Incident heart failure in chronic kidney disease: proteomics informs biology and risk stratification

BACKGROUND AND AIMS

Incident heart failure (HF) among individuals with chronic kidney disease (CKD) incurs hospitalizations that burden patients and health care systems. There are few preventative therapies, and the Pooled Cohort equations to Prevent Heart Failure (PCP-HF) perform poorly in the setting of CKD. New drug targets and better risk stratification are urgently needed.

METHODS

In this analysis of incident HF, SomaScan V4.0 (4638 proteins) was analysed in 2906 participants of the Chronic Renal Insufficiency Cohort (CRIC) with validation in the Atherosclerosis Risk in Communities (ARIC) study. The primary outcome was 14-year incident HF (390 events); secondary outcomes included 4-year HF (183 events), HF with reduced ejection fraction (137 events), and HF with preserved ejection fraction (165 events). Mendelian randomization and Gene Ontology were applied to examine causality and pathways. The performance of novel multi-protein risk models was compared to the PCP-HF risk score.

RESULTS

Over 200 proteins were associated with incident HF after adjustment for estimated glomerular filtration rate at P < 1 × 10-5. After adjustment for covariates including N-terminal pro-B-type natriuretic peptide, 17 proteins remained associated at P < 1 × 10-5. Mendelian randomization associations were found for six proteins, of which four are druggable targets: FCG2B, IGFBP3, CAH6, and ASGR1. For the primary outcome, the C-statistic (95% confidence interval [CI]) for the 48-protein model in CRIC was 0.790 (0.735, 0.844) vs. 0.703 (0.644, 0.762) for the PCP-HF model (P = .001). C-statistic (95% CI) for the protein model in ARIC was 0.747 (0.707, 0.787).

CONCLUSIONS

Large-scale proteomics reveal novel circulating protein biomarkers and potential mediators of HF in CKD. Proteomic risk models improve upon the PCP-HF risk score in this population.

Prognostic utility of rhythmic components in 24-h ambulatory blood pressure monitoring for the risk stratification of chronic kidney disease patients with cardiovascular co-morbidity

Chronic kidney disease (CKD) represents a significant global burden. Hypertension is a modifiable risk factor for rapid progression of CKD. We extend the risk stratification by introducing the non-parametric determination of rhythmic components in 24-h profiles of ambulatory blood pressure monitoring (ABPM) in the Chronic Renal Insufficiency Cohort (CRIC) and the African American Study for Kidney Disease and Hypertension (AASK) cohort using Cox proportional hazards models. We find that rhythmic profiling of BP through JTK_CYCLE analysis identifies subgroups of CRIC participants that were more likely to die due to cardiovascular causes. While our fully adjusted model shows a trend towards a significant association between absent cyclic components and cardiovascular death in the full CRIC cohort (HR: 1.71,95% CI: 0.99-2.97, p = 0.056), CRIC participants with a history of cardiovascular disease (CVD) and absent cyclic components in their BP profile had at any time a 3.4-times higher risk of cardiovascular death than CVD patients with cyclic components present in their BP profile (HR: 3.37, 95% CI: 1.45-7.87, p = 0.005). This increased risk was not explained by the dipping or non-dipping pattern in ABPM. Due to the large differences in patient characteristics, the results do not replicate in the AASK cohort. This study suggests rhythmic blood pressure components as a potential novel biomarker to unmask excess risk among CKD patients with prior cardiovascular disease.

Intensive Care Admissions and Outcome of Cardiac Arrests; A National Cohort Study From the United States

OBJECTIVE

Outcomes of cardiac arrest among patients who had cardiopulmonary resuscitation (CPR) in intensive care units (ICU) has limited data on the national level basis in the United States. We aimed to study the outcomes of ICU CPRs.

METHODS

Data from the national readmissions database (NRD) sample that constitutes 49.1% of the stratified sample of all hospitals in the United States were analyzed for ICU-related hospitalizations for the years 2016 to 2019. ICU CPR was defined by procedure codes.

