Regional Variation in Hemoglobin Distribution Among Individuals With CKD: the ISN International Network of CKD Cohorts

Introduction

Despite recognized geographic and sex-based differences in hemoglobin in the general population, these factors are typically ignored in patients with chronic kidney disease (CKD) in whom a single therapeutic range for hemoglobin is recommended. We sought to compare the distribution of hemoglobin across international nondialysis CKD populations and evaluate predictors of hemoglobin.

Methods

In this cross-sectional study, hemoglobin distribution was evaluated in each cohort overall and stratified by sex and estimated glomerular filtration rate (eGFR). Relationships between candidate predictors and hemoglobin were assessed from linear regression models in each cohort. Estimates were subsequently pooled in a random effects model.

Results

A total of 58,613 participants from 21 adult cohorts (median eGFR range of 17-49 ml/min) and 3 pediatric cohorts (median eGFR range of 26-45 ml/min) were included with broad geographic representation. Hemoglobin values varied substantially among the cohorts, overall and within eGFR categories, with particularly low mean hemoglobin observed in women from Asian and African cohorts. Across the eGFR range, women had a lower hemoglobin compared to men, even at an eGFR of 15 ml/min (mean difference 5.3 g/l, 95% confidence interval [CI] 3.7-6.9). Lower eGFR, female sex, older age, lower body mass index, and diabetic kidney disease were all independent predictors of a lower hemoglobin value; however, this only explained a minority of variance (R2 7%-44% across cohorts).

Conclusion

There are substantial regional differences in hemoglobin distribution among individuals with CKD, and the majority of variance is unexplained by demographics, eGFR, or comorbidities. These findings call for a renewed interest in improving our understanding of hemoglobin determinants in specific CKD populations.

International practice patterns of dyslipidemia management in patients with chronic kidney disease under nephrology care: is it time to review guideline recommendations?

BACKGROUND

In contrast to guidelines related to lipid therapy in other areas, 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines recommend conducting a lipid profile upon diagnosis of chronic kidney disease (CKD) and treating all patients older than 50 years without defining a target for lipid levels. We evaluated multinational practice patterns for lipid management in patients with advanced CKD under nephrology care.

METHODS

We analyzed lipid-lowering therapy (LLT), LDL- cholesterol (LDL-C) levels, and nephrologist-specified LDL-C goal upper limits in adult patients with eGFR < 60 ml/min from nephrology clinics in Brazil, France, Germany, and the United States (2014-2019). Models were adjusted for CKD stage, country, cardiovascular risk indicators, sex, and age.

RESULTS

LLT treatment differed significantly by country, from 51% in Germany to 61% in the US and France (p = 0.002) for statin monotherapy. For ezetimibe with or without statins, the prevalence was 0.3% in Brazil to 9% in France (< 0.001). Compared with patients not taking lipid-lowering therapy, LDL-C was lower among treated patients (p < 0.0001) and differed significantly by country (p < 0.0001). At the patient level, the LDL-C levels and statin prescription did not vary significantly by CKD stage (p = 0.09 LDL-C and p = 0.24 statin use). Between 7-23% of untreated patients in each country had LDL-C ≥ 160 mg/dL. Only 7-17% of nephrologists believed that LDL-C should be < 70 mg/dL.

CONCLUSION

There is substantial variation in practice patterns regarding LLT across countries but not across CKD stages. Treated patients appear to benefit from LDL-C lowering, yet a significant proportion of hyperlipidemia patients under nephrologist care are not receiving treatment.

D-lactate is a promising biomarker for the diagnosis of periprosthetic joint infection

Introduction

Reliable biomarkers for the diagnosis of periprosthetic joint infection (PJI) are of paramount clinical value. To date, synovial fluid leukocyte count is the standard surrogate parameter indicating PJI. As D-lactate is almost solely produced by bacteria, it represents a promising molecule in the diagnostic workflow of PJI evaluation. Therefore, the purpose of this study was to assess the performance of synovial fluid D-lactate for diagnosing PJI of the hip and knee.

Materials and Methods

These are preliminary results of a prospective multicenter study from one academic center. Seventy-two consecutive patients after total hip arthroplasty (THA) or total knee arthroplasty (TKA) were prospectively included. All patients received a joint aspiration in order to rule out or confirm PJI, which was diagnosed according to previously published institutional criteria. Synovial fluid D-lactate was determined spectrophotometrically at 450 nm. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance.

Results

Eighteen patients (25%) were diagnosed with PJI and 54 patients (75%) were classified as aseptic. Synovial fluid D-lactate showed a sensitivity of 90.7% (95% CI: 79.7%-96.9%) and specificity of 83.3% (95% CI: 58.6%-96.4%) at a cut-off of 0.04 mmol/L. The median concentration of D-lactate was significantly higher in patients with PJI than in those with aseptic conditions (0.048 mmol/L, range, 0.026-0.076 mmol/L vs. 0.024 mmol/L, range, 0.003-0.058 mmol/L, p < 0.0001). The predominat microogranisms were staphylococci, followed by streptococci and gram-negative bacteria.

Conclusion

D-lactate bears a strong potential to act as a valuable biomarker for diagnosing PJI of the hip and knee. In our study, a cutoff of 0.04 mmol/L showed a comparable sensitivity to synovial fluid leukocyte count. However, its specificity was higher compared to conventional diagnostic tools. The additional advantages of D-lactate testing are requirement of low synovial fluid volume, short turnaround time and low cost.

Patiromer utilization in patients with advanced chronic kidney disease under nephrology care in Germany

Background

Hyperkalemia (HK) is a frequent condition in patients with chronic kidney disease (CKD) that is associated with high morbidity and mortality. Patiromer has recently been introduced as a potassium binder. Data on patiromer use in patients with CKD in the real-world setting in Europe are lacking. We describe time to discontinuation and changes in serum potassium levels among German CKD stage 3-5 patients starting patiromer.

Methods

Duration of patiromer use was estimated by Kaplan-Meier curve, starting at patiromer initiation and censoring for death, dialysis, transplant or loss to follow-up. Serum potassium levels and renin-angiotensin-aldosterone system inhibitor (RAASi) use are described at baseline and during follow-up, restricted to patients remaining on patiromer.

