Evaluation and Measurement Properties of a Patient-Reported Experience Measure for Home Dialysis

BACKGROUND

No previously validated patient-reported experience measures exist for use among patients undergoing home dialysis. We tested the Home Dialysis Care Experience survey, a newly developed 26-item experience measure, among patients from 30 dialysis facilities in the United States.

METHODS

Using mail and telephone survey modalities, we approached 1372 patients treated with peritoneal dialysis or home hemodialysis for participation. Using the results from completed surveys, we evaluated item calibration by assessing item floor and ceiling effects. We tested three sets of composite scores and used factor analysis to assess model fit for each. We evaluated associations of composite scores with global ratings and separately with patient and dialysis facility characteristics. Finally, we measured test-retest reliability in patients who completed the survey at two separate time points.

RESULTS

Overall, 495 eligible patients completed at least one survey (response rate 36%). Of these, 49 completed the survey in Spanish and 61 completed a second survey within 30 days. We did not detect significant floor or ceiling effects, except for one item that demonstrated >90% responses at the top response option. Analyses supported one 12-item composite scale with high internal consistency reliability: Quality of Home Dialysis Care and Operations (Cronbach alpha=0.85). This scale strongly correlated with overall staff rating ( r =0.73) and overall center rating ( r =0.70). Patient demographic and dialysis facility characteristics were not consistently associated with composite scale scores or overall staff or center ratings. Intraclass correlation coefficients in the test-retest population were 0.74 for the Quality scale, 0.88 for overall staff rating, and 0.90 for overall center rating.

CONCLUSIONS

The Home Dialysis Care Experience survey is a 26-item measure that includes one composite scale and two global rating scores and is an informative tool to evaluate patient experience of care for home dialysis.

A National Survey of Conservative Kidney Management Practices for Patients Who Forgo RRT

Key Points

In the largest survey of US nephrology providers on conservative kidney management (CKM), most reported limited experience with CKM and varied approaches and local resources to provide CKM. There is need to enhance provider training and surveillance of CKM practices and to develop models of CKM that optimize care delivery and outcomes for these patients.

Background

Clinical practice guidelines advocate for conservative kidney management (CKM), a planned, holistic, patient-centered approach to caring for patients who forgo initiation of RRT. Little is known about the extent to which current care practices meet these expectations.

Methods

We conducted a cross-sectional survey of a national sample of nephrology providers recruited through US professional societies between March and July 2022 and inquired about their experiences with caring for patients who forgo RRT and their capacity to provide CKM.

Results

Overall, 203 nephrology providers (age 47±12 years, 53.2% White, 66.0% female), of which 49.8% were nephrologists and 50.2% advanced practice providers, completed the survey. Most (70.3%) reported that <10% of their practice comprised patients who had forgone RRT. Most indicated that they always or often provided symptom management (81.8%), multidisciplinary care (68.0%), tools to support shared decision making about treatment of advanced kidney disease (66.3%), and psychological support (52.2%) to patients who forgo RRT, while less than half reported that they always or often provided staff training on the care of these patients (47.8%) and spiritual support (41.4%). Most providers reported always or often working with primary care (72.9%), palliative medicine (68.8%), hospice (62.6%), social work (58.1%), and dietitian (50.7%) services to support these patients, while only a minority indicated that they always or often offered chaplaincy (23.2%), physical and/or occupational therapy (22.8%), psychology or psychiatry (31.5%), and geriatric medicine (28.1%).

Conclusions

Many nephrology providers have limited experience with caring for patients who forgo RRT. Our findings highlight opportunities to optimize comprehensive CKM care for these patients.

Challenges and Opportunities for the Clinical Translation of Spatial Transcriptomics Technologies

Background

The first spatially resolved transcriptomics platforms, GeoMx (Nanostring) and Visium (10x Genomics) were launched in 2019 and were recognized as the method of the year by Nature Methods in 2020. The subsequent refinement and expansion of these and other technologies to increase -plex, work with formalin-fixed paraffin-embedded tissue, and analyze protein in addition to gene expression have only added to their significance and impact on the biomedical sciences. In this perspective, we focus on two platforms for spatial transcriptomics, GeoMx and Visium, and how these platforms have been used to provide novel insight into kidney disease. The choice of platform will depend largely on experimental questions and design. The application of these technologies to clinically sourced biopsies presents the opportunity to identify specific tissue biomarkers that help define disease etiology and more precisely target therapeutic interventions in the future.

Summary

In this review, we provide a description of the existing and emerging technologies that can be used to capture spatially resolved gene and protein expression data from tissue. These technologies have provided new insight into the spatial heterogeneity of diseases, how reactions to disease are distributed within a tissue, which cells are affected, and molecular pathways that predict disease and response to therapy.

Key Message

The upcoming years will see intense use of spatial transcriptomics technologies to better define the pathophysiology of kidney diseases and develop novel diagnostic tests to guide personalized treatments for patients.

Associations of Biomarkers of Tubular Injury and Inflammation with Biopsy Features in Type 1 Diabetes

BACKGROUND

Whether biomarkers of tubular injury and inflammation indicate subclinical structural kidney pathology early in type 1 diabetes remains unknown.

