Where you live matters: Area deprivation predicts poor survival and liver transplant waitlisting.

Social determinants of health (SDOH) are important predictors of poor clinical outcomes in chronic diseases, but their associations among the general cirrhosis population and liver transplantation (LT) are limited. We conducted a retrospective, multiinstitutional analysis of adult (≥18-years-old) patients with cirrhosis in metropolitan Chicago to determine the associations of poor neighborhood-level SDOH on decompensation complications, mortality, and LT waitlisting. Area deprivation index and covariates extracted from the American Census Survey were aspects of SDOH that were investigated. Among 15 101 patients with cirrhosis, the mean age was 57.2 years; 6414 (42.5%) were women, 6589 (43.6%) were non-Hispanic White, 3652 (24.2%) were non-Hispanic Black, and 2662 (17.6%) were Hispanic. Each quintile increase in area deprivation was associated with poor outcomes in decompensation (sHR [subdistribution hazard ratio] 1.07; 95% CI 1.05-1.10; P < .001), waitlisting (sHR 0.72; 95% CI 0.67-0.76; P < .001), and all-cause mortality (sHR 1.09; 95% CI 1.06-1.12; P < .001). Domains of SDOH associated with a lower likelihood of waitlisting and survival included low income, low education, poor household conditions, and social support (P < .001). Overall, patients with cirrhosis residing in poor neighborhood-level SDOH had higher decompensation, and mortality, and were less likely to be waitlisted for LT. Further exploration of structural barriers toward LT or optimizing health outcomes is warranted.

Safety and effectiveness of the novel Myval Octacor transcatheter heart valve in severe, symptomatic aortic valve stenosis - A real-world Indian experience (The OCTACOR India Study).

PURPOSE: To evaluate the safety and effectiveness of the novel, next-generation Myval Octacor - Transcatheter Heart Valve (THV) in patients with severe, symptomatic, native aortic stenosis (AS). METHODS: This multicenter, real-world observational registry included 123 patients with severe symptomatic AS, across 16 Indian centers who underwent treatment with the novel Myval Octacor THV. Study endpoints included all-cause mortality, all stroke, acute kidney injury (AKI), major vascular complications, moderate or severe paravalvular leakage (PVL) and new permanent pacemaker implantation (PPI) until 30 days follow-up. RESULTS: Of the 123 patients (average age 70.07 ± 8.33 years), 37.4 % (n = 46) were female and 39.84 % presented with bicuspid valves. The technical success rate of the procedure was 100 % and the device success rate at 30 days was 98.4 %. At 30 days (n = 123) after the procedure, the overall mortality was 1.6 %. AKI occurred in 1.6 % of patients and there was no incidence of stroke, bleeding (types 3 and 4), and major vascular complications. In an analysis of 31 patients whose echocardiographic parameters were available across all timepoints, there were significant improvements in the mean pressure gradient (54.31 ± 18.19 mmHg vs. 10.42 ± 4.24 mmHg; p < 0.0001) and effective orifice area (0.66 ± 0.21 cm2 vs. 1.80 ± 0.44 cm2; p < 0.0001) from baseline to the 30-day follow-up. None of the patients experienced severe PVL, while moderate PVL was observed in two patients (1.6 %). CONCLUSIONS: Early outcomes of the next-generation, novel Myval Octacor THV proved its safety and effectiveness in the treatment of severe AS.

Evaluation of Opening Offers Early for Deceased Donor Kidneys at Risk of Nonutilization.

