Coronary artery disease in end-stage renal disease: no longer a simple plumbing problem

Effect of platelet indices on mortality and comorbidity in peritoneal dialysis: a cohort study

BACKGROUND

There were limited data investigating platelet indices in predicting peritoneal dialysis (PD) outcomes on comorbidities. The aim of this study was to evaluate the association between platelet indices and new-onset comorbidity and all-cause mortality in PD patients.

METHODS

A single-center, retrospective observational cohort study was conducted in incident PD patients from 28 December 2011 to 24 January 2018, and followed up until 31 December 2022. Time to the first new-onset cardiovascular disease (CVD) and time to the first new-onset infection event after PD were identified as the primary outcomes. All-cause mortality was identified as the secondary endpoint. The correlation between platelet indices and comorbidities and all-cause mortality were assessed by Cox model. Data of liver disease status was not collected and analyzed. Survival curves were performed by Kaplan-Meier method with log-rank tests.

RESULTS

A total of 250 incident PD patients with a median follow-up of 6.79 (inter-quarter range 4.05, 8.89) years was included. A total of 81 and 139 patients experienced the first new-onset CVD and infection event respectively during the follow-up period. High mean platelet volume (MPV) was independently associated with high risk of time to the first new-onset CVD (HR 1.895, 95% CI 1.174-3.058, p = 0.009) and all-cause mortality (HR 1.710, 95% CI 1.155-2.531, p = 0.007). Patients with low mean platelet volume to platelet count ratio (MPV/PC) were prone to occur the new-onset infection events (log rank 5.693, p = 0.017). Low MPV/PC (HR 0.652, 95% CI 0.459-0.924, p = 0.016) was significantly associated with the time to the first new-onset infection event on PD.

CONCLUSIONS

Platelet indices were associated with the new-onset CVD, infectious comorbidities and all-cause mortality on PD. Low MPV/PC was associated with time to the first new-onset infection event in PD patients. Moreover, high MPV was associated with new-onset CVD and all-cause mortality in the incident PD patients.

In-hospital outcomes of PCI in patients who have ESRD vs non-ESRD patients, a retrospective study involving a National Inpatient Sample (NIS) database

BACKGROUND

Cardiovascular disease is the leading cause of death for patients with end-stage renal disease (ESRD). ESRD is known to affect a large portion of the American population. Previous data for patients undergoing percutaneous coronary intervention (PCI) in the setting of ESRD for Acute Coronary Syndrome (ACS) and non-ACS etiologies have shown to have an increase in in-hospital mortality, and prolonged hospitalization among other complications.

METHODS

The national inpatient sample (NIS) was used to identify patients who underwent PCI between the years 2016-2019. Patients were then grouped into those with ESRD on renal replacement therapy (RRT). Logistic regression models were employed to assess the primary outcome of in-hospital mortality, while linear regression models were utilized to evaluate secondary outcomes, including hospitalization cost and length of stay.

RESULTS

A total of 21,366 unweighted observations were initially included, consisting of 50 % ESRD patients and 50 % randomly selected patients without ESRD who underwent PCI. These observations were weighted to represent a national estimate of 106,830 patients. The mean age of the study population was 65 years, and 63 % of the patients were male. The ESRD group had a greater representation of minority groups compared to the control group. The in-hospital mortality rate was significantly higher in the ESRD group compared to the control group, with an odds ratio of 1.803 (95 % CI: 1.502 to 2.164; p-value of 0.0002). Additionally, the ESRD group had significantly higher healthcare costs and longer length of stay, with a mean difference of $47,618 (95 % CI: $42,701 to $52,534, p-value <0.0001) and 2.933 days (95 % CI, 2.729 to 3.138 days, p-value <0.0001), respectively.

CONCLUSION

In-hospital mortality, cost, and length of stay for patients undergoing PCI were found to be significantly greater in the ESRD group.

Long-term outcomes after stent implantation in very small vessel coronary artery disease

BACKGROUND

Percutaneous coronary interventions (PCI) in very small vessel lesions represent an intriguing aspect of coronary artery disease (CAD). Uncertainty still exists in stent implantation in very small caliber vessels. This study aimed to evaluate the long-term outcomes of patients treated with 2.0-mm drug-eluting stent (DES).

METHOD

This retrospective observational study included 134 patients undergoing PCI with 2.0-mm zotarolimus DES from December 2016 to May 2020. The primary endpoint was major adverse cardiovascular events (MACE) at 2-year follow-up, which was composed of all-cause mortality, target vessel myocardial infarction, and ischemia-driven target lesion revascularization. Multiple logistic regression analysis was used to identify the independent predictors of MACE, and odds ratios (OR) and 95% confidence intervals (CI) were calculated.

RESULT

The lesions were diffuse (mean length 20.9 ± 5.51 mm) and belong to type B2/C lesions (90.3%). On follow-up, the MACE rate was 20.1% and mostly driven by late lumen loss demanding revascularization (11.9%). In multivariable analysis, chronic kidney disease (CKD) (OR: 4.291, 95% CI: 1.574-11.704, p = 0.004) and calcified lesions (OR: 3.688, 95% CI: 1.311-10.371, p = 0.013) were the independent predictors of subsequent cardiovascular events, whereas statin was associated with better outcomes (OR: 0.335, 95% CI: 0.119-0.949, p = 0.040).

CONCLUSION

2.0-mm DES is a feasible option for treating very small vessel CAD in complex lesions. Patients with CKD and calcified lesions carry the hazard of worse outcomes, and careful consideration should be taken before stenting in this high-risk population.

Autoantibodies to Oxidatively Modified Peptide: Potential Clinical Application in Coronary Artery Disease

Coronary artery disease (CAD) is a global health issue. Lipid peroxidation produces various by-products that associate with CAD, such as 4-hydroxynonenal (HNE) and malondialdehyde (MDA). The autoantibodies against HNE and MDA-modified peptides may be useful in the diagnosis of CAD. This study included 41 healthy controls (HCs) and 159 CAD patients with stenosis rates of <30%, 30−70%, and >70%. The plasma level of autoantibodies against four different unmodified and HNE-modified peptides were measured in this study, including CFAH1211−1230, HPT78−108, IGKC2−19, and THRB328−345. Furthermore, feature ranking, feature selection, and machine learning models have been utilized to exploit the diagnostic performance. Also, we combined autoantibodies against MDA and HNE-modified peptides to improve the models’ performance. The eXtreme Gradient Boosting (XGBoost) model received a sensitivity of 78.6% and a specificity of 90.4%. Our study demonstrated the combination of autoantibodies against oxidative modification may improve the model performance.

Pediatric Mineral and Bone Disorder of Chronic Kidney Disease and Cardiovascular Disease

Chronic kidney disease is common and causes significant morbidity including shortened lifespans and decrease in quality of life for patients. The major cause of mortality in chronic kidney disease is cardiovascular disease. Cardiovascular disease within the chronic kidney disease population is closely tied with disordered calcium and phosphorus metabolism and driven in part by renal bone disease. The complex nature of renal, bone, and cardiovascular diseases was renamed as mineral and bone disorder of chronic kidney disease to encompass how bone disease drives vascular calcification and contributes to the development of long-term cardiovascular disease, and recent data suggest that managing bone disease well can augment and improve cardiovascular disease status. Pediatric nephrologists have additional obstacles in optimal mineral and bone disorder of chronic kidney disease management such as linear growth and skeletal maturation. In this article, we will discuss cardiovascular and bone diseases in chronic kidney disease and end-stage kidney disease patients with a focus on pediatric issues and concerns.

