Cardiovascular Determinants of Mortality in Advanced Chronic Kidney Disease

Endothelial Function Assessment by Flow-Mediated Dilation Method: A Valuable Tool in the Evaluation of the Cardiovascular System

Cardiovascular diseases (CVDs) in the course of atherosclerosis are one of the most critical public health problems in the world. Endothelial cells synthesize numerous biologically active substances involved in regulating the functions of the cardiovascular system. Endothelial dysfunction is an essential element in the pathogenesis of atherosclerosis. Thus, the assessment of endothelial function in people without overt CVD allows for a more accurate estimate of the risk of developing CVD and cardiovascular events. The assessment of endothelial function is primarily used in scientific research, and to a lesser extent in clinical practice. Among the tools for assessing endothelial function, we can distinguish biochemical and physical methods, while physical methods can be divided into invasive and non-invasive methods. Flow-mediated dilation (FMD) is based on the ultrasound assessment of changes in the diameter of the brachial artery as a result of increased blood flow. FMD is a non-invasive, safe, and repeatable test, but it must be performed by qualified and experienced medical staff. The purpose of this paper is to present the literature review results on the assessment of endothelial function using the FMD method, including its methodology, applications in clinical practice and research, limitations, and future perspectives.

Coronary and extra-coronary artery calcium scores as predictors of cardiovascular events and mortality in chronic kidney disease stages 1-5: a prospective cohort study

BACKGROUND

Vascular calcification is a known risk factor for cardiovascular events and mortality in patients with chronic kidney disease (CKD). However, since there is a lack of studies examining several arterial regions at a time, we aimed to evaluate the risk of major adverse cardiovascular events (MACE) and all-cause mortality according to calcium scores in five major arterial sites.

METHODS

This was a prospective study of 580 patients from the Copenhagen CKD Cohort. Multidetector computed tomography of the coronary and carotid arteries, the thoracic aorta, the abdominal aorta, and the iliac arteries was used to determine vascular calcification at baseline. Calcium scores were divided into categories: 0, 1-100, 101-400, and > 400.

RESULTS

During the follow-up period of 4.1 years a total of 59 cardiovascular events and 64 all-cause deaths occurred. In Cox proportional hazards models adjusted for age, sex, eGFR, hypertension, diabetes mellitus, hypercholesterolemia, and smoking, only the coronary and carotid arteries, and the thoracic aorta were independent predictors of the designated endpoints. When examining the potential of calcification in the five arterial sites for predicting MACE, the difference in C-statistic was also most pronounced in these three sites, 0.21 (95% CI 0.16%-0.26%, P < 0.001), 0.26 (95% CI 0.22%-0.3%, P < 0.001), and 0.20 (95% CI 0.16%-0.24%, P < 0.001), respectively. This trend also applied to all-cause mortality.

CONCLUSIONS

The overall results, including data on specificity, suggest that calcium scores of the coronary and carotid arteries have the most potential for identifying patients with CKD at high cardiovascular risk and for evaluating new therapies.

Vascular Calcification in Chronic Kidney Disease: An Update and Perspective

Chronic kidney disease is a devastating condition resulting from irreversible loss of nephron numbers and function and leading to end-stage renal disease and mineral disorders. Vascular calcification, an ectopic deposition of calcium-phosphate salts in blood vessel walls and heart valves, is an independent risk factor of cardiovascular morbidity and mortality in chronic kidney disease. Moreover, aging and related metabolic disorders are essential risk factors for chronic kidney disease and vascular calcification. Marked progress has been recently made in understanding and treating vascular calcification in chronic kidney disease. However, there is a paucity of systematic reviews summarizing this progress, and investigating unresolved issues is warranted. In this systematic review, we aimed to overview the underlying mechanisms of vascular calcification in chronic kidney diseases and discuss the impact of chronic kidney disease on the pathophysiology of vascular calcification. Additionally, we summarized potential clinical diagnostic biomarkers and therapeutic applications for vascular calcification with chronic kidney disease. This review may offer new insights into the pathogenesis, diagnosis, and therapeutic intervention of vascular calcification.

Maximal Exercise Capacity in Chronic Kidney Disease Stage 4-5 Patients Transitioning to Renal Replacement Therapy or Continuing Conservative Care: A Longitudinal Follow-Up Study

INTRODUCTION

Chronic kidney disease (CKD) is associated with impaired maximal exercise capacity (MEC). However, data are scarce on the development of MEC in CKD stage 4-5 patients transitioning to renal replacement therapy (RRT).

METHODS

We explored the change in MEC measured in watts (Wlast4) with 2 consecutive maximal bicycle stress ergometry tests in 122 CKD stage 4-5 patients transitioning to dialysis and transplantation in an observational follow-up study.

