Occlusive cutaneous vasculopathies as cause of chronic ulcers

The term occluding vasculopathies covers a large number of different conditions. These often manifest as skin ulcers. Occluding vasculopathies should be considered in the differential diagnosis of leg ulcers. The term "occlusive vasculopathies" encompasses pathophysiologically related entities that share structural or thrombotic obliteration of small cutaneous vessels. In this article, we will focus on livedoid vasculopathy with and without antiphospholipid syndrome and calciphylaxis with differentiation from hypertonic leg ulcer as the most relevant differential diagnoses of leg ulcer. The term also includes vascular occlusion, for example due to oxalate or cholesterol embolism, and septic vasculopathy. This often leads to acral ulceration and is therefore not a differential diagnosis with classic leg ulcers. It will not be discussed in this article. Occlusive vasculopathy may be suspected in the presence of the typical livedo racemosa or (non-inflammatory) retiform purpura as a sign of reduced cutaneous perfusion in the wound area. Inflammatory dermatoses, especially vasculitides, must be differentiated. This is achieved by histopathological evaluation of a tissue sample of sufficient size and depth taken at the appropriate time. In addition, specific laboratory parameters, particularly coagulation parameters, can support the diagnosis.

Okkludierende kutane Vaskulopathien als Ursachen chronischer Unterschenkelulzerationen

Unter den Begriff der okkludierenden Vaskulopathien fällt eine Reihe unterschiedlicher Krankheitsbilder. Diese manifestieren sich an der Haut häufig mit Ulzerationen. Gerade bei Ulzerationen der Unterschenkel sollten okkludierende Vaskulopathien in die differenzialdiagnostischen Überlegungen einbezogen werden. Der Begriff „okkludierende Vaskulopathien“ umfasst pathophysiologisch verwandte Entitäten, die eine strukturelle oder thrombotische Obliteration von kleinsten Hautgefäßen gemein haben. In diesem Artikel wird vor allem auf die Livedovaskulopathie mit und ohne Antiphospholipidsyndrom sowie die Calciphylaxie mit Abgrenzung zum Ulcus cruris hypertonicum als die relevantesten Differenzialdiagnosen von Unterschenkelulzerationen eingegangen. Der Begriff umfasst auch Gefäßverschlüsse, beispielsweise durch Oxalat oder Cholesterinembolie, sowie die septische Vaskulopathie. Diese führt häufig zu akralen Ulzerationen und stellt somit keine Differenzialdiagnose zum klassischen Ulcus cruris dar. Sie wird daher in diesem Artikel nicht behandelt.

Der Verdacht einer okkludierenden Vaskulopathie kann über die typische Livedo racemosa beziehungsweise die (nichtinflammatorische) retiforme Purpura als Zeichen der kutanen Minderdurchblutung in der Wundumgebung gestellt werden. Entzündliche Dermatosen, insbesondere Vaskulitiden, müssen differenzialdiagnostisch abgegrenzt werden. Dies geschieht zum Teil klinisch und durch die histopathologische Beurteilung einer Gewebeprobe, die in ausreichender Größe und Tiefe sowie zum richtigen Zeitpunkt entnommen werden muss. Ergänzend können spezifische Laborparameter, insbesondere die Gerinnungsdiagnostik, die Diagnosestellung unterstützen.

Successful Treatment Using Apixaban in a Patient on Hemodialysis with Uremic Calciphylaxis

Calciphylaxis is a rare but serious condition in which microvessel occlusion occurs within the subcutaneous adipose tissue and dermis, leading to painful lesions. End-stage renal disease requiring hemodialysis and warfarin therapy can increase the risk of calciphylaxis. In this report, we describe the evaluation and treatment of a 75-year-old female patient with warfarin-induced calciphylaxis who presented unique symptoms. The patient required intensive care unit admission due to hemodynamic instability, which was treated with inotropes and broad-spectrum intravenous antibiotics. This description of the patient's unusual symptoms has the potential to provide insights needed to improve the diagnosis of future patients. Due to the unavailability of FDA-approved treatment for calciphylaxis, its management is based on data from observational studies and clinical experience.

