Impact of high coronary artery calcification score (CACS) on survival in patients on chronic hemodialysis

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

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

Randomized Controlled Clinical Trial of the Effect of Treatment with Vitamin K2 on Vascular Calcification in Hemodialysis Patients (Trevasc-HDK)

Introduction

Vitamin K deficiency among patients on hemodialysis (HD) affects the function of matrix GLA protein (MGP), a potent vitamin K-dependent inhibitor of vascular calcification (VC).

Methods

We conducted a single-center randomized controlled trial (RCT) on maintenance HD patients to examine if vitamin K2 supplementation can reduce progression of coronary artery calcification (CAC) over an 18-month study period. Patients were randomized to vitamin K2 group receiving menaquinone-7360 μg 3 times/wk or control group. The primary outcome was CAC scores at the end of the study period. The secondary outcomes were aortic valve calcification (AVC), carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx), dephosphorylated undercarboxylated MGP (dp-ucMGP) levels, major adverse cardiac events (MACE), and vascular access events.

Results

Of the 178 patients randomized, follow-up was completed for 138 patients. The CAC scores between the 2 groups were not statistically different at the end of 18 months (relative mean difference [RMD] 0.85, 95% CI 0.55-1.31). The secondary outcomes did not differ significantly in AVC (RMD 0.82, 95% CI 0.34-1.98), cfPWV (absolute mean difference [AMD] 0.55, 95% CI -0.50 to 1.60), and AIx (AMD 0.13, 95% CI -3.55 to 3.80). Supplementation with vitamin K2 did reduce dp-ucMGP levels (AMD -86, 95% CI -854 to -117). The composite outcome of MACE and mortality was not statistically different between the 2 groups (Hazard ratio = 0.98, 95% CI 0.50-1.94).

Conclusion

Our study did not demonstrate a beneficial effect of vitamin K2 in reducing progression of VC in this population at the studied dose and duration.

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

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

Low bone mineral density is associated with coronary arterial calcification progression and incident cardiovascular events in patients with chronic kidney disease

Background

Although it is well known that low bone mineral density (BMD) is associated with an increased risk of cardiovascular disease (CVD) and mortality in the general population, the prognostic role of bone mineral density (BMD) has not been established in the chronic kidney disease (CKD) population. Therefore we aimed to evaluate the association between BMD and the risk of CVD and cardiovascular mortality in patients with predialysis CKD.

Methods

This prospective cohort study was conducted with 1957 patients with predialysis CKD Stages 1–5. BMD was measured using dual-energy X-ray absorptiometry and coronary arterial calcification (CAC) scores were evaluated using coronary computed tomography. The primary outcome was a major adverse cardiovascular event (MACE).

Results

When patients were classified based on total hip BMD T-score tertiles stratified by sex, the lowest BMD tertile was significantly associated with an increased risk of MACE {hazard ratio 2.16 [95% confidence interval (CI) 1.25–3.74]; P = 0.006}. This association was also shown with BMD at the femur neck but not with BMD at lumbar spine. In the subgroup of 977 patients with follow-up CACs at their fourth year, 97 (9.9%) showed accelerated CAC progression (>50/year), and BMD was inversely associated with accelerated CAC progression even after adjusting for the baseline CAC score [odds ratio 0.75 (95% CI 0.58–0.99); P = 0.039]. In addition, baseline CAC was associated with an increased risk of MACEs after adjusting for total hip T-score.

Conclusions

Low BMD was significantly associated with CAC progression and MACEs in patients with predialysis CKD.

Choosing between anatomy and function is not always evident for the heart of end-stage renal disease patients. How low can we go?

Patients with chronic kidney disease (CKD) are at a very high risk of adverse cardiovascular events. In CKD patients, vascular calcification is more prevalent, appears at an earlier age, and is more severe than in the general population. CKD physiology rather than the effects of dialysis is the primary driver of microvascular disease in these patients. Considering the significant morbidity and mortality attributable to cardiovascular disease in the CKD population, risk stratification remains an important challenge. Topics such as function vs anatomy to properly risk stratify these patients, as well as future perspectives on non-invasive techniques, will be addressed.

Epicardial fat tissue, coronary arterial calcification and mortality in patients with advanced chronic kidney disease and hemodialysis

INTRODUCTION AND OBJECTIVES

Epicardial and mediastinal adipose tissue (EAT, MAT) are linked to metabolic syndrome and coronary artery disease. Patients with chronic kidney disease (CKD) have thicker EAT. We assessed if EAT and MAT could be associated with increased mortality and cardiovascular events in patients with advanced CKD and haemodialysis therapy.

METHODS

A post-hoc study was performed. We analyzed a prospective series of 104 cases. EAT thickness was quantified by a multislice synchronized computed tomography (MSCT).

RESULTS

The follow-up period was 112.68 (109.94-115.42) months. The optimal cut-off point of EAT for prediction of total mortality was 11.45 mm (92.86% and 43.75%). EAT thickness was associated with serum albumin levels, serum triglyceride levels, phosphorus and calcium phosphate product. The EAT was greater in haemodialysis patients compared to those with advanced CKD (P < .001). Patients with diabetes mellitus had greater EAT and MAT thickness (P = .018). At the end of follow up, the survival average time of patients with EAT thickness <11.45 mm was 97.48 months vs. 76.65 months for thickness > 11.45 mm (P = .007).

CONCLUSIONS

A higher EAT and MAT thickness was associated with increased mortality. Furthermore, EAT was associated with lower free survival time to fatal and non-fatal cardiovascular events. The measurement of EAT and MAT by MSCT could be a prognostic tool to predict cardiovascular events and mortality risk in advanced CKD patients.

Sparing effect of peritoneal dialysis vs hemodialysis on BMD changes and its impact on mortality

INTRODUCTION

Bone loss in end stage renal disease (ESRD) patients associates with fractures, vascular calcification, cardiovascular disease (CVD) and increased mortality. We investigated factors associated with changes of bone mineral density (ΔBMD) during the initial year on dialysis therapy and associations of ΔBMD with subsequent mortality in ESRD patients initiating dialysis.

MATERIALS AND METHODS

In 242 ESRD patients (median age 55 years, 61% men) starting dialysis with peritoneal dialysis (PD; n = 138) or hemodialysis (HD; n = 104), whole-body dual-energy X-ray absorptiometry (DXA), body composition, nutritional status and circulating biomarkers were assessed at baseline and 1 year after dialysis start. We used multivariate linear regression analysis to determine factors associated with ΔBMD, and fine and gray competing risk analysis to determine associations of ΔBMD with subsequent mortality risk.

RESULTS

BMD decreased significantly in HD patients (significant reductions of BMD_total and BMD_{leg, trunk, rib, pelvis and spine}) but not in PD patients. HD compared to PD therapy associated with negative changes in BMD_{total (β=- 0.15)}, BMD_{head (β=- 0.14)}, BMD_{leg (β=- 0.18)} and BMD_{trunk (β=- 0.16)}. Better preservation of BMD associated with significantly lower all-cause mortality for ΔBMD_total (sub-hazard ratio, sHR, 0.91), ΔBMD_head (sHR 0.91) and ΔBMD_leg (sHR 0.92), while only ΔBMD_head (sHR 0.92) had a beneficial effect on CVD-mortality.

CONCLUSIONS

PD had beneficial effect compared with HD on BMD changes during first year of dialysis therapy. Better preservation of BMD, especially in bone sites rich in cortical bone, associated with lower subsequent mortality. BMD in cortical bone may have stronger association with clinical outcome than BMD in trabecular bone.

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.

