Cardiovascular Events in Hemodialysis Patients: Challenging against Vascular Calcification

Impact of Chronic Kidney Disease on Clinical Outcomes during Hospitalization and Five-Year Follow-Up after Coronary Artery Bypass Grafting

Background

Chronic kidney disease (CKD) is often associated with multiple comorbidities including diabetes mellitus, and each has its own complications and impact after cardiac surgery including coronary revascularization. The objective of this work was to study the impact of CKD on clinical outcomes after coronary artery bypass grafting (CABG) and to compare outcomes in patients with different grades of renal functions. We retrospectively reviewed all patients who underwent CABG from January 2016 to August 2020 at our tertiary care hospital using electronic medical records.

Results

The study included 410 patients with a median age of 60 years, and 28.6% of them had CKD and hospital mortality of 2.7%. About 71.4% of the patients had GFR > 60 mL/min per 1.73 m2, 18.1% had early CKD (GFR 30-60), 2.7% had late CKD (GFR < 30), and 7.8% of them had end-stage renal disease (ESRD) requiring dialysis. The CKD group had significantly more frequent hospital mortality (p = 0.04), acute cerebrovascular stroke (p = 0.03), acute kidney injury (AKI) (p < 0.001), longer ICU stay (p = 0.002), post-ICU stay (p = 0.001), and sternotomy wound debridement (p = 0.03) compared to the non-CKD group. The frequencies of new need for dialysis were 2.4% vs. 14.9% vs. 45.5% (p < 0.001) in the patients with GFR > 60 mL/min per 1.73 m2, early CKD, and late CKD, respectively. Acute cerebral stroke (OR: 10.29, 95% CI: 1.82-58.08, and p = 0.008), new need for dialysis (OR: 25.617, 95% CI: 13.78-85.47, and p < 0.001), and emergency surgery (OR: 3.1, 95% CI: 1.82-12.37, and p = 0.036) were the independent predictors of hospital mortality after CABG. The patients with CKD had an increased risk of strokes (HR: 2.14, 95% CI: 1.20-3.81, and p = 0.01) but insignificant mortality increase (HR: 1.44, 95% CI: 0.42-4.92, and p = 0.56) during follow-up.

Conclusion

The patients with CKD, especially the late grade, had worse postoperative early and late outcomes compared to non-CKD patients after CABG. Patients with dialysis-independent CKD had increased risks of needing dialysis, hospital mortality, and permanent dialysis after CABG.

Major cardiovascular events and associated factors among routine hemodialysis patients with end-stage renal disease at tertiary care hospital in Somalia

Introduction

Cardiovascular complications are the most significant cause of death in patients undergoing routine hemodialysi (HD) with end-stage renal disease (ESRD). The main objective of this study is to determine the significant cardiac events and risk factors in patients undergoing routine hemodialysis in Somalia.

Methods

We carried out a cross-sectional retrospective study in a single dialysis center in Somalia. Two hundred out of 224 were included. All of them had ESRD and were on hemodialysis during the study period between May and October 2021. The records of all patients were reviewed, and the following parameters were analyzed socio-demographic factors, risk factors for cardiovascular disease, and the presence of cardiovascular diseases.

Results

The mean age was 54 ± 17.5 years (range 18-88 years), and 106 (53%) patients were males. The prevalence of a cardiovascular disease among hemodialysis patients was 29.5%. Moreover, the distribution of cardiovascular diseases was different; heart failure was the most common, about 27.1%, followed by coronary artery disease (17%), pericarditis and pericardial-effusion (13.6%), dysrhythmia (10.2%), cerebrovascular-accident (8.5%), and peripheral vascular disease (3.4%). About 176 (88%) participants had at least one modifiable cardiovascular risk factor. The most common modifiable cardiovascular risk factor was hypertension (n = 45, 25.1%), followed by anemia (n = 28, 15.6%) and diabetes (n = 26, 14.5%). Younger (18-30) participants were six times less likely to have cardiovascular events among hemodialysis than older age 0.4 (0.11-1.12).