Altered vitamin K biodistribution and metabolism in experimental and human chronic kidney disease

Chronic kidney disease (CKD) is accompanied with extensive cardiovascular calcification, in part correlating with functional vitamin K deficiency. Here, we sought to determine causes for vitamin K deficiency beyond reduced dietary intake. Initially, vitamin K uptake and distribution into circulating lipoproteins after a single administration of vitamin K1 plus K2 (menaquinone 4 and menaquinone 7, respectively) was determined in patients on dialysis therapy and healthy individuals. The patients incorporated very little menaquinone 7 but more menaquinone 4 into high density lipoprotein (HDL) and low-density lipoprotein particles than did healthy individuals. In contrast to healthy persons, HDL particles from the patients could not be spiked with menaquinone 7 in vitro and HDL uptake was diminished in osteoblasts. A reduced carboxylation activity (low vitamin K activity) of uremic HDL particles spiked with menaquinone 7 vs. that of controls was confirmed in a bioassay using human primary vascular smooth muscle cells. Kidney menaquinone 4 tissue levels were reduced in 5/6-nephrectomized versus sham-operated C57BL/6 mice after four weeks of a vitamin K rich diet. From the analyzed enzymes involved in vitamin K metabolism, kidney HMG-CoA reductase protein was reduced in both rats and patients with CKD. In a trial on the efficacy and safety of atorvastatin in 1051 patients with type 2 diabetes receiving dialysis therapy, no pronounced vitamin K deficiency was noted. However, the highest levels of PIVKA-II (biomarker of subclinical vitamin K deficiency) were noted when a statin was combined with a proton pump inhibitor. Thus, profound disturbances in lipoprotein mediated vitamin K transport and metabolism in uremia suggest that menaquinone 7 supplementation to patients on dialysis therapy has reduced efficacy.

Benefit and harm of anticoagulation in the prevention of thromboembolic stroke for non- valvular atrial fibrillation in haemodialysis patients - a Top End of Northern Australia study

BACKGROUND

Warfarin for the prevention of non-valvular atrial fibrillation related thromboembolic stroke in patients on maintenance haemodialysis is controversial. Despite the exclusion of haemodialysis patients in randomised control trials, the American Heart Association/American College of Cardiology has recommended warfarin in high-risk AF patients.

AIM

We retrospectively examined the utility of warfarin anticoagulation therapy in our prevalent haemodialysis patients over 10 years of follow-up.

METHODS

Eligible patients were retrospectively identified and stratified to two cohorts based on whether warfarin was prescribed. The outcomes of interest were ischaemic stroke, haemorrhagic stroke and death from any cause. Rate ratio and cox proportional hazard regression model were compare the differences in outcome between the two cohorts. The Kaplan-Meier method was used to analyse survival.

RESULTS

Three ischaemic strokes and four haemorrhagic strokes occurred in the unexposed group of 166 patients over 484.44 patient-years follow-up. One ischaemic stroke and no cases of haemorrhagic stroke occurred in the exposed warfarin group of 16 patients over 39.32 patient-years of follow-up. 87% of patients in both groups were indigenous. More than 90% of each cohort was had CHA2DS2VaSc score ≥2. 101 deaths occurred in the follow-up period, ninety in the unexposed group and eleven in the warfarin group. A non-statistically significant trend towards increasing mortality was observed in the warfarin group (Hazard ratio =1.63, p=0.13).

CONCLUSION

This retrospective study of prevalent haemodialysis patients with co-existing history of non-valvular AF failed to demonstrate sufficient evidence for the routine use of warfarin for prophylaxis of thromboembolic stroke. This article is protected by copyright. All rights reserved.

[Features of anticoagulant therapy of atrial fibrillation in combination with impaired renal function]

This review focuses on issues of anticoagulant therapy in patients with atrial fibrillation (AF) associated with chronic kidney disease (CKD). Such patients are at high risk of stroke whereas the choice of an anticoagulant is difficult. A wealth of information about a negative effect of warfarin on the kidney function has accumulated. A need for an alternative therapy to warfarin for patients with stage 3-4 CKD has become imminent. In this regard, rivaroxaban seems to be an appropriate replacement for warfarin in such patients. In randomized, controlled studies that evaluated the efficacy of direct oral anticoagulants in comparison with warfarin, the efficacy and safety profile of a "kidney" dose in moderate disorders of kidney function has been studied only for rivaroxaban. Moreover, both randomized, controlled studies and studies performed in the conditions of clinical practice, have demonstrated a more favorable effect of rivaroxaban on kidney function compared to warfarin. Patients with AF associated with CKD require a comprehensive protection, which, according to results of clinical studies, may be provided by rivaroxaban.

Atrial fibrillation in advanced renal failure: are there alternative solutions to warfarin-dicumarol?

Patients with atrial fibrillation (AF) and chronic renal failure (CRF) represent a growing population in epidemiological terms since both conditions increase with advancing age. The association of AF and CRF is burdened with a poor prognosis and with a high risk of adverse events, both ischaemic and haemorrhagic. Oral anticoagulant therapy, in these patients, is more problematic, especially due to the concomitant increased risk of bleeding. The use of direct oral anticoagulants (DOACs) in patients with non-severe renal insufficiency appears to be safe and effective. Since all currently available DOACs are at least partially eliminated by the kidney (dabigatran is the direct anticoagulant with the highest rate of renal elimination, approximately 80%), periodic monitoring of renal function is recommended to evaluate possible need for dosage adjustment. In patients with advanced renal insufficiency, the use of DOAC appears controversial, given the small number of clinical studies that have tested its efficacy and safety. It is known, however, that oral anticoagulation therapy with vitamin K antagonists (VKAs) is associated with an increase in nephropathy and renal-vascular calcification. From this point of view, therapy with DOAC could be more advantageous than VKAs. Data from clinical studies would seem to show that the use of dabigatran and rivaroxaban in these patients may lead to a reduction in the inevitable deterioration of renal function.

