Association of Cardiac Valvular Calcifications and C-Reactive Protein With Cardiovascular Mortality in Incident Hemodialysis Patients: A Japanese Cohort Study

The association of peritoneal dialysis and hemodialysis on mitral and aortic valve calcification associated mortality: a meta-analysis

Cardiac valve calcification (CVC), characterized by the accumulation of calcium in the heart valves, is highly prevalent among patients undergoing dialysis. This meta-analysis aimed to provide an updated summary of recent studies on the prognostic value of CVC in patients undergoing dialysis. We conducted a search of PubMed, Embase, and Web of Science to identify observational studies investigating cardiovascular or all-cause mortality associated with CVC in dialysis patients until March 2023. Hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) were calculated for the meta-analysis, and the strength and significance of the associations between CVC and mortality outcomes in dialysis patients were assessed. From 6218 initially identified studies, we included 10 critical studies with a total of 3376 dialysis patients in a further meta-analysis. Pooled analyses demonstrated a significant association between CVC and an elevated risk of all-cause and cardiovascular mortality in dialysis patients. In our study, we discovered HRs of 1.592 (95% CI 1.410-1.797) for all-cause mortality and 2.444 (95% CI 1.632-3.659) for cardiovascular mortality. Furthermore, subgroup analysis revealed elevated all-cause mortality among patients with mitral valve calcification (HR 1.572; 95% CI 1.200-2.060) compared to those with aortic valve calcification (HR 1.456; 95% CI 1.105-1.917). Similarly, patients undergoing peritoneal dialysis faced a greater risk for all-cause mortality (HR 2.094; 95% CI 1.374-3.191) than those on hemodialysis (HR 1.553; 95% CI 1.369-1.763). This highlights the possibility of CVC being an independent risk factor for dialysis patients, particularly in relation to mitral valve calcification or peritoneal dialysis.

Serum magnesium level and cardiac valve calcification in hemodialysis patients

INTRODUCTION

Cardiac valve calcification is closely related to cardiovascular disease. The aim of this study was to investigate the magnesium level and cardiac valve calcification in hemodialysis patients.

METHODS

A cross-sectional study was conducted in 105 maintenance hemodialysis patients with complete follow-up data from June 2020 to May 2021 in Beijing Tsinghua Changgung Hospital, Tsinghua University. Baseline data, including sex, age, primary disease, liver and kidney function, electrolytes and parathyroid hormone, were recorded. According to their echocardiograms, patients were divided into a cardiac valve calcification group and a noncardiac valve calcification group, and the correlations between valve calcification and clinical data were analyzed.

RESULTS

Of 105 patients under hemodialysis, 60 (56.6%) were male, with an average age of 62.1 ± 13.5 years and a mean dialysis duration of 58.8 ± 45.4 months. The majority of primary renal diseases were diabetic nephropathy (55, 51.9%). Approximately 64.8% of the 105 maintenance hemodialysis patients had cardiac valve calcification, and 35.2% were in the noncardiac valve calcification group. The independent t test and the chi-square test analysis showed that the cardiac valve calcification group had older age, higher smoking rate, diabetes mellitus, lower extremity arterial occlusion, coronary heart disease, and coronary artery calcification ratio but lower parathyroid hormone, serum calcium, serum magnesium, albumin, prealbumin, and high-density lipoprotein cholesterol levels (P < 0.05). Logistic regression analysis showed that age, diabetes mellitus, coronary artery calcification, lower serum magnesium, lower serum calcium, and lower parathyroid hormone levels were associated with valve calcification.

CONCLUSION

The presence of cardiac valve calcification was associated with age, calcium, phosphorus and lower magnesium level. These factors we should pay more attention in clinical practice.

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.

Overexpression of microRNA-93-5p and microRNA-374a-5p Suppresses the Osteogenic Differentiation and Mineralization of Human Aortic Valvular Interstitial Cells Through the BMP2/Smad1/5/RUNX2 Signaling Pathway

ABSTRACT

Aortic valve calcification commonly occurs in patients with chronic kidney disease (CKD). However, the regulatory functions of microRNAs (miRNAs/miRs) in the osteogenic differentiation of human aortic valvular interstitial cells (hAVICs) in patients with CKD remain largely unknown. This study aimed to explore the functional role and underlying mechanisms of miR-93-5p and miR-374a-5p in the osteogenic differentiation of hAVICs. For this purpose, hAVICs calcification was induced with high-calcium/high-phosphate medium and the expression levels of miR-93-5p and miR-374a-5p were determined using bioinformatics assay. Alizarin red staining, intracellular calcium content, and alkaline phosphatase activity were used to evaluate calcification. The expression levels of bone morphogenetic protein-2 (BMP2), runt-related transcription factor 2 (Runx2), and phosphorylated (p)-Smad1/5 were detected by luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and western blot analysis. The results revealed that the expression levels of miR-93-5p and miR-374a-5p were significantly decreased in hAVICs in response to high-calcium/high-phosphate medium. The overexpression of miR-93-5p and miR-374a-5p effectively suppressed the high-calcium/high-phosphate-induced calcification and osteogenic differentiation makers. Mechanistically, the overexpression of miR-93-5p and miR-374a-5p inhibits osteogenic differentiation by regulating the BMP2/Smad1/5/Runx2 signaling pathway. Taken together, this study indicates that miR-93-5p and miR-374a-5p suppress the osteogenic differentiation of hAVICs associated with calcium-phosphate metabolic dyshomeostasis through the inhibition of the BMP2/Smad1/5/Runx2 signaling pathway.

Tissue Sodium Accumulation Induces Organ Inflammation and Injury in Chronic Kidney Disease

High salt intake is a primary cause of over-hydration in chronic kidney disease (CKD) patients. Inflammatory markers are predictors of CKD mortality; however, the pathogenesis of inflammation remains unclear. Sodium storage in tissues has recently emerged as an issue of concern. The binding of sodium to tissue glycosaminoglycans and its subsequent release regulates local tonicity. Many cell types express tonicity-responsive enhancer-binding protein (TonEBP), which is activated in a tonicity-dependent or tonicity-independent manner. Macrophage infiltration was observed in the heart, peritoneal wall, and para-aortic tissues in salt-loading subtotal nephrectomized mice, whereas macrophages were not prominent in tap water-loaded subtotal nephrectomized mice. TonEBP was increased in the heart and peritoneal wall, leading to the upregulation of inflammatory mediators associated with cardiac fibrosis and peritoneal membrane dysfunction, respectively. Reducing salt loading by a diuretic treatment or changing to tap water attenuated macrophage infiltration, TonEBP expression, and inflammatory marker expression. The role of TonEBP may be crucial during the cardiac fibrosis and peritoneal deterioration processes induced by sodium overload. Anti-interleukin-6 therapy improved cardiac inflammation and fibrosis and peritoneal membrane dysfunction. Further studies are necessary to establish a strategy to regulate organ dysfunction induced by TonEBP activation in CKD patients.

Prognosis of Heart Valve Calcification on Cardiovascular Events in Hemodialysis Patients without Central Venous Catheters

INTRODUCTION

Heart valvular calcification (HVC) is an important predictor of cardiovascular events (CEs) and all-cause mortality in dialysis patients. Patients in the early stage of dialysis or those with central venous catheters (CVC) are also at high risk of cardiovascular and all-cause mortality. It could be a confounding factor for the prognosis of HVC on CE.

METHODS

From March 2017 to April 2022, the prognosis of HVC on CE and all-cause mortality was studied retrospectively in 158 hemodialysis (HD) patients who used arteriovenous fistulas or arteriovenous grafts as vascular access and entered HD for more than 12 months.