Inflammation and Oxidative Stress in Chronic Kidney Disease and Dialysis Patients

Significance: Chronic kidney disease (CKD) can be regarded as a burden of lifestyle disease that shares common underpinning features and risk factors with the aging process; it is a complex constituted by several adverse components, including chronic inflammation, oxidative stress, early vascular aging, and cellular senescence. Recent Advances: A systemic approach to tackle CKD, based on mitigating the associated inflammatory, cell stress, and damage processes, has the potential to attenuate the effects of CKD, but it also preempts the development and progression of associated morbidities. In effect, this will enhance health span and compress the period of morbidity. Pharmacological, nutritional, and potentially lifestyle-based interventions are promising therapeutic avenues to achieve such a goal. Critical Issues: In the present review, currents concepts of inflammation and oxidative damage as key patho-mechanisms in CKD are addressed. In particular, potential beneficial but also adverse effects of different systemic interventions in patients with CKD are discussed. Future Directions: Senotherapeutics, the nuclear factor erythroid 2-related factor 2-kelch-like ECH-associated protein 1 (NRF2-KEAP1) signaling pathway, the endocrine klotho axis, inhibitors of the sodium-glucose cotransporter 2 (SGLT2), and live bio-therapeutics have the potential to reduce the burden of CKD and improve quality of life, as well as morbidity and mortality, in this fragile high-risk patient group. Antioxid. Redox Signal. 35, 1426-1448.

Outcomes after ticagrelor versus clopidogrel treatment in end-stage renal disease patients with acute myocardial infarction: a nationwide cohort study

Clinical outcomes are unknown after ticagrelor treatment in patients with end-stage renal disease (ESRD) who are diagnosed with acute myocardial infarction (AMI). ESRD patients who were on hemodialysis and received dual antiplatelet therapy (DAPT) for AMI between July 2013 and December 2016 were identified in Taiwan's National Health Insurance Research Database. Using stabilized inverse probability of treatment weighting, patients receiving aspirin plus ticagrelor (n = 530) were compared with those receiving aspirin plus clopidogrel (n = 2462) for the primary efficacy endpoint, a composite of all-cause death, nonfatal myocardial infarction, or nonfatal stroke, and bleeding, defined according to the Bleeding Academic Research Consortium. Study outcomes were compared between the two groups using Cox proportional hazards model or competing risk model for the hazard ratio or subdistribution hazard ratio (SHR). During 9 months of follow-up, ticagrelor was comparable to clopidogrel with respect to the risks of primary efficacy endpoint [11.69 vs. 9.28/100 patient-months; SHR, 1.16; 95% confidence interval (CI) 0.97–1.4] and bleeding (5.55 vs. 4.36/100 patient-months; SHR 1.14; 95% CI 0.88–1.47). In conclusion, among hemodialysis patients receiving DAPT for AMI, ticagrelor was comparable to clopidogrel with regard to the composite efficacy endpoint and bleeding.

Association between phosphate and long-term outcome in CAD patients underwent coronary intervention

Phosphate has been linked to higher cardiovascular (CV) risk. However, whether phosphate is associated with poor outcomes for patients with coronary artery disease (CAD) after percutaneous coronary interventions (PCIs) remained undetermined. 2,894 CAD patients (2,220 male, aged 71.6 ± 12.2), who received PCI at TVGH from 2006 to 2015, with phosphate measurement, were enrolled. The primary outcome was the composite of major adverse CV events [MACE, comprising of CV death, nonfatal MI, and nonfatal stroke] and heart failure hospitalization (HHF). The key secondary outcome was MACE. There was a J-curve association between phosphate and CV events after adjusted for comorbidities and renal function. Phosphate around 3.2 ± 0.1 mg/dL was associated with the lowest CV risk. In Cox analysis, each 1 mg/dL increases in phosphate was associated with a higher risk of MACE + HHF (HR: 1.12, 95% CI: 1.05–1.21): CV death (HR: 1.37, 95% CI: 1.22–1.55) and HHF (HR: 1.12, 95% CI: 1.02–1.23). Subgroup analyses showed more prominent association between phosphate and MACE + HHF in male, age > 65, bare-metal stents (BMSs), LVEF < 50%, eGFR < 60, LDL > 70 mg/dL, and emergent PCI. Phosphate has a significant association with the risk of CV events in CAD patients undergoing PCI that was independent of comorbidities and renal function.

The relationship between calcification inhibitor levels in chronic kidney disease and the development of atherosclerosis

Aim

We aimed to investigate the factors affecting the development of atherosclerosis and the role of calcification inhibitors fetuin-A, matrix-Gla protein (MGP), osteoprotegerin (OPG) in atherosclerosis progress.

Material and methods

The study was planned to investigate the relationship of serum OPG, MGP and fetuin-A levels with the development of atherosclerosis in the stage 2–3–4–5 chronic kidney disease (CKD) patients who did not require dialysis treatment.

Results

32 (17 female, 15 male) healthy individuals and 92 (49 females, 43 males) CKD patients were included. The mean carotid intima-media thickness (CIMT), C-reactive protein (CRP), fetuin-A, OPG and MGP of the two groups were compared statistically. In CKD patients, age, body mass index (BMI), CRP, triglyceride, urea, systolic blood pressure (SBP), fasting blood sugar have a positive linear relationship, fetuin-A, OPG, GFR have a negative linear relationship with CIMT. The mean CIMT, right CIMT, left CIMT, blood urea, CRP, urinary albumin excretion creatinine and age show a negative linear relationship with fetuin-A.

Conclusion

Fetuin-A levels begin to decline from the early stages of CKD and are significantly lower in patients with atherosclerosis as expressed with CIMT. This suggests that fetuin-A may be used as an early marker in CKD for increased cardiovascular risk. Early recognition of these risk factors is important and large-scale studies on vascular calcification inhibitors are needed.

Evaluation of the causes affecting the development of pruritus in patients with peritoneal dialysis

BACKGROUND

Several factors play a role in the pathogenesis of pruritus in uremic patients. The pathophysiology is complex and many factors have been identified in these patients. The aim of this study was to investigate the presence, severity, and possible causes of pruritus in patients with peritoneal dialysis (PD) .

METHODS

Eighty patients, who received continuous ambulatory peritoneal dialysis (CAPD) treatment, were included in this study. Biochemical measurements, parathormone, C-reactive protein (CRP), and vitamin B12 levels of all the patients were recorded. Furthermore, substance P (SP) levels were measured by ELISA methods. Patients were examined by a dermatologist and pruritus degrees were queried using the visual analog score (VAS) with skin dryness.

RESULTS

In generalized linear model analysis, total urea clearance and SP independently predicted VAS scores. SP was significantly predictive in ROC analysis in identifying the VAS score in patients with peritoneal dialysis. The sensitivity and specificity of SP were 80% and 67% (cut-off > 364), respectively, with an area under the ROC curve of 0.757 (95% CI 0.650-0.865, p < 0.001). SP also was significantly predictive in ROC analysis in identifying xerosis in PD patients.

CONCLUSION

Pruritus was proportional to the amount of substance P and total urea clearance was another reason affecting pruritus in peritoneal dialysis patients.

Clinical Outcomes of Dialysis Patients Treated with Drug-Eluting Stent for Left Main Distal Bifurcation Lesions

AIMS

We assessed clinical outcomes after percutaneous coronary intervention (PCI) for unprotected left main coronary artery (ULMCA) distal bifurcation lesions using drug-eluting stents (DES) in hemodialysis (HD) patients compared to non-HD patients.

