Iron deficiency and supplementation in heart failure

Non-anaemic iron deficiency (NAID) is a strategic target in cardiovascular medicine because of its association with a range of adverse effects in various conditions. Endeavours to tackle NAID in heart failure have yielded mixed results, exposing knowledge gaps in how best to define 'iron deficiency' and the handling of iron therapies by the body. To address these gaps, we harness the latest understanding of the mechanisms of iron homeostasis outside the erythron and integrate clinical and preclinical lines of evidence. The emerging picture is that current definitions of iron deficiency do not assimilate the multiple influences at play in patients with heart failure and, consequently, fail to identify those with a truly unmet need for iron. Additionally, current iron supplementation therapies benefit only certain patients with heart failure, reflecting differences in the nature of the unmet need for iron and the modifying effects of anaemia and inflammation on the handling of iron therapies by the body. Building on these insights, we identify untapped opportunities in the management of NAID, including the refinement of current approaches and the development of novel strategies. Lessons learned from NAID in cardiovascular disease could ultimately translate into benefits for patients with other chronic conditions such as chronic kidney disease, chronic obstructive pulmonary disease and cancer.

Plasma erythropoietin level and heart failure in patients undergoing peritoneal dialysis: a cross-sectional study

Background

Renal anemia is the important complication in patients undergoing peritoneal dialysis (PD), and heart failure (HF) is the important complication in patients on dialysis. Decreasing endogenous erythropoietin (EPO) in patients with chronic kidney disease is a major cause of renal anemia. On the other hand, high levels of EPO have been associated with the prognosis of patients with chronic HF. The association between plasma EPO and HF in patients on PD remains unclear. This study was designed to test our hypothesis that the plasma EPO level in patients on PD was associated with the markers of HF.

Methods

We investigated 39 patients undergoing PD at our hospital. We measured plasma EPO before erythropoiesis-stimulating agent (ESA) administration at the regular outpatient visits and then at 2 weeks after the final dose of ESA was administered and investigated the clinical factors. We estimated the correlations between the plasma EPO and the other parameters, and constructed univariate and multivariate logistic regression models for the risk for HF to estimate the effectiveness of plasma EPO and other factors on HF treatment in patients undergoing PD.

Results

The plasma EPO concentration was positively correlated with the ESA dose and negatively correlated with serum ferrum, transferrin saturation, and body mass index and showed no correlation with other factors, such as the New York Heart Association (NYHA) classification and ferritin level. In univariate analysis, the factors significantly associated with HF risk were N-terminal pro-brain natriuretic peptide (NT-pro BNP), cardiothoracic ratio (CTR), serum creatinine (Cr), serum beta 2 microglobulin, dialysate dose, left ventricular mass index, left ventricular end-systolic diameter, left ventricular end-diastolic diameter, and weekly Kt/V. We performed a multivariate analysis with NT-pro BNP, Cr, and CTR, and all three factors were significant in the analysis.

Conclusion

The plasma EPO level in patients undergoing PD was positively correlated with the monthly ESA dose and was not significant as a marker of HF, as judged with the NYHA classification. Therefore, the plasma EPO level may not be a useful marker for HF in patients undergoing PD.

Shortened red blood cell age in patients with end-stage renal disease who were receiving haemodialysis: a cross-sectional study

Background

The causes of anaemia in patients with end-stage renal disease include a relative deficiency in erythropoietin production and complex clinical conditions. We aimed to investigate the underlying mechanisms of anaemia in patients with end-stage renal disease who were undergoing maintenance dialysis by measuring erythrocyte creatine levels.

Methods

In a cross-sectional study, we evaluated 69 patients with end-stage renal disease who were receiving haemodialysis (n = 55) or peritoneal dialysis (n = 14). Erythrocyte creatine level, a quantitative marker of mean red blood cell (RBC) age, was measured.

Results

The mean RBC age was significantly shorter in the haemodialysis group than in the peritoneal dialysis group (47.7 days vs. 59.8 days, p < 0.0001), although the haemoglobin levels were comparable between the groups. A Spearman correlation coefficient analysis revealed that shortened RBC age positively correlated with transferrin saturation (r = 0.54), ferritin level (r = 0.47), and haptoglobin level (r = 0.39) but inversely related with reticulocyte (r = − 0.36), weekly doses of erythropoiesis-stimulating agents (ESAs; r = − 0.62), erythropoietin resistance index (r = − 0.64), and intradialytic ultrafiltration rate (r = − 0.32).

