Longitudinal variance of Donor-Derived Cell-Free DNA (dd-cfDNA) in Stable Kidney Transplant (KTx) patients are influenced by donor/recipient variables.

BACKGROUND: The longitudinal time-course of dd-cfDNA after kidney transplant (KTx) is not well-described. The cut off values of dd-cfDNA in KTx derive from biopsy-coupled single measurements. Meaningful interpretation necessitates understanding of: (1) time variance of dd-cfDNA levels post-KTx, (2) factors determining biologic variability, and (3) relationship to donor and recipient characteristics. We hypothesized that an understanding of the aforementioned factors would better inform clinical decision-making using dd-cfDNA. METHODS: One hundred and twenty five KTx patients with dd-cfDNA obtained longitudinally were included. Univariate analyses were directed at inter-patient variability and intra-patient inter-occasion variability of dd-cfDNA. Multivariate linear regression was used in analyses accounting for repeat measures. RESULTS: At 1-month post KTx median dd-cfDNA: (1) were higher in repeat KTx (.57%, P < .001), and dual KTx (1.10%, P = ns) versus a first KTx (.31%); (2) showed a significant difference in donor after cardiac death (DCD [.45%]) versus living related (LRD [.27%]) donors (P = .036). Longitudinal (1-3 months) dd-cfDNA measurements showed a significant downtrend for all donor types. Panel-reactive antibodies (PRA) were positively correlated with dd-cfDNA. CONCLUSIONS: Repeat Tx, dual Tx, DCD, and PRA are associated with a higher dd-cfDNA. Incorporation of donor/recipient variables and time down post transplant is material for rational interpretation of dd-cfDNA.

Two-year outcomes in de novo renal transplant recipients receiving everolimus-facilitated calcineurin inhibitor reduction regimen from the TRANSFORM study.

TRANSFORM (TRANSplant eFficacy and safety Outcomes with an eveRolimus-based regiMen) was a 24-month, prospective, open-label trial in 2037 de novo renal transplant recipients randomized (1:1) within 24 hours of transplantation to receive everolimus (EVR) with reduced-exposure calcineurin inhibitor (EVR + rCNI) or mycophenolate with standard-exposure CNI. Consistent with previously reported 12-month findings, noninferiority of the EVR + rCNI regimen for the primary endpoint of treated biopsy-proven acute rejection (tBPAR) or estimated glomerular filtration rate (eGFR) <50 mL/min per 1.73 m2 was achieved at month 24 (47.9% vs 43.7%; difference = 4.2%; 95% confidence interval = -0.3, 8.7; P = .006). Mean eGFR was stable up to month 24 (52.6 vs 54.9 mL/min per 1.73 m2 ) in both arms. The incidence of de novo donor-specific antibodies (dnDSA) was lower in the EVR + rCNI arm (12.3% vs 17.6%) among on-treatment patients. Although discontinuation rates due to adverse events were higher with EVR + rCNI (27.2% vs 15.0%), rates of cytomegalovirus (2.8% vs 13.5%) and BK virus (5.8% vs 10.3%) infections were lower. Cytomegalovirus infection rates were significantly lower with EVR + rCNI even in the D+/R- high-risk group (P < .0001). In conclusion, the EVR + rCNI regimen offers comparable efficacy and graft function with low tBPAR and dnDSA rates and significantly lower incidence of viral infections relative to standard-of-care up to 24 months. Clinicaltrials.gov number: NCT01950819.

Development and future deployment of a 5 years allograft survival model for kidney transplantation.

AIM: Identifying kidney transplant patients at highest risk for graft loss prior to loss may allow for effective interventions to improve 5 years survival. METHODS: We performed a 10 years retrospective cohort study of adult kidney transplant recipients (n = 1747). We acquired data from electronic health records, United Network of Organ Sharing, social determinants of health, natural language processing data extraction, and real-time capture of dynamically evolving clinical data obtained within 1 year of transplant; from which we developed a 5 years graft survival model. RESULTS: Total of 1439 met eligibility; 265 (18.4%) of them experienced graft loss by 5 years. Graft loss patients were characterized by: older age, being African-American, diabetic, unemployed, smokers, having marginal donor kidneys and cardiovascular comorbidities. Predictive dynamic variables included: low mean blood pressure, higher pulse pressures, higher heart rate, anaemia, lower estimated glomerular filtration rate peak, increased tacrolimus variability, rejection and readmissions. This Big Data analysis generated a 5 years graft loss model with an 82% predictive capacity, versus 66% using baseline United Network of Organ Sharing data alone. CONCLUSION: Our analysis yielded a 5 years graft loss model demonstrating superior predictive capacity compared with United Network of Organ Sharing data alone, allowing post-transplant individualized risk-assessed care prior to transitioning back to community care.

