Chronic Kidney Disease Stage 3a Research Articles

#2514 Clinical impact of the CKD-EPI 2021 versus the CKD-EPI 2012 formula on GFR estimation and CKD prevalence: results from a Dutch routine-care cohort

Abstract Background and Aims Quantifying the kidney function is crucial for diagnosing and monitoring kidney disorders in clinical practice. Recently, the CKD-EPI 2021 formula was developed for estimating glomerular filtration rate (eGFR), excluding the ethnicity variable. In this study, we aimed to analyze the impact in a Dutch routine-care cohort of introducing the new serum creatinine-based CKD-EPI 2021 formula on glomerular kidney function estimation and the prevalence of chronic kidney disease (CKD), compared to the now used CKD-EPI 2012 formula. Method All patients of 18 years and older of whom serum creatinine was measured between January 2013 and December 2023 at the University Medical Center Utrecht in the Netherlands, were included. Differences in the eGFR measured with the CKD-EPI 2012 formula and the new CKD-EPI 2021 formula were defined as median difference, stratified by gender, age categories, and CKD stages. Results 251.960 patients with 2.312.313 serum creatinine measurements were included in our analysis. Our findings indicate that the CKD-EPI 2021 formula results in a higher eGFR compared to the CKD-EPI 2012 formula (median +3.6 (Inter quartile range (IQR) 2.4 to 4.5) ml/min/1.73 m2 in men, and median +3.1 (IQR 2.0 to 4.0) ml/min/1.73 m2 in women). In total, 21.1% of the patients with CKD stage 2-5 according to the CKD-EPI 2012 formula were classified as having a better CKD stage using the new CKD-EPI 2021 formula; 26.1%, 20.5%, and 15.1% of the patients classified as having CKD stage 3A, 3B, and 4 were classified as having CKD stage 2, 3A, and 3B, respectively (Table 1). Conclusion The introduction of the CKD-EPI 2021 formula would have significant implications for kidney function estimation in the Dutch clinical setting. It is crucial to consider these differences when interpreting kidney function data and making clinical decisions, especially given the potential impact on diagnosing CKD and dosing medication.

#853 Kidney-protective medication and risk of adverse clinical outcomes in patients with chronic kidney disease: preliminary findings from DISCOVER CKD

Abstract Background and Aims Renin-angiotensin-system inhibitors (RASi) have been a foundational therapy in chronic kidney disease (CKD) for several decades. Sodium-glucose co-transporter-2 inhibitors (SGLT2i) have also emerged as a critical disease-modifying therapy in CKD, with contemporary data from trials showing SGLT2i to significantly improve kidney and cardiovascular (CV) outcomes in patients with or without diabetes. Nonetheless, several studies have revealed sub-optimal prescribing of RASi and/or SGLT2i therapy (both herein referred to as kidney-protective medication) in patients with CKD. Using prospective data from the DISCOVER CKD study, we conducted an exploratory analysis to assess the association of kidney-protective medication real-world use with mortality risk, CV events (fatal and non-fatal), and hospitalisation in patients with CKD. Method DISCOVER CKD (NCT04034992) is a multi-country, non-interventional cohort study designed to characterise the epidemiology of CKD, including describing patient characteristics, disease progression, clinical outcomes, patient journey, practice patterns, and clinical management. In the prospective phase, patients with CKD were recruited from the UK, USA, Spain, Italy, Sweden and Japan between September 2019 and June 2022. Clinical data were extracted manually from patients’ health records into a standardised case report form. The current analysis includes 12 months’ follow-up data. A Cox proportional hazards model was used to compare the risk of all-cause mortality and CV events and a negative binomial regression model was used to compare the risk of all-cause hospitalisation between patients receiving and not receiving kidney-protective medication at baseline, with adjustments for age, sex, CKD stage, diabetes mellitus, hyperkalaemia, and heart failure. DISCOVER CKD received research ethics board approval, and informed consent was obtained from all patients. Results Of the 1052 patients enrolled in DISCOVER CKD, 643 (61.1%) were receiving kidney-protective medication in the form of RASi (n = 618) and SGLT2i (n = 147) at baseline. The mean age of participants receiving and not receiving kidney-protective medication was 62.4 years and 62.7 years, respectively; 34.4% and 40.8%, respectively, were female. Most patients had CKD stage 3A (n = 332, 31.6%) or 3B (n = 308, 29.3%), and 8.4% (n = 88) had ongoing dialysis. Body mass index (30.4 vs 29.4 kg/m2) and blood pressure were similar for those receiving kidney-protective medication versus those who were not. Laboratory assessments were also generally similar, although estimated glomerular filtration rate (eGFR; 40.9 vs 33.7 mL/min/1.73 m2) and haemoglobin (132.0 g/L vs 124.0 g/L) were higher in patients receiving kidney-protective medication versus those not. During the follow-up, patients receiving kidney-protective medication had a 67% lower risk of all-cause mortality (hazard ratio [HR] 0.33; 95% confidence interval [CI] 0.12–0.80, p = 0.019), and a 20% lower risk of all-cause hospitalisation (HR, 0.80; 95% CI 0.64–0.99, p = 0.042) compared with patients not receiving kidney-protective medication. In the population without pre-existing CV disease, a trend towards a lower rate of CV events was observed in patients with kidney-protective medication (CV events rates: 2.2 vs 3.2 per 100 person-years; HR, 0.38; 95% CI 0.12–1.08, p = 0.074 (Figure). Conclusion In this multinational CKD cohort, preliminary analysis indicates that using kidney-protective medication was associated with lower risks of adverse outcomes including death. Further analysis to mitigate potential confounding will be performed to confirm these preliminary findings.

