Mechanism of erythropoietin-induced hypertension

Understanding the role of red blood cells in venous thromboembolism: A comprehensive review

Traditionally, red blood cells (RBCs) have been perceived as passive entities within the fibrin network, without any significant role in the pathophysiology of venous thromboembolism (VTE). This review explores the involvement of RBCs in the VTE process, summarizing previous study findings and providing a comprehensive review of the latest theories. At first, it explores the influence of abnormal RBC counts (as seen in polycythemia vera and with erythropoietin use) and the exposure of RBCs to phosphatidylserine (Ptd-L-Ser) in the pathophysiology of VTE. The mechanisms of endothelial injury induced by RBCs and their adhesion to the endothelium under different disease models are then demonstrated. We explore the role of physical and chemical interactions between RBCs and platelets, as well as the interactions between RBCs and neutrophils - particularly the neutrophil extracellular traps (NETs) released by neutrophils - in the process of VTE. Additionally, we investigate the effect of RBCs on thrombin activation through two pathways, namely, the FXIIa-FXI-FIX pathway and the prekallikrein-dependent pathway. Lastly, we discuss the impact of RBCs on clot volume. In conclusion, we propose several potential methods aimed at unraveling the role of RBCs and their interaction with other components in the vascular system in the pathogenesis of VTE.

Hypertension in chronic kidney disease: What lies behind the scene

Hypertension is a frequent condition encountered during kidney disease development and a leading cause in its progression. Hallmark factors contributing to hypertension constitute a complexity of events that progress chronic kidney disease (CKD) into end-stage renal disease (ESRD). Multiple crosstalk mechanisms are involved in sustaining the inevitable high blood pressure (BP) state in CKD, and these play an important role in the pathogenesis of increased cardiovascular (CV) events associated with CKD. The present review discusses relevant contributory mechanisms underpinning the promotion of hypertension and their consequent eventuation to renal damage and CV disease. In particular, salt and volume expansion, sympathetic nervous system (SNS) hyperactivity, upregulated renin–angiotensin–aldosterone system (RAAS), oxidative stress, vascular remodeling, endothelial dysfunction, and a range of mediators and signaling molecules which are thought to play a role in this concert of events are emphasized. As the control of high BP via therapeutic interventions can represent the key strategy to not only reduce BP but also the CV burden in kidney disease, evidence for major strategic pathways that can alleviate the progression of hypertensive kidney disease are highlighted. This review provides a particular focus on the impact of RAAS antagonists, renal nerve denervation, baroreflex stimulation, and other modalities affecting BP in the context of CKD, to provide interesting perspectives on the management of hypertensive nephropathy and associated CV comorbidities.

A Comparison of Hemodialysis and Peritoneal Dialysis in Patients with Cardiovascular Disease

The high prevalence of cardiovascular disease is caused by the traditional cardiovascular risk factors common among end-stage renal disease patients, and nontraditional risk factors attributed to underlying kidney disease, including chronic inflammation, anemia, bone mineral disease, and the dialysis procedure itself. Individualization of the treatment of cardiovascular disease in end-stage renal disease that could impact the underlying mechanisms of the cardiovascular diseases is important to improve outcomes. This article reviews and compares hemodialysis and peritoneal dialysis in association with different cardiovascular diseases affecting dialysis patients, including hypertension, coronary artery disease, myocardial stunning, cardiac arrhythmias, heart failure, and the cardiorenal syndrome.

Etiology and management of hypertension in patients with cancer

The pathophysiology of hypertension and cancer are intertwined. Hypertension has been associated with an increased likelihood of developing certain cancers and with higher cancer-related mortality. Moreover, various anticancer therapies have been reported to cause new elevated blood pressure or worsening of previously well-controlled hypertension. Hypertension is a well-established risk factor for the development of cardiovascular disease, which is rapidly emerging as one of the leading causes of death and disability in patients with cancer. In this review, we discuss the relationship between hypertension and cancer and the role that hypertension plays in exacerbating the risk for anthracycline- and trastuzumab-induced cardiomyopathy. We then review the common cancer therapies that have been associated with the development of hypertension, including VEGF inhibitors, small molecule tyrosine kinase inhibitors, proteasome inhibitors, alkylating agents, glucocorticoids, and immunosuppressive agents. When available, we present strategies for blood pressure management for each drug class. Finally, we discuss blood pressure goals for patients with cancer and strategies for assessment and management. It is of utmost importance to maintain optimal blood pressure control in the oncologic patient to reduce the risk of chemotherapy-induced cardiotoxicity and to decrease the risk of long-term cardiovascular disease.

Hypertension and Prohypertensive Antineoplastic Therapies in Cancer Patients

The development of a wide range of novel antineoplastic therapies has improved the prognosis for patients with a wide range of malignancies, which has increased the number of cancer survivors substantially. Despite the oncological benefit, cancer survivors are exposed to short- and long-term adverse cardiovascular toxicities associated with anticancer therapies. Systemic hypertension, the most common comorbidity among cancer patients, is a major contributor to the increased risk for developing these adverse cardiovascular events. Cancer and hypertension have common risk factors, have overlapping pathophysiological mechanisms and hypertension may also be a risk factor for some tumor types. Many cancer therapies have prohypertensive effects. Although some of the mechanisms by which these antineoplastic agents lead to hypertension have been characterized, further preclinical and clinical studies are required to investigate the exact pathophysiology and the optimal management of hypertension associated with anticancer therapy. In this way, monitoring and management of hypertension before, during, and after cancer treatment can be improved to minimize cardiovascular risks. This is vital to optimize cardiovascular health in patients with cancer and survivors, and to ensure that advances in terms of cancer survivorship do not come at the expense of increased cardiovascular toxicities.