METHODS AND RESULTS

We identified 1,858 consecutive patients who underwent PCI for ULMCA distal bifurcation lesions at 4 high-volume centers in Japan, Italy, and Taiwan between January 2005 and December 2015. Of them, 1,416 patients were treated with DES including 113 HD patients and 1,303 non-HD patients. The primary end point was target lesion failure (TLF) defined as a composite of cardiac death, target lesion revascularization (TLR), and myocardial infarction. HD patients were more likely to be younger and have diabetes mellitus, dyslipidemia, peripheral artery disease, lower ejection fraction, and higher EuroSCORE. TLF rate at 3 years was significantly higher in HD group than in non-HD group (adjusted hazard ratio [HR] 2.43 [1.75-3.38], p < 0.001). Cardiac mortality and TLR rate were also significantly higher in HD group than in non-HD group (adjusted HR 3.85 [2.34-6.34], p < 0.001, and HR 2.10 [1.41-3.14], p < 0.001, respectively).

CONCLUSIONS

HD was strongly associated with adverse cardiac events after PCI for ULMCA distal bifurcation lesions with DES.

Management of acute intradialytic cardiovascular complications: Updated overview (Review)

An increasing number of patients require renal replacement therapy through dialysis and renal transplantation. Chronic kidney disease (CKD) affects a large percentage of the world's population and has evolved into a major public health concern. Diabetes mellitus, high blood pressure and a family history of kidney failure are all major risk factors for CKD. Patients in advanced stages of CKD have varying degrees of cardiovascular damage. Comorbidities of these patients, include, on the one hand, hypertension, hyperlipidemia, hyperglycemia, hyperuricemia and, on the other hand, the presence of mineral-bone disorders associated with CKD and chronic inflammation, which contribute to cardiovascular involvement. Acute complications occur quite frequently during dialysis. Among these, the most important are cardiovascular complications, which influence the morbidity and mortality rates of this group of patients. Chronic hemodialysis patients manifest acute cardiovascular complications such as intradialytic hypotension, intradialytic hypertension, arrhythmias, acute coronary syndromes and sudden death. Thus, proper management is extremely important.

Chronic Kidney Disease-Associated Inflammation Increases the Risks of Acute Kidney Injury and Mortality after Cardiac Surgery

Cardiovascular mortality increases with decreasing renal function although the cause is yet unknown. Here, we have investigated whether low chronic inflammation in chronic kidney diseases (CKD) could contribute to increased risk for coronary artery diseases (CAD). Thus, a prospective case–control study was conducted in patients with CAD and CKD undergoing coronary artery bypass graft surgery with the aim of detecting differences in cardiovascular outcomes, epicardial adipose tissue volume, and inflammatory marker activity associated with renal dysfunction. Expression of membrane CD14 and CD16, inflammatory cytokines and chemokines, mitogen-activated protein (MAP) kinases and hsa-miR-30a-5p were analyzed in peripheral blood mononuclear cells (PBMCs). Epicardial fat volume and tissue inflammation in perivascular adipose tissue and in the aorta were also studied. In the present study, 151 patients were included, 110 with CAD (51 with CKD) and 41 nonCAD controls (15 with CKD). CKD increased the risk of cardiac surgery–associated acute kidney injury (CSA-AKI) as well as the 30-day mortality after cardiac surgery. Higher counts of CD14⁺⁺CD16⁺ monocytes were associated with vascular inflammation, with an increased expression of IL1β, and with CKD in CAD patients. Expression of hsa-miR-30a-5p was correlated with hypertension. We conclude that CKD patients show an increased risk of CSA-AKI and mortality after cardiovascular surgery, associated with the expansion of the CD14⁺⁺CD16⁺ subset of proinflammatory monocytes and with IL1β expression. We propose that inflammation associated with CKD may contribute to atherosclerosis (ATH) pathogenesis.

Use of proteomics to identify biomarkers associated with chronic kidney disease and long-term outcomes in patients with myocardial infarction

BACKGROUND

Patients with chronic kidney disease (CKD) have poor outcomes following myocardial infarction (MI). We performed an untargeted examination of 175 biomarkers to identify those with the strongest association with CKD and to examine the association of those biomarkers with long-term outcomes.

METHODS

A total of 175 different biomarkers from MI patients enrolled in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry were analysed either by a multiple reaction monitoring mass spectrometry assay or by a multiplex assay (proximity extension assay). Random forests statistical models were used to assess the predictor importance of biomarkers, CKD and outcomes.

RESULTS

A total of 1098 MI patients with a median estimated glomerular filtration rate of 85 mL min^-1 /1.73 m² were followed for a median of 3.2 years. The random forests analyses, without and with adjustment for differences in demography, comorbidities and severity of disease, identified six biomarkers (adrenomedullin, TNF receptor-1, adipocyte fatty acid-binding protein-4, TNF-related apoptosis-inducing ligand receptor 2, growth differentiation factor-15 and TNF receptor-2) to be strongly associated with CKD. All six biomarkers were also amongst the 15 strongest predictors for death, and four of them were amongst the strongest predictors of subsequent MI and heart failure hospitalization.

CONCLUSION

In patients with MI, a proteomic approach could identify six biomarkers that best predicted CKD. These biomarkers were also amongst the most important predictors of long-term outcomes. Thus, these biomarkers indicate underlying mechanisms that may contribute to the poor prognosis seen in patients with MI and CKD.

Characteris Tics and Causes of Immune Dysfunction Related to Uremia and Dialysis

From the immunologic viewpoint, chronic kidney disease (CKD) is characterized by disorders of both the innate and adaptive systems, generating a complex and still not fully understood immune dysfunction. Markers of a chronically activated immune system are closely linked to several complications of CKD and represent powerful predictors for mortality in the CKD population. On the other hand, CKD patients respond poorly to vaccination and to challenges such as bacterial infection. Interestingly, the main causes of death in patients with CKD are cardiovascular and infectious diseases, both being pathologic processes closely linked to immune function. Therefore, accelerated tissue degeneration (as a consequence of chronic inflammation) and increased rate of sepsis (because of a poorly orchestrated immune response) represent the most important targets for interventions aiming to reduce mortality in CKD patients. Understanding the mechanisms behind the immune dysfunction that is peculiar to CKD generates a perspective to improve outcomes in this group of patients.

Impact of hemodialysis on clinical and angiographic outcomes in in-stent restenotic lesions following optical coherence tomography-guided drug-coated balloon treatment

Hemodialysis (HD) is associated with a high in-stent restenosis (ISR) rate even in the second-generation era. Drug-coated balloons (DCB) generally provide excellent clinical outcomes in patients with ISR lesions. Nonetheless, safety and efficacy of DCB for ISR lesions in HD patients are largely unknown. A total of 17 centers across Japan participated in this study. Patients were eligible for the study if ISR lesions were treated with DCB. Enrolled patients were divided into 2 groups (HD and non-HD groups). Angiographic, OCT, and clinical outcomes were compared between the HD and the non-HD groups. A total of 210 patients were enrolled (36 patients in the HD group, and 174 patients in the non-HD group). At 8 months, the binary restenosis rate was significantly higher (26.3% versus 11.3%, p = 0.02) and in-segment late loss was significantly higher (0.49 ± 0.61 mm versus 0.23 ± 0.33 mm, p = 0.02) in the HD group than the non-HD group. In the OCT analyses, change of minimum stent area between post- and pre-procedure was significantly smaller in the HD group compared to the non-HD group (0.08 ± 0.95 mm² versus 0.68 ± 1.07 mm², p = 0.004). Target vessel failure (TVF) rate at 2 years was significantly different between the 2 groups (25.0% in the HD group and 12.1% in the non-HD group, p = 0.04). In the multivariate analysis, HD was a significant predictor for TVF (Hazard ratio 5.81, 95% CI 1.28-26.4, p = 0.02). Clinical and angiographic outcomes following OCT-guided DCB treatment in ISR lesions were significantly worse in HD patients compared to non-HD patients.Clinical Trial Registration Information: https://clinicaltrials.gov/ct2/show/NCT02300454.