Osteocalcin and Abdominal Aortic Calcification in Hemodialysis Patients: An Observational Cross-Sectional Study

OBJECTIVES

To investigate the serum level of osteocalcin (OC), also known as bone Gla protein, in maintenance hemodialysis (MHD) patients and its correlation with abdominal aortic calcification (AAC).

METHODS

From July 2017 to February 2020, we enrolled 108 adult MHD patients. Routine fasting blood laboratory tests were performed before the start of the second hemodialysis in a week. Abdominal aortic calcification score (AACs) was assessed within 1 month. Pearson correlation and Logistic regression were used to analyze the data.

RESULTS

The OC level was 231.56 (25.92,361.33) ng/ml, elevating significantly in this group of MHD patients. It had a positive correlation with serum phosphorus (r = 0.511, P = 0.001), intact parathyroid hormone(iPTH) (r = 0.594, P = 0.0001), fibroblast growth factor 23(FGF23) (r = 0.485, P = 0.003) and a negative correlation with age(r = -0.356, P = 0.039). Based on the AACs, patients were divided into two groups. Serum OC level were higher in patients with AACs≥5 (p=0.032). A multiple logistics regression analysis revealed that age (odds ratio [OR]1.14, P=0.005) and OC(OR=1.10, P=0.008)were risk factors for high AACs(≥5).

CONCLUSION

The study implicated that OC elevated significantly in this group of MHD patients.OC is positively correlated with phosphorus, iPTH, FGF23, and a negative correlation with age. OC was a risk factor for vascular calcification in this study, but this study did not classify osteocalcin as c-OC and unOC. Whether unOC is associated more directly with vascular calcification requires further study.

Inverse J-shaped relation between coronary arterial calcium density and mortality in advanced chronic kidney disease

BACKGROUND

The coronary artery calcium (CAC) score from cardiac computed tomography (CT) is a composite of CAC volume and CAC density. In the general population, CAC volume is positively and CAC density inversely associated with cardiovascular disease (CVD) events, implying that decreased CAC density reflects atherosclerotic plaque instability. We analysed associations of CAC indices with mortality risk in patients with end-stage renal disease [chronic kidney disease Stage 5 (CKD5)].

METHODS

In 296 CKD5 patients undergoing cardiac CT (median age 55 years, 67% male, 19% diabetes, 133 dialysed), the Framingham risk score (FRS), presence of CVD and protein-energy wasting (PEW; subjective global assessment) and high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) were determined at baseline. During follow-up for a median of 35 months, 51 patients died and 75 patients underwent renal transplantation. All-cause mortality risk was analysed with competing-risk regression models. Vascular calcification was analysed in biopsies of the arteria epigastrica inferior in 111 patients.

RESULTS

Patients in the middle tertile of CAC density had the highest CAC score, CAC volume, age, CVD, PEW, FRS, hsCRP and IL-6. In competing risk analysis, the middle {subhazard ratio [sHR] 10.7 [95% confidence interval (CI) 2.0-57.3]} and high [sHR 8.9 (95% CI 1.5-51.8)] tertiles of CAC density associated with increased mortality, independent of CAC volume. The high tertile of CAC volume, independent of CAC density, associated with increased mortality [sHR 8.9 (95% CI 1.5-51.8)]. Arterial media calcification was prominent and associated with CAC volume and CAC density.

CONCLUSIONS

In CKD5, mortality increased linearly with higher CAC score and CAC volume whereas for CAC density an inverse J-shaped pattern was observed, with the crude mortality rate being highest for the middle tertile of CAC density. CAC volume and CAC density were associated with the extent of arterial media calcification.

Treatment to reduce vascular calcification in hemodialysis patients using vitamin K (Trevasc-HDK): A study protocol for a randomized controlled trial

INTRODUCTION

End stage renal failure patients on hemodialysis have significant vascular calcification This is postulated to be related to sub-clinical vitamin K deficiency, which is prevalent in hemodialysis patients. Vitamin K deficiency result in the failure of the matrix GLA protein (MGP) to undergo carboxylation. MGP is a natural local inhibitor of vascular calcification and the lack of functional carboxylated MGP may contribute to increase vascular calcification. Vitamin K supplement should therefore correct this anomaly and decrease the rate or severity of vascular calcification in this population of patients on long-term maintenance hemodialysis. Our study seeks to evaluate the prevalence and the progression of vascular calcification in a cohort of maintenance hemodialysis patients. It will also evaluate the efficacy of vitamin K supplementation in reducing the progression of vascular calcification in this group of patients.

METHODS

This will be a single-center randomized, prospective and open-label interventional clinical trial of end stage renal failure patients on hemodialysis. We aim to recruit 200 patients. Eligible patients will be randomized to either the standard care arm or active treatment arm. Active treatment arm patients will receive standard care plus supplementation with oral vitamin K2 isoform 360 mcg 3 times weekly for a total duration of 18 months. Primary outcome measured will be absolute difference in coronary artery calcification score at 18-month between control and intervention arms. Secondary outcomes will be to compare absolute difference in aortic valve calcification, percentage of patients with regression of coronary artery calcification of at least 10%, absolute difference in aortic and systemic arterial stiffness, mortality from any cause and major adverse cardiovascular over the same period.

DISCUSSION

Evidence of successful regression or retardation of vascular calcification will support the conduct of larger and longer-term trials aimed at reducing cardiovascular disease mortality and major adverse cardiovascular events in this high-risk population using a safe and inexpensive strategy TRIAL REGISTRATION:: ClinicalTrials.gov NCT02870829. Registered on 17 August 2016 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02870829National University Hospital's Institutional Review Board (2015/01000).

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.

Bone mineral density and mortality in end-stage renal disease patients

Osteoporosis characterized by low bone mineral density (BMD) as assessed by dual-energy X-ray absorptiometry (DXA) is common among end-stage renal disease (ESRD) patients and associates with high fracture incidence and high all-cause mortality. This is because chronic kidney disease-mineral bone disorders (CKD-MBDs) promote not only bone disease (osteoporosis and renal dystrophy) but also vascular calcification and cardiovascular disease. The disturbed bone metabolism in ESRD leads to 'loss of cortical bone' with increased cortical porosity and thinning of cortical bone rather than to loss of trabecular bone. Low BMD, especially at cortical-rich bone sites, is closely linked to CKD-MBD, vascular calcification and poor cardiovascular outcomes. These effects appear to be largely mediated by shared mechanistic pathways via the 'bone-vascular axis' through which impaired bone status associates with changes in the vascular wall. Thus, bone is more than just the scaffolding that holds the body together and protects organs from external forces but is-in addition to its physical supportive function-also an active endocrine organ that interacts with the vasculature by paracrine and endocrine factors through pathways including Wnt signalling, osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/RANK ligand system and the Galectin-3/receptor of advanced glycation end products axis. The insight that osteogenesis and vascular calcification share many similarities-and the knowledge that vascular calcification is a cell-mediated active rather than a passive mineralization process-suggest that low BMD and vascular calcification ('vascular ossification') to a large extent represent two sides of the same coin. Here, we briefly review changes of BMD in ESRD as observed using different DXA methods (central and whole-body DXA) at different bone sites for BMD measurements, and summarize recent knowledge regarding the relationships between 'low BMD' and 'fracture incidence, vascular calcification and increased mortality' in ESRD patients, as well as potential 'molecular mechanisms' underlying these associations.