Conclusion

Low prevalence rate of cardiovascular complications was confirmed in ESRD patients receiving hemodialysis in the main HD center in Somalia. Diabetes, anemia, and hypertension were the highest significant risk factors for CVD in HD patients with ESRD in Somalia.

The Characteristics of Dialysis Membranes: Benefits of the AN69 Membrane in Hemodialysis Patients

Patients undergoing hemodialysis (HD) experience serious cardiovascular complications, through malnutrition, inflammation, and atherosclerosis. Amputation for peripheral arterial disease (PAD) is more prevalent in patients undergoing HD than in the general population. In addition, revascularization procedures in dialysis patients are often associated with subsequent amputation and high mortality rates. To improve the prognosis of dialysis patients, malnutrition and inflammation must be properly treated, which necessitates a better understanding of the characteristics of dialysis membranes. Herein, the characteristics of several dialysis membranes were studied, with a special reference to the AN69 membrane, noting several similarities to low-density lipoprotein (LDL)-apheresis, which is also applicable for the treatment of PAD. Both systems (LDL-apheresis and AN69) have anti-inflammatory and anti-thrombogenic effects because they use a negatively charged surface for extracorporeal adsorptive filtration from the blood/plasma, and contact phase activation. The concomitant use of both these therapeutic systems may have additive therapeutic benefits in HD patients. Here, we reviewed the characteristics of dialysis membranes and benefits of the AN69 membrane in dialysis patients.

Presepsin Level Correlates with the Development of Moderate Coronary Artery Calcifications in Hemodialysis Patients: A Preliminary Cross-Section Design Study

Purpose

End-stage renal disease patients have a high mortality rate linked to cardiovascular complications, and one of these complications is vascular calcification. This study was performed to test if presepsin, an inflammatory marker, is a predictor of coronary artery calcification (CAC) in hemodialysis (HD) patients.

Patients and Methods

This study was a cross-sectional design involving 48 HD patients and 13 control subjects. Coronary artery calcification score (CACs) was evaluated by a high resolution, ECG synchronized computed tomography of the heart using a CT calcium scoring. Presepsin and other laboratory analyses were performed on blood samples drawn before HD.

Results

Presepsin levels in HD patients were 14 times higher than healthy controls (P<0.01). Also, all laboratory tests except for vitamin D were significantly different than controls. Presepsin, phosphorus levels, and calcium-phosphate product were positively correlated with increasing CACs within groups of zero to moderate calcifications (p<0.05, R=0.459 and <0.01, R=0.591, respectively). These correlations were not seen with eGFR, PTH, calcium, vitamin D, CRP, or ESR levels. Furthermore, the log-transformed data of presepsin correlated with 1–15 months of HD vintage (p<0.05, R=0.482), whereas CACs data correlated with 1–20 months of HD vintage (p<0.05, R=0.425).

Conclusion

Although this study is preliminary and has a limited number of patients, it shows that presepsin, as an inflammatory marker, correlates with the development of moderate CAC in HD patients and may predict CAC development. Therefore, measuring presepsin and managing inflammation before and during the early phases of HD may lower coronary calcification development. However, more clinical studies in this direction are essential.

The Effects of Melatonin Supplementation on Parameters of Mental Health, Glycemic Control, Markers of Cardiometabolic Risk, and Oxidative Stress in Diabetic Hemodialysis Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

This study evaluated the effects of melatonin supplementation on parameters of mental health, glycemic control, markers of cardiometabolic risk, and oxidative stress in diabetic hemodialysis (HD) patients.

DESIGN

A randomized, double-blind, placebo-controlled clinical trial was conducted in 60 diabetic HD patients, 18-80 years of age. Participants were randomly divided into 2 groups to take either melatonin (2 x 5mg/day) (n = 30) or placebo (n = 30) 1 hour before bedtime for 12 weeks. The effects of melatonin on mental health, metabolic status, and gene expression related to metabolic status were assessed using multiple linear regression adjusting for age and BMI.

