Wajeh Y. Qunibi

A 1-Year Randomized Trial of Calcium Acetate Versus Sevelamer on Progression of Coronary Artery Calcification in Hemodialysis Patients With Comparable Lipid Control : The Calcium Acetate Renagel Evaluation-2 (CARE-2) Study

BACKGROUND Previous clinical trials showed that progression of coronary artery calcification (CAC) may be slower in hemodialysis patients treated with sevelamer than those treated with calcium-based phosphate binders. Because sevelamer decreases low-density lipoprotein cholesterol (LDL-C) levels, we hypothesized that intensive lowering of LDL-C levels with atorvastatin in hemodialysis patients treated with calcium acetate would result in CAC progression rates similar to those in sevelamer-treated patients. STUDY DESIGN Randomized, controlled, open-label, noninferiority trial with an upper bound for the noninferiority margin of 1.8. SETTING & PARTICIPANTS 203 prevalent hemodialysis patients at 26 dialysis centers with serum phosphorus levels greater than 5.5 mg/dL, LDL-C levels greater than 80 mg/dL, and baseline CAC scores of 30 to 7,000 units assessed by means of electron-beam computed tomography. INTERVENTIONS 103 patients were randomly assigned to calcium acetate, and 100 patients to sevelamer for 12 months to achieve phosphorus levels of 3.5 to 5.5 mg/dL. Atorvastatin was added to achieve serum LDL-C levels less than 70 mg/dL in both groups. OUTCOMES & MEASUREMENTS The primary end point was change in CAC score assessed by means of electron-beam computed tomography. RESULTS After 12 months, mean serum LDL-C levels decreased to 68.8 +/- 22.0 mg/dL in the calcium-acetate group and 62.4 +/- 23.0 mg/dL in the sevelamer group (P = 0.3). Geometric mean increases in CAC scores were 35% in the calcium-acetate group and 39% in the sevelamer group, with a covariate-adjusted calcium acetate-sevelamer ratio of 0.994 (95% confidence interval, 0.851 to 1.161). LIMITATIONS Treatment assignment was not blinded. The 1.8 a priori margin is large, CAC is a surrogate outcome, duration of treatment was short, and dropout rate was high. CONCLUSIONS With intensive lowering of LDL-C levels for 1 year, hemodialysis patients treated with either calcium acetate or sevelamer experienced similar progression of CAC.

Sodium Zirconium Cyclosilicate in Hyperkalemia

BACKGROUND Hyperkalemia (serum potassium level, >5.0 mmol per liter) is associated with increased mortality among patients with heart failure, chronic kidney disease, or diabetes. We investigated whether sodium zirconium cyclosilicate (ZS-9), a novel selective cation exchanger, could lower serum potassium levels in patients with hyperkalemia. METHODS In this multicenter, two-stage, double-blind, phase 3 trial, we randomly assigned 753 patients with hyperkalemia to receive either ZS-9 (at a dose of 1.25 g, 2.5 g, 5 g, or 10 g) or placebo three times daily for 48 hours. Patients with normokalemia (serum potassium level, 3.5 to 4.9 mmol per liter) at 48 hours were randomly assigned to receive either ZS-9 or placebo once daily on days 3 to 14 (maintenance phase). The primary end point was the exponential rate of change in the mean serum potassium level at 48 hours. RESULTS At 48 hours, the mean serum potassium level had decreased from 5.3 mmol per liter at baseline to 4.9 mmol per liter in the group of patients who received 2.5 g of ZS-9, 4.8 mmol per liter in the 5-g group, and 4.6 mmol per liter in the 10-g group, for mean reductions of 0.5, 0.5, and 0.7 mmol per liter, respectively (P<0.001 for all comparisons) and to 5.1 mmol per liter in the 1.25-g group and the placebo group (mean reduction, 0.3 mmol per liter). In patients who received 5 g of ZS-9 and those who received 10 g of ZS-9, serum potassium levels were maintained at 4.7 mmol per liter and 4.5 mmol per liter, respectively, during the maintenance phase, as compared with a level of more than 5.0 mmol per liter in the placebo group (P<0.01 for all comparisons). Rates of adverse events were similar in the ZS-9 group and the placebo group (12.9% and 10.8%, respectively, in the initial phase; 25.1% and 24.5%, respectively, in the maintenance phase). Diarrhea was the most common complication in the two study groups. CONCLUSIONS Patients with hyperkalemia who received ZS-9, as compared with those who received placebo, had a significant reduction in potassium levels at 48 hours, with normokalemia maintained during 12 days of maintenance therapy. (Funded by ZS Pharma; ClinicalTrials.gov number, NCT01737697.).