Quantified Vascular Calcification at the Dialysis Access Site: Correlations with the Coronary Artery Calcium Score and Survival Analysis of Access and Cardiovascular Outcomes

Vascular calcification is a major contributor to mortality in end-stage renal disease (ESRD) patients. In this study, we investigated whether there was a correlation between the coronary artery calcium score (CACS) and the vascular calcification score (VCS), and whether higher VCS increased the incidence of interventions and major adverse cardiac and cerebrovascular events (MACCE). ECG-gated CT, including vascular access and the coronary vessel, was taken. CACS and VCS were calculated by the Agatston method. A comparison of CACS and survival analysis according to VCS groups was performed. Using a cutoff of VCS = 500, 77 patients were divided into two groups. The vintage was significantly older in the higher VCS group. The median CACS was higher in the higher VCS group (21 [0, 171] vs. 552 [93, 2430], p < 0.001). The hazard ratio (HR) for interventions and MACCEs in the higher VCS group increased by 3.2 and 2.3, respectively. Additionally, a longer duration of hemodialysis and higher magnesium levels (>2.5 mg/dL) showed lower HRs for interventions (<1). We quantified VCS and found that it was associated with the CACS. Additionally, higher VCS increased the risk of access interventions and MACCE. VCS of the access site may be suggested as a biomarker to predict ESRD patients.

The Progression and Impact of Vascular Calcification in Peritoneal Dialysis Patients

Background

Progression of coronary artery calcification (CAC) has been described in hemodialysis patients, and severe CAC has been associated with the occurrence of cardiovascular events in this population. Little information is available regarding peritoneal patients.

Aim

To prospectively evaluate peritoneal dialysis patients in order to identify the variables associated with the rate of CAC progression, as well as to determine the impact that baseline CAC has on clinical outcomes over a 1-year follow-up period.

Methods

Using multislice coronary tomography, calcium scores were estimated at baseline and after 12 months in 49 peritoneal dialysis patients. Patients with and without CAC progression were compared with respect to clinical characteristics and biochemical variables, including lipid profile, parameters of mineral metabolism, and markers of inflammation. Cardiovascular events, hospitalizations, and all-cause mortality were recorded.

Results

At baseline, 29 patients (59%) presented CAC and a median calcium score of 234.7 (range 10.3 – 2351) Agatston units. Progression of CAC was observed in 13 patients (43%) who, in comparison with those presenting no CAC progression, were older, presented higher baseline calcium scores, and had higher mean glucose levels, lower mean high density lipoprotein cholesterol levels, and more months using low calcium peritoneal solution. We also observed a trend toward more often presenting with a history of hypertension, exhibiting more hyperphosphatemic and hyperglycemic events, and having lower albumin levels. In multiple logistic regression, only baseline calcium score was independently associated with progression of CAC. A shorter cardiovascular event-free time and a trend toward lower survival rates were observed in the group with CAC. Hospitalization event-free time did not differ between the groups.

Conclusion

Determining CAC provides important prognostic data in peritoneal dialysis patients. Baseline calcium score and disturbances in glucose, mineral, and lipid metabolism were indicative of higher risk of CAC progression in this population.

Bone mineral density at different sites and 5 years mortality in end-stage renal disease patients: A cohort study

BACKGROUND

Bone disease with osteoporosis and renal osteodystrophy is common in end stage renal disease (ESRD) patients and associates with cardiovascular disease (CVD) and increased morbimortality. We investigated associations of low bone mineral density (BMD) at various bone sites with five year all-cause and CVD mortality in ESRD patients.

METHODS

In a post hoc analysis of 426 ESRD patients (median age 56 years, 62% men) starting dialysis, BMD (whole-body dual-energy X-ray absorptiometry, DXA), body composition, nutritional status (subjective global assessment, SGA), handgrip strength (%HGS), Framingham CVD risk score (FRS) and biochemical biomarkers of nutrition and inflammation were assessed. We used the Fine and Gray competing risk regression analysis to assess survival analysis.

RESULTS

In multivariate logistic regression analysis, %HGS and intact parathyroid hormone associated with low tertile of: BMD_total, BMD_head and BMD_pelvis, after adjusting for FRS, SGA, %HGS, s-albumin, hsCRP, lean body mass index and year of recruitment. Patients with high FRS had low BMD_head (p<0.001). Low tertile of BMD_total (sHR, 1.53), BMD_head (sHR 1.54) and BMD_pelvis (sHR 1.60) associated with increased all-cause mortality whereas no such associations were found for the trabecular bone rich sites BMD arm, leg, trunk, rib or spine. Low tertile of BMD_total (sHR 1.94), BMD_head (sHR 1.68), BMD_leg (sHR 2.25) and BMD_pelvis (sHR 2.45) associated with increased CVD mortality whereas BMD at other sites did not associate with CVD mortality.

CONCLUSION

Low head and pelvis BMD, and low total BMD, as assessed by whole-body DXA, were independent predictors of increased risk of all-cause and CVD mortality. Cortical BMD appeared to have stronger association to survival in ESRD than trabecular BMD.

Gender-specific associations between coronary heart disease and other chronic diseases: cross-sectional evaluation of national survey data from adult residents of Germany

Background

Combinations of coronary heart disease (CHD) and other chronic conditions complicate clinical management and increase healthcare costs. The aim of this study was to evaluate gender-specific relationships between CHD and other comorbidities.

Methods

We analyzed data from the German Health Interview and Examination Survey (DEGS1), a national survey of 8152 adults aged 18–79 years. Female and male participants with self-reported CHD were compared for 23 chronic medical conditions. Regression models were applied to determine potential associations between CHD and these 23 conditions.

Results

The prevalence of CHD was 9% (547 participants): 34% (185) were female CHD participants and 66% (362) male. In women, CHD was associated with hypertension (OR = 3.28 (1.81–5.9)), lipid disorders (OR = 2.40 (1.50–3.83)), diabetes mellitus (OR = 2.08 (1.24–3.50)), kidney disease (OR = 2.66 (1.101–6.99)), thyroid disease (OR = 1.81 (1.18–2.79)), gout/high uric acid levels (OR = 2.08 (1.22–3.56)) and osteoporosis (OR = 1.69 (1.01–2.84)). In men, CHD patients were more likely to have hypertension (OR = 2.80 (1.94–4.04)), diabetes mellitus (OR = 1.87 (1.29–2.71)), lipid disorder (OR = 1.82 (1.34–2.47)), and chronic kidney disease (OR = 3.28 (1.81–5.9)).

Conclusion

Our analysis revealed two sets of chronic conditions associated with CHD. The first set occurred in both women and men, and comprised known risk factors: hypertension, lipid disorders, kidney disease, and diabetes mellitus. The second set appeared unique to women: thyroid disease, osteoporosis, and gout/high uric acid. Identification of shared and unique gender-related associations between CHD and other conditions provides potential to tailor screening, preventive, and therapeutic options.

Novel bisphosphonate compound FYB-931 preferentially inhibits aortic calcification in vitamin D3-treated rats

In patients with chronic kidney disease (CKD) or those undergoing hemodialysis, pathological calcific deposition known as ectopic calcification occurs in soft tissue, resulting in a life-threatening disorder. A potent and effective inhibitor of ectopic calcification is eagerly expected. In the current study, the effects of FYB-931, a novel bisphosphonate compound synthesized for the prevention of ectopic calcification, were compared with those of etidronate using both in vitro and in vivo models. In vitro, FYB-931 inhibited calcification of human aortic smooth muscle cells induced by high phosphate medium in a concentration-dependent manner, and the effect was slightly more potent than that of etidronate. In vivo, rats were administered with three subcutaneous injections of vitamin D3 to induce vascular calcification, and were given FYB-931 (1.5, 5, or 10 mg/kg) or etidronate (9, 30, or 60 mg/kg) orally once daily for 14 days. The increased aortic phosphorus content as an index of vascular calcification was inhibited by both FYB-931 and etidronate in a dose-dependent manner; however, FYB-931 was 10 times more potent than etidronate. FYB-931 inhibited serum tartrate-resistant acid phosphatase (TRACP) activity as a bone resorption marker 5.2 times more potently than etidronate. FYB-931, but not etidronate, significantly decreased serum phosphorus levels. The preferential inhibition of aortic calcification by FYB-931 suggested that possible additional effect including a decline in serum phosphorus may lead to an advantage in terms of its efficacy.

