Correction to: Serum magnesium, mortality and disease progression in chronic kidney disease

Following publication of the original article [1], we have been notified that the name of one author was spelled incorrectly as Georges N. Na khoul, when the correct spelling is Georges N. Nakhoul.

Modest rates and wide variation in timely access to repeat kidney transplantation in the United States

Success of transplantation is not limited to initial receipt of a donor organ. Many kidney transplant recipients experience graft loss following initial transplantation and the benefits of expedited placement on the waiting list and retransplantation extend to this population. Factors associated with access to repeat transplantation may be unique given experience with the transplant process and prior viability as a candidate. We examined the incidence, risk factors, secular changes, and center-level variation of preemptive relisting or transplantation (PRLT) for kidney transplant recipients in the United States with graft failure (not due to death) using Scientific Registry of Transplant Recipients data from 2007 to 2018 (n = 39 557). Overall incidence of PRLT was 15% and rates of relisting declined over time. Significantly lower PRLT was evident among patients who were African American and Hispanic, males, older, obese, publicly insured, had lower educational attainment, were diabetic, had longer dialysis time prior to initial transplant, shorter graft survival, longer distance to transplant center, and resided in distressed communities. There was significant variation in PRLT by center, median = 13%, 10th percentile = 6%, 90th percentile = 24%. Cumulatively, results indicate that despite prior access to transplantation, incidence of PRLT is modest with pronounced clinical, social, and center-level sources of variation suggesting opportunities to improve preemptive care among patients with failing grafts.

Serum magnesium, mortality and disease progression in chronic kidney disease

Introduction

Magnesium disorders are commonly encountered in chronic kidney disease (CKD) and are typically a consequence of decreased kidney function or frequently prescribed medications such as diuretics and proton pump inhibitors. While hypomagnesemia has been linked with increased mortality, the association between elevated magnesium levels and mortality is not clearly defined. Additionally, associations between magnesium disorders, type of death, and CKD progression have not been reported. Therefore, we studied the associations between magnesium levels, CKD progression, mortality, and cause specific deaths in patients with CKD.

Methods

Using the Cleveland Clinic CKD registry, we identified 10,568 patients with estimated Glomerular Filtration Rate (eGFR) between 15 and 59 ml/min/1.73 m² in this range for a minimum of 3 months with a measured magnesium level. We categorized subjects into 3 groups based on these magnesium levels (≤ 1.7, 1.7–2.6 and > 2.6 mg/dl) and applied cox regression modeling and competing risk models to identify associations with overall and cause-specific mortality. We also evaluated the association between magnesium level and slope of eGFR using mixed models.

Results

During a median follow-up of 3.7 years, 4656 (44%) patients died. After adjusting for relevant covariates, a magnesium level < 1.7 mg/dl (vs. 1.7–2.6 mg/dl) was associated with higher overall mortality (HR = 1.14, 95% CI: 1.04, 1.24), and with higher sub-distribution hazards for non-cardiovascular non-malignancy mortality (HR = 1.29, 95% CI: 1.12, 1.49). Magnesium levels > 2.6 mg/dl (vs. 1.7–2.6 mg/dl) was associated with a higher risk of all-cause death only (HR = 1.23, 95% CI: 1.03, 1.48). We found similar results when evaluating magnesium as a continuous measure. There were no significant differences in the slope of eGFR across all three magnesium groups (p = 0.10).

Conclusions

In patients with CKD stage 3 and 4, hypomagnesemia was associated with higher all-cause and non-cardiovascular non-malignancy mortality. Hypermagnesemia was associated with higher all-cause mortality. Neither hypo nor hypermagnesemia were associated with an increased risk of CKD progression.

Abstract TP318: The Hospital Level Variation in Interhospital Transfer in Ischemic Stroke

Background: Interhospital transfer of patients with stroke to higher level of care is a resource intensive practice. This study aimed to understand the patterns of interhospital transfer in the context of hospital characteristics.