Nonatherosclerotic Vascular Abnormalities Associated with Chronic Kidney Disease

Nonatherosclerotic vascular diseases are manifested by endothelial dysfunction, hypertension, vascular calcification, coronary microvascular dysfunction, and calciphylaxis. Unfortunately, there are no definitive treatments for many of these disorders other than hypertension. In addition, although hypertension is more difficult to treat in the chronic kidney disease population, it is necessary to try and target a blood pressure of less than 130/80 mm Hg through the use of aggressive angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, diuretics, and other antihypertensive medications. New therapies are being actively investigated in an attempt to treat nonatherosclerotic vascular diseases in the chronic kidney disease population.

Calciphylaxis: Risk Factors and Histologic Findings in a Case Series From a Tertiary Care Referral Hospital

Recent years have seen important advances in our understanding of calciphylaxis, especially regarding newly identified risk factors and histologic findings that may aid diagnosis. This retrospective study of cases of calciphylaxis treated in our hospital in the last 13 years focuses on newly revealed aspects of this disease. We describe 16 patients (62.5% women; mean age, 67.9 years). In addition to advanced kidney disease (in 75% of our patients), other factors associated with the presence of calciphylaxis were a history of treatments related to phosphorus and calcium metabolism (75%) and anticoagulation (62.5%), usually with vitamin-K antagonists. Histology showed alterations in elastic fibers in only 25% of the biopsy specimens. Eleven of the patients died: sepsis was most often the cause.

Calcific Uremic Arteriolopathy: A Case Series and Review from an Inner-City Tertiary University Center in End-Stage Renal Disease Patients on Renal Replacement Therapy

Materials and Methods

24 patients with CUA and on RRT were evaluated at Detroit Medical Center from 2007 to 2016. Skin biopsy was used in almost all patients, along with the radiological and clinical findings. The patient's clinical and paraclinical data were retrieved from the electronic medical records. The effect of treatment modalities and the underlying hyperparathyroidism management were compared to the clinical outcomes using appropriate statistical tests.

Results

Twenty-one patients were on hemodialysis, two patients received renal transplants, and one patient was on peritoneal dialysis. Diabetes mellitus was the most prevalent cause of ESRD. The parathyroid hormone level (PTH) was elevated in 22 patients. Fifteen patients were diagnosed 2 weeks or more prior to skin lesion onset. Twenty-two and thirteen patients received sodium thiosulphate and cinacalcet, respectively. Patients with lower PTH and the calcium-phosphate product levels had a relatively better outcome of CUA.

Conclusions

A multifaceted approach may play a role in treating CUA. Referral to a nephrologist may aid in the early diagnosis and prompt management of CUA.

Pain management in patients with end-stage renal disease and calciphylaxis- a survey of clinical practices among physicians

BACKGROUND

Calciphylaxis is a rare condition usually seen in patients with end-stage renal disease. Pain is a hallmark of this condition and can be extremely difficult to control. Anecdotal data suggests that pain management in calciphylaxis is challenging with variable approaches across the United Kingdom (UK) and internationally. A knowledge and practice survey was conducted to establish current practice in the management of pain in patients with calciphylaxis, in the UK. Based on the results and clinical experience the authors suggest a clinical practice guideline.

METHODS

An online questionnaire was circulated among physicians (renal and palliative care) involved in the management of pain in calciphylaxis. The questionnaire included a mix of open-ended questions and questions with drop down options.

RESULTS

One hundred and six clinicians responded to the survey of which 60 (57%) respondents were from palliative medicine; the remaining 46 (43%) were from renal medicine. 31 (30%) respondents across both specialties had not encountered any patients with a diagnosis of calciphylaxis (renal-2, palliative care-29). A referral to the palliative care team was undertaken by 18% of renal physicians, 32% referred to the pain team and 50% referred to both. Only 3% of the palliative medicine respondents indicated that they had received a referral from the renal team at the time of diagnosis. Opioids were the preferred initial drug of choice for the management of all types of pain. Paracetamol was universally selected as the preferred first-choice adjuvant agent for management of all types of pain. The importance of advance care planning was highlighted with 72% undertaking advanced care planning discussions often or most of the time.