Fasting plasma glucose, lipid ratios, and atherogenic coefficient are the risk factors for hypertension in chronic kidney disease patients on hemodialysis: A report from the Regional High Speciality Hospital of Peninsular Yucatan, Mexico

Chronic kidney disease (CKD) is associated with the development of cardivascular disease (CVD). CKD is one of the major public health problems in Mexico. Derived parameters of lipid profile, namely atherogenic index of plasma (AIP), atherogenic coefficient (AC), and Castelli risk index (CRI I and CRI II) are useful for predicting hypertension among CKD patients on hemodialysis that are not widely reported from Mexico. Objective of the present study was to find interrelationships among blood pressure, fasting plasma glucose (FPG), and derived parameters of lipid profile (AIP, AC, CRI-I, and CRI-II) among adult CKD patients on hemodialysis in a hospital in Yucatan, Mexico. Methods: An observational study was performed using the medical records (2016 and 2017) of 47 CKD patients on hemodialysis in the Regional High Speciality Hospital of Yucatan Peninsula (HRAEPY in Spanish acronym). Multiple linear regression models were developed to evaluate the use of FPG level and derived parameters of lipid profile (AC, CRI-I, and CRI-II) as risk factors predicting mean arterial pressure (MAP). Results showed remarkable prevalence of excess weight (55% overweight, 15% obesity) and hypertension (64%) in the sample. Correlation coeffcients and multiple linear regression models showed significant rise of blood pressure in association with elevated FPG level and derived lipid profile parameters. The results confirm the use of FPG, AC, CRI-I and CRI-II as the indicators for an early diagnosis of hypertension and related CVDs among CKD patients on hemodialysis.

COVID's Razor: RAS Imbalance, the Common Denominator Across Disparate, Unexpected Aspects of COVID-19

A modern iteration of Occam's Razor posits that "the simplest explanation is usually correct." Coronavirus Disease 2019 involves widespread organ damage and uneven mortality demographics, deemed unexpected from what was originally thought to be "a straightforward respiratory virus." The simplest explanation is that both the expected and unexpected aspects of COVID-19 share a common mechanism. Silent hypoxia, atypical acute respiratory distress syndrome (ARDS), stroke, olfactory loss, myocarditis, and increased mortality rates in the elderly, in men, in African-Americans, and in patients with obesity, diabetes, and cancer-all bear the fingerprints of the renin-angiotensin system (RAS) imbalance, suggesting that RAS is the common culprit. This article examines what RAS is and how it works, then from that baseline, the article presents the evidence suggesting RAS involvement in the disparate manifestations of COVID-19. Understanding the deeper workings of RAS helps one make sense of severe COVID-19. In addition, recognizing the role of RAS imbalance suggests potential routes to mitigate COVID-19 severity.

The Impact of Diabetes Mellitus on Clinical Outcomes after Percutaneous Coronary Intervention with Drug-Eluting Stents for Left Main Distal Bifurcation Lesions in Patients with Chronic Kidney Disease

BACKGROUND

The impact of diabetes mellitus (DM) on clinical outcomes after percutaneous coronary intervention (PCI) for unprotected left main (ULM) distal bifurcation lesions in patients with chronic kidney disease (CKD) is poorly understood in the era of drug-eluting stents (DESs).

OBJECTIVE

We assessed the impact of DM on clinical outcomes after PCI for ULM distal bifurcation lesions in CKD patients compared to patients without DM.

METHODS

We identified 1,832 consecutive patients who underwent PCI for ULM lesions at New Tokyo Hospital, Matsudo, Japan, San Raffaele Scientific Institute, Milan, Italy, and EMO-GVM, Centro Cuore Columbus, Milan, Italy between January 2005 and August 2015. Of the 1,832 patients, 1,391 were treated with DESs. We excluded 750 patients without CKD and 89 hemodialysis patients. Finally, 552 patients with CKD were included: 219 with DM (DM group) and 333 without DM (no DM group). The primary endpoint was target lesion failure (TLF) at 5 years. TLF was defined as a composite of cardiac death, target lesion revascularization (TLR), and myocardial infarction.

RESULTS

Patients in the DM group were more likely to have hypertension, dyslipidemia, peripheral artery disease, and lower ejection fraction and were more frequently using insulin for DM. The TLF rate during the follow-up period was significantly higher in the DM than in the no DM group (adjusted hazard ratio [HR] 1.50; 95% confidence interval [CI] 1.06-2.13; p = 0.023). Cardiac mortality was comparable between both groups (adjusted HR 1.11; 95% CI 0.63-1.95; p = 0.71). The TLR rate was significantly higher in the DM group than in the no DM group (adjusted HR 1.69; 95% CI 1.12-2.54; p = 0.012).

CONCLUSION

DM is strongly associated with adverse event after PCI for ULM distal bifurcation lesions in CKD patients compared to those without DM.

The effects of mutation and modification on the structure and stability of human lysozyme: A molecular link between carbamylation and atherosclerosis

Amino acid mutations in some proteins such as lysozyme lead to genetically disorder variants and adverse pathogenic consequences. Recently, amino acid modifications were known as a risk factor in many related diseases such as uremia and atherosclerosis, showing the importance of these surface-structure changes. Although the structural consequences of the hereditary proteins have been examined extensively, such effects for the protein modifications are known to a lesser extent. One drawback in the examination of protein modifications is hardness in experimental detection of modifications by techniques such as NMR and crystallography. Molecular modeling and simulation can help to understand such phenomena at the molecular levels. It is more rational that the effects of both mutation and modification can be compared in a single protein model. Here, molecular dynamics simulation is used to compare the effects of a disease-related carbamylation modification and an amyloidogenic mutation (D67H) in human lysozyme as a model protein. The results show that the carbamylation adversely effects on the tertiary structure, leading to the similar unfolding pathway to the hereditary amyloidogenic form. The carbamylation leads to the instability of the overall protein conformation, especially on the β-domain, which is a characteristic of hereditary amyloidosis in human lysozymes. The aggregation behaviors of both modified and mutant lysozyme were examined by molecular docking calculations. The results showed that the partially unfolded lysozyme might form tight protein aggregates upon carbamylation similar to the amyloidogenic variant. Both single and all-residues carbamylations impose serious conformational changes to the tertiary structure of lysozyme. It was obtained that carbamylation of lysozyme strongly effects on the stability of N-terminal β-sheet, which can produce a highly unstable conformation. The results of this study not only show the adverse structural consequences of a disease-associated post-translational modification, but it also may be very helpful to understand the molecular basis for many carbamylation-related diseases such as atherosclerosis in ESRD patients. The results show that non-native post-translational modifications may be as structurally important as hereditary mutations.

Chronic Inflammation in Peritoneal Dialysis: The Search for the Holy Grail?