METHODS

We investigated associations of biomarkers of tubular injury and inflammation with kidney structural features in 244 adults with type 1 diabetes from the Renin-Angiotensin System Study, a randomized, placebo-controlled trial testing effects of enalapril or losartan on changes in glomerular, tubulointerstitial, and vascular parameters from baseline to 5-year kidney biopsies. Biosamples at biopsy were assessed for kidney injury molecule 1 (KIM-1), soluble TNF receptor 1 (sTNFR1), arginine-to-citrulline ratio in plasma, and uromodulin and epidermal growth factor (EGF) in urine. We examined cross-sectional correlations between biomarkers and biopsy features and baseline biomarker associations with 5-year changes in biopsy features.

RESULTS

Participants' mean age was 30 years (SD 10) and diabetes duration 11 years (SD 5); 53% were women. The mean GFR measured by iohexol disappearance was 128 ml/min per 1.73 m 2 (SD 19) and median urinary albumin excretion was 5 μ g/min (interquartile range, 3-8). KIM-1 was associated with most biopsy features: higher mesangial fractional volume (0.5% [95% confidence interval (CI), 0.1 to 0.9] greater per SD KIM-1), glomerular basement membrane (GBM) width (14.2 nm [95% CI, 6.5 to 22.0] thicker), cortical interstitial fractional volume (1.1% [95% CI, 0.6 to 1.6] greater), fractional volume of cortical atrophic tubules (0.6% [95% CI, 0.2 to 0.9] greater), and arteriolar hyalinosis index (0.03 [95% CI, 0.1 to 0.05] higher). sTNFR1 was associated with higher mesangial fractional volume (0.9% [95% CI, 0.5 to 1.3] greater) and GBM width (12.5 nm [95% CI, 4.5 to 20.5] thicker) and lower GBM surface density (0.003 μ m 2 / μ m 3 [95% CI, 0.005 to 0.001] lesser). EGF and arginine-to-citrulline ratio correlated with severity of glomerular and tubulointerstitial features. Baseline sTNFR1, uromodulin, and EGF concentrations were associated with 5-year glomerular and tubulointerstitial feature progression.

CONCLUSIONS

Biomarkers of tubular injury and inflammation were associated with kidney structural parameters in early type 1 diabetes and may be indicators of kidney disease risk.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Renin Angiotensin System Study (RASS/B-RASS), NCT00143949.

Integrated Analysis of Blood and Urine Biomarkers to Identify Acute Kidney Injury Subphenotypes and Associations With Long-term Outcomes

RATIONALE & OBJECTIVE

Acute kidney injury (AKI) is a heterogeneous clinical syndrome with varying causes, pathophysiology, and outcomes. We incorporated plasma and urine biomarker measurements to identify AKI subgroups (subphenotypes) more tightly linked to underlying pathophysiology and long-term clinical outcomes.

STUDY DESIGN

Multicenter cohort study.

SETTING & PARTICIPANTS

769 hospitalized adults with AKI matched with 769 without AKI, enrolled from December 2009 to February 2015 in the ASSESS-AKI Study.

PREDICTORS

29 clinical, plasma, and urinary biomarker parameters used to identify AKI subphenotypes.

OUTCOME

Composite of major adverse kidney events (MAKE) with a median follow-up period of 4.7 years.

ANALYTICAL APPROACH

Latent class analysis (LCA) and k-means clustering were applied to 29 clinical, plasma, and urinary biomarker parameters. Associations between AKI subphenotypes and MAKE were analyzed using Kaplan-Meier curves and Cox proportional hazard models.

RESULTS

Among 769 AKI patients both LCA and k-means identified 2 distinct AKI subphenotypes (classes 1 and 2). The long-term risk for MAKE was higher with class 2 (adjusted HR, 1.41 [95% CI, 1.08-1.84]; P=0.01) compared with class 1, adjusting for demographics, hospital level factors, and KDIGO stage of AKI. The higher risk of MAKE among class 2 was explained by a higher risk of long-term chronic kidney disease progression and dialysis. The top variables that were different between classes 1 and 2 included plasma and urinary biomarkers of inflammation and epithelial cell injury; serum creatinine ranked 20th out of the 29 variables for differentiating classes.

LIMITATIONS

A replication cohort with simultaneously collected blood and urine sampling in hospitalized adults with AKI and long-term outcomes was unavailable.

CONCLUSIONS

We identify 2 molecularly distinct AKI subphenotypes with differing risk of long-term outcomes, independent of the current criteria to risk stratify AKI. Future identification of AKI subphenotypes may facilitate linking therapies to underlying pathophysiology to prevent long-term sequalae after AKI.

PLAIN-LANGUAGE SUMMARY

Acute kidney injury (AKI) occurs commonly in hospitalized patients and is associated with high morbidity and mortality. The AKI definition lumps many different types of AKI together, but subgroups of AKI may be more tightly linked to the underlying biology and clinical outcomes. We used 29 different clinical, blood, and urinary biomarkers and applied 2 different statistical algorithms to identify AKI subtypes and their association with long-term outcomes. Both clustering algorithms identified 2 AKI subtypes with different risk of chronic kidney disease, independent of the serum creatinine concentrations (the current gold standard to determine severity of AKI). Identification of AKI subtypes may facilitate linking therapies to underlying biology to prevent long-term consequences after AKI.

