Luminita Voroneanu

Vascular calcification in chronic kidney disease.

VC (vascular calcification) is highly prevalent in patients with CKD (chronic kidney disease), but its mechanism is multifactorial and incompletely understood. In addition to increased traditional risk factors, CKD patients also have a number of non-traditional cardiovascular risk factors, which may play a prominent role in the pathogenesis of arterial calcification, such as duration of dialysis and disorders of mineral metabolism. The transformation of vascular smooth muscle cells into chondrocytes or osteoblast-like cells seems to be a key element in VC pathogenesis, in the context of passive calcium and phosphate deposition due to abnormal bone metabolism and impaired renal excretion. The process may be favoured by the low levels of circulating and locally produced VC inhibitors. VC determines increased arterial stiffness, left ventricular hypertrophy, a decrease in coronary artery perfusion, myocardial ischaemia and increased cardiovascular morbidity and mortality. Although current therapeutic strategies focus on the correction of phosphate, calcium, parathyroid hormone or vitamin D, a better understanding of the mechanisms of abnormal tissue calcification may lead to development of new therapeutic agents, which could reduce VC and improve cardiovascular outcome in CKD patients. The present review summarizes the following aspects: (i) the pathophysiological mechanism responsible for VC and its promoters and inhibitors, (ii) the methods for detection of VC in patients with CKD, including evaluation of arterial stiffness, and (iii) the management of VC in CKD patients.

Lipids, blood pressure and kidney update 2014.

This paper is an effort to review all the most important studies and guidelines in the topics of lipid, blood pressure and kidney published in 2014. Irrespective of advances, the options for improving simultaneous hypercholesterolemia and hypertension management (as well as its complication - chronic kidney disease) remain a problem. Recommending hypolidemic, hypotensive and kidney disease drugs to obtain therapy targets in cardiovascular, diabetic, elderly and kidney disease (=high risk) patients might strengthen risk factor control, improve compliance and the therapy efficacy, and in the consequence reduce the risk of cardiovascular events and mortality rate. That is why the authors have decided to summary and discuss the recent scientific achievements in the field of lipid, blood pressure and kidney.

Predicting mortality in haemodialysis patients: a comparison between lung ultrasonography, bioimpedance data and echocardiography parameters

BACKGROUND The use of lung ultrasonography to evaluate extravascular lung water and its consequences has received growing attention in different clinical areas, including, in recent years, end-stage renal disease patients treated by haemodialysis (HD). Lung congestion is a direct consequence of either overall overhydration and/or cardiac dysfunction, but the exact contribution of each of these tests to mortality is unknown. METHODS In this prospective observational study, we enrolled 96 patients from a single HD unit undergoing thrice weekly HD. We used three different methods of evaluation: lung ultrasonography (pre- and post-dialysis), bioimpedance spectroscopy (pre- and post-dialysis) and echocardiography (pre-dialysis). The objective of the study was to test for the first time the prognostic value of ultrasound lung comets (ULC) combined with bioimpedance-derived data [total body water (TBW), extravascular water, hydration status-ΔHS] and several echocardiographic parameters. Mortality was analysed after a median of 405.5-day follow-up. RESULTS Pre-dialysis lung congestion was classified as moderate (ULC = 16-30) in 19.8% of the patients and severe in 12.5% of patients (ULC > 30), while only 19.8% appear to be hyperhydrated (ΔHS > 15%). The pre-dialysis ultrasound lung congestion score correlated significantly with all of the bioimpedance-derived parameters. In a multivariate Cox model that included ULC score, demographic, ecocardiographic and bioimpedance parameters, the factors that remained significantly associated with survival time were the pre-dialysis ULC score and left ventricular mass index. The pre-HD ULC score has a significant discriminating power for survival, while the bioimpedance-derived hydration status has no discriminatory abilities in terms of survival. CONCLUSIONS To our knowledge, this study is the first one that compares three different strategies to predict mortality in haemodialysed patients. The lung comet score emerged as the best predictor for the relationship hydration status-mortality, independently of bioimpedance-derived parameters in this population.

The Effects of Vitamin D Therapy on Left Ventricular Structure and Function - Are These the Underlying Explanations for Improved CKD Patient Survival?

Cardiovascular disease is a major cause of death among patients with chronic kidney disease and vitamin D deficiency is a common problem also among these patients. Abnormalities in left ventricular size and function are frequent, as they are encountered in 70–80% of incident dialysis patients. These alterations develop early in the course of renal disease and their prevalence progresses in parallel with the decline in renal function. This process of left ventricular dilatation with compensatory hypertrophy continues after the institution of dialysis therapy, especially in the first year. The main factors responsible for the progression of left ventricular hypertrophy (LVH) are considered to be blood pressure and anemia, and in patients receiving hemodialysis, the arteriovenous fistula, volume overload and abnormalities in mineral metabolism. This additional potential set of factors related to LVH – mineral and bone metabolism – is intriguing and begs an immediate question: by what possible mechanism can these factors be linked to cardiac morphology? Recent observational studies have indeed indicated that vitamin D treatment was associated with a significant reduction of cardiovascular death among dialysis patients, and a reduction in LVH; in contrast, other studies suggested that excess vitamin D contributes to risk of hypercalcemia and vascular calcification, which is associated with reduced survival and morbidity. This review examines the evidence linking vitamin D with cardiac structure and function.