Methods: This study included Medicare fee-for-service beneficiaries aged ≥65 years who were hospitalized in 2012 for ischemic stroke and underwent interhospital transfers. The data obtained from the American Hospital Association Annual Survey were linked to the 2012 Medicare inpatient and outpatient files. This study included patients admitted to the hospitals which were categorized as “general hospitals” with emergency departments. Hospitals were classified into receiving (high transfer in rate), sending (high transfer out rate), low flow (low transfer in or out rates), and high flow (both high transfer in and out) hospitals. Pearson’s chi-square tests were used for categorical variables and Wilcoxon Rank-Sum tests for continuous variables.

Results: Interhospital transfers for ischemic stroke occurred in 2876 out of 4198 hospitals (68.5%), and 5.7% of ischemic stroke admissions (19,283 of 338,306 admissions). Using national average of 5.7% as cut off, the four hospital groups : 411 receiving hospitals (14.3%), 559 sending hospitals (19.4%), 1863 low-flow hospitals (64.8%). Receiving hospitals were larger than low-flow and sending hospitals by the number of beds (Median 371, 189, and 88, respectively, p<0.001) and by annual stroke volume (median 205, 86, and 26, respectively, p<0.001). The majority of receiving (75%) and low-flow hospitals (54%) were in the Metropolitan area, while sending hospital were more evenly distributed in both urban and rural area. Higher proportion of teaching hospitals were in receiving hospitals(28%) compared to low-flow(6%) and sending hospitals (1%) with p<0.001. Higher proportion of receiving (75%) and low-flow (47%) hospitals were certified stroke centers, compared to sending hospitals (16%) with p<0.001.

Conclusions: The national patterns of interhospital transfer for ischemic stroke varies depending on the hospital size, geographical location, academic status, and stroke certification. Further study of the associated outcomes will aid in health care resource utilization.

Patterns and predictors of fatigue following living donor nephrectomy: Findings from the KDOC Study

This study sought to identify the prevalence, pattern, and predictors of clinical fatigue in 193 living kidney donors (LKDs) and 20 healthy controls (HCs) assessed at predonation and 1, 6, 12, and 24 months postdonation. Relative to HCs, LKDs had significantly higher fatigue severity (P = .01), interference (P = .03), frequency (P = .002), and intensity (P = .01), and lower vitality (P < .001), at 1-month postdonation. Using published criteria, significantly more LKDs experienced clinical fatigue at 1 month postdonation, compared to HCs, on both the Fatigue Symptom Inventory (60% vs. 37%, P < .001) and SF-36 Vitality scale (67% vs. 16%, P < .001). No differences in fatigue scores or clinical prevalence were observed at other time points. Nearly half (47%) reported persistent clinical fatigue from 1 to 6 months postdonation. Multivariable analyses demonstrated that LKDs presenting for evaluation with a history of affective disorder and low vitality, those with clinical mood disturbance and anxiety about future kidney failure after donation, and those with less physical activity engagement were at highest risk for persistent clinical fatigue 6 months postdonation. Findings confirm inclusion of fatigue risk in existing OPTN informed consent requirements, have important clinical implications in the care of LKDs, and underscore the need for further scientific examination in this population.

A Donor Utilization Index to Assess the Utilization and Discard of Deceased Donor Kidneys Perceived as High Risk

BACKGROUND AND OBJECTIVES

An increasing number of patients on the waitlist for a kidney transplant indicates a need to effectively utilize as many deceased donor kidneys as possible while ensuring acceptable outcomes. Assessing regional and center-level organ utilization with regards to discard can reveal regional variation in suboptimal deceased donor kidney acceptance patterns stemming from perceptions of risk.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We created a weighted donor utilization index from a logistic regression model using high-risk donor characteristics and discard rates from 113,640 deceased donor kidneys procured for transplant from 2010 to 2016, and used it to examine deceased donor kidney utilization in 182 adult transplant centers with >15 annual deceased donor kidney transplants. Linear regression and correlation were used to analyze differences in donor utilization indexes.