Mortality and morbidity in chronic kidney disease (CKD) patients are unacceptably high. The annual mortality rate due to cardiovascular disease (CVD) is approximately 9%, which, for the middle-aged person, is at least 10- to 20-fold higher than for the general population. Classic risk factors for CVD are highly prevalent in CKD patients, but they cannot fully account for the excessive rate of CVD in this population. Instead, it has become increasingly clear that nontraditional risk factors, such as systemic inflammation, may play a key role in the development of atherosclerosis. It is well established that inflammatory markers are very powerful predictors of high CVD morbidity and mortality not only in the general population, but particularly in CKD patients. Signs of a sustained low-grade inflammation, such as increased levels of C-reactive protein (CRP), are present in the majority of stage 5 CKD patients, even in patients in clinically stable condition, and they are also commonly observed after the initiation of dialysis therapy. Dialysis therapy — hemodialysis as well as peritoneal dialysis (PD) — may itself contribute to systemic inflammation. Local intraperitoneal inflammation can also occur in patients treated with PD. These local effects may result in a low-grade inflammation, caused by the bioincompatibility of conventional glucose-based dialysis fluids, to intense inflammation associated with peritonitis. Given these circumstances, it is reasonable to hypothesize that strategies aiming to reduce inflammation are potentially important and novel, and could serve to reduce CVD, thereby lowering morbidity and mortality in patients with CKD. In this review we provide information supporting the hypothesis that systemic inflammation is tightly linked to the most common complications of CKD patients, in particular those on PD, and that local inflammation in PD may contribute to various related complications. The aims of this review are to discuss the reasons that make inflammation an attractive target for intervention in CKD, the particular aspects of the inflammation–CVD axis during PD treatment that are likely involved, and possible means for the detection and management of chronic inflammation in PD patients.

Peritoneal dialysis-related peritonitis as a risk factor for cardiovascular events

BACKGROUND

Cardiovascular disease is the leading cause of mortality in peritoneal dialysis (PD) patients. Infection is known to increase the risk of cardiovascular events (CVE); however, no studies have examined the association between PD peritonitis and CVE.

AIM

To examine peritonitis as a risk factor for CVE in PD patients.

METHODS

This retrospective cohort study included all adults undertaking PD for ≥3 months in one Australian health district from 2001 to 2015. Baseline characteristics and peritonitis event information was obtained from the Australian and New Zealand Dialysis and Transplant registry. The Centre for Health Research Illawarra Shoalhaven Population facilitated data linkage using ICD10 coding to capture CVE information.

RESULTS

A total of 211 patients was included, with median age of 66 years (interquartile range 54.49-74.45); 64% were male. Peritonitis occurred in 114 (54%) patients and 65 (30.8%) patients experienced a CVE. Identified risk factors for CVE included: cerebrovascular disease (hazard ratio (HR) 2.72, 95% confidence interval (CI) 1.36-5.47), diabetes (HR 2.41, 95% CI 1.47-3.96), coronary artery disease (HR 1.67, 95% CI 1.01-2.77) and age (HR 1.03, 95% CI 1.01-1.06). There was no significant increase in risk of CVE following peritonitis (HR 1.37, 95% CI 0.81-2.32, P = 0.24), even when accounting for age, cerebrovascular disease, diabetes and existing coronary artery disease (HR 1.32, 95% CI 0.78-2.23, P = 0.30).

CONCLUSIONS

We did not find an increase in the risk of CVE following a peritonitis episode in PD patients. This result may be due to small sample size or rapid peritonitis treatment mitigating cardiovascular risk.

Copeptin is independently associated with vascular calcification in chronic kidney disease stage 5

BACKGROUND

Vascular calcification (VC) is an independent predictor of cardiovascular disease (CVD) present in 30-70% of patients with chronic kidney disease (CKD). Copeptin is a sensitive surrogate marker of arginine vasopressin (AVP), which is involved in many pathophysiologic processes in CKD. The aim of the present study was to explore the association of copeptin with VC in CKD stage 5.

METHODS

Copeptin was investigated in conjunction with living donor kidney transplantation in 149 clinically stable CKD stage 5 patients (CKD5), including 53 non-dialyzed (CKD5-ND) and 96 dialysis patients treated by peritoneal dialysis (PD) (n = 43) or hemodialysis (HD) (n = 53). We analyzed the association of copeptin with presence and extent of VC ascertained both histologically in biopsies from the inferior epigastric artery (n = 137) and by coronary artery calcification (CAC) score measured by computed tomography.

RESULTS

Patients with higher copeptin were older, had higher systolic blood pressure, higher prevalence of CVD and their preceding time on chronic dialysis was longer. In Spearman's rank correlations (Rho), copeptin concentrations were significantly associated with CAC score (Rho = 0.27; p = 0.003) and presence of medial VC (Rho = 0.21; p = 0.016). Multivariate logistic regression analysis showed that 1-SD higher age, male gender, diabetes and 1-SD higher copeptin were significantly associated with the presence of moderate-extensive VC.

CONCLUSIONS

High circulating levels of copeptin in CKD5 patients are independently associated with the degree of medial calcification ascertained by histology of arterial biopsies. Thus, plasma copeptin may serve as a marker of the uremic calcification process.

Kidney transplantation and cardiomyopathy: Concepts and controversies in clinical decision-making

Increasing comorbidities and an aging population have led to a tremendous increase in the burden of both kidney and cardiac dysfunction. Concomitant cardiomyopathy exposes the patients with kidney disease to further physiological, hemodynamic, and pathologic alterations. Kidney transplantation imposes lesser anesthetic and surgical complexities compared to another solid organ transplant. The surgical decision-making remains an unsettled issue in these conditions. The surgical choices, techniques, and sequences in kidney transplant and cardiac surgery depend on the pathophysiological perturbations and perioperative outcomes. The absence of randomized controlled trials eludes us from suggesting definite management protocol in patients with end-stage kidney disease with cardiomyopathy. Nevertheless, in this review, we extracted data from published literature to understand the pathophysiologic interactions between end-stage renal diseases with cardiomyopathy and also proposed the management algorithm in this challenging scenario. The proposed management algorithm would ensure consensus across all stakeholders involved in decision-making. Our simplistic evidence-based approach would augur future randomized trials and would further ensure refinement in our management approach after the emergence of more definitive evidence.

Pathophysiological Implication of Fetuin-A Glycoprotein in the Development of Metabolic Disorders: A Concise Review

Alpha 2-Heremans-Schmid glycoprotein, also known as fetuin-A (Fet-A), is a multifunctional plasma glycoprotein that has been identified in both animal and human beings. The protein is a hepatokine predominantly synthesized in the liver, which is considered as an important component of diverse normal and pathological processes, including bone metabolism regulation, vascular calcification, insulin resistance, and protease activity control. Epidemiological studies have already consistently demonstrated significant elevated circulating Fet-A in the course of obesity and related complications, such as type 2 diabetes mellitus, metabolic syndrome, and nonalcoholic fatty liver disorder (NAFLD). Moreover, Fet-A has been strongly correlated with many parameters related to metabolic homeostasis dysregulation, such as insulin sensitivity, glucose tolerance, circulating lipid levels (non-esterified free fatty acids and triglycerides), and circulating levels of both pro- and anti-inflammatory factors (C-reactive protein, tumor necrosis factor-α (TNF-α), and interleukin (IL)-6). Metabolic-interfering effects of Fet-A have thus been shown to highly exacerbate insulin resistance (IR) through blocking insulin-stimulated glucose transporter 4 (GLUT-4) translocation and protein kinase B (Akt) activation. Furthermore, the protein appeared to interfere with downstream phosphorylation events in insulin receptor and insulin receptor substrate signaling. The emerging importance of Fet-A for both diagnosis and therapeutics has therefore come to the attention of researchers and the pharmaceutical industry, in the prospect of developing new therapeutic strategies and diagnosis methods for metabolic disorders.