Results

We identified 140 patiromer users within our analysis sample [81% CKD stage 4/5, 83% receiving RAASi, and median K+ 5.7 (5.4, 6.3) mmol/L]. Thirty percent of patiromer users had prior history of polystyrene sulfonate use. Overall, 95% of patiromer users stayed on treatment past 1 month, with 53% continuing for over a year. Mean serum potassium levels decreased after patiromer initiation and remained stable under treatment during follow-up (up to 180 days). Among these patients, 73%-82% used RAASis during the time periods before and after patiromer initiation, with no obvious trend indicating discontinuation.

Conclusion

Real-world evidence of patiromer use in Germany shows that, in line with what has been observed in clinical trials, patients on patiromer have a reduction in serum potassium when used long-term. Moreover, most patients on patiromer do not discontinue treatment prior to 1 year after initiation.

FC 103: Matched Control Study on Applied Long-Term Anti-Thrombotic Therapies and Clinical Outcome of Atrial Fibrillation in HD-Patients Based on German Network Data

BACKGROUND AND AIMS

Hemodialysis (HD) patients (pts) with atrial fibrillation (AF) are at high risk for cardiovascular events, severe bleeding and rapid vascular/valvular calcification. Thus, antivitamin-K based oral anticoagulation (VK-OAC) for HD patients is debated, since prospective trials are missing and US register studies are often limited to 3–6 months OAC use. We studied AF risk-factors, long-term antithrombotic therapies and clinical outcomes in a large German HD cohort.

METHOD

We analysed pseudonymized benchmarking data in a German out-patient dialysis center network (Verband Deutsche Nierenzentren, DN) based on quarterly electronically transmitted data. Diagnoses coded by ‘International Classification of Diseases (ICD)’ and ‘Anatomical Therapeutical Chemical (ATC)’ drug codes of adult HD patients 2013–2018.

RESULTS

In 2013, 2753 (18%) of 15 682 HD-pts had AF as coded diagnosis. Baseline CHA2DS2-VASc (4.0/1.5 mean/SD) and HAS-BLED (3.2/0.9) risk-scores indicated high risk for embolism and bleeding. Charlson Comorbidity Index (CCI) was high (6.4/2.8) and median observation was 2.1 years (range 0.01–6 years).

Beside HD-related heparin, four main OAC approaches were applied: no active therapy, VK-OAC+/-aspirin/clopidogrel (VK-OAC+/-Asp/Clop), heparin-based therapy (heparin+/-Asp/Clop) or 1–2 antithrombocyte drugs (Asp/Clop). A total of 959 pts (35%) changed therapy, but 1794 pts (65%) had no change in OAC regime during the 6 year study period and were used for final therapy-related outcome analysis (Table 1).

Both AF risk-scores overestimated de-novo events. Total 6-year event rate was low (7.5%; &lt;1.3% per year) and comparable for all anticoagulant therapies, especially for cerebral ischemic events (2.8%; range 1.2–3.7; NS). All three antithrombotic therapies had similar overall events as without active therapy (7.6 versus 7.3%), including cerebral adverse events (ischemic: 3.0 versus 2.6%; bleeding: 0.7 versus 0.6%; NS).

Survival (Kaplan–Meier) was analysed for matched controls by propensity-score based on mortality risk factors in multivariate Cox regression: age (HR 1.05), sex (female HR 0.78), CCI (HR 1.07) and albumin (HR 0.93). Six-year mortality rates were high (63%) and matched analysis showed significant lower survival (P &lt; 0.001) without anticoagulant (median 1.8 years) or on heparin-based therapy (1.7 years) than on Asp/Clop (2.9 years) or VK-OAC based therapy (2.8 years). This relation was similar for subgroups on age, CCI or changed therapy.

CONCLUSION

Our large study showed that baseline CHA2DS2-VASc and HAS-BLED scores had no predictive value for clinical events in HD pts with AF.

Cerebral ischemic event rates over 6 years were low (&lt;0.7%/year) and similar for all three antithrombotic therapies and even no active therapy, suggesting major benefit of regular dialysis-related heparin supply.

Since median survival on Asp/Clop is similar to VK-OAC therapy and even 1 year better than on no active or heparin-based therapy, we conclude that antithrombotic therapy in HD patients with AF can effectively be done with Asp/Clop and VK-OAC should be avoided. For future prospective trials, we recommend to apply Asp/Clop as first-line control therapy evaluating new direct-acting oral anticoagulants (DOAK) and/or interventional approaches (i.e. left atrial appendage closure) in HD patients with AF.

FC005: Pace CKD: Qualitative and Quantitative Insights into the Economic Burden of CKD on Patients and Carers

BACKGROUND AND AIMS

Chronic kidney disease (CKD) is likely to significantly affect the lives of patients and their carers, including increasing the economic burden. The relationship between CKD progression and these life impacts remains poorly characterized. The patient, carer and economic burden (PaCE) CKD study aims to enhance understanding of patient and carer experiences of CKD, including financial impact.

METHOD

In-depth, semi-structured, qualitative interviews were conducted with 20 patients with CKD and 19 informal carers in Australia, France, Germany, Italy, the UK and the USA. Participants were asked about their experiences with CKD and the associated economic burden.

A quantitative online survey is ongoing, with 150–200 patients and 75–100 carers anticipated to participate per country. A Work Productivity and Activity Impairment (WPAI) questionnaire for patients and caregivers is being used to understand and estimate the financial burden of CKD on patients and caregivers. Patients are also being asked about their disease background, including the stage of CKD and treatment history.

RESULTS

In total, 20 patients and 19 carers participated in the qualitative interviews, with at least 3 patients and 3 carers included from each country.

Eleven patients were male. Most patients were 75 years old or younger (18/20; overall range 30–81 years, overall mean 61.7 years). Patients reported their CKD stages: 3/20 stage 5; 2/20 stage 4–5; 2/20 stage 4; 2/20 stage 3–4; 8/20 stage 3; 1/20 stage 2; and 2/20 unknown. A third of patients underwent dialysis (7/20), including at least one patient from each country. Nine patients were working full- or part-time.

Carers were 30–90 years old (mean 55.1 years), predominantly women (13/19) and were primarily relatives of the patient (8/19 partner, 5/19 daughter/son, 2/19 daughter-/son-in-law). More than half of the carers were employed (13/19 employed, 5/19 unemployed/retired, 1/19 unknown). Carer support varied between 4 and 35 h/week. Support included activities of daily living, visits to the hospital and emotional/psychological support; support was noted as more critical for patients with later-stage CKD.