RESULTS

The donor utilization index was found to significantly vary by Organ Procurement and Transplantation Network region (P<0.001), revealing geographic trends in kidney utilization. When investigating reasons for this disparity, there was no significant correlation between center volume and donor utilization index, but the percentage of deceased donor kidneys imported from other regions was significantly associated with donor utilization for all centers (rho=0.39; P<0.001). This correlation was found to be particularly strong for region 4 (rho=0.83; P=0.001) and region 9 (rho=0.82; P=0.001). Additionally, 25th percentile time to transplant was weakly associated with the donor utilization index (R ²=0.15; P=0.03).

CONCLUSIONS

There is marked center-level variation in the use of deceased donor kidneys with less desirable characteristics both within and between regions. Broader utilization was significantly associated with shorter time to transplantation.

Evaluating Glomerular Filtration Rate Slope as a Surrogate End Point for ESKD in Clinical Trials: An Individual Participant Meta-Analysis of Observational Data

BACKGROUND

Decline in eGFR is a biologically plausible surrogate end point for the progression of CKD in clinical trials. However, it must first be tested to ensure strong associations with clinical outcomes in diverse populations, including patients with higher eGFR.

METHODS

To investigate the association between 1-, 2-, and 3-year changes in eGFR (slope) with clinical outcomes over the long term, we conducted a random effects meta-analysis of 3,758,551 participants with baseline eGFR≥60 ml/min per 1.73 m² and 122,664 participants with eGFR<60 ml/min per 1.73 m² from 14 cohorts followed for an average of 4.2 years.

RESULTS

Slower eGFR decline by 0.75 ml/min per 1.73 m² per year over 2 years was associated with lower risk of ESKD in participants with baseline eGFR≥60 ml/min per 1.73 m² (adjusted hazard ratio, 0.70; 95% CI, 0.68 to 0.72) and eGFR<60 ml/min per 1.73 m² (0.71; 95% CI, 0.68 to 0.74). The relationship was stronger with 3-year slope. For a rapidly progressing population with predicted 5-year risk of ESKD of 8.3%, an intervention that reduced eGFR decline by 0.75 ml/min per 1.73 m² per year over 2 years would reduce the ESKD risk by 1.6%. For a hypothetical low-risk population with a predicted 5-year ESKD risk of 0.58%, the same intervention would reduce the risk by only 0.13%.

CONCLUSIONS

Slower decline in eGFR was associated with lower risk of subsequent ESKD, even in participants with eGFR≥60 ml/min per 1.73 m², but those with the highest risk would be expected to benefit the most.

Time for reform in transplant program-specific reporting: AST/ASTS transplant metrics taskforce

In accordance with the National Organ Transplant Act and Department of Health and Human Services' Final Rule, the Scientific Registry of Transplant Recipients (SRTR) publicly releases biannual program-specific reports that include analyses of transplant centers' risk-adjusted waitlist mortality, organ acceptance ratios, transplant rates, and graft and patient survival. Since the inception of these center metrics, 1-year posttransplant graft and patient survival have improved, and center variation has decreased, casting uncertainty on their clinical relevance. The SRTR has recently modified center evaluations by ranking centers into 5 tiers rather than 3 tiers in an attempt to discriminate between programs performing within a tight range, further exacerbating this uncertainty. The American Society of Transplantation/American Society of Transplant Surgeons convened an expert taskforce to examine both the utility and unintended consequences of transplant center metrics. Estimates of center variation in outcomes in adjacent tiers are imprecise and fleeting, but can result in consequential changes in clinician and center behavior. The taskforce has concerns that current metrics, based principally on 1-year graft and patient survival, provide minimal if any benefit in informing patient choice and access to transplantation, with the untoward effect of decreased utilization of organs and restriction of research and innovation.

Elevated Risk of Split-Liver grafts in adult liver Transplantation: Statistical Artifact or Nature of the Beast?

