Association of mineral content outside of bone with coronary artery calcium and 1-year cardiovascular prognosis in maintenance hemodialysis patients

Feasibility analysis of non-electrocardiogram-triggered chest low-dose computed tomography using a kV-independent reconstruction algorithm for predicting cardiovascular disease risk in patients receiving maintenance hemodialysis

OBJECTIVES

This study aimed to evaluate the feasibility and accuracy of non-electrocardiogram (ECG)-triggered chest low-dose computed tomography (LDCT) with a kV-independent reconstruction algorithm in assessing coronary artery calcification (CAC) degree and cardiovascular disease risk in patients receiving maintenance hemodialysis (MHD).

METHODS

In total, 181 patients receiving MHD who needed chest CT and coronary artery calcium score (CACS) scannings sequentially underwent non-ECG-triggered, automated tube voltage selection, high-pitch chest LDCT with a kV-independent reconstruction algorithm and ECG-triggered standard CACS scannings. Then, the image quality, radiation doses, Agatston scores (ASs), and cardiac risk classifications of the two scans were compared.

RESULTS

Of the 181 patients, 89, 83, and 9 were scanned at 100, 110, and 120 kV, respectively. Excluding those scanned at 120 kV, 172 patients were enrolled. Although the ASs of non-ECG-triggered LDCT were lower than those of the standard CACS, the agreement and correlation of ASs of the two scans were excellent, and both intraclass correlation coefficients (ICCs) and Pearson's correlation coefficients were > 0.96. Cardiac risk classifications did not significantly differ between the non-ECG-triggered LDCT and standard CACS (χ2 = 3.933, P = 0.269), and the agreement was excellent (weighted kappa value = 0.936; 95% confidence interval (CI): 0.903-0.970). The effective radiation doses of standard CACS and non-ECG-triggered chest LDCT scannings were 1.34 ± 0.74 and 1.04 ± 0.35 mSv, respectively.

CONCLUSIONS

The non-ECG-triggered, automated tube voltage selection, high-pitch chest LDCT protocol with a kV-independent reconstruction algorithm can obtain chest scans and ASs simultaneously and significantly reduce patients' radiation exposure.

Factors associated with readmission in chronic kidney disease: Systematic review and meta-analysis

BACKGROUND

Risk factors associated with all-cause hospital readmission are poorly characterised in patients with chronic kidney disease.

OBJECTIVE

A systematic review and meta-analysis were conducted to identify risk factors and protectors of hospital readmission in chronic kidney disease.

DESIGN, PARTICIPANTS & MEASUREMENTS

Studies involving adult patients were identified from four databases from inception to 31/03/2020. Random-effects meta-analyses were conducted to determine factors associated with all-cause 30-day hospital readmission in general chronic kidney disease, in dialysis and in kidney transplant recipient groups.

RESULTS

Eighty relevant studies (chronic kidney disease, n = 14 studies; dialysis, n = 34 studies; and transplant, n = 32 studies) were identified. Meta-analysis revealed that in both chronic kidney disease and transplant groups, increasing age in years and days spent at the hospital during the initial stay were associated with a higher risk of 30-day readmission. Other risk factors identified included increasing body mass index (kg/m2 ) in the transplant group, and functional impairment and discharge destination in the dialysis group. Within the chronic kidney disease ​​​​group, having an outpatient follow-up appointment with a nephrologist within 14 days of discharge was protective against readmission but this was not protective if provided by a primary care provider or a cardiologist.

CONCLUSION

Risk-reduction interventions that can be implemented include a nephrologist appointment within 14 days of hospital discharge, rehabilitation programme for functional improvement in the dialysis group and meal plans in the transplant group. Future risk analysis should focus on modifiable factors to ensure that strategies can be tested and implemented in those who are more at risk.

Regulatory effects of nutritional and metabolic disorders on vascular calcification in chronic kidney disease: a narrative review

Background and Objective

Vascular calcification (VC) is common in chronic kidney disease (CKD) patients and is associated with poor cardiovascular outcomes. This study aims to review nutritive pro-calcifying factors of CKD.

Methods

Electronic databases (PubMed, Embase, and the Cochrane Central Register of Controlled Trials) were searched from 2001 as at July 26, 2022, to select and summarize the basic and clinical studies reporting the effects of malnutrition or metabolic disorders on VC in CKD and the evolving treatments for these nutrient metabolic disorders.

