronic diseases, including diabetes mellitus (80.6%), hypertension (75.3%), and chronic kidney disease (48.9%), were enrolled. Gut microbiota in fecal samples were analyzed by sequencing of the 16S rRNA gene, and differences in microbial function were examined. The patients were divided into three groups according to AoAC score, including 103 patients in the low AoAC group (AoAC ≤ 3), 40 patients in the medium AoAC group (3 < AoAC ≤ 6), and 43 patients in the high AoAC group (AoAC > 6). Compared to the low AoAC group, the high AoAC group had a significantly lower microbial species diversity (Chao1 index and Shannon index) and increased microbial dysbiosis index. Beta diversity showed that the microbial community composition was significantly different among the three groups (p = 0.041, weighted UniFrac PCoA). A distinct microbial community structure was found in the patients with a low AoAC, with an increased abundance at the genus level of Agathobacter, Eubacterium coprostanoligenes group, Ruminococcaceae UCG-002, Barnesiella, Butyricimonas, Oscillibacter, Ruminococcaceae DTU089, and Oxalobacter. In addition, there was an increased relative abundance of class Bacilli in the high AoAC group. Our findings support the association between gut dysbiosis and the severity of AoAC in patients with chronic diseases.

Combined cardiomegaly and aortic arch calcification predict mortality in hemodialysis patients

INTRODUCTION

This study aimed to investigate the relationship between cardiomegaly and aortic arch calcification (AAC) and overall/cardiovascular mortality in hemodialysis patients.

METHODS

We conducted a retrospective cohort study and enrolled patients who underwent initial hemodialysis. Cardiomegaly and AAC were determined by chest radiography and classified into four groups according to cross-classification of cardiothoracic ratio (CTR) of 0.5 and lower/higher grade AAC (LGAAC/HGAAC). The relationship between these groups and mortality was then analyzed by Cox proportional hazards model.

RESULTS

In multivariate Cox regression analysis, those in CTR ≤ 0.5 and HGAAC [hazard ratio (95% confidence interval): 2.07 (1.14-3.77)], CTR > 0.5 & LGAAC [3.60 (2.07-6.25)] and CTR > 0.5 & HGAAC [3.42 (2.03-5.77)] were significantly associated with overall mortality; while those in CTR > 0.5 & LGAAC [2.81 (1.28-6.19)] and CTR > 0.5 & HGAAC [2.32 (1.09-4.95)] were significantly related to cardiovascular mortality.

CONCLUSION

Combined cardiomegaly and AAC predicted overall and cardiovascular mortality in hemodialysis patients.

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).

Oxidative phosphorylation promotes vascular calcification in chronic kidney disease

Metabolism has been reported to associate with the progression of vascular diseases. However, how vascular calcification in chronic kidney disease (CKD) is regulated by metabolic status remains poorly understood. Using a model of 5/6 nephrectomy, we demonstrated that the aortic tissues of CKD mice had a preference for using oxidative phosphorylation (OXPHOS). Both high phosphate and human uremic serum-stimulated vascular smooth muscle cells (VSMCs) had enhanced mitochondrial respiration capacity, while the glycolysis level was not significantly different. Besides, 2-deoxy-d-glucose (2-DG) exacerbated vascular calcification by upregulating OXPHOS. The activity of cytochrome c oxidase (COX) was higher in the aortic tissue of CKD mice than those of sham-operated mice. Moreover, the expression levels of COX15 were higher in CKD patients with aortic arch calcification (AAC) than those without AAC, and the AAC scores were correlated with the expression level of COX15. Suppressing COX sufficiently attenuated vascular calcification. Our findings verify the relationship between OXPHOS and calcification, and may provide potential therapeutic approaches for vascular calcification in CKD.

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.

Vascular calcification of chronic kidney disease: A brief review

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

Denosumab Recovers Aortic Arch Calcification During Long-Term Hemodialysis

Introduction

Aortic arch calcification (AoAC) is related closely to mortality risk in patients undergoing maintenance dialysis. Recent experimentally obtained data suggest that osteoprotegerin/receptor activator for nuclear factor κB ligand signal transmission plays a role in de novo chondrogenic transition of vascular cells leading to calcification that is unrelated to bone metabolism. This study investigated the long-term effects of denosumab, an osteoprotegerin mimic peptide, on AoAC.