Everolimus with Reduced Calcineurin Inhibitor Exposure in Renal Transplantation.

Background Everolimus permits reduced calcineurin inhibitor (CNI) exposure, but the efficacy and safety outcomes of this treatment after kidney transplant require confirmation.Methods In a multicenter noninferiority trial, we randomized 2037 de novo kidney transplant recipients to receive, in combination with induction therapy and corticosteroids, everolimus with reduced-exposure CNI (everolimus arm) or mycophenolic acid (MPA) with standard-exposure CNI (MPA arm). The primary end point was treated biopsy-proven acute rejection or eGFR<50 ml/min per 1.73 m2 at post-transplant month 12 using a 10% noninferiority margin.Results In the intent-to-treat population (everolimus n=1022, MPA n=1015), the primary end point incidence was 48.2% (493) with everolimus and 45.1% (457) with MPA (difference 3.2%; 95% confidence interval, -1.3% to 7.6%). Similar between-treatment differences in incidence were observed in the subgroups of patients who received tacrolimus or cyclosporine. Treated biopsy-proven acute rejection, graft loss, or death at post-transplant month 12 occurred in 14.9% and 12.5% of patients treated with everolimus and MPA, respectively (difference 2.3%; 95% confidence interval, -1.7% to 6.4%). De novo donor-specific antibody incidence at 12 months and antibody-mediated rejection rate did not differ between arms. Cytomegalovirus (3.6% versus 13.3%) and BK virus infections (4.3% versus 8.0%) were less frequent in the everolimus arm than in the MPA arm. Overall, 23.0% and 11.9% of patients treated with everolimus and MPA, respectively, discontinued the study drug because of adverse events.Conclusions In kidney transplant recipients at mild-to-moderate immunologic risk, everolimus was noninferior to MPA for a binary composite end point assessing immunosuppressive efficacy and preservation of graft function.

The Impact of Health Care Appointment Non-Adherence on Graft Outcomes in Kidney Transplantation.

BACKGROUND: Non-adherence to medication is a well-studied and known cause of late allograft loss, but it is difficult to measure and prospectively monitor. The aim of this study was to assess if appointment non-adherence was correlated with medication non-adherence and a predictor of graft outcomes. METHODS: This was a longitudinal cohort study that used the National United States Renal Data System and veterans affairs health records data with time-to-event analyses conducted to assess the impact on graft and patient survival. RESULTS: The number of transplants that were included in the analysis was 4,646 (3,656 with complete records); 14.6% of patients had an appointment no show rate of ≥12% (non-adherence). Appointment and medication non-adherence were highly correlated and both were significant independent predictors of outcomes. Those with appointment non-adherence had 1.5 times the risk of acute rejection (22.0 vs. 14.7%, p < 0.0001) and a 65% higher risk of graft loss (adjusted hazards ratio (aHR) 1.65, 95% CI 1.38-1.97, p < 0.0001). There was a significant interaction between appointment and medication non-adherence; those with appointment and medication non-adherence were at very high risk of graft loss (aHR 4.18, 95% CI 3.39-5.15, p < 0.0001), compared to those with only appointment non-adherence (aHR 1.39, 95% CI 0.97-2.01, p = 0.0766) or only medication non-adherence (aHR 2.44, 95% CI 2.11-2.81, p < 0.0001). CONCLUSION: These results demonstrate that non-adherence to health care appointments is a significant and independent risk factor for graft loss.

A randomized, prospective comparison of transition to sirolimus-based CNI-minimization or withdrawal in African American kidney transplant recipients.