Calcification of abdominal aorta in patients recently starting hemodialysis: A single-center experience from Egypt

Vascular calcification (VC) is a well-known complication in patients with chronic kidney disease (CKD). Keeping in mind, the end goal to assess the genuine effect of mineral bone disease in the pathogenesis of blood vessel calcification during the pre-dialysis course of CKD, we assessed the prevalence and extent of abdominal aortic calcification (AAC) in nondiabetic CKD patients recently starting hemodialysis (HD). Eighty-one patients with end-stage renal disease beginning HD over a one-month period were selected. They underwent a detailed clinical examination and laboratory evaluation, including serum calcium, phosphorus, parathyroid hormone, fibroblast growth factor (FGF-23), and alkaline phosphatase were measured, and spiral computed tomography was performed to evaluate AAC score. AAC was present in 64 patients (79%). There was a significant correlation between the AAC score and age (r = 0.609, P <0.001) and FGF-23 (r = 0.800, P <0.001). This study suggests that the prevalence and extent of AAC are critical in incident HD patients. Serum FGF-23 level is the sole statistically significant correlate of AAC in these patients.

Association of non-invasive measures of subclinical atherosclerosis and arterial stiffness with mortality and major cardiovascular events in chronic kidney disease: systematic review and meta-analysis of cohort studies

Background

Non-invasive cardiovascular disease (CVD) risk prediction, in subclinical stages, aiming to stratify patients and tailor interventions remains an unmet need in chronic kidney disease (CKD). In this meta-analysis, we summarize the association of carotid intima-media thickness (cIMT), coronary artery calcium score (CACS) and pulse wave velocity (PWV) with all-cause mortality, cardiovascular (CV) mortality and CV events in non-dialysis CKD and patients on haemodialysis.

Methods

Systematic review and meta-analysis of prospective cohort studies.

Results

Out of 27 984 records, a total of 45 studies were eligible for quantitative synthesis; 11 for cIMT, 18 for CACS and 16 for PWV involving 2235, 4904 and 5717 patients, respectively. Meta-analysis was possible from pooled data of five cIMT studies (708 subjects), eight CACS studies (862 subjects) and nine PWV studies (1508 subjects). In dialysis patients, cIMT was associated with all-cause mortality [relative risk (RR) per unit increase: 1.08, 95% confidence interval (CI) 1.00-1.17, I ²: 68%] and CV mortality (RR: 1.29, 95% CI 1.14-1.47, I ²: 0%). High versus low CACS was associated with all-cause mortality (RR: 2.51, 95% CI 1.66-3.79, I ²: 5.7%) and CV events (RR: 3.77 95% CI 2.16-6.58, I ²: 20.2%). High versus low PWV was associated with all-cause (RR: 5.34, 95% CI 3.01-9.47, I ²: 0%) and CV mortality (RR: 8.55, 95% CI 4.37-16.73, I ²: 0%). The combined estimated for all-cause mortality per 1 m/s increment unit in PWV was 1.25 (95% CI 1.17-1.34, I ²: 0%) and for CV mortality was 1.24 (95% CI 1.16-1.34, I ²: 15.5%). In non-dialysis patients, CACS was associated with CV events (RR: 4.02, 95% CI 1.57-10.29, I ²: 63.4%). High versus low PWV was associated with all-cause mortality (RR: 2.52, 95% CI 1.40-4.55, I ²: 62.6%).

Conclusions

Non-invasive measures of atherosclerosis and arterial stiffening are associated with all-cause and CV mortality as well as CV events among patients with all stages of CKD. These markers could be considered for the evaluation of CV morbidity and mortality risks. Moreover, the results of this meta-analysis support the study of interventions, with effect on these markers of vascular disease, on long-term CVD outcomes.

The assessment of coronary artery disease in patients with end-stage renal disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality among patients with end-stage renal disease (ESRD). Clustering of traditional atherosclerotic and non-traditional risk factors drive the excess rates of coronary and non-coronary CVD in patients with ESRD. Coronary artery disease (CAD) is a key disease process, present in ∼50% of the haemodialysis population ≥65 years of age. Patients with ESRD are more likely to be asymptomatic, posing a challenge to the correct identification of CAD, which is essential for appropriate risk stratification and management. Given the lack of randomized clinical trial evidence in this population, current practice is informed by observational data with a significant potential for bias. For this reason, the most appropriate approach to the investigation of CAD is the subject of considerable discussion, with practice patterns largely varying between different centres. Traditional imaging modalities are limited in their diagnostic accuracy and prognostic value for cardiac events and survival in patients with ESRD, demonstrated by the large number of adverse cardiac outcomes among patients with negative test results. This review focuses on the current understanding of CAD screening in the ESRD population, discussing the available evidence for the use of various imaging techniques to refine risk prediction, with an emphasis on their strengths and limitations.

Cardiac risk assessment for end-stage renal disease patients on the renal transplant waiting list

Cardiovascular disease is a leading cause of morbidity and mortality and is becoming more prevalent as the population ages and risk factors increase. This is most apparent in the end-stage renal disease (ESRD) patient population. In part, this is due to cofactors such as diabetes and hypertension commonly predisposing to progressive renal disease, as well as being a direct consequence of having renal failure. Of all major organ failures, kidney failure is the most likely to be managed chronically using renal replacement therapy and, ultimately, transplant. However, lack of transplant organs and a large renal failure cohort means waiting lists are often quite long and may extend to 5-10 years. Due to the cardiac risk factors inherent in patients awaiting transplant, many succumb to cardiac issues while waiting and present an increased per-procedural cardiac risk that extends into the post-transplant period. We aim to review the epidemiology of coronary artery disease in this population and the etiology as it relates to ESRD and its associated co-factors. We also will review the current approaches, recommendations and evidence for management of these patients as it relates to transplant waiting lists before and after the surgery. Recommendations on how to best manage patients in this cohort revolve around the available evidence and are best customized to the institution and the structure of the program. It is not clear whether the revascularization of patients without symptoms and with a good functional status yields any improvement in outcomes. Therefore, each individual case should be considered based on the risk factors, symptoms and functional status, and approached as part of a multi-disciplinary assessment program.

Hypercalcemia Is a Risk Factor for the Progression of Aortic Calcification in Kidney Transplant Recipients

BACKGROUND/AIMS

Vascular calcification is common and progressive in chronic kidney disease, including kidney transplant recipients (KTRs). However, the risk factors associated with the progression of aortic calcification (AoC) in KTRs have not been fully elucidated. In the present study, we evaluated AoC and examined the factors associated with its advancement in KTRs.

MATERIALS

This was a prospective longitudinal study that included 98 KTRs. We quantitatively investigated infrarenal abdominal AoC using the Agatston score, as measured by multi-slice computed tomography. After the baseline investigation, a follow-up scan was performed after 3 years, and the Agatston scores were obtained again. The changes in laboratory data affecting the 2nd Agatston scores were examined by multivariable analysis using non-linear regression after adjustment for several confounders.

RESULTS

The 2nd Agatston scores were significantly greater than the baseline Agatston scores (p < 0.001). After adjustment for the confounders, the change in corrected serum calcium exhibited a significant non-linear correlation with the 2nd Agatston scores (p = 0.022 for non-linearity/p = 0.031 for the effect of corrected serum calcium). Moreover, an interaction was present from the baseline AoC in the effect of corrected serum calcium on the progression of AoC, and the effect of hypercalcemia was greater in patients with higher baseline Agatston scores (p = 0.049).