A recent study using US national registry data reported, using Cox proportional hazards (PH) models, that split-liver transplantation (SLT) has improved over time and is no more hazardous than whole-liver transplantation (WLT). However, the study methods violated the PH assumption, which is the fundamental assumption of Cox modeling. As a result, the reported hazard ratios (HRs) are biased and unreliable. This study aimed to investigate whether the risk of graft survival (GS) in SLT has really improved over time, ensuring attention to the PH assumption. This study included 80,998 adult deceased donor liver transplantation (LT) (1998-2015) from the Scientific Registry Transplant Recipient. The study period was divided into 3 time periods: era 1 (January 1998 to February 2002), era 2 (March 2002 to December 2008), and era 3 (January 2009 to December 2015). The PH assumption was tested using Schoenfeld's test, and where the HR of SLT violated the assumption, changes in risk for SLT over time from transplant were assessed. SLT was performed in 1098 (1.4%) patients, whereas WLT was used in 79,900 patients. In the Cox PH analysis, the P values of Schoenfeld's global tests were <0.05 in all eras, which is consistent with deviation from proportionality. Assessing HRs of SLT with a time-varying effect, multiple Cox models were conducted for post-LT intervals. The HR curves plotted according to time from transplant were higher in the early period and then decreased at approximately 1 year and continued to decrease in all eras. For 1-year GS, the HRs of SLT were 1.92 in era 1, 1.52 in era 2, and 1.47 in era 3 (all P < 0.05). In conclusion, the risk of SLT has a time-varying effect and is highest in the early post-LT period. The risk of SLT is underestimated if it is evaluated by overall GS. SLT was still hazardous if the PH assumption was considered, although it became safer over time.

Diagnostic Performance of Blood Pressure Measurement Modalities in Living Kidney Donor Candidates

BACKGROUND AND OBJECTIVES

Precise BP measurement to exclude hypertension is critical in evaluating potential living kidney donors. Ambulatory BP monitoring is considered the gold standard method for diagnosing hypertension, but it is cumbersome to perform. We sought to determine whether lower BP cutoffs using office and automated BP would reduce the rate of missed hypertension in potential living donors.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We measured BP in 578 prospective donors using three modalities: (1) single office BP, (2) office automated BP (average of five consecutive automated readings separated by 1 minute), and (3) ambulatory BP. Daytime ambulatory BP was considered the gold standard for diagnosing hypertension. We assessed both the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) and the American College of Cardiology/American Heart Association (ACC/AHA) definitions of hypertension in the cohort. Empirical thresholds of office BP and automated BP for the detection of ambulatory BP-diagnosed hypertension were derived using Youden index, which maximizes the sum of sensitivity and specificity and gives equal weight to false positive and false negative values.

RESULTS

Hypertension was diagnosed in 90 (16%) prospective donors by JNC-7 criteria and 198 (34%) prospective donors by ACC/AHA criteria. Masked hypertension was found in 3% of the total cohort by JNC-7 using the combination of office or automated BP, and it was seen in 24% by ACC/AHA guidelines. Using Youden index, cutoffs were derived for both office and automated BP using JNC-7 (<123/82 and <120/78 mm Hg) and ACC/AHA (<119/79 and <116/76 mm Hg) definitions. Using these lower cutoffs, the sensitivity for detecting hypertension improved from 79% to 87% for JNC-7 and from 32% to 87% by ACC/AHA definition, with negative predictive values of 95% and 87%, respectively. Missed (masked) hypertension was reduced to 2% and 4% of the entire cohort by JNC-7and ACC/AHA, respectively.

CONCLUSIONS

The prevalence of hypertension was higher in living donor candidates using ACC/AHA compared JNC-7 definitions. Lower BP cutoffs in the clinic improved sensitivity and led to a low overall prevalence of missed hypertension in prospective living kidney donors.

Abstract 147: The Trend of In-hospital Complications During Acute Ischemic Stroke Hospitalization Among US Elderly

Background: Stroke is the fifth leading cause of death in the United States and the leading cause of long-term disability in adult. Many efforts have been devoted to improve the stroke quality of care. We aimed to examine the recent rate and trend of in-hospital complications among U.S. elderly who were hospitalized for acute ischemic stroke from 2009 to 2013.

Methods: We examined the prevalence and trend of in-hospital pneumonia, urinary tract infection (UTI), deep vein thrombosis (DVT) and pulmonary embolization (PE) among Medicare beneficiaries aged 65 years and older who were hospitalized between January 2009 and December 2013 with a primary discharge diagnosis of acute ischemic stroke. The data of patient information were obtained from the Medicare Provider Analysis and Review file. The in-hospital complications were identified using the ICD-9 CM codes that have been previously validated.

