Impact of Uric Acid Levels on Kidney Disease Progression

BACKGROUND

Hyperuricemia is associated with the progression of chronic kidney disease (CKD), but it is not known whether the relationship is causal. We examined the association of hyperuricemia and uric acid lowering therapy (UALT) with progression of CKD in patients with CKD 3 and 4 in the Cleveland Clinic CKD registry.

METHODS

We included 1,676 patients with CKD stages 3 and 4 from Ohio, who had measured their uric acid (UA) levels a year prior to the recording of the second eGFR <60 mL/min/1.73 m2, and follow-up eGFR, between 2005 and 2009. Our primary composite outcome included a 50% drop in eGFR or progression to ESRD. Secondary outcomes included the rate of decline in eGFR, all-cause mortality, progression to ESRD, and a composite measure of progression to ESRD or death. We assessed the association between UA, UALT, and outcomes using Cox models and competing risks regression models.

RESULTS

In multivariable models, higher UA was associated with the composite endpoint, but it reached statistical significance only in the 4th quartile (≥8.9 mg/dL). Receipt of UALT was significantly associated with increased risk of the composite outcome. Neither UA nor UALT (considered a time-dependent covariate) was significantly associated with mortality. The inference was similar for UA as high vs. low, quartiles, or continuous. Similarly, neither high UA nor UALT were significantly associated with ESRD, the composite of ESRD and mortality, or eGFR decline.

CONCLUSIONS

Hyperuricemia is associated with increased risk of progression to ESRD in patients with CKD stages 3 and 4, but UALT does not ameliorate the risk, suggesting that the relationship is not causal.

Import kidney transplants from nonmandatory share deceased donors: characteristics, distribution and outcomes

Outcomes of locally rejected kidneys transplanted at other centers (import KTX) are unknown. SRTR data from 2000 to 2009 of deceased-donor KTXs excluding 0-mismatch, paybacks, and other mandatory shares were compared by location of KTX at local (n = 48,165), regional (n = 4428) or national (n = 4104) centers using multivariable regression models. Compared to nonmandatory share local transplants, import KTX were associated with significantly higher overall risks of patient death (regional aHR 1.15, p < 0.01; national aHR 1.14, p < 0.01), and graft failure (regional aHR 1.17, p < 0.01; national aHR1.21, p < 0.01). In paired analysis, the risk of delayed graft function (DGF) for import KTX was higher compared to locally transplanted mates (regional aOR 1.53, p < 0.01, national aOR 2.14, p < 0.01); however, despite longer ischemia times, overall graft survival was similar. Mean cold ischemia times (CIT) pre- and post-DonorNet were similar for local and regional transplants, but significantly higher for national transplants (28.9 ± 9.9 vs. 29.9 ± 9.7 h, respectively, p = 0.01). Import KTX is associated with increased risks of graft failure, patient death and DGF. In the era of DonorNet cold ischemia times of kidneys imported to regional centers are not improved compared to pre-DonorNet; and, those of national centers are significantly prolonged.

Recovery factors affecting utilization of small pediatric donor kidneys

Kidneys from small pediatric donors are underutilized. Using data from the Scientific Registry of Transplant Recipients for donors <21 kg in which at least one organ was recovered from 1997 to 2007 (n = 3341), donor and recovery factors were evaluated by multivariate analysis for associations with (a) kidney nonrecovery and (b) transplantation of recovered kidneys.

RESULTS

The proportion of kidney recoveries were 55% during liver procurements and 40% during intestine procurements amongst donors <10 kg (p < 0.01) compared to 93% and 88%, respectively, for donors weighing 10-20 kg (p = 0.003). Intestine procurement was independently associated with an 81% greater likelihood of kidney nonrecovery (p < 0.0001) and a 48% lower likelihood of transplantation (p = 0.0004). A multivariate Cox model indicated that single kidney recipients had a 63% higher risk of graft failure compared with en bloc kidney recipients (p < 0.0001); however, concurrent intestine recovery was not a significant risk factor for graft loss. Intestine recovery from donors <21 kg of age is strongly associated with higher kidney nonrecovery and lower transplantation rates. Graft survival is worse with single kidney transplantation, but is not significantly affected by intestine recovery. Small pediatric donors procurement teams should strive to increase kidney recoveries overall and en bloc recoveries in particular.