#1993 Analysis of the characteristics of IgA nephropathy patients using real-world data from five European countries

Abstract Background and Aims Immunoglobulin A nephropathy (IgAN) is the most prevalent primary glomerulonephritis globally; it has a significant health burden and a highly variable disease course. As IgAN is a heterogeneous disease, it is important to appreciate the associated patient characteristics in order to understand disease progression and how best to implement individualised treatment regimens. To determine the patient characteristics associated with IgAN, a physician questionnaire and patient chart audit were conducted. Method From 21 December 2022 to 6 February 2023, physicians from five European countries (France, Germany, Spain, Italy and the UK) completed a questionnaire and patient chart review of their IgAN patients. Physicians were required to have ≥50 patients with stage 1–4 chronic kidney disease (CKD); at least four of these were required to be non-dialysis IgAN patients. Patients whose charts were included were required to be aged 12 years or older, non-dialysis IgAN patients and have an estimated glomerular filtration rate of ≥15 mL/min/1.72 m2. The charts included were required to be from patients who had seen a participating physician within the prior 6 months. Results 261 physicians answered the questionnaire and completed chart audits on 473 of their most recently seen patients. Patient charts audited were largely from male (71%) Caucasian (78%) patients from 31–49 years of age (38%). 22% of patients were referred to their current physician within the past year. Most patients (70%) were referred by a primary care physician and 9% by another nephrologist. Of those referred by a nephrologist, 32% were referred for specialised care. Participating physicians perceived that close to 30% of patients were referred to them late or extremely late, with contributing factors including lack of engagement from patients with annual follow-ups and patients remaining asymptomatic for a long time. At the most recent visit, 24.3% had CKD stage 1 or 2, 26.6% of patients had CKD stage 3a, 30.4% had stage 3b and 18.6% had stage 4 disease. Nephrologists characterised 53% of their CKD stage 4 patients as having severe IgAN. The symptoms reported with greatest frequency at the most recent visit included fatigue (59%), blood in the urine (41%) and increased weight gain (41%). In total, 71% of patients had proteinuria >0.5 g/day (8% had no values available) and 8% of patients had nephrotic syndrome (urine protein >3.5 g/day and low serum albumin). In total, 28% of patients had no co-morbid conditions. More than half (54%) of the patients whose charts were audited had comorbid hypertension. Other comorbidities included hyperlipidaemia (22%), obesity (17%), type 2 diabetes (15%) and peripheral oedema (7%). Counterintuitively, when asked about the overall health of their patients, physicians perceived the majority (98%) of patients to be in good or excellent overall health. Patients were prescribed five medications on average, with most (92%) taking an angiotensin converting enzyme inhibitor or angiotensin receptor blocker, or both. The number of medications prescribed increased after the age of 50. Two-thirds (66%) of physicians felt that patients completely adhered to their treatment regimen. However, 54% of physicians reported some form of dissatisfaction with the response of their patients to their overall treatment regimen; though, levels of satisfaction varied between individual treatment options. Conclusion Despite high rates of proteinuria and patients often in late-stage CKD at referral, physicians perceived the majority of patients to be in good or excellent overall health, revealing a potential gap in physicians’ perceptions of patients’ health and their risk of progression to kidney failure. As a result, patients were often diagnosed or referred late and their perception of their own health may have led to a lack of engagement with physicians. These data indicate that there is an unmet need for early diagnosis and treatment of IgAN to ensure that patients receive appropriate care.

#837 Information needs and emotional impact when receiving a diagnosis of chronic kidney disease: insights from DISCOVER CKD

Abstract Background and Aims Chronic kidney disease (CKD) is often a silent condition, with symptoms typically not appearing until a large proportion of kidney function has been lost. Therapeutic interventions, e.g., disease-modifying medications, blood pressure and diabetes control, and lifestyle changes, can delay CKD progression, particularly if instigated early. However, psychological distress can reduce adherence to interventions. It is important patients are adequately informed about their diagnosis to improve adherence and reduce the impact of distress. Multinational, real-world data on patient experiences with CKD, particularly about clinical management, treatment patterns and quality of life, are limited. This DISCOVER CKD sub-study aimed to capture the emotions elicited by patients at CKD diagnosis and their perceptions of the information received. Method DISCOVER CKD (NCT04034992) is a multinational cohort study that aims tocharacterise the epidemiology of CKD and describe patient characteristics, CKD progression, clinical outcomes, the patient journey, practice patterns, and clinical management. The current analysis includes a subset of patients from the USA, UK, Japan, and Spain, who participated in 1-2-1 telephone interviews about their CKD experience, including their disease journey and interactions with the healthcare system. Interview topics in DISCOVER CKD were informed by a pilot study that utilised data from PatientsLikeMe, an online network for patients to share personal stories and health data. Qualitative interviews, conducted in the local language by trained interviewers, January–June 2023, lasted ∼60–90 minutes. Transcribed interviews were translated into English for coding (MAXQDA Plus 2022 v22.3.0) and analysis. The study received research ethics board approval and all participants provided written informed consent. Results 103 patients (mean age 63.1 years; 42.7% female; 51.5% with type 2 diabetes) were interviewed. Most had CKD stage 3A (22.3%) or 3B (28.2%); 26.2% had stage 4 or 5 no dialysis and 9.7% were stage 4 (n = 1) or 5 on dialysis. Average time since diagnosis was 9.5 years. Over one-third (38.8%; n = 40/103) of participants did not recall any specific symptoms or signs of CKD prior to diagnosis. Of the pre-diagnosis symptoms reported, the most common was fatigue (21.4%; n = 22/103), then high blood pressure (15.5%; n = 16/103) and swelling (11.7%; n = 12/103). With respect to patient experiences, 55.2% (n = 32/58) said they did not feel sufficient information about CKD was provided at diagnosis and 59.2% (n = 45/76) said no information about their CKD stage was shared. Participants felt overwhelmed and confused about the diagnostic process and struggled to understand the information provided to them, including information about kidney function and symptoms. To supplement their understanding, participants reported using additional sources of information, including the internet (52.9%; n = 36/68), other healthcare professionals (HCPs) (19.1%; n = 13/68), books/printed information (11.8%; n = 8/68) and patient support groups (8.8%; n = 6/68). The most common emotions experienced at the time of diagnosis were worry and fear (28.2%; n = 29/103), then shock/surprise (25.2%; n = 26/103) (Figure). For those reporting no reaction (27.2%; n = 28/103), many stated the condition had no discernible effect on their daily lives. Reasons for fear or worry were related to the potential for disease progression. Conclusion Many patients expressed dissatisfaction with the information they received at their CKD diagnosis. This suggests that HCPs could dedicate more time to explaining the diagnosis, the characteristics and severity of CKD, likelihood of progression, and the benefits of self-management and adherence to intervention. This could be particularly important for those without symptoms at the time of diagnosis, and patients who rely on HCPs as their primary source of information. Patients should be asked what information they want to receive and be directed to trusted sources. The diagnostic process was a highly emotional experience for many patients and counselling or psychological therapy should be considered.