CONCLUSION

There was wide variation in the current practice of pain management in patients with calciphylaxis, with variation between renal specialists and palliative care specialists. Referral to specialists in pain management is not universal despite the severe nature of the pain experienced by patients with calciphylaxis. The data generated has facilitated the development of a clinical practice guideline to support complex pain management in a group of patients with multiple comorbidities.

Calciphylaxis: An Analysis of Concomitant Factors, Treatment Effectiveness and Prognosis in 30 Patients

Background

Calciphylaxis is a rare but severe complication mostly affecting patients with end-stage renal disease (ESRD) and is associated with high morbidity and mortality. The natural history, concomitant factors, pathogenesis, and treatment for calciphylaxis remain equivocal.

Methods

We conducted a retrospective study on patients diagnosed with calciphylaxis in a tertiary care center between January 1, 2012, and December 31, 2017. We describe demographics, co-morbidities, laboratory parameters, effectiveness of sodium thiosulfate treatment and outcomes.

Results

Of the 30 patients (age 65.6 ± 12.79 years, male:female = 8:22), 23 (76.67%) had ESRD and were either on hemodialysis (15 [65.22%], median duration 22.5 months [range 0.2–96 months]) or peritoneal dialysis (8 [34.78%], duration 29±10 months). Predisposing home medications: 8 (28%) had calcium supplements, 10 (36%) had warfarin, 16 (57%) had vitamin D and 5 (18%) had iron supplements. The median parathyroid hormone (PTH) level was 239.8 pg/mL (range 4.7–2922). Calciphylaxis was found on extremities in 21 (70%) and on torso in 6 (20%) patients. Sodium thiosulfate (STS) was given for treatment in 20 (67%) patients and 3 were cured in <2.25 months. One-year survival for all patients with calciphylaxis was 26% (29% for STS group and 20% for those that did not receive STS) and following any surgical treatment regardless of STS use was 14%.

Limitations

Retrospective design, absence of a control group and low power.

Conclusion

Calciphylaxis was more common among females with a predilection for extremities over the torso. Elevations in PTH and inflammatory markers were common. Treatment with STS did not show a statistically significant improvement in survival. Those who were cured, were treated with STS up to three months.

[Atrial Fibrillation in Patients on Dialysis Therapy: Epidemiology, Prognosis and Choice of Anticoagulant Therapy]

The review presents data on the prevalence of atrial fibrillation in patients on dialysis therapy. It is shown that dialysis-dependent patients with non-valve atrial fibrillation prognosis is extremely unfavorable, significantly increased risk of death due to both ischemic and hemorrhagic complications. Scales to assess the risk of thromboembolic and hemorrhagic complications in patients with atrial fibrillation on program dialysis are not validated. The lack of data from randomized clinical trials makes it much more difficult to choose anticoagulant therapy in patients with terminal stage of chronic kidney disease on dialysis who have undergone kidney transplantation. Therefore, the need for anticoagulant therapy and the choice of drugs in patients in this category should be made on the basis of a personalized multidisciplinary approach, taking into account comorbid pathology and the patient's preferences.

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

Anticoagulation in Patients With Advanced Chronic Kidney Disease: Walking the Fine Line Between Benefit and Harm

Chronic kidney disease affects more than 3 million Canadians and is highly associated with cardiovascular diseases that require anticoagulation, such as atrial fibrillation and venous thromboembolism. Patients with chronic kidney disease are at a problematic crossroads; they are at high risk of thrombotic conditions requiring anticoagulation and bleeding complications due to anticoagulation. The limited high-quality clinical evidence to guide decision-making in this area further compounds the dilemma. In this review, we discuss the physiology and epidemiology of bleeding and thrombosis in patients with kidney disease. We specifically focus on patients with advanced kidney disease (estimated glomerular filtration rate ≤ 30 mL/min) or who are receiving dialysis and focus on the nephrologist perspective regarding these issues. We summarize the existing evidence for anticoagulation use in the prevention of stroke with atrial fibrillation and provide practical clinical recommendations for considering anticoagulation use in this population. Last, we examine specific scenarios such as the use of a glomerular filtration rate estimating equation and dosing, the use of existing prediction tools for stroke and hemorrhage risk, current patterns of anticoagulation use (including during the dialysis procedure), and vascular calcification with vitamin K antagonist use in patients with chronic kidney disease.

Oral Anticoagulants in Patients With Atrial Fibrillation and End-Stage Renal Disease

The role of oral anticoagulants (OAC) in atrial fibrillation (AF) is well established. However, none of the randomized controlled trials included patients with end-stage renal disease (ESRD) leaving a lack of evidence in this large, challenging and unique patient group. Patients on hemodialysis (HD) with AF have additional risk factors for stroke due to vascular comorbidities, HD treatment, age, and diabetes. Conversely, they are also at increased risk of major bleeding due to uremic platelet impairment. Anticoagulants increase bleeding risk in patients with ESRD and HD up to 10-fold compared with non chronic kidney disease (CKD) patients on warfarin. There are conflicting data and recommendations regarding use of OACs in ESRD which will be reviewed in this article. We conclude by proposing a modified strategy for OAC use in ESRD based on the latest evidence.