BACKGROUND: There is a lack of conclusive evidence to suggest if calcineurin inhibitor (CNI) withdrawal or minimization with sirolimus is the best strategy for African Americans. METHODS: This was a randomized, prospective, open-label, pilot study comparing the two mammalian target of rapamycin (mTOR) transition strategies in adult African Americans between six and 24 wk post-transplant. The primary outcome was a comparison of the eGFR at one yr after conversion. RESULTS: Forty patients were randomized and analyzed in an intent-to-treat fashion. Median day of transition was day 96 (withdrawal) and 68 (minimization). Patients in the CNI-withdrawal group (n = 23) had significantly higher eGFR at one yr compared to the CNI-minimization group (n = 17, 73 vs. 56 mL/min, p = 0.03), as well as a significantly larger increase in eGFR from baseline (12 vs. 5 mL/min, p = 0.03). There were no differences in infections, acute rejection, death, or graft loss. Both regimens were constrained by disproportionately high discontinuation rates despite modest toxicity profiles. CONCLUSION: In spite of considerable withdrawal rate across both study arms, African American kidney transplant recipients who underwent early transition to a sirolimus-based CNI-withdrawal regimen had significantly better graft function at one yr compared to those transitioned to a sirolimus-based CNI-minimization regimen. Clinicaltrials.gov identifier: NCT01005706.

Mild renal dysfunction and long-term adverse outcomes in women with chest pain: results from the National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE).

BACKGROUND: Chronic kidney disease (CKD) is associated with accelerated atherosclerosis and adverse cardiovascular outcomes, but mechanisms are unclear. We hypothesized that mild CKD independently predicts adverse outcomes in women with symptoms and signs of ischemia. METHODS: We categorized 876 women from the Women's Ischemia Syndrome Evaluation cohort according to estimated glomerular filtration rate (eGFR) (eGFR ≥90 mL/min per 1.73 m(2) [normal], 60-89 mL/min per 1.73 m(2) [mild CKD], ≤59 mL/min per 1.73 m(2) [severe CKD]). Time to death from all-cause and cardiovascular causes and major adverse outcomes were assessed by multivariate regression adjusted for baseline covariates. RESULTS: Obstructive coronary artery disease (CAD) was present only in few patients (39%). Even after adjusting for CAD severity, renal function remained a strong independent predictor of all-cause and cardiac mortality (P < .001). Every 10-unit decrease in eGFR was associated with a 14% increased risk of all-cause mortality (adjusted hazard ratio [AHR] 1.14 [1.08-1.20], P < .0001), 16% increased risk of cardiovascular mortality (AHR 1.16 [1.09-1.23], P < .0001), and 9% increased risk of adverse cardiovascular events (AHR 1.09 [1.03-1.15], P = .002). CONCLUSIONS: Even mild CKD is a strong independent predictor of all-cause and cardiac mortality in women with symptoms/signs of ischemia, regardless of underlying obstructive CAD severity, underscoring the need to better understand the interactions between ischemic heart disease and CKD.

Identifying endpoints to predict the influence of immunosuppression on long-term kidney graft survival.

Identifying a short-term endpoint for use in clinical trials that accurately reflects the influence of specific immunosuppressive regimens on long-term kidney graft survival is challenging. The number, timing, type (T-cell-mediated or antibody mediated), and severity of biopsy-proven acute rejection (BPAR) episodes in terms of histological changes and functional impact are highly influential for graft prognosis, and a crude measure of overall acute rejection incidence alone is unlikely to be a robust predictor of graft outcome. A series of studies has shown remarkably consistent results in terms of the cutoff point for one-yr renal function which predicts poor long-term graft survival, indicating that a threshold of 50 mL/min/1.73 m(2) is likely to be appropriate. Estimated glomerular filtration rate at one yr post-transplant discriminates effectively among immunosuppressive regimens with regard to graft survival, primarily calcineurin inhibitor reduction strategies. Several other factors that can affect graft survival, such as pathological changes in the graft, may be partly influenced by the immunosuppressive regimen, but the contribution of drug therapy is difficult to define. A combined approach in which both treated BPAR and renal function at one yr are used to assess novel immunosuppressive regimens appears to be promising as the emphasis shifts toward sustaining kidney allograft survival over the long term.

Optimizing finite resources: Pharmacist chart reviews in an outpatient kidney transplant clinic.