BACKGROUND: Reducing nonutilization of kidneys recovered from deceased donors is a current policy concern for kidney allocation in the United States. The likelihood of nonutilization is greater with a higher kidney donor risk index (KDRI) offer. We examine how opening offers for organs with KDRI >1.75 to the broader waitlist at varying points of time affects usage rates. METHODS: We simulate kidney allocation using data for January 2018 to June 2019 from Organ Procurement and Transplantation Network. For the simulation experiment, allocation policy is modified so that KDRI >1.75 organs are offered to all local candidates (same donation service area) after a set amount of cold time simultaneously. Open offers to candidates nationally are similarly examined. RESULTS: Simulation results ( n =50 replications) estimate that opening offers locally for KDRI >1.75 after 10 hours yields a nonutilization rate of 38% (range: 35%-42%), less than the prevailing rate of 55% of KDRI >1.75 kidneys. Opening offers after 5 hours yields 30% (range: 26%-34%), reducing the prevailing nonutilization rate by 45%. Opening offers nationally after 10 and 5 hours yields nonutilization rates of 11% (range: 8%-15%) and 6% (range: 4%-9%) for KDRI >1.75 kidneys, respectively. CONCLUSIONS: Simulation findings indicate that opening offers and adjusting their timing can significantly reduce nonutilization of high-KDRI kidneys.

Physician Preferences when Selecting Candidates for Lower-Quality Kidney Offers.

BACKGROUND: In the United States, more than 50% of kidneys in the lowest 15% quality range (those with Kidney Donor Profile Index >85) are discarded. Studies suggest that using more of these kidneys could benefit patients waiting for a transplant. This study assesses the trade-offs physicians make when selecting recipients for lower-quality kidneys. METHODS: A discrete choice experiment (DCE) was administered to surgeons and nephrologists in the United States who are involved in kidney acceptance decisions. The DCE presented kidneys that varied in terms of Kidney Donor Profile Index, expected cold ischemia time, donor age, pump parameters, serum creatinine levels, glomerulosclerosis, donor diabetes status, and whether donation was made after circulatory death. Candidate characteristics included recipients' age, diabetes history, time on dialysis, ejection fraction, HLA mismatch, calculated panel reactive antibody, and Karnofsky performance score. Regression analysis was used to estimate acceptability weights associated with kidney and recipient characteristics. RESULTS: A total of 108 physicians completed the DCE. The likelihood of acceptance was significantly lower with deterioration of kidney quality, expected cold ischemia time at transplantation, and missing biopsy and pump information. Acceptance was prioritized for patients who were higher on the waiting list, younger recipients, those who have spent less time on dialysis, and those without a history of diabetes. Performance status (Karnofsky score) and calculated panel reactive antibody also had a statistically significant but smaller association. Finally, ejection fraction had a marginally significant association, and HLA match had no significant association with the acceptance of marginal kidneys. A group of respondents were found to be primarily concerned about cold ischemia time. CONCLUSIONS: In this DCE, physicians considered the recipient characteristics that inform expected post-transplant survival score when they decided whether to accept a marginal kidney for a given recipient.

Angiographic quantification of aortic regurgitation following myval octacor implantation; independent core lab adjudication.

BACKGROUND: The balloon expandable Myval transcatheter heart valve (THV) showed encouraging results regarding residual aortic regurgitation (AR) from multiple observational studies. The newly designed Myval Octacor has been introduced recently, aiming for a reduction in AR and improved performance. OBJECTIVES: The focus of this study is to report the incidence of AR using the validated quantitative Videodensitometry angiography technology (qLVOT-AR%) in the first in human use of the Myval Octacor THV system. METHODOLOGY: We report on the first in human use of the Myval Octacor THV system in 125 patients in 18 Indian centres. Independent retrospective analysis of the final aortograms following implantation of the Myval Octacor was performed using the CAAS-A-Valve software. AR is reported as a regurgitation fraction. The previously validated cutoff values have been used to identify ≥moderate AR (RF% >17%), mild (6% < RF% ≤17%), and none or trace AR (RF% ≤ 6%). RESULTS: Final aortogram was analysable for 103 patients (84.4%) among the 122 available aortograms. 64 (62%) patients, had tricuspid aortic valve (TAV), 38 (37%) with bicuspid AV (BAV), and one with unicuspid AV. The median absolute RF% was 2% [1, 6], moderate or more AR incidence was 1.9%, mild AR in 20.4%, and none or trace AR in 77.7%. The two cases with RF% >17% were in the BAV group. CONCLUSION: The initial results of Myval Octacor using quantitative angiography-derived regurgitation fraction demonstrated a favourable outcome regarding residual AR, possibly due to improved device design. Results must be confirmed in a larger randomised study, including other imaging modalities.