RESULTS

Melatonin supplementation significantly decreased Pittsburgh Sleep Quality Index (P = .007), Beck Depression Inventory index (P = .001), and Beck Anxiety Inventory index (P = .01) compared with the placebo. Additionally, melatonin administration significantly reduced fasting plasma glucose (β = -21.77 mg/dL, 95% CI -33.22 to -10.33, P < .001), serum insulin levels (β = -1.89 μIU/mL, 95% CI -3.34 to -0.45, P = .01), and homeostasis model of assessment-insulin resistance (β = -1.45, 95% CI -2.10 to -0.80, P < .001), and significantly increased the quantitative insulin sensitivity check index (β = 0.01, 95% CI 0.007-0.02, P < .001) compared with placebo treated subjects. In addition, melatonin administration resulted in a significant reduction in serum high sensitivity C-reactive protein (β = -1.92 mg/L, 95% CI -3.02 to -0.83, P = .001) and plasma malondialdehyde (β = -0.21 μmol/L, 95% CI -0.36 to -0.06, P = .005); also, significant rises in plasma total antioxidant capacity (β = 253.87 mmol/L, 95% CI 189.18-318.56, P < .001) and nitric oxide levels (β = 2.99 μmol/L, 95% CI 0.71-5.28, P = .01) were observed compared with the placebo.

CONCLUSION

Overall, melatonin supplementation for 12 weeks to diabetic HD patients had beneficial effects on mental health, glycemic control, inflammatory markers, and oxidative stress.

Long-Term Clinical and Angiographic Outcomes After Implantation of New-Generation Drug-Eluting Stents for Patients on Maintenance Hemodialysis

Prior research has revealed poorer clinical outcomes after drug-eluting stent (DES) implantation for hemodialysis patients. This study aims to investigate the long-term clinical and angiographic outcomes after new-generation DES implantation for hemodialysis patients.We retrospectively enrolled 91 consecutive patients (118 lesions) who underwent successful new-generation DES (everolimus-, zotarolimus-, and biolimus-eluting stents) implantation for the first time. We measured the serum calcium and phosphorus levels in the blood samples obtained just before hemodialysis. The follow-up period of clinical events was, at least, 1.5 years. In this study, major adverse cardiac and cerebrovascular events (MACCE) and clinically driven target lesion revascularization were reported in 36 (39.6%) and 11 (12.1%) patients, respectively. The prevalence of peripheral artery disease was significantly higher in the MACCE group (41.7% versus 14.5%, P = 0.006). The serum calcium level was significantly higher in the MACCE group (9.34 ± 0.92 mg/dL versus 8.77 ± 0.88 mg/dL; P = 0.004). The multivariate Cox proportional hazards model revealed that the serum calcium level (hazard ratio, 1.86; 95% confidence interval [CI]: 1.26-2.77; P = 0.002), suboptimal (over 55 mg²/dL²) calcium-phosphorus product (hazard ratio, 3.27; 95% CI: 1.41-7.61; P = 0.006) and the coexistence of peripheral artery disease (hazard ratio, 3.15; 95% CI: 1.49-6.65; P = 0.003) were independent predictors of MACCE.For hemodialysis patients, MACCE remains a frequent occurrence after new-generation DES implantation and is associated with calcium-phosphate metabolism and peripheral artery disease.

