Serum Phosphorus and Pill Burden Among Hemodialysis Patients Prescribed Sucroferric Oxyhydroxide: One-Year Follow-Up on a Contemporary Cohort

Purpose

In prior analyses of real-world cohorts of hemodialysis patients switched from one phosphate binder (PB) to sucroferric oxyhydroxide (SO), SO therapy has been associated with improvements in serum phosphorus (sP) and reductions in daily PB pill burden. To characterize how SO initiation patterns have changed over time, we examined the long-term effectiveness of SO in a contemporary (2018–2019) cohort.

Patients and Methods

Adult Fresenius Kidney Care hemodialysis patients first prescribed SO monotherapy as part of routine care between May 2018 and May 2019 (N = 1792) were followed for 1 year. All patients received a non-SO PB during a 91-day baseline period before SO prescription. Mean PB pills/day and laboratory parameters were compared before and during SO treatment. Results were divided into consecutive 91-day intervals (Q1–Q4) and analyzed using linear mixed-effects regression and Cochran’s Q test. These results were contrasted with findings from a historical (2014–2015) cohort (N = 530).

Results

The proportion of patients achieving sP ≤5.5 mg/dl increased after switching to SO (from 27.0% at baseline to 37.8%, 45.1%, 44.7%, and 44.0% at Q1, Q2, Q3, and Q4, respectively; P < 0.0001 for all). The mean daily PB pill burden decreased from a baseline of 7.7 to 4.4, 4.6, 4.8, and 4.9, respectively, across quarters (P < 0.0001 for all). Patients in the contemporary cohort had improved sP control (27.0% achieving sP ≤5.5 mg/dl vs 17.7%) and lower daily PB pill burden (mean 7.7 vs 8.5 pills/day) at baseline than those in the historical cohort. Overall use of active vitamin D was similar between cohorts, although higher use of oral active vitamin D (63.9% vs 15.7%) and lower use of IV active vitamin D lower (23.4% vs 74.2%) was observed in the contemporary cohort.

Conclusion

Despite evolving treatment patterns, switching to SO resulted in improved sP control with fewer pills per day in this contemporary hemodialysis cohort.

Calcimimetic use in US hemodialysis facilities in first 2 years after the launch of etelcalcetide: A descriptive analysis of real-world clinical practice and outcomes

INTRODUCTION

This study described control of parathyroid hormone (PTH), phosphorus, and corrected calcium in adults initiating calcimimetics in small dialysis organizations after the introduction of etelcalcetide.

METHODS

This retrospective study using Visonex Clarity electronic health records between October 1, 2017, and December 31, 2019, identified adults ≥ 18 years of age receiving in-center hemodialysis as either a cinacalcet or etelcalcetide initiator based on their first calcimimetic use in 2018 (index date) with no prior calcimimetic use in the 3 months preindex date. Patients were stratified by PTH at index date and were followed for 15 months. Subcohorts of patients who were persistent on a single calcimimetic for 15 months and of patients who had their calcimimetic changed from cinacalcet to etelcalcetide were also analyzed.

FINDINGS

A total of 677 patients initiated cinacalcet and 711 initiated etelcalcetide. Mean PTH (pg/ml), phosphorus, and corrected calcium (mg/dl) at baseline were 864, 5.9, and 9.3 for cinacalcet and 804, 5.9, and 9.4 for etelcalcetide, respectively. During follow-up, the proportion of initiators considered in-target (monthly average PTH < 600) increased from 48% to 62% with cinacalcet and from 56% to 86% with etelcalcetide in the baseline PTH 600 to < 800 subgroup; increased from 30% to 64% with cinacalcet and 31% to 59% with etelcalcetide among those with baseline PTH 800 to < 1000; and increased from 14% to 41% with cinacalcet and 12% to 58% with etelcalcetide among those with baseline PTH ≥1000. A similar pattern was observed for persistent users (n = 646). For patients changed from cinacalcet to etelcalcetide (n = 183), the proportion of patients considered in-target increased from 22% in the month prior to the treatment change to 51% in Month 6 postchange.

DISCUSSION

Patients initiating calcimimetics at lower baseline PTH had better biochemical control than patients starting at higher PTH. Patients changed from cinacalcet to etelcalcetide had improvements in PTH control postchange.

MO571PRACTICE PATTERNS ON THE MANAGEMENT OF SECONDARY HYPERPARATHYROIDISM IN THE UNITED STATES: RESULTS FROM A MODIFIED DELPHI PANEL

Background and Aims

The 2017 Kidney Disease Improving Global Outcomes (KDIGO) Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD) guidelines inform clinical practice for the management of secondary hyperparathyroidism (SHPT) internationally; however, many recommendations lacked high or moderate clinical evidence as defined by KDIGO. An expert panel was convened to establish clinical consensus for the current management of SHPT in the United States (US).