SWEDEHEART-1-year data show no benefit of newer generation drug-eluting stents over bare-metal stents in patients with severe kidney dysfunction following percutaneous coronary intervention

BACKGROUND

We hypothesized that the transition from bare-metal stents (BMS) to newer generation drug-eluting stents (n-DES) in clinical practice may have reduced the risk also in patients with kidney dysfunction.

METHODS

Observational study in the national SWEDEHEART registry, that compared the 1-year risk of in-stent restenosis (RS) and stent thrombosis (ST) in all percutaneous coronary intervention treated patients(n = 92 994) during 2007-2013.

RESULTS

N-DES patients were younger than BMS, but had more often diabetes, previous myocardial infarction, previous revascularization and were more often treated with potent platelet inhibition. N-DES versus BMS, was associated with lower 1-year risk of RS in patients with estimated glomerular filtration rate (eGFR) >60 with a cumulative probability of 2.1% versus 5.3%, adjusted hazard ratio 0.30, 95% CI (0.27-0.34) and with eGFR 30-60: 3.0% versus 4.9%; hazard ratio 0.46 (0.36-0.60) but not in patients with eGFR <30: 8.1% versus 6.0%; hazard ratio 1.32 (0.71-2.45) (pinteraction = 0.009) as well as lower risk of ST for eGFR >60 and eGFR 30-60: 0.5% versus 0.9%; hazard ratio 0.52 (0.40-0.68) and 0.6% versus 1.3%; hazard ratio 0.54 (0.54-0.72) but not for eGFR <30; 2.1% versus 1.1%; hazard ratio 1.49 (0.56-3.98) (pinteraction = 0.027).

CONCLUSION

N-DES is associated with lower 1-year risk of in-stent restenosis and stent thrombosis in patients with normal or moderately reduced kidney function but not in patients with severe kidney dysfunction, where stenting is associated with worse outcomes regardless of stent type.

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.

Clinical implications of fetuin-A

Fetuin-A, also termed alpha2-Heremans-Schmid glycoprotein, is a 46kDa hepatocyte derived protein (hepatokine) and serves multifaceted functions.

Cardiovascular Disease After Kidney Transplant

Renal transplantation is the preferred treatment for patients with end-stage kidney disease. However, despite successful kidney transplantation, cardiovascular disease (CVD) remains one of the major causes of patient death and hence graft loss. The antecedents of this increased risk reside within the development of end-stage kidney disease and dialysis. Risk factors for the development of CVD include diabetes, hypertension, and dyslipidemia. Other transplant-specific factors include the presence of a patent arteriovenous fistula and immunosuppressive therapy. Efforts to modify these factors should be strongly encouraged to improve long-term outcomes of transplant patients and reduce death from CVD in this at-risk patient population.

Peritonitis as a risk factor for long-term cardiovascular mortality in peritoneal dialysis patients: The case of a friendly fire?

AIM

Since the impact of peritonitis on long-term non-infectious mortality has not been investigated until the present, the aim of this study was to analyze the impact of peritonitis on long-term cardiovascular (CV) mortality in a large peritoneal dialysis (PD) cohort.

METHODS

The analysis was based on BRAZPD II, a national prospective cohort study that recruited patients in Brazilian centres from December 2004 to January 2011. Incident adult PD patients with at least 90 days on treatment were included in the analysis. Cardiovascular death occurring after a minimum of 30 days after a peritonitis episode was considered the primary endpoint. Cox regression analysis for time-dependent variables was used for the adjustments.

RESULTS

There were 2405 episodes of peritonitis in 5707 patients (48% males, 44% diabetes, 73% hypertensive). Patients with one episode of peritonitis presented a 22% increase in the hazard ratio of late CV mortality compared to those who never experienced peritonitis (HR1.22; CI95%1.01-1.47). Adjusted hazard for CV mortality showed a stepwise negative effect on survival for each additional peritonitis episode of infection: two episodes (HR1.78; CI95%1.31-2.42), three episodes (HR2.81; CI95%1.83-4.32) and four episodes (HR3.84; CI95%2.01-7.32).

CONCLUSION

Peritonitis was an independent predictor of CV mortality and the frequency of peritonitis was strongly associated with an increase in this risk. This is the first study to demonstrate the impact of peritonitis on late cardiovascular mortality of PD patients, suggesting a link between acute inflammation and cardiovascular outcomes.

Five-year clinical outcomes of everolimus-eluting stents from the post marketing study of CoCr-EES (XIENCE V/PROMUS) in Japan

The Cobalt Chromium Everolimus-Eluting Stent (CoCr-EES) Post Marketing Surveillance (PMS) Japan study is a prospective multicenter registry designed to evaluate the safety and efficacy of XIENCE V/PROMUS everolimus-eluting stents in routine clinical practice at 47 centers representative of the clinical environment in Japan. We enrolled 2010 consecutive patients (2649 lesions) who underwent percutaneous coronary intervention using CoCr-EES. Clinical outcomes were evaluated through 5 years. Mean age was 68.8 years, 41.9% had diabetes, 4.9% received hemodialysis. Five-year clinical follow up was available for 1704 (84.8%) patients. Major adverse cardiovascular events (MACE) occurred in 10.7% of patients, including cardiac death (3.8%), myocardial infarction (1.8%), and clinically driven target lesion revascularization (TLR) (6.0%). Beyond 1 year, annual incidence of clinically driven TLR was 0.5-0.8%. Definite or probable stent thrombosis occurred in 9 (0.5%) patients at 5 years. After 1 year, definite stent thrombosis occurred in only 1 patient. Significant predictors for MACE were dialysis (ODDs ratio 4.58, 95% CI 2.75-7.64), prior cardiac intervention (ODDs ratio 2.47, 95% CI 1.75-3.49), total stent length (ODDs ratio 1.01, 95% CI 1.01-1.02), and number of diseased vessels (ODDs ratio 1.66, 95% CI 1.08-2.55). Five-year clinical outcomes from the CoCr-EES PMS Japan study demonstrated a low incidence of clinical events in the daily practice up to 5 years.Clinical Trial Registration Information: https://clinicaltrials.gov/ct2/show/NCT01086228 .

Proportions of Proinflammatory Monocytes Are Important Predictors of Mortality Risk in Hemodialysis Patients

Despite the continuous progression in dialysis medicine, mortality and the burden of cardiovascular disease (CVD) among hemodialysis patients are still substantial. Substantial evidence suggests that proinflammatory (CD16+) monocytes contribute to the development of atherosclerosis. A cohort of 136 stable hemodialysis patients (follow-up: 6.25 year) was assessed to investigate the association between the proportion of CD16+ monocytes for all-cause and CVD mortalities. The CD16+ monocytes were associated with both mortalities after adjusting for a preexisting CVD history. Compared to the reference group (CD16+ monocytes within [15.6–18.6], the first and second quartile), patients with CD16+ monocytes above the highest quartile level (>21.5) had an adjusted hazard ratio (HR) of 30.85 (95% confidence interval [CI]: 7.12–133.8) for CVD mortality and 5.28 (2.07–13.49) for all-cause mortality, and those with CD16+ monocytes below the lowest quartile ≤15.6), had significantly elevated death risks after 3.5-year follow-up (HR [95% CI]: 10.9 [2.42–48.96] and 4.38 [1.45–13.24] for CV and all-cause mortalities, respectively). The hemodialysis patients with CD16+ monocyte level in a low but mostly covering normal range also portended a poor prognosis. The findings shed some light for nephrologists on future prospects of early recognizing immune dysfunction and improving early intervention outcomes.