OBJECTIVE: To determine if a pharmacist-executed comprehensive chart review could serve as sufficient substitution for direct participation during outpatient clinic visits in the postdischarge follow-up treatment of kidney transplant recipients. DESIGN: Retrospective, longitudinal, cross-sectional study. SETTING: Acute and chronic transplant clinics at the Medical University of South Carolina, Charleston, SC. PARTICIPANTS: 219 individual kidney transplant recipients. MAIN OUTCOME MEASURES: Effectiveness of chart review assessments (with written notes) as compared with in-clinic assessments (with verbal communication with transplant providers followed by documentation by pharmacists). An independent transplant provider graded pharmacist recommendations by severity. All recommendations were compared with the provider's plan to determine if the recommendations were incorporated. RESULTS: During the 3-month study period, 170 pharmacist chart reviews were written and 175 clinic visits involved direct pharmacist participation. Providers accepted a greater percentage of recommendations that were delivered directly compared with recommendations presented via a note in the patient folder following chart review (92% vs. 28%, respectively; P <0.0001). Directly provided recommendations were also associated with higher severity scores. CONCLUSION: The results of this study suggest that comprehensive chart review by pharmacists prior to patient clinic visits may not be as effective as in-person consultation in communicating recommendations to providers. Further research is needed in similar clinic settings.

Prospective randomized controlled trial of rabbit antithymocyte globulin compared with IL-2 receptor antagonist induction therapy in kidney transplantation.

OBJECTIVE: The aim of this study was to determine the safety and efficacy of induction with rabbit antithymocyte globulin (RATG) compared with interleukin-2 receptor antagonists in a racially diverse kidney transplant patient population under modern immunosuppression. BACKGROUND: The optimal induction therapy in patients at risk for rejection, particularly black recipients, in the modern era of immunosuppression with flow cytometry-based cross-matching is unclear. METHODS: This was a prospective, risk-stratified, randomized, single-center, open-label study of 200 consecutively enrolled patients in a large academic teaching center. Patients were randomized to receive either daclizumab or basiliximab versus RATG for induction in combination with tacrolimus, mycophenolate mofetil, and corticosteroids. Patients were stratified between groups to ensure equal numbers of black, retransplants, high panel reactive antibodies (PRAs) (>20%), and prolonged cold ischemic times (>24 hours) in each group. Primary outcome measure is treatment efficacy defined as the incidence of biopsy-proven acute rejection and estimated creatinine clearance. Patients were followed up for 12 months. Renal transplant recipients were included if they were adult (≥18 years old) and received an allograft from a deceased, living unrelated, or nonhuman leukocyte antigen identical living-related donor. RESULTS: A total of 200 patients (n = 98 in the interleukin-2 receptor antagonists, and n = 102 in the RATG) were enrolled from February 2009 through July 2011. One-year acute rejection rates were low and similar between groups (10% in the interleukin-2 receptor antagonist group vs 6% in the RATG group; P = 0.30). Creatinine clearance was also similar between groups (interleukin-2 receptor antagonist group 56 ± 20 mL/min per 1.73 m2 vs RATG group 55 ± 22 mL/min per 1.73 m2; P = 0.73). Subanalysis of recipient race revealed that in blacks only RATG was protective against 6- and 12-month acute rejection, without an increased risk of infection. Induction did not affect rejection rates according to recipient calculated PRAs; however, RATG was associated with an increased risk of BK virus in low-PRA patients. CONCLUSIONS AND RELEVANCE: RATG induction provides improved protection against early acute rejection in black renal transplant recipients, whereas sensitized patients do not seem to demonstrate a similar benefit from this therapy. This study is registered at Clinicaltrials.gov (NCT00859131).

Disseminated adenoviral infection masquerading as lower urinary tract voiding dysfunction in a kidney transplant recipient.

Viral infections continue to cause significant morbidity in immunosuppressed kidney transplant patients. Although cytomegalovirus, Epstein-Barr virus and polyoma "BK" virus are more frequently encountered, the Adenovirus can cause multi-organ system infections, and may be difficult to diagnose because it is not often considered in the initial work up in kidney transplant recipients. We present an unusual case of a kidney recipient 1 year post-transplant with disseminated adenoviral infection, who had an initial presentation of lower urinary tract voiding dysfunction with hematuria and sterile pyuria. This progressed to a severe tubulointerstitial nephritis and acute kidney injury that improved with reduction of immunosuppression. Serial blood viral loads are useful for monitoring the course of infection. Urinary adenoviral infection should be considered in the differential diagnosis whenever a kidney transplant recipient presents with unexplained lower tract voiding dysfunction, hematuria, and sterile pyuria. The allograft kidney and bladder can be targets of viral proliferation. Early diagnosis with reduction of immunosuppressive therapy is essential to clear the virus and maintain allograft function.