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.

Readiness of wait-listed black patients to pursue live donor kidney transplant

CONTEXT

For adults with end-stage kidney disease, live donor kidney transplant (LDKT) has better outcomes than long-term dialysis and deceased donor kidney transplant. However, black patients receive LDKT at a much lower rate than adults of any other race or ethnicity.

OBJECTIVE

To examine the LDKT readiness stage of black patients on the transplant waiting list and its association with LDKT knowledge, concerns, and willingness.

DESIGN

Cross-sectional analysis of baseline data from a randomized controlled trial to improve knowledge and reduce concerns about LDKT.Patients and Setting-One hundred fifty-two black patients on the kidney transplant waiting list at a single transplant center in the northeastern United States.

MAIN OUTCOME MEASURES

LDKT readiness stage, knowledge, concerns, and willingness to talk to others about living donation.

RESULTS

Sixty percent of patients were not considering or not yet ready to pursue LDKT, and only 11% had taken action to talk to family members or friends about the possibility of living kidney donation. Patients in later stages of LDKT readiness (ie, who had talked to others about donation or were preparing to do so) had significantly more knowledge (P<.001), fewer concerns (P=.002), and more willingness (P=.001) to talk to others about living donation than those in earlier readiness stages.

CONCLUSIONS

The large percentage of black patients who are in the earlier stages of LDKT readiness may account for the low rate of LDKT in this patient population at our transplant center. Innovative and tailored LDKT educational strategies for black patients are needed to help reduce racial disparities in LDKT.

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.

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.

Addressing sex-based disparities in solid organ transplantation in the United States - a conference report

Solid organ transplantation provides the best treatment for end-stage organ failure, but significant sex-based disparities in transplant access exist. On June 25, 2021, a virtual multidisciplinary conference was convened to address sex-based disparities in transplantation. Common themes contributing to sex-based disparities were noted across kidney, liver, heart, and lung transplantation, specifically the existence of barriers to referral and wait listing for women, the pitfalls of using serum creatinine, the issue of donor/recipient size mismatch, approaches to frailty and a higher prevalence of allosensitization among women. In addition, actionable solutions to improve access to transplantation were identified, including alterations to the current allocation system, surgical interventions on donor organs, and the incorporation of objective frailty metrics into the evaluation process. Key knowledge gaps and high-priority areas for future investigation were also discussed.

COVID-19 mortality among kidney transplant candidates is strongly associated with social determinants of health

The COVID-19 pandemic has affected all portions of the global population. However, many factors have been shown to be particularly associated with COVID-19 mortality including demographic characteristics, behavior, comorbidities, and social conditions. Kidney transplant candidates may be particularly vulnerable to COVID-19 as many are dialysis-dependent and have comorbid conditions. We examined factors associated with COVID-19 mortality among kidney transplant candidates from the National Scientific Registry of Transplant Recipients from March 1 to December 1, 2020. We evaluated crude rates and multivariable incident rate ratios (IRR) of COVID-19 mortality. There were 131 659 candidates during the study period with 3534 all-cause deaths and 384 denoted a COVID-19 cause (5.00/1000 person years). Factors associated with increased COVID-19 mortality included increased age, males, higher body mass index, and diabetes. In addition, Blacks (IRR = 1.96, 95% C.I.: 1.43-2.69) and Hispanics (IRR = 3.38, 95% C.I.: 2.46-4.66) had higher COVID-19 mortality relative to Whites. Patients with lower educational attainment, high school or less (IRR = 1.93, 95% C.I.: 1.19-3.12, relative to post-graduate), Medicaid insurance (IRR = 1.73, 95% C.I.: 1.26-2.39, relative to private), residence in most distressed neighborhoods (fifth quintile IRR = 1.93, 95% C.I.: 1.28-2.90, relative to first quintile), and most urban and most rural had higher adjusted rates of COVID-19 mortality. Among kidney transplant candidates in the United States, social determinants of health in addition to demographic and clinical factors are significantly associated with COVID-19 mortality.