Influence of altitude on hypertension phenotypes and responses to antihypertensive therapy: Review of the literature and design of the INTERVENCION trial

Systemic arterial hypertension constitutes the leading cause of mortality worldwide, and affects people living at different altitudes above sea level (AASL). AASL has a major impact on cardiovascular function and various biologic pathways that regulate blood pressure-related phenotypes, but whether it affects the clinical response to antihypertensive therapy is unknown. The hemodynamic adaptations observed among lowlanders acutely exposed to high altitude (HA) is distinct from those observed among HA dwellers. However, the phenotypic patterns of hypertension and the response to standard antihypertensive agents among adults chronically exposed to different AASL are poorly understood. The authors describe the protocol for the INTERVENCION trial, a randomized clinical trial designed to assess the effects of three first-line antihypertensive monotherapies (a thiazide diuretic, an angiotensin receptor blocker, and a calcium channel blocker) on peripheral and central blood pressure, in-office blood pressure, and ambulatory blood pressure hemodynamics of hypertensive patients living at different AASL (low altitude, intermediate altitude, and high altitude). The primary end point is the reduction in 24-hour brachial systolic blood pressure. The INTERVENCION trial will provide the first clinical trial data regarding the influence of AASL on the response to antihypertensive monotherapy, as well as the hemodynamic characteristics of arterial hypertension at different AASL.

Are prolyl-hydroxylase inhibitors potential alternative treatments for anaemia in patients with chronic kidney disease?

Prolyl-hydroxylase (PHD) inhibitors (PHD-I) are the most appealing drugs undergoing clinical development for the treatment of anaemia in patients with chronic kidney disease. PHD inhibition mimics the exposure of the body to hypoxia and activates the hypoxia-inducible factor system. Among many other pathways, this activation promotes the production of endogenous erythropoietin (EPO) and the absorption and mobilization of iron. PHD-I are given orally and, differing from erythropoiesis-stimulating agents (ESAs), they correct and maintain haemoglobin levels by stimulating endogenous EPO production. Their efficacy and safety are supported by several Phases I and II studies with relatively short follow-up. This class of drugs has the potential to have a better safety profile than ESAs and there may be additional advantages for cardiovascular disease (CVD), osteoporosis and metabolism. However, possible adverse outcomes are feared. These span from the worsening or occurrence of new cancer, to eye complications or pulmonary hypertension. The data from the ongoing Phase III studies are awaited to better clarify the long-term safety and possible advantages of PHD-I.

Drug-Induced Hypertension

Untoward side effects of pharmaceuticals can result in considerable morbidity and expense to the health care system. There is likely a sizable fraction of the hypertensive population with disease either induced or exacerbated by polypharmacy. The elevation of blood pressure in drug-induced hypertension occurs through a variety of mechanisms, most notably, sodium and fluid retention, activation of the renin-angiotensin-aldosterone system, alteration of vascular tone, or a combination of these pathways. Recognition of common medications causing drug-induced hypertension is important to effectively control blood pressure. The epidemiology, pathophysiology, and management of these agents are discussed.

Increased mortality in haemodialysis patients administered high doses of erythropoiesis-stimulating agents: a propensity score-matched analysis

Background

Erythropoiesis-stimulating agents (ESAs) are widely used to treat anaemia in patients with chronic kidney disease. The issue of ESA safety has been raised in multiple studies, with correlates derived for elevated cancer incidence and mortality. Whether these associations are related to ESA dose or the typology of the patient remains obscure.

Methods

A multicentre, observational retrospective propensity score-matched study was designed to analyse the effects of weekly ESA dose in 1679 incident haemodialysis (HD) patients. ESA administration was according to standard medical practice. Patients were grouped as quintiles, according to ESA dose, in order to compare mortality and hospitalization data. Using propensity score matching (PSM), we defined two groups of 324 patients receiving weekly threshold ESA doses of either > or ≤8000 IU.

Results

Kaplan-Meier survival curves indicated significant increases in the risk of mortality in patients administered with high doses of ESAs (>8127.4 IU/week). Multivariate Cox models identified a high ESA dose as an independent predictor for all-cause and cardiovascular (CV) mortality. Moreover, logistic regression models identified high ESA doses as an independent predictor for all-cause, CV and infectious hospitalization. PSM analyses confirmed that weekly ESA doses of >8000 IU constitute an independent predictor of all-cause mortality and hospitalization, even though the adjusted cohort displayed the same demographic features, inflammatory profile, clinical HD parameters and haemoglobin levels.

Conclusions

Our data suggest that ESA doses of >8000 IU/week are associated with an increased risk of all-cause mortality and hospitalization in HD patients.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

Quality of life among patients with moderate to advanced chronic kidney disease in Ghana - a single centre study

Background

The prevalence of chronic kidney disease (CKD) is increasing worldwide and in Africa. Health related quality of life (QOL) has become an essential outcome measure for patients with CKD and end stage renal disease (ESRD). There is growing interest worldwide in QOL of CKD patients but paucity of data in Ghana. This study sought to assess QOL in patients with moderate to advanced CKD (not on dialysis) and establish its determinants.

Methods

We conducted a cross sectional observational study at the renal outpatient clinic at Komfo Anokye Teaching Hospital (KATH). We collected demographic, clinical and laboratory data. A pretested self-administered Research and Development corporation (RAND®) 36-Item Health Survey questionnaire was administered and QOL scores in physical component summary (PCS) and mental component summary (MCS) were computed. Determinants of QOL were established by simple and multiple linear regression. P value of < 0.05 was considered statistically significant.

Results

The study included 202 patients with CKD not on dialysis. There were 118(58.5%) males. Mean age was 46.7 ± 16.2 years. The majority, 165(81.7%) of patients were on monthly salaries of less than GHS 500 (~USD 125). Chronic glomerulonephritis was the most common cause of CKD in 118 (58.5%) patients followed by diabetes mellitus in 40 (19.8%) patients and hypertension in 19 (9.4%) patients. The median serum creatinine was 634.2 μmol/L (IQR 333–1248) and the median eGFR was 7 ml/min/1.73m² (IQR 3–16). The most common stage was CKD stage 5 accounting for 143 (71.1%), followed by CKD stage 4 with 45 (22.4%) of cases and 13 (6.5%) of CKD stage 3. The overall mean QOL score was 40.3 ± 15.4. MCS score was significantly lower than PCS score (37.3 ± 10.8 versus 43.3 ± 21.6, P < 0.001). Multiple linear regression showed that low monthly income (p = 0.002) and low haemoglobin levels (p = 0.003) were predictive of overall mean QOL.