RESULTS

A total of 4,610,154 ICU encounters were reported for the years 2016 to 2019 in the NRD. Of these patients, 426,729 (9.26%) had CPR procedure recorded during the hospital encounter (mean age 65 ± 17.81; female 42.4%). And 167,597 (39.29%) patients had CPR on the day of admission, of which 63.16% died; while 64,752 (15.18%) patients had CPR on the day of ICU admission, of which 72.85% died. And 36,002 (8.44%) had CPR among patients with length of stay 2 days, of which 73.34% died. A total of 1,222,799 (26.5%) admitted to ICU died, and patients who had ICU CPR had higher mortality, 291,391(68.3%). Higher complication rates were observed among ICU CPR patients, especially who died. Over the years from 2016 to 2019, ICU CPR rates increased from 8.18% (2016) to 8.66% (2019); p-trend = 0.001. The mortality rates among patients admitted to ICU increased from 22.1% (2016) to 24.1% (2019); p-trend = 0.005.

CONCLUSION

The majority of ICU CPRs were done on the first day of ICU admission. The trend for ICU CPR was increasing. The mortality trend for overall ICU admissions has increased, which is concerning and would suggest further research to improve the high mortality rates in the CPR group.

Salt-losing nephropathy associated with severe hypothyroidism

Here, we present a case of an older man presenting with worsening confusion. Laboratory tests showed serum sodium of 120 mmol/L with severe hypothyroidism and renal salt wasting that improved with treatment of hypothyroidism, normalising the serum sodium.

Association of urine and plasma ADMA with atherosclerotic risk in DKD cardiovascular disease risk in diabetic kidney disease: findings from the Chronic Renal Insufficiency Cohort (CRIC) study

BACKGROUND

Chronic kidney disease (CKD) is associated with atherosclerotic cardiovascular disease (ASCVD) risk, especially among those with diabetes. Altered metabolism of solutes that accumulate in CKD [asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and trimethylamine N-oxide (TMAO)] may reflect pathways linking CKD with ASCVD.

METHODS

This case-cohort study included Chronic Renal Insufficiency Cohort participants with baseline diabetes, estimated glomerular filtration rate <60 mL/min/1.73 m2, and without prior history for each outcome. The primary outcome was incident ASCVD (time to first myocardial infarction, stroke or peripheral artery disease event) and secondary outcome was incident heart failure. The subcohort comprised randomly selected participants meeting entry criteria. Plasma and urine ADMA, SDMA and TMAO concentrations were determined by liquid chromatography-tandem mass spectrometry. Associations of uremic solute plasma concentrations and urinary fractional excretions with outcomes were evaluated by weighted multivariable Cox regression models, adjusted for confounding covariables.

RESULTS

Higher plasma ADMA concentrations (per standard deviation) were associated with ASCVD risk [hazard ratio (HR) 1.30, 95% confidence interval (CI) 1.01-1.68]. Lower fractional excretion of ADMA (per standard deviation) was associated with ASCVD risk (HR 1.42, 95% CI 1.07-1.89). The lowest quartile of ADMA fractional excretion was associated with greater ASCVD risk (HR 2.25, 95% CI 1.08-4.69) compared with the highest quartile. Plasma SDMA and TMAO concentration and fractional excretion were not associated with ASCVD. Neither plasma nor fractional excretion of ADMA, SDMA and TMAO were associated with incident heart failure.

CONCLUSION

These data suggest that decreased kidney excretion of ADMA leads to increased plasma concentrations and ASCVD risk.

Clustering-based spatial analysis (CluSA) framework through graph neural network for chronic kidney disease prediction using histopathology images

Machine learning applied to digital pathology has been increasingly used to assess kidney function and diagnose the underlying cause of chronic kidney disease (CKD). We developed a novel computational framework, clustering-based spatial analysis (CluSA), that leverages unsupervised learning to learn spatial relationships between local visual patterns in kidney tissue. This framework minimizes the need for time-consuming and impractical expert annotations. 107,471 histopathology images obtained from 172 biopsy cores were used in the clustering and in the deep learning model. To incorporate spatial information over the clustered image patterns on the biopsy sample, we spatially encoded clustered patterns with colors and performed spatial analysis through graph neural network. A random forest classifier with various groups of features were used to predict CKD. For predicting eGFR at the biopsy, we achieved a sensitivity of 0.97, specificity of 0.90, and accuracy of 0.95. AUC was 0.96. For predicting eGFR changes in one-year, we achieved a sensitivity of 0.83, specificity of 0.85, and accuracy of 0.84. AUC was 0.85. This study presents the first spatial analysis based on unsupervised machine learning algorithms. Without expert annotation, CluSA framework can not only accurately classify and predict the degree of kidney function at the biopsy and in one year, but also identify novel predictors of kidney function and renal prognosis.