Level of inflammatory factors in chronic hemodialysis patients with and without cardiovascular disease

Background:

Considering the existence of controversies about the predictive value of inflammatory markers for cardiovascular disease (CVD), we aimed to compare the level of high-sensitivity C-reactive protein (hs-CRP) and interlukin-6 (IL-6) level in chronic hemodialysis (HD) patients with and without CVD.

Materials and Methods:

In this historical cohort study, HD patients with and without CVD disease were enrolled. The presence of CVD risk factors, level of inflammatory factors including IL-6 and hs-CRP as well as lipid levels, fasting blood sugar, and other biochemical factors were compared in two studied groups.

Results:

During the study, eighty HD patients with (n = 40) and without (n = 40) CVD were enrolled. Diabetes was more prevalent among HD patients with CVD than those without CVD (P < 0.05). The level of IL-6 and hs-CRP were not different in two studied groups (P > 0.05). Univariate analysis of variance test indicated that there was not any significant relationship between hs-CRP and CVD (P > 0.05).

Conclusion:

The findings indicated that the level of inflammatory factors including hs-CRP and IL-6 are not significantly different in HD patients with and without CVD. However, for obtaining more definite conclusion in this field and evaluation their predicting role in this field, it is recommended to study other novel inflammatory markers as well as the additive effect of the inflammatory factors with traditional ones in larger sample size and longer follow-up.

Dual Antiplatelet Therapy and Clinical Outcomes after Coronary Drug-Eluting Stent Implantation in Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

We aimed to investigate the benefits and risks of dual antiplatelet therapy (DAPT) after coronary drug-eluting stent (DES) implantation in patients undergoing hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A nested case-control analysis of patients on hemodialysis after receipt of DES and DAPT treatment was conducted using data from Taiwan's National Health Insurance Research Database for the period 2007-2011. Cases of myocardial infarction or death within 1 year after DES implantation were matched one-to-one with control patients. Odds ratios were calculated to compare DAPT continuation with discontinuation. Additionally, a propensity score-adjusted 6-month landmark cohort analysis was also conducted to evaluate the long-term benefits and risks of prolonged (>6 months) compared with ≤6 months of DAPT use. The primary outcomes were death and myocardial infarction. The secondary outcomes were ischemic stroke, revascularization, and major bleeding.

RESULTS

In the nested case-control analysis, patients who continued DAPT had a lower rate of death or myocardial infarction within 1 year after receipt of a DES (adjusted odds ratio, 0.54; 95% confidence interval, 0.36 to 0.81; P=0.003), whereas this association became statistically nonsignificant when compared with patients who discontinued DAPT for the period between 6 and 12 months after receipt of a DES (adjusted odds ratio, 1.51; 95% confidence interval, 0.75 to 3.04). In the propensity score-adjusted cohort analysis, >6 months of DAPT use was not associated with different primary or secondary outcomes than shorter-term use.

CONCLUSIONS

Our findings support that the clinical effectiveness of extended DAPT in a hemodialysis population may be tempered after 6 months post-DES implantation.

Cardiovascular Disease in Patients with End-Stage Renal Disease on Hemodialysis

Cardiovascular disease is a major concern for patients with end-stage renal disease (ESRD), especially those on hemodialysis. ESRD patients with coronary artery disease often do not have symptoms or present with atypical symptoms. Coronary lesions in ESRD patients are characterized by increased media thickness, infiltration and activation of macrophages, and marked calcification. Several studies showed worsened clinical outcomes after coronary revascularization, which were dependent on the severity of renal dysfunction. ESRD patients on hemodialysis have the most severe renal dysfunction; thus, the clinical outcomes are worse in these patients than in those with other types of renal dysfunction. Medications for primary or secondary cardiovascular prevention are also insufficient in ESRD patients. Efficacy of drug-eluting stents is inferior in ESRD patients, compared to the excellent outcomes observed in patients with normal renal function. Unsatisfactory outcomes with trials targeting cardiovascular disease in patients with ESRD emphasize a large potential to improve outcomes. Thus, optimal strategies for diagnosis, prevention, and management of cardiovascular disease should be modified in ESRD patients.

Receptor for advanced glycation end products (RAGE) gene polymorphism and cardiovascular disease in end-stage renal disease patients

BACKGROUND/OBJECTIVES

Receptor for advanced glycation end products (RAGE) contributes to the pathogenesis of vascular and inflammatory diseases. We investigated whether the functional polymorphism in the promoter region of the RAGE gene (-374 T/A) influences development of cardiovascular disease in the end-stage renal disease (ESRD) patients.

METHODS

The cohorts of 1866 ESRD patients and 1143 healthy subjects were genotyped by polymerase chain reaction (PCR) for the RAGE variant rs1800624.

RESULTS

The genotype and allele frequencies did not differ significantly between ESRD patients and controls. There was no significant difference in the genotype distribution when patients with CVD were compared to those without it (p for A allele = 0.62). After stratifying CVD patients according to CVD clinical phenotype, the ESRD patients with stroke had a lower frequency of A allele than patients without CVD (0.12 vs. 0.21, p = 0.027). To confirm this finding, we genotyped 163 patients with ischemic stroke but without renal disease. In this group, the AA/TA genotypes were also significantly associated with lower risk of stroke (OR 0.46, p = 0.0002).

CONCLUSION

Our data suggest that the presence of the A allele of -374 T/A polymorphism in the RAGE gene has a protective effect against stroke.

Elevation of Interleukin-18 Correlates With Cardiovascular, Cerebrovascular, and Peripheral Vascular Events: A Cohort Study of Hemodialysis Patients

Cardiocerebral vascular events are the major cause of mortality among patients with end-stage renal disease (ESRD). Subclinical inflammation and atherosclerosis have been implicated in the pathophysiology of ESRD. Evidence has shown the crucial role of interleukin-18 (IL-18) in inflammation. Interleukin-18 has been markedly upregulated in ESRD patients. Nevertheless, the ability of the IL-18 level to predict cardiocerebral vascular events and the correlation between IL-18 levels and cardiocerebral vascular events have not been established in hemodialysis patients.To determine whether the serum IL-18 level predicts cardiocerebral vascular events, the authors studied 171 ESRD patients. Samples were collected and patients were followed for 24 months. Demographic data, the duration of hemodialysis, nutrition status, inflammatory parameters, dialysis adequacy, and lipid profiles were analyzed to predict the outcome by using multivariate logistic regression. Cutoff points were calculated by acquiring the highest Youden index. The Kaplan-Meier method was used to scrutinize the cumulative proportion of events.The multivariate logistic regression model revealed that serum creatinine, C-reactive protein, and IL-18 levels were independent predictors for cardiocerebral vascular events. The odds ratio of events for each increase in IL-18 (pg/mL) was 1.008 for cardiocerebral vascular events. The area under the receiver operating characteristic curve of IL-18 was 0.779 ± 0.039, the overall correctness was 73%, and the Youden index was highest at a cutoff of 463 pg/mL. In the Kaplan-Meier model, patients with an IL-18 level higher than 463 pg/mL exhibited the highest probability of experiencing an adverse event during the entire follow-up period.Increased serum IL-18 could be considered as a predictor of cardiocerebral vascular events in dialysis patients. It is noteworthy that various comorbidities might interfere the expression of IL-18; therefore, further validation study is required to incorporate IL-18 in clinical use.