Expanding clarity or confusion? Volatility of the 5-tier ratings assessing quality of transplant centers in the United States

Outcomes of patients receiving solid organ transplants in the United States are systematically aggregated into bi-annual Program-Specific Reports (PSRs) detailing risk-adjusted survival by transplant center. Recently, the Scientific Registry of Transplant Recipients (SRTR) issued 5-tier ratings evaluating centers based on risk-adjusted 1-year graft survival. Our primary aim was to examine the reliability of 5-tier ratings over time. Using 10 consecutive PSRs for adult kidney transplant centers from June 2012 to December 2016 (n = 208), we applied 5-tier ratings to center outcomes and evaluated ratings over time. From the baseline period (June 2012), 47% of centers had at least a 1-unit tier change within 6 months, 66% by 1 year, and 94% by 3 years. Similarly, 46% of centers had at least a 2-unit tier change by 3 years. In comparison, 15% of centers had a change in the traditional 3-tier rating at 3 years. The 5-tier ratings at 4 years had minimal association with baseline rating (Kappa 0.07, 95% confidence interval [CI] -0.002 to 0.158). Centers had a median of 3 different 5-tier ratings over the period (q1 = 2, q3 = 4). Findings were consistent for center volume, transplant rate, and baseline 5-tier rating. Cumulatively, results suggest that 5-tier ratings are highly volatile, limiting their utility for informing potential stakeholders, particularly transplant candidates given expected waiting times between wait listing and transplantation.

A tool for decision-making in kidney transplant candidates with poor prognosis to receive deceased donor transplantation in the United States

The primary outcomes for kidney transplant candidates are receipt of deceased or living donor transplant, death or removal from the waiting list. Here, we conducted a retrospective analysis of national Scientific Registry of Transplant Recipients data to evaluate outcomes for 208,717 adult kidney transplant candidates following the 2014 Kidney Allocation System in the United States. Competing risks models were utilized to evaluate Time to Equivalent Risk (TiTER) of deceased donor transplantation (DDTX) and death versus waitlist removal. We also evaluated TiTER based on kidney donor profile index (KDPI) and donor age. For all groups, the cumulative incidence of DDTX was initially higher from time of listing than death or waitlist removal. However, following accrued time on the waiting list, the cumulative incidence of death or waitlist removal exceeded DDTX for certain patient groups, particularly older, diabetic, blood type B and O and shorter pre-listing dialysis time. TiTER for all candidates aged 65-69 averaged 41 months and for 70 and older patients 28 months. Overall, 39.6% of candidates were in risk groups with TiTER under 72 months and 18.5% in groups with TiTER under 24 months. Particularly for older candidates, TiTER for kidneys was substantially shorter for younger donors or lower KDPI. Thus, our findings reveal that a large proportion of waitlisted patients in the United States have poor prognoses to ever undergo DDTX and our data may improve shared decision-making for candidates at time of waitlist placement. Hence, for specific patient groups, TiTER may be a useful tool to disseminate and quantify benefits of accepting relatively high risk donor organs.

Residential Area Life Expectancy: Association With Outcomes and Processes of Care for Patients With ESRD in the United States

BACKGROUND

The effects of underlying noncodified risks are unclear on the prognosis of patients with end-stage renal disease (ESRD). We aimed to evaluate the association of residential area life expectancy with outcomes and processes of care for patients with ESRD in the United States.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adult patients with incident ESRD between 2006 and 2013 recorded in the US Renal Data System (n=606,046).

PREDICTOR

The primary exposure was life expectancy in the patient's residential county estimated by the Institute for Health Metrics and Evaluation.