Hypertension after kidney transplantation: a pathophysiologic approach.

Post-transplant hypertension is associated with decreased graft and patient survival and cardiovascular morbidity. Unfortunately, post-transplant hypertension is often poorly controlled. Important risk factors include immunosuppressive medications, complications of the transplant surgery, delayed graft function, rejection, and donor and recipient risk factors. The effects of immunosuppressive medications are multifactorial including increased vascular and sympathetic tone and salt and fluid retention. The immunosuppressive agents most commonly associated with hypertension are glucocorticoids and calcineurin inhibitors. Drug therapy for hypertension should be based on the comorbidities and pathophysiology. Evidence-based approaches to defining and treating hypertension in renal transplant recipients are predominantly extrapolated from large-scale studies performed in the general population. Thus, there continues to be a need for larger studies examining the pathophysiology, diagnosis and treatment of hypertension in renal transplant recipients.

The impact of surveillance and rapid reduction in immunosuppression to control BK virus-related graft injury in kidney transplantation.

We prospectively screened 609 consecutive kidney (538) and kidney-pancreas (71) transplant recipients for BK viremia over a 4-year interval using polymerase chain reaction viral load detection and protocol kidney biopsies. We found that BK viremia is common at our center: total cases 26.7%, cases during first year 21.3% (mean 4 months), and recipients with ≥ 10 000 copies/ml 12.3%. We found few predictive clinical or demographic risk factors for any BK viremia or viral loads ≥ 10,000 copies/ml, other than prior treatment of biopsy confirmed acute rejection and/or higher immunosuppressive blood levels of tacrolimus (P = 0.001) or mycophenolate mofetil (P = 0.007). Viral loads at diagnosis (<10 000 copies/ml) demonstrated little impact on graft function or survival. However, rising copy numbers demand early reductions in immunosuppressive drug doses of at least 30-50%. Viral loads >185 000 copies/ml at diagnosis were predictive of BK virus-associated nephropathy (BKVAN; OR: 113.25, 95% CI: 17.22-744.6, P < 0.001). Surveillance for BK viremia and rapid reduction of immunosuppression limited the incidence of BKVAN to 1.3%. The addition of leflunomide or ciprofloxacin to immunosuppressive dose reduction did not result in greater rates of viral clearance. These data support the role of early surveillance for BK viremia to limit the impact on transplant outcome, although the most effective schedule for screening awaits further investigation.

Shifting Clinical Trial Endpoints in Kidney Transplantation: The Rise of Composite Endpoints and Machine Learning to Refine Prognostication.

The measurement of outcomes in kidney transplantation has been more accurately documented than almost any other surgical procedure result in recent decades. With significant improvements in short- and long-term outcomes related to optimized immunosuppression, outcomes have gradually shifted away from conventional clinical endpoints (ie, patient and graft survival) to surrogate and composite endpoints. This article reviews how outcomes measurements have evolved in the past 2 decades in the setting of increased data collection and summarizes recent advances in outcomes measurements pertaining to clinical, histopathological, and immune outcomes. Finally, we discuss the use of composite endpoints and Bayesian concepts, specifically focusing on the integrative box risk prediction score, in conjunction with machine learning to refine prognostication.

Redesigning Kidney Disease Care to Improve Value Delivery.

This article describes the articulation, development, and deployment of a machine learning (ML) model-driven value solution for chronic kidney disease (CKD) in a health system. The ML model activated an electronic medical record (EMR) trigger that alerted CKD patients to seek primary care. Simultaneously, primary care physicians (PCPs) received an alert that a CKD patient needed an appointment. Using structured checklists, PCPs addressed and controlled comorbid conditions, reconciled drug dosing and choice to CKD stage, and ordered prespecified laboratory and imaging tests pertinent to CKD. After completion of checklist prescribed tasks, PCPs referred patients to nephrology. CKD patients had multiple comorbidities and ML recognition of CKD provided a facile insight into comorbid burden. Operational results of this program have exceeded expectations and the program is being expanded to the entire health system. This paradigm of ML-driven, checklist-enabled care can be used agnostic of EMR platform to deliver value in CKD through structured engagement of complexity in health systems.