Calcific uremic arteriolopathy (calciphylaxis) calls into question the validity of guidelines of diagnosis and treatment

Background: Calciphylaxis is associated with end-stage renal failure or kidney transplant, although, cases of non-uremic calciphylaxis have been reported. It is a rare disorder, with high mortality, characterized by vascular calcification within cutaneous vessels; vascular calcification can occur in other organs, besides skin, like heart, lung, or pancreas, which is named visceral calciphylaxis.Objective: The purpose was to review current knowledge regarding diagnosis and therapeutic approach to cutaneous calciphylaxis.Methods: A literature review has been conducted associated to word "calciphylaxis".Results: The diagnosis is based mainly on clinical features and histologic findings. Therapeutic options are still controversial.Conclusions: Cutaneous calciphylaxis is a puzzling disease, with a challenging diagnosis, and a complex treatment, which requires a multidisciplinary team and expertise.

Systematic review of sodium thiosulfate in treating calciphylaxis in chronic kidney disease patients

AIM

Calciphylaxis is a severe complication of advanced chronic kidney disease (CKD). Sodium thiosulphate (STS), an antioxidant and calcium chelating agent, has been used for the treatment of calciphylaxis. However, its efficacy and safety have not been systematically analysed and evaluated.

METHODS

MEDLINE, EMBASE, and the Cochrane Library database were systematically searched for case report or cases series on use of STS for calciphylaxis published between July 1974 and October 2016. We extracted data on clinical characteristics, laboratory tests result and medication use. The effective treatment was defined as improvement in skin lesion cicatrisation or pain relief without death. Non-responding effects were defined as stable skin lesions without remission or exacerbation of the disease in patients who remained alive. All-cause mortality after STS treatment was defined as death due to exacerbations of calciphylaxis or other complications of advanced CKD. We compared the baseline parameters of the patients as well as the efficacy and mortality of the STS therapy between case report and multi-case reports. Statistical analyses were performed using SPSS 19.

RESULTS

A total of 83 papers were screened, 45 of them (n = 358) met the inclusion criteria, including 36 case reports (n = 64) and nine multi-case reports (n = 294). The mean age of the patients with calciphylaxis was 58 ± 14 years (range 26-91 years). They were female predominant, accounting for 74.1%. Among the patients with calciphylaxis, 96.1% patients were on dialysis with median dialysis vintage of 44.5 months (range 24-84 months). STS was effective in 70.1% of patients, 37.6% patients died. The proportion of patients with sepsis was higher among those who received intravenous STS. There was no significant difference in efficacy between the different STS administration methods (P = 0.19).

CONCLUSION

Although the study was unable to assess the efficacy of sodium thiosulphate alone in the treatment of calciphylaxis, it still reveals a promising role of STS as an effective therapy for calciphylaxis. Further prospective studies to define the optimal therapy for calciphylaxis are needed.

[Calcific uremic arteriolopathy in hemodialysis patient, review of literature through five cases reports]

Calcific uremic arteriolopathy, also called calciphylaxis, is a rare and severe disorder that presents with skin ischemia and necrosis, sometimes it presents with systemic necrosis, the process is secondary to the obliteration of the arterioles first by sub-intimal calcium deposits and then by thrombosis. These lesions can often lead to death due to infectious complications and comorbidities such as diabetes, obesity, arteritis, diffuse vascular calcifications, heart disease and undernutrition. The diagnosis is suggested by the characteristic ischemic skin lesions and their distribution, often bilateral and painful, associeted with calcific uremic arteriolopathy risk factors (phosphocalcic abnormalities, anti-vitamin K). The presence of radiological vascular calcifications is highly suggesting the diagnosis, but remains not very specific. The indication of skin biopsy is rare and reserved for difficult diagnoses. The goals of treatment are: reduce the extension of calcification and treatment of mineral and bone metabolism disorders of end-stage renal disease, dialysis adequacy, local treatment of skin lesions, tissue oxygenation, pain management, discontinuation and contraindication of medications that may contribute to the disorder. We propose to discuss it from a review of the literature and illustrate it with five clinical cases.

