Geographic variability and operator trends of transcatheter edge-to-edge repair in the United States.

BACKGROUNDS: Transcatheter edge-to-edge repair (TEER) devices are used for primary mitral regurgitation (MR) and secondary MR. Despite the growing use of TEER devices, there have not been many studies on operator experience or procedure volumes by state. AIMS: We aimed to investigate nationwide operator volume trends and geographic variation in access to TEER. METHODS: The United States Center for Medicare and Medicaid Services (CMS) National Medicare Provider Utilization and Payment Database (MPUPD) was analyzed between 2015 and 2020 for initial TEER procedures. RESULTS: Procedure volume and total operators increased yearly from 2015 to 2019 but declined in 2020. Mean annual procedure volume per operator varied significantly by state, between 0 in multiple states and 35 in North Dakota. In 2019, 994 unique operators were identified, with 295 operators documented performing 10 or more procedures (29.68%). Operators performing 10 or more TEER procedures provided 68.46% of all operations in 2019, averaging 20.94 procedures per operator. CONCLUSIONS: TEER procedures are becoming increasingly common as more operators are being trained. However, significant variability exists in the procedural volume per operator.

Clinical characteristics and outcomes of patients admitted to hospitals for posterior reversible encephalopathy syndrome: a retrospective cohort study.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is usually a benign, yet underdiagnosed clinical condition associated with subacute to acute neurological manifestations primarily affecting white matter. PRES is reversible when recognized promptly and treated early by removal of the insulting factor; however, can lead to irreversible and life-threatening complications such as cerebral hemorrhage, cerebellar herniation, and refractory status epilepticus. METHODS: We utilized the National Inpatient Sample database provided by the Healthcare Cost and Utilization Project (HCUP-NIS) 2017 to investigate the demographic variables (age, sex, and race) for patients with PRES, concomitant comorbidities and conditions, inpatient complications, inpatient mortality, length of stay (LOS), and disposition. RESULTS: A total of 635 admissions for patients aged 18 years or older with PRES were identified. The mean age was 57.2 ± 0.6 years old with most encounters for female patients (71.7%, n = 455) and white as the most prevalent race. Half the patients in our study presented with seizures (50.1%, n = 318), sixty-three patients (9.9%) presented with vision loss, and sixty-four patients (10.1%) had speech difficulty. In addition, 45.5% of patients had hypertensive crisis (n = 289). 2.2% of hospitalizations had death as the outcome (n = 14). The mean LOS was 8.2 (±0.3) days, and the mean total charges were $92,503 (±$5758). Inpatient mortality differed between males and females (1.7% vs. 2.4%) and by race (3.6% in black vs. 1.8% in white) but was ultimately determined to be not statistically significant. Most patients who present with vision disturbance have a high risk of intracranial hemorrhage. Furthermore, end-stage renal disease, atrial fibrillation, and malignancy seemed to be linked with a very high risk of mortality. CONCLUSION: PRES, formerly known as reversible posterior leukoencephalopathy, is a neurological disorder with variable presenting symptoms. Although it is generally a reversible condition, some patients suffer significant morbidity and even mortality. To the best of our knowledge, this is the largest retrospective cohort of PRES admissions that raises clinician awareness of clinical characteristics and outcomes of this syndrome.

Post-traumatic thrombotic microangiopathy: What trauma surgeons need to know?

Thrombotic microangiopathy (TMA) is characterized by systemic microvascular thrombosis, target organ injury, anemia and thrombocytopenia. Thrombotic thrombocytopenic purpura, atypical hemolytic uremic syndrome and Shiga toxin E-coli-related hemolytic uremic syndrome are the three common forms of TMAs. Traditionally, TMA is encountered during pregnancy/postpartum period, malignant hypertension, systemic infections, malignancies, autoimmune disorders, etc. Recently, the patients presenting with trauma have been reported to suffer from TMA. TMA carries a high morbidity and mortality, and demands a prompt recognition and early intervention to limit the target organ injury. Because trauma surgeons are the first line of defense for patients presenting with trauma, the prompt recognition of TMA for these experts is critically important. Early treatment of post-traumatic TMA can help improve the patient outcomes, if the diagnosis is made early. The treatment of TMA is also different from acute blood loss anemia namely in that plasmapheresis is recommended rather than platelet transfusion. This article familiarizes trauma surgeons with TMA encountered in the context of trauma. Besides, it provides a simplified approach to establishing the diagnosis of TMA. Because trauma patients can require multiple transfusions, the development of disseminated intravascular coagulation must be considered. Therefore, the article also provides different features of disseminated intravascular coagulation and TMA. Finally, the article suggests practical points that can be readily applied to the management of these patients.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update.