Conclusion

Patients with moderate to advanced CKD had low-income status, presented with advanced disease and had poor QOL. Anaemia and low-income status were significantly associated with poor QOL.

[Cardiovascular complications of doping products]

Doping is the use of a substance that artificially increases an individual's physical ability for competition purpose. Products and methods used in doping are not without risk, especially at cardiovascular level. Here we review the most common doping substances in sport and their cardiovascular consequences.

Beneficial effects of the treatment of iron deficiency on clinical condition, left ventricular function, and quality of life in patients with chronic heart failure

Background: Anemia is now considered as an important contributing factor to the deterioration of chronic heart failure. The present study aimed to assess the effects of intravenous iron therapy on clinical condition, left ventricular function and also quality of life in patients who suffered of chronic heart failure and concomitant iron deficiency. Methods: In this clinical trial, 25 consecutive patients with concomitant chronic heart failure and iron deficiency referred to Shariati hospital in Isfahan, Iran in 2013. After initial clinical, laboratory, and echocardiography assessments, the patients administered 200 mg intravenous Iron per week until compensating iron deficit. Then, all study parameters were assessed again and compared to parameters before the therapeutic intervention. Results: The NYHA class showed a significant improvement after the therapeutic approach. The prevalence of heart failure-related edema was also significantly reduced from 60% before treatment to 48% after that (p = 0.036). The rate of hospitalization was considerably reduced from 42% to 16% (P < 0.001). Moreover, mean 6 minute walk test (6MWT) was increased from 155.18 m to 187.40 m (P < 0.001). Comparing Left Ventricular Ejection Fraction (LVEF) after treatment to figures before the test indicated a significant improvement in this parameter (27.5% versus 33.0%, P = 0.007). The treatment of iron deficiency in this group of subjects got a significant improvement in SF36 total score. Conclusion: In patients with chronic heart failure, the treatment of iron deficiency results in a marked improvement in functional status, ejection fraction, and also quality of life as well as a reduction in need to re-hospitalization, however renal function was deteriorated and thus more pay attention to renal function is necessary. (www.actabiomedica.it)

Activation of the β-common receptor by erythropoietin impairs acetylcholine-mediated vasodilation in mouse mesenteric arterioles

Clinically, erythropoietin (EPO) is known to increase systemic vascular resistance and arterial blood pressure. However, EPO stimulates the production of the potent vasodilator, nitric oxide (NO), in culture endothelial cells. The mechanism by which EPO causes vasoconstriction despite stimulating NO production may be dependent on its ability to activate two receptor complexes, the homodimeric EPO (EPOR2 ) and the heterodimeric EPOR/β-common receptor (βCR). The purpose of this study was to investigate the contribution of each receptor to the vasoactive properties of EPO. First-order, mesenteric arteries were isolated from 16-week-old male C57BL/6 mice, and arterial function was studied in pressure arteriographs. To determine the contribution of each receptor complex, EPO-stimulating peptide (ESP), which binds and activates the heterodimeric EPOR/βCR complex, and EPO, which activates both receptors, were added to the arteriograph chamber 20 min prior to evaluation of endothelium-dependent (acetylcholine, bradykinin, A23187) and endothelium-independent (sodium nitroprusside) vasodilator responses. Only ACh-induced vasodilation was impaired in arteries pretreated with EPO or ESP. EPO and ESP pretreatment abolished ACh-induced vasodilation by 100% and 60%, respectively. EPO and ESP did not affect endothelium-independent vasodilation by SNP. Additionally, a novel βCR inhibitory peptide (βIP), which was computationally developed, prevented the impairment of acetylcholine-induced vasodilation by EPO and ESP, further implicating the EPOR/βCR complex. Last, pretreatment with either EPO or ESP did not affect vasoconstriction by phenylephrine and KCl. Taken together, these findings suggest that acute activation of the heterodimeric EPOR/βCR in endothelial cells leads to a selective impairment of ACh-mediated vasodilator response in mouse mesenteric resistance arteries.

A threshold trajectory was revealed by isolating the effects of hemoglobin rate of rise in anemia of chronic kidney disease

BACKGROUND

To assess cardiovascular risk among various hemoglobin (Hb) rates of rise (RoR) in chronic kidney disease (CKD) patients with anemia who have initiated therapy with erythropoiesis stimulating agents (ESAs).

METHODS

Observational cohort of CKD patients initiating ESA therapy from the Centricity® database, 1990-2011. Proportional hazards models tested the hypothesis that a slower Hb RoR (0 < g/dl/month ⩽ 0.125) is associated with a lower cardiovascular (CV) incidence [composite of fatal/nonfatal myocardial infarction (MI) and stroke] compared with faster RoR (0.125 < g/dl/month ⩽ 2.0, and >2.0 g/dl/month).

RESULTS

A total of 9220 patients receiving ESAs were followed for an average of 3.1 years. Slow (group B) RoR versus medium (group C') and fast (group D') RoR in Hb, throughout all Hb milestones, was associated with lower risk of the composite endpoint [B (slow) versus D' (fast) [hazard ratio (HR) = 0.20 (0.11, 0.39), p < 0.0001]; B versus C' (medium) [HR = 0.34 (0.19, 0.62), p = 0.0004], and C' versus D' [HR = 0.60 (0.42, 0.85), p = 0.005]]. Within achieved Hb milestones, HRs were: B versus D' at milestone ⩾ 14.1 g/dl [HR = 0.17 (0.05, 0.56); p = 0.004] and at milestone 12.6-14.0 [HR = 0.18 (0.07, 0.46), p = 0.0004].

CONCLUSION

Rapid Hb rise is associated with adverse CV outcomes, with markedly lower risk for rates below a threshold trajectory of 0.125 g/dl/month, even with complete correction.