Cholesterol Metabolism in CKD

Patients with chronic kidney disease (CKD) have a substantial risk of developing coronary artery disease. Traditional cardiovascular disease (CVD) risk factors such as hypertension and hyperlipidemia do not adequately explain the high prevalence of CVD in CKD. Both CVD and CKD are inflammatory states and inflammation adversely affects lipid balance. Dyslipidemia in CKD is characterized by elevated triglyceride levels and high-density lipoprotein levels that are both decreased and dysfunctional. This dysfunctional high-density lipoprotein becomes proinflammatory and loses its atheroprotective ability to promote cholesterol efflux from cells, including lipid-overloaded macrophages in the arterial wall. Elevated triglyceride levels result primarily from defective clearance. The weak association between low-density lipoprotein cholesterol level and coronary risk in CKD has led to controversy over the usefulness of statin therapy. This review examines disrupted cholesterol transport in CKD, presenting both clinical and preclinical evidence of the effect of the uremic environment on vascular lipid accumulation. Preventative and treatment strategies are explored.

A pilot randomized crossover trial assessing the safety and short-term effects of pomegranate supplementation in hemodialysis patients

OBJECTIVE

Oxidative stress and systemic inflammation are highly prevalent in patients undergoing maintenance hemodialysis (MHD) and are linked to excess cardiovascular risk. This study examined whether short-term supplementation with pomegranate juice and extract is safe and well tolerated by MHD patients. The secondary aim was to assess the effect of pomegranate supplementation on oxidative stress, systemic inflammation, monocyte function, and blood pressure.

DESIGN

Prospective, randomized, crossover, pilot clinical trial (NCT01562340).

SETTING

The study was conducted from March to October 2012 in outpatient dialysis facilities in the Seattle metropolitan area.

SUBJECTS

Twenty-four patients undergoing MHD (men, 64%; mean age, 61 ± 14 years) were randomly assigned to receive pomegranate juice or extract during a 4-week intervention period. After a washout period, all patients received the alternative treatment during a second 4-week intervention period.

INTERVENTION

Patients assigned to receive pomegranate juice received 100 mL of juice before each dialysis session. Patients assigned to receive pomegranate extract were given 1,050 mg of extract daily.

MAIN OUTCOME MEASURES

The main outcome measures were safety and tolerability of pomegranate juice and extract. Additional secondary outcomes assessed included serum lipids, laboratory biomarkers of inflammation (C-reactive protein and interleukin 6) and oxidative stress (plasma F2 isoprostanes and isofurans), monocyte cytokine production, and predialysis blood pressure.

RESULTS

Both pomegranate juice and extract were safe and well tolerated by study participants. Over the study period, neither treatment had a significant effect on lipid profiles, plasma C-reactive protein, interleukin 6, F2-isoprostane or isofuran concentrations, predialysis systolic or diastolic blood pressure nor changed the levels of monocyte cytokine production.

CONCLUSIONS

Both pomegranate juice and extract are safe and well tolerated by patients undergoing MHD but do not influence markers of inflammation or oxidative stress nor affect predialysis blood pressure.

Cardiovascular co-morbidity in chronic kidney disease: Current knowledge and future research needs

Chronic kidney disease (CKD) is recognised as a health concern globally and leads to high rates of morbidity, mortality and healthcare expenditure. CKD is itself an independent risk factor for unfavorable health outcomes that include cardiovascular disease (CVD). Coronary artery disease is the primary type of CVD in CKD patients and a significant cause of death among renal transplant patients. Traditional and non-traditional risk factors for CVD exist in patients with CKD. Traditional factors include smoking, hypertension, dyslipidemia and diabetes which are highly prevalent in CKD patients. Non-traditional risk factors of CKD are mainly uraemia-specific and increase in prevalence as kidney function declines. Some examples of uraemia-specific risk factors that have been well documented include low levels of haemoglobin, albuminuria, and abnormal bone and mineral metabolism. Therapeutic interventions targeted at more traditional risk factors which contribute to CVD, have not had the desired effect on lowering CVD events and mortality in those suffering with CKD. Future research is warranted to delineate clear evidence to the benefit of modifying non-traditional risk factors.

The deleterious effects of arteriovenous fistula-creation on the cardiovascular system: a longitudinal magnetic resonance imaging study

Aim

Arteriovenous fistula-formation remains critical for the provision of hemodialysis in end-stage renal failure patients. Its creation results in a significant increase in cardiac output, with resultant alterations in cardiac stroke volume, systemic blood flow, and vascular resistance. The impact of fistula-formation on cardiac and vascular structure and function has not yet been evaluated via “gold standard” imaging techniques in the modern era of end-stage renal failure care.

Methods

A total of 24 patients with stage 5 chronic kidney disease undergoing fistula-creation were studied in a single-arm pilot study. Cardiovascular magnetic resonance imaging was undertaken at baseline, and prior to and 6 months following fistula-creation. This gold standard imaging modality was used to evaluate, via standard brachial flow-mediated techniques, cardiac structure and function, aortic distensibility, and endothelial function.

Results

At follow up, left ventricular ejection fraction remained unchanged, while mean cardiac output increased by 25.0% (P<0.0001). Significant increases in left and right ventricular end-systolic volumes (21% [P=0.014] and 18% [P<0.01]), left and right atrial area (11% [P<0.01] and 9% [P<0.01]), and left ventricular mass were observed (12.7% increase) (P<0.01). Endothelial-dependent vasodilation was significantly decreased at follow up (9.0%±9% vs 3.0%±6%) (P=0.01). No significant change in aortic distensibility was identified.

Conclusion

In patients with end-stage renal failure, fistula-formation is associated with an increase in cardiac output, dilation of all cardiac chambers and deterioration in endothelial function.

Sevelamer revisited: pleiotropic effects on endothelial and cardiovascular risk factors in chronic kidney disease and end-stage renal disease

Endothelial dysfunction underlies multiple cardiovascular consequences of chronic kidney disease (CKD) and antecedent diabetes or hypertension. Endothelial insults in CKD or end-stage renal disease (ESRD) patients include uremic toxins, serum uric acid, hyperphosphatemia, reactive oxygen species, and advanced glycation endproducts (AGEs). Sevelamer carbonate, a calcium-free intestinally nonabsorbed polymer, is approved for hyperphosphatemic dialysis patients in the US and hyperphosphatemic stage 3-5 CKD patients in many other countries. Sevelamer has been observed investigationally to reduce absorption of AGEs, bacterial toxins, and bile acids, suggesting that it may reduce inflammatory, oxidative, and atherogenic stimuli in addition to its on-label action of lowering serum phosphate. Some studies also suggest that noncalcium binders may contribute less to vascular calcification than calcium-based binders. Exploratory sevelamer carbonate use in patients with stages 2-4 diabetic CKD significantly reduced HbA1c, AGEs, fibroblast growth factor (FGF)-23, and total and low-density lipoprotein (LDL) cholesterol versus calcium carbonate; inflammatory markers decreased and defenses against AGEs increased. Sevelamer has also been observed to reduce circulating FGF-23, potentially reducing risk of left ventricular hypertrophy. Sevelamer but not calcium-based binders in exploratory studies increases flow-mediated vasodilation, a marker of improved endothelial function, in patients with CKD. In contrast, lanthanum carbonate and calcium carbonate effects on FMV did not differ in hemodialysis recipients. The recent independent-CKD randomized trial compared sevelamer versus calcium carbonate in predialysis CKD patients (investigational in the US, on-label in European participants); sevelamer reduced 36-month mortality and the composite endpoint of mortality or dialysis inception. Similarly, independent-HD in incident dialysis patients showed improved survival with 24 months of sevelamer versus calcium-based binders. This review discusses recent exploratory evidence for pleiotropic effects of sevelamer on endothelial function in CKD or ESRD. Endothelial effects of sevelamer may contribute mechanistically to the improved survival observed in some studies of CKD and ESRD patients.