OUTCOMES

Death, placement on the kidney transplant wait list, living and deceased donor kidney transplantation, and posttransplantation graft loss.

RESULTS

Median life expectancies of patients' residences were 75.6 (males) and 80.4 years (females). Compared to the highest life expectancy quintile and adjusted for demographic factors, disease cause, and multiple comorbid conditions, the lowest quintile had adjusted HRs for mortality of 1.20 (95% CI, 1.18-1.22); placement onto the waiting list, 0.68 (95% CI, 0.67-0.70); living donor transplantation, 0.53 (95% CI, 0.51-0.56); posttransplantation graft loss, 1.35 (95% CI, 1.27-1.43); and posttransplantation mortality, 1.29 (95% CI, 1.19-1.39). Patients living in areas with lower life expectancy were less likely to be informed about transplantation, be under the care of a nephrologist, or receive an arteriovenous fistula as the initial dialysis access. Results remained consistent with additional adjustment for zip code-level median income, population size, and urban-rural locality.

LIMITATIONS

Potential residual confounding and attribution of effects to individuals based on residential area-level data.

CONCLUSIONS

Residential area life expectancy, a proxy for socioeconomic, environmental, genetic, and behavioral factors, was independently associated with mortality and process-of-care measures for patients with ESRD. These results emphasize the underlying effect on health outcomes of the environment in which patients live, independent of patient-level factors. These findings may have implications for provider assessments.

Association Between Donor-Recipient Biological Relationship and Allograft Outcomes After Living Donor Kidney Transplant

IMPORTANCE

The proportion of living donor kidney transplants from donors unrelated to their recipients is increasing in the US.

OBJECTIVE

To examine the association between donor-recipient biological relationship and allograft survival after living donor kidney transplant.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used Organ Procurement and Transplantation Network data on US adult living donor kidney transplants (n = 86 154) performed from January 1, 2000, to December 31, 2014, excluding cases in which recipients previously received a kidney transplant (n = 10 342) or key data were missing (n = 2832). Last follow-up was March 20, 2020.

EXPOSURES

Donor-recipient biological relationship.

MAIN OUTCOMES AND MEASURES

The primary outcome was death-censored allograft failure. Univariate and multivariable time-to-event analyses were performed for death-censored allograft failure for the overall cohort, then separately for recipients with and without primary diagnoses of cystic kidney disease and for transplants from African American and non-African American donors.

RESULTS

Among the 72 980 transplant donor and recipients included in the study (median donor age, 41 years; interquartile range [IQR], 32-50 years; 43 990 [60%] female; 50 014 [69%] White), 43 174 (59%) donors and recipients were biologically related and 29 806 (41%) were unrelated. Donors related to their recipients were younger (median [IQR] age, 39 [31-48] vs 44 [35-52] years) and less likely to be female (24 848 [58%] vs 19 142 [64%]) or White (26 933 [62%] vs 23 081 [77%]). Recipients related to their donors were younger (median [IQR] age, 48 [34-58] vs 50 [40-58] years), more likely to be female (18 035 [42%] vs 10 530 [35%]), and less likely to have cystic kidney disease (2530 [6%] vs 4600 [15%]). Related pairs had fewer HLA mismatches overall (median [IQR], 3 [2-3] vs 5 [4-5]). After adjustment for HLA mismatches, donor and recipient characteristics, and transplant era, donor-recipient biological relationship was associated with higher death-censored allograft failure (hazard ratio, 1.05; 95% CI, 1.01-1.10; P = .03). When stratified by primary disease, this association persisted only for recipients without cystic kidney disease. When stratified by donor race, this association persisted only for transplants from African American donors.

CONCLUSIONS AND RELEVANCE

In this cohort study, living donor kidney transplants from donors biologically related to their recipients had higher rates of allograft failure than transplants from donors unrelated to their recipients after HLA matching was accounted for. Further study is needed to determine which genetic or socioenvironmental factors are associated with this finding.