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Innovations in vascular access for hemodialysis.

Worldwide, hemodialysis remains the prevalent dialysis modality for more than 2 million patients who require well-functioning vascular access for this procedure. Creation of an arteriovenous fistula for long-term hemodialysis was the first innovation since the Scribner shunt and was followed by the development of an arteriovenous graft and catheter. Bioengineered vessels were developed during the last century, but this field has been energized by recent technology relating to the creation of human vessels. Novel endovascular techniques for creating an arteriovenous fistula may resolve some of the logistical issues involved in obtaining a timely arteriovenous fistula. Treatment of access stenosis, infection, and thrombosis has remained suboptimal, and innovative technologies are evolving. Many new approaches are now targeting the biological and mechanical aspects of vascular access, such as creation and maturation of arterial and venous anastomoses, development of a biological conduit for outflow, and negotiating the problems of central vein stenosis. Importantly, processes of access care that have long focused on arteriovenous fistulas are now recognizing the new paradigm, providing a complementary niche to arteriovenous grafts and dialysis catheters in the algorithm for individualized access placement. Cumulatively, to the credit of the multidisciplinary team approach, the long overdue focus on the very existential issue of vascular access for hemodialysis is being approached with newfound evidence-based enthusiasm as the vexing challenges related to regulations and reimbursement in hemodialysis persist. Patient choice and experience, often missed and ignored in the challenging management of an end-stage organ failure, need to stay central as we focus on patient-centered care of vascular access.

Best Vascular Access in the Elderly: Time for Innovation?

BACKGROUND: Conflicting data continue to surround the optimal dialysis access for the elderly. Many propose that catheters are the best option for this population; others emphasize the creation of an arteriovenous fistula. SUMMARY: While an arteriovenous access is the best available access, it has a high early failure rate, particularly in the elderly. However, significant differences exist in forearm (men ≥65 years ~70%; women ≥65 years ~80%) versus upper arm (men ≥65 years ~40%; women ≥65 years ~38%) fistula failure rates in the elderly, with upper arm having much lower failure rates. Two percutaneous innovative techniques that successfully establish fistulas at the upper arm using proximal radial/ulnar -artery as the inflow have been recently introduced. These procedures have been successfully performed in the elderly. Importantly, these techniques bypass the open surgical exploration and as such avoid the surgical manipulation of the juxta-anastomotic region (a common cause for the development of juxta-anastomotic stenosis and early fistula failure). Key Message: This article discusses the arteriovenous fistula creation in the elderly, highlights the factors necessary for successful fistula creation, and describes the 2 innovative techniques that can be used to provide a robust platform for successful fistula creation in this population.

Vascular access of last resort.

Exhausted vasculature is not uncommon in patients receiving long-term hemodialysis treatment. Certain patients exhaust their peripheral veins and do not retain the venous capital necessary for fistula creation. Others suffer from severe peripheral arterial disease and despite the presence of adequate venous capital are not able to receive an arteriovenous access successfully. Most importantly, in the case of occluded central veins, the creation of an arteriovenous access in the arms or thighs would be futile, even if peripheral veins and/or arteries were available. Because renal transplant is not readily available, such patients virtually face death in the absence of dialysis therapy. Hence, it is critically important that vascular access options be available to successfully receive renal replacement therapy. This article describes accesses of last resort and provides information vital to nephrologists for discussion with their patients and to surgeons in choosing an optimal option.

The Complications of Vascular Access in Hemodialysis.

Complications related to hemodialysis vascular access continue to have a major impact on morbidity and mortality. Vascular access dysfunction is the single most important factor that determines the quality of dialysis treatment. Vascular access stenosis is a common complication that develops in a great majority of patients with an arteriovenous access and leads to access dysfunction. By restricting luminal diameter, this complication leads to a reduction in blood flow and places the access at risk for thrombosis. Similarly, the development of catheter-related fibroepithelial sheath also causes catheter dysfunction with its detrimental effects on blood flow. In this article, we discuss the most common complications associated with dialysis access and provide therapeutic options to manage these problems.

The Hemoglobin Homolog Cytoglobin in Smooth Muscle Inhibits Apoptosis and Regulates Vascular Remodeling.