Hypertension in CKD Pregnancy: a Question of Cause and Effect (Cause or Effect? This Is the Question)

Chronic kidney disease (CKD) is increasingly encountered in pregnancy, and hypertension is frequently concomitant. In pregnancy, the prevalence of CKD is estimated to be about 3%, while the prevalence of chronic hypertension is about 5-8%. The prevalence of hypertension and CKD in pregnancy is unknown. Both are independently related to adverse pregnancy outcomes, and the clinical picture merges with pregnancy-induced hypertension and preeclampsia. Precise risk quantification is not available, but risks linked to CKD stage, hypertension, and proteinuria are probably multiplicative, each at least doubling the rates of preterm and early preterm delivery, small for gestational age babies, and related outcomes. Differential diagnosis (based upon utero-placental flows, fetal growth, and supported by serum biomarkers) is important for clinical management. In the absence of guidelines for hypertension in CKD pregnancies, the ideal blood pressure goal has not been established; we support a tailored approach, depending on compliance, baseline control, and CKD stages, with strict blood pressure monitoring. The choice of antihypertensive drugs and the use of diuretics and of erythropoiesis-stimulating agents (ESAs) are still open questions which only future studies may clarify.

"Effects of recombinant human erythropoietin high mimicking abuse doses on oxidative stress processes in rats"

Although many studies highlight how long-term moderate dose of Recombinant Human Erythropoietin (rHuEPO) treatments result in beneficial and antioxidants effects, few studies take into account the effects that short-term high doses of rHuEPO (mimicking abuse conditions) might have on the oxidative stress processes. Thus, the aim of this study was to investigate the in vivo antioxidant activity of rHuEPO, administered for a short time and at high doses to mimic its sports abuse as doping. Male Wistar healthy rats (n=36) were recruited for the study and were treated with three different concentrations of rHuEPO: 7.5, 15, 30μg/kg. Plasma concentrations of erythropoietin, 8-epi Prostaglandin F2α, plasma and urinary concentrations of NOx were evaluated with specific assay kit, while hematocrit levels were analyzed with an automated cell counter. Antioxidant activity of rHuEPO was assessed analyzing the possible variation of the plasma scavenger capacity against hydroxylic and peroxylic radicals by TOSC (Total Oxyradical Scavenging Capacity) assay. Statistical analyses showed higher hematocrit values, confirmed by a statistically significant increase of plasmatic EPO concentration. An increase in plasma scavenging capacity against peroxyl and hydroxyl radicals, in 8-isoprostane plasmatic concentrations and in plasmatic and urinary levels of NOX were also found in all the treated animals, though not always statistically significant. Our results confirm the literature data regarding the antioxidant action of erythropoietin administered at low doses and for short times, whereas they showed an opposite incremental oxidative stress action when erythropoietin is administered at high doses.

An overview on safety issues related to erythropoiesis-stimulating agents for the treatment of anaemia in patients with chronic kidney disease

INTRODUCTION

Erythropoiesis stimulating agents (ESA) are effective drugs, which have been used for decades in patients with chronic kidney disease (CKD) with few side effects. More recently, concern has been raised around their safety, from higher cardiovascular and thrombosis risk to cancer progression and increased mortality.

AREAS COVERED

We made a literature search on PubMed looking for adverse effects of ESA in CKD patients. The topics covered are cardiovascular adverse events, thrombosis, increased mortality, hypertension, cancer progression, diabetic retinopathy, pure red cell aplasia and anaphylactic reactions.

EXPERT OPINION

Concerns around ESA therapy have questioned treatment indications in high-risk CKD patients (those with cancer, diabetes and cardiovascular comorbidities). A more cautious approach has then prevailed. In our opinion, intermediate Hb values (Hb 10-12 g/dl) should be aimed with ESA therapy, being more cautious in high-risk patients. As a consequence, IV iron is administered more frequently. However, excessive iron use may cause iron overload and in rare cases severe anaphylactic reactions. There are expectations of new erythropoietic agents, such as those manipulating the hypoxia-inducible transcription factors (HIF) system. Differing from ESAs, they stimulate the production of endogenous EPO, avoiding over-physiological plasmatic levels.

Pathophysiologic and treatment strategies for cardiovascular disease in end-stage renal disease and kidney transplantations

The inextricable link between the heart and the kidneys predestines that significant cardiovascular disease ensues in the face of end-stage renal disease (ESRD). As a point of fact, the leading cause of mortality of patients on dialysis is still from cardiovascular etiologies, albeit differing in particular types of disease from the general population. For example, sudden cardiac death outnumbers coronary artery disease in patients with ESRD, which is the reverse for the general population. In this review, we will focus on the pathophysiology and treatment options of important traditional and nontraditional risk factors for cardiovascular disease in ESRD patients such as hypertension, anemia, vascular calcification, hyperparathyroidism, uremia, and oxidative stress. The evidence of erythropoietin-stimulating agents, phosphate binders, calcimimetics, and dialysis modalities will be presented. We will then discuss how these risk factors may be changed and perhaps exacerbated after renal transplantation. This is largely due to the immunosuppressive agents that are both crucial yet potentially detrimental in the posttransplant state. Calcineurin inhibitors, corticosteroids, and mammalian target of rapamycin inhibitors, the mainstay of transplant immunosuppression, are all known to increase the risks of developing new onset diabetes as well as the metabolic syndrome. Thus, we need to carefully negotiate between patients' cardiovascular profile and their risks of rejection. Finally, we end by considering strategies by which we may minimize cardiovascular disease in the transplant population, as this modality still confers the highest chance of survival in patients with ESRD.

Pre-treatment considerations in childhood hypertension due to chronic kidney disease

Hypertension (HTN) develops very early in childhood chronic kidney disease (CKD). It is linked with rapid progression of kidney disease, increased morbidity and mortality hence the imperative to start anti-hypertensive medication when blood pressure (BP) is persistently > 90^th percentile for age, gender, and height in non-dialyzing hypertensive children with CKD. HTN pathomechanism in CKD is multifactorial and complexly interwoven. The patient with CKD-associated HTN needs to be carefully evaluated for co-morbidities that frequently alter the course of the disease as successful treatment of HTN in CKD goes beyond life style modification and anti-hypertensive therapy alone. Chronic anaemia, volume overload, endothelial dysfunction, arterial media calcification, and metabolic derangements like secondary hyperparathyroidism, hyperphosphataemia, and calcitriol deficiency are a few co-morbidities that may cause or worsen HTN in CKD. It is important to know if the HTN is caused or made worse by the toxic effects of medications like erythropoietin, cyclosporine, tacrolimus, corticosteroids and non-steroidal anti-inflammatory drugs. Poor treatment response may be due to any of these co-morbidities and medications. A satisfactory hypertensive CKD outcome, therefore, depends very much on identifying and managing these co-morbid conditions and HTN promoting medications promptly and appropriately. This review attempts to point attention to factors that may affect successful treatment of the hypertensive CKD child and how to attain the desired therapeutic BP target.