Effect of Sodium Zirconium Cyclosilicate on Potassium Lowering for 28 Days Among Outpatients With Hyperkalemia The HARMONIZE Randomized Clinical Trial

IMPORTANCE Hyperkalemia is a common electrolyte abnormality that may be difficult to manage because of a lack of effective therapies. Sodium zirconium cyclosilicate is a nonabsorbed cation exchanger that selectively binds potassium in the intestine. OBJECTIVE To evaluate the efficacy and safety of zirconium cyclosilicate for 28 days in patients with hyperkalemia. DESIGN, SETTING, AND PARTICIPANTS HARMONIZE was a phase 3, multicenter, randomized, double-blind, placebo-controlled trial evaluating zirconium cyclosilicate in outpatients with hyperkalemia (serum potassium ≥5.1 mEq/L) recruited from 44 sites in the United States, Australia, and South Africa (March-August 2014). INTERVENTIONS Patients (n = 258) received 10 g of zirconium cyclosilicate 3 times daily in the initial 48-hour open-label phase. Patients (n = 237) achieving normokalemia (3.5-5.0 mEq/L) were then randomized to receive zirconium cyclosilicate, 5 g (n = 45 patients), 10 g (n = 51), or 15 g (n = 56), or placebo (n = 85) daily for 28 days. MAIN OUTCOMES AND MEASURES The primary end point was mean serum potassium level in each zirconium cyclosilicate group vs placebo during days 8-29 of the randomized phase. RESULTS In the open-label phase, serum potassium levels declined from 5.6 mEq/L at baseline to 4.5 mEq/L at 48 hours. Median time to normalization was 2.2 hours, with 84% of patients (95% CI, 79%-88%) achieving normokalemia by 24 hours and 98% (95% CI, 96%-99%) by 48 hours. In the randomized phase, serum potassium was significantly lower during days 8-29 with all 3 zirconium cyclosilicate doses vs placebo (4.8 mEq/L [95% CI, 4.6-4.9], 4.5 mEq/L [95% CI, 4.4-4.6], and 4.4 mEq/L [95% CI, 4.3-4.5] for 5 g, 10 g, and 15 g; 5.1 mEq/L [95% CI, 5.0-5.2] for placebo; P < .001 for all comparisons). The proportion of patients with mean potassium <5.1 mEq/L during days 8-29 was significantly higher in all zirconium cyclosilicate groups vs placebo (36/45 [80%], 45/50 [90%], and 51/54 [94%] for the 5-g, 10-g, and 15-g groups, vs 38/82 [46%] with placebo; P < .001 for each dose vs placebo). Adverse events were comparable between zirconium cyclosilicate and placebo, although edema was more common in the 15-g group (edema incidence: 2/85 [2%], 1/45 [2%], 3/51 [6%], and 8/56 [14%] patients in the placebo, 5-g, 10-g, and 15-g groups). Hypokalemia developed in 5/51 (10%) and 6/56 patients (11%) in the 10-g and 15-g zirconium cyclosilicate groups, vs none in the 5-g or placebo groups. CONCLUSIONS AND RELEVANCE Among outpatients with hyperkalemia, open-label sodium zirconium cyclosilicate reduced serum potassium to normal levels within 48 hours; compared with placebo, all 3 doses of zirconium cyclosilicate resulted in lower potassium levels and a higher proportion of patients with normal potassium levels for up to 28 days. Further studies are needed to evaluate the efficacy and safety of zirconium cyclosilicate beyond 4 weeks and to assess long-term clinical outcomes. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT02088073.