OBJECTIVE: The role of hemoglobin and myoglobin in the cardiovascular system is well established, yet other globins in this context are poorly characterized. Here, we examined the expression and function of cytoglobin (CYGB) during vascular injury. APPROACH AND RESULTS: We characterized CYGB content in intact vessels and primary vascular smooth muscle (VSM) cells and used 2 different vascular injury models to examine the functional significance of CYGB in vivo. We found that CYGB was strongly expressed in medial arterial VSM and human veins. In vitro and in vivo studies indicated that CYGB was lost after VSM cell dedifferentiation. In the rat balloon angioplasty model, site-targeted delivery of adenovirus encoding shRNA specific for CYGB prevented its reexpression and decreased neointima formation. Similarly, 4 weeks after complete ligation of the left common carotid, Cygb knockout mice displayed little to no evidence of neointimal hyperplasia in contrast to their wild-type littermates. Mechanistic studies in the rat indicated that this was primarily associated with increased medial cell loss, terminal uridine nick-end labeling staining, and caspase-3 activation, all indicative of prolonged apoptosis. In vitro, CYGB could be reexpressed after VSM stimulation with cytokines and hypoxia and loss of CYGB sensitized human and rat aortic VSM cells to apoptosis. This was reversed after antioxidant treatment or NOS2 (nitric oxide synthase 2) inhibition. CONCLUSIONS: These results indicate that CYGB is expressed in vessels primarily in differentiated medial VSM cells where it regulates neointima formation and inhibits apoptosis after injury.

Community acute kidney injury is associated with short- and long-term adverse outcomes in patients admitted with acute myocardial infarction
.

AIMS: The influence of community acute kidney injury on patients with myocardial infarction has not been explored. The Veterans Affair electronic health system was analyzed to test the hypothesis that patients who have myocardial infarction complicated by community acute kidney injury have higher short- and long-term mortality and cardiovascular outcomes than those who do not suffer acute kidney injury. MATERIALS AND METHODS: Odd ratios were calculated for in-hospital mortality. Cox proportional hazard model was used to assess hazard ratios for long-term mortality comparing patients with and without community acute kidney injury. Secondary outcomes included recurrent cardiovascular events including hospitalization for congestive heart failure, stroke, or repeat myocardial infarction. RESULTS: 10,689 patients were available for evaluation, 679 had community acute kidney injury and 10,010 with no acute kidney injury. Community acute kidney injury resulted in higher odds for inpatient mortality (odds ratio 5.87, p < 0.001), and adjusted hazard ratio for mortality at 5 years as compared to no acute kidney injury (hazard ratio 1.67, p < 0.001). No differences in cardiovascular outcomes were identified in Cox proportional hazard analysis. CONCLUSION: In patients with myocardial infarction, community acute kidney injury is associated with delays in or not receiving appropriate myocardial infarction related process of care measures. In addition it is an independent predictor of short- and long-term mortality.
.

Diagnosis and management of atherosclerotic cardiovascular disease in chronic kidney disease: a review.

Patients with chronic kidney disease (CKD) have a high prevalence of atherosclerotic cardiovascular disease, likely reflecting the presence of traditional risk factors. A greater distinguishing feature of atherosclerotic cardiovascular disease in CKD is the severity of the disease, which is reflective of an increase in inflammatory mediators and vascular calcification secondary to hyperparathyroidism of renal origin that are unique to patients with CKD. Additional components of atherosclerotic cardiovascular disease that are prominent in patients with CKD include microvascular disease and myocardial fibrosis. Therapeutic interventions that minimize cardiovascular events related to atherosclerotic cardiovascular disease in patients with CKD, as determined by well-designed clinical trials, are limited to statins. Data are lacking regarding other available therapeutic measures primarily due to exclusion of patients with CKD from major trials studying cardiovascular disease. Data from well-designed randomized controlled trials are needed to guide clinicians who care for this high-risk population in the management of atherosclerotic cardiovascular disease to improve clinical outcomes.

MYOSLID Is a Novel Serum Response Factor-Dependent Long Noncoding RNA That Amplifies the Vascular Smooth Muscle Differentiation Program.