Randomized crossover clinical trial of coenzyme Q10 and nicotinamide riboside in chronic kidney disease

BackgroundCurrent studies suggest mitochondrial dysfunction is a major contributor to impaired physical performance and exercise intolerance in chronic kidney disease (CKD). We conducted a clinical trial of coenzyme Q10 (CoQ10) and nicotinamide riboside (NR) to determine their impact on exercise tolerance and metabolic profile in patients with CKD.MethodsWe conducted a randomized, placebo-controlled, double-blind, crossover trial comparing CoQ10, NR, and placebo in 25 patients with an estimated glomerular filtration rate (eGFR) of less than 60mL/min/1.73 m2. Participants received NR (1,000 mg/day), CoQ10 (1,200 mg/day), or placebo for 6 weeks each. The primary outcomes were aerobic capacity measured by peak rate of oxygen consumption (VO2 peak) and work efficiency measured using graded cycle ergometry testing. We performed semitargeted plasma metabolomics and lipidomics.ResultsParticipant mean age was 61.0 ± 11.6 years and mean eGFR was 36.9 ± 9.2 mL/min/1.73 m2. Compared with placebo, we found no differences in VO2 peak (P = 0.30, 0.17), total work (P = 0.47, 0.77), and total work efficiency (P = 0.46, 0.55) after NR or CoQ10 supplementation. NR decreased submaximal VO2 at 30 W (P = 0.03) and VO2 at 60 W (P = 0.07) compared with placebo. No changes in eGFR were observed after NR or CoQ10 treatment (P = 0.14, 0.88). CoQ10 increased free fatty acids and decreased complex medium- and long-chain triglycerides. NR supplementation significantly altered TCA cycle intermediates and glutamate that were involved in reactions that exclusively use NAD+ and NADP+ as cofactors. NR decreased a broad range of lipid groups including triglycerides and ceramides.ConclusionsSix weeks of treatment with NR or CoQ10 improved markers of systemic mitochondrial metabolism and lipid profiles but did not improve VO2 peak or total work efficiency.Trial registrationClinicalTrials.gov NCT03579693.FundingNational Institutes of Diabetes and Digestive and Kidney Diseases (grants R01 DK101509, R03 DK114502, R01 DK125794, and R01 DK101509).

Mortality Burden and Life-Years Lost Across the Age Spectrum for Adults Living with CKD

Key Points

Limited data exist to inform younger persons with CKD how their risk for mortality compares with equivalently aged individuals without CKD. Compared with the general population without CKD, the age-stratified risk for mortality was highest in younger individuals with CKD. From a lifetime perspective, the estimated reduction of lifespan secondary to CKD was greatest at younger ages.

Background

Younger individuals living with CKD face a lifetime at risk for complications and mortality. Limited data exist to inform individual patients with CKD across the lifespan how their risk for mortality compares with equivalently aged individuals without CKD, particularly at younger ages. The objective of this study was to provide age-specific contexts to the risk of mortality associated with a diagnosis of CKD.

Methods

We created a pooled study cohort using participants with CKD enrolled in the Chronic Renal Insufficiency Cohort along with participants aged 21–75 years included in the 1999–2008 National Health and Nutrition Examination Survey surveys. Age-stratified mortality rates, along with unadjusted and adjusted hazard ratios (HRs) for mortality, were generated to compare differences between those with and without CKD. The mean life-years lost (LYL) relating to CKD was calculated using Centers for Disease Control and Prevention life tables.

Results

A total of 16,725 participants were included. Mortality rates were higher in those with CKD at all ages. The adjusted age-stratified HR for mortality in those with CKD versus without was highest in the 21–35 years strata (HR [95% confidence interval (CI)], 4.9 [2.8 to 8.6])) and lowest in the 65–75 years strata (HR [95% CI], 2.0 [1.7 to 2.3]). The mean LYL secondary to CKD was inversely related with increasing age.

Conclusions

Compared with age-matched peers without CKD, the age-stratified risk for mortality and LYL associated with a diagnosis of CKD is highest in younger individuals. Further research is needed to elucidate the societal and personal costs of premature mortality associated with CKD in young adults.

Value Placed on Comfort vs Life Prolongation Among Patients Treated With Maintenance Dialysis

Importance

Patients receiving maintenance dialysis experience intensive patterns of end-of-life care that might not be consistent with their values.

Objective

To evaluate the association of patients' health care values with engagement in advance care planning and end-of-life care.

Design, Setting, and Participants

Survey study of patients who received maintenance dialysis between 2015 and 2018 at dialysis centers in the greater metropolitan areas of Seattle, Washington, and Nashville, Tennessee, with longitudinal follow-up of decedents. Logistic regression models were used to estimate probabilities. Data analysis was conducted between May and October 2022.

Exposures

A survey question about the value that the participant would place on longevity-focused vs comfort-focused care if they were to become seriously ill.

Main Outcomes and Measures

Self-reported engagement in advance care planning and care received near the end of life through 2020 using linked kidney registry data and Medicare claims.