Our own worst enemy: pharmacologic mechanisms of hypertension

Drug-induced hypertension is often an unrecognized cause of resistant or secondary hypertension. It is defined as hypertension resulting from the unintended effect of a drug or from a drug's antagonistic effect on antihypertensive medications. The main mechanisms of drug-induced hypertension, when categorized broadly, include volume retention and sympathomimetic effects. These mechanisms along with management strategies will be further discussed in this article.

Hypertension in patients with cancer

There is a known association between chemotherapy and radiotherapy for treatment of cancer patients and development or worsening of hypertension. The aim of this article is to review this association. A literature search was conducted for articles reporting this association on the databases PubMed, SciELO and LILACS between 1993 and 2013. There was a high coprevalence of hypertension and cancer, since both diseases share the same risk factors, such as sedentary lifestyle, obesity, smoking, unhealthy diet and alcohol abuse. The use of chemotherapy and adjuvant drugs effective in the treatment of cancer increased the survival rate of these patients and, consequently, increased the incidence of hypertension. We described the association between the use of angiogenesis inhibitors (bevacizumab, sorafenib and sunitinib), corticosteroids, erythropoietin and non-steroidal anti-inflammatory drugs with the development of hypertension. We also described the relationship between hypertension and carotid baroreceptor injury secondary to cervical radiotherapy. Morbidity and mortality increased in patients with cancer and hypertension without proper antihypertensive treatment. We concluded that there is need for early diagnosis, effective monitoring and treatment strategies for hypertension in cancer patients in order to reduce cardiovascular morbidity and mortality.

Hypertension induced by chemotherapeutic and immunosuppresive agents: a new challenge

BACKGROUND

Hypertension is a common adverse effect of certain anti neoplastic therapy. The incidence and severity of hypertension are dependent mainly on the type and the dose of the drug.

METHODS

We reviewed the literature for studies that reported the effect of anti neoplastic agents on blood pressure in patients with malignancies. The medical databases of PubMed, MEDLINE and EMBASE were searched for articles published in English between 1955 and June 2012. The effects of specific agents on blood pressure were analyzed.

RESULTS AND CONCLUSIONS

Hypertension is a prevalent adverse effect of many of the new chemotherapy agents such as VEGF inhibitors. Approximately 30% of patients treated for cancer will have concomitant hypertension, and crucial chemotherapy can sometimes be stopped due to new onset or worsening severe hypertension. The importance of a timely diagnosis and optimal management of HTN in this group of patients is related to the facts that HTN is a well established risk factor for chemotherapy-induced cardiotoxicity and if left untreated, can alter cancer management and result in dose reductions or termination of anti-cancer treatments as well as life-threatening end organ damage.

Posterior reversible encephalopathy syndrome in an adult patient undergoing peritoneal dialysis: a case report and literature review

Background

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity characterized clinically by headache, altered mental status, seizures, visual disturbances, and other focal neurological signs, and radiographically by reversible changes on imaging. A variety of different etiologies have been reported, but the underlying mechanism is thought to be failed cerebral autoregulation. To the best of our knowledge, we report the third known case of PRES in an adult receiving intermittent peritoneal dialysis (PD).

Case presentation

A 23-year-old male receiving PD was brought to hospital after experiencing a generalized seizure. On presentation he was confused and hypertensive. An MRI brain was obtained and showed multiple regions of cortical and subcortical increased T2 signal, predominantly involving the posterior and paramedian parietal and occipital lobes with relative symmetry, reported as being consistent with PRES. A repeat MRI brain obtained three months later showed resolution of the previous findings.

Conclusion

Due to having a large number of endothelium-disrupting risk factors, including hypertension, uremia, and medications known to disrupt the cerebrovascular endothelium, we suggest that those with end-stage renal disease (ESRD) receiving PD are at high risk of developing PRES. Furthermore, we surmise that PRES is likely more prevalent in the ESRD population but is under recognized. Physicians treating those with ESRD must have a high index of suspicion of PRES in patients presenting with neurological disturbances to assure timely diagnosis and treatment.

Effect of erythropoiesis-stimulating agents on blood pressure in pre-dialysis patients

Introduction

Erythropoiesis-Stimulating Agents (ESA) are hypothesized to increase cardiovascular mortality in patients with chronic kidney disease. One of the proposed mechanisms is the elevation of blood pressure (BP) by ESA. Therefore, we aimed to determine whether the use of ESA was associated with antihypertensive treatment and higher BP.

Materials and Methods

In this cohort 502 incident pre-dialysis patients were included who started specialized pre-dialysis care in 25 clinics in the Netherlands. Data on medication including ESA use and dose, co-morbidities and BP were routinely collected every 6 months. Antihypertensive treatment and BP were compared for patients with and without ESA at baseline. Differences in antihypertensive medication and BP during pre-dialysis care were estimated with linear mixed models adjusted for age, sex, body mass index, cardiovascular disease, diabetes mellitus and estimated glomerular filtration rate.

Results

At baseline, 95.6% of patients with ESA were treated with antihypertensive medication and 73.1% of patients without ESA. No relevant difference in BP was found. During pre-dialysis care patients with ESA used 0.77 (95% CI 0.63;0.91) more classes of antihypertensive drugs. The adjusted difference in systolic blood pressure (SBP) was −0.3 (95% CI −2.7;2.0) mmHg and in diastolic blood pressure (DBP) was −1.0 (95% CI −2.1;0.3) mmHg for patients with ESA compared to patients without ESA. Adjusted SBP was 3.7 (95% CI −1.6;9.0) mmHg higher in patients with a high ESA dose compared to patients with a low ESA dose.