Methods

This study examined 58 patients with an 8 year vintage of dialysis at 1 center for observational study during 2009 to 2020. Denosumab was administered to 28 patients every 6 months. Blood chemical data were used. AoAC proportions were measured using a simple but computed tomography–equivalent computer-based chest X-ray analysis (calcified pieces of areas around the aorta).

Results

Blood chemical data of the control and denosumab groups that did not differ at the start showed differences of mineral metabolism after 30 months of observation. Remarkably, the AoAC proportion increased from 29.4% to 46.25% in the control group but decreased significantly from 25.0% to 20.0% (P < 0.01) in the denosumab group. Denosumab effects on decalcification were not observed 12 months after initiation.

Conclusion

We conclude that long-term use of denosumab is effective to reverse or treat AoAC in patients undergoing hemodialysis.

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.

A Joint Evaluation of Neurohormone Vasopressin-Neurophysin II-Copeptin and Aortic Arch Calcification on Mortality Risks in Hemodialysis Patients

Objective: Systemic hypoperfusion is intricately involved in neurohormone secretion, vascular calcification (VC) related impaired vasodilation, and luminal stenosis. We aimed to conduct a joint evaluation of vasopressin-neurophysin II-copeptin peptide (VP) and advanced aortic arch calcification (AAC) on all-cause and cardiovascular (CV) mortality in maintenance hemodialysis (MHD) patients. Methods: Unadjusted and adjusted hazard ratios (aHRs) of mortality risks were analyzed for different groups of VP and AAC in 167 MHD patients. The modification effect between higher VP and advanced AAC on mortality risk was examined using an interaction product term. Results: Interactions between VP and AAC with respect to all-cause and CV mortality were statistically significant. In multivariable analysis, higher VP predicted all-cause and CV mortality [aHR: 2.2 (95% confidence interval (CI): 1.1-4.5)] and 2.6 (95% CI: 1.1-4.6), respectively. Advanced AAC was associated with incremental risks of all-cause and CV mortality [aHR: 2.1 (95% CI: 1.1-4.0)and 2.5 (95% CI: 1.0-4.3), respectively]. Patients with combined higher VP (>101.5 ng/mL) and advanced AAC were at the greatest risk of all-cause and CV mortality [aHR: 4.7 (95% CI: 1.2-16.2)and 4.9 (95% CI: 1.1-18.9), respectively]. Conclusion: Combined VP and advanced AAC predict not only all-cause but also CV death in MHD patients, and a joint evaluation is more comprehensive than single marker. In light of hypoperfusion and ischemic events in vital organs, VP and AAC could act as more robust dual marker for prognostic assessment.

Predictive performance of aortic arch calcification for clinical outcomes in patients with acute coronary syndrome that undergo percutaneous coronary intervention: A prospective clinical study

Currently, little is known regarding the predictive utility of aortic arch calcification (AAC) for clinical outcomes in patients with acute coronary syndrome (ACS) who undergo percutaneous coronary intervention (PCI). The present study was designed to investigate the predictive performance of AAC as detected by chest x-ray for clinical outcomes among ACS patients undergoing PCI.A total of 912 patients who were diagnosed as ACS and treated with PCI were included in this prospective, cohort study. All study participants received chest x-rays on admission, and a semiquantitative 4-point scale was used to assess the extent of AAC. The primary end point was defined as a composite of major adverse cardiovascular events (MACE) comprising death, nonfatal stroke, nonfatal myocardial infarction, and unplanned repeat revascularization. The key secondary end point was the composite of cardiovascular death, nonfatal stroke, and nonfatal myocardial infarction. The prognostic values of AAC were assessed in multivariate Cox-proportional hazards regression analyses adjusted for major confounders.The mean follow-up duration was 917 days and, during the follow-up period, MACE occurred in 168 (18.4%) patients. Kaplan-Meier analyses revealed significantly higher incidences of the primary and key secondary end points in patients with higher AAC grades (log-rank test; all P < .001). Multivariate Cox-proportional hazards regression analyses showed that, in comparison to AAC grade 0, the hazard ratios of AAC grades 1, 2, and 3 for predicting MACE were 1.63 (95% confidence interval [CI] 0.99-2.67), 2.15 (95% CI 1.27-3.62), and 2.88 (95% CI 1.41-5.86), respectively. The C-index of the variables, including peripheral arterial disease and serum levels of triglyceride for predicting MACE, was 0.644 (95% CI 0.600-0.687) versus 0.677 (95% CI 0.635-0.719) when AAC grades were also included; the continuous net reclassification improvement was 16.5% (8.7%-23.4%; P < .001).The extent of AAC as detected by chest x-ray is an independent predictor of MACE among ACS patients undergoing PCI. Further research is warranted to evaluate whether specific treatment strategies that are established based on AAC extent are needed for optimal risk reduction in relevant patient populations.