RESULTS

Out of 158 patients, 70 (44.3%) were diagnosed with HVC via echocardiography. A total of 180 CEs occurred during follow-up. Among them, acute heart failure accounted for 62.66%, and its prevalence was significantly higher in the HVC group than that in the non-HVC group (p < 0.0001). The cumulative incidence of CE-free survival in the HVC group was significantly lower than that in the non-HVC group (p = 0.030). Only 11 patients died, and there was no significant difference in all-cause mortality between the two groups (p = 0.560). Multivariate COX regression analyses showed that HD vintage, mitral valve calcification, and aortic valve regurgitation (AR)/aortic valve stenosis (AS) but not aortic valve calcification were risk factors for CE (p < 0.05).

CONCLUSION

After excluding the factors of the early stage of HD and CVC, HVC remained a predictor of adverse CE in HD patients.

Interleukin-6 blockade reduces salt-induced cardiac inflammation and fibrosis in subtotal nephrectomized mice

Cardiovascular disease is the most common comorbidity in patients with chronic kidney disease (CKD), affecting both their prognosis and quality of life. Cardiac fibrosis is common in patients with CKD with left ventricular diastolic dysfunction, and it is associated with increased risk of heart failure and mortality. Recent evidence suggests that high salt intake activates immune responses associated with local accumulation of sodium. We reported that high salt intake promotes cardiac inflammation in subtotal nephrectomized (Nx) mice. We investigated the effects of administration of MR16-1, a rat anti-mouse monoclonal interleukin (IL)-6 receptor antibody, in Nx mice with salt loading (Nx-salt). Expression of monocyte chemoattractant protein-1, tumor necrosis factor-α, IL-1β, and IL-6 mRNAs and macrophage infiltration was significantly reduced in the heart of Nx-salt mice treated with MR16-1 (Nx-salt-MR16-1) compared with Nx-salt mice treated with control rat rat IgG1 (Nx-salt-rat IgG1). Correspondingly, cardiac fibrosis was significantly attenuated in Nx-salt-MR16-1 mice compared with Nx-salt-rat IgG1 mice. Furthermore, in the heart of Nx-salt-MR16-1 mice, expression of mRNA for nicotinamide adenine dinucleotide phosphate oxidase-2, an oxidative stress marker, was significantly downregulated compared with Nx-salt-rat IgG1 mice. Increases in cardiac metabolites, including histidine and γ-butyrobetaine, were also reversed by IL-6 blockade treatment. In conclusion, IL-6 blockade exerts anti-inflammatory, antifibrotic, and partial antioxidative effects in the heart of Nx-salt mice.NEW & NOTEWORTHY In the present study, IL-6 blockade exerted anti-inflammatory, antifibrotic, and partial antioxidative effects on the hearts of mice with CKD on a high-salt diet. Therefore, IL-6 potentially mediates cardiac fibrosis induced by high salt intake in patients with CKD, a finding with therapeutic implications. Of note, the next therapeutic implication may simply be the reinforcement of low-salt diets or diuretics and further research on the anti-inflammatory effects of these measures rather than IL-6 blockade with high-salt diet.

Cardiac valve calcification is associated with mortality in hemodialysis patients: a retrospective cohort study

Background

Cardiac valve calcification (CVC) is common in end-stage renal disease (ESRD). We investigated the effect of CVC on all-cause and cardiovascular (CV) mortality in maintenance hemodialysis (MHD) patients.

Methods

A retrospective cohort study was conducted on 434 hemodialysis patients who underwent echocardiography for qualitative assessment of valve calcification with complete follow-up data from January 1, 2014, to April 30, 2021. The baseline data between the CVC and non-CVC groups were compared. The Kaplan–Meier method was used to analyse all-cause and cardiovascular mortality. The association of CVC with all-cause and cardiovascular mortality was evaluated using multivariate Cox regression analysis.

Results

Overall, 27.2% of patients had mitral valve calcification (MVC), and 31.8% had aortic valve calcification (AVC) on echocardiography. Patients with CVC showed significantly higher all-cause (log-rank P < 0.001) and cardiovascular (log-rank P < 0.001) mortality rates than patients without CVC. In multivariate regression analyses, MVC (HR: 1.517, P = 0.010) and AVC (HR: 1.433, P = 0.028) were significant factors associated with all-cause mortality. MVC (HR: 2.340, P < 0.001) and AVC (HR: 2.410, P < 0.001) were also significant factors associated with cardiovascular mortality.

Conclusions

MVC and AVC increased the risk of all-cause and cardiovascular mortality in MHD patients. Regular follow-up with echocardiography could be a useful method for risk stratification in MHD patients.

An echocardiography-derived calcium score as a predictor of major adverse cardiovascular events in peritoneal dialysis patients-A prospective cohort study

BACKGROUND

An echocardiography-derived calcium score (ECS) has been shown to predict cardiovascular (CV) mortality in the general population but has not been utilized in the dialysis population.

METHODS

We conducted a prospective cohort study including 125 prevalent PD patients. Two blinded and independent echocardiographers determined the ECS for each subject at baseline. The primary outcome was the three-point major adverse cardiovascular events (MACE) which is a composite outcome comprising CV death, non-fatal myocardial infarction and non-fatal stroke. The secondary outcome was all-cause mortality.

RESULTS

The mean age was 61 ± 13 years. The median follow-up duration was 40 months (range 1-50). Seventy six (60.8%) of the subjects had diabetes mellitus (DM). The median duration of dialysis was 32 (IQR 16-54) months. The incidences of MACE and all-cause mortality were 13.0 per 100 patient-years and 18.3 per 100 patient-years. Multivariate Cox regression analysis identified the following three independent predictors of MACE: ECS (HR 1.253/unit increase in ECS, 95% CI 1.014-1.547, p = .036), DM (HR 2.467, 95% CI 1.014-6.005, p = .047) and pre-existing cardiovascular disease (CVD) (HR 2.441, 95% CI 1.261-4.728, p = .008); and the following two predictors of all-cause mortality: pre-existing CVD (HR 2.156, 95% CI 1.251-3.714, p = .006) and serum albumin (HR 0.887/g/L increase in serum albumin, 95% CI 0.839-0.937, p < .001).

CONCLUSION

The ECS appears to be a significant predictor of MACE in PD patients independently of DM and pre-existing CVD.

Valvular Calcific Deposits and Mortality in Peritoneal Dialysis Patients: A Propensity Score-Matched Cohort Analysis

OBJECTIVE

This study aimed to compare mortality between peritoneal dialysis (PD) patients with and without cardiac valve calcification (CVC).

METHODS

Patients undergoing PD at the dialysis center of the Second Affiliated Hospital of Soochow University from January 1, 2009, to June 31, 2016, were included and followed through December 31, 2018. The inclusion criteria were (1) age ≥18 years and (2) PD vintage ≥1 month. The exclusion criteria were (1) a history of hemodialysis or renal transplantation before PD; (2) diagnosed congenital heart disease, rheumatic heart disease, or hyperthyroid heart disease; and (3) loss to follow-up. Differences in mortality rates were compared using a Fine-Gray proportional hazards model.

RESULTS

A total of 310 patient cases were included in this study, including 237 cases without CVC (non-CVC group). The CVC group included 59 cases with aortic valve calcification (AVC), 6 cases with mitral valve calcification (MVC), and 8 cases of AVC associated with MVC. After propensity score matching, 68 pairs were selected. The multivariate competing risk regression analysis revealed that age (hazard ratio [HR]: 1.06, 95% confidence interval [95% CI]: 1.03-1.10, p < 0.001) and CVC group (HR: 1.83, 95% CI: 1.04-3.20, p < 0.05) were independent risk factors associated with mortality. No significant difference was observed in technique survival between the 2 groups.

CONCLUSION

CVC is an independent risk factor for mortality in PD patients.