CONCLUSION

The present study revealed that hypercalcemia is a risk factor for the development of infrarenal abdominal AoC in KTRs. Furthermore, the effect of hypercalcemia was greater in patients with more severe vascular calcification.

Coronary calcification as a predictor of cardiovascular mortality in advanced chronic kidney disease: a prospective long-term follow-up study

BACKGROUND

Patients with advanced chronic kidney disease (CKD) exhibit higher prevalence of coronary artery calcification (CaC) than general population. CaC has been proposed as a risk factor for mortality in end-stage CKD, but most studies in the field are based on short-term follow-up.

METHODS

We conducted a cohort, 10-year prospective longitudinal study of consecutive cases referred to the renal unit. A non-enhanced multislice coronary computed tomography was performed at baseline. CaC was assessed by Agatston method. Patients were stratified according to their CaC score: severe calcification group (CaCs< 400 HU) and mild-moderate calcification group (CaCs≥400 HU). The overall and cardiovascular (CV) mortality, CV events, and factors potentially associated with CaC development were recorded.

RESULTS

137 patients with advanced CKD were enrolled and provided consent. Overall mortality rate was 58%; 40% due to CV events. The rate of overall mortality in the severe calcification group was 75%, and 30% in the low calcification group, whereas the rate of CV mortality was 35% vs. 6%, respectively (p < 0.001). The severe calcification group was older, had higher prevalence of type 2 diabetes mellitus, former cardiologic events, and lower albumin serum levels than the mild-moderate calcification group. In a multivariate Cox model, severe CaC was a significant predictor of CV mortality (HR 5.01; 95%CI 1.28 to 19.6, p = 0.02).

CONCLUSIONS

Among advanced CKD, there was a significantly increase of CV mortality in patients with severe CaCs during a 10-year follow-up period. CaCs could be a useful prognostic tool to predict CV mortality risk in CKD patients.

The Predictive Value of Coronary Artery Calcium Scoring for Major Adverse Cardiac Events According to Renal Function (from the Coronary Computed Tomography Angiography Evaluation for Clinical Outcomes: An International Multicenter [CONFIRM] Registry)

The prognostic performance of coronary artery calcium score (CACS) for predicting adverse outcomes in patients with decreased renal function remains unclear. We aimed to examine whether CACS improves risk stratification by demonstrating incremental value beyond a traditional risk score according to renal function status. 9,563 individuals without known coronary artery disease were enrolled. Estimated glomerular filtration rate (eGFR, ml/min/1.73 m²) was ascertained using the modified Modification of Diet in Renal Disease formula, and was categorized as: ≥90, 60 to 89, and <60. CACS was categorized as 0, 1 to 100, 101 to 400, and >400. Multivariable Cox regression was used to estimate hazard ratios (HR) with 95% confidence intervals (95% CI) for major adverse cardiac events (MACE), comprising all-cause mortality, myocardial infarction, and late revascularization (>90 days). Mean age was 55.8 ± 11.5 years (52.8% male). In total, 261 (2.7%) patients experienced MACE over a median follow-up of 24.5 months (interquartile range: 16.9 to 41.1). Incident MACE increased with higher CACS across each eGFR category, with the highest rate observed among patients with CACS >400 and eGFR <60 (95.1 per 1,000 person-years). A CACS >400 increased MACE risk with HR 4.46 (95% CI 1.68 to 11.85), 6.63 (95% CI 4.03 to 10.92), and 6.14 (95% CI 2.85 to 13.21) for eGFR ≥90, 60 to 89, and <60, respectively, as compared with CACS 0. Further, CACS improved discrimination and reclassification beyond Framingham 10-year risk score (FRS) (AUC: 0.70 vs 0.64; category free-NRI: 0.51, all p <0.001) for predicting MACE in patients with impaired renal function (eGFR < 90). In conclusion, CACS improved risk stratification and provided incremental value beyond FRS for predicting MACE, irrespective of eGFR status.

Differences in association of lower bone mineral density with higher coronary calcification in female and male end-stage renal disease patients

Background

Risk of cardiac events and cardiovascular disease (CVD) in end-stage renal disease (ESRD) patients are predicted by coronary artery calcification (CAC) independently. It is not clear to what extent low bone mineral density (BMD) is associated with higher risk of CAC and if sex interacts. We investigated the sex-specific associations of CAC score with total body BMD (tBMD) as well as with BMD of different skeletal sub-regions.

Methods

In 174 ESRD patients, median age 57 (10th–90th percentiles 29–75) years, 63% males, BMD (measured by dual-energy X-ray absorptiometry; DXA), CAC score (measured by cardiac CT) and circulating inflammatory biomarkers were analysed.

Results

A total of 104 (60%) patients with CAC > 100 AUs were older, had higher prevalence of both clinical CVD and diabetes, higher level of high sensitivity C-reactive protein, tumour necrosis factor, interleukin-6 and lower T-score of tBMD. Female patients had significantly lower tBMD and BMD of all skeletal sub-regions, except head, than male patients. Female patients with high CAC (> 100 AUs) had significantly decreased T-score of tBMD, and lower BMD of arms, legs than those low CAC (≤ 100 AUs); elevated CAC score were associated with tBMD, T-score, Z-score of tBMD and BMD of arms and legs, while no such differences was observed in males. Multivariate generalized linear model (GLM) analysis adjusted for age, diabetes and hsCRP showed that in females per SD higher CAC score (1057 AUs) was predicted by either per SD (0.13 g/cm²) lower tBMD or per SD (0.17 g/cm²) lower BMD at legs. No such associations were found in male ESRD patients.

Conclusions

In female, but not male, lower BMD, in particular sub-regions of legs, was associated with higher CAC score independently. Low BMD has the potential to identify increased risk for high CAC score in ESRD patients.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1235-z) contains supplementary material, which is available to authorized users.

Coronary artery calcification in patients with diabetes mellitus and advanced chronic kidney disease

INTRODUCTION

Patients with chronic kidney disease (CKD) and diabetes mellitus (DM) have high cardiovascular risk. Both conditions are related to systemic atherosclerosis and vascular calcification. The prevalence and severity of coronary artery calcification (CaC) is higher in patients with DM, regardless of their renal function. Data about the long-term prognostic role of CaC in diabetic patients with CKD are scarce.

MATERIAL AND METHODS

We carried out a prospective longitudinal study enrolling 137 patients with advanced CKD. A non-enhanced multislice coronary computed tomography (CT) was performed at baseline. CaC was assessed using Agatston method. Patients were stratified according to their CaC score: severe calcification group (CaCs≥400HU) and mild-moderate calcification group (CaCs<400HU).

RESULTS

The median follow-up time was 87.5 months. DM was found in 28% of subjects. The patients with DM showed more severe CaC, lower albumin and higher C-reactive protein serum levels. Serum albumin was correlated with severe CaC (r=-0.45, P=.009). Overall mortality rate reached 58%. Patients with DM also tended to have higher mortality compared to non-diabetic subjects (X² 3.51, P=.061) especially those with severe CaC showed higher mortality than those with severe CaC without DM (93% vs.73%, P=.04).

CONCLUSIONS

Patients with advanced CKD and DM have more severe CaC, increased inflammation-malnutrition data and higher mortality compared to those without DM.

Evaluation of the coronary circulation and calcification in children on regular hemodialysis

BACKGROUND

The objective of this study was to evaluate the coronary circulation and calcification in children with end-stage renal disease (ESRD) on hemodialysis.