Kidney organ allocation: reducing discards.

PURPOSE OF REVIEW: The donation and kidney transplant system in the United States is challenged with reducing the number of kidneys that are procured for transplant but ultimately discarded. That number can reach 20% of donated kidneys each year. RECENT FINDINGS: The reasons for these discards, in the face of overwhelming demand, are multiple. SUMMARY: The authors review the data supporting a number of potential causes for high discard rates as well as provide potential solutions to the problem.

Transcatheter Aortic Valve Implantation in the Descending Aorta: History Revisited!

An elderly patient with significant aortic regurgitation presented with heart failure. Dilation of the aortic root precluded a transcatheter anatomic site valve implantation, and prohibitive operative risk ruled against surgical implantation. A bail-out transcatheter implantation of the aortic valve in the descending aorta was successfully carried out with satisfactory outcomes.

Patient Preferences for Waiting Time and Kidney Quality.

BACKGROUND AND OBJECTIVES: Approximately 20% of deceased donor kidneys are discarded each year in the United States. Some of these kidneys could benefit patients who are waitlisted. Understanding patient preferences regarding accepting marginal-quality kidneys could help more of the currently discarded kidneys be transplanted. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study uses a discrete choice experiment that presents a deceased donor kidney to patients who are waiting for, or have received, a kidney transplant. The choices involve trade-offs between accepting a kidney today or a future kidney. The options were designed experimentally to quantify the relative importance of kidney quality (expected graft survival and level of kidney function) and waiting time. Choices were analyzed using a random-parameters logit model and latent-class analysis. RESULTS: In total, 605 participants completed the discrete choice experiment. Respondents made trade-offs between kidney quality and waiting time. The average respondent would accept a kidney today, with 6.5 years of expected graft survival (95% confidence interval, 5.9 to 7.0), to avoid waiting 2 additional years for a kidney, with 11 years of expected graft survival. Three patient-preference classes were identified. Class 1 was averse to additional waiting time, but still responsive to improvements in kidney quality. Class 2 was less willing to accept increases in waiting time for improvements in kidney quality. Class 3 was willing to accept increases in waiting time even for small improvements in kidney quality. Relative to class 1, respondents in class 3 were likely to be age ≤61 years and to be waitlisted before starting dialysis, and respondents in class 2 were more likely to be older, Black, not have a college degree, and have lower Karnofsky performance status. CONCLUSIONS: Participants preferred accepting a lower-quality kidney in return for shorter waiting time, particularly those who were older and had lower functional status.

Implications of Accumulated Cold Time for US Kidney Transplantation Offer Acceptance.

BACKGROUND AND OBJECTIVES: Reducing discard is important for the US transplantation system because nearly 20% of the deceased donor kidneys are discarded. One cause for the discards is the avoidance of protracted cold ischemia times. Extended cold ischemia times at transplant are associated with additional risk of graft failure and patient mortality. A preference for local (within the same donor service area) or low-Kidney Donor Risk Index organs, the endogeneity of cold ischemia time during organ allocation, and the use of provisional offers all complicate the analysis of cold ischemia times' influence on kidney acceptance decision making. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using January 2018 to June 2019 Organ Procurement and Transplantation Network data, we modeled the probability of accepting an offer for a kidney after provisional acceptance. We use logistic regression that includes cold ischemia time, Kidney Donor Risk Index, and other covariates selected from literature. Endogeneity of cold ischemia time was treated by a two-stage instrumental variables approach. RESULTS: Logistic regression results for 3.33 million provisional acceptances from 12,369 donors and 108,313 candidates quantify trade-offs between cold ischemia time at the time of offer acceptance and donor-recipient characteristics. Overall, each additional 2 hours of cold ischemia time affected acceptance for nonlocal and local recipients (odds ratio, 0.75; 95% confidence interval, 0.73 to 0.77, odds ratio, 0.88; 95% confidence interval, 0.86 to 0.91; P<0.001). For Kidney Donor Risk Index >1.75 (Kidney Donor Profile Index >85) kidneys, an additional 2 hours of cold ischemia time for nonlocal and local recipients was associated with acceptance with odds ratio, 0.58; 95% confidence interval, 0.54 to 0.63 (nonlocal) and odds ratio, 0.65; 95% confidence interval, 0.6 to 0.7 (local); P<0.001. The effect of an additional 2 hours of cold ischemia time on acceptance of kidneys with Kidney Donor Risk Index ≤1.75 (Kidney Donor Profile Index ≤85) was less pronounced for nonlocal offers (odds ratio, 0.82; 95% confidence interval, 0.80 to 0.85; P<0.001) and not significant for local offers. CONCLUSIONS: The acceptability of marginal organs was higher when placements were nearer to the donor and when cold ischemia time was shorter.