#181 Dysbiosis of gut microbiota in patients with chronic kidney disease

Abstract Background and Aims The human intestinal tract contains 100 trillion microorganisms, and 500–1000 microbial strains exist in each individual, classified into two main phyla: Firmicutes and Bacteroidetes. The gut bacterial microbiota is altered in patients with chronic kidney disease (CKD). However, the bacterial composition at each stage of CKD is unclear in these patients, including those receiving renal replacement therapy. In this report, we present the changes in the gut microbiota among patients with CKD. Method A total of 93 individuals were recruited for the study. Seventy-three patients had stage 3–5 CKD, including those receiving renal replacement therapy (CKD group), and 20 were age- and sex-matched controls (CKD stage 1–2). Gut microbiome composition was analyzed using a 16S ribosomal RNA gene-based sequencing protocol. Results The beta diversity of the samples was evaluated via principal coordinates analysis (PCoA). The unweighted and weighted UniFrac distances revealed a tendency toward separation of microbiota in the samples according to the CKD stage 1–2 and CKD stage 3–5, 5D groups. At the genus level, the butyrate-producing bacteria Lachnospira, Blautia, Coprococcus, Anaerostipes, and Roseburia were more abundant in the control group (Linear Discriminant Analysis score of >3) than in the CKD group. Lachnospira was more abundant in the control group than in patients with CKD stage 3a. Compared to the control group, multiplex butyrate-producing bacteria were deficient in patients with CKD stage 3b–5D, including in patients receiving renal replacement therapy. Conclusion Our findings highlight that the gut bacterial composition, including butyrate-producing bacteria, deteriorates from CKD stage 3b. Even after renal replacement therapy, the bacterial composition did not change.

#2130 Pregnancy in patients with chronic kidney disease stage 3 to 5: what to expect?

Abstract Background and Aims Chronic Kidney disease (CKD) has long been recognized as a risk factor for adverse pregnancy outcomes. Advanced CKD is also associated with decrease fertility, raising the importance of an early approach of pre- menopausal CKD women to discuss pregnancy planning and avoid long term kidney function deterioration or prematurity sequelae in their child-to-be. Method Retrospective analysis of maternal, obstetric and perinatal outcomes of patients with CKD stage 3 to 5, followed by the Nephro-obstetric clinical team between 2011 until 2023. Results We evaluated 31 gestations in 28 patients, with mean age of 32 years [19-43], 21 Caucasian and 7 African, 15 nulliparous, 21/28 with hypertension (HTN), 6/28 diabetic, 2/28 with HIV and 3/28 with systemic lupus erythematosus (SLE). CKD diagnosis occurred during pregnancy in 4/28 patients. Mean pre-pregnancy SCr was 2,1 ± 1 mg/dL [1,1-4,3] and mean proteinuria was 1535 ± 1874 mg/day [5 - 6000], and 11 patients had proteinuria >1 g/day. At gestation baseline, patients evaluated in each pregnancy were in CKD stage 3a (9/31), 3b (10/31), 4 (8/31) and 5 (4/31). CKD etiologies were heterogenous, with most common diagnosis being hereditary nephropathies (7/28), Diabetic nephropathy (6/28) and lupus nephritis (3/28). Exposure to teratogenic therapy occurred in 10/31 gestations (mean time of 11 weeks; 2 - 15), generally ACE/ARBs. Medical termination of pregnancy occurred in 3 gestations due to active SLE and severe growth restriction, 1 abortion at 16 weeks and 1 stillbirth due to cervical insufficiency. HTN aggravation occurred in 16/31 (52%) gestations and de novo proteinuria or proteinuria increase occurred in 7/31(22,5%) and 20/31 (64.5%) gestations, respectively due to pregnancy hyperfiltration, active lupus nephritis and preeclampsia. Considering pregnancies that progressed, renal function (RF) deterioration occurred 10/19 (53%) patients in CKD stage 3 with 20%/60%/20% with full/partial and no RF recovery, respectively. In CKD4 6/7 patients (86%) had RF aggravation with 17% and 83% with partial or no RF recovery. Of the 2 Patients in CKD stage 5 with gestation >20 weeks, 1 started dialysis during pregnancy and the other 4 months postpartum. Dialysis was initiated in 3 patients during pregnancy (2 CKD stage 4 and 1 CKD stage 5) due to urea level >100 mg/dL. RF deterioration was mainly due to pregnancy hyperfiltration and preeclampsia (11/26 gestations; 42%). Mean gestation age at delivery was 34 ± 4 weeks (28-41), with 73% and 53,8% pregnancies with gestational age <37 and 34 weeks, respectively. Mean birth weight was 1866 ± 707 g (555–3095 g), with 73% low birth weight (<2500 g). Mean Apgar 1/5/10 was 9/10/10, respectively. Cesarean was performed in 53,8% gestations and 61,5% newborns were admitted to the neonate care unit (NICU) due to prematurity Conclusion CKD patients with stage 3 to 5 are at increased risk of worse maternal outcomes, namely HTN aggravation (52%), de novo or increase proteinuria (87%) and RF deterioration (53% stage 3 and 86% stage 4) with significant permanent loss of kidney function. Obstetric and perinatal results were also significantly worse with a high incidence of preeclampsia (42%), prematurity (73%), low birth weight (73%) and the need of NICU (61.5%). It is of sum importance, that advanced CKD patients are previously counseled about those risks and are managed in a multidisciplinary feto- maternal clinic experienced in CKD pregnancy care that has a dialysis unit.