METHODS

A total of 50 children with ESRD and 50 healthy controls were enrolled in the study. Cardiac functions and coronary blood flow were evaluated with conventional and tissue Doppler echocardiography. Coronary artery calcification (CAC) was evaluated using high-resolution multidetector computed tomography (CT).

RESULTS

The hyperemic coronary flow volume (CFV) and coronary flow reserve were significantly lower in the patient group than in the controls, while there was no significant difference in the baseline CFV between the two groups. Hypertension was present in 60% and CAC was observed in 20% of the children in the patient group. CAC was present in 30% of the children in the hypertensive subgroup. The left ventricle myocardial performance index (LV MPI), CAC score, duration of hypertension and level of diastolic blood pressure were independent predictors of the coronary blood flow, and LV MPI, serum parathyroid hormone, duration of dialysis and E'/A' mitral valve were independent predictors of coronary calcification.

CONCLUSION

High diastolic blood pressure, long duration of hypertension, high LV MPI and increased CAC scores are independent risk factors for impaired coronary blood flow in children with ESRD.

Bone mineral density of extremities is associated with coronary calcification and biopsy-verified vascular calcification in living-donor renal transplant recipients

Chronic kidney disease (CKD) mineral and bone disorders (CKD-MBD) may lead to low bone mineral density (BMD) and vascular calcification (VC), but links to the latter are unclear. Here we investigated associations between BMD, coronary artery calcium (CAC) scores, and histological signs of VC in end-stage renal disease (ESRD) patients undergoing living-donor kidney transplantation (LD-Rtx). In 66 ESRD patients (median age 45 years, 68% males), BMD (by dual-energy X-ray absorptiometry, DXA), CAC score (by computed tomography, CT; n = 54), and degree of VC score (graded by histological examination of epigastric artery specimens collected at LD-Rtx; n = 55) were assessed at the time of LD-Rtx. Of the patients, 26% had osteopenia and 7% had osteoporosis. Of those undergoing artery biopsy, 16% had extensive VC, and of those undergoing CT 28% had high CAC score (>100 Agatston units). CAC scores correlated with BMD of legs and pelvis. BMDs of leg and pelvic sub-regions were significantly lower in patients with extensive VC. In multivariate regression analysis adjusted for age and gender, lower BMD of leg sub-region was associated with CAC score >100 AUs and extensive VC, and patients with extensive VC had significantly higher CAC score. Both high CAC and extensive VC were independently predicted by low BMD of legs. Low BMD has the potential to identify ESRD patients at risk of vascular calcification.

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.

Renal function had an independent relationship with coronary artery calcification in Chinese elderly men

BACKGROUND

Although previous studies have analyzed the relationship between renal function and coronary artery calcification (CAC) in pre-dialysis and dialysis patients, limited studies have discussed the relationship between renal function and CAC in Chinese elderly men without obvious damage of renal function. The present study was designed to explore the relationship between renal function and CAC in Chinese elderly men without obvious damage of renal function.

METHODS

This cross-sectional study was carried out in 105 male participants older than 60 years with glomerular filtration rate (GFR) ≥ 45 ml/min/1.73 m². CAC was detected by high-definition computerized tomography (HDCT), which is a highly sensitive technique for detecting the CAC and provides the most accurate CAC scores up to date.

RESULTS

Age was 72 ± 8.4 years on average and ranged from 60 to 89 years. Simple correlation analysis indicated that all kinds of CAC scores including the Agatston, volume and mass scores inversely correlated with GFR values (p < 0.05 for all). In multivariate linear regression analysis, GFR values were independently associated with all these CAC scores (p < 0.05 for all).

CONCLUSION

Renal function had an independent relationship with CAC detected by HDCT in Chinese elderly men, demonstrating that the relationship between renal function and CAC started at the early stage of renal function decline.

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.

Effects of Magnesium on the Phosphate Toxicity in Chronic Kidney Disease: Time for Intervention Studies

Magnesium, an essential mineral for human health, plays a pivotal role in the cardiovascular system. Epidemiological studies in the general population have found an association between lower dietary magnesium intake and an elevated risk of cardiovascular events. In addition, magnesium supplementation was shown to improve blood pressure control, insulin sensitivity, and endothelial function. The relationship between magnesium and cardiovascular prognosis among patients with chronic kidney disease (CKD) has been increasingly investigated as it is becoming evident that magnesium can inhibit vascular calcification, a prominent risk of cardiovascular events, which commonly occurs in CKD patients. Cohort studies in patients receiving dialysis have shown a lower serum magnesium level as a significant risk for cardiovascular mortality. Interestingly, the cardiovascular mortality risk associated with hyperphosphatemia is alleviated among those with high serum magnesium levels, consistent with in vitro evidence that magnesium inhibits high-phosphate induced calcification of vascular smooth muscle cells. Furthermore, a harmful effect of high phosphate on the progression of CKD is also attenuated among those with high serum magnesium levels. The potential usefulness of magnesium as a remedy for phosphate toxicity should be further explored by future intervention studies.

Vertebral bone density associates with coronary artery calcification and is an independent predictor of poor outcome in end-stage renal disease patients

OBJECTIVE

Chronic kidney disease-mineral bone disorder (CKD-MBD) is a major complication of end-stage renal disease (ESRD). Reduced bone mineral density (BMD) is associated with vascular calcification. Here we investigated associations between vertebral bone density (VBD) and coronary artery calcification (CAC), quantified by cardiac computed tomography (CT), and BMD quantified by dual-energy X-ray absorptiometry (DXA), and their relations with mortality.

METHODS

In 231 ESRD patients (median age 56years, 63% males) comprising incident dialysis patients, prevalent peritoneal dialysis patients and recipients of living donor kidney transplant, VBD (Hounsfield units, HUs) and CAC scores (Agatston units, AUs) were quantified by cardiac CT, and, in 143 of the patients, BMD was measured by DXA of total body. Metabolic and inflammation biomarkers potentially linked to CKD-MBD were also analysed.

RESULTS

Patients with low tertile of VBD were older and had more often cardiovascular disease (CVD), and higher HbA1c (non-diabetics), interleukin-6 and CAC score. Low VBD was independently associated with higher CAC score (>100 AUs) after adjustment for age, gender, diabetes, CVD, inflammation and cohorts. In Cox proportional hazards analysis, low VBD was independently associated with all-cause mortality after adjustment for age, gender, diabetes, CVD, inflammation and subjective global assessment (SGA). The root mean-squared error of prediction (RMSE) showed a good degree of association between VBD and BMD evaluated from DXA. In receiver-operator characteristics curve (ROC) analysis, lower VBD was more strongly associated with higher CAC score and all-cause mortality than BMD evaluated from DXA.

CONCLUSIONS

While assessments of BMD by DXA and CT showed good degree of agreement, associations of high CAC, and mortality, with low VBD were stronger than those based on low BMD by DXA. The strong independent associations of low VBD with high CAC score and increased mortality risk suggest that VBD may serve as an important prognosticator in ESRD patients.

Association between Density of Coronary Artery Calcification and Serum Magnesium Levels among Patients with Chronic Kidney Disease

Background

The Agatston score, commonly used to quantify coronary artery calcification (CAC), is determined by the plaque area and density. Despite an excellent predictability of the Agatston score for cardiovascular events, the density of CAC has never been studied in patients with pre-dialysis chronic kidney disease (CKD). This study aimed to analyze the CAC density and its association with serum mineral levels in CKD.

Methods

We enrolled patients with pre-dialysis CKD who had diabetes mellitus, prior cardiovascular disease history, elevated low-density lipoprotein cholesterol levels, or smoking history. The average CAC density was calculated by dividing the Agatston score by the total area of CAC.