Utility of Ecological Risk Factors for Evaluation of Transplant Center Performance

There is substantial evidence across different healthcare contexts that social determinants of health are strongly associated with morbidity and mortality in the United States. These factors, including socioeconomic status, behavior and environmental risks, education, social support, healthy food, and access to healthcare also vary widely by region and individual communities. One of the implications of heterogeneity in these risks is the potential impact on measured quality of healthcare providers. In particular, there is concern that providers treating disproportionally vulnerable communities may be disadvantaged by lack of risk adjustment for these factors that affect health but not indicators of quality of care. Recently, the National Quality Forum has endorsed risk adjustment for sociodemographic characteristics based on these concerns. These issues are salient to transplant programs since social determinants of health impact transplant patient outcomes and vary by region. In this viewpoint, we argue that integration of ecological (area-level) factors in risk adjustment models used to assess transplant center quality should be strongly considered. We believe this reform could be accomplished rapidly, would attenuate disparities in access to care by reducing disincentives to treat patients from vulnerable communities, and improve risk adjustment and calibration of models used for center evaluations.

Clinical Events and Renal Function in the First Year Predict Long-Term Kidney Transplant Survival

BACKGROUND

Estimated glomerular filtration rate (eGFR) at 1 year post transplantation has been shown to be a strong predictor of long-term graft survival. However, intercurrent events (ICEs) may affect the relationship between eGFR and failure risk.

METHODS

The OPTN and USRDS databases on single-organ kidney transplant recipients from 2012 to 2016 were linked. Competing risk regressions estimated adjusted subhazard ratios (SHRs) of 12-month eGFR on long-term graft failure, considering all-cause mortality as the competing risk, for deceased donor (DD) and living donor (LD) recipients. Additional predictors included recipient, donor, and transplant characteristics. ICEs examined were acute rejection, cardiovascular events, and infections.

RESULTS

Cohorts comprised 25,131 DD recipients and 7471 LD recipients. SHRs for graft failure increased rapidly as 12-month eGFR values decreased from the reference 60 ml/min per 1.73 m². At an eGFR of 20 ml/min per 1.73 m², SHRs were 13-15 for DD recipients and 12-13 for LD recipients; at an eGFR of 30 ml/min per 1.73 m², SHRs were 5.0-5.7 and 5.0-5.5, respectively. Among first-year ICEs, acute rejection was a significant predictor of long-term graft failure in both DD (SHR=1.63, P<0.001) and LD (SHR=1.51, P=0.006) recipients; cardiovascular events were significant in DD (SHR=1.24, P<0.001), whereas non-CMV infections were significant in the LD cohort (SHR=1.32, P=0.03). Adjustment for ICEs did not significantly reduce the association of eGFR with graft failure.

CONCLUSIONS

Twelve-month eGFR is a strong predictor of long-term graft failure after accounting for clinical events occurring from discharge to 1 year. These findings may improve patient management and clinical evaluation of novel interventions.

Proton-pump inhibitor vs. H2-receptor blocker use and overall risk of CKD progression

Background

The relationship between proton-pump inhibitor (PPI) use and chronic kidney disease (CKD) progression remains controversial. Specifically, there is a lack of data evaluating renal outcomes in established CKD patients. The aim of our study is to determine the risk of progression to end-stage kidney disease (ESKD) or death amongst CKD patients on PPI, histamine-2 receptor blocker (H2B), or no anti-acid therapy.

Methods

Using our CKD registry, we evaluated the relationship between PPI and H2B use and outcomes amongst patients with CKD (eGFR < 60), with at least 2 PCP visits in the year prior. A Cox proportional hazards model was used to evaluate the relationship between medication groups and overall mortality, while competing risks regression models were used to determine the risk of ESKD with death as a competing risk.