All-cause and cardiovascular mortality in patients undergoing hemodialysis with aortic sclerosis and mild-to-moderate aortic stenosis: A cohort study

BACKGROUND AND AIMS

Mild-to-moderate aortic stenosis (AS) and aortic sclerosis, a precursor of AS, are associated with mortality in the general population; however, their association in patients undergoing hemodialysis with higher morbidity of AS is unknown. Thus, we investigated the mortality of aortic sclerosis and mild-to-moderate AS in patients undergoing hemodialysis.

METHODS

This was a retrospective multicenter cohort study of consecutive patients undergoing hemodialysis at nine dialysis facilities who underwent screening echocardiography between January 2008 and December 2019. We investigated the mortality of patients with aortic sclerosis or mild-to-moderate AS using multivariable Cox proportional hazards regression.

RESULTS

Among 1,878 patients undergoing hemodialysis, those with normal aortic valves, aortic sclerosis, mild AS, moderate AS, severe AS, and prosthetic aortic valves were 844 (45%), 793 (42%), 161 (8.6%), 38 (2.0%), 11 (0.6%), and 31 (1.7%), respectively. After excluding patients with severe AS and prosthetic aortic valves, we performed comparative analysis on 1,836 patients (mean age, 67 years; 66% male). In a median follow-up of 3.6 years, crude death rates (per 100 person-years) were 5.2, 10.6, and 13.0 in patients with normal aortic valves, aortic sclerosis, and mild-to-moderate AS, respectively. Compared with normal aortic valves, both aortic sclerosis and mild-to-moderate AS were associated with all-cause and cardiovascular death: adjusted hazard ratios (95% confidence intervals) were 1.36 (1.13-1.65) and 1.36 (1.02-1.80) for all-cause death; and 1.52 (1.06-2.17) and 1.74 (1.04-2.92) for cardiovascular death, respectively.

CONCLUSIONS

Aortic sclerosis and mild-to-moderate AS were independent risk factors for all-cause and cardiovascular death in patients undergoing hemodialysis.

Exploring the relation between mortality and left ventricular structure and function in stable hemodialysis treated patients, a longitudinal multicenter cohort study

Left ventricular (LV) structure and function anomalies are frequent during the CKD continuum and are associated with increased risk of mortality. Cross section and longitudinal ultrasound data are available for advanced CKD and transition to ESKD. Less information is available about LV changes during stable, long-term hemodialysis (HD) treatment. All stable HD patients from 9 HD centers (1034 patients, 671 males, age 58.71 ± 12.94 years) have been enrolled in January 2015. The cohort was followed-up for 4 years, kidney transplantation or death. Yearly, two-dimensional and M-mode continuous and Pulse Doppler echocardiography were performed. During the follow-up, the prevalence of cardiovascular comorbidities significantly increased (p < 0.0001), coronary artery disease (CAD) from 73.5 to 88.8%, peripheral artery disease (PAD) from 29 to 40.9%, cerebral vascular disease (CVD) from 20.4 to 30.8%, heart valves calcification (VC) from 65.6 to 89.3% and left ventricular hypertrophy (LVH) from 67.6 to 76.5%. The mortality risk increased with the presence of CAD (1.59-fold), PAD (1.61-fold), CVD (1.59-fold), and VC (1.77-fold). Mortality risk was increased in those with LVEF < 50% (LVEF 40–49% 1.5-fold and LVEF < 40% 2.3 fold). Among the survivors of the first year, LVEF varied (> 5% decrease, > 5% increase and ± 5% variations). More than 5% increase of LVEF was associated with higher mortality risk (crude 1.5-fold, adjusted 1.43-fold) compared to stationary EF (p = 0.001). Cardiovascular disease progresses during stable long-term HD therapy and increases mortality risk. HF becomes highly prevalent but only HF with decreased LVEF < 50% is associated with increased risk of mortality.

Relationship between Serum Uric Acid and Mortality Risk in Hemodialysis Patients: A Multicenter Prospective Cohort Study

BACKGROUND

Several studies have reported that low serum uric acid (SUA) levels are related to increased risk of mortality in maintenance hemodialysis (MHD) patients. However, the possible detrimental effects of high SUA on the mortality risk have not been well examined. Moreover, the possible effect modifiers for the SUA-mortality association have not been fully investigated. To address the aforementioned gap, we aimed to explore the nonlinear relationship between SUA levels and all-cause and cardiovascular disease (CVD) mortality risk, and to examine any possible effect modifiers in MHD patients.

METHODS

We conducted a multicenter, prospective cohort study among 1,018 MHD patients from 8 hemodialysis centers. The primary outcome was all-cause mortality, and the secondary outcomes were CVD mortality and non-CVD mortality.

RESULTS

The mean value for SUA in the total population was 8.5 ± 1.9 mg/dL. The lowest and highest quintiles of SUA were <7.0 and >10.1 mg/dL, respectively. Over a median follow-up of 45.6 months, 343 deaths were recorded, of which 202 (58.9%) were due to CVD. When SUA was assessed as quintiles, a significantly higher risk of all-cause mortality was found in patients in quintile 1 (<7.0 mg/dL; hazard ratio [HR], 1.33; 95% confidence interval [CI]: 1.02-1.73) or quintile 5 (≥10.1 mg/dL; HR, 1.47; 95% CI: 1.09-2.00), compared to those in quintiles 2-4 (7-10.1 mg/dL). Moreover, the U-shaped SUA-mortality association was mainly found in those with lower C-reactive protein levels (<3 compared with ≥3 mg/L; p for interaction = 0.018). Similar trends were found for CVD mortality and non-CVD mortality.

CONCLUSION

There was a U-shaped relationship between SUA levels and the risk of all-cause mortality, CVD mortality, and non-CVD mortality in MHD patients.

A Rat Model with Multivalve Calcification Induced by Subtotal Nephrectomy and High-Phosphorus Diet

Background

Chronic kidney disease (CKD) with known valve calcification (VC) places individuals at high risk of cardiovascular disease. The study of VC in CKD is challenging due to the lack of a suitable research model. Here, we established a rat model of multivalve calcification induced by subtotal nephrectomy and a high-phosphate (HP) diet and analyzed the valve characteristics.

Methods

We established a CKD model in Sprague-Dawley rats by performing 5/6 nephrectomy (5/6Nx) followed by feeding with chow containing different phosphate concentrations for 8, 12, or 16 weeks. The rats were divided into 4 groups: sham+normal phosphate (NP, 0.9% P), sham+high phosphate (HP, 2.0% P), 5/6Nx+NP, and 5/6Nx+HP. Serum creatinine (Scr), blood urea nitrogen (BUN), parathyroid hormone (PTH), calcium, phosphorus, and 24-h urine protein levels were investigated. Pathological examinations included histological characterization, safranin staining, Alcian blue staining, and von Kossa staining at different time points. Using nanoanalytical electron microscopy, we examined valves from rats in the 5/6Nx+HP and sham+HP groups and detected spherical particles using energy-dispersive spectroscopy (EDS) to observe microscopic changes in the valves. In addition, the calcified tissues were analyzed for phase and crystallization properties using an X-ray powder diffractometer.

Results

The rats in the 5/6Nx+HP and 5/6Nx+NP groups presented with increased levels of Scr, BUN, and 24-h urine protein compared with those of the rats in the sham+HP and sham+NP groups. High levels of PTH were observed, and hematoxylin and eosin staining and immunohistochemistry for proliferating cell nuclear antigen showed parathyroid hyperplasia in rats in the 5/6Nx+HP group but not in the 5/6Nx+NP group. In rats in the 5/6Nx+HP group, extracellular matrix glycosylation was observed in the aortic valve in the 12th week and the mitral valve in the 16th week. In the 16th week, chondrocytes appeared in the aortic valve, as confirmed by immunofluorescence and Western blotting. Calcified particles mainly composed of phosphorus and calcium were observed in both the aortic and mitral valves by transmission electron microscopy and scanning electron microscopy (SEM). The main mineral component of the calcified aortic valve particles was hydroxyapatite [Ca₅(PO₄)₃(OH)], as shown by X-ray diffraction. However, there were no obvious differences in heart function between rats in the 5/6Nx+HP and sham+HP groups.