Fibroblast Growth Factor 21 Attenuates Vascular Calcification by Alleviating Endoplasmic Reticulum Stress Mediated Apoptosis in Rats

Fibroblast growth factor 21 (FGF21), a hormone with multiple metabolic properties, has proven to be pleiotropic biological effects and may play pivotal role in numerous cardiovascular and metabolic diseases in the future. Vascular calcification (VC) is a concomitant pathological process of various cardiovascular and metabolic diseases. However, the effects of FGF21 on VC remain unclear. Therefore, in this research, we aimed to explore the roles and mechanisms of FGF21 in VC induced by vitamin D₃ plus nicotine (VDN) treatment rats. After 28 days VDN treatment, the calcium overload was confirmed by blood pressure, ultrasound imaging, calcium content, ALP activity and aortic pathological characteristics. In terms of FGF21, exogenous FGF21 can ameliorate the elevation of blood pressure, aortic calcification and related injury in VC rats. To investigate the mechanisms of FGF21 on VC, the endoplasmic reticulum stress (ERS) mediated apoptosis pathways were tested. As a method to detect apoptosis, the increased positive TUNEL staining cells were alleviated by FGF21 treatment. Furthermore, exogenous FGF21 can suppress the increased ERS chaperone, GRP78, in the calcified aortas. In the three pathways of ERS mediated apoptosis, we found CHOP pathway and caspase-12 pathway were involved in the treatment of FGF21, but not p-JNK/JNK pathway. Our study proved for the first time that FGF21 can inhibit the progress of VC by alleviating ERS mediated apoptosis in rats. FGF21 might be a new target for preventing and treating VC.

Biochemical evidence of cell starvation in diabetic hemodialysis patients

Recently, the ratio of patients with diabetes mellitus (DM) among hemodialysis (HD) patients has increased to become the largest sub-population. Their prognoses are significantly worse than those of patients without diabetes (non-DM). In the present study, 10 DM patients who did not take meals and 10 non-DM patients who took meals during HD sessions were investigated. The time courses of the change in plasma levels of metabolites during HD were determined. DM patients exhibited decreased plasma levels of lactate, pyruvate and alanine and dramatically increased levels of ketone bodies. At the end of HD, the plasma levels of lactate, pyruvate, alanine and ketone body were 0.46 ± 0.07, 0.026 ± 0.01, 0.12 ± 0.04 and 0.26 ± 0.04 mM (mean ± standard error), respectively. The profile was ‘hypolactatemia and hyperketonemia’, indicating non-homeostasis. Glycolysis and tricarboxylic acid cycle were suppressed, and the oxidation of fatty acid was accelerated, indicating starvation, even though high amounts of glucose (150 mg/dl) in dialysate were supplied continuously to the bloodstream. In contrast, the plasma levels of lactate, pyruvate, and alanine in the non-DM patients were increased, with the levels of ketone body remaining low during HD to maintain homeostasis, indicating accelerated glycolysis. Furthermore, their plasma levels of insulin increased from 8.1 ± 1.4 to 19.8 ± 3.4 μU/ml, which indicated endogenous secretion stimulated by glucose in dialysate and meal intake. In contrast, in the DM patients, the levels decreased from 19.2 ± 3.4 to 5.5 ± 1.1 μU/ml. This value was the lower limit of the normal range. The depletion of the insulin through extracorporeal circulation may inhibit the transportation of glucose from the blood into the muscles, with the consequence of cell starvation. Such cell starvation along with lipolysis every two days may accelerate proteolysis and affect the prognosis of DM patients.

Coronary Artery Bypass Surgery in End-Stage Renal Disease Patients

The number of patients requiring hemodialysis is continuously increasing around the world. Hemodialysis affects patient quality of life and it is also associated with a higher risk for cardiovascular events. In addition to traditional risk factors for cardiovascular events such as hypertension, hyperlipidemia, and diabetes, hemodialysis is associated with hyperphosphatemia, chronic inflammation, vascular calcification, and anemia which accelerate atherosclerosis, vascular stiffness, and cardiac ischemia. Treatment strategy for coronary revascularization in this progressive disease remains controversial. However, a systematic treatment including medical therapy and complete revascularization through a less invasive strategy should be considered in addressing this problem. This review discusses the epidemiology, vascular pathology and current treatment options in patients with end-stage renal disease requiring coronary revascularization.