Use of oral anticoagulants in patients with atrial fibrillation and renal dysfunction

Atrial fibrillation (AF) and chronic kidney disease (CKD) are increasingly prevalent in the general population and share common risk factors such as older age, hypertension and diabetes mellitus. The presence of CKD increases the risk of incident AF, and, likewise, AF increases the risk of CKD development and/or progression. Both conditions are associated with substantial thromboembolic risk, but patients with advanced CKD also exhibit a paradoxical increase in bleeding risk. In the landmark randomized clinical trials that compared non-vitamin K antagonist oral anticoagulants (NOACs) with warfarin for thromboprophylaxis in patients with AF, the efficacy and safety of NOACs in patients with mild-to-moderate CKD were similar to those in patients without CKD. Dose adjustment of NOACs as per the prescribing label is required in this population. Owing to limited trial data, evidence-based recommendations for the management of patients with AF and severe CKD or end-stage renal disease on dialysis are lacking. Observational cohort studies have reported conflicting results, and the management of these particularly vulnerable patients remains challenging and requires careful assessment of stroke and bleeding risk and, where appropriate, use of warfarin with good-quality anticoagulation control.

Effects of warfarin on biological processes other than haemostasis: A review

Warfarin is the world's most widely used anticoagulant drug. Its anticoagulant activity is based on the inhibition of the vitamin K-dependent (VKD) step in the complete synthesis of a number of blood coagulation factors that are required for normal blood coagulation. Warfarin also affects synthesis of VKD proteins not related to haemostasis including those involved in bone growth and vascular calcification. Antithrombotic activity of warfarin is considered responsible for some aspects of its anti-tumour activity of warfarin. Some aspects of activities against tumours seem not to be related to haemostasis and included effects of warfarin on non-haemostatic VKD proteins as well as those not related to VKD proteins. Inflammatory/immunomodulatory effects of warfarin indicate much broader potential of action of this drug both in physiological and pathological processes. This review provides an overview of the published data dealing with the effects of warfarin on biological processes other than haemostasis.

Anticoagulation for Stroke Prevention in Older Adults with Atrial Fibrillation and Comorbidity: Current Evidence and Treatment Challenges

The burden of atrial fibrillation (AF) is projected to increase substantially over the next decade in parallel with the aging of the population. The increasing age, level of comorbidity, and polypharmacy will complicate the treatment of older adults with AF. For instance, advanced age and chronic kidney disease have been shown to increase the risk of both thromboembolism and bleeding in patients with AF. Frailty, recurrent falls and polypharmacy, while very common among elderly patients with AF, are often overlooked in the clinical decision making despite their significant interaction with oral anticoagulant (OAC) and profound impact on the patient's clinical outcomes. Such factors should be recognized, evaluated and considered in a comprehensive decision-making process. The introduction of non-vitamin K oral anticoagulants has radically changed the management of AF allowing for a more individualized selection of OAC. An understanding of the available data regarding the performance of each of the available OAC in a variety of at risk patient populations is paramount for the safe and effective management of this patient population. The aim of this review is to appraise the current evidence, point out the gaps in knowledge, and provide recommendations regarding stroke prevention in older adults with AF and comorbid conditions.

3DTEE imaging of a descending aorta floating thrombus in a patient with calciphylaxis

We present a case of a 68-year-old man with calciphylaxis, who was found to have a floating thrombus in the descending aorta on a transesophageal echocardiogram. The use of 3D echocardiography demonstrated nicely the free motion of the thrombus, emerging from an atherosclerotic plaque in the descending aorta. Anticoagulation was started for thromboembolism prevention.

The Synergistic Interplay between Vitamins D and K for Bone and Cardiovascular Health: A Narrative Review

Vitamins D and K are both fat-soluble vitamins and play a central role in calcium metabolism. Vitamin D promotes the production of vitamin K-dependent proteins, which require vitamin K for carboxylation in order to function properly. The purpose of this review is to summarize available evidence of the synergistic interplay between vitamins D and K on bone and cardiovascular health. Animal and human studies suggest that optimal concentrations of both vitamin D and vitamin K are beneficial for bone and cardiovascular health as supported by genetic, molecular, cellular, and human studies. Most clinical trials studied vitamin D and K supplementation with bone health in postmenopausal women. Few intervention trials studied vitamin D and K supplementation with cardiovascular-related outcomes. These limited studies indicate that joint supplementation might be beneficial for cardiovascular health. Current evidence supports the notion that joint supplementation of vitamins D and K might be more effective than the consumption of either alone for bone and cardiovascular health. As more is discovered about the powerful combination of vitamins D and K, it gives a renewed reason to eat a healthy diet including a variety of foods such as vegetables and fermented dairy for bone and cardiovascular health.

Consequences of Venous Thromboembolism, Including Chronic Thromboembolic Pulmonary Hypertension

Venous thromboembolism includes both deep vein thrombosis and pulmonary embolism. They pose a significant risk for morbidity and mortality. In an appropriate clinical setting, invasive interventions, including administration of thrombolytics, anticoagulation, and placement of vena cava filter, are warranted. Bleeding, postthrombotic syndrome, recurrence, and filter-associated complications are few of the complications of this disease. More recently, chronic thromboembolic pulmonary hypertension has gained clinical interest in patients with pulmonary embolism and has warranted close follow-up.