The degree of financial burden experienced by patients and carers varied between countries, potentially reflecting differences in local healthcare systems; however, the impact of reduced work hours on finances was consistent across all countries. Both patients and carers reported a loss of work hours, and in some cases, participants reported that they had to stop working. Patients who were employed reported lower productivity, and carers reported taking days off work without pay. Expenses related to the cost of managing CKD, including dietary needs, medical aids and hospital transport, further increased the economic burden. The extent of these impacts varied depending on the severity of CKD.

Results from the quantitative survey will be presented at the congress.

CONCLUSION

Responses from qualitative interviews suggest that CKD increases the financial burden for both patients and carers, particularly as the disease progresses. When combined with data from the quantitative survey, these findings will provide important insights into the economic burden of CKD for patients and carers.

With the exception of the Hill-Sachs interval, CT and MRI show no significant differences in the diagnostic value of the HSL measurement regardless of the measurement technique

PURPOSE

The aim of the current study was to compare the diagnostic precision and reliability of different methods in measuring Hill-Sachs lesions (HSLs) using MRI and CT.

METHODS

A total of 80 consecutive patients with a history of anterior shoulder instability were retrospectively included. The preoperative CT and MRI scans of the affected shoulders were analysed. To investigate the ability of the Franceschi grading, Calandra classification, Richards, Hall, and Rowe grading scale, Flatow percentage and "glenoid track" assessment according to Di Giacomo et al. to quantify the extent of humeral bone loss, the results of each measurement method obtained with MRI were compared with those achieved with CT. In addition, the intra- and inter-rater reliabilities of each measurement method using CT and MRI were calculated and compared.

RESULTS

A significant difference was found between CT and MRI in the determination of the Hill-Sachs interval (HSI) (p = 0.016), but not between the results of any of the other measurement techniques. With the exceptions of the Franceschi grade and Calandra classification, all measurement methods showed good or excellent intra- and inter-rater reliabilities for both MRI and CT.

CONCLUSIONS

While the determination of the HSI with MRI was more accurate, all other analysed techniques for measuring the amount of humeral bone loss showed similar diagnostic precision. With regard to the intra- and inter-rater reliabilities, all measurement techniques analysed, with the exception of the Franceschi and Calandra classifications, provided good to very good reliabilities with both CT and MRI.

LEVEL OF EVIDENCE

III.

Potential Surrogate Outcomes for Kidney Failure in Advanced CKD: Evaluation of Power and Predictive Ability in CKDopps

Rationale & Objective

Potential surrogate end points for kidney failure have been proposed in chronic kidney disease (CKD); however, they must be evaluated to ensure accurate, powerful, and harmonized research, particularly among patients with advanced CKD. The aim of the current study was to investigate the power and predictive ability of surrogate kidney failure end points in a population with moderate-to-advanced CKD.

Study Design

Analysis of longitudinal data of a large multinational CKD observational study (Chronic Kidney Disease Outcomes and Practice Patterns Study).

Setting & Participants

CKD stage 3-5 patients from Brazil, France, Germany, and the United States.

Outcomes

Reaching an estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m² or eGFR decline of ≥40%, and composite end points of these individual end points.

Analytical Approach

Each end point was used as a time-varying indicator in the Cox model to predict the time to kidney replacement therapy (KRT; dialysis or transplant) and was compared by the number of events and prediction accuracy.

Results

8,211 patients had a median baseline eGFR of 27 mL/min/1.73 m² (interquartile range, 21-36 mL/min/1.73 m²) and 1,448 KRT events over a median follow-up of 2.7 years (interquartile range, 1.2-3.0 years). Among CKD stage 4 patients, the eGFR < 15 mL/min/1.73 m² end point had higher prognostic ability than 40% eGFR decline, but the end points were similar for CKD stage 3 patients. The combination of eGFR < 15 mL/min/1.73 m² and 40% eGFR decline had the highest prognostic ability for predicting KRT, regardless of the CKD stage. Including KRT in the composite can increase the number of events and, therefore, the power.

Limitations

Variable visit frequency resulted in variable eGFR measurement frequency.

Conclusions

The composite end point can be useful for CKD progression studies among patients with advanced CKD. Harmonized use of this approach has the potential to accelerate the translation of new discoveries to clinical practice by identifying risk factors and treatments for kidney failure.

Sex-Specific Differences in Mortality and Incident Dialysis in the Chronic Kidney Disease Outcomes and Practice Patterns Study

Introduction

More men than women start kidney replacement therapy (KRT) although the prevalence of chronic kidney disease (CKD) is higher in women than men. We therefore aimed at analyzing sex-specific differences in clinical outcomes among 8237 individuals with CKD in stages 3 to 5 from Brazil, France, Germany, and the United States participating in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps).

Methods

Fine and Gray models, evaluating the effect of sex on time to events, were adjusted for age, Black race (model A); plus diabetes, cardiovascular disease, albuminuria (model B); plus estimated glomerular filtration rate (eGFR) slope during the first 12 months after enrollment and first eGFR after enrollment (model C).

Results

There were more men than women at baseline (58% vs. 42%), men were younger than women, and men had higher eGFR (28.9 ± 11.5 vs. 27.0 ± 10.8 ml/min per 1.73 m²). Over a median follow-up of 2.7 and 2.5 years for men and women, respectively, the crude dialysis initiation and pre-emptive transplantation rates were higher in men whereas that of pre-KRT death was more similar. The adjusted subdistribution hazard ratios (SHRs) between men versus women for dialysis were 1.51 (1.27–1.80) (model A), 1.32 (1.10–1.59) (model B), and 1.50 (1.25–1.80) (model C); for pre-KRT death, were 1.25 (1.02–1.54) (model A), 1.14 (0.92–1.40) (model B), and 1.15 (0.93–1.42) (model C); for transplantation, were 1.31 (0.73–2.36) (model A), 1.44 (0.76–2.74) (model B), and 1.53 (0.79–2.94) (model C).

Conclusion

Men had a higher probability of commencing dialysis before death, unexplained by CKD progression alone. Although the causal mechanisms are uncertain, this finding helps interpret the preponderance of men in the dialysis population.