Conclusions

Shortened RBC age was observed in patients who were receiving maintenance haemodialysis and was associated with iron deficiency, greater haptoglobin consumption, higher ESA requirements, and poor erythropoietin responsiveness, as well as with greater intradialytic fluid extraction.

Efficacy and Long-Term Safety of C.E.R.A. Maintenance in Pediatric Hemodialysis Patients with Anemia of CKD

BACKGROUND AND OBJECTIVES

The study was conducted to identify a conversion factor for switching from previous erythropoiesis-stimulating agents (ESAs) to continuous erythropoietin receptor activator-methoxy polyethylene glycol-epoetin beta (C.E.R.A.) and to document the efficacy and long-term safety of C.E.R.A. in pediatric patients with anemia of CKD undergoing hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this open-label, multicenter study, patients aged 6-17 years, with stable chronic anemia of CKD, undergoing hemodialysis received C.E.R.A. every 4 weeks, at a starting dose determined by previous weekly epoetin alfa/beta or darbepoetin dosing. After a 16-week dose-titration and a 4-week evaluation period, patients with stable hemoglobin could enter a 1-year optional safety extension.

RESULTS

A total of 64 patients were enrolled. A conversion factor (4 µg every 4 weeks for each weekly dose of 125 IU epoetin alfa/beta or 0.55 µg darbepoetin) was identified that allowed patients to maintain hemoglobin within target levels on switching to C.E.R.A. from another ESA. Using this conversion factor, the adjusted mean change in hemoglobin from baseline to evaluation was -0.09 g/dl (95% confidence interval, -0.45 to 0.26); 81% of patients maintained hemoglobin within 10.0-12.0 g/dl and 75% maintained hemoglobin within 1.0 g/dl of baseline. Results were consistent across age groups (6-11 and 12-17 years) and previous ESA. Thirty-seven patients entered the safety extension period and 17 completed 73 weeks of treatment. Most withdrawals were for kidney transplantation. A total of 70% of patients had hemoglobin within 10.0-12.0 g/dl at last observation, and 62% were within ±1.0 g/dl of baseline. Safety was similar to studies in adult patients, with no new signal detected.

CONCLUSIONS

Using a defined conversion factor, 4-weekly C.E.R.A. was efficacious in maintaining hemoglobin levels in pediatric patients with stable anemia of CKD undergoing hemodialysis, switching from maintenance treatment with epoetin alfa/beta or darbepoetin. Safety was consistent with the known C.E.R.A. safety profile in adults.

Early response to erythropoiesis-stimulating agents in non-dialysis chronic kidney disease patients

BACKGROUND

Renal anemia complicated with chronic kidney disease is usually treated with erythropoiesis-stimulating agents (ESAs). However, few studies have compared the early response of hemoglobin (Hb) to different kinds of ESAs.

METHODS

The effects of three types of ESAs-epoetin alfa or beta (EPO), darbepoetin alfa (DPO), and epoetin beta pegol (EPObp)-on renal anemia were followed in 416 pre-dialysis chronic kidney disease (CKD) patients. After the initial 12-week administration of ESAs, ΔHb/ESA dose/kg was calculated as an index of efficacy of each ESA. Furthermore, independent variables associated with ΔHb/ESA dose/kg (dependent variable) were determined using multiple linear regression analysis. The ten independent variables selected for analysis were: presence of diabetic nephropathy, estimated glomerular filtration rate (eGFR), Hb, albumin, iron (Fe), transferrin saturation (TSAT), ferritin, phosphate (P), intact parathyroid hormone (iPTH), and C-reactive protein.

RESULTS

The efficacy of DPO and EPObp were similar and higher than EPO. TSAT was most strongly correlated with ΔHb/EPO dose/kg in all three types of ESAs. Other significant independent factors were Hb, albumin, P, iPTH, and diabetic nephropathy in the EPO group, eGFR in the DPO group, and Fe in the EPObp group. The adjusted coefficient of determination (R (2)) ranged from 0.415 to 0.520 in the three ESA groups.

CONCLUSIONS

The study results suggest that TSAT is the best predictor of the initial 12-week responsiveness to ESA, irrespective of the type. Variables not investigated in this study also affect responsiveness to ESA in Japanese pre-dialysis CKD patients.