RESULTS

Mean age was 58.9 ± 13.9 years and 43 (35.2%) were female. Mean time between the baseline and follow-up ergometry tests was 1,012 ± 327 days and 29 (23.8%) patients had not initiated RRT, 50 (41.0%) were undergoing dialysis, and 43 (35.2%) had received a kidney transplant at the time of the follow-up ergometry test. The mean Wlast4 was 91 ± 37 W and 84 ± 37 W for the baseline and follow-up ergometry tests, respectively (p < 0.001). The mean Wlast4 declined between the baseline and follow-up ergometry tests in patients not requiring RRT (p = 0.001) and transplant recipients (p = 0.005), but not in dialysis patients (p = 0.478). There were no differences in the ratio of Wlast4 of the follow-up to the baseline ergometry tests (∆Wlast4) between patients on different treatment modalities at the time of the follow-up test (p = 0.097). Mean capillary blood bicarbonate was significantly associated with ∆Wlast4 after adjusting for age and treatment modality in the multivariate linear regression analysis (β = 0.226, p = 0.012).

CONCLUSION

MEC declined or remained poor in advanced CKD patients transitioning to RRT or continuing conservative care in this observational study. Mean capillary blood bicarbonate was independently associated with the development of MEC.

Progression of Aortic Calcification in Stage 4-5 Chronic Kidney Disease Patients Transitioning to Dialysis and Transplantation

BACKGROUND AND AIMS

Abdominal aortic calcification (AAC) is common in chronic kidney disease (CKD) patients and associated with increased mortality. Comparative data on the AAC score progression in CKD patients transitioning from conservative treatment to different modalities of renal replacement therapy (RRT) are lacking and were examined.

METHODS

150 study patients underwent lateral lumbar radiograph to study AAC in the beginning of the study before commencing RRT (AAC1) and at 3 years of follow-up (AAC2). We examined the associations between repeated laboratory tests taken every 3 months, echocardiographic and clinical variables and AAC increment per year (ΔAAC), and the association between ΔAAC and outcomes during follow-up.

RESULTS

At the time of AAC2 measurement, 39 patients were on hemodialysis, 39 on peritoneal dialysis, 39 had a transplant, and 33 were on conservative treatment. Median AAC1 was 4.8 (0.5-9.0) and median AAC2 8.0 (1.5-12.0) (p < 0.0001). ΔAAC was similar across the treatment groups (p = 0.19). ΔAAC was independently associated with mean left ventricular mass index (LVMI) (log LVMI: β = 0.97, p = 0.02) and mean phosphorus through follow-up (log phosphorus: β = 1.19, p = 0.02) in the multivariable model. Time to transplantation was associated with ΔAAC in transplant recipients (per month on the waiting list: β = 0.04, p = 0.001). ΔAAC was associated with mortality (HR 1.427, 95% confidence interval 1.044-1.950, p = 0.03).

CONCLUSION

AAC progresses rapidly in patients with CKD, and ΔAAC is similar across the CKD treatment groups including transplant recipients. The increment rate is associated with mortality and in transplant recipients with the time on the transplant waiting list.

Dental health assessed using panoramic radiograph and adverse events in chronic kidney disease stage 4-5 patients transitioning to dialysis and transplantation-A prospective cohort study

Background and aims

Oral health could potentially be a modifiable risk factor for adverse outcomes in chronic kidney disease (CKD) patients transitioning from predialysis treatment to maintenance dialysis and transplantation. We aimed to study the association between an index of radiographically assessed oral health, Panoramic Tomographic Index (PTI), and cardiovascular and all-cause mortality, major adverse cardiovascular events (MACEs) and episodes of bacteremia and laboratory measurements during a three-year prospective follow-up in CKD stage 4–5 patients not on maintenance dialysis at baseline.

Methods

Altogether 190 CKD stage 4–5 patients without maintenance dialysis attended panoramic dental radiographs in the beginning of the study. The patients were followed up for three years or until death. MACEs and episodes of bacteremia were recorded during follow-up. Laboratory sampling for C-reactive protein and leukocytes was repeated tri-monthly.

Results

PTI was not associated with baseline laboratory parameters or C-reactive protein or leukocytes examined as repeated measures through the 3-year follow-up. During follow-up, 22 patients had at least one episode of bacteremia, but only 2 of the bacteremias were considered to be of oral origin. PTI was not associated with incident bacteremia during follow-up. Thirty-six patients died during follow-up including 17 patients due to cardiovascular causes. During follow-up 42 patients were observed with a MACE. PTI was independently associated with all-cause (HR 1.074 95% CI 1.029–1.122, p = 0.001) and cardiovascular (HR 1.105, 95% CI 1.057–1.157, p<0.0001) mortality, as well as, incident MACEs (HR 1.071 95% CI 1.031–1.113, p = 0.0004) in the multivariable Cox models adjusted for age and kidney transplantation or CKD treatment modality during follow-up.

Conclusions

Radiographically assessed dental health is independently associated with all-cause and cardiovascular mortality and MACEs but not with the incidence of bacteremia in CKD stage 4–5 patients transitioning to maintenance dialysis and renal transplantation during follow-up.