Prevalence and Clinical Features of Portopulmonary Hypertension in Patients With Hepatic Cirrhosis: An Echocardiographic Study.

Objective The present study was conducted to delineate the prevalence and clinical features of portopulmonary hypertension in patients with hepatic cirrhosis. Possible associations between echocardiographic variables and portopulmonary hypertension were also explored. Methods A prospective, observational study was conducted between September 2017 and August 2018. Differences in demographics, clinical presentation, laboratory findings, and echocardiographic findings in cirrhosis patients with and without portopulmonary hypertension were compared. Results The prevalence of portopulmonary hypertension in patients with hepatic cirrhosis was found to be 9.3%. Hemoglobin was significantly lower among patients with portopulmonary hypertension compared to those without portopulmonary hypertension (5.50±0.68 g/dl vs. 7.26±1.43 g/dl, p=0.001). All patients with portopulmonary hypertension displayed right atrial (major: p=0.0001 and minor: p=0.001) and right ventricular (basal, p=0.0001; longitudinal, p=0.0001) dilation. Several variables such as right ventricular systolic pressure (p=0.0001), pulmonary artery diameter (major: p=0.0001; right: p=0.0001; and left: p=0.007), pulmonary vascular resistance (p=0.0001), tricuspid regurgitation (p=0.0001), pulmonary regurgitation peak pressure gradient (p=0.0001), pulmonary regurgitation end diastolic gradient (p=0.0001), left atrial dimension (major axis: p=0.002), left atrial volume (p=0.04), left ventricular outflow tract (p=0.001), inferior vena cava diameter (p=0.001), and inferior vena cava collapsibility (p=0.001) were higher in patients with portopulmonary hypertension compared to patients without portopulmonary hypertension. Conclusions The present study revealed a 9.3% prevalence of portopulmonary hypertension among patients with hepatic cirrhosis. Patients with portopulmonary hypertension displayed significantly lower haemoglobin levels, right and left ventricular dilation, and higher values of several echocardiographic variables as compared to those without portopulmonary hypertension.

The Role of Procurement Biopsies in Kidney Acceptance Decision Making and Kidney Discard: Perceptions of Physicians, Nurse Coordinators, and OPO Staff and Directors.

Procurement biopsies suffer from challenges with quality and reproducibility and are linked to kidney discard. Nonetheless, procurement biopsies are obtained for the majority of kidneys in the United States, and biopsy findings are commonly relied upon in kidney acceptance decisions. Methods: We conducted in-depth, semistructured interviews with 30 surgeons, nephrologists, nurse coordinators, and organ procurement organization (OPO) staff and directors to assess perceptions of factors contributing to kidney discard and strategies to reduce kidney discard, with a focus on the role of procurement biopsies. Thematic analysis was used to analyze qualitative data. Results: Three main themes emerged: (1) participants emphasized the importance of biopsy findings in making acceptance decisions but expressed concerns about a lack of standardization and quality control; (2) participants reported large variations in the level of importance placed on biopsy findings, the level of reliance on glomerulosclerosis in particular, and the cutoffs used; and (3) participants disagreed about how often procurement biopsies should be taken, with some supporting stricter limits on which kidneys are biopsied and others preferring a biopsy for most kidney offers. Conclusions: These findings support the development of standard practices for which kidneys require biopsy, how the biopsy material is prepared, and how the biopsy is interpreted. Variability in kidney acceptance practices across centers and the use of biopsy findings in guiding recipient selection also lend support to policies to allocate kidneys with suboptimal histological findings to the centers that are willing to use such kidneys and the patients who could most benefit from such offers.