Conclusions

Our findings demonstrate that multivalve calcification is involved in CKD following 16-week HP and that hydroxyapatite [Ca₅(PO₄)₃(OH)] is the main component of the calcified aortic valve particles of rats in the 5/6Nx+HP group.

Association of aortic valve calcification with carotid artery lesions and peripheral artery disease in patients with chronic kidney disease: a cross-sectional study

Background

Patients with chronic kidney disease (CKD) reportedly have a high prevalence of aortic valve calcification (AVC). In population-based studies, AVC is considered a manifestation of systemic atherosclerosis. The association of AVC with atherosclerotic lesions has not been fully investigated in predialysis patients. The present study was performed to determine whether carotid artery lesions and peripheral artery disease (PAD) are associated with AVC in patients with CKD not on dialysis.

Methods

In total, 749 patients were included in this cross-sectional study. AVC was evaluated using echocardiography. Carotid artery lesions including carotid artery plaque (CAP) and PAD were simultaneously examined in each patient. A logistic regression analysis was applied to determine the factors associated with AVC.

Results

AVC, CAP, and PAD were found in 201, 583, and 123 patients, respectively. In the multivariable analyses adjusted for covariates including the estimated glomerular filtration rate and makers of mineral metabolism (serum calcium, serum phosphorus, parathyroid hormone, 1,25-dihydroxyvitamin D, and fibroblast growth factor 23), AVC was significantly associated with the presence of CAP [odds ratio (OR), 3.37; 95% confidence interval (CI), 1.43–7.95], the presence of PAD (OR, 1.76; 95% CI, 1.10–2.81), the CAP score (per 1.0-point increase) (OR, 1.06; 95% CI, 1.02–1.11), and the ankle-brachial blood pressure index (per 0.1-point increase) (OR, 0.83; 95% CI, 0.72–0.95).

Conclusions

AVC was associated with atherosclerotic lesions independent of kidney function and mineral metabolism. We consider that this association between AVC and atherosclerosis might reflect the burden of shared atherosclerotic risk factors.

The influence of cardiac valvular calcification on all-cause and cardiovascular mortality in maintenance hemodialysis patients

OBJECTIVE

To investigate the effect of cardiac valve calcification (CVC) on all-cause and cardiovascular mortality in maintenance hemodialysis (MHD) patients.

METHODS

A retrospective cohort study was conducted in 183 long-term hemodialysis patients with complete follow-up data from January 1, 2012, to December 30, 2015. The baseline data between CVC and non-CVC groups were compared. Kaplan-Meier method was used to analyze all-cause and cardiovascular mortality. The effect of CVC on prognosis was analyzed using the Cox proportional hazard regression model and subgroup analysis.

RESULTS

Among 183 patients under hemodialysis, 104 (56.8%) were males, with an average age of 56.1 ± 17.0 years and 68 (37.2%) were complicated with valvular calcification. The median follow-up period was 30.8 months. All-cause and cardiovascular mortality were 50% vs. 14.8% and 25% vs. 7.0% in the CVC and non-CVC groups, respectively (P < 0.05). Kaplan-Meier indicated that differences in all-cause and cardiovascular mortality were statistically significant between the two groups (P < 0.001). Cox regression analysis showed that CVC significantly increased all-cause (hazards ratio [HR] 2.161 [1.083-4.315]) and cardiovascular mortality (3.435 [1.222-9.651]) after adjusting for multiple factors. Meanwhile, CVC also increases the incidence of new-onset cardiovascular events. Subgroup analysis revealed that all-cause and cardiovascular mortality were significantly higher in patients with aortic valve calcification (AVC) than in patients with mitral valve calcification (MVC). Multivariate calibration showed that AVC increased the risk of cardiovascular death (HR 5.486 [1.802-16.702]) (P < 0.05), whereas MVC did not. By further comparing the echocardiographic data of the two groups, the incidence of LVH and pulmonary hypertension in the AVC group was significantly higher than that in the MVC group.

CONCLUSION

Valve calcification increases the risk of all-cause and cardiovascular mortality in MHD patients, also new-onset cardiovascular events, and aortic valve calcification contributes more to the risk of cardiovascular mortality.

Aortic Valve Calcium Associates with All-Cause Mortality Independent of Coronary Artery Calcium and Inflammation in Patients with End-Stage Renal Disease

BACKGROUND

Aortic valve calcium (AVC) and coronary artery calcium (CAC) are common complications in end-stage renal disease (ESRD). We investigated the prognostic significance of overlapping presence of AVC and CAC, and whether AVC was associated with all-cause mortality independent of the presence of CAC in ESRD.

METHODS

259 ESRD patients (median age 55 years, 67% males) undergoing cardiac computed tomography were included. Framingham risk score (FRS), presence of cardiovascular disease (CVD), statin use, nutritional status and other relevant laboratory data were determined at baseline. During follow-up for median 36 months, 44 patients died, and 68 patients underwent renal transplantation.

RESULTS

The baseline overlap presence of AVC and CAC was 37%. Multivariate regression analysis showed that FRS (odds ratio (OR) 2.25; 95% confidence interval (95% CI), 1.43-3.55) and CAC score (OR (95% CI), 2.18 (1.34-3.59)) were independent determinants of AVC. In competing-risk regression models adjusted for presence of CAC, inflammation, nutritional status, CVD, FRS and statin use, AVC remained independently associated with all-cause mortality (sub-hazard ratio (95% CI), 2.57 (1.20-5.51)).

CONCLUSIONS

The overlap of AVC and CAC was 37% in this ESRD cohort. AVC was associated with increased all-cause mortality independent of presence of CAC, traditional risk factors and inflammation.

Comparison of the effects of lanthanum carbonate and calcium carbonate on the progression of cardiac valvular calcification after initiation of hemodialysis

Background

Although mineral metabolism disorder influences cardiac valvular calcification (CVC), few previous studies have examined the effects of non-calcium-containing and calcium-containing phosphate binders on CVC in maintenance hemodialysis patients. The aim of the present study was to compare the effects of lanthanum carbonate (LC) with calcium carbonate (CC) on the progression of CVC in patients who initiated maintenance hemodialysis and to investigate clinical factors related to CVC.

Methods

The current study included 50 subjects (mean age 65 years, 72% males) from our previous randomized controlled trial (LC group, N = 24; CC group, N = 26). CVC was evaluated as CVC score (CVCS) using echocardiography at baseline and 18 months after initiation of hemodialysis. We compared CVCS and the changes between the two groups. We also analyzed the associations between CVCS and any other clinical factors including arterial plaque score (PS) and serum phosphorus levels.

Results

Baseline characteristics of study participants including CVCS were almost comparable between the two groups. At 18 months, there were no significant differences in mineral metabolic markers or CVCS between the two groups, and CVCS were significantly correlated with PS (r = 0.39, p < 0.01). Furthermore, changes in CVCS were significantly correlated with average phosphorus levels (r = 0.36, p < 0.05), which were significantly higher in high serum phosphorus and high PS group compared to low serum phosphorus and low PS group (p < 0.05).

Conclusions

In the present study, there were no significant differences between LC and CC with regard to progression of CVC. However, serum phosphorus levels and arterial plaque seem to be important for the progression and formation of CVC in hemodialysis patients.