Results

Of 933 patients (mean [SD] age, 62.6 [14.0] years; 525 male patients [56.3%]; 254 [27.2%] identified as Black) who responded to the question about values and could be linked to registry data (65.2% response rate [933 of 1431 eligible patients]), 452 (48.4%) indicated that they would value comfort-focused care, 179 (19.2%) that they would value longevity-focused care, and 302 (32.4%) that they were unsure about the intensity of care they would value. Many had not completed an advance directive (estimated probability, 47.5% [95% CI, 42.9%-52.1%] of those who would value comfort-focused care vs 28.1% [95% CI, 24.0%-32.3%] of those who would value longevity-focused care or were unsure; P < .001), had not discussed hospice (estimated probability, 28.6% [95% CI, 24.6%-32.9%] comfort focused vs 18.2% [95% CI, 14.7%-21.7%] longevity focused or unsure; P < .001), or had not discussed stopping dialysis (estimated probability, 33.3% [95% CI, 29.0%-37.7%] comfort focused vs 21.9% [95% CI, 18.2%-25.8%] longevity focused or unsure; P < .001). Most respondents wanted to receive cardiopulmonary resuscitation (estimated probability, 78.0% [95% CI, 74.2%-81.7%] comfort focused vs 93.9% [95% CI, 91.4%-96.1%] longevity focused or unsure; P < .001) and mechanical ventilation (estimated probability, 52.0% [95% CI, 47.4%-56.6%] comfort focused vs 77.9% [95% CI, 74.0%-81.7%] longevity focused or unsure; P < .001). Among decedents, the percentages of participants who received an intensive procedure during the final month of life (estimated probability, 23.5% [95% CI, 16.5%-31.0%] comfort focused vs 26.1% [95% CI, 18.0%-34.5%] longevity focused or unsure; P = .64), discontinued dialysis (estimated probability, 38.3% [95% CI, 32.0%-44.8%] comfort focused vs 30.2% [95% CI, 23.0%-37.8%] longevity focused or unsure; P = .09), and enrolled in hospice (estimated probability, 32.2% [95% CI, 25.7%-38.7%] comfort focused vs 23.3% [95% CI, 16.4%-30.5%] longevity focused or unsure; P = .07) were not statistically different.

Conclusions and Relevance

This survey study found that there appeared to be a disconnect between patients' expressed values, which were largely comfort focused, and their engagement in advance care planning and end-of-life care, which reflected a focus on longevity. These findings suggest important opportunities to improve the quality of care for patients receiving dialysis.

A Patient Decision Aid About Conservative Kidney Management in Advanced Kidney Disease: A Randomized Pilot Trial

RATIONALE & OBJECTIVE

Available decision aids for patients about treatment of advanced chronic kidney disease (CKD) often lack information on conservative kidney management (CKM). We assessed the feasibility and acceptability of a decision aid on CKM among patients with advanced CKD and their family members.

STUDY DESIGN

Randomized pilot trial.

SETTING & PARTICIPANTS

Patients aged≥75 years with stage 4 or 5 CKD and their family members at 4 medical centers in the greater Seattle area between August 2020 and December 2021.

INTERVENTIONS

Usual care with or without a decision aid on CKM.

OUTCOME

Acceptability was assessed by attrition rates between the initial study visit (T1) and the 3-month follow-up evaluation (T3). The primary outcome and measure of feasibility was the proportion of participants who discussed CKM with a health care provider between T1 and T3.

RESULTS

We randomized 92 patients of whom 86 (55.8% male; age 82±6 years; 82.6% White) completed T1-42 in the usual care arm and 44 in the usual care plus decision aid arm-and 56 family members of whom 53 (18.9% male; age 71±11 years; 86.8% White) completed T1-20 in usual care arm and 33 in the usual care plus decisions aid arm. The attrition rates were 21% versus 21% (P=1.0) for patients, and 10% versus 18% (P=0.46) for family members in the usual care versus usual care plus decisions aid arms. Receipt of the decision aid significantly increased discussion of CKM with a health care provider for patients (26.4% vs 3.0%, P=0.007) and family members (26.9% vs 0, P=0.02).

LIMITATIONS

Possible limited generalizability because participants were a relatively homogenous group. The decision aid focuses on CKM and may be less applicable to those with limited knowledge of kidney replacement therapies.

CONCLUSIONS

A CKM decision aid was feasible and acceptable, and increased discussion of this treatment option with health care providers. This aid may serve as a useful adjunct to the currently available educational tools on treatments for advanced CKD.

FUNDING

Grant from a not-for-profit entity (National Palliative Care Research Center).

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT04919941.

Metabolomic Profiling Identifies New Endogenous Markers of Tubular Secretory Clearance

BACKGROUND

The proximal tubules eliminate protein-bound toxins and drugs through secretion. Measurements or estimates of GFR do not necessarily reflect the physiologically distinct process of secretion. Clinical assessment of this important intrinsic kidney function requires endogenous markers that are highly specific for secretory transport.