30-Day and 1-Year Outcomes With HYDRA Self-Expanding Transcatheter Aortic Valve: The Hydra CE Study.

OBJECTIVES: This study sought to evaluate the 30-day and 1-year safety and performance of the Hydra transcatheter aortic valve (THV) (in the treatment of symptomatic severe aortic stenosis in patients at high or extreme surgical risk. BACKGROUND: The Hydra THV is a novel repositionable self-expanding system with supra-annular bovine pericardial leaflets. METHODS: The Hydra CE study was a premarket, prospective, multicenter, single-arm study conducted across 18 study centers in Europe and Asia-Pacific countries. The primary endpoint was all-cause mortality at 30 days. All endpoints were adjudicated by an independent clinical events committee. RESULTS: A total of 157 patients (79.2 ± 7.1 years of age, 58.6% female; Society of Thoracic Surgeons score 4.7 ± 3.4%) were enrolled. Successful implantation was achieved in 94.3% cases. At 30 days, there were 11 (7.0%) deaths, including 9 (5.7%) cardiovascular deaths, of which 5 (3.2%) were device related. At 1 year, there were 23 (14.6%) deaths, including 13 (8.3%) cardiovascular deaths. At 30 days, there were significant improvement of effective orifice area (from 0.7 ± 0.2 cm2 to 1.9 ± 0.6 cm2) and mean aortic valve gradient (from 49.5 ± 18.5 mm Hg to 8.1 ± 3.7 mm Hg), which were sustained up to 1 year. Moderate or severe paravalvular leak was observed in 6.3% of patients at 30 days and 6.9% of patients at 1 year. The rate of new permanent pacemaker implantation was 11.7% at 30 days and 12.4% at 1 year. CONCLUSIONS: The Hydra CE study demonstrated that transcatheter aortic valve replacement with Hydra THV offered favorable efficacy at 1 year, providing large effective orifice area and low transvalvular gradient as well as acceptable complication rates with regard to new permanent pacemaker and paravalvular leak. (A Clinical Evaluation of the HYDRA Self Expanding Transcatheter Aortic Valve; NCT02434263).

Pilot implementation of opioid stewardship measures using the national surgical quality improvement program-pediatric platform.

INTRODUCTION: Data surrounding optimal pediatric postoperative opioid prescribing are incomplete. The objective of this study was to leverage the American College of Surgeons (ACS) National Surgical Quality Improvement Program-Pediatric (NSQIP-P) and assess feasibility of added data collection surrounding pediatric perioperative pain management practices including opioid prescribing at discharge. METHODS: Nineteen (19) novel data elements were added to NSQIP-P data collection of selected patients, ages 5-18 years, who had undergone surgery at a single, free-standing children's hospital. Metrics around data abstraction and completion of variables were collected. Univariate analyses (using Chi-square or Wilcoxon Rank Sum tests) and multiple logistic regressions were performed to describe predictors of opioid prescribing at discharge and to monitor adherence to Food and Drug Administration (FDA) prescribing recommendations. RESULTS: Median abstraction time of the novel variables decreased from 12 to 5 min per patient over 13 months with 94% variable completion rate. Of 878 patients, 302 (36.4%) were prescribed opioids at discharge. Factors associated with an opioid prescription included older age (p < 0.001), white race (p < 0.05), undergoing an orthopedic surgery (p < 0.001), and receiving a regional block perioperatively (p < 0.001). All opioid prescriptions met FDA guidelines with no patients receiving codeine, and 98% of patients receiving opioid prescriptions < 50 morphine milli-equivalents per day. CONCLUSION: Collecting data on current pain management practices, opioid prescribing, and adherence to safety recommendations is feasible using the NSQIP-P with little added burden. Further expansion of data collection is needed to develop generalizable optimal prescribing practices for post-discharge pain management for children.