Impact of Hypothyroidism on Echocardiographic Characteristics of Patients With Heart Valve Disease: A Single-Center Propensity Score-Based Study

Background: Hypothyroidism is known to be correlated with multiple heart diseases. However, the influence of hypothyroidism on the patients with heart valve disease (HVD) is still unclear. The purpose of our study was to investigate the impact of hypothyroidism on echocardiographic characteristics of patients with heart valve disease. Methods: We conducted a retrospective cohort study which included 2,128 patients with HVD, and they were divided into euthyroid, subclinical hypothyroidism (SCHypoT), and overt hypothyroidism (OHypoT) group. Echocardiographic characteristics before and after valve surgery between groups were compared by using propensity score (PS) analysis. Kaplan-Meier analysis was used to compare the percent of recovery of left atrial (LA) enlargement between groups. Results: Overall, 463 patients had hypothyroidism (404 SCHypoT patients and 59 OHypoT patients), and 1,665 patients were euthyroid. At baseline, hypothyroidism was associated with significantly higher left atrial diameter (LAD), interventricular septum thickness, left ventricular posterior wall thickness, pulmonary artery systolic pressure, and lower left ventricular ejection fraction. After valve surgery, only LAD remained significantly higher in the patients with hypothyroidism. Additionally, patients with hypothyroidism had a significantly lower recovery rate of LA enlargement after valve surgery compared with euthyroid patients. Conclusion: Hypothyroidism was associated with a larger LAD in patients with HVD before and after surgery, which may suggest that hypothyroidism is a risk factor of LA enlargement of HVD. Besides, hypothyroidism was associated with a significantly lower recovery rate of LA enlargement after valve surgery.

Impact of C-reactive protein on osteo-/chondrogenic transdifferentiation and calcification of vascular smooth muscle cells

Medial vascular calcification occurs during the aging process and is strongly accelerated by chronic kidney disease (CKD). Elevated C-reactive protein (CRP) levels are associated with vascular calcification, cardiovascular events and mortality in CKD patients. CRP is an important promoter of vascular inflammation. Inflammatory processes are critically involved in initiation and progression of vascular calcification. Thus, the present study explored a possible impact of CRP on vascular calcification. We found that CRP promoted osteo-/chondrogenic transdifferentiation and aggravated phosphate-induced osteo-/chondrogenic transdifferentiation and calcification of primary human aortic smooth muscle cells (HAoSMCs). These effects were paralleled by increased cellular oxidative stress and corresponding pro-calcific downstream-signaling. Antioxidants or p38 MAPK inhibition suppressed CRP-induced osteo-/chondrogenic signaling and mineralization. Furthermore, silencing of Fc fragment of IgG receptor IIa (FCGR2A) blunted the pro-calcific effects of CRP. Vascular CRP expression was increased in the klotho-hypomorphic mouse model of aging as well as in HAoSMCs during calcifying conditions. In conclusion, CRP augments osteo-/chondrogenic transdifferentiation of vascular smooth muscle cells through mechanisms involving FCGR2A-dependent induction of oxidative stress. Thus, systemic inflammation may actively contribute to the progression of vascular calcification.

Inhibition of acetylation of histones 3 and 4 attenuates aortic valve calcification

Aortic valve calcification develops in patients with chronic kidney disease who have calcium and phosphate metabolic disorders and poor prognoses. There is no effective treatment except valve replacement. However, metabolic disorders put patients at high risk for surgery. Increased acetylation of histones 3 and 4 is present in interstitial cells from human calcific aortic valves, but whether it is involved in aortic valve calcification has not been studied. In this study, we found that treating cultured porcine aortic valve interstitial cells with a high-calcium/high-phosphate medium induced calcium deposition, apoptosis, and expression of osteogenic marker genes, producing a phenotype resembling valve calcification in vivo. These phenotypic changes were attenuated by the histone acetyltransferase inhibitor C646. C646 treatment increased the levels of class I histone deacetylase members and decreased the acetylation of histones 3 and 4 induced by the high-calcium/high-phosphate treatment. Conversely, the histone deacetylase inhibitor suberoylanilide hydroxamic acid promoted valve interstitial cell calcification. In a mouse model of aortic valve calcification induced by adenine and vitamin D treatment, the levels of acetylated histones 3 and 4 were increased in the calcified aortic valves. Treatment of the models with C646 attenuated aortic valve calcification by restoring the levels of acetylated histones 3 and 4. These observations suggest that increased acetylation of histones 3 and 4 is part of the pathogenesis of aortic valve calcification associated with calcium and phosphate metabolic disorders. Targeting acetylated histones 3 and 4 may be a potential therapy for inoperable aortic valve calcification in chronic kidney disease patients.

De novo Cardiac Valve Calcification after Hemodialysis in End-Stage Renal Disease Patients Predicts Future Cardiovascular Events: A Longitudinal Cohort Study

BACKGROUND

Cardiac valve calcification (CVC) in maintenance hemodialysis patients is associated with adverse cardiovascular outcomes. However, whether de novo CVC in incident hemodialysis patients predicts future cardiovascular events is unknown.

METHODS

This study included 174 patients newly receiving hemodialysis without CVC as reflected by echocardiography between January 2005 and December 2014. De novo CVC was determined with echocardiography once every 6 months until December 2016.

RESULTS

The median follow-up was 66 months (range, 19-141). De novo CVC developed in 80 out of 174 (45.98%) subjects: 58 developed aortic valve calcification (AVC) alone, 42 developed mitral valve calcification (MVC) alone, and 20 developed both AVC and MVC. The median time from baseline to de novo CVC was 46 months (range, 3-120) for AVC and 50 months (range, 13-127) for MVC. Patients who developed CVC had a higher major adverse cardiovascular events (MACE) rate than those who did not (AVC: 30/58 [51.72%] vs. 23/116 [19.83%]; MVC: 25/42 [59.52%] vs. 28/132 [21.21%]). Multivariate time-dependent Cox regression showed an association between MACE with both de novo AVC and MVC (AVC: hazard ratio [HR] 3.2, 95% confidence interval [CI] 1.55-6.63; MVC: HR 5.95, 95% CI 2.90-12.20).

CONCLUSIONS

De novo CVC is an independent risk factor for MACE in hemodialysis patients, and regular CVC screening among hemodialysis patients without preexisting CVC may be helpful to identify patients at increased risk of adverse cardiovascular outcomes.

Prevalence and Prognostic Implications of Mitral and Aortic Valve Calcium in Patients With Chronic Kidney Disease

Calcium in the cardiac valves can be observed in patients with severe chronic kidney disease (CKD). However, the prevalence and prognostic implications of left-sided cardiac valve calcium in patients with stage 2 and 3 CKD (estimated glomerular filtration rate (eGFR) of 60 to 89 and 30 to 59 ml/min/1.73 m² respectively) is unknown. The present study investigates the prevalence of mitral and aortic valve calcium in patients with stage 2 and 3 CKD and evaluates its association with all-cause mortality. In patients with stage 2 and 3 CKD who underwent clinically indicated coronary computed tomography angiography, the presence of mitral and/or aortic valve calcium was assessed. Patients were divided into 2 groups according to the presence of mitral and/or aortic valve calcium on coronary computed tomography angiography. Patients were followed for the occurrence of all-cause mortality (primary end point). Of 204 stage 2 and 3 CKD patients (54% men, mean age 60 ± 10 years), 66 (32%) patients had mitral and/or aortic valve calcium. During a median follow-up of 6 years (IQR; 2, 9 years), 29 (14%) patients died. Patients with mitral and/or aortic valve calcium showed significantly higher mortality rates compared with patients without left-sided valve calcium (log-rank p = 0.009). Mitral valve calcium was independently associated with increased risk of all-cause mortality, whereas aortic valve calcium was not. In conclusion, the prevalence of left-sided valve calcium in patients with stage 2 and 3 CKD is high. Mitral valve calcium was independently associated with increased risk of all-cause mortality, whereas aortic valve calcium was not.