Low 25-hydroxyvitamin D levels and mortality in non-dialysis-dependent CKD.

BACKGROUND: Low 25-hydroxyvitamin D (25[OH]D) levels are common in patients with non-dialysis-dependent chronic kidney disease (CKD). The associations between low 25(OH)D levels and mortality in non-dialysis-dependent patients with CKD are unclear. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Patients with stages 3-4 CKD (estimated glomerular filtration rate, 15-59 mL/min/1.73 m(2); n = 12,673) who had 25(OH)D levels measured after the diagnosis of CKD in the Cleveland Clinic Health System. PREDICTOR: 25(OH)D levels categorized into 3 groups: <15, 15-29, and ≥30 ng/mL. OUTCOMES: We examined factors associated with low 25(OH)D levels and associations between low 25(OH)D levels and all-cause mortality (ascertained using the Social Security Death Index and our electronic medical record) using logistic regression, Cox proportional hazard models, and Kaplan-Meier survival curves. MEASUREMENTS: 25(OH)D was measured using chemiluminescence immunoassay. RESULTS: Of 12,763 patients with CKD, 15% (n = 1,970) had 25(OH)D levels <15 ng/mL, whereas 45% (n = 5,749) had 25(OH)D levels of 15-29 ng/mL. Male sex, African American race, diabetes, coronary artery disease, and lower estimated glomerular filtration rate were associated significantly with 25(OH)D level <30 ng/mL. A graded increase in risk of 25(OH)D level <30 ng/mL was evident across increasing body mass index levels. Patients who had 25(OH)D levels measured in fall through spring had higher odds for 25(OH)D levels <30 ng/mL. After covariate adjustment, patients with CKD with 25(OH)D levels <15 ng/mL had a 33% increased risk of mortality (95% CI, 1.07-1.65). The group with 25(OH)D levels of 15-29 ng/mL did not show a significantly increased risk of mortality (HR, 1.03; 95% CI, 0.86-1.22) compared with patients with 25(OH)D levels ≥30 ng/mL. LIMITATIONS: Single-center observational study, lack of data for albuminuria and other markers of bone and mineral disorders, and attrition bias. CONCLUSIONS: 25(OH)D level <15 ng/mL was associated independently with all-cause mortality in non-dialysis-dependent patients with CKD.

The relative risk of overall graft loss and acute rejection among African American renal transplant recipients is attenuated with advancing age.

BACKGROUND: Graft loss rates are elevated among African American (AA) kidney transplant recipients. This may be attributable to immunological responses, socioeconomic disparities, comorbid conditions and access to care, but it is unclear whether risks are uniform in the AA population. METHODS: We utilized multivariable models with the national SRTR database for adult recipients transplanted from 2000 to 2009 (n = 112,120) to investigate whether risks of graft loss, death and acute rejection between AAs and Caucasians vary with age. RESULTS: Relative to Caucasians, AA recipients had significantly higher risk of overall graft loss among patients aged 18-49 (AHR = 1.37, 95% CI 1.30-1.43) but comparable risk among patients aged >65 (AHR = 1.04, 95% CI 0.96-1.13). Among recipients aged 18-34, AAs had higher risk of acute rejection (AOR = 1.33, 95% CI 1.12-1.57) but similar likelihood among recipients aged >65 (AOR = 0.94, 95% CI 0.75-1.17). Differences between race groups, as well as the relatively higher risks among younger AAs, were most pronounced following one yr post-transplantation and diminished with presence of other risk factors. CONCLUSIONS: Elevated risks of overall graft loss and acute rejection are present among younger but not older AA kidney transplant recipients. These findings may have important implications for treatment decisions, follow-up protocols and designation of "high-risk" patients.

Outcomes of Surgical Mitral and Aortic Valve Replacements Among Kidney Transplant Candidates: Implications for Valve Selection.