Conclusions

Our study confirms the hypertensive effect of ESA, since ESA treated patients received more antihypertensive agents. However, no relevant difference in BP was found between patients with and without ESA, thus the increase in BP seems to be controlled for by antihypertensive medication.

Chronic administration of small nonerythropoietic peptide sequence of erythropoietin effectively ameliorates the progression of postmyocardial infarction-dilated cardiomyopathy

The cardioprotective properties of erythropoietin (EPO) in preclinical studies are well documented, but erythropoietic and prothrombotic properties of EPO preclude its use in chronic heart failure (CHF). We tested the effect of long-term treatment with a small peptide sequence within the EPO molecule, helix B surface peptide (HBSP), that possesses tissue-protective, but not erythropoietic properties of EPO, on mortality and cardiac remodeling in postmyocardial infarction-dilated cardiomyopathy in rats. Starting 2 weeks after permanent left coronary artery ligation, rats received i.p. injections of HBSP (60 µg/kg) or saline two times per week for 10 months. Treatment did not elicit an immune response, and did not affect the hematocrit. Compared with untreated rats, HBSP treatment reduced mortality by 50% (P < 0.05). Repeated echocardiography demonstrated remarkable attenuation of left ventricular dilatation (end-diastolic volume: 41 versus 86%; end-systolic volume: 44 versus 135%; P < 0.05), left ventricle functional deterioration (ejection fraction: -4 versus -63%; P < 0.05), and myocardial infarction (MI) expansion (3 versus 38%; P < 0.05). A hemodynamic assessment at study termination demonstrated normal preload independent stroke work (63 ± 5 versus 40 ± 4; P < 0.05) and arterioventricular coupling (1.2 ± 0.2 versus 2.7 ± 0.7; P < 0.05). Histologic analysis revealed reduced apoptosis (P < 0.05) and fibrosis (P < 0.05), increased cardiomyocyte density (P < 0.05), and increased number of cardiomyocytes in myocardium among HBSP-treated rats. The results indicate that HBSP effectively reduces mortality, ameliorates the MI expansion and CHF progression, and preserves systolic reserve in the rat post-MI model. There is also a possibility that HBSP promoted the increase of the myocytes number in the myocardial wall remote from the infarct. Thus, HBSP peptide merits consideration for clinical testing.

Anaemia management and mortality risk in chronic kidney disease

Renal anaemia is a frequent complication in patients with chronic kidney disease (CKD). Severe anaemia (haemoglobin <90 g/l) is associated with increased risks of mortality and cardiac complications, such as left ventricular hypertrophy and cardiovascular disease, and impaired quality of life. Randomized controlled trials have tested the hypothesis that increasing haemoglobin level using erythropoiesis-stimulating agents (ESAs) lowers these risks and improves quality of life. Use of ESAs to normalize haemoglobin levels (to ≥130 g/l) versus the partial correction of anaemia (to haemoglobin levels of 90-110 g/l) has repeatedly been shown to have no cardiac benefit and to be associated with no incremental improvement in outcomes and quality of life (except fatigue), but has been shown to be associated with an increased risk of cardiovascular events and death. Use of more-intense iron dosing has been proposed in order to reduce ESA dosing but liberal intravenous iron therapy is also associated with complications, and its long-term safety has not yet been adequately investigated. For patients with CKD on dialysis, US medication labels recommend administering ESAs at doses sufficient to avoid transfusions, whereas European and Canadian labels recommend targeting haemoglobin levels of 100-120 g/l and 110-120 g/l, respectively. Treatment of anaemia to haemoglobin levels of 90-110 g/l in patients with CKD accomplishes what we want--a reduced need for transfusions and possible reductions in fatigue, while avoiding high doses of ESA or iron in order to achieve a specific haemoglobin goal.

Systemic and renal haemodynamic changes in renal schemia/reperfusion injury: impact of erythropoietin

The objective of this study was to investigate the effects of erythropoietin (EPO) on systemic and renal hemodynamics in a rat model of renal ischemic/reperfusion (I/R) injury. We used 30 male Sprague-Dawley rats distributed among the following 3 groups (10 rats per group): (i) the sham-operated group, (ii) the control group (I/R injury only), and (iii) the EPO-treated group (I/R injury with 1500 U EPO·(kg body mass)⁻¹ on day 0, and 500 U·kg⁻¹ on days 2 and 4 after ischemia). Renal function, arterial blood pressure (ABP), renal plasma flow (RPF), renal blood flow (RBF), and renal vascular resistance (RVR) were measured on days 1, 2, and 7 after ischemia. The expression of endothelial NO synthase (eNOS) and histopathology of kidney were evaluated on day 7. The contractility of aortic strips was recorded from the different groups. The results show that renal function and histopathology were significantly improved after treatment with EPO. Compared with the control group, the EPO-treated group showed a significant increase in RPF, RBF, haematocrite, ABP, eNOS expression, and a decrease in RVR (p < 0.05).The response of aortic strips to the relaxant effect of acetylcholine was improved in the EPO-treated group. In conclusion, treatment with EPO improves renal function and renal haemodynamics in renal I/R injury, and causes significant rise of ABP and haematocrite value.