Heart Valve Disease Predict Mortality in Hemodialysis Patients: A Single Center Experience

Our aim is to investigate the clinical and laboratory findings affecting the mortality of the patients in 3 years follow-up who underwent hemodialysis at our center. In this retrospective, observational cohort study, 432 patients who underwent hemodialysis at our center for at least 5 months were included. The first recorded data and subsequent clinical findings of patients who died and survived were compared. Two hundred and ninety patients survived, 142 patients died. The mean age of the patients who died was higher (63.4 ± 12.3 years, vs. 52 ± 16.1 years, P = 0.0001), 60.5% of them had coronary artery disease (P = 0.0001), 93.7% of them had a heart valve disease. Duration of hemodialysis (survived 57 [21-260] months; died 44 [5-183] months, P = 0.000) was lower in patients who died. Serum potassium level before dialysis (5.1 ± 0.6; 4.9 ± 0.7 mEq/L, P = 0.030), parathyroid hormone (435 [4-3054]; 304 [1-3145] pg/mL, P = 0.0001), albumin (3.9 ± 0.4; 3.8 ± 0.4 mg/dL, P = 0.0001) and Kt/V (1.48 ± 0.3; 1.40 ± 0.3, P = 0.019) levels were lower, C-reactive protein (5[1-208]; 8.7[2-256] mg/L, P = 0.000) levels were higher in patients who died. Logistic regression analysis showed age (OR = 1.1), coronary artery disease (OR = 1.7) and more than one heart valve disease (OR = 2.4) are independent risk factors for mortality. Potassium level before dialysis (OR = 0.60), parathyroid hormone (OR = 0.99), and higher Kt/V (OR = 0.28) were found to be an advantage for survival. Age, coronary artery disease and especially pathology in more than one heart valve are risk factors for mortality. Heart valve problems might develop because of malnutrition and inflammation caused by the chronic renal failure.

Cardiac valve calcification and risk of cardiovascular or all-cause mortality in dialysis patients: a meta-analysis

BACKGROUND

Vascular calcification is a risk factor for the pathogenesis of cardiovascular disease and mortality in dialysis patients. Nevertheless, the association between cardiac valve calcification (CVC) and the outcome of dialysis is still illusive. The purpose of this meta-analysis is to evaluate the association between theCVC and cardiovascular or all-cause mortality in dialysis patients.

METHODS

Literatures involving the baseline CVC and cardiovascular or all-cause mortality in dialysis patients were searchedfrom the PubMed, Embase, as well as two Chinese databases (i.e. Wanfang and CNKI databases). Articles published before November 2016were eligible to the study.

RESULTS

Ten studies involving 2686 participants were included. CVC was correlated with increased risk of cardiovascular mortality (hazard risk [HR]: 2.81; 95% confidence intervals [CI]: 1.92-4.10) and all-cause mortality (HR: 1.73; 95% CI: 1.42-2.11). Subgroup analysis showed an excess risk of all-cause mortality (HR: 1.35; 95% CI: 1.02-1.79) among patients with one CVC, and increased risk of all-cause mortality in patients with two CVCs (HR 2.15; 95% CI 1.57-2.94).

CONCLUSIONS

CVC is correlated with higher cardiovascular and all-cause mortality risk in dialysis patients. Regular follow-up monitoring of CVC may be helpful for risk stratification of patients underwent dialysis.

Hypervolemia, hypoalbuminemia and mitral calcification as markers of cardiovascular risk in peritoneal dialysis patients

INTRODUCTION

Mortality in patients with end-stage renal disease is higher than in the general population. This is linked to traditional and non-traditional cardiovascular (CV) risk factors, as well as with risk factors associated with end-stage renal disease itself. The aim of this study is to identify CV risk markers in patients beginning peritoneal dialysis (PD) and their association with CV events and CV mortality.

METHODS

This was a retrospective cohort study of 112 incident PD patients, in which demographic, clinical and laboratory parameters, valvular calcifications, types of PD solutions, hospitalizations, CV events and death were analyzed. Occurrence of CV events or death due to a CV event after PD initiation was defined as the primary endpoint. The use of icodextrin solution was taken as a marker of hypervolemia.

RESULTS

Mean age was 53.7±16.1 years. Patients were treated with PD for 29.3±17.4 months. Eighteen patients (16.1%) had valvular calcifications at baseline, 15 patients (13.4%) had major CV events and 11 patients (9.8%) died from CV-related causes. Cox proportional hazards analysis of CV events or CV-related mortality revealed that mitral calcification, use of icodextrin solution and low albumin were independent predictors of CV events or mortality.

CONCLUSIONS

Traditional CV risk factors appear to have little impact on CV complications in PD patients. Nevertheless, hypervolemia, hypoalbuminemia and mitral calcifications were independent predictors of CV events or mortality in this group of patients.

Predictive Value of Aortic Valve Calcification for Periprocedural Myocardial Injury in Patients Undergoing Percutaneous Coronary Intervention

AIMS

Previous studies have shown that aortic valve calcification (AVC) was associated with cardiovascular events and mortality. On the other hand, periprocedural myocardial injury (PMI) in percutaneous coronary intervention (PCI) is a well-known predictor of subsequent mortality and poor clinical outcomes. The purpose of the study was to assess the hypothesis that the presence of AVC could predict PMI in PCI.

METHODS

This study included 370 patients treated with PCI for stable angina pectoris. AVC was defined as bright echoes ＞1 mm on one or more cusps of the aortic valve on ultrasound cardiography (UCG). PMI was defined as an increase in high-sensitivity troponin T level of ＞5 times the upper normal limit (＞0.070 ng/ml) at 24 hours after PCI.

RESULTS

AVC was detected in 45.9% of the patients (n=170). The incidence of PMI was significantly higher in the patients with AVC than in those without AVC (43.5% vs 21.0%, p＜0.001). The presence of AVC independently predicted PMI after adjusting for other significant variables (odds ratio 2.26, 95% confidence interval 1.37-3.74, p=0.002). Other predictors were male sex, age, estimated glomerular filtration rate, and total stent length. Furthermore to predict PMI, adding AVC to the established risk factors significantly improved the area under the receiver operating characteristic curves, from 0.68 to 0.72, of the PMI prediction model (p=0.025).

CONCLUSION

The presence of AVC detected in UCG could predict the incidence of PMI.

The Association of Ankle Brachial Index, Protein-Energy Wasting, and Inflammation Status with Cardiovascular Mortality in Patients on Chronic Hemodialysis

Protein-energy wasting (PEW) is highly prevalent in hemodialysis (HD) patients. We investigated the association of abnormal ankle brachial index (ABI), PEW, and chronic inflammation status with clinical prognosis in HD patients. A total of 973 HD patients were enrolled and were followed-up for 8 years. As a marker of the PEW, geriatric nutritional risk index (GNRI) was used. Cut-off levels were 91.2 for GNRI defined from previous studies and 1.9 mg/L for C-reactive protein (CRP) as median value, respectively. Abnormal ABI was seen in 332 (34.1%) patients. Declined GNRI and elevated CRP levels were independently associated with abnormal ABI (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.96–0.99, p = 0.0009 and OR 1.40, 95% CI 1.07–1.83, p = 0.013, respectively). GNRI levels were also independently correlated with CRP levels (β = −0.126, p < 0.0001). During follow-up period, 283 (29.1%) patients died, including 123 (12.6%) due to cardiovascular disease (CVD). Abnormal ABI (adjusted hazard ratio (HR) 1.62, 95% CI 1.13–2.32, p = 0.0096), GNRI < 91.2 (adjusted HR 1.57, 95% CI 1.06–2.33, p = 0.023) and CRP > 1.9 mg/L (adjusted HR 1.89, 95% CI 1.31–2.77, p = 0.0007) independently predicted mortality due to CVD, respectively. In conclusion, abnormal ABI, GNRI, and CRP levels were closely associated with each other, and the combination of these variables increase their predictive values for the risk of mortality due to CVD and all-cause mortality in HD patients.