#2099 Long term outcomes in chronic kidney disease patients with heart failure with preserved ejection fraction

Abstract Background and Aims Heart failure (HF) is frequent in chronic kidney disease (CKD) and leads to high morbidity and mortality in this patient category. The aim of our study is to assess the clinical and biological profile, and outcomes in CKD patients with preserved left ventricular ejection fraction (LVEF). Method We prospectively enrolled CKD patients (pts) in pre-dialysis, stratified in two groups by the presence of heart failure symptoms: pts with NYHA class 1-2 (asymptomatic HF) versus pts with NYHA class 3-4 (symptomatic HF). Demographics, clinical history, co-morbidities, physical exam, ambulatory blood pressure monitoring, extensive blood chemistry, systemic inflammation and mineral bone disease parameters were recorded. Cardiac structure and systolic and diastolic function were assessed by echocardiography. Carotid Doppler ultrasound assessed intima media thickness (IMT). Al patients were followed until death of loss from records; patients with less than 6 months of surveillance were excluded. Primary endpoint was all-cause mortality. Secondary endpoints were cardiovascular mortality, a composite cardiac endpoint composite cardiac endpoint comprising coronary heart disease, heart failure hospitalization and new-onset arrhythmia, and reaching the end stage of renal disease (ESRD). Results We included 76 CKD patients (2 pts CKD stage 1, 9 pts CKD stage 2, 19 pts CKD stage 3a, 28 pts CKD stage 3b, 18 pts CKD stage 4) with LVEF ≥ 50%. Mean age 64.7 ± 11.4 years (yrs), men = 56 (73.7%). Mean follow up period was 86 ± 46.4 months (range 6-156 months). Patients with symptomatic HF (54 pts, 71.1%) were older (68 ± 9 vs 56 ± 12 yrs), hypertensive (98.1% vs 86.4%, p < 0.05), more frequent coronary artery disease (66.7% vs 27.3%, p < 0.05), had worse baseline biological profile: lower eGFR (36.9 ± 12.9 vs 55.5 ± 22.7 ml/min/1.73 m2, p < 0.05), lower serum albumin (4.1 ± 0.5 vs 4.4 ± 0.4 g/dl, p < 0.05), as well as higher levels of osteoprotegerin and fetuin A (p < 0.05). Also, symptomatic HF pts had more severe endothelial disease (higher IMT 0.81 ± 0.14 vs 0.63 ± 0.11 mm, p < 0.05), more severe subclinical LV dysfunction revealed by less negative global longitudinal strain GLS (−16.7 ± 2.66 vs −19.2 ± 2.95, p < 0.05) and higher ratio of mitral velocity to early diastolic velocity of the mitral annulus E/E` (12.64 ± 3.63 vs 9.68 ± 2.73, p < 0.05), as well as higher LV mass index (121.5 ± 31 vs 104.9 ± 22.7 g/m2, p < 0.05) and higher left atrial volume index LAVI (42.8 ± 16.8 vs 31.8 ± 11.3 ml/m2, p < 0.05) All-cause mortality was 17.1% (13 events), while cardiovascular mortality was 6.6% (5 events). All deaths were recorded in the symptomatic HF group. Also, a higher percent of pts from symptomatic HF group reached the composite cardiac endpoint (44.4% vs 22.7%) and ESRD (33.3% vs 18.2%) compared to asymptomatic HF group. Kaplan-Meier survival analysis showed significantly higher all-cause mortality (log rang = 0.008) and lower ESRD-free survival (log rank= 0.045) in symptomatic HF group. All-cause mortality was significantly correlated with NYHA class (p < 0.0001), etiology of CKD (p = 0.038), eGFR (p < 0.0001), proteinuria (p = 0.001), intact PTH (p = 0.008), osteocalcin (p = 0.012), osteopontin (p = 0.029), FGF23 (p = 0.044), IL6 (p = 0.037), GLS (p = 0.023), E/E` (p = 0.009). Cardiovascular mortality was significantly correlated with NYHA class (p = 0.019), etiology of CKD (p = 0.008), eGFR (p = 0.011), proteinuria (p = 0.001), intact PTH (p = 0.008), osteocalcin (p = 0.011), osteopontin (p = 0.006), FGF23 (p = 0.006). Cox regression analysis identified NYHA class (p = 0.004), FGF23 (p = 0.009) and IL6 (p = 0.025) as predictors for all-cause mortality, while E/E` (p = 0.032) and intact PTH (p-0.042) were predictors for cardiovascular mortality. Conclusion In our study, CKD pts with symptomatic HF carry a significant burden of morbidity and mortality, even in the case of preserved LV ejection fraction. This emphasizes the need for more comprehensive regular assessments of subclinical cardiac dysfunction in CKD pts. This approach might support targeted interventions, better symptom control, and improved long term outcomes.