Methods and potential biomarkers for the evaluation of endothelial dysfunction in chronic kidney disease: A critical approach

The impressive cardiovascular morbidity and mortality of chronic kidney disease (CKD) patients is attributable in a significant proportion to endothelial dysfunction (ED), arterial stiffness, and vascular calcifications. Abnormal vascular reactivity in these patients is more pronounced compared with other high-risk populations, but remains undiagnosed in the usual clinical setting. We briefly review the most important causes and risk factors of ED, oxidative stress, and inflammation related to arterial stiffness. We describe the main methods of ED investigation and the importance of using potential biomarkers together with classic techniques for a more comprehensive assessment of this condition. These methods include evaluation of: forearm blood flow by plethysmography, skin microcirculation by laser Doppler, and flow-mediated vasodilation by Doppler ultrasound imaging. Applanation tonometry is an easy-to-handle tool that allows a clinically reliable assessment of arterial stiffness and is also useful in quantifying endothelium-dependent and -independent vascular reactivity. We also discuss the diagnostic and therapeutic impact of new markers of ED in the CKD population. Improvement of endothelial function is an important challenge for clinical practice, and there are relatively few therapeutical strategies available. Therefore, a combined biomarker and bedside investigational approach could be a starting point for developing optimal therapeutic tools.

Overhydration, Cardiac Function and Survival in Hemodialysis Patients

Background and objectives Chronic subclinical volume overload occurs very frequently and may be ubiquitous in hemodialysis (HD) patients receiving the standard thrice-weekly treatment. It is directly associated with hypertension, increased arterial stiffness, left ventricular hipertrophy, heart failure, and eventually, higher mortality and morbidity. We aimed to assess for the first time if the relationship between bioimpedance assessed overhydration and survival is maintained when adjustments for echocardiographic parameters are considered. Design, setting, participants and measurements A prospective cohort trial was conducted to investigate the impact of overhydration on all cause mortality and cardiovascular events (CVE), by using a previously reported cut-off value for overhydration and also investigating a new cut-off value derived from our analysis of this specific cohort. The body composition of 221 HD patients from a single center was assessed at baseline using bioimpedance. In 157 patients supplemental echocardiography was performed (echocardiography subgroup). Comparative survival analysis was performed using two cut-off points for relative fluid overload (RFO): 15% and 17.4% (a value determined by statistical analysis to have the best predictive value for mortality in our cohort). Results In the entire study population, patients considered overhydrated (using both cut-offs) had a significant increased risk for all-cause mortality in both univariate (HR = 2.12, 95%CI = 1.30–3.47 for RFO>15% and HR = 2.86, 95%CI = 1.72–4.78 for RFO>17.4%, respectively) and multivariate (HR = 1.87, 95%CI = 1.12–3.13 for RFO>15% and HR = 2.72, 95%CI = 1.60–4.63 for RFO>17.4%, respectively) Cox survival analysis. In the echocardiography subgroup, only the 17.4% cut-off remained associated with the outcome after adjustment for different echocardiographic parameters in the multivariate survival analysis. The number of CVE was significantly higher in overhydrated patients in both univariate (HR = 2.46, 95%CI = 1.56–3.87 for RFO >15% and HR = 3.67, 95%CI = 2.29–5.89 for RFO >17.4%) and multivariate (HR = 2.31, 95%CI = 1.42–3.77 for RFO >15% and HR = 4.17, 95%CI = 2.48–7.02 for RFO >17.4%) Cox regression analysis. Conclusions The study shows that the hydration status is associated with the mortality risk in a HD population, independently of cardiac morphology and function. We also describe and propose a new cut-off for RFO, in order to better define the relationship between overhydration and mortality risk. Further studies are needed to properly validate this new cut-off in other HD populations.

Silymarin in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Type 2 diabetes mellitus (T2DM) is associated with increased risk of cardiovascular disease and nephropathy—now the leading cause of end-stage renal disease and dialysis in Europe and the United States. Inflammation and oxidative stress play a pivotal role in the development of diabetic complications. Silymarin, an herbal drug with antioxidant and anti-inflammatory properties, may improve glycemic control and prevent the progression of the complications. In a systematic review and meta-analysis including five randomized controlled trials and 270 patients, routine silymarin administration determines a significant reduction in fasting blood glucose levels (−26.86 mg/dL; 95% CI −35.42–18.30) and HbA1c levels (−1.07; 95% CI −1.73–0.40) and has no effect on lipid profile. Benefits for silymarin on proteinuria and CKD progressions are reported in only one small study and are uncertain. However, being aware of the low quality of the available evidence and elevated heterogeneity of these studies, no recommendation can be made and further studies are needed.