Serum Biomarkers of Iron Stores Are Associated with Increased Risk of All-Cause Mortality and Cardiovascular Events in Nondialysis CKD Patients, with or without Anemia

BACKGROUND

Approximately 30%-45% of patients with nondialysis CKD have iron deficiency. Iron therapy in CKD has focused primarily on supporting erythropoiesis. In patients with or without anemia, there has not been a comprehensive approach to estimating the association between serum biomarkers of iron stores, and mortality and cardiovascular event risks.

METHODS

The study included 5145 patients from Brazil, France, the United States, and Germany enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study, with first available transferrin saturation (TSAT) and ferritin levels as exposure variables. We used Cox models to estimate hazard ratios (HRs) for all-cause mortality and major adverse cardiovascular events (MACE), with progressive adjustment for potentially confounding variables. We also used linear spline models to further evaluate functional forms of the exposure-outcome associations.

RESULTS

Compared with patients with a TSAT of 26%-35%, those with a TSAT ≤15% had the highest adjusted risks for all-cause mortality and MACE. Spline analysis found the lowest risk at TSAT 40% for all-cause mortality and MACE. Risk of all-cause mortality, but not MACE, was also elevated at TSAT ≥46%. Effect estimates were similar after adjustment for hemoglobin. For ferritin, no directional associations were apparent, except for elevated all-cause mortality at ferritin ≥300 ng/ml.

CONCLUSIONS

Iron deficiency, as captured by TSAT, is associated with higher risk of all-cause mortality and MACE in patients with nondialysis CKD, with or without anemia. Interventional studies evaluating the effect on clinical outcomes of iron supplementation and therapies for alternative targets are needed to better inform strategies for administering exogenous iron.

MO470PATIROMER PHARMACOUTILIZATION IN REAL-WORLD GERMAN CKD PATIENTS WITH MODERATELY TO SEVERELY REDUCED EGFR

Background and Aims

Hyperkalemia (HK) (serum K&gt;5.0 mEq/L) is a chronic condition in patients with chronic kidney disease (CKD) associated with high morbidity and mortality, and it is a frequent reasons for renin angiotensin aldosterone inhibition (RAASi) discontinuation. Patiromer is a non-absorbed, sodium-free, K+ binder that has been shown to reduce serum K+ in patients with HK, and thereby enable RAASi therapy, which is supported by randomized trial evidence. The description of patiromer utilization in patients with moderate to advanced CKD in the real-world setting in Europe is lacking. The objective of this analysis was to describe predictors of patiromer initiation and time to discontinuation among CKD patients using contemporary (April 2018-October 2020) data from German participants in CKD Outcomes and Practice Patterns Study (CKDopps).

Method

We identified 136 patiromer users (116 with matching K measurement) during the observation period. Patients with eGFR &lt;60ml/min/1.73m2 and a serum potassium ≥4mEq/L who never initiated patiromer during the follow up were used as a comparison. We used the most recent lab and drug use information available within the 6-month period prior to baseline, which was defined as either first use of patiromer, April 1, 2018, or entry into the PDOPPS study. The median time between the most recent K+ measurement and baseline was 45 days for non-patiromer users and 4 days for patiromer users. Logistic regression models were used to test associations between patient factors and whether the patient was in the patiromer initiation group or the comparison group. Time on patiromer was estimated using a Kaplan-Meier curve, censoring for death, dialysis, transplantation, or loss of follow-up.

Results

Patiromer was prescribed to ≥2 patients in 11 clinics, one patient in 19 clinics, and zero patients in 57 clinics. Patients prescribed patiromer had lower eGFR (23.2 [15.8, 28.6] vs 36.9 [27.7, 46.3]ml/min) and higher serum K levels (5.6 [5.4, 6.1] vs 4.6 [4.3, 5.0]ml/min). There were no major differences according to patiromer use in other demographic, clinical, and biochemical characteristics. Despite the differences in serum K, use of RAAS inhibitors was similar in patiromer users (83%) versus non-users (80%). Thirty three percent of patiromer users were prescribed polystyrene sulfonate (SPS) before patiromer initiation. In a multiple logistic regression models (including serum K, CKD stage, gender, age, prescription of RAASi, diabetes, coronary artery disease, heart failure), patiromer use was strongly associated more advanced CKD stage (independently of high serum K), with odds ratios of initiation &gt;3 for CKD stage 4 or 5 versus CKD stage 3. Among new users, 90% of patients had active prescription at 30 days and about one-half had active prescription at one year (Figure).

Conclusion

The main predictors of Patiromer initiation were advanced CKD stage and hyperkalemia. Treatment decisions did not appear to be based on other patient or clinical characteristics. Patiromer was often prescribed to patients already receiving alternative HK treatment (SPS), suggesting use for chronic hyperkalemia rather than response to acute event. Further analysis with a larger population and measurements of K+ before and after patiromer initiation may improve the understanding of its pharmacoutilization in moderate to advanced CKD.

FC 106HIGHER MAGNESIUM DIALYSATE CONCENTRATION SIGNIFICANTLY IMPROVE SURVIVAL AND CEREBRAL OUTCOME IN HD-PATIENTS WITH ATRIAL FIBRILLATION: LONG-TERM STUDY ON GERMAN NETWORK DATA

Background and Aims

Hemodialysis (HD) patients with atrial fibrillation (AF) are at high risk for cardio-vascular events, severe bleeding and rapid vascular/valvular calcification. Thus, higher than low standard dialysate Mg (d-Mg) may improve outcome by less arrhythmic or calcification impact, but clinical data are missing. Our study evaluated applied d-Mg, risk-factors and antithrombotic therapies on long-term outcome in a large representative German HD-cohort.

Method

We used pseudonymized benchmarking data (2013-2018) of 16226 adult chronic HD patients (informed consent) from DNeV dialysis network. Diagnoses were coded by “International Classification of Diseases (ICD)” and drugs via “Anatomical Therapeutical Chemical (ATC)” codes. Risk scores (Carlson Comorbidity Index=CCI, CHA2DS2-VASc and HAS-BLED) were tested for de-novo outcome prediction.