METHODS

We used metabolomics profiling to identify candidate markers of tubular secretory clearance in 50 participants from a kidney pharmacokinetics study. We measured metabolites in three sequential plasma samples and a concurrent 10-hour timed urine sample using hydrophilic interaction liquid chromatography/high-resolution mass spectrometry. We quantified the association between estimated kidney clearance and normalized plasma peak height of each candidate solute to the clearance of administered furosemide, a protein-bound, avidly secreted medication.

RESULTS

We identified 528 metabolites present in plasma and urine, excluding pharmaceuticals. We found seven highly (>50%) protein-bound and 49 poorly bound solutes with clearances significantly associated with furosemide clearance and 18 solute clearances favoring an association with furosemide clearance by the 90th percentile compared with GFR. We also found four highly bound and 42 poorly bound plasma levels that were significantly associated with furosemide clearance.

CONCLUSIONS

We found several candidate metabolites whose kidney clearances or relative plasma levels are highly associated with furosemide clearance, an avidly secreted tracer medication of the organic anion transporters, highlighting their potential as endogenous markers of proximal tubular secretory clearance.

Population-Based Limits of Urine Creatinine Excretion

Introduction

The validity of a timed urine collection is typically judged by measurement of urine creatinine excretion, but prevailing limits may be unreliable. We sought to empirically derive population-based limits of excretion for evaluating the validity of a timed urine collection.

Methods

Covariate and 24-hour urine data were obtained from 3582 participants in the Chronic Renal Insufficiency Cohort (CRIC) study, 814 participants in the Modification of Diet in Renal Disease (MDRD) study, 1010 participants in the Jackson Heart Study (JHS), and 8536 participants in the Prevention of Renal Vascular End Stage Disease (PREVEND) study. Weight, height, age, sex, and serum creatinine concentrations were evaluated as potential predictors of urine creatinine excretion using Akaike Information Criteria, R-squared values, and deviance. Bias and precision of the fitted models were assessed by analyses of residuals. Agreement between 24-hour creatinine clearance and 125I-iothalamate clearance was assessed before and after exclusion of potentially invalid urine samples.

Results

A best-fitting model to predict 24-hour urine creatinine excretion among the 9199 discovery cohort members included sex-specific terms for weight, height, and age (R-squared = 0.328). This model had a median bias of +4.3 mg creatinine/day (95% confidence interval -5.6, +13.3 mg/day) in 4599 validation cohort members, and 82% of observed values were within 30% of predicted model. Serum creatinine concentrations only marginally improved model precision but reduced bias in persons with advanced chronic kidney disease (CKD).

Conclusion

The limits of urine creatinine excretion derived here represent the most valid and representative data for appraising the adequacy of a timed urine collection.

Tubular Secretion and Estimated GFR Decline in the Jackson Heart Study

Introduction

Secretion of solutes by the proximal tubules represents an intrinsic kidney function not directly reflected by the glomerular filtration rate (GFR). The early loss of secretory clearance may reflect unrecognized kidney dysfunction, portending future disease progression.

Methods

We designed a nested case-control study within the Jackson Heart Study (JHS), a prospective study of African American adults in Mississippi, to associate baseline differences in proximal tubular secretion of 5 endogenously produced solutes with future estimated glomerular rate (eGFR) decline. We matched 127 pairs by creatinine-eGFR, age, diabetes, and sex among the patients who provided a 24-hour urine collection; cases had a ≥25% decline in eGFR compared to <10% in controls over 10 years of follow-up. We measured baseline plasma and urine concentrations of secretory solutes using liquid chromatography-mass spectrometry to determine the odds ratio of kidney disease progression.

Results

Mean age was 60 years; 76% were women; 30% had diabetes; mean baseline eGFR was 94±20 ml/min per 1.73 m². The eGFR decline over 10 years was 38±13% in cases and 0±10% in controls. After adjustment for the matching variables plus albuminuria, systolic blood pressure, body mass index, and smoking, each 50% lower kidney clearance of isovalerylglycine, kynurenic acid, and xanthosine were associated with 1.4 to 2.2 greater odds of eGFR decline. Kynurenic acid exhibited the strongest association; each 50% lower clearance of this secretory solute was associated with 2.20-fold higher odds of eGFR decline (95% confidence interval [CI] 1.32-3.67).

Conclusion

We found that in this community-based study of adults without significant kidney disease, lower proximal tubular secretory solute clearance is associated with future eGFR decline.

Rates of Cardiovascular Disease and CKD Progression in Young Adults with CKD across Racial and Ethnic Groups

Background

Significant racial and ethnic disparities in cardiovascular (CV) and kidney function outcomes in older adults with chronic kidney disease (CKD) have been reported. However, little is known about the extent to which these disparities exist in patients with CKD during the foundational period of young adulthood. The objective of this study was to determine risk factors and rates of CV disease and CKD progression in young adults with CKD across racial and ethnic groups.

Methods

We studied all participants aged 21-40 years of age enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study (n=317). Baseline CV risk factors were described across racial and ethnic groups.