Results

The mean estimated glomerular filtration rate (eGFR) of 109 enrolled patients was 35.7 mL/min/1.73 m². The correlation of the Agatston score with density was much weaker than that with the total area (R² = 0.19, P < 0.001; and R² = 0.99, P < 0.001, respectively). Multivariate analyses showed that serum magnesium level was inversely associated with the density, but not with the total area, after adjustment for demographics and clinical factors related to malnutrition-inflammation-atherosclerosis syndrome and mineral and bone disorders including fibroblast growth factor 23 (P = 0.006). This inverse association was pronounced among patients with higher serum phosphate levels (P for interaction = 0.02).

Conclusion

CAC density was inversely associated with serum magnesium levels, particularly in patients with higher serum phosphate levels.

Assessment of abdominal aortic calcification at different stages of chronic kidney disease

PURPOSE

Vascular calcifications that may cause cardiovascular disease are highly prevalent in chronic kidney disease (CKD). In this study, we aimed to determine abdominal aorta calcifications (AAC) in predialysis and hemodialysis patients by lateral lumbar radiography and to investigate factors that were associated with the calcifications.

METHODS

Two hundred and fifty-nine adult chronic hemodialysis patients, 300 predialysis CKD patients and 60 healthy subjects with normal kidney function as a control group were enrolled in the study. Lateral lumbar radiography was used to measure AAC. Calcified deposits of the abdominal aorta wall at the level of the first through fourth lumbar vertebrae were graded by a 24-point scoring system.

RESULTS

AAC prevalence (AAC score ≥1) was significantly different in hemodialysis, predialysis and control groups (71.8, 45.7 and 33.3 %, respectively; p < 0.001). AAC prevalence in CKD stages 1, 2, 3, 4 and 5 predialysis patients was 26.6, 43.3, 40, 58.3 and 55 %, respectively. AAC scores of the hemodialysis group were higher than of the predialysis group (p < 0.001) and the control group (p < 0.001). AAC scores of the predialysis group were not higher than of the control group (p = 0.314). AAC scores of the hemodialysis group were significantly higher than of the control group (p < 0.001) and stage 1 (p < 0.001), stage 2 (p = 0.001) and stage 3 predialysis groups (p = 0.002). Age (p < 0.001), presence of diabetes mellitus (p < 0.001) and serum phosphorus levels (p = 0.011) were found to be independent predictors of calcification in the hemodialysis group. Age (p < 0.001), serum phosphorus levels (p = 0.007) and history of cardiovascular disease (p = 0.014) were found to be independent predictors of calcification in the predialysis group.

CONCLUSIONS

Abdominal aortic calcification is highly prevalent in the hemodialysis population. Strict phosphorus control should be implemented to the predialysis and hemodialysis patients.

Vascular calcification: When should we interfere in chronic kidney disease patients and how?

Chronic kidney disease (CKD) patients are endangered with the highest mortality rate compared to other chronic diseases. Cardiovascular events account for up to 60% of the fatalities. Cardiovascular calcifications affect most of the CKD patients. Most of this calcification is related to disturbed renal phosphate handling. Fibroblast growth factor 23 and klotho deficiency were incriminated in the pathogenesis of vascular calcification through different mechanisms including their effects on endothelium and arterial wall smooth muscle cells. In addition, deficient klotho gene expression, a constant feature of CKD, promotes vascular pathology and shares in progression of the CKD. The role of gut in the etio-pathogenesis of systemic inflammation and vascular calcification is a newly discovered mechanism. This review will cover the medical history, prevalence, pathogenesis, clinical relevance, different tools used to diagnose, the ideal timing to prevent or to withhold the progression of vascular calcification and the different medications and medical procedures that can help to prolong the survival of CKD patients.

Protective Effect of Myo-Inositol Hexaphosphate (Phytate) on Abdominal Aortic Calcification in Patients With Chronic Kidney Disease

OBJECTIVE

The aim of this study was to evaluate the relationship between physiological levels of myo-inositol hexaphosphate (phytate) and cardiovascular (CV) calcification in patients with chronic kidney disease (CKD).

DESIGN AND METHODS

This was a prospective cross-sectional study conducted from December 2012 to June 2013.

SUBJECTS

Sixty-nine consecutive patients with CKD who were not undergoing renal replacement therapy.

INTERVENTION

All subjects were given lateral lumbar X-rays to quantify abdominal aortic calcification (AAC). Clinical laboratory analyses and phytate food frequency questionnaires were also performed.

MAIN OUTCOME MEASURE

Phytate urinary excretion, estimated phytate consumption (based on food frequency questionnaire) and AAC score. Patients were divided into two groups based on median abdominal aortic calcification (AAC) score: no/mild AAC (AAC ≤ 6, n = 35) and moderate/severe AAC (AAC > 6, n = 34).

RESULTS

Patients with no/mild AAC were younger, had lower pulse pressure, greater dietary intake of phytate, greater urinary phytate and the prevalence of prior CV disease was significantly lower compared to patients with moderate/severe AAC. Among the top 10 phytate-rich foods, lentil consumption was significantly greater in patients with no/mild AAC than in those with moderate/severe AAC. Multivariate logistic regression analysis indicated that age, prior CV disease, urinary phytate (or lentil consumption) were independently associated to AAC.

CONCLUSION

Our results suggest that adequate consumption of phytate can prevent AAC in patients with CKD. Further prospective studies must be performed to elucidate the benefits of a phytate-rich diet and the associated risk of phosphorus bioavailability in these patients.

Clinical imaging of vascular disease in chronic kidney disease

Arterial wall calcification, once considered an incidental finding, is now known to be a consistent and strong predictor of cardiovascular events in patients with chronic renal insufficiency. It is also commonly encountered in radiologic examinations as an incidental finding. Forthcoming bench, translational, and clinical data seek to establish this and pre-calcification changes as surrogate imaging biomarkers for noninvasive prognostication and treatment follow-up. Emerging paradigms seek to establish vascular calcification as a surrogate marker of disease. Imaging of pre-calcification and decalcification events may prove more important than imaging of the calcification itself. Data-driven approaches to screening will be necessary to limit radiation exposure and prevent over-utilization of expensive imaging techniques.

Screening for cardiovascular disease before kidney transplantation

Pre-kidney transplant cardiac screening has garnered particular attention from guideline committees as an approach to improving post-transplant success. Screening serves two major purposes: To more accurately inform transplant candidates of their risk for a cardiac event before and after the transplant, thereby informing decisions about proceeding with transplantation, and to guide pre-transplant management so that post-transplant success can be maximized. Transplant candidates on dialysis are more likely to be screened for coronary artery disease than those not being considered for transplantation. Thorough history and physical examination taking, resting electrocardiography and echocardiography, exercise stress testing, myocardial perfusion scintigraphy, dobutamine stress echocardiography, cardiac computed tomography, cardiac biomarker measurement, and cardiac magnetic resonance imaging all play contributory roles towards screening for cardiovascular disease before kidney transplantation. In this review, the importance of each of these screening procedures for both coronary artery disease and other forms of cardiac disease are discussed.