Results

At baseline, 2752 (17%) HD-patients had coded AF. CHA2DS2-VASc (4.0/SD1.5) and HAS-BLED (3.2/0.9) estimated high risk for embolism/bleeding. Standard dialysate-Mg (sd-Mg; 0.5 mmol/L) was used by 1317 (48%), d-Mg 0.75 had 331 (12%), d-Mg &gt;1.0 had 134 (5%) and 970 (35%) patients changed from 0.5 to 0.75 during the study period (change group). Median study time was 2.1 yrs (Range=R: 0.01–6 yrs.).

Overall 6-yr mortality was high (63%; Kaplan Meier median survival of 2.9 yrs. Unchanged d-Mg levels were significantly (p&lt;0.02) related to survival: Patients on sd-Mg had lower median survival (2.7 yrs.) than on 0.75 (3.1 yrs; p&lt;0.05) or &gt;1.0 (3.4 yrs; p=0.02). The change group had the same survival (3.1 yrs) as the 0.75 group (p&lt;0.03 vs. 0.5). Cox-Regression (multivariate, sd-Mg=ref.) revealed d-Mg &gt;1.0 (hazard ratio=HR 0.74), d-Mg 0.75 (HR 0.79), serum albumin (HR 0.93), age (HR 1.04) and CCI (HR 1.06) as independently related to mortality (p=0.002). Sd-Mg had higher (p&lt;0.05) cerebral adverse events (5.2%) than 0.75 (1.8%) and &gt;1.0 group (3.7%).

Apart from dialysis-related heparin-supply four main approaches regarding anti-coagulation were identified: No therapy, VK-OAC, Heparin or only Aspirin/Clopidogrel (Asp/Clop): VK-OAC and Asp/Clop had same median survival (2.8 yrs) both better (p&lt;0.001) than no therapy (1.3 yrs) or Heparin (1.6 yrs), but VK-OAC had higher bleeding rates (6.4%; p&lt;0.001) than Asp/Clop (3.5%). Cerebral adverse events (3,8% in 6 yrs) were much lower than estimated and similar for all four regimes (R: 3.9-4.4%).

Conclusion

Use of higher d-Mg in HD-patients with AF significantly improved survival and cerebral outcome, is a feasible cost-effective approach and has more relative impact than well established survival risk-factors such as age, comorbidity (=CCI) and serum albumin. Our data warrant prospective trials comparing higher d-Mg levels with anti-thrombotic drugs and/or left atrial appendage occlusion for better evidence. So far, therapy of HD patients with AF should base on implementation of higher d-Mg, prefer Asp/Clop as best anti-thrombotic drugs and clearly avoid more harmful VK-OAC.

MO495UNDERSTANDING INTERNATIONAL VARIATION IN KIDNEY FAILURE INCIDENCE: IMPACT OF DISPARITIES IN RAAS INHIBITOR PRESCRIPTION AND BLOOD PRESSURE CONTROL

Background and Aims

Blood pressure (BP) control and renin-angiotensin-aldosterone system (RAAS) blockade are key measures to slow CKD progression, and the achievement of targets for these measures vary greatly across countries. We sought to evaluate to what extend this might explain international variations in kidney failure incidence.

Method

We used data from the CKD Outcomes and Practice Patterns Study (CKDopps), a cohort study of adult patients recruited from national samples of nephrology clinics. Patients with CKD G3 or G4, from Brazil (n=498), France (n=2702), Germany (n=2314), and the US (n=905) were included. Those neither with hypertension nor with albuminuria were excluded (n=103). We assessed systolic BP and RAAS inhibitor prescription at baseline, and their association with time to kidney failure, defined as an estimated glomerular filtration rate (eGFR) &lt; 15 ml/min/1.73m² or kidney replacement therapy initiation. Death was treated as a competing event. Cox proportional-hazards model was used to estimate cause-specific hazard ratios (cs-HR) and 95% confidence intervals (CI) for kidney failure according to country, before and after adjusting for systolic BP and RAAS inhibitor prescription, as well as demographics, and known risk factors for CKD progression.

Results

Median age (years) ranged from 67 in Brazil to 75 in Germany; and mean baseline eGFR (ml/min/1.73m²), from 27 in Germany to 33 in France. Prevalence of diabetes ranged from 20% in France to 36% in Brazil, and that of stage A3 albuminuria (&gt;300 mg/g), from 31% in Brazil to 44% in the US. Mean systolic BP (mm Hg) ranged from 132 in Brazil to 143 in France, and the percentage of patients prescribed RAAS inhibitor, from 58% in the US to 81% in Germany. After median follow-up of 4.0 (2.6-5.0) years, 1897 participants progressed to kidney failure and 522 died before meeting this outcome. Two-year crude cumulative incidence of kidney failure was the lowest in France (14%), where patients were recruited at an earlier CKD stage, and similar across Germany (25%), the US (26%), and Brazil (27%); that for all-cause death, the lowest in Brazil (2.5%), followed by France (3.4%), the US (4.4%), and Germany (4.6%). Sequential adjustment for demographics and progression risk factors, in particular baseline eGFR and albuminuria, significantly reduced the gap between France and the other countries (Figure). Despite the associations of systolic BP (cs-HR 1.14, 95%CI 0.95-1.38 for 120-129; 1.18, 95%CI 0.95-1.46 for 130-139; and 1.46, 95%CI 1.23-1.74 for ≥140 versus &lt;120 mm Hg) and RAAS inhibitor prescription (cs-HR 0.81, 95%CI 0.70-0.95 at 6 months of follow-up) with kidney failure, adjustment for these two treatment targets only marginally changed comparisons across studied countries.

Conclusion

In CKD patients under nephrology care, BP control and RAAS inhibitor prescription were associated with lower risk of kidney failure and substantially varied across countries. Despite this variation in practice, BP control and RAAS inhibitor prescription appear to explain little of the differences in risk of kidney failure by country.

The tibial cut in total knee arthroplasty influences the varus alignment, the femoral roll-back and the tibiofemoral rotation in patients with constitutional varus

PURPOSE

Different alignment types for a better outcome after TKA were described. However, it is not clear how kinematic alignment influences knee joint kinematic. The purpose of this study was to analyze whether adapted tibial cuts in constitutional varus knees affect knee joint kinematics regarding femoral roll-back, varus/valgus angle, and femorotibial rotation.