Proteomic cardiovascular risk assessment in chronic kidney disease

AIMS

Chronic kidney disease (CKD) is widely prevalent and independently increases cardiovascular risk. Cardiovascular risk prediction tools derived in the general population perform poorly in CKD. Through large-scale proteomics discovery, this study aimed to create more accurate cardiovascular risk models.

METHODS AND RESULTS

Elastic net regression was used to derive a proteomic risk model for incident cardiovascular risk in 2182 participants from the Chronic Renal Insufficiency Cohort. The model was then validated in 485 participants from the Atherosclerosis Risk in Communities cohort. All participants had CKD and no history of cardiovascular disease at study baseline when ∼5000 proteins were measured. The proteomic risk model, which consisted of 32 proteins, was superior to both the 2013 ACC/AHA Pooled Cohort Equation and a modified Pooled Cohort Equation that included estimated glomerular filtrate rate. The Chronic Renal Insufficiency Cohort internal validation set demonstrated annualized receiver operating characteristic area under the curve values from 1 to 10 years ranging between 0.84 and 0.89 for the protein and 0.70 and 0.73 for the clinical models. Similar findings were observed in the Atherosclerosis Risk in Communities validation cohort. For nearly half of the individual proteins independently associated with cardiovascular risk, Mendelian randomization suggested a causal link to cardiovascular events or risk factors. Pathway analyses revealed enrichment of proteins involved in immunologic function, vascular and neuronal development, and hepatic fibrosis.

CONCLUSION

In two sizeable populations with CKD, a proteomic risk model for incident cardiovascular disease surpassed clinical risk models recommended in clinical practice, even after including estimated glomerular filtration rate. New biological insights may prioritize the development of therapeutic strategies for cardiovascular risk reduction in the CKD population.

Prognostic utility of rhythmic components in 24-hour ambulatory blood pressure monitoring for the risk stratification of chronic kidney disease patients with cardiovascular co-morbidity

Background

Chronic kidney disease (CKD) represents a significant global burden. Hypertension is a modifiable risk factor for rapid progression of CKD.

Methods

We extend the risk stratification by introducing the non-parametric determination of rhythmic components in 24-hour profiles of ambulatory blood pressure monitoring (ABPM) in the African American Study for Kidney Disease and Hypertension (AASK) cohort and the Chronic Renal Insufficiency Cohort (CRIC) using Cox proportional hazards models.

Results

We find that rhythmic profiling of BP through JTK_Cycle analysis identifies subgroups of CRIC participants at advanced risk of cardiovascular death. CRIC participants with a history of cardiovascular disease (CVD) and absent cyclic components in their BP profile had at any time a 3.4-times higher risk of cardiovascular death than CVD patients with cyclic components present in their BP profile (HR: 3.38, 95% CI: 1.45-7.88, p=0.005). This substantially increased risk was independent of whether ABPM followed a dipping or non-dipping pattern whereby non-dipping or reverse dipping were not significantly associated with cardiovascular death in patients with prior CVD (p>0.1). In the AASK cohort, unadjusted models demonstrate a higher risk in reaching end stage renal disease among participants without rhythmic ABPM components (HR:1.80, 95% CI: 1.10-2.96); however, full adjustment abolished this association.

Conclusions

This study proposes rhythmic blood pressure components as a novel biomarker to unmask excess risk among CKD patients with prior cardiovascular disease.

Clinical outcomes and 30-day readmissions for heart failure with reduced ejection fraction with cardiorenal syndrome: A National Cohort Study

BACKGROUND

Literature regarding outcomes of cardiorenal syndrome (CRS) among heart failure with reduced ejection fraction (HFrEF) is limited.

OBJECTIVE

To study the clinical outcomes and 30-day readmission rates of CRS patients with HFrEF.

METHODS

Data from the Nationwide Readmissions Database (NRD) that constitutes 49.1% of the stratified sample of all hospitals in the United States (US), representing >95% of the national population, was analyzed for the CRS with HFrEF visits from 2018 to 2019. CRS was defined by the ICD-10 codes.