Assessment of the relationship between selected cardiovascular risk factors and the indices of intima-media thickness and coronary artery calcium score in various stages of chronic kidney disease

Renal diseases pose a growing epidemiological and health problem worldwide. Cardiovascular diseases are the leading cause of deaths among patients with chronic kidney disease. Increased risk of atherosclerosis in these patients results from the occurrence of traditional and non-traditional risk factors. The aim of this study was to assess the relationship between selected risk factors for cardiovascular diseases (age, sex, dyslipidemia, hypertension, etc.), intima-media thickness and coronary artery calcium score in patients with chronic kidney disease stages 2, 3 and 4. This study included 60 patients with chronic kidney disease divided into 3 groups on the basis of disease stage and control group consisting of 20 individuals without diagnosed chronic kidney disease and cardiovascular diseases. Blood analysis and blood pressure measurements were taken. All patients underwent carotid artery ultrasound with the assessment of the intima-media thickness, and heart CT scan in order to assess the index of coronary artery calcification. Logistic regression analysis revealed statistically significant correlation between blood vessels calcification and age--the increase in age by 1 year was associated with the increase in the risk of coronary artery calcification by 6.7 %. The increase in IMT by about 0.1 mm raises the risk of calcification by about 2 %. Second logistic regression model revealed that one-year increase in age was associated with an increase in the risk of intima-media thickening by 6.5 %. Occurrence of hypertension was associated with a ninefold increase in intima-media thickening risk in comparison with patients with normal blood pressure. To sum up, age and hypertension were associated with the growth of IMT in CKD patients, while age and exposure to tobacco smoke were associated with the increase in coronary artery calcium score. The relationship between thickening of IMT and the increase in calcification index in patients was also observed in study group.

Arteriosclerosis and vascular calcification: causes, clinical assessment and therapy

BACKGROUND

Arteriosclerosis is a pathological, structural (media vascular calcification) and physiological (modified vascular smooth vessel cells; increased arterial stiffness) alteration of the vessel wall. Through improved assessment methods (functional and imaging), it has become a well-known phenomenon in recent decades. However, its clinical importance was underestimated until recently.

MATERIALS AND METHODS

Currently available English-speaking data about conditions/diseases associated with arteriosclerosis, its clinical sequels, available diagnostic procedures and therapeutic modalities were reviewed and summarized.

RESULTS

In recent decades, emerging data have brought about a better understanding of causes and consequences of arteriosclerosis and highlight its growing clinical impact.

CONCLUSION

Although arteriosclerosis showed an independent clinical impact on cardiovascular morbidity and mortality, especially in patients with chronic kidney disease/end-stage renal disease (CKD/ESRD) and diabetes mellitus, convincing clinical therapy concepts are not available until now. The establishment of novel therapeutic strategies derived from basic research is strongly needed.

Coronary artery calcification, cardiovascular events, and death: a prospective cohort study of incident patients on hemodialysis

Background

Coronary calcification in patients with end-stage renal disease (ESRD) is associated with an increased risk of cardiovascular outcomes and death from all causes. Previous evidence has been limited by short follow-up periods and inclusion of a heterogeneous cluster of events in the primary analyses.

Objective

To describe coronary calcification in patients incident to ESRD, and to identify whether calcification predicts vascular events or death.

Design

Prospective substudy of an inception cohort.

Setting

Tertiary care haemodialysis centre in Ontario (St Joseph’s Healthcare Hamilton).

Participants

Patients starting haemodialysis who were new to ESRD.

Measurements

At baseline, clinical characterization and spiral computed tomography (CT) to score coronary calcification by the Agatston-Janowitz 130 scoring method. A primary outcome composite of adjudicated stroke, myocardial infarction, or death.

Methods

We followed patients prospectively to identify the relationship between cardiac calcification and subsequent stroke, myocardial infarction, or death, using Cox regression.

Results

We recruited 248 patients in 3 centres to our main study, which required only biochemical markers. Of these 164 were at St Joseph’s healthcare, and eligible to participate in the substudy; of these, 51 completed CT scanning (31 %). Median follow up was 26 months (Q₁, Q₃: 14, 34). The primary outcome occurred in 16 patients; 11 in the group above the median and 5 in the group below (p = 0.086). There were 26 primary outcomes in 16 patients; 20 (77 %) events in the group above the coronary calcification median and 6 (23 %) in the group below (p = 0.006). There were 10 deaths; 8 in the group above the median compared with 2 in the group below (p = 0.04). The hazard ratios for coronary calcification above, compared with below the median, for the primary outcome composite were 2.5 (95 % CI 0.87, 7.3; p = 0.09) and 1.7 (95 % CI 0.55, 5.4; p = 0.4), unadjusted and adjusted for age, respectively. For death, the hazard ratios were 4.6 (95 % CI 0.98, 21.96; p = 0.054) and 2.4 (95 % CI 0.45, 12.97; p = 0.3) respectively.

Limitations

We were limited by a small sample size and a small number of events.

Conclusions

Respondent burden is high for additional testing around the initiation of dialysis. High coronary calcification in patients new to ESRD has a tendency to predict cardiovascular outcomes and death, though effects are attenuated when adjusted for age.

Vascular calcification burden of Chinese patients with chronic kidney disease: methodology of a cohort study

Background

Vascular calcification is a common complication associated with chronic kidney disease and the major cause of cardiovascular disease in patients with end-stage renal disease. The vascular calcification risk burden is still unknown in China. This study aims to investigate the prevalence of vascular calcification and assess the predictive value of vascular calcification in patients with stage 5 chronic kidney disease on dialysis in China.

Methods/Design

This is a national, multicenter, non-interventional, prospective cohort study planning to recruit 1520 patients with end-stage renal disease receiving hemodialysis or peritoneal dialysis for at least 6 months in 24 dialysis centers in China. All the patients provided written informed consents before participating in this study. It will include a baseline visit and 24 months follow-up period with 4 other visits at 6-month intervals. Vascular calcification images will be obtained to determine the prevalence of vascular calcification, coronary artery calcification, abdominal aortic calcification and cardiac valve calcification. Association between vascular calcification and all-cause and cardiovascular disease mortality and non-fatal cardiovascular events will be assessed. Disease management, as assessed by serum level of calcium, phosphorus and intact parathyroid hormone and its impact on vascular calcification, will also be surveyed.

Discussion

The new results gained from this study will supplement limited current available data and provide better clinical decisions in Chinese patients with chronic kidney disease on dialysis.

Screening and risk stratification of coronary artery disease in end-stage renal disease

End-stage renal disease (ESRD) is a growing global health problem with major health and economic implications. Cardiovascular complication is the major cause of morbidity and mortality in this population. Clustering of traditional atherosclerotic risk factors, such as diabetes, systemic inflammation, and altered mineral metabolism, contributes to enhanced systemic atherosclerosis in patients with ESRD. Prevalence of obstructive coronary artery disease (CAD) on coronary angiography exceeds 50% in this population. Despite having extensive CAD and vascular disease, patients with ESRD often do not present with classic symptoms because of impaired exercise capacity and diabetes. Furthermore, clinical trial data are exceedingly lacking in this population, resulting in considerable clinical equipoise regarding the optimal approach to the identification and subsequent management of CAD in these patients. Traditional clinical screening tools, including conventional risk prediction models, are significantly limited in their predictive accuracy for cardiovascular events in patients with ESRD. Noninvasive cardiac stress imaging modalities, such as nuclear perfusion and echocardiography, have been shown to improve the traditional clinical model in identifying the presence of CAD. Furthermore, they add incremental prognostic information to angiographic data. Novel imaging techniques and biomarker assays hold significant promise in further improving the ability to identify and risk-stratify for CAD. This review focuses on the current understanding of the clinical risk profile of asymptomatic patients with ESRD with an emphasis on the strengths and limitations of various noninvasive cardiovascular imaging modalities, including the role of novel methods in refining risk prediction. In addition, issues and challenges pertaining to the optimal timing of initial risk assessment ("screening") and possible repeat screening ("surveillance") are addressed. We also summarize the current data on the approach to the patient with ESRD being evaluated for transplantation in the context of recent guidelines and position statements by various professional societies.