Results: A total of 1,070,574 Medicare beneficiaries were hospitalized for ischemic stroke between 2009 and 2013. The in-hospital pneumonia decreased from 17507 (7.7%) in 2009 to 14078 (6.8%) in 2013, an 11.7% decrease. The in-hospital UTI decreased from 34356 (15%) in 2009 to 29134 (14.1%) in 2013, a 6% decrease. The in-hospital DVT increased from 2263 (1.0%) in 2009 to 2605 (1.3%), a 30% increase. The in-hospital PE increased from 754 (0.3%) in 2009 to 800 (0.4%) in 2013, a 33% increase.

Conclusion: Among Medicare beneficiaries who were hospitalized for acute ischemic stroke from 2009 to 2013, the prevalence of in-hospital pneumonia and UTI decreased while DVT and PE dramatically increased. These results call for further interventions to prevent in-hospital thrombotic complications.

Characteristics and Outcomes of Patients With Aortic Stenosis and Chronic Kidney Disease

Background We sought to study longer term survival in patients with aortic stenosis ( AS ) and nondialysis chronic kidney disease ( CKD ). Methods and Results We studied 839 patients (aged 78±9 years and 51% male) with CKD and AS on echocardiogram from 2005 to 2012. Longer term all-cause and cardiovascular mortality was compared with a CKD group without AS , propensity matched for age, sex, race, left ventricular ejection fraction and CKD stage. Cox models were used to evaluate all-cause mortality and competing-risks regression models censored at time of aortic valve replacement to evaluate cardiac mortality in patients with AS and CKD . Overall, 511 (61%), 252 (30%), and 76 (9%) patients had CKD stages 3a, 3b, and 4, respectively; 93% had hypertension, 28% had diabetes mellitus, and 37% had coronary artery disease. In total, 185 (22%) had mild AS, 355 (42%) had moderate AS, and 299 (36%) had severe AS (66 symptomatic). Patients with CKD and AS had higher cardiac and all-cause mortality compared with controls with CKD and no AS ( P<0.001). Among patients with AS and CKD , there were 156 (19%) aortic valve replacements and 454 (54%) deaths (203 cardiac deaths) at 4.0±2.3 years of follow-up. Lower estimated glomerular filtration rate (hazard ratio per 10 mL/min per 1.73 m2: 1.18; 95% CI, 1.08-1.29) was associated with increased risk of all-cause mortality but not cardiac mortality (hazard ratio: 1.12; 95% CI, 0.97-1.30; P=0.13). Of patients undergoing aortic valve replacement, 61% had improvement in estimated glomerular filtration rate within 1 year (median percentage change=+2.8% per month). Conclusions Among patients with nondialysis CKD , AS is associated with significantly higher cardiac and all-cause mortality; lower estimated glomerular filtration rate is associated with increased mortality, and aortic valve replacement was associated with improved survival.

Dramatic secular changes in prognosis for kidney transplant candidates in the United States

Over recent decades, numerous clinical advances and policy changes have affected outcomes for candidates of kidney transplantation in the United States. We examined the national Scientific Registry for Transplant Recipients for adult (18+) solitary kidney transplant candidates placed on the waiting list for primary listing from 2001 to 2015. We evaluated rates of mortality, transplantation, and waitlist removal. Among 340 115 candidates there were significant declines in mortality (52 deaths/1000 patient years in 2001-04 vs 38 deaths/1000 patient years in 2012-15) and transplant rates (304 transplants/1000 patient years in 2001-04 vs 212 transplants/1000 patient years in 2012-15) and increases in waitlist removals (15 removals/1000 patient years in 2001-04 vs 25/1000 patient years in 2012-15) within the first year after listing. At 5 years an estimated 37% of candidates listed in 2012-15 were alive without transplant as compared to 22% in 2001-04. Declines in mortality over time were significantly more pronounced among African Americans, candidates with longer dialysis duration, and those with diabetes (P < .001). Cumulatively, results indicate dramatic changes in prognoses for adult kidney transplant candidates, likely impacted by selection criteria, donor availability, regulatory oversight, and clinical care. These trends are important considerations for prospective policy development and research, clinical and patient decision-making, and evaluating the impact on access to care.