Acute hemodynamic effects of erythropoietin do not mediate its cardioprotective properties

Activation of nitric oxide (NO) signaling is considered, at list partially, a mechanistic basis for EPO-induced cardioprotection. Surprisingly, hemodynamic response subsequent to NO activation after EPO administration has never been reported. The objectives of this study were to evaluate the acute hemodynamic and cardiovascular responses to EPO administration, to confirm their NO genesis, and to test the hypothesis that EPO-induced cardioprotection is mediated through cardiovascular changes related to NO activation. In Experiment 1, after 3000 U/kg of rhEPO was administered intravenously to Wistar rats, arterial blood pressure, monitored via indwelling catheter, progressively declined almost immediately until it leveled off 90 minutes after injection at 20% below control level. In Experiment 2 the 25% reduction of mean blood pressure, compared to control group, was observed 2 hours after intravenous injection of either 3000 or 150 U/kg of rhEPO. Detailed pressure–volume loop analyses of cardiac performance (Experiment 3) 2 hours after intravenous injection of human or rat recombinant EPO (3000 U/kg) revealed a significant reduction of systolic function (PRSW was 33% less than control). Reduction of arterial blood pressure and systolic cardiac function in response to rhEPO were blocked in rats pretreated with a non-selective inhibitor of nitric oxide synthase (L-NAME). In Experiment 4, 24 hours after a permanent ligation of a coronary artery, myocardial infarction (MI) measured 26±3.5% of left ventricle in untreated rats. MI in rats treated with 3000 U/kg of rhEPO immediately after coronary ligation was 56% smaller. Pretreatment with L-NAME did not attenuate the beneficial effect of rhEPO on MI size, while MI size in rats treated with L-NAME alone did not differ from control. Therefore, a single injection of rhEPO resulted in a significant, NO-mediated reduction of systemic blood pressure and corresponding reduction of cardiac systolic function. However, EPO-induced protection of myocardium from ischemic damage is not associated with NO activation or NO-mediated hemodynamic responses.

Dose of erythropoiesis-stimulating agents and adverse outcomes in CKD: a metaregression analysis

BACKGROUND

Targeting higher hemoglobin levels with erythropoiesis-stimulating agents (ESAs) to treat the anemia of chronic kidney disease (CKD) is associated with increased cardiovascular risk.

STUDY DESIGN

Metaregression analysis examining the association of ESA dose with adverse outcomes independent of target or achieved hemoglobin level.

SETTING & POPULATION

Patients with anemia of CKD irrespective of dialysis status.

SELECTION CRITERIA FOR STUDIES

We searched MEDLINE (inception to August 2010) and bibliographies of published meta-analyses and selected randomized controlled trials assessing the efficacy of ESAs for the treatment of anemia in adults with CKD, with a minimum 3-month duration. Two authors independently screened citations and extracted relevant data. Individual study arms were treated as cohorts and constituted the unit of analysis.

PREDICTORS

ESA dose standardized to a weekly epoetin alfa equivalent, and hemoglobin levels.

OUTCOMES

All-cause and cardiovascular mortality, cardiovascular events, kidney disease progression, or transfusion requirement.

RESULTS

31 trials (12,956 patients) met the criteria. All-cause mortality was associated with higher (per epoetin alfa-equivalent 10,000-U/wk increment) first-3-month mean ESA dose (incidence rate ratio [IRR], 1.42; 95% CI, 1.10-1.83) and higher total-study-period mean ESA dose (IRR, 1.09; 95% CI, 1.02-1.18). First-3-month ESA dose remained significant after adjusting for first-3-month mean hemoglobin level (IRR, 1.48; 95% CI, 1.02-2.14), as did total-study-period mean ESA dose adjusting for target hemoglobin level (IRR, 1.41; 95% CI, 1.08-1.82). Parameter estimates between ESA dose and cardiovascular mortality were similar in magnitude and direction, but not statistically significant. Higher total-study-period mean ESA dose also was associated with increased rate of hypertension, stroke, and thrombotic events, including dialysis vascular access-related thrombotic events.

LIMITATIONS

Use of study-level aggregated data; use of epoetin alfa-equivalent doses; lack of adjustment for confounders.

CONCLUSIONS

In patients with CKD, higher ESA dose might be associated with all-cause mortality and cardiovascular complications independent of hemoglobin level.

Usefulness of the blood hematocrit level to predict development of heart failure in a community

Current data suggest that increases in hemoglobin may decrease nitric oxide and adversely affect vascular function. In the preclinical setting, these changes could precipitate the development of heart failure (HF). We hypothesized that higher hematocrit (HCT) would be associated with an increased incidence of new-onset HF in the community. We evaluated 3,523 participants (59% women) from the Framingham Heart Study who were 50 to 65 years old and free of HF. Participants were followed prospectively until an HF event, death, or the end of 20 years of follow up. HCT was subdivided into 4 gender-specific categories (women: HCT 36.0 to 40.0, 40.1 to 42.0, 42.1 to 45.0, >45.0; men: 39.0 to 44.0, 44.1 to 45.0, 45.1 to 49.0, >49.0). Gender-pooled multivariable Cox proportional hazards models were used to estimate the association of HCT with incident HF, adjusting for clinical risk factors. During the follow-up period (61,417 person-years), 217 participants developed HF (100 events in women). There was a linear increase in risk of HF across the 4 HCT categories (p for trend = 0.002). Hazards ratios for HF in the low-normal, normal, and high HCT categories were 1.27 (95% confidence interval 0.82 to 1.97), 1.47 (1.01 to 2.15), and 1.78 (1.15 to 2.75), respectively, compared to the lowest HCT category (p for trend <0.0001). Adjustment for interim development of other cardiovascular diseases and restriction of the sample to nonsmokers did not alter the results. In conclusion, higher levels of HCT, even within the normal range, were associated with an increased risk of developing HF in this long-term follow-up study.

Treatment of anemia in chronic kidney disease: known, unknown, and both

Erythropoiesis is a rapidly evolving research arena and several mechanistic insights show therapeutic promise. In contrast with the rapid advance of mechanistic science, optimal management of anemia in patients with chronic kidney disease remains a difficult and polarizing issue. Although several large hemoglobin target trials have been performed, optimal treatment targets remain elusive, because none of the large trials to date have unequivocally identified differences in primary outcome rates or death rates, and because other reported outcomes indicate the potential for harm (rates of stroke, early requirement for dialysis, and vascular access thrombosis) and benefit (reductions in transfusion requirements and fatigue).