Patient and Clinician Perceptions of Informed Consent and Decision Making About Accepting KDPI > 85 Kidneys.

BACKGROUND: Although the impact of the kidney donor profile index (KDPI) on kidney discard is well researched, less is known about how patients make decisions about whether to give consent for KDPI > 85 kidney offers. METHODS: We conducted in-depth, semistructured interviews with 16 transplant recipients, 15 transplant candidates, and 23 clinicians (transplant surgeons, nephrologists, and nurse coordinators) to assess and compare perceptions of transplant education, informed consent for KDPI > 85 kidneys' and the decision-making process for accepting kidney offers. Thematic analysis was used to analyze qualitative data. RESULTS: Four themes emerged: (1) patients reported uncertainty about the meaning of KDPI or could not recall information about KDPI; (2) patients reported uncertainty about their KDPI > 85 consent status and a limited role in KDPI > 85 consent decision making; (3) patients' reported willingness to consider KDPI > 85 kidneys depended on their age, health status, and experiences with dialysis, and thus it changed over time; (4) patients' underestimated the survival benefit of transplantation compared with dialysis, which could affect their KDPI > 85 consent decision making. CONCLUSIONS: To better support patients' informed decision making about accepting KDPI > 85 kidneys, centers must ensure that all patients receive education about the trade-offs between accepting a KDPI > 85 kidney and remaining on dialysis. Additionally, education about KDPI and discussions about informed consent for KDPI > 85 kidneys must be repeated at multiple time points while patients are on the waiting list.

Implementation methodology from a social systems informatics and engineering perspective applied to a parenting training program.

OBJECTIVE: For implementation of an evidence-based program to be effective, efficient, and equitable across diverse populations, we propose that researchers adopt a systems approach that is often absent in efficacy studies. To this end, we describe how a computer-based monitoring system can support the delivery of the New Beginnings Program (NBP), a parent-focused evidence-based prevention program for divorcing parents. METHOD: We present NBP from a novel systems approach that incorporates social system informatics and engineering, both necessary when utilizing feedback loops, ubiquitous in implementation research and practice. Examples of two methodological challenges are presented: how to monitor implementation, and how to provide feedback by evaluating system-level changes due to implementation. RESULTS: We introduce and relate systems concepts to these two methodologic issues that are at the center of implementation methods. We explore how these system-level feedback loops address effectiveness, efficiency, and equity principles. These key principles are provided for designing an automated, low-burden, low-intrusive measurement system to aid fidelity monitoring and feedback that can be used in practice. DISCUSSION: As the COVID-19 pandemic now demands fewer face-to-face delivery systems, their replacement with more virtual systems for parent training interventions requires constructing new implementation measurement systems based on social system informatics approaches. These approaches include the automatic monitoring of quality and fidelity in parent training interventions. Finally, we present parallels of producing generalizable and local knowledge bridging systems science and engineering method. This comparison improves our understanding of system-level changes, facilitates a program's implementation, and produces knowledge for the field. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Clinical evaluation of the Hydra self-expanding transcatheter aortic valve: 6 month results from the GENESIS trial.