#1241 Healthcare resource utilisation in adults with chronic kidney disease by KDIGO categorisation in England: 2010-2019

Abstract Background and Aims Chronic kidney disease (CKD) is associated with high clinical burden for patients and substantial economic costs for healthcare systems. Detailed estimates of healthcare resource utilization (HCRU) for patients with CKD in the UK are limited, particularly by stage of CKD. This study assessed outpatient and non-elective inpatient HCRU by stage of CKD in England. Method This non-interventional study utilised data from primary care electronic health records from Clinical Practice Research Datalink (CPRD) AURUM and Hospital Episode Statistics (HES) admitted patient care (APC). Patients aged ≥18 years registered in CPRD with eligible linkage to HES between January 1, 2010 and December 31, 2019 with 2+ eGFR measurement during the period were identified. CKD was defined by eGFR <60 ml/min/1.73 m2 and/or presence of a uACR measurement ≥3 mg/mmol, both confirmed by a second measurement 90-365 days later. Start of follow-up (index) was set to the earliest date during the study period that CKD was confirmed. Follow-up for HCRU ended at earliest of death, administrative censoring, or 31st December 2019. Patients with end-stage kidney disease (eGFR <9 ml/min/1.73 m2) at index were excluded. Number of HCRU events for each HCRU category was estimated as rates per 1,000 person years (PY) for each calendar year based on cumulative number of events. Event rates were calculated as number of outcomes/total time at risk. Confidence intervals (95%) were calculated assuming a Poisson distribution. Age- and sex-adjusted rates were calculated to compare rates across CKD stages. Results Of 6.1 million adult patients meeting study inclusion criteria, 743,945 adults (12.2%) with CKD were identified. Mean age (SD) was 76.1 (11.5) years, 55.2% were female, and 89.8% White, contributing a total of 3,055,600 years of follow-up. Most (60.9%) patients had stage 3a CKD (eGFR 45-<59 ml/min/1.73 m2). Among patients with uACR measurements (44.4%), 48.0% were A1 (<3 mg/mmol), 44.4% A2 (3-30 mg/mmol), and 7.6% A3 (>30 mg/mmol). Overall, per 1000 PY, there were 24,763 primary care visits, 475 non-elective all-cause hospitalisations, 4,950 attended (722 unattended) outpatient visits, including 308 (43 unattended) outpatient nephrology visits and 368.1 attended (61.2 unattended) cardiology visits. For all HCRU categories, greater KDIGO risk category at index was associated with higher HCRU. For example, after age and sex adjustment, patients with CKD stage 3b had a mean of 0.53/PY non-elective all-cause hospitalisations compared to 0.77/PY for patients with CKD stage 4. Additionally, a mean of 5.18 outpatient visits per PY was observed for patients with CKD stage 3b, of which 0.91 were nephrology outpatient visits compared to 8.39 outpatient visits per PY for stage 4, of which 2.65 were nephrology outpatient visits. Generally, both lower eGFR and higher uACR were individually associated with higher HCRU. Conclusion This study demonstrates high HCRU for patients with CKD, with increasing rates of HCRU with lower kidney function and greater kidney damage. Patients with more advanced CKD contribute at a disproportionally higher rate of outpatient healthcare encounters and non-elective hospitalisations. Efforts to prevent the development and progression of CKD and improving clinical outcomes will reduce frequency and cost of HCRU.

#1244 Rates of eGFR and UACR testing in patients with chronic kidney disease in England: Clinical Practice Research Datalink 2010-2019

Abstract Background and Aims The NICE chronic kidney disease (CKD) treatment guidelines recommend regular laboratory measurements of both kidney function (eGFR) and damage (proteinuria) to appropriately inform efforts to prevent and treat progression of CKD. Recommendations also indicate frequency of such testing should increase with CKD progression. There are few data on rates of testing in patients with confirmed CKD with particularly paucity in patients with various stages of CKD. Method This non-interventional, observational study utilised data from primary care electronic health records from Clinical Practice Research Datalink (CPRD) AURUM. Patients aged ≥18 years with CKD registered in CPRD with at least one year of follow-up (FU) between January 1, 2010 and December 31, 2019 were identified. CKD was defined by an eGFR <60 ml/min/1.73 m2 and/or presence of a uACR measurement ≥3 mg/mmol, both confirmed by a second measurement 90-365 days later (index). Patients with eGFR <9 ml/min/1.73 m2 at index were excluded. Frequency of renal testing (eGFR and UACR) for each complete year of FU was quantified starting the day after index and patients were censored the last day of the final complete calendar year of FU after index. Frequency of renal testing per FU year was calculated overall and by CKD stage and level of albuminuria at index. Results In the 650 565 patients with CKD identified, mean age (SD) was 76.1 (11.3) years, 55.4% were female, and 88.5% White. Most (62.0%) patients had stage 3a CKD (eGFR 45-<59 ml/min/1.73 m2) at index. Among patients with UACR measurements within 1 year prior to index (54.1%), 49.3% were A1 (<3 mg/mmol), 43.4% A2 (3-30 mg/mmol) and 7.3% A3 (>30 mg/mmol) at index. During the first year of FU, 81.45% of patients had 1+ eGFR test whereas 39.2% had 1+ UACR test. Patients more frequently received 1+ eGFR per year over subsequent years of FU but the low proportion with 1+ UACR test per year remained stable for UACR. The mean (SD) number of eGFR and UACR tests performed per patient in the first year of FU was 2.09 (2.39) and 0.49 (0.70), respectively. More frequent eGFR testing was observed with lower eGFR at index and across subsequent years of FU. Frequency of UACR testing was lower at more advanced stages of CKD at index in all FU years, however, no trends in UACR testing frequency were observed by level of albuminuria at index. Conclusion This evidence from a population-based sample of patients with confirmed CKD in England, indicates that eGFR is being monitored in the majority of patients, yet UACR testing is suboptimal according to NICE guidelines regardless of level of kidney function or level of albuminuria. Although eGFR testing is more frequent at more advanced stages of CKD, UACR testing seems to become less frequent with more advanced stages of CKD. With emergence of new therapies to prevent progression of CKD, efforts to increase frequency of UACR testing are needed (particularly in earlier CKD stages) to ensure that patients who are at risk of worsening CKD and albuminuria receive appropriate management.