Ureteral Wall Injury with Ureteral Access Sheaths: A Randomized Prospective Trial

Objective: To compare two commercially available ureteral access sheaths in their ability to access the renal collecting system and assess ureteral wall trauma using a prospective, randomized trial. Patients and Methods: Ninety-five patients undergoing ureteroscopy for renal stones were randomized to Cook Flexor™ or Boston Scientific Navigator HD™ 12/14F sheaths. If the initial sheath failed to advance, an alternate sheath was attempted. The primary outcome was the difference in these access sheaths to obtain access to the upper collecting system and the postoperative ureteral injury using standardized five-point classification system. Results: The overall success rate for sheath placement was 87.4% and did not differ for sheath groups. The Navigator HD was successful in 43% of the Flexor failures and was subjectively rated as easier to place (p = 0.018). Male gender, large stone burden, longer time of sheath insertion, and a more difficult subjective rating for sheath placement were associated with high-grade (grade 2 or 3) ureteral injury. Limitations include a small sample size and absence of long-term follow-up. Conclusion: Sheaths had equal success of placement and there was no significant difference in ureteral wall injury between the two sheaths. Subjectively difficult sheath placement and longer time of placement were associated with high-grade injury, suggesting that surgeons should carry a low threshold for switching to a smaller sheath when resistance is felt or if placement time is long. Clinical Trial number: Nct03349099.

What are the Risk Factors for One-Year Mortality in Older Patients with Chronic Kidney Disease? An Analysis of the Cleveland Clinic CKD Registry

BACKGROUND

Prognostic factors after dialysis initiation among older chronic kidney disease (CKD) patients are not well studied. In this study, we examined the risk factors associated with 1-year mortality after dialysis initiation among older CKD patients.

METHODS

In this retrospective study, we included 621 CKD patients from an electronic medical record based CKD registry that was linked to the United States Renal Data System data. In terms of age, they were all ≥65. We examined the associations of various demographic factors, comorbid conditions, relevant laboratory parameters, the presence of arteriovenous fistula, and inability to take care of oneself with 1-year mortality after dialysis initiation using Cox proportional hazards model.

RESULTS

In our study cohort, 224 older patients died during the first year of dialysis initiation and the estimated survival at 1 year was 65% (95% CI 62-69). After adjusting for covariates, increasing age by each year (Hazard ratio 1.04 [95% CI 1.02-1.06]), congestive heart failure (CHF; 1.57 [1.13-2.18]), an absence of AVF (3.0 [1.7-5.1]) and lack of nephrology care prior to dialysis initiation (1.93 [1.39-2.70]) were associated with increased risk of 1-year mortality. Nearly 60% of deaths were due to non-cardiovascular (CV) causes including cancer.

CONCLUSION

Risk factors portending high 1-year mortality in older CKD patients are increasing age, CHF, an absence of AVF, and lack of pre-dialysis nephrology care. Clinicians need to be aware of non-CV risks of high mortality in these patients.

Fructose increases risk for kidney stones: potential role in metabolic syndrome and heat stress

Background

Fructose intake, mainly as table sugar or high fructose corn syrup, has increased in recent decades and is associated with increased risk for kidney stones. We hypothesized that fructose intake alters serum and urinary components involved in stone formation.

Methods

We analyzed a previously published randomized controlled study that included 33 healthy male adults (40–65 years of age) who ingested 200 g of fructose (supplied in a 2-L volume of 10% fructose in water) daily for 2 weeks. Participants were evaluated at the Unit of Nephrology of the Mateo Orfila Hospital in Menorca. Changes in serum levels of magnesium, calcium, uric acid, phosphorus, vitamin D, and intact PTH levels were evaluated. Urine magnesium, calcium, uric acid, phosphorus, citrate, oxalate, sodium, potassium, as well as urinary pH, were measured.