Background Limited literature exists that evaluated outcomes of kidney transplant-eligible patients who are having dialysis and who are undergoing valve replacement. Our main objective in this study was to compare mortality, reoperation, and bleeding episodes between bioprosthetic and mechanical valve procedures among kidney transplant-eligible patients who are having dialysis. Methods and Results We studied 887 and 1925 dialysis patients from the United States Renal Data System, who underwent mitral valve replacement and aortic valve replacement (AVR) after being waitlisted for a kidney transplant (2000-2015), respectively. Time to death, time to reoperation, and time to bleeding requiring hospitalizations were compared separately for AVR and mitral valve replacement. Kaplan-Meier survival curves, Cox proportional hazards model for time to death, accelerated time to event model for time to reoperation, and counting process model for time to recurrent bleeding were used. There were no differences in mortality (hazard ratio [HR], 0.92; 95% CI, 0.77-1.09) or risk of reoperation or risk of significant bleeding events between bioprosthetic and mechanical mitral valve replacement. However, mechanical AVR was associated with a modestly significant less hazard of death (HR, 0.83; 95% CI, 0.74-0.94) compared with bioprosthetic AVR. There were no differences in time to reoperation, or time to significant bleeding events between bioprosthetic and mechanical AVR. Conclusions For kidney transplant waitlisted patients who are on dialysis and who are undergoing surgical valve replacement, bioprosthetic and mechanical valves have comparable survival, reoperation rates, and bleeding episodes requiring hospitalizations at both mitral and aortic locations. These findings emphasize that an individualized informed decision is recommended when choosing the type of valve for this special group of patients having dialysis.

Type 1 Diabetes incidence among youth in Utah: A geographical analysis.

Type 1 Diabetes (T1D) poses an increasing threat to public health, as incidence rates continue to rise globally. However, the etiology of T1D is still poorly understood, especially from the perspective of geography. The objective of this research is to examine the incidence of T1D among youth and to identify high-risk clusters and their association with socio-demographic and geographic variables. The study area was the entire state of Utah and included youth with T1D from birth to 19 years of age from 1998 to 2015 (n = 4161). Spatial clustering was measured both globally and locally using the Moran's I statistic and spatial scan statistic. Ordinary least squares (OLS) regression was used to measure the association of high-risk clusters with certain risk factors at the Census Block Group (CBG) level. The mean age at diagnosis was 9.3 years old. The mean incidence rate was 25.67 per 100,000 person-years (95% CI, 24.57-26.75). The incidence rate increased by 14%, from 23.94 per100,000 person-years in 1998 to 27.98 per 100,000 person-years in 2015, with an annual increase of 0.80%. The results of the spatial scan statistic found 42 high-risk clusters throughout the state. OLS regression analysis found a significant association with median household income, population density, and latitude. This study provides evidence that incidence rates of T1D are increasing annually in the state of Utah and that significant geographic high-risk clusters are associated with socio-demographic and geographic factors.

Hidden selection bias deriving from donor organ characteristics does not affect performance evaluations of kidney transplant centers.

BACKGROUND: Transplant center performance evaluations have garnered substantial attention in recent years. Among sources of bias that may affect measured performance are underlying characteristics of donor organs. An unresolved question is whether centers accepting higher-risk donations are placed in jeopardy for lower evaluations independent of actual quality of care. OBJECTIVE: The primary aim was to assess whether unmeasured characteristics of donor organs impact risk-adjusted outcomes used for center performance evaluations. SUBJECTS: The study included adult kidney transplant recipients (n = 53,791) from 1994 to 2008 from a national registry. RESEARCH DESIGN: We compared adjusted graft survival with use of paired-donor kidneys (allocated to high- and low-performing centers) and unpaired donor kidneys to investigate whether measured center performance was consistent with organs derived from the same donor (minimizing the influence of noncodified risk factors). RESULTS: The primary finding was that differences between centers were unaffected by use of paired or unpaired donations (hazard ratio for patients transplanted at high performing centers with paired kidneys = 0.63 [95% CI, 0.53-0.74] and with unpaired kidneys = 0.66 [95% CI, 0.62-0.70], P value for interaction = 0.52). This finding was consistent over 5 consecutive cohorts, based on either concurrent or prospective outcomes and by altering the threshold criteria for identification of performance outliers. CONCLUSIONS: Results indicate that underlying selection bias from donor characteristics does not impact transplant center evaluations. This is important evidence that donor selection is not a primary driver for evaluated quality of care among transplant centers and acceptance of higher-risk kidneys should not be perceived as a primary threat to measured performance.