#511 Inadequate diagnostic investigations and low treatment rates in CKD anemia: an inertia that can only change with long-term follow-up

Abstract Background and Aims Anemia is observed from the early stages in the course of chronic kidney disease (CKD), and as the stage progresses, the severity of anemia and its impact on quality of life increase. Early diagnosis of anemia in chronic kidney disease, assessments related to its etiology, and treatment are therefore crucial. There is no comprehensive and long-term study in Turkey addressing the diagnostic and therapeutic management of anemia seen in the course of chronic kidney disease. The aim of this study is to investigate the frequency of anemia in different stages of CKD in patients diagnosed with Stage 3 and more advanced stages, to evaluate the effectiveness of diagnostic approaches, and management of iron parameters and anemia, and to investigate the effect of anemia on patient survival. We aim to present “real-life” data from this study to guide clinical practice and correct errors or deficiencies in anemia management. Method This study is a single-center, observational-descriptive retrospective study. 1321 outpatients with Stage 3A and advanced CKD and anemia who admitted to Hacettepe University Faculty of Medicine Nephrology Clinic between 2014 and 2018 were included in the study. Data for demographics, CKD etiologies and stages, anemia severities, comorbid diseases were collected from electronic health system (Table 1). Diagnostic investigations for anemia evaluation and therapeutic interventions such as administration of iron, folic acid, vitamin B12, erythropoiesis stimulating agents (ESA) were assessed. The long-term yield of diagnostic and therapeutic approaches and their effects on survival were also evaluated. The study investigated whether the severity of anemia and improvement in anemia had an effect on survival. Results Ferritin is the most commonly performed test for the etiology of anemia (76.4%). Request rates for tests such as B12, folic acid, transferrin saturation and reticulocyte are below 20%. More than half of the patients with anemia (59.4%) have not received any form of anemia treatment. Even among those whose ferritin test was checked and the value was <100 µg/dL, only 41.4% were given iron treatment. As the clinical follow-up period of the patients increased, it was observed that anemia treatment was applied better and target values were reached more frequently (p < 0.001). More than one third of the patients (34.8%) died during follow-up. The overall survival in patients whose anemia improved was 79.8%, and it was 62.8% in patients whose anemia did not improve the overall survival was (p = 0.002) (Fig. 1). When examining the relationship between survival status and anemia severity for the non-dialysis-dependent CKD Stage 3-5 group, there was a statistically significant survival difference between the Hb group of 10-11.9 g/dL to Hb group of <10 g/dL (p = 0.004). Conclusion This study has shown that diagnostic tests for etiology of anemia were insufficiently ordered. It was also found that a significant majority of anemic patients who underwent etiological evaluation were not even adequately treated. Long-term follow up improved anemia treatment, and patients with improved anemia had better survival. In conclusion, we recommend an optimal evaluation of CKD patients with anemia and initiating treatment as early as possible.

Laboratory-based surveillance of chronic kidney disease in people with private health coverage in Brazil

BackgroundAlthough approximately 25% of Brazilians have private health coverage (PHC), studies on the surveillance of chronic kidney disease (CKD) in this population are scarce. The objective of this study was to estimate the prevalence of CKD in individuals under two PHC regimes in Brazil, who total 8,335,724 beneficiaries.MethodsOutpatient serum creatinine and proteinuria results of individuals from all five regions of Brazil, ≥ 18 years of age, and performed between 10/01/2021 and 10/31/2022, were analyzed through the own laboratory network database. People with serum creatinine measurements were evaluated for the prevalence and staging of CKD, and those with simultaneous measurements of serum creatinine and proteinuria were evaluated for the risk category of the disease. CKD was classified according to current guidelines and was defined as a glomerular filtration rate (GFR) < 60 ml/min/1.73 m² estimated by the 2021 CKD-EPI equation.ResultsThe number of adults with serum creatinine results was 1,508,766 (age 44.0 [IQR, 33.9–56.8] years, 62.3% female). The estimated prevalence of CKD was 3.8% (2.6%, 0.8%, 0.2% and 0.2% in CKD stages 3a, 3b, 4 and 5, respectively), and it was higher in males than females (4.0% vs. 3.7%, p < 0.001, respectively) and in older age groups (0.2% among 18-29-year-olds, 0.5% among 30-44-year-olds, 2.0% among 45-59-year-olds, 9.4% among 60-74-year-olds, and 32.4% among ≥ 75-year-olds, p < 0.001) Adults with simultaneous results of creatinine and proteinuria were 64,178 (age 57.0 [IQR, 44.8–67.3] years, 58.1% female). After adjusting for age and gender, 70.1% were in the low-risk category of CKD, 20.0% were in the moderate-risk category, 5.8% were in the high-risk category, and 4.1% were in the very high-risk category.ConclusionThe estimated prevalence of CKD was 3.8%, and approximately 10% of the participants were in the categories of high or very high-risk of the disease. While almost 20% of beneficiaries with PHC had serum creatinine data, fewer than 1% underwent tests for proteinuria. This study was one of the largest ever conducted in Brazil and the first one to use the 2021 CKD-EPI equation to estimate the prevalence of CKD.

Analyzing Longitudinal Health Screening Data with Feature Ensemble and Machine Learning Techniques: Investigating Diagnostic Risk Factors of Metabolic Syndrome for Chronic Kidney Disease Stages 3a to 3b.