Method

The panel comprised 10 US healthcare providers (HCPs; [6 nephrologists, 1 surgeon, 1 nurse practitioner, 1 pharmacist, 1 dietician]) and 1 patient. HCP panelists participated in a modified Delphi process over 3 phases, addressing 126 questions based on a review of the literature and published guidelines. The threshold for consensus was 66%. In phases 1 and 2, panelists anonymously completed electronic surveys considering a ‘typical’ patient with SHPT unless otherwise specified. In phase 1, panelists answered 126 questions based on their own knowledge and experiences. In phase 2, panelists were reminded of their answers to closed-ended questions that did not achieve consensus in phase 1 and were asked if they would change their responses in light of the most common response. For open-ended questions, they were asked if they agreed with summary statements that captured the most common answers. Phase 3 was an unblinded virtual meeting where panelists reviewed the consensus reached in phases 1 and 2, and through active discussion, resolved those questions that had not reached consensus. The patient completed a separate electronic survey, which complemented key points in the HCP survey, and provided perspective during the virtual meeting.

Results

All 11 panelists completed the entire modified Delphi process. Sixty-three out of 126 (50%) and 116/126 (92.1%) questions reached consensus or addressed practice-specific information not requiring consensus by the end of phase 1 and 2, respectively; all questions reached consensus by the end of phase 3, including modification of 2 questions and the addition of 1 question. The panel unanimously agreed that SHPT treatment is often started too late and suggested additional markers for early identification of patients requiring treatment are needed. Serum levels of calcium, phosphate, and parathyroid hormone (PTH) should be monitored starting at CKD stage G3a at intervals of every 6 months, 3–6 months for CKD G3b, and at least every 3 months at CKD G4 and above. Thresholds for interventions could not be defined in absolute terms for all patients due to patient-and practice-specific factors. However, in patients on dialysis, serum levels of phosphate &gt; 5.5 mg/dL (1.8 mmol/L) and calcium &gt; 9.5 mg/dL (2.4 mmol/L), warrant increased monitoring and consideration of therapeutic interventions. Serum intact PTH &gt; 300 pg/mL (32 pmol/L) typically indicates a need for SHPT treatment, with a consensus preferred target of 150–300 pg/mL (16–32 pmol/L); patients on dialysis were considered out of PTH target at ≥ 8 times the upper limit of normal (&gt; 520 pg/mL [55 pmol/L] intact PTH). HCPs were concerned about vascular calcification in all patients with CKD 3a–G5D. The panel reached consensus on the use of several SHPT interventions, including a consensus preference for the intravenous calcimimetic etelcalcetide over the oral calcimimetic cinacalcet in appropriate in-center dialysis patients requiring PTH-lowering therapy; cinacalcet was agreed to be first-line therapy in appropriate patients on home dialysis (Table 1). Factors such as formularies and dialysis center protocols were recognized to influence therapeutic choices.

Conclusion

Ten US HCPs reached consensus on many aspects of SHPT management, further defining therapeutic strategies and highlighting the need to be proactive. While the panel expressed evidenced-based preferences for certain therapies, factors such as cost and dialysis center protocols may affect decision making.

Racial/Ethnic Differences in Barriers to Kidney Transplant Evaluation among Hemodialysis Patients

BACKGROUND

Only a small percentage of dialysis patients receive a transplant and this is particularly the case for racial/ethnic minorities. Our objective was to identify barriers to initial transplant evaluation in our dialysis centers.

METHODS

We conducted a survey of adult hemodialysis patients from 4 dialysis units in the Denver Metro area in 2016. Participants completed an 11-item survey with demographic information and questions regarding time on dialysis, if a provider ever spoke to them about transplant, and whether they had been evaluated for a transplant. Reasons for not having an evaluation were explored. Descriptive statistics, chi-square analyses, and multivariate analyses were used to examine the responses.

RESULTS

A total of 167 patients completed the survey (response rate 63.9%). The majority of participants were male and were Hispanic (49%) or Non-Hispanic black (31.7%). Of these, 140 patients (84.0%) reported discussing kidney transplantation with their doctor but only 53% reported having a transplant evaluation. After adjustment for age, gender, and time on dialysis, significantly fewer blacks reported having an evaluation than Non-Hispanic whites or Hispanics (43.4 vs. 57.7% [whites] and 59.7% [Hispanics], p = 0.03). The most frequent responses of the patients who had not been evaluated were the following: not referred by their provider (46%), did not know how to proceed (43.4%), or did not understand the benefits (39.5%) or transplant process (38.2%). Compared to Non-Hispanic whites, blacks and Hispanics reported less understanding of the benefits and process of transplant.

CONCLUSION

Timely referral by providers and improved kidney transplantation education may reduce disparities in access to kidney transplantation.

Serum Bicarbonate Is Associated with Heart Failure in the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Low serum bicarbonate concentrations are associated with mortality and kidney disease progression. Data regarding associations between bicarbonate and cardiovascular disease (CVD) are scarce.

METHODS

We performed a cohort study of 6,229 adult participants from the Multi-Ethnic Study of Atherosclerosis, a community-based cohort free of CVD at baseline. Serum bicarbonate was measured at baseline. Cardiovascular outcomes were defined as: (1) subclinical CVD (left ventricular mass [LVM] and aortic pulse pressure [PP] measured at baseline), (2) incident atherosclerotic cardiovascular events (CVE; composite of myocardial infarction, resuscitated cardiac arrest, stroke, coronary heart disease death, and stroke death), and (3) incident heart failure.