METHODS

Seven cadaveric knees with constitutional varus alignment were examined in the native state and after implantation of a cruciate retaining (CR)-TKA with 0°, 3° and 6° tibia cuts using an established knee joint simulator. The effects of varus alignment on femorotibial rollback and rotation was determined. In addition, the native knee joint and different tibial cuts in CR-TKA were compared with Student's t test.

RESULTS

Total knee replacement with a 3° and 6° varus tibia cut had the greatest varus deviation to the native knee (mean 1.6° ± 0.09°, respectively); while, knees with a 0° (mean 0.2° ± 0.01°) tibia cut were most similar to the constitutional varus knee joint. The femoral roll-back in the medial compartment was increased in the native knee (5.7-12.5 mm). A 6° varus cut had a restricted translation in the medial compartment (2-3.2 mm). In the lateral compartment, the extensive translation was observed with a 0° varus cut, followed by 3° and 6° and the native knee. All cuts showed significantly different mean values. Only the cuts at 3° and at 6° in the medial compartment and the cuts at 0° and at 3° in the lateral compartment did not differ significantly. In respect to tibiofemoral rotation, 0° and 3° varus cuts across all loads had the least difference to the native knee (3.4°), with a 0° varus cut showing a higher absolute internal rotation of the tibia than the native knee. Changes in knee kinematics of the tibiofemoral rotation showed significantly different mean values.

CONCLUSION

The potentially improved outcome parameters in TKA with adapted tibia cuts in constitutional varus knees cannot be completely explained by the changes to knee kinematics. Mechanical alignment seems to result in more balanced load distribution and kinematics more closely resembling the native knee. From a kinematic point of view, it is not recommended to place the tibia in more than 3° of varus.

LEVEL OF EVIDENCE

Biomechanical study.

Degeneration alters the biomechanical properties and structural composition of lateral human menisci

OBJECTIVE

Because the literature relating to the influence of degeneration on the viscoelasticity and tissue composition of human lateral menisci remains contradictory or completely lacking, the aim of this study was to fill these gaps by comprehensively characterising the biomechanical properties of menisci with regard to the degree of degeneration.

DESIGN

Meniscal tissue from 24 patients undergoing a total knee replacement was collected and the degeneration of each region classified according to Pauli et al. For biomechanical characterisation, compression and tensile tests were performed. Additionally, the water content was determined and infrared (IR) spectroscopy was applied to detect changes in the structural composition, particularly of the proteoglycan and collagen content.

RESULTS

With an increasing degree of degeneration, a significant decrease of the equilibrium modulus was detected, while simultaneously the water content and the hydraulic permeability significantly increased. However, the tensile modulus displayed a tendency to decrease with increasing degeneration, which might be due to the significantly decreasing amount of collagen content identified by the IR measurements.

CONCLUSION

The findings of the current study may contribute to the understanding of meniscus degeneration, showing that degenerative processes appear to mainly worsen viscoelastic properties of the inner circumference by disrupting the collagen integrity.

The tibial cut influences the patellofemoral knee kinematics and pressure distribution in total knee arthroplasty with constitutional varus alignment

PURPOSE

The current literature suggests that kinematic total knee arthroplasty (kTKA) may be associated with better outcome scores in patients with constitutional varus alignment. The underlying patellofemoral kinematic changes (patella tilting and patella tracking) and patellofemoral pressure distribution have not yet been described. The present study compared the effects of different tibial cuts, as used in kTKA, on patellofemoral knee kinematics and the pressure distribution, in addition to comparisons with the natural constitutional varus knee.

METHODS

Seven cadaveric knee joints with constitutional varus alignment were examined in the native state and after 0°, 3°, or 6° tibial cut cruciate-retaining (CR)-TKA using an established knee joint simulator. The effects on patella rotation/patella tilting, patellofemoral pressure, and patellofemoral length ratios (= patella tracking) were determined. In addition, the natural knee joint and different tibial cuts in CR-TKA were compared (Student's t test).

RESULTS

In the patellofemoral joint, 6° CR-TKA was associated with the greatest similarity with the natural constitutional varus knee. By contrast, knees subjected to 0° CR-TKA exhibited the largest deviations of patellar kinematics. The smallest difference compared with the natural knee joint concerning patella tilting was found for 6° CR-TKA (mean 0.4°, p < 0.001), and the largest difference was noted for 0° CR-TKA (mean 1.7°, p < 0.001). Concerning patellofemoral pressure, 6° CR-TKA resulted in outcomes most similar to the natural knee joint, featuring a mean difference of 3 MPa. The largest difference from the natural knee joint was identified for 0° CR-TKA, with an average difference of 8.1 MPa (p < 0.001; total mean 17.7 MPa). Meanwhile, 3° and 6° CR-TKA induced medialization of the patella, with the latter inducing the largest medialization value of 4.5 mm at 90° flexion.

CONCLUSIONS

The improved outcome parameters in kTKA described in the literature could be attributable to the similar kinematics of the patellofemoral joint relative to the normal state. The current study confirmed the similar kinematics between the native constitutional varus knee joint and knee joints subjected to 3° or 6° CR-TKA (patellofemoral rotation/patella tilting and patella pressure). Conversely, there was pronounced medialization of the patella following 6° CR-TKA. Patella pressure and patella tilting are described in the literature as possible causes of anterior knee pain after TKA, whereas medialization of the patella, which is also influenced by other causes, might play a subordinate role.

LEVEL OF EVIDENCE

V, Biomechanical study.

SO053A REAL WORLD LONGITUDINAL ANALYSIS OF ANAEMIA TREATMENT PRESCRIPTIONS IN NON-DIALYSIS-DEPENDENT CHRONIC KIDNEY DISEASE PATIENTS, A CKDOPPS STUDY

Background and Aims

Previously lacking in the literature, this analysis aims to comprehensively describe longitudinal patterns of anaemia management, including prescriptions of ESA and iron replacement, for non-dialysis dependent chronic kidney disease (NDD-CKD) stage 3 to 5 patients under nephrologist care.