Comparison of Intravenous Iron Sucrose to Oral Iron in the Treatment of Anemic Patients with Chronic Kidney Disease Not on Dialysis

Background: Few studies compare oral to intravenous (IV) iron for managing anemia in patients with chronic kidney disease (CKD) not on dialysis. Methods: We enrolled 96 CKD anemic patients on erythropoietin in a randomized, open-label, multicenter, controlled study. Patients received 29 days of oral FeSO4 (325 mg t.i.d.) or intravenous (IV) iron sucrose (5 doses of 200 mg weekly). Assessments were made up to 14 days after the last dose. Primary endpoints were changes in hemoglobin and ferritin, and clinical success was evaluated from the percent of patients with combined endpoints of rises in hemoglobin/ferritin, hemoglobin/ferritin/TSAT, and hemoglobin/TSAT. Results: There was no significant difference in hemoglobin values between IV and oral therapy. IV iron patients had greater increases in mean serum ferritin (288 ng/ml, p < 0.0001) compared to oral iron patients (–5.1 ng/ml, p = NS). IV iron patients with baseline ferritin <100 ng/ml had a greater increase in hemoglobin (1.4 g/dl) compared to oral iron patients (0.9 g/dl) (p < 0.05). More IV iron patients (54.2%) attained hemoglobin values >11.0 g/dl compared to oral iron patients (31.3%, p = 0.028), and met hemoglobin/ferritin (62.5%), hemoglobin/TSAT (47.9%), hemoglobin/ferritin/TSAT (43.8%), and ferritin/TSAT criteria (54.2%) than oral iron patients (0, 22.9, 0, and 0%, respectively). There were no serious side effects. Conclusions: These CKD patients had increases in both hemoglobin and ferritin following IV iron therapy, whereas those treated with oral iron had increases in hemoglobin without increases in iron stores. Iron sucrose, given weekly as 200 mg IV push over 5 min is an effective and safe anemia treatment in this population.

A randomized controlled trial comparing intravenous ferric carboxymaltose with oral iron for treatment of iron deficiency anaemia of non-dialysis-dependent chronic kidney disease patients

Background. Iron deficiency is a common cause of anaemia and hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) in non-dialysis-dependent chronic kidney disease (ND-CKD) patients. Current intravenous iron agents cannot be administered in a single high dose because of adverse effects. Ferric carboxymaltose, a non-dextran parenteral iron preparation, can be rapidly administered in high doses. Methods. This open-label trial randomized 255 subjects with glomerular filtration rates ≤ 45 mL/min/1.73 m2, haemoglobin ≤ 11 g/dL, transferrin saturation ≤ 25%, ferritin ≤ 300 ng/mL, and stable ESA dose to either intravenous ferric carboxymaltose 1000 mg over 15 min (with up to two additional doses of 500 mg at 2-week intervals) or oral ferrous sulphate 325 mg thrice daily for a total of 195 mg elemental iron daily for 56 days. Results. In the modified intent-to-treat population, the proportion of subjects achieving a haemoglobin increase ≥ 1 g/dL at any time was 60.4% with ferric carboxymaltose and 34.7% with oral iron (P < 0.001). At Day 42, mean increase in haemoglobin was 0.95 ± 1.12 vs 0.50 ± 1.23 g/dL (P = 0.005), mean increase in ferritin was 432 ± 189 ng/mL vs 18 ± 45 ng/mL (P < 0.001) and mean increase in transferrin saturation was 13.6 ± 11.9% vs 6.1 ± 8.1% (P < 0.001). Treatment-related adverse events were significantly fewer with ferric carboxymaltose than with oral iron (2.7% and 26.2%, respectively; P < 0.0001). Conclusions. We conclude that 1000 mg ferric carboxymaltose can be rapidly administered, is more effective and is better tolerated than oral iron for treatment of iron deficiency in ND-CKD patients.