The Strategy to Prevent and Regress the Vascular Calcification in Dialysis Patients

The high prevalence of arterial calcification in end-stage renal disease (ESRD) is far beyond the explanation by common cardiovascular risk factors such as aging, diabetes, hypertension, and dyslipidemia. The finding relies on the fact that vascular and valvular calcifications are predictors of cardiovascular diseases and mortality in persons with chronic renal failure. In addition to traditional cardiovascular risk factors such as diabetes mellitus and blood pressure control, other ESRD-related risks such as phosphate retention, excess calcium, and prolonged dialysis time also contribute to the development of vascular calcification. The strategies are to reverse "calcium paradox" and lower vascular calcification by decreasing procalcific factors including minimization of inflammation (through adequate dialysis and by avoiding malnutrition, intravenous labile iron, and positive calcium and phosphate balance), correction of high and low bone turnover, and restoration of anticalcification factor balance such as correction of vitamin D and K deficiency; parathyroid intervention is reserved for severe hyperparathyroidism. The role of bone antiresorption therapy such as bisphosphonates and denosumab in vascular calcification in high-bone-turnover disease remains unclear. The limited data on sodium thiosulfate are promising. However, if calcification is to be targeted, ensure that bone health is not compromised by the treatments.

A Nationally Representative Study of Calcific Uremic Arteriolopathy Risk Factors

Accurate identification of risk factors for calcific uremic arteriolopathy (CUA) is necessary to develop preventive strategies for this morbid disease. We investigated whether baseline factors recorded at hemodialysis initiation would identify patients at risk for future CUA in a matched case-control study using data from a large dialysis organization. Hemodialysis patients with newly diagnosed CUA (n=1030) between January 1, 2010, and December 31, 2014, were matched by age, sex, and race in a 1:2 ratio to hemodialysis patients without CUA (n=2060). Mean ages for patients and controls were 54 and 55 years, respectively; 67% of participants were women and 49% were white. Median duration between hemodialysis initiation and subsequent CUA development was 925 days (interquartile range, 273-2185 days). In multivariable conditional logistic regression analyses, diabetes mellitus; higher body mass index; higher levels of serum calcium, phosphorous, and parathyroid hormone; and nutritional vitamin D, cinacalcet, and warfarin treatments were associated with increased odds of subsequent CUA development. Compared with patients with diabetes receiving no insulin injections, those receiving insulin injections had a dose-response increase in the odds of CUA involving lower abdomen and/or upper thigh areas (odds ratio, 1.49; 95% confidence interval, 1.03 to 2.51 for one or two injections per day; odds ratio, 1.88; 95% confidence interval, 1.30 to 3.43 for 3 injections per day; odds ratio, 3.74; 95% confidence interval, 2.28 to 6.25 for more than three injections per day), suggesting a dose-effect relationship between recurrent skin trauma and CUA risk. The presence of risk factors months to years before CUA development observed in this study will direct the design of preventive strategies and inform CUA pathobiology.

Calciphylaxis in peritoneal dialysis patients: a single center cohort study

BACKGROUND

Calciphylaxis is a rare but devastating condition in end-stage renal disease (ESRD) patients. Most research in the field of calciphylaxis is focused on hemodialysis (HD) patients; however, data on calciphylaxis incidence, risk factors, and mortality in peritoneal dialysis (PD) patients are limited.

METHODS

In this cohort study, we examined data from adult patients who initiated PD for ESRD management at our institute's PD unit from January 2001 to December 2015. Associations with the development of calciphylaxis were examined for clinical, laboratory, and medication exposures. Incidence of calciphylaxis and mortality in PD patients who developed calciphylaxis were analyzed. Treatments administered to treat calciphylaxis in PD patients were summarized.

RESULTS

In this cohort of 63 patients, 7 patients developed calciphylaxis (incidence rate: 9.0 per 1,000 patient-years). Median age of PD patients who developed calciphylaxis was 50 years, 57% were white, 71% females, and 71% were previously on HD. Female sex, obesity, HD as a prior dialysis modality, recurrent hypotension, elevated time-averaged serum phosphorous levels, reduced time-averaged serum albumin levels, and warfarin therapy were associated with increased calciphylaxis risk in univariate logistic regression analyses. Intravenous sodium thiosulfate was administered in 57% of PD patients who developed calciphylaxis. One-year mortality in PD patients who developed calciphylaxis was 71% despite multimodal treatment including sodium thiosulfate, hyperbaric oxygen, cinacalcet, and wound debridement.

CONCLUSION

Calciphylaxis is a rare but frequently fatal condition in PD patients. Our study provides critical early insights into calciphylaxis incidence, risk factors, and prognosis in PD patients. Sample size and characteristics of patients included in our study limit generalizability to overall PD population and warrant examination in larger independent studies.