RESULTS

During a median (interquartile range) follow-up of 8.5 (7.7-8.6) years, 331 (5.3%) participants had an incident CVE and 174 (2.8%) developed incident heart failure. We stratified analyses by use of diuretics because we observed a significant interaction between diuretic use and bicarbonate with study outcomes. Among diuretic nonusers, with adjustment, bicarbonate ≥25 mEq/L was associated with an estimated 3.0 g greater LVM (95% CI 0.5-5.0) and 1.0 mm Hg higher aortic PP (95% CI 0.4-2.0) compared to bicarbonate 23-24 mEq/L. Each 1 mEq/L of bicarbonate increase was associated with a 13% higher risk of incident heart failure (hazards ratio 1.13, 95% CI 1.01-2.11). Among diuretic users, higher bicarbonate was not associated with CVD. Bicarbonate was not associated with incident atherosclerotic CVE irrespective of diuretic use.

CONCLUSION

Among nonusers of diuretics in a large community-based study, higher serum bicarbonate concentrations are associated with subclinical CVD and new heart failure.

Mineral Metabolites, Angiotensin II Inhibition and Outcomes in Advanced Chronic Kidney Disease

BACKGROUND

Evidence suggests that the renin-angiotensin-aldosterone system (RAAS) interacts with the vitamin D-fibroblast growth factor 23-Klotho axis. We investigated whether circulating mineral metabolism markers modify outcomes in response to RAAS inhibition in subjects with advanced chronic kidney disease (CKD).

METHODS

In this retrospective cohort study, we analyzed the association of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) use with all-cause mortality and dialysis initiation among 1,753 subjects (1,099 CKD, estimated glomerular filtration rate 18 ± 6 ml/min/1.73 m(2) and 654 end-stage renal disease [ESRD]) from the Homocysteine in Kidney and End Stage Renal Disease (HOST) study. A propensity score analysis accounted for indication bias and Cox regression models adjusted for mineral metabolism markers.

RESULTS

Mean follow-up was 3.2 years; 714 (41%) subjects died and 615 (56%) initiated dialysis. In adjusted analyses, all subjects treated with ACEI/ARB had a significantly lower hazard of death (hazards ratio (HR) 0.81, 95% CI 0.70-0.95, p = 0.007). Those with CKD not on dialysis and treated with ACEI/ARB trended toward a lower hazard of dialysis initiation (HR 0.86, 95% CI 0.73-1.01, p = 0.06). The association with mortality did not differ by level of mineral metabolism marker (p for interaction >0.16); however, the relationship with dialysis initiation differed according to the median serum phosphorus level (p for interaction <0.001).

CONCLUSIONS

RAAS inhibition was associated with decreased all-cause mortality independent of disordered mineral metabolism among mostly male HOST subjects with advanced CKD and ESRD. However, among those with CKD not requiring dialysis, the renoprotection associated with RAAS inhibition was attenuated by higher serum phosphorus levels. Further studies are needed to confirm this association.

A rare presentation of ischemic pseudomembranous colitis due to Escherichia coli O157:H7

Escherichia coli Ol57:H7 infection ranges from mild diarrheal illness to severe hemorrhagic colitis but may rarely be complicated by pseudomembranous colitis and/or necrosis. Herein, we report a sporadic case of ischemic E. coli Ol57:H7 pseudomembranous colitis in an adult that occurred during a national outbreak of E. coli Ol57:H7 in the United States.

Distal stem design and the torsional stability of cementless femoral stems

In cementless hip arthroplasty, the fit between the implant and the endosteal cavity is a critical determinant of implant stability. Although cementless implants may be stabilized through proximal fit within the metaphysis, many surgeons rely on diaphyseal fixation to provide the necessary resistance to rotational forces, especially in revision hip arthroplasty. The cross-sectional design of the femoral stem at the level of the femoral isthmus was investigated with respect to its effect on the rotational stability of the bone-stem interface. Four cross-sectional designs--a fluted stem, a finned stem, a porous-coated stem, and a slotted fluted stem--were implanted in 12 cadaveric femurs and loaded in torsion. A knurled stem, cemented into each specimen at the conclusion of testing, acted as a control stem. The torque required to cause 100 microns of displacement at the bone stem-interface ranged from 13.7 +/- 0.8 N-m with the porous-coated design to 30.1 +/- 3.7 N-m with the fluted design (P < .0001). Intermediate values of 19.5 +/- 1.4 and 19.9 +/- 2.3 N-m were observed with the finned and slotted fluted designs, respectively. In all of the cemented control stems, failure occurred at the bone-cement interface at an average torque of 34.0 +/- 3.0 N-m. Statistical analysis demonstrated that the porous-coated, finned, and slotted fluted designs were all significantly weaker in torsion than the cemented control stem; however, there was no significant difference between the torsional resistance of the solid fluted (unslotted) and cemented stems.(ABSTRACT TRUNCATED AT 250 WORDS)