Assessment of abdominal aortic calcification by computed tomography for prediction of latent left ventricular stiffness and future cardiovascular risk in pre-dialysis patients with chronic kidney disease: A single center cross-sectional study

Cardiac Imaging Biomarkers in Chronic Kidney Disease

Uremic cardiomyopathy (UC), the peculiar cardiac remodeling secondary to the systemic effects of renal dysfunction, is characterized by left ventricular (LV) diffuse fibrosis with hypertrophy (LVH) and stiffness and the development of heart failure and increased rates of cardiovascular mortality. Several imaging modalities can be used to obtain a non-invasive assessment of UC by different imaging biomarkers, which is the focus of the present review. Echocardiography has been largely employed in recent decades, especially for the determination of LVH by 2-dimensional imaging and diastolic dysfunction by pulsed-wave and tissue Doppler, where it retains a robust prognostic value; more recent techniques include parametric assessment of cardiac deformation by speckle tracking echocardiography and the use of 3D-imaging. Cardiac magnetic resonance (CMR) imaging allows a more accurate assessment of cardiac dimensions, including the right heart, and deformation by feature-tracking imaging; however, the most evident added value of CMR remains tissue characterization. T1 mapping demonstrated diffuse fibrosis in CKD patients, increasing with the worsening of renal disease and evident even in early stages of the disease, with few, but emerging, prognostic data. Some studies using T2 mapping highlighted the presence of subtle, diffuse myocardial edema. Finally, computed tomography, though rarely used to specifically assess UC, might provide incidental findings carrying prognostic relevance, including information on cardiac and vascular calcification. In summary, non-invasive cardiovascular imaging provides a wealth of imaging biomarkers for the characterization and risk-stratification of UC; integrating results from different imaging techniques can aid a better understanding of the physiopathology of UC and improve the clinical management of patients with CKD.

Clinical Significance of Trace Element Zinc in Patients with Chronic Kidney Disease

The trace element zinc is essential for diverse physiological processes in humans. Zinc deficiency can impair growth, skin reproduction, immune function, maintenance of taste, glucose metabolism, and neurological function. Patients with chronic kidney disease (CKD) are susceptible to zinc deficiency, which is associated with erythropoiesis-stimulating agent (ESA) hypo-responsive anemia, nutritional problems, and cardiovascular diseases as well as non-specific symptoms such as dermatitis, prolonged wound healing, taste disturbance, appetite loss, or cognitive decline. Thus, zinc supplementation may be useful for the treatment of its deficiency, although it often causes copper deficiency, which is characterized by several severe disorders including cytopenia and myelopathy. In this review article, we mainly discuss the significant roles of zinc and the association between zinc deficiency and the pathogenesis of complications in patients with CKD.

Assessment of aortic stiffness in computed tomography - methodology of radiological examination from 2000 to 2020

INTRODUCTION

Vascular elasticity may be a predictive factor of various diseases. Although stiffening is thought to be a natural consequence of ageing, it can be accelerated by a number of pathological conditions such as hypertension, diabetes, or renal diseases. Aim of the study was to discuss the methodology used to assess aortic stiffness, with particular emphasis on radiological examination.

MATERIAL AND METHODS

The PubMed and Google Scholar databases were screened from inception to the year 2000 by 2 independent analysts initially working separately and then comparing their results.

RESULTS

Assessment of stiffness can be divided into methods not requiring computed tomography scan, such as tonometry of carotid femoral pulse wave velocity, bioelectrical impedance analysis, and cardio ankle vascular index, and methods requiring it, such as multidetector row computed tomography - ECG gated, in which indexes such as aortic distensibility, aortic stiffness, and aortic compliance can be obtained with simultaneous calcification evaluation based on the Agatston score.

DISCUSSION

Aortic stiffness was corelated with left ventricular afterload, prehypertension, coronary artery plaques, prediction of coronary artery diseases, bone demineralization, chronic obstructive pulmonary diseases, and diabetes mellitus.

CONCLUSIONS

Being a factor of various severe diseases, aortic stiffness may play an important role in the early detection of patients requiring additional medical care.

Indoxyl Sulfate Activates NLRP3 Inflammasome to Induce Cardiac Contractile Dysfunction Accompanied by Myocardial Fibrosis and Hypertrophy

In patients with chronic kidney diseases (CKD), high serum indoxyl sulfate (IS) levels correlate with cardiac fibrosis and hypertrophy and thus a critical risk factor for heart failure. The aim of this study was to determine the effects of IS on cardiac function and inflammasome pathway in a rat model of CKD. We assessed the physiological and pathological changes and measured biomarkers of fibrosis and hypertrophy in the hearts of Dahl salt-sensitive (DS), DS hypertensive (DH), and DH IS-treated rats (DH + IS). Low left ventricular (LV) ejection fraction, LV dilatation, and advanced myocardial fibrosis and hypertrophy were observed in DH + IS, which resemble changes found in uremic cardiomyopathy. These changes were independent of renal function and blood pressure. RT-PCR and western blotting analysis showed upregulation of fibrosis and hypertrophy-related biomarkers and adhesion molecules in the hearts of DH + IS rats. IS activated aryl hydrocarbon receptor (AHR) pathway, nuclear factor kappa B p65 (NF-κB p65), and inflammasome in the myocardium of DH + IS rat. Moreover, IS upregulated the expression of critical NLRP3 inflammasome components (NLRP3, ASC, and procaspase-1) and increased production of IL-1β and IL-18. Finally, IS upregulated various inflammatory cytokines, such as MCP-1, TNF-α, IL-6, and TGFβ1, in the myocardium. Our results suggested that IS induced cardiac fibrosis and hypertrophy and impaired LV function through activation of cardiac NLRP3 inflammasome via the AHR/NF-κB pathway.

