Contrast-Induced Acute Kidney Injury in Patients Undergoing Carotid Artery Stenting: An Underestimated Issue

C-Reactive Protein to Albumin Ratio as a Predictor of Contrast-Induced Nephropathy After Carotid Angiography

This study evaluated the role of the C-reactive protein (CRP)/albumin ratio (CAR) in estimating the probability of occurring contrast-induced nephropathy (CIN) after carotid artery angiography (CAAG). Patients (n = 410) who had CAAG for carotid artery stenosis (CAS) were included in this study. A spike in serum creatinine was used to define CIN within 72 h of the procedure (>.5 mg/dL or >25% above baseline). CAR was calculated by dividing the CRP by the albumin level. Patients with CIN had higher numbers of white blood cells (P = .002), numbers of neutrophils (P = .007), neutrophil-lymphocyte ratios (P = .026), high-sensitivity CRP levels (P < .001), and CAR levels (P < .001) than those without CIN. They were also older (P < .001) and more likely to have diabetes mellitus (P = .006) and hypertension (P = .016). According to receiver operator characteristic curve (ROC) analysis, the CAR value has a 75% sensitivity and a 68% specificity for identifying CIN at a cutoff of 1.8. Also, NLR and CRP predicted CIN with 71% sensitivity and 67% specificity, 71% sensitivity and 66% specificity at the best cutoff values of 1.96 and 7.91, respectively. According the present study, in patients with CAS, the development of CIN after CAAG is independently correlated with CAR at admission.

A Novel Predictor of Contrast-Induced Nephropathy in Patients With Carotid Artery Disease; the Systemic Immune Inflammation Index

Contrast-induced nephropathy (CIN) is associated with increased mortality and morbidity. The present study investigated the role of systemic immune inflammation index (SII) in predicting the risk of developing CIN after carotid artery angiography (CAAG). This study included 262 patients who underwent CAAG for symptomatic carotid artery stenosis (CAS). Simultaneous carotid stenting was applied to 232 of these patients. CIN was defined as an increase in serum creatinine level ≥.5 mg/dL or ≥25% above baseline within 72 hours after the procedure. The SII score was calculated as platelet × neutrophil/lymphocyte counts. Patients who developed CIN, had higher glucose (P = .009), total cholesterol (P < .001), low density lipoprotein cholesterol (<.001), and high sensitivity C-reactive protein (P = .001) levels, as well as greater neutrophil counts (P < .001), platelet counts (P < .001), neutrophil-lymphocyte ratio (P < .001), and SII score (P < .001) than those who did not develop CIN. The Receiver Operating Characteristic analysis showed that at a cutoff of 519.9, the SII exhibited 80% sensitivity and 64% specificity for detecting CIN. SII levels on admission were independently associated with CIN development after CAAG in patients with CAS.

Narrative Review of Carotid disease and the kidney

Patients with chronic kidney disease (CKD) have an increased cardiovascular (CV) risk that is only in part explained by established risk factors. Carotid arteriosclerosis and atherosclerosis are increased in CKD, play a role in the causation of CV disease in these patients and can affect the progression of renal disease. The arterial stiffening process is evident even in CKD patients with a very mild reduction of glomerular filtration rate (GFR) whereas arterial thickening is evident in more advanced stages. Possible mechanisms include functional and structural alterations of the arterial wall. Arterial stiffness can mediate the effect of CKD on target organs (i.e., brain, kidney and heart). In this review we discuss the arterial phenotype of patients with CKD. This is characterized by increased common carotid artery stiffness and outward remodeling (enlargement and thickening of the arterial wall) and a normal/reduced stiffness paired with an inward remodeling (narrowing of the arterial wall) of muscular arteries. We also discuss the consequences of carotid dysfunction, including the involvement of large elastic arteries stiffness on ventricular-vascular coupling, the mechanisms linking carotid stiffening and increased cardio- and cerebrovascular risk in CKD patients, and the therapeutic options to improve carotid function.

Contrast-induced nephropathy in non-cardiac vascular procedures, a narrative review: Part 2

This is Part 2 of a narrative review summarizing the literature on CIN after non-cardiac vascular diagnostic or therapeutic procedures, focusing on peripheral artery disease (PAD) and renal artery stenosis (RAS). Part 1 discussed CIN in relation to aortic aneurysms and carotid stenosis. We comment on the incidence, biomarkers, risk factors, and consequences of CIN in patients with PAD or RAS, as well as on strategies to prevent CIN. Future perspectives in the field of CIN in relation to non-cardiac vascular procedures are also considered.