Abdominal aortic calcification can predict all-cause mortality and CV events in dialysis patients: A systematic review and meta-analysis

BACKGROUND

Abdominal aortic calcification (AAC) has a pretty high incidence in dialysis patients and may be associated with their prognosis. AAC can be assessed by abdominal CT or X-ray. We determined to investigate whether the occurrence of AAC is associated with all-cause mortality and cardiovascular (CV) events in dialysis patients through this meta-analysis and systematic review.

METHODS

A comprehensive literature search was conducted using the PubMed, Cochrane library, Embase, Medline databases to collect cohort studies investigating whether AAC is associated with all-cause mortality and CV events of patients, and we also searched gray articles and conferences abstracts. Meta-analysis was performed by STATA software. Pooled results were expressed as hazard ratio (HR) with corresponding 95% confidence intervals (CI). Fixed-effect models were used to pool the HR of each trial.

RESULTS

10 studies (2,724 dialysis patients) were identified. The presence of AAC was associated with increased risk for all-cause mortality among dialysis patients (HR, 2.84; 95% CI, 2.03-3.98; I2 = 9.8%; P = 0.354). Meanwhile, there was an association between AAC and increased risk for all CV events (fatal and non-fatal) in patients (HR, 2.04; 95% CI, 1.51-2.76, I2 = 44.6%; P = 0.125). 3 studies presented their endpoint as CV mortality, and the pooled HR was 2.46 (95%CI 1.38-4.40; I2 = 0.0%; P = 0.952). There were also 2 studies that reported their primary endpoint as all-cause mortality and CV events, and the pooled HR was 5.72 (95% CI 3.24-10.10; I2 = 0.0%; P = 0.453).

CONCLUSIONS

Among patients treated with dialysis, AAC is associated with adverse outcomes, including all-cause mortality and CV events (fatal and non-fatal). The abdominal X-ray or CT scan can be used as a useful added method to evaluate the patient's calcification. This may provide reasonable data for estimating the risk of adverse events in dialysis patients, which is helpful in guiding clinical treatment and improving the prognosis of dialysis patients.

Phosphorus and mortality risk in end-stage renal disease: A meta-analysis

BACKGROUND

Studies on the association of abnormal serum phosphorus level with all-cause mortality in patients with end-stage renal disease (ESRD) have yielded inconsistent results.

OBJECTIVE

To evaluate the association of abnormal serum phosphorus level with all-cause mortality in patients with ESRD requiring dialysis by conducting a meta-analysis.

METHODS

Pubmed and Embase databases were searched through March 2017 to identify all observational studies that assessed the association between abnormal serum phosphorus level and all-cause mortality risk in patients with ESRD requiring dialysis. Pooled hazard risk (HR) with 95% confidence interval (CI) was calculated for the highest versus referent phosphorus category and lower versus referent phosphorus category, separately.

RESULTS

Nine cohort studies were eligible for analysis. During 12 to 97.6months follow-up duration, 24,463 death events occurred among 1,992,869 ESRD patients. Meta-analysis showed that the pooled HR of all-cause mortality was 1.16 (95% CI 1.06-1.28) for the lower versus referent serum phosphorus category. Similarly, patients with highest serum phosphorus levels were associated with an increased risk of all-cause mortality (HR 1.39; 95% CI 1.31-1.47) compared with those in the referent phosphorus category. Subgroup analyses revealed that the effect of phosphorus on the all-cause mortality risk appeared to be stronger within 2years follow-up.

CONCLUSIONS

Both very high and very low values of phosphorus are independently associated with an increased risk for all-cause mortality in ESRD patients requiring dialysis. This meta-analysis highlighted a non-linear association of serum phosphorus with all-cause mortality among dialysis-dependent ESRD patients.

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.