Results

Ingestion of fructose was associated with an increased serum level of uric acid (p < 0.001), a decrease in serum ionized calcium (p = 0.003) with a mild increase in PTH (p < 0.05) and a drop in urinary pH (p = 0.02), an increase in urine oxalate (p = 0.016) and decrease in urinary magnesium (p = 0.003).

Conclusions

Fructose appears to increase urinary stone formation in part via effects on urate metabolism and urinary pH, and also via effects on oxalate. Fructose may be a contributing factor for the development of kidney stones in subjects with metabolic syndrome and those suffering from heat stress.

Trial registration

ClinicalTrials.gov NCT00639756 March 20, 2008.

Patients prioritize waitlist over posttransplant outcomes when evaluating kidney transplant centers

Factors that patients value when choosing a transplant center have not been well studied. In order to guide the improvement of patient-facing materials, we conducted an anonymous electronic survey of patients that assessed the relative importance of patient experience, practical considerations, transplant center reputation, center experience, and waitlist when selecting a transplant center. A total of 409 respondents completed the survey, of whom 68% were kidney transplant recipients and 32% had chronic kidney disease or were on dialysis. Participants had mean age 56 ± 12 years and were predominantly female (61%), white (79%), and had an associate's degree or higher (68%). Participants most often prioritized waitlist when evaluating transplant centers (transplanted 26%, chronic kidney disease 40%), and waitlist was almost twice as likely as outcomes to be ranked most important (30% vs 17%). Education level and transplant status were significantly associated with factors used for center prioritization. Waitlisted respondents most commonly (48%) relied on physicians for information when selecting a center, while a minority cited transplant-specific organizations. In order to improve shared decision-making, materials outlining center-specific waitlist features should be prioritized. Novel patient-oriented metrics for measuring transplant center quality that align with patient priorities must be explored.

Intra-Arterial versus Intravenous Contrast and Renal Injury in Chronic Kidney Disease: A Propensity-Matched Analysis

BACKGROUND/AIMS

contrast-induced nephropathy (CIN) is well described following an administration of intraarterial contrast, but its occurrence after intravenous (IV) contrast is being questioned. We evaluated the incidence of acute kidney injury (AKI), post-contrast AKI (PC-AKI), CIN, dialysis and mortality in patients with chronic kidney disease (CKD) undergoing non-contrast computed tomography (NCCT) or contrast CT (CCT) or coronary angiography (CoA).

METHODS

We identified individuals who had CoA or CCT or NCCT between 2010 and 2015 in the Cleveland Clinic CKD registry. We used propensity scores to match patients in the 3 groups. We evaluated the proportion of patients that developed AKI and CIN across the groups with chi-square tests. We generated Kaplan-Meier plots comparing mortality and ESRD among patients who developed AKI (in the NCCT group), PC (multifactorial AKI, CIN) AKI and no AKI.

RESULTS

Out of 251 eligible patients, 200 who had CoA were matched to each of the other CT scan groups. The incidence of AKI was 27% in CoA, 24% in CCT and 24% in NCCT (p = 0.72). The incidence of CIN AKI was 16.5% in CoA and 12.5% in CCT (p = 0.26). The Kaplan-Meier survival at 2 years was 74.8 (95% CI 63.8-87.7) for those with CIN and 53.2 (95% CI 39.7-71.4) for those with multifactorial AKI and 56.5 (95% CI 43.4-73.6) for those with AKI-NCCT and 71.4 (95% CI 67.2-76.0) for those without AKI. The Kaplan-Meier ESRD-free estimates at 2 years were 89.9 (95% CI 80.8-100) for those with CIN and 89.4 (95% CI 78.7-100) for those with multifactorial AKI and 77.4 (95% CI 63.6-94.3) for those with AKI-NCCT and 94.4 (95% CI 91.9-97.1) for those without AKI.

CONCLUSION

The administration of both IV and intra-arterial contrast is associated with a risk of AKI. Multifactorial AKI was associated with worse outcomes, while CIN was associated with better outcomes.