Longitudinal data, while often limited, contain valuable insights into features impacting clinical outcomes. To predict the progression of chronic kidney disease (CKD) in patients with metabolic syndrome, particularly those transitioning from stage 3a to 3b, where data are scarce, utilizing feature ensemble techniques can be advantageous. It can effectively identify crucial risk factors, influencing CKD progression, thereby enhancing model performance. Machine learning (ML) methods have gained popularity due to their ability to perform feature selection and handle complex feature interactions more effectively than traditional approaches. However, different ML methods yield varying feature importance information. This study proposes a multiphase hybrid risk factor evaluation scheme to consider the diverse feature information generated by ML methods. The scheme incorporates variable ensemble rules (VERs) to combine feature importance information, thereby aiding in the identification of important features influencing CKD progression and supporting clinical decision making. In the proposed scheme, we employ six ML models-Lasso, RF, MARS, LightGBM, XGBoost, and CatBoost-each renowned for its distinct feature selection mechanisms and widespread usage in clinical studies. By implementing our proposed scheme, thirteen features affecting CKD progression are identified, and a promising AUC score of 0.883 can be achieved when constructing a model with them.

COMPARISON OF ANTI-PROTEINURIC EFFECTS OF AMLODIPINE AND CILNIDIPINE AS AN ADD-ON DRUG TO BASELINE MEDICATION IN HYPERTENSIVE CHRONIC KIDNEY DISEASE PATIENTS

Objectives: The objectives of the study were to compare the anti-proteinuric effects of amlodipine and cilnidipine in individuals with Chronic Kidney Disease (CKD) on baseline medication. Methods: This was a prospective observational study carried out in the Department of Nephrology at Government T.D. Medical College, Alappuzha spanning a duration of 1 year from January 2016 to December 2016. The study encompassed a total of 90 hypertensive CKD patients-45 were administered amlodipine and the remaining 45 were given cilnidipine in conjunction with their existing baseline medications. The inclusion criteria consisted of hypertensive CKD patients aged between 18 and 80 years possessing a Glomerular Filtration Rate (GFR) between 30 and 60 mL/min and exhibiting blood pressure readings surpassing 140/90 mmHg despite receiving a loop diuretic (Tab. Frusemide 80 mg BD), an α-blocker (Tab. Prazosin 10 mg BD) and a β-blocker (Tab. Metoprolol 50 mg BD) for a minimum duration of one month. The key parameters that were monitored were sitting systolic and diastolic blood pressure readings and proteinuria which was evaluated by determining the Urine Protein Creatinine (UPC) ratio using untimed random urine samples. The GFR was calculated utilizing the Cockcroft-Gault formula. Results: The number of patients who improved to stage 3A CKD from stage 3B CKD were more with cilnidipine which indicates its reno-protective action. Amlodipine was seen to have no effect on UPC ratio whereas cilnidipine decreased UPC ratio significantly. Conclusion: Unlike amlodipine, cilnidipine exhibits marked reduction in proteinuria and improved GFR thereby preventing progression of hypertensive CKD patients to end stage renal failure.

A real-world exploration into clinical outcomes of direct oral anticoagulant therapy in people with chronic kidney disease: a large hospital-based study.

There is limited evidence to support definite clinical outcomes of direct oral anticoagulant (DOAC) therapy in chronic kidney disease (CKD). By identifying the important variables associated with clinical outcomes following DOAC administration in patients in different stages of CKD, this study aims to assess this evidence gap. An anonymised dataset comprising 97,413 patients receiving DOAC therapy in a tertiary health setting was systematically extracted from the multidimensional electronic health records and prepared for analysis. Machine learning classifiers were applied to the prepared dataset to select the important features which informed covariate selection in multivariate logistic regression analysis. For both CKD and non-CKD DOAC users, features such as length of stay, treatment days, and age were ranked highest for relevance to adverse outcomes like death and stroke. Patients with Stage 3a CKD had significantly higher odds of ischaemic stroke (OR 2.45, 95% Cl: 2.10-2.86; p = 0.001) and lower odds of all-cause mortality (OR 0.87, 95% Cl: 0.79-0.95; p = 0.001) on apixaban therapy. In patients with CKD (Stage 5) receiving apixaban, the odds of death were significantly lowered (OR 0.28, 95% Cl: 0.14-0.58; p = 0.001), while the effect on ischaemic stroke was insignificant. A positive effect of DOAC therapy was observed in advanced CKD. Key factors influencing clinical outcomes following DOAC administration in patients in different stages of CKD were identified. These are crucial for designing more advanced studies to explore safer and more effective DOAC therapy for the population.

Aortic calcification is associated with the difference between invasive central and cuff-measured brachial blood pressure in chronic kidney disease.

Chronic kidney disease (CKD) is associated with accelerated vascular calcification and increased central systolic blood pressure when measured invasively (invCSBP) relative to cuff-based brachial systolic blood pressure (cuffSBP). The contribution of aortic wall calcification to this phenomenon has not been clarified. We therefore examined the effects of aortic calcification on cuffSBP and invCSBP in a cohort of patients representing all stages of CKD. During elective coronary angiography, invCSBP was measured in the ascending aorta with a fluid-filled catheter with simultaneous recording of cuffSBP using an oscillometric device. Furthermore, participants underwent a non-contrast computed tomography scan of the entire aorta with observer blinded calcification scoring of the aortic wall ad modum Agatston. We included 168 patients (mean age 67.0±10.5, 38 females) of whom 38 had normal kidney function, while 30, 40, 28, and 32 had CKD stage 3a, 3b, 4, and 5, respectively. Agatston scores adjusted for body surface area ranged from 48 to 40,165. We found that invCSBP increased 3.6 (95% confidence interval 1.4-5.7) mmHg relative to cuffSBP for every 10,000-increment in aortic Agatston score. This association remained significant after adjustment for age, diabetes, antihypertensive treatment, smoking, eGFR and BP level. No such association was found for diastolic BP. Patients with advanced aortic calcification have relatively higher invCSBP for the same cuffSBP as compared to patients with less calcification. Advanced aortic calcification in CKD may therefore result in hidden central hypertension despite apparently well-controlled cuffSBP.