OBJECTIVES: To evaluate the safety and performance of the Hydra transcatheter aortic valve (THV) in the treatment of symptomatic severe aortic stenosis in patients at high or extreme surgical risk. BACKGROUND: The Hydra THV (Vascular Innovations Co. Ltd., Nonthaburi, Thailand) is a novel flexible repositionable self-expanding system with supra-annular bovine pericardial leaflets, available in three sizes, covering aortic annuli between 17 and 27 mm. METHODS: The GENESIS trial was a prospective, multi-center, single-arm, 6 month follow-up study conducted in India. The primary performance endpoint was device success defined as per VARC-II criteria at 30 days. The primary safety endpoint was all-cause mortality at 30 days. All endpoints were adjudicated by an independent clinical events committee. RESULTS: Forty high-risk patients (74.5 ± 6.7 years, 60% men; STS Score:5.6 ± 4.2%) were enrolled in 11 centres. Device success was achieved in 92.5%. The effective orifice area improved from 0.7 ± 0.2 to 2.3 ± 0.6 cm2 at 30 days and to 2.2 ± 0.7 cm2 at 6 months (p < .0001). Mean aortic valve gradient decreased from 53.5 ± 18.1 to 8.9 ± 4.9 mmHg at 30 days and to 7.6 ± 2.7 mmHg at 6 months (p < .0001). The rate of new permanent pacemaker implantation was 7.5% at 30 days, and no patient had more than mild paravalvular leak at 6 months. The 30 days and 6 month all-cause mortality was 10.0 and 17.5%, cardiovascular mortality 7.5 and 7.5%, device-related mortality 5.0 and 5.0%, respectively. No patients had stroke up to 6 months. CONCLUSIONS: The GENESIS trial demonstrated high efficacy of the self-expanding Hydra THV. The cardiovascular mortality rate of 7.5% may partly be explained by the inclusion of some centres with no or limited previous experience in transcatheter aortic valve implantation.

Predicting Kidney Discard Using Machine Learning.

BACKGROUND: Despite the kidney supply shortage, 18%-20% of deceased donor kidneys are discarded annually in the United States. In 2018, 3569 kidneys were discarded. METHODS: We compared machine learning (ML) techniques to identify kidneys at risk of discard at the time of match run and after biopsy and machine perfusion results become available. The cohort consisted of adult deceased donor kidneys donated between December 4, 2014, and July 1, 2019. The studied ML models included Random Forests (RF), Adaptive Boosting (AdaBoost), Neural Networks (NNet), Support Vector Machines (SVM), and K-nearest Neighbors (KNN). In addition, a Logistic Regression (LR) model was fitted and used for comparison with the ML models' performance. RESULTS: RF outperformed other ML models. Of 8036 discarded kidneys in the test dataset, LR correctly classified 3422 kidneys, whereas RF correctly classified 4762 kidneys (area under the receiver operative curve [AUC]: 0.85 versus 0.888, and balanced accuracy: 0.681 versus 0.759). For the kidneys with kidney donor profile index of >85% (6079 total), RF significantly outperformed LR in classifying discard and transplant prediction (AUC: 0.814 versus 0.717, and balanced accuracy: 0.732 versus 0.657). More than 388 kidneys were correctly classified using RF. Including biopsy and machine perfusion variables improved the performance of LR and RF (LR's AUC: 0.888 and balanced accuracy: 0.74 versus RF's AUC: 0.904 and balanced accuracy: 0.775). CONCLUSIONS: Kidneys that are at risk of discard can be more accurately identified using ML techniques such as RF.

Physician and patient acceptance of policies to reduce kidney discard.

Despite the shortage of kidneys for transplantation in the United States, approximately 18%-20% of deceased donor kidneys are discarded each year. These discarded kidneys can offer a survival benefit to suitable patients. Revisions to the current kidney allocation policy may be needed to reduce deceased donor kidney discard. We surveyed transplant physicians and patients to assess their perceived acceptability of policy proposals to reduce the discard of deceased donor kidneys. Members of professional societies (AST, ASTS) and a patient organization (AAKP) were invited to complete the survey. Responses were obtained from 97 physicians and 107 patients. The majority of physicians (73.4%) and patients (73.8%) "somewhat" or "completely" accepted a policy for fast-tracking kidneys at risk of discard. Physicians and patients also supported returning a proportion of waiting time to patients who accept KDPI >85 kidneys and experience graft failure within the first 12 months, with 36% of physicians and 50% of patients electing to return 100% of the waiting time. The majority of physicians (75%) "somewhat or completely" accepted a policy to skip less aggressive centers for KDPI 90 + offers. Physicians and patients provided insights into factors researchers, and policymakers should consider in the design and implementation of these policies.