Method

We analysed data from a prospective cohort of 2455 NDD-CKD patients from Brazil, Germany and the US, who were not using anaemia medications (oral iron, intravenous [IV] iron, or erythropoiesis stimulating agent [ESA]) at enrolment in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDOPPS). We excluded 26% (N=862) of patients who were using any anaemia treatment from the source population at CKDOPPS study entry; we further excluded patients with (a) missing data for demographics and/or clinical history, or (b) no laboratory and medication data during follow-up. We reported the cumulative incidence (CI) of anaemia treatment initiation, stratified by biochemical parameters and patient characteristics. For patients that started therapy, we report the frequency of medication type at the moment of initiation, as well as switches and discontinuation over 12 months.

Results

The CI of any anaemia treatment initiation at 12 months was 18% for the whole sample, and 54% for patients with haemoglobin (Hb) &lt;10 g/dL. For oral iron therapy, the CI at 12 months was 26% (19%, 32%) for TSAT&lt;20%, and 22% (17%, 28%) for ferritin &lt;100. For IV iron use, CI at 12 months was 6% (3%, 11%) for patients with TSAT&lt;20% and 4% (2%, 7%) for patients with ferritin &lt;100ng/mL. For ESA use, the CI at 12 months was 38% (29%, 47%) for patients with Hb &lt;10 g/dL, and 11% (8%, 14%) for Hb 10 to &lt;12 g/dL. Oral iron alone was the overwhelming first treatment option in the US (67%) and Brazil (56%); in Germany, a higher prevalence of ESAs (38%) and IV iron use (15%) was noted. Anaemia medication switches and discontinuation patterns, over 12 months, are outlined in the figure. The majority patients starting anaemia treatment were no longer on therapy one year later in Brazil (54%) and the US (51%); discontinuation of treatment was much lower in Germany (22%).

Conclusion

Anaemia treatment is initiated in a limited number of NDD-CKD patients with clinical signs that would indicate to do so, and many patients discontinue treatment, for reasons yet to be clarified. Although haemoglobin was the main factor associated with prescriptions, only about half of patients with Hb&lt;10g/dL received any anaemia medication during a year. Oral iron was the treatment option most often prescribed, however given to only a quarter of iron deficient patients. We noticed country differences in the patterns of anaemia prescription and treatment discontinuation, over time, that could be due to regional policy and physician-led CKD anaemia management inequalities. These results provide longitudinal data supporting the concept that anaemia is sub-optimally managed among patients with NDD CKD in the real-world setting.

MO017ANTITHROMBOTIC THERAPIES AND CLINICAL OUTCOME OF ATRIAL FIBRILLATION IN ADULT HD-PATIENTS: LARGE LONG-TERM COHORT STUDY ON GERMAN NETWORK DATA

Background and Aims

ESRD (end stage renal disease) patients on hemodialysis (HD) with persistent atrial fibrillation (AF) are at high risk for cardio-vascular events, severe bleeding and rapid vascular/valvular calcification. In such patients standard vitamin-K based oral anticoagulation (VK-OAC) is debated, since prospective OAC studies are missing and smaller short-term register data showed conflicting results. Our study evaluated risk-factors, use of anticoagulants and clinical long-term outcome in a large representative German HD-cohort.

Method

After informed consent, we analysed pseudonymized benchmarking data (2013-2018) of 16226 adult chronic HD patients treated in a German outpatient dialysis network (Verband Deutsche Nierenzentren, DN) based on quarterly electronically transmitted data. Diagnoses were coded by “International Classification of Diseases (ICD)” and drugs via “Anatomical Therapeutical Chemical (ATC)” codes.

Results

At baseline in 2013, 2812 (17%) HD-patients had AF as coded diagnosis. AF-prevalence increased significantly (p&lt;0.001) with age (&lt; 65 yrs: 7%; 65-&lt;75 yrs: 22% &gt;75 yrs: 34%) without gender differences. Baseline CHA2DS2-Vasc (4.0/1.5) and HAS-Bled (3.2/0.9) risk scores indicated high risk for embolism and bleeding. Median observation time was 2.1 yrs (Range: 0–6 yrs.). Apart from dialysis-related heparin-supply four main approaches were applied: No active therapy, standard VK-OAC+/- aspirin/clopidogrel (VK-OAC+/-Asp/Clop), heparin-based therapy (Heparin+/-Asp/Clop) or only anti-thrombocyte drugs (Asp/Clop).

Baseline risk scores were not related to any adverse events. Outcome data are shown in the Table: event rates were low (8.8%) and comparable for all anticoagulant therapies, especially for cerebral adverse events (3.8%, range 3.3-4.5%). Patients on any anti-thrombotic therapy had similar outcome rates as patients without anticoagulant therapy. The latter had fewer overall bleeding events (3.8% vs. 5.0%; NS).

Finally, overall actual 6-yr mortality rates were high (55.8%; median survival 4.4 yrs) and significantly (p&lt;0.001) lower for patients without anti-coagulant therapy (48.9%; median survival 6.0 yrs) than for patients on anti-coagulant therapy (59.5%; median survival 4.0 yrs) with highest mortality on VK-OAC based therapy (60.3%; p&lt;0.001).

Conclusion

De-novo cerebral event-rates were rather low (&lt;0.8%/yr) and similar for all anti-thrombotic therapies and even for patients with no active therapy, suggesting major beneficial impact of regular dialysis-related heparin-supply. Since actual 6-yr mortality was high and survival was significantly better in patients without anticoagulants than for VK-OAC or other active therapy, we need prospective studies comparing anticoagulants even with no drugs and/or new interventional approachs (i.e. left atrial appendage closure) to provide valid future guidelines.

Chronic kidney disease progression and mortality risk profiles in Germany: results from the Chronic Kidney Disease Outcomes and Practice Patterns Study

BACKGROUND

Chronic kidney disease (CKD) progression among German patients in a representative setting has not been described previously. The Verband Deutsche Nierenzentren and Chronic Kidney Disease Outcomes and Practice Patterns Study established a longitudinal observational cohort among German CKD patients to research variations in patient care and outcomes in real-world nephrology practices.

METHODS

A cohort of CKD Stages 3 (25%) and 4 (75%) patients was established from German nephrologist-run CKD clinics in 2013-16. Linear models were used to determine the estimated glomerular filtration rate (eGFR) slope during follow-up and Cox models were used to assess outcomes of end-stage kidney disease (ESKD) and death.