RESULTS

Out of the 1,530,749 index CRS-related hospitalizations (mean age:64.37 ± 13.30 years; 38.6%females) 73,126 (6.0%) CKD I-II, 883,119 (72.6%) CKD III-IV, and 258,835 (21.3%) CKD V-and-more related encounters were recorded. Mortality was higher among CKD stage V-and-more in comparison to other subgroups(7.6%vs5.73%;p < 0.001). AKI with underlying CKD was more common among stage III-IV compared to other subgroups (55.9%vs43.7%;p < 0.001). Respiratory failure, the second major complication, was more common among stage V-and-more compared to other subgroups (32.5%vs30%;p < 0.001). The overall CRS-related 30-day readmission rate was 22.7%, with CKD V-and-more accounting for highest rates(29.89%), followed by CKD stage III-IV(20.05%) and CKD I-II(12.99%). The primary etiology for 30-day readmission was cardiovascular among all subgroups (54.2%, 54.6%, and 41.80%, which corresponds to CKD I-II, CKD III-IV and CKD V-and-more, respectively).

CONCLUSION

CRS among HFrEF accounts for substantial healthcare burden with high 30-day readmission rates. Higher all-cause mortality and 30-day readmissions were associated with worse renal disease. This would suggest that more vigilance is needed by physicians for discharge planning among this patient population.

Multi-Scalar Data Integration Links Glomerular Angiopoietin-Tie Signaling Pathway Activation With Progression of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD). Prognostic biomarkers reflective of underlying molecular mechanisms are critically needed for effective management of DKD. A three-marker panel was derived from a proteomics analysis of plasma samples by an unbiased machine learning approach from participants (N = 58) in the Clinical Phenotyping and Resource Biobank study. In combination with standard clinical parameters, this panel improved prediction of the composite outcome of ESKD or a 40% decline in glomerular filtration rate. The panel was validated in an independent group (N = 68), who also had kidney transcriptomic profiles. One marker, plasma angiopoietin 2 (ANGPT2), was significantly associated with outcomes in cohorts from the Cardiovascular Health Study (N = 3,183) and the Chinese Cohort Study of Chronic Kidney Disease (N = 210). Glomerular transcriptional angiopoietin/Tie (ANG-TIE) pathway scores, derived from the expression of 154 ANG-TIE signaling mediators, correlated positively with plasma ANGPT2 levels and kidney outcomes. Higher receptor expression in glomeruli and higher ANG-TIE pathway scores in endothelial cells corroborated potential functional effects in the kidney from elevated plasma ANGPT2 levels. Our work suggests that ANGPT2 is a promising prognostic endothelial biomarker with likely functional impact on glomerular pathogenesis in DKD.

Black and White Adults With CKD Hospitalized With Acute Kidney Injury: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVE

Few studies have investigated racial disparities in acute kidney injury (AKI), in contrast to the extensive literature on racial differences in the risk of kidney failure. We sought to study potential differences in risk in the setting of chronic kidney disease (CKD).

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

We studied 2,720 self-identified Black or White participants with CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study from July 1, 2013, to December 31, 2017.

EXPOSURE

Self-reported race (Black vs White).

OUTCOME

Hospitalized AKI (≥50% increase from nadir to peak serum creatinine).

ANALYTICAL APPROACH

Cox regression models adjusting for demographics (age and sex), prehospitalization clinical risk factors (diabetes, blood pressure, cardiovascular disease, estimated glomerular filtration rate, proteinuria, receipt of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers), and socioeconomic status (insurance status and education level). In a subset of participants with genotype data, we adjusted for apolipoprotein L1 gene (APOL1) high-risk status and sickle cell trait.

RESULTS

Black participants (n = 1,266) were younger but had a higher burden of prehospitalization clinical risk factors. The incidence rate of first AKI hospitalization among Black participants was 6.3 (95% CI, 5.5-7.2) per 100 person-years versus 5.3 (95% CI, 4.6-6.1) per 100 person-years among White participants. In an unadjusted Cox regression model, Black participants were at a modestly increased risk of incident AKI (HR, 1.22 [95% CI, 1.01-1.48]) compared with White participants. However, this risk was attenuated and no longer significant after adjusting for prehospitalization clinical risk factors (adjusted HR, 1.02 [95% CI, 0.83-1.25]). There were only 11 AKI hospitalizations among individuals with high-risk APOL1 risk status and 14 AKI hospitalizations among individuals with sickle cell trait.

LIMITATIONS

Participants were limited to research volunteers and potentially not fully representative of all CKD patients.