Contrast-induced nephropathy in non-cardiac vascular procedures, a narrative review: Part 1

Contrast-induced nephropathy (CIN) is an important complication of iodinated contrast medium (CM) administration, which is associated with both short- and long-term adverse outcomes (e.g., cardiorenal events, longer hospital stay, and mortality). CIN has been mainly studied in relation to cardiac procedures, but it can also occur following non-cardiac vascular interventions. This is Part 1 of a narrative review summarizing the available literature on CIN after non-cardiac vascular diagnostic or therapeutic procedures for aortic aneurysm and carotid stenosis. We discuss the definition, pathophysiology, incidence, risk factors, biomarkers, and consequences of CIN in these settings, as well as preventive strategies and alternatives to limit iodinated CM use. Physicians and vascular surgeons should be aware of CM-related adverse events and the potential strategies to avoid them. Clearly, more research in this important field is required.

The association between neutrophil-to-lymphocyte ratio and contrast-induced acute kidney injury in patients with carotid artery stenting

OBJECTIVES

Contrast-induced acute kidney injury (CI-AKI) is a life-threatening complication that leads to comorbidities and prolonged hospital stay lengths in the setting of peripheral interventions. The presence of some CI-AKI risk factors has already been investigated. In this study, we evaluated the predictors of CI-AKI after carotid artery stenting.

METHODS

A total of 389 patients with 50% to 99% carotid artery stenosis who underwent carotid artery stenting were included in this study. Patients were grouped according to CI-AKI status.

RESULTS

CI-AKI developed in 26 (6.6%) patients. Age, baseline creatinine level, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were higher and estimated glomerular filtration rate, haemoglobin and lymphocyte count were lower in CI-AKI patients. In the multivariate regression analysis, the neutrophil-to-lymphocyte ratio triggered a 1.39- to 2.63-fold increase in the risk of CI-AKI onset (p < 0.001).

CONCLUSIONS

The neutrophil-to-lymphocyte ratio may be a significant predictor of CI-AKI in patients with carotid artery stenting and higher neutrophil-to-lymphocyte ratio values may be independently associated with CI-AKI.

Cholesterol, carotid artery disease and stroke: what the vascular specialist needs to know

Hypercholesterolemia is a risk factor for carotid artery stenosis and stroke. Statins are the main drugs for the management of hypercholesterolemia and they are strongly recommended by international guidelines for the management of vascular patients. The present review will focus on the associations between cholesterol, carotid artery stenosis and stroke and will cover several topics, including the conservative and perioperative/periprocedural management of carotid patients, the effect of statins on contrast-induced nephropathy developing after endovascular carotid interventions, the role of statin loading prior to endovascular procedures, as well as the indirect beneficial effects of statin treatment on renal function. It will also discuss the topics of statin intolerance and alternative cholesterol-lowering options for statin-intolerant vascular patients. Cholesterol levels play a prognostic role in carotid patients with regards to both short- and long-term stroke and mortality rates. Physicians should keep in mind the pivotal role of cholesterol levels in determining cardiovascular outcomes and the pleiotropic beneficial effects associated with statin use and should not miss the opportunity for cardiovascular risk reduction with aggressive statin treatment.

Hyperbaric Oxygen Therapy and Vascular Complications in Diabetes Mellitus

Vascular complications in patients with diabetes mellitus (DM) are common. Since impaired oxygen balance in plasma plays an important role in the pathogenesis of chronic DM-associated complications, the administration of hyperbaric oxygen therapy (HBOT) has been recommended to influence development of vascular complications. Hyperbaric oxygen therapy involves inhalation of 100% oxygen under elevated pressure from 1.6 to 2.8 absolute atmospheres in hyperbaric chambers. Hyperbaric oxygen therapy increases plasma oxygen solubility, contributing to better oxygen diffusion to distant tissues and preservation of the viability of tissues reversibly damaged by atherosclerosis-induced ischemia, along with microcirculation restoration. Hyperbaric oxygen therapy exerts antiatherogenic, antioxidant, and cardioprotective effects by altering the level and composition of plasma fatty acids and also by promoting signal transduction through membranes, which are impaired by hyperglycemia and hypoxia. In addition, HBOT affects molecules involved in the regulation of nitric oxide synthesis and in that way exerts anti-inflammatory and angiogenic effects in patients with DM. In this review, we explore the recent literature related to the effects of HBOT on DM-related vascular complications.

Diabetes and carotid artery disease: a narrative review

Diabetes mellitus (DM) has been linked to an increased prevalence and severity of carotid artery disease, as well as polyvascular disease. Carotid disease is also associated with obesity and abnormal peri-organ and intra-organ fat (APIFat) deposition (i.e., excess fat accumulation in several organs such as the liver, heart and vessels). In turn, DM is associated with APIFat. The coexistence of these comorbidities confers a greater risk of vascular events. Clinicians should also consider that carotid bruits may predict cardiovascular risk. DM has been related to a greater risk of adverse outcomes after carotid endarterectomy or stenting. Whether modifying risk factors (e.g., glycaemia and dyslipidaemia) in DM patients can improve the outcomes of these procedures needs to be established. Furthermore, DM is a risk factor for contrast-induced acute kidney injury (CI-AKI). The latter should be recorded in DM patients undergoing carotid stenting since it can influence both short- and long-term outcomes. From a pathophysiological perspective, functional changes in the carotid artery may precede morphological ones. Furthermore, carotid plaque characteristics are increasingly being studied in terms of vascular risk stratification and monitoring short-term changes attributed to treatment. The present narrative review discusses the recent (2019) literature on the associations between DM and carotid artery disease. Physicians and vascular surgeons looking after patients with carotid disease and DM should consider these links that may influence outcomes. Further research in this field is also needed to optimise the treatment of such patients.