Serologic association of human herpesvirus eight with posttransplant Kaposi's sarcoma in Saudi Arabia

BACKGROUND This study investigates the association between human herpesvirus eight (HHV8) and Kaposis sarcoma (KS), the most common cancer occurring in renal transplant recipients in Saudi Arabia. METHODS A cross-sectional study of seroreactivity to HHV8 antigens in posttransplant KS patients from a tertiary care hospital in Riyadh, Saudi Arabia, and in control subjects without KS was conducted. Seroreactivity rates were determined using immunoblotting assays to detect antibodies to two lytic cycle HHV8 antigens: p40, an antigen found in infected cells, and sVCA, an HHV8-encoded small viral capsid antigen expressed in Escherichia coli. RESULTS Antibodies to HHV8 p40 and sVCA were present in a significantly higher proportion of renal transplant patients with KS (13 of 14 patients) compared to renal transplant patients without KS (5 of 18; P<0.001) and compared to other control individuals (6 of 44; P<0.001). HHV8 seroreactivity was more common among patients with renal failure (28%) than among other control groups (7%). CONCLUSIONS The serologic results provide evidence of a strong association between HHV8 and posttransplant KS in Saudi Arabia.

Reducing the Burden of Cardiovascular Calcification in Patients with Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have a higher burden of atherosclerotic coronary artery disease compared with age- and gender-matched individuals with normal renal function. Cardiovascular calcification (CVC), a marker of atherosclerosis, is also more prevalent in these patients and is associated with serious clinical consequences. The pathogenesis of CVC is complex and includes factors that promote calcification and others that inhibit calcification. Thus, multiple therapeutic interventions should be used simultaneously to reduce the burden of calcification in patients with CKD. Thus far, interventional attempts have focused on curtailing the effects of factors that promote calcification such as management of known traditional factors for atherosclerotic coronary artery disease and on adopting specific approaches to normalize mineral metabolism, deliver adequate dialysis, and control serum cholesterol level. By contrast, interventions that may bolster the effects of inhibitors of calcification have not yet been studied well but are beginning to attract attention. Ideally, the goal of interventions is not only to slow or halt progression of calcification but also to reverse pre-existing calcification. Whether this goal is achievable is not currently known. This review examines the potential of various therapeutic interventions in reducing the CVC burden in patients with CKD. Moreover, the review is intended to stimulate more research in this area because the efficacy of these interventions has not been examined in controlled clinical trials.

Ferric carboxymaltose in patients with iron-deficiency anemia and impaired renal function: the REPAIR-IDA trial

BACKGROUND Iron-deficiency anemia in non-dialysis-dependent chronic kidney disease (NDD-CKD) frequently requires parenteral iron replacement, but existing therapies often require multiple administrations. We evaluated the efficacy and cardiovascular safety of ferric carboxymaltose (FCM), a non-dextran parenteral iron permitting large single-dose infusions, versus iron sucrose in patients with iron-deficiency anemia and NDD-CKD. METHODS A total of 2584 participants were randomized to two doses of FCM 750 mg in one week, or iron sucrose 200 mg administered in up to five infusions in 14 days. The primary efficacy endpoint was the mean change to highest hemoglobin from baseline to Day 56. The primary composite safety endpoint included all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, unstable angina, congestive heart failure, arrhythmias and hyper- and hypotensive events. RESULTS The mean hemoglobin increase was 1.13 g/dL in the FCM group and 0.92 g/dL in the iron sucrose group (95% CI, 0.13-0.28). Similar results were observed across all subgroups, except Stage 2 CKD. More subjects in the FCM group achieved a hemoglobin increase of ≥ 1.0 g/dL between baseline and Day 56 (48.6 versus 41.0%; 95% CI, 3.6-11.6%). There was no significant difference between FCM and iron sucrose recipients with respect to the primary composite safety endpoint, including the major adverse cardiac events of death, myocardial infarction, or stroke. A significant difference in the number of protocol-defined, predominantly transient hypertensive episodes was observed in the FCM group. CONCLUSIONS Two 750-mg infusions of FCM are a safe and effective alternative to multiple lower dose iron sucrose infusions in NDD-CKD patients with iron-deficiency anemia.