CONCLUSIONS

In this multicenter prospective cohort of CKD patients, racial disparities in AKI incidence were modest and were explained by differences in prehospitalization clinical risk factors.

Unsupervised machine learning for identifying important visual features through bag-of-words using histopathology data from chronic kidney disease

Pathologists use visual classification to assess patient kidney biopsy samples when diagnosing the underlying cause of kidney disease. However, the assessment is qualitative, or semi-quantitative at best, and reproducibility is challenging. To discover previously unknown features which predict patient outcomes and overcome substantial interobserver variability, we developed an unsupervised bag-of-words model. Our study applied to the C-PROBE cohort of patients with chronic kidney disease (CKD). 107,471 histopathology images were obtained from 161 biopsy cores and identified important morphological features in biopsy tissue that are highly predictive of the presence of CKD both at the time of biopsy and in one year. To evaluate the performance of our model, we estimated the AUC and its 95% confidence interval. We show that this method is reliable and reproducible and can achieve 0.93 AUC at predicting glomerular filtration rate at the time of biopsy as well as predicting a loss of function at one year. Additionally, with this method, we ranked the identified morphological features according to their importance as diagnostic markers for chronic kidney disease. In this study, we have demonstrated the feasibility of using an unsupervised machine learning method without human input in order to predict the level of kidney function in CKD. The results from our study indicate that the visual dictionary, or visual image pattern, obtained from unsupervised machine learning can predict outcomes using machine-derived values that correspond to both known and unknown clinically relevant features.

Acute myocardial infarction and acute heart failure among renal transplant recipients: a national readmissions database study

BACKGROUND

The literature on the mortality and 30-day readmissions for acute heart failure and for acute myocardial infarction among renal-transplant recipients is limited.

OBJECTIVE

To study the in-hospital mortality, cardiovascular complications, and 30-day readmissions among renal transplant recipients (RTRs).

METHODS

Data from the national readmissions database sample, which constitutes 49.1% of all hospitals in the United States and represents more than 95% of the stratified national population, was analyzed for the years 2012-2018 using billing codes.

RESULTS

A total of 588,668 hospitalizations in renal transplant recipients (mean age 57.7 ± 14.2 years; 44.5% female) were recorded in the study years. A total of 15,788 (2.7%) patients had a diagnosis of acute heart failure; 11,320 (71.7%) had acute heart failure with preserved ejection fraction and 4468 (28.3%) had acute heart failure with reduced ejection fraction; 17,256 (3%) patients had myocardial infarction, 3496 (20%) had ST-Elevation myocardial infarction while 13,969 (80%) had non-ST-elevation myocardial infarction. Overall, 11,675 (2%) renal-transplant patients died, of whom 757 (6.5%) had acute heart failure, 330 (2.8%) had acute reduced and 427 (3.7%) had acute preserved ejection fraction failure. Among 1652 (14.1%) patient deaths with myocardial infarction, 465 (4%) were ST-elevation- and 1187 (10.1%) were non-ST-Elevation-related. The absolute yearly mortality rate due to acute heart failure increased over the years 2012-2018 (p-trend 0.0002, 0.001, 0.002, 0.05, respectively), while the mortality rate due to myocardial infarction with ST-elevation decreased (p-trend 0.002).

CONCLUSION

Cardiovascular complications are significantly associated with hospitalizations among RTRs. The absolute yearly mortality, and rate of heart failure (with reduced or preserved ejection fraction) increased over the study years, suggesting that more research is needed to improve the management of these patients.

Spontaneous retroperitoneal haemorrhage secondary to anticoagulation polypharmacy

Retroperitoneal haemorrhage (RH) is not uncommon in patients with provoking events like trauma. However, spontaneous RH (SRH) is a rare and life-threatening complication described as the development of bleeding into the retroperitoneal cavity, appearing spontaneously and without a preceding history of trauma or other predisposing illness. We are reporting a case of an elderly patient with recurrent deep vein thrombosis who had developed SRH secondary to concurrent use of multiple anticoagulation agents, resulting from poor healthcare follow-up and lack of sufficient medication reconciliation. This article highlights the significance of recognising risk factors for SRH, as well as management strategies through literature review.

Plasma Metabolomic Signatures of Healthy Dietary Patterns in the Chronic Renal Insufficiency Cohort (CRIC) Study

BACKGROUND

In individuals with chronic kidney disease (CKD), healthy dietary patterns are inversely associated with CKD progression. Metabolomics, an approach that measures many small molecules in biofluids, can identify biomarkers of healthy dietary patterns.