Results

Outcomes included CV events or death (first incidence of heart failure, myocardial infarction, and stroke or death) and CKD progression (>50% decline in eGFR from baseline or end stage kidney disease [ESKD]). Incidence rate ratios (IRRs) were compared as a secondary analysis for participants identifying as Black or Hispanic with those identifying as White or another race and ethnicity. Adjusted models included age, sex, and per APOL1 high-risk allele. CV risk factors were higher in Black and Hispanic participants, including mean SBP, BMI, median UACr, and LDL. Black and Hispanic participants had higher incidence rates of HF (17.5 versus 5.1/1000 person-years), all-cause mortality (15.2 versus 7.1/1000 person-years), and CKD progression (125 versus 59/1000 person-years).

Conclusions

In conclusion, we found a higher prevalence of CV risk factors, some modifiable, in young adults with CKD who identify as Black or Hispanic. Future strategies to ameliorate the racial and ethnic inequality in health outcomes earlier in life for patients with CKD should be prioritized.

Clinical and biomarker modifiers of vitamin D treatment response: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Different 25-hydroxyvitamin D [25(OH)D] thresholds for treatment with vitamin D supplementation have been suggested and are derived almost exclusively from observational studies. Whether other characteristics, including race/ethnicity, BMI, and estimated glomerular filtration rate (eGFR), should also influence the threshold for treatment is unknown.

OBJECTIVES

The aim was to identify clinical and biomarker characteristics that modify the response to vitamin D supplementation.

METHODS

A total of 666 older adults in the Multi-Ethnic Study of Atherosclerosis (MESA) were randomly assigned to 16 wk of oral vitamin D3 (2000 IU/d; n = 499) or placebo (n = 167). Primary outcomes were changes in serum parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D [1,25(OH)2D] concentrations from baseline to 16 wk.

RESULTS

Among 666 participants randomly assigned (mean age: 72 y; 53% female; 66% racial/ethnic minority), 611 (92%) completed the study. The mean (SD) change in PTH was -3 (16) pg/mL with vitamin D3 compared with 2 (18) pg/mL with placebo (estimated mean difference: -5; 95% CI: -8, -2 pg/mL). Within the vitamin D3 group, lower baseline 25-hydroxyvitamin D [25(OH)D] was associated with a larger decline in PTH in a nonlinear fashion. With baseline 25(OH)D ≥30 ng/mL as the reference, 25(OH)D <20 ng/mL was associated with a larger decline in PTH with vitamin D3 supplementation (-10; 95% CI: -15, -6 pg/mL), whereas 25(OH)D of 20-30 ng/mL was not (-2; 95% CI: -6, 1 pg/mL). A segmented threshold model identified a baseline 25(OH)D concentration of 21 (95% CI: 13, 31) ng/mL as an inflection point for difference in change in PTH. Race/ethnicity, BMI, and eGFR did not modify vitamin D treatment response. There was no significant change in 1,25(OH)2D in either treatment group.

CONCLUSIONS

Of characteristics most commonly associated with vitamin D metabolism, only baseline 25(OH)D <20 ng/mL modified the PTH response to vitamin D supplementation, providing support from a clinical trial to use this threshold to define insufficiency. This trial was registered at clinicaltrials.gov as NCT02925195.

BP in Young Adults with CKD and Associations with Cardiovascular Events and Decline in Kidney Function

BACKGROUND

BP is an important modifiable risk factor for cardiovascular events and CKD progression in middle-aged or older adults with CKD. However, studies describing the relationship between BP with outcomes in young adults with CKD are limited.

METHODS

In an observational study, we focused on 317 young adults (aged 21-40 years) with mild to moderate CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. Exposures included baseline systolic BP evaluated continuously (per 10 mm Hg increase) and in categories (<120, 120-129, and ≥130 mm Hg). Primary outcomes included cardiovascular events (heart failure, myocardial infarction, stroke, or all-cause death) and CKD progression (50% decline of eGFR or ESKD). We used Cox proportional hazard models to test associations between baseline systolic BP with cardiovascular events and CKD progression.

RESULTS

Cardiovascular events occurred in 52 participants and 161 had CKD progression during median follow-up times of 11.3 years and 4.1 years, respectively. Among those with baseline systolic BP ≥130 mm Hg, 3%/yr developed heart failure, 20%/yr had CKD progression, and 2%/yr died. In fully adjusted models, baseline systolic BP ≥130 mm Hg (versus systolic BP<120 mm Hg) was significantly associated with cardiovascular events or death (hazard ratio [HR], 2.13; 95% confidence interval [95% CI], 1.05 to 4.32) and CKD progression (HR, 1.68; 95% CI, 1.10 to 2.58).

CONCLUSIONS

Among young adults with CKD, higher systolic BP is significantly associated with a greater risk of cardiovascular events and CKD progression. Trials of BP management are needed to test targets and treatment strategies specifically in young adults with CKD.

Post-resuscitation arterial oxygen and carbon dioxide and outcomes after out-of-hospital cardiac arrest

OBJECTIVE

To determine if arterial oxygen and carbon dioxide abnormalities in the first 24h after return of spontaneous circulation (ROSC) are associated with increased mortality in adult out-of-hospital cardiac arrest (OHCA).