Dysbiosis of Gut Microbiota in Patients with Chronic Kidney Disease.

Objective The gut bacterial microbiota is altered in patients with chronic kidney disease (CKD). However, the bacterial composition at each stage of CKD is unclear in these patients, including those receiving renal replacement therapy. We herein report the changes in the gut microbiota among patients with CKD. Methods A total of 93 individuals were recruited for the study. Seventy-three patients had stage 3-5 CKD, including those receiving renal replacement therapy (CKD group), and 20 were age- and sex-matched controls (CKD stage 1-2). The gut microbiome composition was analyzed using a 16S ribosomal RNA gene-based sequencing protocol. Results At the genus level, the butyrate-producing bacteria Lachnospira, Blautia, Coprococcus, Anaerostipes, and Roseburia were more abundant in the control group (linear discriminant analysis score of >3) than in the CKD group. Lachnospira was more abundant in the control group than in patients with CKD stage 3a. Compared to the control group, multiplex butyrate-producing bacteria were deficient in patients with CKD stage 3b-5D, including in patients receiving renal replacement therapy. Conclusion Our findings highlight the fact that the gut bacterial composition, including butyrate-producing bacteria, deteriorates from CKD stage 3b. Even after renal replacement therapy, the bacterial composition did not change.

Initiation patterns of anticoagulants for atrial fibrillation among older UK adults with and without chronic kidney disease, 2010–2020

BackgroundThere is a paucity of data on the initiation patterns of anticoagulants among older atrial fibrillation patients with and without chronic kidney disease (CKD).Setting and methodsWe used the UK Clinical...

Multicentre external validation of the prognostic model kidney failure risk equation in patients with CKD stages 3 and 4 in Peru: a retrospective cohort study

ObjectivesTo externally validate the four-variable kidney failure risk equation (KFRE) in the Peruvian population for predicting kidney failure at 2 and 5 years.DesignA retrospective cohort study.Setting17 primary care centres from...

Association between Chronic Kidney Disease and Dynapenia in Elderly Koreans.

Chronic kidney disease (CKD) is caused by various factors such as chronic inflammation, oxidative stress, and obesity. Loss of muscle strength and mass is a negative prognostic factor for CKD. Therefore, in this study, we aimed to investigate the association between CKD and dynapenia in the Korean elderly. To this end, we analyzed 7029 participants from the 2014-2019 Korean National Health and Nutrition Examination Survey (KNHANES) aged ≥65 years. After adjusting for all of the covariates that could affect the results, such as physical examinations, lifestyle factors, and exercise, the association between CKD and dynapenia was found to be significant, at 1.207 (95% CI: 1.056-1.379) in CKD stage 2 and 1.790 (95% CI: 1.427-2.246) in CKD stage 3a-5. However, when sexes were analyzed separately, women were significant in both CKD stage 2 and stage 3-5 compared to normal, but only in stage 3-5 for men. Additionally, the prevalence of dynapenia increased significantly as the stage of CKD increased (normal, stage 2, and stage 3-5: 18.5%, 20.8%, and 32.3% in men and 27.5%, 34.4%, and 46.1% in women, respectively). Thus, CKD is significantly related to dynapenia, especially in women, when stratified by sex.

Abstract 16776: Recurrent Admission of Acute Decompensated Heart Failure Among Patients With and Without PAD and Its Significance in the CKD Population: The ARIC Cohort Study

Introduction: Peripheral artery disease (PAD) and chronic kidney disease (CKD) are common comorbidities in patients with heart failure (HF). Importantly, CKD is associated with a greater risk of incident PAD and is a known risk factor for worse outcomes in HF patients. However, it is unclear whether the concomitant existence of PAD and CKD increases the risk of recurrent hospitalization for acute decompensated heart failure (ADHF). Methods: Since 2005, the Atherosclerosis Risk in Communities (ARIC) study has conducted hospital surveillance of ADHF with events verified by physician review. Demographics, comorbidities, laboratory data, and medications were abstracted from medical record by trained personnel. Hazard ratios of ADHF readmissions were analyzed using repeat-events Cox regression. Models were adjusted for age, race, sex, year and hospital of admission, coronary artery disease (CAD), COPD, and diabetes mellitus. CKD was defined by glomerular filtration rate [GFR] ≤60 mL/min/1.73m 2 . Results: From 2005-2018, there were 1049 index hospitalizations for ADHF (mean age 77 years, 66% white) with measured creatinine, who were discharged alive. Of these, 155 (15%) had a diagnosis of PAD and 66% had CKD stage 3a or worse (GFR ≤60 mL/min/1.73m 2 ). Patients with PAD had a greater prevalence of smoking, CAD, myocardial infarction, and stroke. The 1-year ADHF readmission rate tended to be higher in patients with PAD, irrespective of CKD stage, compared to those without PAD ( Figure 1 ). After adjustments, PAD was associated with greater hazards of 1-year ADHF readmissions, both in patients with CKD stage 3a or worse (HR, 1.71; 95% CI: 1.25 - 2.32) and without CKD (HR, 1.84; 95% CI: 1.07-3.15). Conclusion: Patients with ADHF and concomitant PAD have a higher prevalence of cardiovascular comorbidities and higher likelihood of 1-year ADHF readmission, irrespective of the CKD status. Focused strategies to prevent ADHF readmission in this high-risk group are warranted.