Imaging for Vascular Calcification

Chronic decline in renal function is accompanied by deterioration of bone structure and function and progressive calcification of the vascular system. Both disease states have been linked with increased morbidity and mortality in chronic kidney disease. The severe alterations of mineral metabolism inherent with loss of renal function have an impact on vascular calcification development and progression, and several investigators have focused on ways to reduce their impact on vascular health. Imaging has contributed an important role in the assessment of vascular calcification, and the impact of various interventions aimed at curbing their progression.

Coronary artery calcification in CKD-5D patients is tied to adverse cardiac function and increased mortality

Background: Coronary artery calcification (CAC) is common in patients with chronic kidney disease on hemodialysis (CKD-5D) and is an important predictor of mortality. However, cardiac functional links between CAC and mortality have not been well established. This study tested the hypothesis that CAC increases mortality by adversely affecting cardiac function. Methods: Patients were recruited from 37 regional dialysis centers. 2-D and Doppler echocardiographic analyses were performed, and CAC was measured using 64-slice computed tomography. Relationships between CAC and echocardiographic measures of left ventricular (LV) function were analyzed. Survival was assessed with median follow-up of 37 months. Results: There were 157 patients: 59% male, 46% Caucasian, 48% diabetic. Median age was 55 years, and median duration of CKD-5D was 45 months. Agatston CAC scores > 100 were found in 69% of patients, with 51% having a score > 400. CAC was associated with measures of LV systolic and diastolic function (global longitudinal strain (GLS; rho = 0.270, p = 0.004)), peak LV systolic velocity (rho = –0.259, p = 0.004), and estimate of LV filling pressure (E:E’; rho = 0.286, p = 0.001). Multivariate regression confirmed these relationships after adjustment for age, gender, LV ejection fraction, and coronary artery disease. Valvular calcification varied linearly with CAC (p < 0.05). Both LV diastolic and systolic functional measures were significant predictors of mortality, the strongest of which was LV diastolic dysfunction. Conclusions: These findings show a link between CAC, cardiac function, and mortality in CKD-5D. LV diastolic function (E:E’), peak LV systolic velocity, and GLS are independent predictors of mortality. Valvular calcification may be an important marker of CAC in CKD-5D. These effects on cardiac function likely explain the high mortality with CKD-5D and describe a potentially-valuable role for echocardiography in the routine management of these patients.

Incidence of sudden cardiac death in adults with end-stage renal disease: a systematic review and meta-analysis

BACKGROUND

Although sudden cardiac death (SCD) is recognized as a distinct cause of death in patients with end stage renal disease (ESRD), its incidence has not been well summarized.

METHODS

We performed a systematic review and meta-analysis of the literature based on a protocol developed a priori. We searched MEDLINE and EMBASE (inception to March 2015) for randomized controlled trials and cohort studies reporting the incidence of SCD in adult patients with ESRD on hemodialysis or peritoneal dialysis. We collected data on number of SCD as well as the definition of SCD for each individual study. A random-effects model was used to summarize the incidence of SCD. We conducted subgroup analyses to explore sources of heterogeneity.

RESULTS

Forty two studies (n = 80,382 patients) were included in the meta-analysis. The incidence of SCD among adults with ESRD ranged from 0.4 to 10.04 deaths per 100 person-years. The definitions and assessment of SCD varied across the included studies. There was evidence of significant heterogeneity (I(2) = 98; p < 0.001), which was not explained by subgroup analyses stratified by mean age, proportion of hypertensive or diabetic patients, follow-up time, study size, or type of cohort studied.

CONCLUSION

Current estimates of the incidence of SCD among adults with ESRD vary widely. There is a need for further studies to more accurately estimate the incidence of SCD in patients with ESRD.

Apoprotein B/Apoprotein A-1 Ratio and Mortality among Prevalent Dialysis Patients

BACKGROUND AND OBJECTIVES

In dialysis patients, the associations between apoprotein profile and all-cause or cardiovascular disease (CVD)-related mortality are not well known. We, therefore, investigated whether apoprotein levels are associated with these events.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We undertook a prospective observational cohort study of prevalent hemodialysis patients aged ≥18 years (n=1081), who were followed for 4 years (2011-2014). Outcomes were all-cause and CVD-related mortality. Predictors used were baseline apoprotein levels, particularly the apoprotein B (apo B)/ apoprotein A-1 (apo A-1) ratio. A Cox regression analysis was used to calculate the hazard ratios (HRs) for mortality. Apo A-1, apo B, and apo B/ apo A-1 ratio were analyzed with adjustments in three models: model 1, basic adjustment for age and sex; model 2, basic adjustments plus dialysis conditions (dialysis vintage, mean predialysis systolic blood pressure, dry weight, and mean intradialytic weight gain); and model 3, model 2 plus metabolic and inflammatory conditions (basal kidney disease, serum albumin, C-reactive protein level, and statin use).

RESULTS

Of the 1081 patients included in the study, 203 deaths were recorded, 92 of which were related to CVD. The apo B/ apo A-1 ratio was significantly associated with all-cause and CVD-related mortality when analyzed by 1-SD increments or quartile IV versus I in all models. In model 3, HRs and 95% confidence intervals (95% CIs) for 1-SD increments of apo B/ apo A-1 ratio for all-cause mortality or CVD-related mortality were: HR, 1.16 (95% CI, 1.00 to 1.35), or HR, 1.38 (95% CI, 1.11 to 1.71), respectively, and for quartile IV versus I: HR, 1.65 (95% CI, 1.05 to 2.57), or HR, 2.56 (95% CI, 1.21 to 5.40), respectively. Apo A-1 was significantly associated with both mortalities in models 1 and 2. However, apo B was only significantly associated with CVD-related mortality in model 3.

CONCLUSIONS

Apoprotein measurement, especially the apo B/ apo A-1 ratio, was significantly associated with all-cause and CVD-related mortality in prevalent dialysis patients.

Fibroblast growth factor 23 and parathyroid hormone predict extent of aortic valve calcifications in patients with mild to moderate chronic kidney disease

BACKGROUND

Cardiac valve calcifications are present in dialysis patients and regarded as dependent on a deranged mineral metabolism. Few data are available for patients with chronic kidney disease (CKD) not on dialysis. This study evaluates the potential association between the extent of cardiac valve calcification and levels of intact parathyroid hormone (i-PTH), phosphorus, calcium, 25-OH vitamin D, fibroblast growth factor 23 (FGF-23), Klotho and C-reactive protein (CRP) simultaneously measured in patients with mild to moderate CKD.

METHODS

Consecutive non-hospitalized patients referring to five nephrology units were evaluated. Inclusion criteria were age >18 years, CKD Stages 3-4, and the presence of aortic and/or mitral valve calcification assessed by echocardiography as routinely clinical evaluation. Patients underwent clinical examination and routine biochemistry. Baseline i-PTH, phosphorus, calcium, 25-OH vitamin D, FGF-23, Klotho and CRP were simultaneously ascertained.

RESULTS

Extent of aortic valve calcification (n = 100 patients) was moderate in 68 patients and mild in the remaining patients. Mitral valve calcification (n = 96 patients) score was 1, 2 and 3 in 61, 34 and 1 patients, respectively. In univariate analysis, no association was found between extent of mitral valve calcification and markers of mineral metabolism and CRP; aortic valve extent of calcification was positively associated with i-PTH (r(2) = 0.212; P = 0.03) and FGF-23 (r(2) = 0.272; P = 0.01), and negatively with Klotho (r(2) = -0.208; P = 0.04). In multivariable analysis, extent of aortic valve calcification was associated with FGF-23 (P = 0.01) and PTH (P = 0.01) levels.