OBJECTIVES

We aimed to identify known metabolites associated with greater adherence to 4 healthy dietary patterns in CKD patients.

METHODS

We examined associations between 486 known plasma metabolites and Healthy Eating Index (HEI)-2015, Alternative Healthy Eating Index (AHEI)-2010, the Dietary Approaches to Stop Hypertension (DASH) diet, and alternate Mediterranean diet (aMED) in 1056 participants (aged 21-74 y at baseline) in the Chronic Renal Insufficiency Cohort (CRIC) Study. Usual dietary intake was assessed using a semiquantitative FFQ. We conducted multivariable linear regression models to study associations between healthy dietary patterns and individual plasma metabolites, adjusting for sociodemographic characteristics, health behaviors, and clinical factors. We used principal component analysis to identify groups of metabolites associated with individual food components within healthy dietary patterns.

RESULTS

After Bonferroni correction, we identified 266 statistically significant diet-metabolite associations (HEI: n = 60; AHEI: n = 78; DASH: n = 77; aMED: n = 51); 78 metabolites were associated with >1 dietary pattern. Lipids with a longer acyl chain length and double bonds (unsaturated) were positively associated with all 4 dietary patterns. A metabolite pattern low in saturated diacylglycerols and triacylglycerols, and a pattern high in unsaturated triacylglycerols was positively associated with intake of healthy food components. Plasmalogens were negatively associated with the consumption of nuts and legumes and healthy fat, and positively associated with the intake of red and processed meat.

CONCLUSIONS

We identified many metabolites associated with healthy dietary patterns, indicative of food consumption. If replicated, these metabolites may be considered biomarkers of healthy dietary patterns in patients with CKD.

Discontinuation of Intermittent Hemodialysis in HIV-Associated Nephropathy Following Initiation of Antiretroviral Therapy

Human immunodeficiency virus (HIV) infection occurs due to the HIV virus. It results in an immunodeficient state and multi-organ system infections and malignancy known as AIDS. HIV-associated nephropathy (HIVAN) is the most common HIV kidney involvement and may present as acute kidney injury (AKI), as well as chronic kidney disease (CKD). HIVAN is a collapsing form of focal segmental glomerulosclerosis (FSGS). HIVAN treatment options include antiretroviral therapy (ART), steroids, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB), and hemodialysis (HD). We herein describe the case of a 40-year-old patient with an established diagnosis of HIVAN who has had partial recovery of end-stage renal failure following the initiation of ART.

A Healthy Beverage Score and Risk of Chronic Kidney Disease Progression, Incident Cardiovascular Disease, and All-Cause Mortality in the Chronic Renal Insufficiency Cohort

BACKGROUND

Beverages are a source of calories and other bioactive constituents but are an understudied aspect of the diet. Different beverages have varying effects on health outcomes.

OBJECTIVES

We created the Healthy Beverage Score (HBS) to characterize participants' beverage patterns and examined its association with chronic kidney disease (CKD) progression, incident cardiovascular disease (CVD), and all-cause mortality among individuals with CKD.

METHODS

We conducted a prospective analysis of 2283 adults aged 21-74 y with a baseline estimated glomerular filtration rate of 20-70 mL · min-1 · 1.73 m-2 from the Chronic Renal Insufficiency Cohort. Diet was assessed using a 124-item FFQ at visit 1 (2003-2008). The HBS, ranging from 7 to 28 possible points, consisted of 7 components, each scored from 1 to 4 based on rank distribution by quartile, except alcohol, which was based on sex-specific cutoffs. Participants were given more points for higher consumption of low-fat milk and of coffee/tea, for moderate alcohol, and for lower consumption of 100% fruit juice, whole-fat milk, artificially sweetened beverages, and sugar-sweetened beverages. CKD progression, incident CVD, and mortality were ascertained through January 2018. We conducted multivariable Cox proportional hazards models.

RESULTS

There were 815 cases of CKD progression, 285 cases of incident CVD, and 725 deaths over a maximum of 14 y of follow-up. Compared with participants in the lowest tertile of the HBS, participants in the highest tertile had a 25% lower likelihood of CKD progression (HR: 0.75; 95% CI: 0.63, 0.89; P-trend = 0.001) and a 17% lower likelihood of all-cause mortality (HR: 0.83; 95% CI: 0.69, 1.00; P-trend = 0.04) after adjusting for sociodemographic, clinical, and dietary factors. There was no significant trend for incident CVD.