METHODS

We used data from the Resuscitation Outcomes Consortium (ROC), including adult OHCA with sustained ROSC ≥1h after Emergency Department arrival and at least one arterial blood gas (ABG) measurement. Among ABGs measured during the first 24h of hospitalization, we identified the presence of hyperoxemia (PaO2≥300mmHg), hypoxemia (PaO2<60mmHg), hypercarbia (PaCO2>50mmHg) and hypocarbia (PaCO2<30mmHg). We evaluated the associations between oxygen and carbon dioxide abnormalities and hospital mortality, adjusting for confounders.

RESULTS

Among 9186 OHCA included in the analysis, hospital mortality was 67.3%. Hyperoxemia, hypoxemia, hypercarbia, and hypocarbia occurred in 26.5%, 19.0%, 51.0% and 30.6%, respectively. Initial hyperoxemia only was not associated with hospital mortality (adjusted OR 1.10; 95% CI: 0.97-1.26). However, final and any hyperoxemia (1.25; 1.11-1.41) were associated with increased hospital mortality. Initial (1.58; 1.30-1.92), final (3.06; 2.42-3.86) and any (1.76; 1.54-2.02) hypoxemia (PaO2<60mmHg) were associated with increased hospital mortality. Initial (1.89; 1.70-2.10); final (2.57; 2.18-3.04) and any (1.85; 1.67-2.05) hypercarbia (PaCO2>50mmHg) were associated with increased hospital mortality. Initial (1.13; 0.90-1.41), final (1.19; 1.04-1.37) and any (1.01; 0.91-1.12) hypocarbia (PaCO2<30mmHg) were not associated with hospital mortality.

CONCLUSIONS

In the first 24h after ROSC, abnormal post-arrest oxygen and carbon dioxide tensions are associated with increased out of-hospital cardiac arrest mortality.

Unchanged pediatric out-of-hospital cardiac arrest incidence and survival rates with regional variation in North America

AIM

Outcomes for pediatric out-of-hospital cardiac arrest (OHCA) are poor. Our objective was to determine temporal trends in incidence and mortality for pediatric OHCA.

METHODS

Adjusted incidence and hospital mortality rates of pediatric non-traumatic OHCA patients from 2007-2012 were analyzed using the 9 region Resuscitation Outcomes Consortium-Epidemiological Registry (ROC-Epistry) database. Children were divided into 4 age groups: perinatal (<3 days), infants (3days-1year), children (1-11 years), and adolescents (12-19 years). ROC regions were analyzed post-hoc.

RESULTS

We studied 1738 children with OHCA. The age- and sex-adjusted incidence rate of OHCA was 8.3 per 100,000 person-years (75.3 for infants vs. 3.7 for children and 6.3 for adolescents, per 100,000 person-years, p<0.001). Incidence rates differed by year (p<0.001) without overall linear trend. Annual survival rates ranged from 6.7-10.2%. Survival was highest in the perinatal (25%) and adolescent (17.3%) groups. Stratified by age group, survival rates over time were unchanged (all p>0.05) but there was a non-significant linear trend (1.3% increase) in infants. In the multivariable logistic regression analysis, infants, unwitnessed event, initial rhythm of asystole, and region were associated with worse survival, all p<0.001. Survival by region ranged from 2.6-14.7%. Regions with the highest survival had more cases of EMS-witnessed OHCA, bystander CPR, and increased EMS-defibrillation (all p<0.05).

CONCLUSIONS

Overall incidence and survival of children with OHCA in ROC regions did not significantly change over a recent 5year period. Regional variation represents an opportunity for further study to improve outcomes.

Design and implementation of the Resuscitation Outcomes Consortium Pragmatic Airway Resuscitation Trial (PART)

Airway management is an important component of resuscitation from out-of-hospital cardiac arrest (OHCA). The optimal approach to advanced airway management is unknown. The Pragmatic Airway Resuscitation Trial (PART) will compare the effectiveness of endotracheal intubation (ETI) and Laryngeal Tube (LT) insertion upon 72-h survival in adult OHCA. Encompassing United States Emergency Medical Services agencies affiliated with the Resuscitation Outcomes Consortium (ROC), PART will use a cluster-crossover randomized design. Participating subjects will include adult, non-traumatic OHCA requiring bag-valve-mask ventilation. Trial interventions will include (1) initial airway management with ETI and (2) initial airway management with LT. The primary and secondary trial outcomes are 72-h survival and return of spontaneous circulation. Additional clinical outcomes will include airway management process and adverse events. The trial will enroll a total of 3000 subjects. Results of PART may guide the selection of advanced airway management strategies in OHCA.

Association of advanced airway device with chest compression fraction during out-of-hospital cardiopulmonary arrest

BACKGROUND

Select Emergency Medical Services (EMS) practitioners substitute endotracheal intubation (ETI) with supraglottic airway (SGA) insertion to minimize CPR chest compression interruptions, but the resulting effects upon chest compression fraction (CCF) are unknown. We sought to determine the differences in CCF between adult out-of-hospital cardiac arrest (OHCA) receiving ETI and those receiving SGA.