Key Content and Findings

Hyperphosphatemia, calcium load, hypomagnesemia, iron deficiency, lipoprotein(a) abnormalities, protein malnutrition, and vitamin K deficiency secondary to CKD were closely associated with the occurrence and development of VC. Elevated phosphate and calcium levels were essential contributors to VC, yet current phosphate binders with good phosphate-lowering effects had not been shown to delay VC progression in CKD, and it remained challenging on how to identify and prevent calcium overload. Magnesium supplementation was the most promising treatment for mitigating VC, as supported by in vitro and in vivo studies and clinical trials. Correction of iron and vitamin K deficiency might contribute to VC attenuation, yet there was a lack of clinical evidence on CKD patients.

Conclusions

This review highlighted the effects of nutrient metabolism disorders on CKD-VC, and additional studies are needed to further address optimal nutrition strategies for mitigating VC in CKD.

Vascular Calcification Exacerbates Abnormal Blood Pressure Variability in Chronic Kidney Disease: A "Two-Step" Study in Rats

INTRODUCTION

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD) with poor cardiovascular prognosis. The aim of this study was to explore the impact of VC on blood pressure variability (BPV) in animal models of CKD.

METHODS

Two optimal modelling methods, adenine high-phosphorus (HP) diet + calcitriol and 5/6 nephrectomy (Nx) + HP diet + calcitriol, for CKD-VC were chosen from the first-step experiment for the next step. A total of 36 male Wistar rats were randomly assigned to the standard-chow, sham-operated, adenine, 5/6Nx, adenine-VC, and 5/6Nx-VC groups. Continuous blood pressure (BP) measurement using the BP-2000 animal noninvasive BP analyser was started at the 9th week for the standard-chow, adenine, and adenine-VC groups and at the 7th week for the sham-operated, 5/6Nx, and 5/6Nx-VC groups. BPV metrics (BPVs), including the difference between maximum and minimum values, standard deviation, coefficient of variation, average real variability, and residuals derived from the generalized linear model of BP, were calculated.

RESULTS

The first experiment showed that the use of calcitriol accelerated the progression of VC in CKD rats (the modelling period was shortened from 16 weeks to 4-8 weeks) and confirmed the occurrence of VC at weeks 8 and 6 in the adenine-VC and 5/6Nx-VC groups, respectively. In the second experiment, 13 of 20 hour-to-hour BPVs increased significantly with the development of CKD and VC. BPV differences among the standard-chow, adenine, and adenine-VC groups were mainly due to the differences between the standard-chow and adenine-VC groups (7 of 10 BPVs were significantly different), followed by the differences between the standard-chow and adenine groups (3 of 10). BPV differences among the sham-operated, 5/6Nx, and 5/6Nx-VC groups were caused by the differences between the 5/6Nx-VC and 5/6Nx groups (4 of 10) or the 5/6Nx-VC and sham-operated groups (3 of 10).

CONCLUSION

An increased BPV is observed in CKD rats, and VC further aggravates the abnormality of BPVs independent of CKD.

The predictive value of coronary artery calcification score combined with bone mineral density for the 2-year risk of cardiovascular events in maintenance hemodialysis patients

PURPOSE

Cardiovascular disease is the leading cause of death in maintenance hemodialysis (MHD) patients. The aim of this study is to investigate the predictive value of coronary artery calcification score (CACs) combined with bone mineral density (BMD) for the risk of cardiovascular diseases in MHD patients.

METHODS

From January 2017 to January 2019, we enrolled 112 MHD patients and 112 controls in Ningbo First Hospital, and retrospectively counted the cardiovascular events in the next 2 years after enrollment. According to the occurrence of cardiovascular events, the MHD patients were divided into CVD group and non-CVD group. The differences of vertebral BMD and CACs between the two groups were compared. ROC curve, Kaplan-Meier curve and Cox regression analyses were used for assess the predictive value of 2-year cardiovascular events in MHD patients.

RESULTS

Among 112 MHD patients, 49 (43.75%) patients had cardiovascular events. The results showed that the average value of BMD in MHD patients was significantly lower than that in the control group (99.88 ± 30.99 VS. 108.35 ± 23.98, P = 0.0231). The CACs in MHD patients were significantly higher than that in the control group (317.81 ± 211.53 VS. 190.03 ± 100.50, P < 0.001). The results between CVD group and the non-CVD group were to the same direction (BMD: 81.12 ± 31.28 VS. 114.48 ± 21.61, P < 0.001; CACs: 447.16 ± 234.11 VS. 217.21 ± 119.03, P < 0.001). Besides, CACs combined with BMD yield an AUC of 0.875 with a sensitivity of 79.60%, a specificity of 82.50%. Kaplan-Meier curve and Cox regression analyses indicated that CACs and BMD were independently associated with high risk of cardiovascular events in MHD patients.