Results

25,455 patients met inclusion criteria and were stratified according to medication group: no antacid therapy (15,961), PPI use (8646), or H2B use (848). At 4 years, the cumulative incidence of ESKD with death as a competing risk was 2.0% (95% CI: 1.7, 2.4), 1.5% (0.8, 2.8), and 1.6%(1.4, 1.9) among PPI, H2B, and no medication respectively (P = 0.22). The cumulative incidence of death with ESKD as a competing risk was 17.6% (95% CI: 16.6, 18.6), 16.7% (13.7, 19.8), and 17.3% (16.6, 18.0) (P = 0.71).

Conclusions

Use of PPI in a CKD population was not associated with increased mortality or progression to ESKD when compared to H2 blocker and to no acid suppressing therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02449-0.

Serum triglycerides and risk for death in Stage 3 and Stage 4 chronic kidney disease

BACKGROUND

An elevated triglyceride level is associated with cardiovascular and all-cause mortality in the general population. The associations between serum triglyceride and all-cause mortality among patients with chronic kidney disease (CKD) are unclear.

METHODS

Patients with Stage 3 and Stage 4 CKD (estimated glomerular filtration rate 15-59 mL/min/1.73 m(2)) who had serum triglycerides measured prior to being classified as CKD were included. We examined the associations of serum triglyceride levels with all-cause mortality among 25 641 Stage 3 and Stage 4 CKD patients using Cox proportional hazard models and Kaplan-Meier survival curves.

RESULTS

In the Cox model, after adjusting for relevant covariates including other lipid parameters, serum triglyceride level 150-199 mg/dL was not associated with death [hazard ratio (HR) 1.00, 95% confidence interval (95% CI) 0.92-1.10] relative to serum triglyceride <150 mg/dL while serum triglyceride ≥ 200 mg/dL was associated with a 11% increased hazard for death (95% CI 1.01-1.22). Age modified the association between serum triglyceride levels ≥ 200 mg/dL and mortality with patients <65 years having a 38% higher hazard for death (95% CI 1.15-1.65) and ≥ 65 years with no increased risk for death (HR 0.97, 95% CI 0.88-1.08, P for interaction <0.001). When serum triglycerides were examined as a continuous log-transformed variable, similar associations with mortality were noted.

CONCLUSIONS

Serum triglyceride ≥ 200 mg/dL was independently associated with all-cause mortality in Stage 3 and Stage 4 CKD patients aged <65 years but not among patients of age ≥ 65 years. Future studies should confirm these findings and examine the mechanisms that may explain these associations.

Increased Levels of Tumor Necrosis Factor α Are Associated with an Increased Risk of Cytomegalovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation

Tumor necrosis factor-alpha (TNF) has been implicated in the reactivation of cytomegalovirus (CMV) at a cellular level. We therefore hypothesized that increased posttransplantation TNF levels may be associated with the development of CMV antigenemia (CMV-Ag). We studied 134 patients undergoing allogeneic hematopoietic stem cell transplantation. After excluding CMV-negative donor and recipient pairs, 94 patients were evaluable. By cluster analysis, 2 groups were designated by TNF levels obtained between days 4 and 7 after transplantation: 58 patients had low levels (median, 0 pg/mL; range, 0-5.5 pg/mL), and 36 patients had high levels (median, 43.75 pg/mL; range, 7.5-1756 pg/mL). To determine the independent effect of TNF on the development of CMV-Ag and acute graft-versus-host disease and on survival, Kaplan-Meier and Cox models stratified by TNF patient groups were evaluated. High TNF levels were associated with a more rapid onset of CMV-Ag (P < .001) and with the occurrence of the composite end point of CMV-Ag or death (P < .001). Factors independently associated with CMV-Ag in multivariate analysis were a high TNF level (hazard ratio [HR], 2.57; P = .003) and acute graft-versus-host disease (as a time-dependent covariate; HR, 2.30; P = .010). Factors independently associated with the composite end point of CNV-Ag or death were a high TNF level (HR, 2.42; P < .001) and patient age (per year; HR, 1.93; P = .017). In conclusion, a high posttransplantation TNF level is significantly associated with the risk for developing CMV infection. Early detection of high levels of TNF may be used to identify patients at high risk for developing CMV-Ag.