Renal Dysfunction Following Elective Endovascular Aortic Aneurysm Repair

Abdominal aortic aneurysm (AAA) is a degenerative disease of the aortic wall with potentially fatal complications. Open repair (OR) was considered the gold standard, until the emergence of endovascular aneurysm repair (EVAR), which is less invasive and equally (if not more) effective. As the popularity of endovascular procedures grows, related complications become more evident, with kidney damage being one of them. Although acute kidney injury (AKI) following EVAR is relatively common, its true incidence is still uncertain. Also, there is insufficient data concerning long-term renal outcomes after EVAR, especially with repeated contrast agent exposure. Despite the lack of firm evidence on the effectiveness of individual strategies, it is evident that prevention of AKI following EVAR requires a multifactorial approach. This review focuses on recent findings based on human studies regarding the current evidence of renal impairment after EVAR, its quantification and strategies for its prevention.

Rationale for screening selected patients for asymptomatic carotid artery stenosis

Stroke is a leading cause of death and disability worldwide. Approximately 15% of all first-ever strokes occur due to atheroembolism from a previously undetected/untreated asymptomatic carotid stenosis (ACS). Despite that, international guidelines do not recommend screening for ACS. The rationale for not recommending screening include: (a) the harm associated with screening, (b) the questionable clinical benefit associated with surgery, (c) the lack of proven reduction in the risk of stroke, (d) the large number of false positive/false negative tests, and (e) the cost-effectiveness of such screening programs. A critical analysis of each of these arguments is presented. Patients with ACS have a very high risk of all-cause and cardiac mortality. Detection of ACS should not be viewed as an indication for surgery, but rather as an opportunity to implement best medical treatment (BMT) and lifestyle changes to prevent not only strokes, but also cardiac events. The implementation of screening programs for abdominal aortic aneurysms (AAAs) has led to a considerable reduction in the number of ruptured AAAs and AAA-related deaths. Similarly, screening high-risk individuals for ACS would enable timely identification of patients with ACS and implementation of BMT and lifestyle measures to prevent future strokes and cardiac events.

Non-Invasive Imaging for Evaluating Cardiovascular Involvement in Patients with Primary and Lupus Nephritis

Background:

Evidence suggests that proteinuric diseases, such as primary or secondary glomerulonephritis, increase cardiovascular risk, but few studies confirmed this association.

Methods:

This is a cross-sectional, observational study on 32 patients, 17 with Primary Glomerulonephritis (PG) and 15 with Lupus Glomerulonephritis (LG). The control group consisted of 32 healthy individuals. Intima-media thickness (IMT) of the left common carotid artery, carotid bifurcation and internal carotid artery was measured by ultrasound. Left ventricular myocardial deformation was assessed by the use of the Global Circumferential Strain (GCS) and the Global Longitudinal Strain (GLS) following 2-Dimensional (2D) echocardiography in all participants.

Results:

Patients with glomerulonephritis in both groups showed significantly lower GLS compared with controls (p=0.0005). There was also a significant difference in common carotid IMT values between the LG and GP group (0.45±0.09 vs. 0.58±0.17 mm, respectively; p=0.01), but there was no difference with the control group. In patient group (n=32), a significantly positive correlation was observed between C-reactive protein and proteinuria (r=0.98; p<0.0001), whereas negative correlations were found between common carotid IMT and creatinine clearance (r=-0.97; p<0.0001) and between carotid bifurcation IMT and phosphate levels (r=-0.97; p<0.0001)

Conclusion:

Subclinical systolic myocardial dysfunction is present early in the course of glomerular disease. The use of 2D GLS revealed that LG and PG patients with no cardiovascular symptoms or history and a preserved left ventricle ejection fraction on conventional echocardiography had subclinical reduction in LV global longitudinal systolic function compared with controls.