CONCLUSION

The combination of CACs and vertebral BMD could predict the occurrence of cardiovascular events in MHD patients to some extent.

Visceral Fat Area Is a Better Predictor Than Coronary Artery Calcification Score for Cardiovascular Outcomes and All-Cause Death in Patients on Hemodialysis

OBJECTIVES

The aim of this study is to compare the prognostic effects of visceral fat area (VFA) with coronary artery calcification score (CACs) in patients on maintenance hemodialysis.

DESIGN AND METHODS

In the prospective study with no intervention, clinical characteristics and serum biochemical indexes at baseline for each patient were collected through the electronic medical records. Body composition assessment using bioelectrical impedance analysis, computed tomography examination with the Agatston scoring method, and echocardiographic measurements were performed at enrollment. Primary endpoints included cardiovascular events (CVEs), cardiovascular death (CVD), and all-cause death.

RESULTS

A total of 97 Chinese patients aged 48 (35-62) years were enrolled from our Hemodialysis Center, of which 61.9% were male and 20.6% had diabetes. The median of VFA and CACs at baseline was 64.5 (43.5-88.7) cm² and 0.9 (0-467.6), respectively. CVEs occurred in 20 (20.6%) patients during a median follow-up of 26.4 (13-27.7) months. The cardiovascular and all-cause mortality was 8.2% (8 patients) and 11.3% (11 patients), respectively. VFA was associated with CVEs (hazard ratio [HR] = 9.21 for VFA ≥71.3 cm² vs. VFA <71.3 cm², P = .017), CVD (HR = 1.11 for 1 cm² increase, P = .035), and all-cause mortality (HR = 1.08 for 1 cm² increase, P = .011). Also, VFA was significantly correlated with cardiac structure parameters and the development of left ventricular hypertrophy (odds ratio = 1.02 for 1 cm² increase, P = .03). Yet, CACs were not correlated with CVEs, CVD, or all-cause mortality.

CONCLUSIONS

Increased VFA can be used as an independent predictor for CVEs, CVD, and all-cause mortality. The effect VFA exerts on cardiac reconstruction might be the underlying mechanism. Further studies are warranted for the management of VFA in the hemodialysis population.

Association of mineral content outside of bone with coronary artery calcium and 1-year cardiovascular prognosis in maintenance hemodialysis patients

Coronary artery calcifications (CACs) are common among maintenance hemodialysis (MHD) patients and associated with increased morbidity and mortality due to cardiovascular events. The insight into chronic kidney disease‐mineral and bone disorder (CKD‐MBD) established a correlation between dysregulated mineral metabolism and CACs. This study aimed to identify the association of mineral content outside of bone (MCOB) with CACs and cardiovascular events in MHD patients. In the pilot prospective study with no intervention, patients underwent body composition assessment by body composition monitor after hemodialysis and computed tomography examination using the Agatston scoring method simultaneously within a week. The primary end point included cardiovascular events and cardiovascular death. Correlations and receiver operating characteristic analysis elucidated the associations of MCOB with CACs; multivariate analysis assessed the cardiovascular risk for groups with different MCOB. One hundred three eligible patients with an average age of 48 (35‐63) years old were enrolled and followed up to 12 (11‐12.5) months, among which 52.4% had detectable CACs at baseline. MCOB showed an inverse correlation with Agatston score and significantly discriminated the patients with Agatston score > 0 (AUC = 0.737; P < 0.001) and 400 (AUC = 0.733; P < 0.001). MCOB ≤ 9.2657 mg/kg was an independent risk factor for CACs (OR = 4.853; P = 0.044) and strong predictor for cardiovascular morbidity and mortality (HR = 10.108; P = 0.042), as well as rehospitalization (HR = 2.689; P = 0.004). MCOB inversely correlated with the presence and extent of CACs, and could discriminate Agatston score > 0 and 400, which also presented as an independent indicator for CKD‐MBD and 1‐year cardiovascular prognosis in adult MHD patients. Additional studies are required for identifying this issue.