Outcomes of patients receiving maintenance dialysis admitted over weekends

BACKGROUND

Hospital admissions over weekends have been associated with worse outcomes in different patient populations. The cause of this difference in outcomes remains unclear; however, different staffing patterns over weekends have been speculated to contribute. We evaluated outcomes in patients on maintenance dialysis therapy admitted over weekends using a national database.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

We included nonelective admissions of adult patients (≥18 years) on maintenance dialysis therapy (n = 3,278,572) identified using appropriate International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for 2005-2009 using the Nationwide Inpatient Sample database.

PREDICTOR

Weekend versus weekday admission.

OUTCOMES

The primary outcome measure was all-cause in-hospital mortality. Secondary outcomes included mortality by day 3 of admission, length of hospital stay, time to death, and discharge disposition.

MEASUREMENTS

We adjusted for patient and hospital characteristics, payer, year, comorbid conditions, and primary discharge diagnosis common to maintenance dialysis patients.

RESULTS

There were an estimated 704,491 admissions over weekends versus 2,574,081 over weekdays. Unadjusted all-cause in-hospital mortality was 40,666 (5.8%) for weekend admissions in comparison to 138,517 (5.4%) for weekday admissions (P < 0.001). In a multivariable model, patients admitted over weekends had higher all-cause in-hospital mortality (OR, 1.06; 95% CI, 1.01-1.10) in comparison to those admitted over weekdays and higher mortality during the first 3 days of admission (OR, 1.18; 95% CI, 1.10-1.26). Patients admitted over weekends were less likely to be discharged to home, had longer hospital stays, and had shorter times to death compared with those admitted over weekdays on adjusted analysis.

LIMITATIONS

Use of ICD-9-CM codes to identify patients, defining weekend as midnight Friday to midnight Sunday.

CONCLUSIONS

Maintenance dialysis patients admitted over weekends have increased mortality rates and longer lengths of stay compared with those admitted over weekdays. Further studies are needed to identify the reasons for worse outcomes for weekend admissions in this patient population.

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.

Does Pneumatic Tube System Transport Contribute to Hemolysis in ED Blood Samples?

INTRODUCTION

Our goal was to determine if the hemolysis among blood samples obtained in an emergency department and then sent to the laboratory in a pneumatic tube system was different from those in samples that were hand-carried.

METHODS

The hemolysis index is measured on all samples submitted for potassium analysis. We queried our hospital laboratory database system (SunQuest(®)) for potassium results for specimens obtained between January 2014 and July 2014. From facility maintenance records, we identified periods of system downtime, during which specimens were hand-carried to the laboratory.

RESULTS

During the study period, 15,851 blood specimens were transported via our pneumatic tube system and 92 samples were hand delivered. The proportions of hemolyzed specimens in the two groups were not significantly different (13.6% vs. 13.1% [p=0.90]). Results were consistent when the criterion was limited to gross (3.3% vs 3.3% [p=0.99]) or mild (10.3% vs 9.8% [p=0.88]) hemolysis. The hemolysis rate showed minimal variation during the study period (12.6%-14.6%).

CONCLUSION

We found no statistical difference in the percentages of hemolyzed specimens transported by a pneumatic tube system or hand delivered to the laboratory. Certain features of pneumatic tube systems might contribute to hemolysis (e.g., speed, distance, packing material). Since each system is unique in design, we encourage medical facilities to consider whether their method of transport might contribute to hemolysis in samples obtained in the emergency department.