CONCLUSIONS

Among individuals with CKD, a healthier beverage pattern was inversely associated with CKD progression and all-cause mortality. Beverage intake may be an important modifiable target in preventing adverse outcomes for individuals with CKD.

Burden and Outcomes of Heart Failure Hospitalizations in Adults With Chronic Kidney Disease

BACKGROUND

Data on rates of heart failure (HF) hospitalizations, recurrent hospitalizations, and outcomes related to HF hospitalizations in chronic kidney disease (CKD) are limited.

OBJECTIVES

This study examined rates of HF hospitalizations and re-hospitalizations within a large CKD population and evaluated the burden of HF hospitalizations with the risk of subsequent CKD progression and death.

METHODS

The prospective CRIC (Chronic Renal Insufficiency Cohort) study measured the estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (ACR) at baseline. The crude rates and rate ratios of HF hospitalizations and 30-day HF re-hospitalizations were calculated using Poisson regression models. Cox regression was used to assess the association of the frequency of HF hospitalizations within the first 2 years of follow-up with risk of subsequent CKD progression and death.

RESULTS

Among 3,791 participants, the crude rate of HF admissions was 5.8 per 100 person-years (with higher rates of HF with preserved ejection fraction vs. HF with reduced ejection fraction). The adjusted rate of HF was higher with a lower eGFR (vs. eGFR >45 ml/min/1.73 m²); the rate ratios were 1.7 and 2.2 for eGFR 30 to 44 and <30 ml/min/1.73 m² (vs. >45 ml/min/1.73 m²), respectively. Similarly, the adjusted rates of HF hospitalization were significantly higher in those with higher urine ACR (vs. urine ACR <30 mg/g); the rate ratios were 1.9 and 2.6 for urine ACR 30 to 299 and ≥300 mg/g, respectively. Overall, 20.6% of participants had a subsequent HF re-admission within 30 days. HF hospitalization within 2 years of study entry was associated with greater adjusted risks for CKD progression (1 hospitalization: hazard ratio [HR]: 1.93; 95% confidence interval [CI]: 1.40 to 2.67; 2+ hospitalizations: HR: 2.14; 95% CI: 1.30 to 3.54) and all-cause death (1 hospitalization: HR: 2.20; 95% CI: 1.71 to 2.84; 2+ hospitalizations: HR: 3.06; 95% CI: 2.23 to 4.18).

CONCLUSIONS

Within a large U.S. CKD population, the rates of HF hospitalizations and re-hospitalization were high, with even higher rates across categories of lower eGFR and higher urine ACR. Patients with CKD hospitalized with HF had greater risks of CKD progression and death. HF prevention and treatment should be a public health priority to improve CKD outcomes.

Unique case of delayed external iliac artery pseudoaneurysm after a remote total hip arthroplasty

Vascular intrapelvic complications due to total hip arthroplasty failure are uncommon, with less than 30 cases reported in the literature. Herein, we report a case of unusual asymptomatic delayed vascular complication after 10 years from right total hip arthroplasty. A man in mid-50s, with multiple comorbidities including end-stage renal disease. The patient was admitted for the renal transplant surgery. Intraoperatively, right external iliac artery pseudoaneurysm was discovered, which required the transplantation to be done on the left side. After recovery from the renal transplant surgery, the patient underwent resection of the right external iliac artery pseudoaneurysm with primary anastomosis by vascular surgery, with resection of the migrated screw by orthopaedic surgery.

GDF-15, Galectin 3, Soluble ST2, and Risk of Mortality and Cardiovascular Events in CKD

RATIONALE & OBJECTIVE

Inflammation, cardiac remodeling, and fibrosis may explain in part the excess risk for cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). Growth differentiation factor 15 (GDF-15), galectin 3 (Gal-3), and soluble ST2 (sST2) are possible biomarkers of these pathways in patients with CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

Individuals with CKD enrolled in either of 2 multicenter CKD cohort studies: the Seattle Kidney Study or C-PROBE (Clinical Phenotyping and Resource Biobank Study).

EXPOSURES

Circulating GDF-15, Gal-3, and sST2 measured at baseline.