Recombinant human erythropoietin treatment protects the cardio-renal axis in a model of moderate chronic renal failure

Chronic kidney disease (CKD) patients develop anemia because of the low kidney erythropoietin (EPO) production, thus promoting cardiovascular complications. The degree of renal insufficiency might determine the moment to start recombinant human erythropoietin (rhEPO) therapy, but the molecular basis for these options deserves better elucidation. This study aimed to clarify the cardio-renal effects of earlier rhEPO therapy in rats with moderate chronic renal failure (CRF). Four groups of rats were evaluated for 15 weeks (control; rhEPO - 50 IU/kg/week; CRF - 3/4 nephrectomy; CRF + rhEPO) to assess renal and hematology data, EPO levels, blood pressure, heart rate, peripheral catecholamines contents, serum-transforming growth factor-β1 (TGF-β1), kidney gene expression of EPO, Caspase 9 (Casp9), and vascular endothelial growth factor (Vegf). This model of moderate CRF showed moderate and corrected anemia, hypertension, tachycardia, sympathetic overactivity, and increased serum TGF-β1 content. The remnant kidney showed a proliferative profile, with hypertrophy, downregulated gene expression of EPO, and upregulated gene expression of Vegf and Casp9. rhEPO treatment promoted erythrocytosis and prevented tachycardia and catecholamines increment, with a rise of serum TGF-β1. Furthermore, the decreased kidney gene expression of EPO and the overexpression of Casp9 were prevented, demonstrating a renoprotective action on the remnant kidney. In conclusion, rhEPO therapy promotes a protective effect on the cardio-renal axis, which might be mainly attributed to its pro-proliferative and anti-apoptotic properties. These findings might recommend its use in earlier stages of CRF, acting as an erythropoiesis stimulating agent, to efficiently correct not only the anemia, one of the major complications in these patients, but also the succeeding adverse cardio-renal effects.

Ten years of meta-analyses on erythropoiesis-stimulating agents in cancer patients

BACKGROUND

Since erythropoiesis-stimulating agents (ESAs) were licensed in 1993, more than 70 randomized controlled trials and more than 20 meta-analyses and systematic reviews on their effectiveness were conducted. Here, we present a systematic review on the meta-analyses of trials evaluating ESAs in cancer patients.

METHODS

We included all published meta-analyses of at least five randomized controlled trials that evaluated the effects of ESAs versus control in patients with any type of cancer or myelodysplastic syndrome.

RESULTS

We included a total of 23 systematic reviews and meta-analyses (16 literature based and 7 based on individual patient data (IPD)) that assessed several outcomes. All 12 meta-analyses reporting on transfusion risks demonstrated that ESAs significantly reduce the risk of transfusions. Eleven meta-analyses (nine based on published data and two on IPD) evaluated thrombovascular events. An increased risk of thrombovascular events was observed in all but two meta-analyses (relative risks (RRs) ranging from 1.57 to 1.69). However, potential reporting and publication bias as well as detection bias call for a cautious interpretation of these results. Survival and mortality were evaluated in 18 meta-analyses, with the observed effect changing over time. While meta-analyses on studies conducted before 2002 showed beneficial effects of ESAs on survival, contrary results, i.e. worsened survival, was seen in meta-analyses including more recent studies.

DISCUSSION

The results from several meta-analyses show that ESAs in cancer patients reduce the risk for red blood cell transfusions and increase the risk for thrombovascular events and mortality. The effect of ESAs on mortality risk in patients receiving chemotherapy remains unclear. In clinical practice, the benefits and risks of ESAs should be carefully considered and decisions should be made based on each patient's situation and preferences.

What is causing the mortality in treating the anemia of chronic kidney disease: erythropoietin dose or hemoglobin level?

PURPOSE OF REVIEW

This article examines the potential mechanisms underlying adverse risk observed in four randomized controlled trials of anemia correction in chronic kidney disease (CKD) patients.

RECENT FINDINGS

The Normal Hematocrit Study, Cardiovascular Risk Reduction by Early Anemia Treatment with Epoetin-beta, Correction of Hemoglobin and Outcomes in Renal Insufficiency, and Trial to Reduce Cardiovascular Events with Aranesp Therapy demonstrate increased risk of mortality and/or cardiovascular complications with targeting of a higher hemoglobin (Hb) in CKD patients. Although a higher Hb level was targeted in these trials, erythropoiesis-stimulating agent (ESA) exposure itself might account for the observed increased risk. This is because, in these trials, achieving a normal or near normal Hb was associated with improved survival and reduced cardiovascular risk. Indeed, it was the 'targeting' of a higher Hb with ESA that seemed to be the problem. Observational data, although conflicting, on the whole provide support for high dosage of ESA being harmful but cannot, by their very nature, prove causality.

SUMMARY

After 20 years of ESA use, is it plausible that ESAs could be toxic? How does one reconcile conflicting observational data with a hypothesis that postulates ESA toxicity? Does the biology of erythropoietin provide a mechanistic explanation? The answers to these questions, among others, will be important in charting a future role for ESAs in treating CKD anemia.

Pharmacotherapy of end-stage renal disease

IMPORTANCE OF THE FIELD

The incidence and prevalence of end-stage renal disease (ESRD) requiring renal replacement therapy (RRT) continues to grow worldwide. ESRD causes significant morbidity and mortality and has enormous financial and personal costs.

AREAS COVERED IN THIS REVIEW

Major electronic databases (including the Cochrane Library, MEDLINE and EMBASE) were searched from 1989 to September 2009 to summarize current pharmacotherapy of ESRD-associated complications in adults receiving maintenance dialysis (hemodialysis or continuous ambulatory peritoneal dialysis). Current guidelines for the treatment of ESRD (e.g., NKF-K/DOQI, KDIGO, and the ERA-EDTA's European Renal Best Practice Guidelines) were included.

WHAT THE READER WILL GAIN

Commonly used pharmacological treatment strategies for chronic arterial hypertension, anemia, iron management, dyslipidemia, hyperglycemia, and for disturbances of bone and mineral metabolism, including hyperphosphatemia and secondary hyperparathyroidism in ESRD, are presented. In addition, the reader will learn that nonadherence to oral medication in ESRD can contribute significantly to excess morbidity and mortality of the dialysis population.

TAKE HOME MESSAGE

Improvements in pharmacotherapy of ESRD may be at least in part counteracted by continuously increasing age and comorbid disease of the dialysis population. Individualized and tailor-made pharmacological management of the ESRD patient remains a challenge for the future.