Clinical efficacy and safety of statin treatment after carotid artery stenting

Objective: The randomized controlled trail was carried out to investigate the influence of statin pre-treatment on clinical efficacy of carotid artery stenting (CAS). Methods: 160 eligible patients were randomly divided into statin group (n = 82) and control group (n = 78). The patients in statin group received 40 mg atorvastatin daily 7 days before operation. Major endpoints included transient ischemic attack (TIA), stroke, death, myocardial infarction (MI), and other cardiac adverse events within 30 days after CAS. Results: Preoperative baseline information was similar between the statin and control groups (p > 0.05 for all). Within 48 h after operation, the occurrence rate of CIN (3.66% vs 8.97%, p = .019) and new infarction (4.88% vs. 14.10%, p = .045) were significantly lower in statin group than in control group. 30 days after CAS, the incidences of TIA (12.20% vs. 26.92%, p = .018), ischemic stroke (6.10% vs. 16.67%, p = .034), and other cardiac complications (7.32% vs. 19.23%, p = .026) were also significantly lower in statin group, than in the control group. Multiple analysis demonstrated that statin use exerted protective effect against ischemic stroke (OR = 0.038, 95% CI = 0.003-0.543, p = .016) and other cardiac complications (OR = 0.208, 95%CI = 0.063-0.694, p = .011). Conclusion: Pre-treatment with statin is an effective and safe strategy to prevent from perioperative complications and to improve postoperative outcomes in patients undergoing CAS.

Lipids: a personal view of the past decade

The past decade has witnessed considerable progress in the field of lipids. New drugs have been "rapidly" developed and some of these drugs have already been evaluated in event-based large trials. This evidence has led to the guidelines recommending new, more aggressive treatment goals for low-density lipoprotein cholesterol (LDL-C) levels. Although LDL-C remains the principal goal for cardiovascular disease (CVD) risk reduction, there has also been considerable interest in other lipid variables, such as high-density lipoprotein cholesterol, triglycerides, and lipoprotein(a). Statin intolerance is now considered a very important topic in daily clinical practice. This has resulted in more attention focusing on non-statin drugs [e.g., ezetimibe and proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors] and statin-related side effects. The latter mainly involve muscles, but there is also a need to consider other adverse effects associated with statin use (e.g., new onset diabetes). New specific areas of statin use have attracted interest. For example, statin-loading before procedures (e.g., coronary stenting), the prevention of stroke, and the treatment of non-alcoholic fatty liver disease (NAFLD). Statins will remain the most widely used drugs to treat dyslipidaemia and decrease CVD risk. However, we also need to briefly consider some other lipid-lowering drugs, including those that may become available in the future.

The Ratio of Fibrinogen to Albumin as a Predictor of Contrast-Induced Nephropathy After Carotid Angiography

Contrast-induced nephropathy (CIN) is acute kidney failure that occurs after exposure to contrast agent. There is no sensitive biomarker to predict the development of CIN. In a retrospective study, we investigated the predictive value of the fibrinogen to albumin ratio (FAR) to determine the risk of CIN in patients (N = 246) who underwent carotid angiography. Contrast-induced nephropathy was defined as a 0.5 mg/dL or 25% increase in serum creatinine levels 48 to 72 hours following exposure to a radiocontrast agent. Patients were grouped according to whether they developed CIN or not, that is, CIN(-) and CIN(+) groups, respectively. Contrast-induced nephropathy developed in 39 (15.8%) of all the patients. The fibrinogen levels, neutrophil to lymphocyte ratio (NLR), and FAR in the CIN (+) group were higher than in the CIN (-) group ( P < .001). Multivariate analysis showed that age, diabetes, NLR, platelet-lymphocyte ratio, and FAR were independent risk factors for CIN. The area under the curve (AUC) of FAR was 0.800 for the prediction of CIN, and the best cutoff value was 57.4 with sensitivity, specificity, positive predictive value, and negative predictive value of 74.4%, 60.8%, 26.4%, and 92.7%, respectively. The FAR may be useful as a predictor of CIN.

Mitochondrial energetics in the kidney

The kidney requires a large number of mitochondria to remove waste from the blood and regulate fluid and electrolyte balance. Mitochondria provide the energy to drive these important functions and can adapt to different metabolic conditions through a number of signalling pathways (for example, mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) pathways) that activate the transcriptional co-activator peroxisome proliferator-activated receptor-γ co-activator 1α (PGC1α), and by balancing mitochondrial dynamics and energetics to maintain mitochondrial homeostasis. Mitochondrial dysfunction leads to a decrease in ATP production, alterations in cellular functions and structure, and the loss of renal function. Persistent mitochondrial dysfunction has a role in the early stages and progression of renal diseases, such as acute kidney injury (AKI) and diabetic nephropathy, as it disrupts mitochondrial homeostasis and thus normal kidney function. Improving mitochondrial homeostasis and function has the potential to restore renal function, and administering compounds that stimulate mitochondrial biogenesis can restore mitochondrial and renal function in mouse models of AKI and diabetes mellitus. Furthermore, inhibiting the fission protein dynamin 1-like protein (DRP1) might ameliorate ischaemic renal injury by blocking mitochondrial fission.