METHODS

We studied adult, non-traumatic OHCA patients enrolled in the Resuscitation Outcomes Consortium (ROC) Prehospital Resuscitation using an Impedance valve and an Early vs. Delayed analysis (PRIMED) trial. Chest compressions were measured using compression or thoracic impedance sensors. We limited the analysis to those receiving ETI or SGA (Combitube, King Laryngeal Tube, or Laryngeal Mask Airway) and >2min of chest compression data before and after airway insertion. We compared CCF between ETI and SGA before and after airway insertion, adjusting for age, sex, witnessed arrest, bystander CPR, shockable initial rhythm, public location, PRIMED trial arm, and regional ROC center. We also compared the change in CCF for each airway technique.

RESULTS

Of 14,955 patients enrolled in the ROC PRIMED trial, we analyzed 2767 cases, including 2051 ETI, 671 SGA, and 45 both. Among subjects in this investigation the mean age was 66.4 years with a male predominace, 46% with witnessed event, 37% receiving bystander CPR, and 22% presenting with an initially shockable rhythm. Pre- and post-airway CCF was higher for SGA than ETI (SGA pre-airway CCF 73.2% [95%CI: 71.6-74.7%] vs. ETI 70.6% [95%CI: 69.7-71.5%]; post-airway 76.7% [95%CI: 75.2-78.1%] vs. 72.4% [95%CI: 71.5-73.3%]). After adjusting for potential confounders, these significant changes persisted (pre-airway difference 2.2% favoring SGA, p-value=0.046; post-airway 3.4% favoring SGA, p=0.001).

CONCLUSION

In patients with OHCA, we detected a slightly higher rate of CCF in patients for whom a SGA was inserted, both before and after insertion. However, the actual differences were so small, that in the context of this observational, secondary analysis, it is unclear if this represents a clinically significant difference.

Time on the scene and interventions are associated with improved survival in pediatric out-of-hospital cardiac arrest

BACKGROUND

Survival is less than 10% for pediatric patients following out-of-hospital cardiac arrest. It is not known if more time on the scene of the cardiac arrest and advanced life support interventions by emergency services personnel are associated with improved survival.

AIM

This study was performed to determine which times on the scene and which prehospital interventions were associated with improved survival.

METHODS

We studied patients aged 3 days to 19 years old with out-of-hospital cardiac arrest, using the Resuscitation Outcomes Consortium cardiac arrest database from 11 North American regions, from 2005 to 2012. We evaluated survival to hospital discharge according to on-scene times (<10, 10 to 35 and >35 min).

RESULTS

Data were available for 2244 patients (1017 infants, 594 children and 633 adolescents). Infants had the lowest rate of survival (3.7%) compared to children (9.8%) and adolescents (16.3%). Survival improved over the 7 year study period especially among adolescents. Survival was highest in the 10 to 35 min on-scene time group (10.2%) compared to the >35 min. group (6.9%) and the <10 min. group (5.3%, p=0.01). Intravenous or intra-osseous access attempts and fluid administration were associated with improved survival, whereas advanced airway attempts were not associated with survival and resuscitation drugs were associated with worse survival.

CONCLUSIONS

In this observational study, a scene time of 10 to 35 min was associated with the highest survival, especially among adolescents. Access for fluid resuscitation was associated with increased survival but advanced airway and resuscitation drugs were not.

Mechanisms linking advanced airway management and cardiac arrest outcomes

Advanced airway management--such as endotracheal intubation (ETI) or supraglottic airway (SGA) insertion--is one of the most prominent interventions in out-of-hospital cardiac arrest (OHCA) resuscitation. While randomized controlled trials are currently in progress to identify the best advanced airway technique in OHCA, the mechanisms by which airway management may influence OHCA outcomes remain unknown. We provide a conceptual model describing potential mechanisms linking advanced airway management with OHCA outcomes.

Volume versus outcome: More emergency medical services personnel on-scene and increased survival after out-of-hospital cardiac arrest

BACKGROUND AND AIM

The large regional variation in survival after treatment of out-of-hospital cardiac arrest (OHCA) is incompletely explained. Communities respond to OHCA with differing number of emergency medical services (EMS) personnel who respond to the scene. The effect of different numbers of EMS personnel on-scene upon outcomes is unclear. We sought to evaluate the association between number of EMS personnel on-scene and survival after OHCA.

METHODS

We performed a retrospective review of prospectively collected data on 16,122 EMS-treated OHCA events from December 1, 2005 to May 31, 2007 from a combined population over 21 million people residing in an area of over 33,000 square miles in Canada and the United States. Number of EMS personnel on-scene was defined as the number of EMS personnel who responded to the scene of OHCA within 15 min after 9-1-1 call receipt and prior to patient death or transport away from the scene. Associations with survival to hospital discharge were assessed by using generalized estimating equations to construct multivariable logistic regression models.

RESULTS

Compared to a reference number of EMS personnel on-scene of 5 or 6, 7 or 8 EMS personnel on-scene was associated with a higher rate of survival to hospital discharge, adjusted odds ratio [OR], 1.35 (95% CI: 1.05, 1.73). There was no significant difference in survival between 5 or 6 personnel on-scene versus fewer.

CONCLUSION

More EMS personnel on-scene within 15 min of 9-1-1 call was associated with improved survival of out-of-hospital cardiac arrest. It is unlikely that this finding was mediated solely by earlier CPR or earlier defibrillation.