The role of bypass filters in deceased donor kidney allocation in the United States

Kidney transplant centers set organ offer filters enabling all candidates at their center to be bypassed during allocation of deceased donor kidneys from the UNOS Organ Center. These filters aim to increase allocation efficiency by preemptively screening out offers unlikely to be accepted. National data were used to compare filter settings of 175 centers in 2007 and in 2019. We examined characteristics of centers whose settings became increasingly restrictive over time, and associations between filter settings and organ offer acceptance. Overall, centers became more open to receiving offers over time, from a median 62% of filters open to receiving national offers in 2007 to 73% in 2019. Intravenous drug use filter settings changed most, from 63 to 153 willing centers. Centers with more open filter settings had higher transplant volume and offer acceptance ratios across all risk categories despite preemptively screening out fewer offers compared to centers with less open settings, but similar transplant rates. There was significant geographic heterogeneity in the distribution of centers with more open filter settings. Current center bypass filters may impact patients' access to transplantation without achieving their full potential for improving allocation efficiency.

Burden of Pediatric Heart Failure in the United States

BACKGROUND

There are currently limited accurate national estimates for pediatric heart failure (HF).

OBJECTIVES

This study aims to describe the current burden of primary and comorbid pediatric HF in the United States.

METHODS

International Classification of Diseases, Clinical Modification codes were used to identify HF cases and comorbidities from the Kids' Inpatient Database, National Inpatient Sample, National Emergency Department (ED) Sample, and National Vital Statistics System for 2012 and 2016. To describe HF events, all visits/events among pediatric and adult subjects were included in the analysis. HF events were classified into 1 of 3 groups: 1) no HF; 2) primary HF; or 3) comorbid HF. We compared patients with and without HF and calculated unique event rates with age and sex standardization.

RESULTS

Congenital heart disease, conduction disorders/arrhythmias, and cardiomyopathy were responsible for the majority of pediatric HF-related ED visits and hospitalizations. Compared to 2012, in 2016, there was an increase in comorbid HF ED visits (rate ratio: 1.93; P < 0.001) and primary HF hospitalizations (rate ratio: 1.14; P = 0.002). Pediatric HF burden was lower compared to adult HF; however, deaths in the ED and in-hospital were significantly more likely in children presenting with HF than adults.

CONCLUSIONS

The burden of pediatric HF continues to increase. Compared to adults with HF presenting to the ED and in-hospital, outcomes are inferior and per patient resource use is higher for children hospitalized with HF. National initiatives to understand risk factors for morbidity and mortality in pediatric HF and continued surveillance and mitigation of preventable risk factors may attenuate this uptrend.

Associations of dysnatremias with mortality in chronic kidney disease

Background

Hyponatremia and hypernatremia are associated with death in the general population and those with chronic kidney disease (CKD). We studied the associations between dysnatremias, all-cause mortality and causes of death in a large cohort of Stage 3 and 4 CKD patients.

Methods

We included 45 333 patients with Stage 3 and 4 CKDs followed in a large healthcare system. Associations between hyponatremia (<136 mmol/L) and hypernatremia (>145), and all-cause mortality and causes of death (cardiovascular, malignancy related and non-cardiovascular/non-malignancy related) were studied using Cox proportional hazards and competing risk models.

Results

Dysnatremias were found in 9.2% of the study population. In separate multivariable Cox proportional hazards models using baseline serum sodium levels and time-dependent repeated measures, both hyponatremia and hypernatremia were associated with all-cause mortality. In the competing risk analyses, hyponatremia was significantly associated with increased risk for various cause-specific mortality categories [cardiovascular (hazard ratio, HR 1.16, 95% confidence interval, CI: 1.04, 1.30), malignancy related (HR 1.48, 95% CI: 1.33, 1.65) and non-cardiovascular/non-malignancy deaths (HR 1.25, 95% CI: 1.13, 1.39)], while hypernatremia was significantly associated with higher non-cardiovascular/non-malignancy mortality only (HR 1.36, 95% CI: 1.08, 1.72).

Conclusions

In those with CKD, hyponatremia was associated with all-cause mortality, cardiovascular, malignancy and non-cardiovascular/non-malignancy-related deaths. Hypernatremia was associated with all-cause and non-cardiovascular/non-malignancy-related deaths. Further studies are needed to elucidate the mechanisms of differences in cause-specific death among CKD patients with hyponatremia and hypernatremia.