RESULTS

A total of 1834 patients (median age 75 years, 58% male, 42% diabetics, median baseline eGFR 25 mL/min/1.73 m2) were followed for a median of 29 months. More than 50% had slow or no decline and 17% declined ≥5 mL/min/1.73 m2/year. After 4.5 years, the incidence of ESKD was 8% and of deaths without ESKD 16% among patients with eGFR ≥30 mL/min/1.73 m2 and 37% and 19% for eGFR <30 mL/min/1.73 m2. Adjusted models showed higher risks of ESKD or death for patients with worse kidney function at baseline, male sex, diabetes and higher blood pressure; a higher risk of ESKD with higher albuminuria; and a higher risk of death with older age or cardiovascular comorbidity.

CONCLUSIONS

Routine nephrology care of patients in Germany comprises mostly elderly patients, many with slow CKD progression. Identification of risk factors for CKD progression and mortality may help guide resources by closer follow-up of high-risk patients.

Cartilage survival of the knee strongly depends on malalignment: a survival analysis from the Osteoarthritis Initiative (OAI)

PURPOSE

Progression of osteoarthritis over time is poorly understood. The aim of the current study was to establish a timeline of "cartilage survival rate" per subregion of the knee in relation to mechanical alignment of the lower extremity. The study hypothesized that there are differences in progression of osteoarthritis between varus, valgus and physiologic lower extremity alignment.

METHODS

Based on hip-knee-ankle standing radiographs at baseline, 234 knees had physiologic (180° ± 3°, mean 179.7°), 158 knees had varus (< 177°; mean 174.5°) and 66 knees valgus (> 183°; mean 185.2°) alignment (consecutive knees of the OAI "Index Knee" group, n = 458; mean age 61.7; 264 females). The Osteoarthritis Initiative (OAI; a multi-center, longitudinal, prospective observational study of knee osteoarthritis [30] using MRIs) defines progressive OA as a mean decrease of cartilage thickness of 136 µm/year and a mean decrease of cartilage volume by 5% over 1 year (DESS sequences, MRI). A Kaplan-Meier curve was generated for osteoarthritis progression based on OAI criteria.

RESULTS

Osteoarthritis progression based on volume decrease of 5% in varus knees occurred after 30.8 months (medial femoral condyle), after 37 months (medial tibia), after 42.9 months (lateral femoral condyle) and 43.4 months (lateral tibia), respectively. In a valgus alignment progression was detectable after 31.5 months (lateral tibia), after 36.2 months (lateral femoral condyle), after 40.4 months (medial femoral condyle) and 43.8 months (medial tibia), respectively. The physiological alignment shows a progression after 37.8 months (medial femoral condyle), after 41.6 months (lateral tibia), after 41.7 months (medial tibia) and after 43 months (lateral femoral condyle), respectively.

CONCLUSION

Based on data from the OAI, the rate and location (subregion) of osteoarthritis progression of the knee is strongly associated with lower extremity mechanical alignment.

LEVEL OF EVIDENCE

Level I (prognostic study).

International variation in the management of mineral bone disorder in patients with chronic kidney disease: Results from CKDopps

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is commonly associated with mineral and bone metabolism disorders, but these are less frequently studied in non-dialysis CKD patients than in dialysis patients. We examined and described international variation in mineral and bone disease (MBD) markers and their treatment and target levels in Stage 3-5 CKD patients.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Prospective cohort study of 7658 adult patients with eGFR <60mL/min/1.73m², excluding dialysis or transplant patients, participating in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) in Brazil, France, Germany, and the US. CKD-MBD laboratory markers included serum levels of phosphorus (P), calcium (Ca), intact parathyroid hormone (iPTH), and 25-hydroxyvitamin D (25-D). MBD treatment data included phosphate binders and vitamin D (nutritional and active). Nephrologist survey data were collected on target MBD marker levels.

RESULTS

Over two-thirds of the patients had MBD markers measured at time intervals in line with practice guidelines. P and iPTH increased and Ca decreased gradually from eGFR 60-20mL/min/1.73m² and more sharply for eGFR<20. 25-D showed no relation to eGFR. Nephrologist survey data indicated marked variation in upper target P and iPTH levels. Among patients with P>5.5mg/dL, phosphate binder use was 14% to 43% across the four countries. Among patients with PTH >300pg/mL, use of active (calcitriol and related analogs) vitamin D was 12%-51%, and use of any (active or nutritional) vitamin D was 60%-87%.

CONCLUSIONS

Although monitoring of CKD-MBD laboratory markers by nephrologists in CKDopps countries is consistent with guidelines, target levels vary notably and prescription of medications to treat abnormalities in these laboratory markers is generally low in these cross-sectional analyses. While there are opportunities to increase treatment of hyperphosphatemia, hyperparathyroidism, and vitamin D deficiency in advanced CKD, the effect on longer-term complications of these conditions requires study.

Anemia and iron deficiency among chronic kidney disease Stages 3-5ND patients in the Chronic Kidney Disease Outcomes and Practice Patterns Study: often unmeasured, variably treated

Background

International variation in anemia assessment and management practices in chronic kidney disease (CKD) is poorly understood.

Methods

We performed a cross-sectional analysis of anemia laboratory monitoring, prevalence and management in the prospective Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps). A total of 6766 participants with CKD Stages 3a–5ND from nephrology clinics in Brazil, France, Germany and the USA were included.

Results

Among patients with anemia (hemoglobin <12 g/dL), 36–58% in Brazil, the USA and Germany had repeat hemoglobin measured and 40–61% had iron indices measured within 3 months of the index hemoglobin measurement. Anemia was more common in the USA and Brazil than in France and Germany across CKD stages. Higher ferritin and lower iron saturation (TSAT) levels were observed with lower hemoglobin levels, and higher ferritin with more advanced CKD. The proportion of anemic patients with ferritin <100 ng/mL or TSAT <20% ranged from 42% in Brazil to 53% in France and Germany, and of these patients, over 40% in Brazil, Germany and the USA, compared with 27% in France, were treated with oral or intravenous iron within 3 months after hemoglobin measurement. The proportion of patients with hemoglobin <10 g/dL treated with erythropoiesis-stimulating agents ranged from 28% in the USA to 57% in Germany.

Conclusions

Hemoglobin and iron stores are measured less frequently than per guidelines. Among all regions, there was a substantial proportion of anemic patients with iron deficiency who were not treated with iron, highlighting an area for practice improvement in CKD care.