Significantly Lower Rates of Kidney Transplantation among Candidates Listed with the Veterans Administration: A National and Local Comparison

BACKGROUND

The process for evaluating kidney transplant candidates and applicable centers is distinct for patients with Veterans Administration (VA) coverage. We compared transplant rates between candidates on the kidney waiting list with VA coverage and those with other primary insurance.

METHODS

Using the Scientific Registry of Transplant Recipients database, we obtained data for all adult patients in the United States listed for a primary solitary kidney transplant between January 2004 and August 2016. Of 302,457 patients analyzed, 3663 had VA primary insurance coverage.

RESULTS

VA patients had a much greater median distance to their transplant center than those with other insurance had (282 versus 22 miles). In an adjusted Cox model, compared with private pay and Medicare patients, VA patients had a hazard ratio (95% confidence interval) for time to transplant of 0.72 (0.68 to 0.76) and 0.85 (0.81 to 0.90), respectively, and lower rates for living and deceased donor transplants. In a model comparing VA transplant rates with rates from four local non-VA competing centers in the same donor service areas, lower transplant rates for VA patients than for privately insured patients persisted (hazard ratio, 0.72; 95% confidence interval, 0.65 to 0.79) despite similar adjusted mortality rates. Transplant rates for VA patients were similar to those of Medicare patients locally, although Medicare patients were more likely to die or be delisted after waitlist placement.

CONCLUSIONS

After successful listing, VA kidney transplant candidates appear to have persistent barriers to transplant. Further contemporary analyses are needed to account for variables that contribute to such differential transplant rates.

Cause-Specific Mortality in Patients with Chronic Kidney Disease and Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is associated with death in patients with chronic kidney disease (CKD). We examined the associations between AF and cause-specific mortality in a large CKD population.

METHODS

We included 62,459 patients with estimated glomerular filtration rate 15-59 mL/min/1.73 m2 (6,639 patients with AF and 55,820 without AF) followed in a large health care system. Outcomes included overall and cause-specific deaths (a) cardiovascular; (b) malignancy; and (c) non-cardiovascular/non-malignancy causes. Cox regression models for overall mortality and separate competing risk models for each major cause of death category were used to evaluate their respective associations with AF.

RESULTS

During a median follow-up of 4.1 years, 19,094 patients died; cause of death was known for 18,854 patients. After multivariable adjustment (demographics, comorbidities, relevant laboratory data, medication use, and kidney function), AF was associated with 23% (95% CI 18-29%) higher risk of all-cause mortality, 45% (95% CI 31-61%) higher risk of cardiovascular mortality and 13% (95% CI 3-22%) lower risk of malignancy-related mortality. Exclusion of patients with malignancy yielded similar results except for a lack of association between AF and malignancy-related deaths. Results were consistent across various stages of CKD.

CONCLUSIONS

In a non-dialysis-dependent CKD population, the presence of AF was associated with higher all-cause and cardiovascular mortality. These data suggest that patients with both CKD and AF are at high cardiovascular risk, and thus clinical practice (or trials) should aim at reducing the overall excess cardiovascular mortality (not stroke alone) in patients with AF and CKD.

The Association Between Lung Recipient Travel Distance and Posttransplant Survival

Introduction:

Recipient travel distance may be an unrecognized burden in lung transplantation.

Design:

Retrospective single-center cohort study of all adult (≥18 years) first-time lung-only transplants from January 1, 2010, until February 28, 2017. Recipient distance to transplant center was calculated using the linear distance from the recipient’s home zip code to the Cleveland Clinic in Cleveland, Ohio.

Results:

569 recipients met inclusion criteria. Posttransplant graft survival was 85%, 88%, 91%, and 91% at 1 year and 49%, 52%, 57%, and 56% at 5 years posttransplant for recipient travel distances of ≤50, >50 to ≤250, >250 to ≤500, and >500 miles, respectively ( P = .10).

Discussion:

We found no significant relationship between recipient travel distance and posttransplant graft survival. In carefully selected recipients, travel distance is not a significant barrier to successful posttransplant outcomes which may be important for patient decision-making and donor allocation policy. These data should be validated in a national cohort.