Multidisciplinary approach to calcific uremic arteriolopathy

PURPOSE OF REVIEW

Calcific uremic arteriolopathy (CUA), as known as calciphylaxis, is a rare and poorly understood disease seen predominantly in end stage renal disease patients. A collaborative multidisciplinary approach to develop and implement treatment and prevention methods is described.

RECENT FINDINGS

Overall, the scientific literature on CUA is largely restricted to case reports and case series. Recent reports indicate that the incidence of CUA may be on the rise and emphasize an association with vitamin K antagonist therapy, obesity, and diabetes mellitus. Serum calcium, phosphorous, and parathyroid hormone levels have been reported to be quite variable in patients with CUA and may reflect the heterogeneity of study designs. A multidisciplinary and multimodal approach that incorporates wound and pain management, sodium thiosulfate, optimization of mineral bone parameters, bisphosphonates, and avoidance of risk factors such as vitamin K antagonist has been advocated in the latest reports. Sodium thiosulfate although used frequently to treat CUA has unclear efficacy requiring further examination.

SUMMARY

This review describes the recent literature in the field of CUA including its limitations. It provides a summary of a multidisciplinary approach to CUA management.

Meta-Analysis of Anticoagulation Use, Stroke, Thromboembolism, Bleeding, and Mortality in Patients With Atrial Fibrillation on Dialysis

Atrial fibrillation (AF) is common in patients on dialysis. Although randomized trials of anticoagulation for AF have demonstrated striking reductions in stroke, these trials did not recruit patients on dialysis. We thus undertook this systematic review and meta-analysis of observational studies including patients with AF on dialysis that reported associations of anticoagulation use. Twenty studies involving 529,741 subjects and 31,321 patients with AF on dialysis were identified. Anticoagulation was associated with a 45% (95% CI 13% to 88%) increased risk of any stroke, reflecting a nonsignificant 13% (95% CI -4% to 34%) increased ischemic stroke risk and 38% (95% CI 3% to 85%) increased hemorrhagic stroke risk. There was also a 44% (95% CI 38% to 56%) lower risk of any thromboembolism, and a 31% (95% CI 12% to 53%) increased risk of any bleeding but no clear association with cardiovascular death (relative risk 0.99, 95% CI 0.86 to 1.15) or all-cause mortality (relative risk 0.97, 95% CI 0.90 to 1.04). Incident event rates were similar or worse in patients on anticoagulation. In conclusion, these observational analyses provide little supporting evidence of benefit, and instead suggest harm, from anticoagulation in patients on dialysis with AF. These results raise the possibility that the effects of anticoagulation in patients with AF on dialysis may not be similar to the clear benefit of anticoagulation seen in patients with AF without end-stage renal disease. Randomized trials are required to definitively evaluate the safety and efficacy of anticoagulation for AF in the dialysis setting.

Surgical management of secondary hyperparathyroidism in chronic kidney disease--a consensus report of the European Society of Endocrine Surgeons

BACKGROUND

Despite advances in the medical management of secondary hyperparathyroidism due to chronic renal failure and dialysis (renal hyperparathyroidism), parathyroid surgery remains an important treatment option in the spectrum of the disease. Patients with severe and complicated renal hyperparathyroidism (HPT), refractory or intolerant to medical therapy and patients with specific requirements in prospect of or excluded from renal transplantation may require parathyroidectomy for renal hyperparathyroidism.

METHODS

Present standard and actual controversial issues regarding surgical treatment of patients with hyperparathyroidism due to chronic renal failure were identified, and pertinent literature was searched and reviewed. Whenever applicable, evaluation of the level of evidence concerning diagnosis and management of renal hyperparathyroidism according to standard criteria and recommendation grading were employed. Results were discussed at the 6th Workshop of the European Society of Endocrine Surgeons entitled Hyperparathyroidism due to multiple gland disease: An evidence-based perspective.

RESULTS

Presently, literature reveals scant data, especially, no prospective randomized studies to provide sufficient levels of evidence to substantiate recommendations for surgery in renal hyperparathyroidism. Appropriate surgical management of renal hyperparathyroidism involves standard bilateral exploration with bilateral cervical thymectomy and a spectrum of four standardized types of parathyroid resection that reveal comparable outcome results with regard to levels of evidence and recommendation. Specific patient requirements may favour one over the other procedure according to individualized demands.

CONCLUSIONS

Surgery for patients with renal hyperparathyroidism in the era of calcimimetics continues to play an important role in selected patients and achieves efficient control of hyperparathyroidism. The overall success rate and long-term control of renal hyperparathyroidism and optimal handling of postoperative metabolic effects also depend on the timely indication, individually suitable type of parathyroid resection and specialized endocrine surgery.