Predictive Value for Galectin 3 and Cardiotrophin 1 in Hemodialysis Patients

Patients with end-stage renal disease (ESRD) have an increased risk of all-cause mortality. The prognostic value of the new cardiac biomarkers, cardiotrophin 1 (CT-1) and galectin 3 (GAL-3), has not yet been defined in hemodialysis (HD) patients. The aim of this study was to determine the use of these novel biomarkers for predicting mortality in HD patients. Plasma GAL-3 and CT-1 concentrations were determined (at baseline) in 88 HD patients followed for 22.2 ± 4.7 months. During the follow-up period, 21 (23.9%) deaths were recorded. According to Cox analysis, the cutoff point for GAL-3 as a predictor of mortality was 23.73 ng/mL, while the cutoff point for CT-1 as a predictor of mortality was 36 pg/mL. In univariate analysis, only GAL-3 >23.73 ng/mL was an independent predictor of mortality (hazard ratio 2.60; 95% confidence interval, 1.09-6.18). In a multivariable Cox proportional hazards model, GAL-3 levels above the cutoff value remained an independent predictor of all-cause mortality. Our data suggest that similar to the general population, GAL-3 is an independent predictor of mortality in HD patients.

Superior predictive value for NTproBNP compared with high sensitivity cTnT in dialysis patients: a pilot prospective observational study.

Background/Aims: The clinical utility of the new biomarker, high sensitivity cardiac T troponin (hs-cTnT) is still unclear in dialysis patients. Furthermore, the prognostic value of combining N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and hs-cTnT has not been explored so far. The objective of this pilot study was to determine the utility of hs-cTnT alone versus hs-cTnT in combination with NT-proBNP for predicting death in a stable hemodialysis cohort. Methods: A prospective observational pilot study including 98 chronic asymptomatic hemodialysis patients with a follow up period of 24 months was designed. The cut-off values for NT-proBNP and hs-cTnT were calculated using receiver operating characteristic (ROC) analysis, using mortality as an end-point. Based on the cut-off values, the cohort was divided into four groups. Group 1 - NT-proBNP < 14275 pg/ml and hs-cTnT < 69.48 ng/l; group 2 - NT-proBNP < 14275 pg/ml and hs-cTnT > 69.48 ng/l; group 3 - NT-proBNP > 14275 pg/ml and hs-cTnT < 69.48 ng/l; group 4 - NT-proBNP > 14275 pg/ml and hs-cTnT > 69.48 ng/l. Survival for each group was determined using the Kaplan-Meier method and Cox regression analysis. Results: During the follow-up period 16 patients died. According to the ROC curves analysis, the cut-off point for hs-cTnT and for NT-proBNP were 69.43 ng/l (AUC = 0.618; p = 0.04) and 14275 pg/ml (AUC = 0.722; p = 0.003), respectively. In univariate Cox analysis, both hs-cTnT (HR = 3.34; p = 0.016) and NT-proBNP (HR = 5.94; p = 0.01) were predictors of death. In the multivariable Cox proportional hazards model, only NT-pro-BNP levels above the cut-off value remained an independent predictor of all-cause mortality. The combined elevation of both biomarkers did not improve significantly the prognostic value compared with NT-proBNP alone (HR = 6.15 versus HR =4 .78; p = 0.338). Conclusion: NT-pro-BNP is a strong predictor of overall mortality in asymptomatic hemodialysis patients. The addition of hs-cTnT did not improve the prognostic accuracy compared with NT proBNP alone.

Routine Bioimpedance-Derived Volume Assessment for All Hypertensives: A New Paradigm

Hypertension is one of the most common worldwide diseases. Is linked with increased morbidity and mortality and amplified costs to society; in this context, preventing and treating hypertension is an imperative public health challenge. Unidentified, clinically unapparent volume expansion is an important cause for hypertension. Optimization of fluid status was associated with an improvement in BP control, a substantial regression of the left ventricular mass index, arterial stiffness and better survival rate in several cohorts. Clinical assessment of hydration status is an inaccurate clinical science. Bioimpedance provides a noninvasive and reliable, simple, reproducible technology for diagnosing subclinical fluid accumulation. Several small studies and a recent meta-analysis performed in patients with resistant hypertension reported an improved BP control in the impedance treated group compared with the group of patients treated as per clinical judgment alone. A combined approach (using both sphygmomanometers and bioimpedance) and individualized antihypertensive treatment in hypertensives patients it seems probable to improve BP control and possibly end organ damage. i 2014 S. Karger AG, Basel