OBJECTIVE: Long noncoding RNAs (lncRNA) represent a growing class of noncoding genes with diverse cellular functions. We previously reported on SENCR, an lncRNA that seems to support the vascular smooth muscle cell (VSMC) contractile phenotype. However, information about the VSMC-specific lncRNAs regulated by myocardin (MYOCD)/serum response factor, the master switch for VSMC differentiation, is unknown. APPROACH AND RESULTS: To define novel lncRNAs with functions related to VSMC differentiation, we performed RNA sequencing in human coronary artery SMCs that overexpress MYOCD. Several novel lncRNAs showed altered expression with MYOCD overexpression and one, named MYOcardin-induced Smooth muscle LncRNA, Inducer of Differentiation (MYOSLID), was activated by MYOCD and selectively expressed in VSMCs. MYOSLID was a direct transcriptional target of both MYOCD/serum response factor and transforming growth factor-ß/SMAD pathways. Functional studies revealed that MYOSLID promotes VSMC differentiation and inhibits VSMC proliferation. MYOSLID showed reduced expression in failed human arteriovenous fistula samples compared with healthy veins. Although MYOSLID did not affect gene expression of transcription factors, such as serum response factor and MYOCD, its depletion in VSMCs disrupted actin stress fiber formation and blocked nuclear translocation of MYOCD-related transcription factor A (MKL1). Finally, loss of MYOSLID abrogated transforming growth factor-ß1-induced SMAD2 phosphorylation. CONCLUSIONS: We have demonstrated that MYOSLID, the first human VSMC-selective and serum response factor/CArG-dependent lncRNA, is a novel modulator in amplifying the VSMC differentiation program, likely through feed-forward actions of both MKL1 and transforming growth factor-ß/SMAD pathways.

Is nephrology specialty at risk?

Interest in nephrology as a career choice has been steadily waning among internal medicine residents. This decline is reflected in a significant increment in unfilled fellowship training spots for several years. Interventional nephrology can help to reinvigorate an interest in nephrology as a whole.

Hand Ischemia in a Patient With an Arteriovenous Fistula.

An ischemic digit causes significant morbidity due to its associated discomfort and potential for tissue necrosis. Historically, when this phenomenon was peripheral to an ipsilateral arteriovenous access in a hemodialysis patient, it was called "steal syndrome" and was usually treated with access ligation, resulting in loss of the access. We present a dialysis patient with hand pain due to ischemia that was referred for access ligation. Instead, a minimally invasive banding procedure was performed that resulted in access salvage and resolution of symptoms. We present images and a discussion of the diagnosis and treatment of distal hypoperfusion ischemia syndrome in this Imaging Teaching Case.

Atypical Hemolytic-Uremic Syndrome: A Clinical Review.

Atypical hemolytic-uremic syndrome (HUS) is a rare life-threatening disorder characterized by microangiopathic hemolytic anemia, thrombocytopenia, and ischemic injury to organs, especially the kidneys. Microvascular injury and thrombosis are the dominant histologic findings. Complement activation through the alternative pathway plays a critical role in the pathogenesis of atypical HUS. Genetic abnormalities involving complement regulatory proteins and complement components form the molecular basis for complement activation. Endothelial cell dysfunction, probably because of the effects of complement activation, is an intermediate stage in the pathophysiologic cascade. Atypical HUS has a grave prognosis. Although mortality approaches 25% during the acute phase, end-stage renal disease develops in nearly half of patients within a year. Atypical HUS has a high recurrence rate after renal transplantation, and recurrent disease often leads to graft loss. Plasma therapy in the form of plasma exchange or infusion has remained the standard treatment for atypical HUS. However, many patients do not respond to plasma therapy and some require prolonged treatment. Approved by the Food and Drug Administration in the treatment of atypical HUS, eculizumab is a humanized monoclonal antibody that blocks cleavage of complement C5 into biologically active mediators of inflammation and cytolysis. Although case reports have shown the efficacy of eculizumab, randomized clinical trials are lacking. Therapeutic strategies targeting endothelial cells have demonstrated promising results in experimental settings. Therefore, inhibitors of angiotensin-converting enzyme, HMG-CoA reductase, and xanthine oxidase as well as antioxidants, such as ascorbic acid, may have salutary effects in patients with atypical HUS.

Community-acquired acute kidney injury: A challenge and opportunity for primary care in kidney health.

Community-acquired acute kidney injury (CA-AKI) has been found to be a common event in the population. Current incidence estimates are not available, but evaluations of severe elevations in serum creatinine indicate that incidence can be as high as 989 cases per million population in those older than 80 years. Data on risk factors are limited, but older age and higher comorbid illness burden, especially diabetes and cardiovascular disease, seem to be more common in patients who suffer CA-AKI. In addition to being more common than hospital-acquired AKI, the long-term sequelae of CA-AKI seem to be just as severe, including renal disease progression and mortality. Efforts to better understand the aetiology of CA-AKI and how ultimately to prevent the development of this condition will need to be taken. In the meantime, a concerted effort by general internists and nephrologists will be needed to prevent CA-AKI in the highest risk patients and thus limit the poor outcomes associated with this entity.