OUTCOMES

Primary outcome was all-cause mortality. Secondary outcomes included hospitalization for physician-adjudicated heart failure and the atherosclerotic CVD events of myocardial infarction and cerebrovascular accident.

ANALYTIC APPROACH

Cox proportional hazards models used to test the association of each biomarker with each outcome, adjusting for demographics, CVD risk factors, and kidney function.

RESULTS

Among 883 participants, mean estimated glomerular filtration rate was 49±19mL/min/1.73m². Higher GDF-15 (adjusted HR [aHR] per 1-SD higher, 1.87; 95% CI, 1.53-2.29), Gal-3 (aHR per 1-SD higher, 1.51; 95% CI, 1.36-1.78), and sST2 (aHR per 1-SD higher, 1.36; 95% CI, 1.17-1.58) concentrations were significantly associated with mortality. Only GDF-15 level was also associated with heart failure events (HR per 1-SD higher, 1.56; 95% CI, 1.12-2.16). There were no detectable associations between GDF-15, Gal-3, or sST2 concentrations and atherosclerotic CVD events.

LIMITATIONS

Event rates for heart failure and atherosclerotic CVD were low.

CONCLUSIONS

Adults with CKD and higher circulating GDF-15, Gal-3, and sST2 concentrations experienced greater mortality. Elevated GDF-15 concentration was also associated with an increased rate of heart failure. Further work is needed to elucidate the mechanisms linking these circulating biomarkers with CVD in patients with CKD.

Consent for Genetic Biobanking in a Diverse Multisite CKD Cohort

Introduction

The goal of this study was to examine patterns in the likelihood of consent to genetic research among participants in a prospective kidney disease cohort and biobank, and to determine demographic, clinical, and socioeconomic factors linked to consent for ongoing and future genetic research.

Methods

The Clinical Phenotyping Resource and Biobank Core (C-PROBE) enrolled 1628 adult and pediatric patients with chronic kidney disease from 2009 to 2017 across 7 sites in the United States. Participants were asked at annual study visits for consent to provide DNA samples for future genetic studies. We compared characteristics of participants by initial consent outcome and consent status at their most recent study visit.

Results

Of the C-PROBE participants, 96% consented to genetic studies at their initial study visit. Although African Americans were slightly less likely to consent at baseline (93% vs. 97%, odds ratio = 0.3, P < 0.02), there were no significant racial or ethnic differences with longitudinal participation. Also, pediatric and adult genetic consent rates were equivalent. The major persistent differences in the likelihood of consent were based on enrollment site, which ranged from 85% to 100% (P < 0.0001).

Conclusion

Overall, genetic consent rates for kidney research within the C-PROBE cohort were high. However, differences in consent rates over time and by recruitment site highlight the complexity of genetic consent for biobanking, and potential limitations for generalizability of observations.

C1q Nephropathy: The Unique Underrecognized Pathological Entity

C1q nephropathy is a rare glomerular disease with characteristic mesangial C1q deposition noted on immunofluorescence microscopy. It is histologically defined and poorly understood. Light microscopic features are heterogeneous and comprise minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and proliferative glomerulonephritis. Clinical presentation is also diverse, and ranges from asymptomatic hematuria or proteinuria to frank nephritic or nephrotic syndrome in both children and adults. Hypertension and renal insufficiency at the time of diagnosis are common findings. Optimal treatment is not clear and is usually guided by the underlying light microscopic lesion. Corticosteroids are the mainstay of treatment, with immunosuppressive agents reserved for steroid resistant cases. The presence of nephrotic syndrome and FSGS appear to predict adverse outcomes as opposed to favorable outcomes in those with MCD. Further research is needed to establish C1q nephropathy as a universally recognized distinct clinical entity. In this paper, we discuss the current understanding of pathogenesis, histopathology, clinical features, therapeutic options, and outcomes of C1q nephropathy.

A rare case of hyperammonemia complication of high-protein parenteral nutrition

Hyperammonemia is a metabolic derangement that can be potentially fatal. Primary hyperammonemia due to urea cycle enzyme deficiency is usually discovered in neonates but rarely can present in adulthood. Late-onset manifestations of urea cycle disorders can go unnoticed, until they become life threatening. The authors report a 28-year-old man who developed hyperammonemia in the hospital following parenteral nutrition (PN), leading to cerebral edema, which was fatal despite resolution of the hyperammonemia with cessation of PN and the use of continuous renal replacement therapy.