Association of maximal stress ergometry performance with troponin T and abdominal aortic calcification score in advanced chronic kidney disease

Background

Cardiac biomarkers Troponin T (TnT) and N-terminal pro-B-type natriuretic peptide (proBNP) and abdominal aortic calcification score (AAC) are associated with cardiovascular events and mortality in patients with chronic kidney disease (CKD). The effects of cardiac biomarkers and AAC on maximal exercise capacity in CKD are unknown and were studied.

Methods

One hundred seventy-four CKD 4–5 patients not on maintenance dialysis underwent maximal bicycle ergometry stress testing, lateral lumbar radiograph to study AAC, echocardiography and biochemical assessments.

Results

The subjects with proportional maximal ergometry workload (WMAX%) less than 50% of the expected values had higher TnT, proBNP, AAC, left ventricular end-diastolic diameter, left ventricular mass index, E/e’ and pulse pressure, and lower global longitudinal strain compared to the better performing patients. TnT (β = − 0.09, p = 0.02), AAC (β = − 1.67, p < 0.0001) and diabetes (β = − 11.7, p < 0.0001) remained significantly associated with WMAX% in the multivariable model. Maximal ergometry workload (in Watts) was similarly associated with TnT and AAC in addition to age, male gender, hemoglobin and diastolic blood pressure in a respective multivariate model.

AAC and TnT showed fair predictive power for WMAX% less than 50% of the expected value with AUCs of 0.70 and 0.75, respectively.

Conclusions

TnT and AAC are independently associated with maximal ergometry stress test workload in patients with advanced CKD.

Trial registration

http://www.ClinicalTrials.gov NCT04223726.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02251-y.

Arterial endothelial function, carotid artery intima-media thickness and abdominal aortic calcification in diabetic and nondiabetic CKD stage 4-5 patients not on dialysis

AIMS

We aimed to study the effect of diabetes (DM) on endothelial dysfunction assessed by flow-mediated vasodilatation (FMD), carotid intima-media thickness (cIMT) and abdominal aortic calcification score (AAC) in chronic kidney disease (CKD) stage 4-5 patients not on dialysis.

METHODS

Altogether 199 non-dialysis CKD stage 4-5 patients enrolled in the Chronic Arterial Disease, quality of life and mortality in chronic KIDney injury (CADKID) study with plain lumbar radiograph for the assessment of AAC were included. Data on cIMT and FMD were available for 172 and 161 patients, respectively.

RESULTS

Median age was 65 (IQR 54-76) years, 88 (44.2%) patients had DM and median eGFR was 12 (IQR 10-14) ml/min/1.73 m² in the study. FMD [controls: 3.3(2.0-6.7)% vs. DM-patients: 4.3(1.3-6.6)%, p = 0.73] and cIMT [controls: 0.65(0.58-0.87)mm vs. DM-patients: 0.67(0.59-0.81)mm, p = 0.65], were similar between the groups. AAC was higher in patients with DM [controls: 5(1-9) vs. DM-patients: 7(2-13), p = 0.01]. The significant multivariate determinants for AAC were older age (β = 0.22, p < 0.0001), pulse pressure (β = 0.05, p < 0.0001), DM (β = 1.33, p = 0.04) and ProBNP (per µg/l β = 0.18, p = 0.0008). AAC and cIMT were associated with incident cardiovascular death independent of DM.

CONCLUSIONS

DM is associated with increased AAC but not increased cIMT or attenuated FMD in advanced CKD patients.

Association between Serum Zinc Levels and Clinical Index or the Body Composition in Incident Hemodialysis Patients

Background: The relationships between serum zinc levels and body composition or clinical outcomes of incident hemodialysis (HD) patients remain unclear. Methods: This prospective observational study examined the relationships between serum zinc levels and clinical indexes, including body composition, in 142 incident HD patients using a bioelectrical impedance analysis. Patients were divided into three groups according to baseline serum zinc levels: tertile, <45, 45–59, and ≥60 µg/dL. The reference group was set as ≥60 µg/dL. Cox’s regression analysis was performed to investigate the relationships between serum zinc categories and cardiovascular events and all-cause mortality after adjustments for potential confounders. Results: Serum zinc levels positively correlated with the nutritional index and negatively correlated with fluid volume markers. In a mean follow-up of 2.5 years, there were 20 cases of cardiovascular events and 15 of all-cause mortality. In the Cox’s regression analysis for cardiovascular events and all-cause mortality, the hazard ratio increased with a decrease in serum zinc levels, but was not significant. Conclusion: Serum zinc levels were associated with nutritional and fluid volume markers in incident HD patients. To clarify the relationship between serum zinc levels and cardiovascular events or mortality, further studies with a larger number of cases will be necessary.