Effect of extended-release niacin on cardiovascular events and kidney function in chronic kidney disease: a post hoc analysis of the AIM-HIGH trial.

Chronic kidney disease (CKD) in patients is strongly associated with cardiovascular morbidity and mortality, and prevalent abnormal lipid metabolism. The AIM-HIGH trial examined the benefits of adding extended-release niacin (ERN) to simvastatin in patients with established coronary heart disease. Here we conducted a post hoc analysis of the AIM-HIGH trial examining whether participants derived cardiovascular or renal benefits when stratified by renal function. Of 3414 participants, 505 had stage 3 CKD at baseline. Among the CKD subset, demographics and cardiovascular disease (CVD) risk factors were well balanced in the ERN and placebo arms. Compared with placebo, CKD participants receiving ERN had a significant decrease in triglycerides by a median of 59.0 mg/dl, and high-density lipoprotein cholesterol significantly increased by a mean of 11.3 mg/dl over a mean follow-up of 3 years. CVD events were similar between CKD participants in both arms. However, all-cause mortality was significantly higher in the ERN group (hazard ratio of 1.73). Mean change in eGFR among ERN-treated CKD participants was not significantly different between study arms. Thus, among AIM-HIGH participants with CKD, the addition of ERN to simvastatin for secondary prevention of CVD improved triglyceride and high-density lipoprotein-cholesterol concentrations but did not improve cardiovascular outcomes or kidney function, and was associated with higher all-cause mortality.

Subcutaneous implantable cardioverter defibrillator for dialysis patients: a strategy to reduce central vein stenoses and infections.

Central venous stenosis is a common complication of the transvenous leads associated with an implantable cardioverter defibrillator (ICD). Although epicardial leads have been reported to bypass this complication, their placement is much more invasive than the subcutaneous ICDs (SICDs) and requires the services of a cardiothoracic surgeon. Recent data have demonstrated successful defibrillation using an SICD. In this report, we present 4 long-term hemodialysis patients treated successfully with an SICD. 3 patients received the device for primary prevention of sudden cardiac death (cardiomyopathy with low ejection fraction). The patient in the fourth case had a prolonged QT interval and received the device for secondary prevention. 3 patients had an arteriovenous fistula, whereas 1 patient was dialyzing with a tunneled dialysis catheter. Insertion of an SICD is a minimally invasive procedure. By virtue of leaving the venous system untouched, this approach might offer the advantage of reduced risk of central venous stenosis and infection over an endocardial ICD with transvenous leads. SICD is not experimental; it has been approved by the US Food and Drug Administration and is currently being used in the United States and Europe.

The impact of arteriovenous fistulae on the myocardium: the impact of creation and ligation in the transplant era.

Cardiac hypertrophy is a relatively common complication seen in patients with advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD). Moreover, cardiac hypertrophy is even more frequently seen in patients with ESRD who have an arteriovenous (AV) access. There has been substantial evidence pertaining to the effects of AV access creation on the heart structure and function. Similarly, there is increasing evidence on the effects of AV access closure, flow reduction, transplantation, and immunosuppressive medication on both endpoints. In this review, we present the evidence available in the literature on these topics and open the dialog for further research in this interesting field.

A meta-analysis of randomized clinical trials assessing hemodialysis access thrombosis based on access flow monitoring: where do we stand?

The National Kidney Foundation Kidney Disease Outcomes Quality Initiative recommends the routine use of hemodialysis arteriovenous (AV) access surveillance to detect hemodynamically significant stenoses and appropriately correct them to reduce the incidence of thrombosis and to improve accesses patency rates. Access blood flow monitoring is considered as one of the preferred surveillance method for both AV fistulas (AVF) and AV grafts (AVG); however, published studies have reported conflicting results of its utility that led healthcare professionals to doubt the benefits of this surveillance method. We performed a meta-analysis of the published randomized controlled trials (RCTs) of AV access surveillance using access blood flow monitoring. Our hypothesis was that access blood flow monitoring lowers the risk of AV access thrombosis and that the outcome differs between AVF and AVG. The estimated overall pooled risk ratio (RR) of thrombosis was 0.87 (95% confidence interval [CI], 0.67-1.13) favoring access blood flow monitoring. The pooled RR of thrombosis were 0.64 (95% CI, 0.41-1.01) and 1.06 (95% CI, 0.77-1.46) in the subgroups of only AVF and only AVG, respectively. Our results added to the uncertainty of access blood flow monitoring as a surveillance method of hemodialysis accesses.