The efficacy and safety of current intravenous iron preparations for the management of iron-deficiency anaemia: a review

Iron-deficiency anaemia (IDA) is a major health problem worldwide, but responds well to iron supplementation. New approaches are leading to more effective management of this condition. Iron deficiency (ID) is usually suspected in at-risk patients with declining haemoglobin (Hb) levels and then confirmed by measuring serum ferritin levels and transferrin saturation. However, regular monitoring of these iron indicators and other laboratory parameters in susceptible individuals may lead to early recognition of falling iron stores and facilitate pre-emptive therapeutic intervention before anaemia develops. Patients with ID are commonly prescribed oral iron preparations because of convenience and low cost. However, the efficacy of these agents is limited by their reduced absorption rate and gastrointestinal side-effects. Alternatively, treatment of IDA in patients requiring erythropoiesis-stimulating agents (ESAs) is more predictably achieved by use of intravenous (i.v.) iron. Unfortunately, the development of serious adverse events (SAEs) from high molecular-weight iron dextran has led to reluctance to use i.v. iron in the treatment of IDA. Similarly, but to a much lesser extent, low molecular-weight iron dextran is associated with a number of SAEs, including allergic or anaphylactic reactions. The introduction of second-generation i.v. iron formulations, including iron sucrose and ferric gluconate, was clearly an improvement over i.v. iron dextran. These formulations proved to be effective in the management of IDA and are not associated with the serious allergic reactions encountered with i.v. iron dextran. For these reasons, use of these preparations became more widespread in the treatment of IDA across a wide range of clinical conditions. An important advantage of i.v. iron over oral iron is that it may bypass hepcidin actions by directly loading transferrin and making iron available to macrophages. Despite a reduction in the short-term risks, there is still concern about the potential for long-term toxicity of i.v. iron use (e. g. atherosclerosis development, infection and increased mortality). The association of atherosclerosis with iron overload remains unclear. Alternatively, the relative risk for mortality or hospitalization from infection in patients undergoing haemodialysis (HD) who received i.v. iron was shown not to be higher than that observed in the overall HD population. Indeed, doses of i.v. iron up to 400 mg/month were associated with improved patient survival. Second-generation i.v. iron formulations are more frequently used for treating IDA than i.v. iron-dextran in patients with various chronic conditions including those with chronic kidney disease. In the latter, IDA should be corrected before initiation of ESA therapy, as iron deficiency can lead to hyporesponsiveness to ESA. However, a major limitation of the second-generation i.v. iron agents is that they cannot be administered in large doses and the typical 1000 mg therapy requires several clinic visits. Thus, there is a need for an i.v. iron agent that can be safely administered in a single dose of 1000 mg of iron and therefore requires less frequent clinic visits. This limitation has now been overcome with the introduction of newer i.v. iron preparations. Ferric carboxymaltose offers effective and rapid correction of IDA by overcoming the limitations observed with previous i.v. iron preparations. This agent has been shown to be effective and well tolerated in a number of randomized controlled trials in a variety of chronic conditions.

Calcium salts in the treatment of hyperphosphatemia in hemodialysis patients.

Purpose of reviewHyperphosphatemia in patients with end-stage renal disease leads to secondary hyperparathyroidism and renal osteodystrophy, and is independently associated with mortality risk. How hyperphosphatemia increases mortality risk is unknown but it may promote cardiovascular calcification. It is recommended that dialysis patients be treated to maintain normal serum phosphorus. Although calcium-based phosphate binders are cost-effective, their long-term safety has been questioned because of their postulated role in progression of cardiovascular calcification. In this regard, sevelamer hydrochloride has been recommended as an alternative phosphate binder. In this review, we will examine these issues and provide rational guidelines for the use of calcium-based phosphate binders. Recent findingsResults from the calcium acetate Renagel evaluation study indicate that calcium acetate is more effective than sevelamer in controlling serum phosphorus and calcium x phosphorus product in hemodialysis patients. However, in the Treat-to-Goal study dialysis patients treated with sevelamer had less progression of coronary and aortic calcification than patients treated with calcium-containing binders. The mechanism underlying the slower rate of progression of cardiovascular calcification in sevelamer-treated patients remains uncertain but may relate to decreased calcium loading or to dramatic reductions in LDL cholesterol. SummaryAt present, evidence incriminating calcium-containing phosphate binders in the progression of cardiovascular calcification in end-stage renal disease remains largely circumstantial. As calcium acetate is more efficacious and cost-effective than sevelamer, it remains an accepted first-line drug. Treatment with sevelamer hydrochloride should be considered for patients with persistent hypercalcemia during calcium-based binder therapy despite appropriate adjustment of vitamin D therapy.