CONCLUSIONS

Extent of aortic valve calcification is associated to FGF-23 and PTH in naïve CKD patients with mild to moderate CKD. Further studies should examine whether FGF-23 assay should be included in routine clinical evaluation of CKD as part of cardiovascular risk stratification.

Valvular calcifications at the start of dialysis predict the onset of cardiovascular events in the course of follow-up

OBJECTIVE

To analyse the presence of VC at the start of dialysis and its relationship with events and/or death from cardiovascular causes in the course of follow-up.

METHODS

In the study, we included patients who started dialysis between November 2003 and September 2007. In the first month of treatment, we assessed the presence of VC by Doppler echocardiography, along with demographic factors and risk factors for cardiovascular disease, coronary artery disease, stroke, atrial fibrillation (AF), and cardiac dimensional and functional electrocardiographic and echocardiographic parameters. The biochemistry values assessed were: haemoglobin, calcium/phosphorous/iPTH metabolism, cholesterol and fractions, triglycerides, troponin I, albumin, CRP and glycosylated haemoglobin. We analysed the association between VC and the presence of myocardial infarction (MI), stroke and/or death from cardiovascular causes up to transplantation, death or the end of the study (December 2012).

RESULTS

Of 256 enrolled patients (83% haemodialysis, 17% peritoneal dialysis), 128 (50%) had VC (mitral: 39, aortic: 20, both: 69). In the multivariate analysis, VC was associated with older age (OR: 1.110; 95% CI: 1.073-1.148; p = 0.000) and lower albumin levels (OR: 0.29; 95% CI: 0.14-0.61; p = 0.001). In a follow-up lasting 42.1 ± 30.2 months (898.1 patient-years), 68 patients suffered MI, stroke and/or died from cardiovascular causes. In the Cox regression analysis, older age (HR: 1.028; 95% CI: 1.002-1.055; p = 0.037), coronary artery disease and/or stroke (HR: 1.979; 95% CI: 1.111-3.527; p = 0.021), AF (HR: 2.474; 95% CI: 1.331-4.602; p = 0.004), and the presence of VC at the start of dialysis (HR: 1.996; 95% CI: 1.077-3.700; p = 0.028) were the predictor variables for the occurrence of the analysed events.

CONCLUSIONS

The prevalence of VC at the start of dialysis is high and its presence predicts the occurrence of events and/or cardiovascular death in the course of follow-up.

The combination of preoperative serum C-reactive protein and carcinoembryonic antigen is a useful prognostic factor in patients with esophageal squamous cell carcinoma: a combined ROC analysis

Background

The prognostic value of inflammatory index in esophageal cancer (EC) has not been established. In the present study, therefore, we initially evaluated a novel prognostic system, named the COCC (COmbination of C-reactive protein [CRP] and carcinoembryonic antigen [CEA]), for making a prognosis in patients with esophageal squamous cell carcinoma (ESCC).

Methods

A total of 327 patients with ESCC between January 2006 and December 2008 were included in this retrospective study. The COCC was calculated by combined CRP and CEA according to the logistic equation. The Kaplan–Meier method was used to calculate the cancer-specific survival (CSS), and the difference was assessed by the log-rank test. Cox regression analyses were performed to evaluate the prognostic factors.

Results

In our study, COCC was defined as CRP +0.71 CEA according to the logistic equation. Receiver operating characteristic curves for CSS prediction were plotted to verify the optimum cutoff points for CRP, CEA, and COCC, which were 9.8 mg/L, 4.2 ng/mL, and 8.0, respectively. Patients with COCC ≤8.0 had a significantly better CSS than patients with COCC >8.0 (53.1% vs 15.3%, P<0.001). Multivariate analysis revealed that COCC was an independent prognostic factor in patients with ESCC (P=0.006). In addition, the area under the curve (AUC) was 0.722 for COCC, 0.645 for CRP, and 0.618 for CEA, indicating that COCC was superior to CRP or CEA for CSS prediction.

Conclusion

The COCC is an independent prognostic factor in patients with ESCC. We conclude that COCC was superior to CRP or CEA as a more precise prognostic factor in patients with ESCC.

Association of fatty liver disease with nonfatal cardiovascular events in patients undergoing maintenance hemodialysis

BACKGROUND/AIMS

The prevalence of cardiovascular (CV) disease in patients undergoing maintenance hemodialysis (HD) is reportedly higher than that in healthy individuals. In the present study, we aimed to investigate whether ultrasonographically documented fatty liver disease (FLD) is an independent risk factor for nonfatal CV events in patients undergoing HD.

METHODS

A retrospective cohort study was conducted in a medical center in southern Taiwan. The medical records of 490 patients undergoing HD who were enrolled between July 1998 and October 2012 were screened. Finally, 278 patients who had undergone hepatic ultrasonography and had available data were recruited in the present study. The patients included 130 men and 148 women; their mean age was 59.9 years. The primary endpoint was nonfatal CV events in the observation period. The comparable data included epidemiological, hematological, and biochemical profiles. A time-dependent statistical method was used to analyze the associated factors.

RESULTS

The prevalence of nonfatal CV events was significantly increased in the patients with FLD compared with those without FLD (CV events: 32 vs. 18%, respectively; p = 0.008). After adjusting for associated risk factors (sex, age, body mass index, smoking, diabetes, hypertension, dyslipidemia, and Kt/V), multivariate analyses identified FLD (CV events: hazard ratio 2.84, 95% confidence interval 1.52-5.28, p = 0.001), advanced age, and diabetes to be independently associated with nonfatal CV events.

CONCLUSION

The study suggests that FLD was an independent risk factor for nonfatal CV events in patients undergoing maintenance HD.

Extraosseous calcification in end-stage renal disease: from visceral organs to vasculature

In earlier days, periarticular accumulations of calcium phosphate causing tumor-like depositions were considered the result of passive precipitation and referred to as metastatic calcifications. From sophisticated computer tomographic studies and growing insight, we have learned that calcifications in the cardiovascular system are far more threatening and in fact one of the most important sequela of end-stage renal disease. The histologic characteristic of uremia-related calcification is arteriosclerosis of the media. In addition, there is atherosclerosis of the intima, due to the high prevalence of classic cardiovascular risk factors in renal disease. The two vascular features can frequently exist at different sites in the vasculature. Novel diagnostic techniques are helping to elucidate the pathogenetic mechanisms of active conversion of vascular smooth muscle cells to osteochondritic cells. Through this process, extensive calcification of the central and peripheral vasculature ensues, influenced by different promotors and inhibitors. Calciphylaxis is a special form of extraosseous calcification leading to skin necrosis. The factors that trigger the development of calciphylaxis are not completely understood, but this syndrome shares part of the pathophysiologic basis of extraosseous calcification in general. However, the therapeutic approach must be prompt and aggressive, because of the poor prognosis. Frequently, a fatal outcome cannot be avoided in calciphylaxis.

Aortic valve calcification in chronic kidney disease

Several clinical studies reported an increased prevalence and accelerated progression of aortic valve calcification among patients with end-stage renal disease when compared with subjects with normal kidney function. Recently, mechanisms of calcific valve degeneration have been further elucidated and many of the pathways involved could be amplified in patients with decreased renal function. In particular, calcium-phosphate balance, MGP metabolism, OPG/RANK/RANKL triad, fetuin-A mineral complexes and FGF-23/Klotho axis have been shown to be impaired among patients with advanced chronic kidney disease and could play a role during vascular/valve calcification. The scope of the present review is to summarize the clinical data and the pathophysiological mechanisms potentially involved in the link between renal function decline and the progression of aortic valve disease.