HbA1c and Aortic Calcification Index as Noninvasive Predictors of Pre-Existing Histopathological Damages in Living Donor Kidney Transplantation

We previously reported that allografts from living donors may have pre-existing histopathological damages, defined as the combination of interstitial fibrosis (ci), tubular atrophy (ct), and arteriolar hyalinosis (ah) scores of ≧1, according to the Banff classification. We examined preoperative characteristics to identify whether the degree of these damages was related to metabolic syndrome-related factors of donors. We conducted a single-center cross-sectional analysis including 183 living kidney donors. Donors were divided into two groups: chronic change (ci + ct ≧ 1 &cap; ah ≧ 1, n = 27) and control (n = 156). Preoperative characteristics, including age, sex, blood pressure, hemoglobin A1c (HbA1c), aortic calcification index (ACI), and psoas muscle index (PMI), were analyzed. Comparing the groups, the baseline estimated glomerular filtration rate was not significantly different; however, we observed a significant difference for ACI (p = 0.009). HbA1c (p = 0.016) and ACI (p = 0.006) were independent risk factors to predict pre-existing histopathological damages, whereas PMI was not. HbA1c correlated with ct scores (p = 0.035), and ACI correlated with ci (p = 0.005), ct (p = 0.021), and ah (p = 0.017). HbA1c and ACI may serve as preoperative markers for identifying pre-existing damages on the kidneys of living donors.

Rationale, design, and baseline characteristics of the Cardiovascular Prognostic COUPLING Study in Japan (the COUPLING Registry)

Vascular biomarkers, including the cardio-ankle vascular index (CAVI), are increasingly being recognized as important indicators of cardiovascular risk. CAVI has been shown to have good discriminative ability for detecting new-onset hypertension, but results of studies investigating cardiovascular risk prediction are inconsistent. Furthermore, there is a lack of data on the prognostic value of changes in CAVI over time. The Cardiovascular Prognostic Coupling study was designed to determine the impact of baseline CAVI and changes in CAVI on cardiovascular events in a Japanese cohort. The design of the ongoing, multicenter, prospective, observational registry and baseline characteristics of the enrolled population are reported. Eligible consecutive patients were aged ≥30 years, had ≥1 cardiovascular risk factor, and were being treated according to relevant Japanese guidelines. The primary outcome is time to onset of a major cardiovascular event (a composite of cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage, stroke of unknown etiology, myocardial infarction, cardiovascular intervention for angina pectoris, and sudden death). Screening and enrollment occurred over a period of 3 years, followed by ≥7 years of follow-up, with CAVI determined annually. A total of 5279 patients were registered, of whom 5109 had baseline data available and will be included in future analyses. Mean CAVI at baseline was 8.8 ± 1.4. The proportion of patients with CAVI of <8, 8-10 or >10 was 25.3%, 57.0%, and 17.7%, respectively. Data from this registry should provide information on the significance of baseline CAVI and change in CAVI as indicators of cardiovascular prognosis in a representative patient population.

Indoxyl Sulfate-induced Vascular Calcification is mediated through Altered Notch Signaling Pathway in Vascular Smooth Muscle Cells

Introduction: The aim of this study was to determine the role of Notch in indoxyl sulfate (IS)-induced vascular calcification (VC). Materials and methods: VC and expression of Notch-related and osteogenic molecules were examined in Dahl salt-sensitive (DS), DS hypertensive (DH), and DH IS-treated rats (DH+IS). The effects of IS on expression of Notch receptors, apoptotic activity, and calcification were examined in cultured aortic smooth muscle cells (SMCs). Results: Medial calcification was noted only in aortas and coronary arteries of DH+IS rats. Notch1, Notch3, and Hes-1 were expressed in aortic SMCs of all rats, but only weakly in the central areas of the media and around the calcified lesions in DH+IS rats. RT-PCR and western blotting of DH+IS rat aortas showed downregulation of Notch ligands, Notch1 and Notch3, downstream transcriptional factors, and SM22, and conversely, overexpression of osteogenic markers. Expression of Notch1 and Notch3 in aortic SMCs was highest in incubation under 500 μM IS for 24hrs, and then decreased time- and dose-dependently. Coupled with this decrease, IS increased caspase 3/7 activity and TUNEL-positive aortic SMCs. In addition, pharmacological Notch signal inhibition with DAPT induced apoptosis in aortic SMCs. ZVAD, a caspase inhibitor abrogated IS-induced and DAPT-induced in vitro vascular calcification. Knockdown of Notch1 and Notch3 cooperatively increased expression of osteogenic transcriptional factors and decreased expression of SM22. Conclusion: Our results suggested that IS-induced VC is mediated through suppression of Notch activity in aortic SMCs, induction of osteogenic differentiation and apoptosis.