Faculty Bibliography

BACKGROUND:Despite the goal of the 2018 revision to the heart allocation policy to reduce reliance on exception requests through improved granularity in status criteria, there has been a dramatic rise in exception requests. OBJECTIVES/OBJECTIVE:This study evaluated trends in exception use over the first 6 years of the updated policy, assessing associated clinical factors, temporal changes, and impact on waitlist outcomes. METHODS:This retrospective transplant registry analysis included all adult isolated heart transplant candidates from October 18, 2018, to September 30, 2024. Candidates were stratified by exception use, listing era, and region. Exception use was compared using Wilcoxon rank-sum and chi-squared tests, with multilevel logistic regression assessing independent associations. Trends over time and across UNOS (United Network for Organ Sharing) regions were evaluated, and a competing risks framework examined time to transplant and waitlist mortality. RESULTS:Among 26,330 candidates, 38.6% used exception requests, with a statistically significant increase over time, particularly in higher priority statuses. Exception use was more common among Black, non-Hispanic candidates, and candidates with blood type O, and less likely for patients with blood type A (P < 0.001). Additionally, pretransplant isolated durable left ventricular assist devices were less common in candidates who requested exceptions (19.0% vs 31.6%; P < 0.001). Overall, 39.9% of exception candidates were listed at status 1 or 2 compared to 29% of nonexception candidates, and 69.2% of exception candidates were removed from the waitlist at status 1 or 2 compared with 37% of nonexception candidates. CONCLUSIONS:The rising use of exceptions underscores ongoing limitations in allocation criteria, and disparities suggesting inequities in access to higher listing status. Policy refinements are needed to ensure a balance between medical urgency and equitable allocation.

BACKGROUND:Transplant waitlist registrants in the United States may be delisted because of receipt of a transplant abroad. Although not universally unethical, "travel for transplantation" poses risks to posttransplant care. To better understand this phenomenon, this study identifies temporal trends, geographic patterns, and demographic factors associated with cross-border transplantation. METHODS:Using Scientific Registry of Transplant Recipients data, we identified 818 US waitlist candidates who were removed because of transplantation abroad between 2010 and 2023. We described recipient characteristics overall, by organ, and by top transplant destinations. We used a Cox regression framework to identify characteristics associated with waitlist removal due to transplantation abroad. RESULTS:Transplants abroad averaged 58.4 per year. Incidence peaked at 80 transplants in 2017, with an upward trend after 2021. Kidney transplants made up 92.1% of cases. The most common destinations were the Philippines (19.8%), India (16.5%), Mexico (9.4%), China (8.4%), and Iran (4.4%). India and Mexico experienced the smallest drop-off during the height of the COVID-19 pandemic 2020-2021. Most recipients were US citizens (65.0%) or residents (23.5%). Female (adjusted hazard ratio [aHR], 0.520.610.71; P < 0.001) and Black candidates (aHR, 0.120.180.26; P < 0.001) were less likely to travel abroad compared with Asian candidates (aHR, 5.927.108.52; P < 0.001). Nonresidents (aHR, 6.708.6911.26; P < 0.001) and, among registrations in 2012 or later, nonresidents who traveled to the United States for transplantation (aHR, 27.2738.9155.50; P < 0.001) had a greater chance of undergoing transplantation abroad. CONCLUSIONS:Understanding patterns of international travel for transplantation is key not only for preventing resource drains from destination countries but also for providing adequate posttransplant care for recipients.

OBJECTIVE:Given frailty and comorbidities that occur with both aging and end-stage kidney disease (ESKD), it is unclear if older patients with ESKD derive the improved survival and kidney transplant (KT) access associated with Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). METHODS:Using 2006-2021 USRDS data, we identified 876 patients with RYGB and 1508 patients with SG and compared 5-year mortality by age-group (18-29/30-39/40-49/50-59/60-69/≥ 70 years) to nonsurgical matched controls using 1:3 Mahalanobis distance matching, Kaplan-Meier, and Cox regression. We also compared age-stratified KT incidence between waitlisted patients and controls. RESULTS:) for patients with SG versus controls. CONCLUSIONS:RYGB in older patients with ESKD is associated with increased mortality and lower KT likelihood, whereas SG is associated with decreased mortality and higher KT likelihood compared to nonsurgical matched controls. Choice of bariatric surgery type may play a role in improving survival for older patients with ESKD.

INTRODUCTION/BACKGROUND:The United States Organ Procurement and Transplantation Network mandates collection of 6-month, 1-year, and 2-year post-donation follow-up data on living kidney donors (LKDs), but many centers struggle to meet these requirements. This study investigated whether providing a financial incentive (mailed gift card) could increase patient compliance with LKD follow-up. METHODS:A parallel, non-blinded, 1:1 superiority randomized control trial of LKDs was conducted at two centers from March 2017 to February 2021. The control arm received standard of care (SOC): instructions to complete the mandated LKD follow-up consisting of a health questionnaire and laboratory measurements at 6 months, 1 year, and 2 years post-donation. The intervention arm received SOC and was mailed a $25 gift card for each timely completed follow-up. Compliance rates were compared at each timepoint using Poisson regression. RESULTS:at 2 years). Similarly, no differences were observed in compliance with clinical follow-up, laboratory follow-up, or individual questions or lab values. CONCLUSION/CONCLUSIONS:Mailed gift cards did not improve patient compliance with LKD follow-up requirements; such interventions may be counterproductive among LKDs. Further research is needed to investigate and address barriers to completing LKD follow-up. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov identifier: NCT03090646.

We sought to understand the potential impacts of a rapidly evolving donor pool on the annual recalibration of the kidney donor profile index (KDPI). Using OPTN data, we examined the kidney donor risk index (KDRI) among deceased kidney donors recovered 2011-2024. We mimicked the OPTN's annual re-mapping process to measure the KDRI-to-KDPI calibration drift and used Cox regression to translate this drift into all-cause graft failure rate differences. The 50th/75th/95th KDRI percentile among recovered donors rose from 1.19/1.47/2.0 in 2011 to 1.40/1.77/2.36 in 2024. For donors with the same KDRI, the KDPI assigned in 2024 was as much as 13 points lower than the KDPI assigned in 2012. Holding other factors constant, the KDRI-KDPI calibration shift equated to 7 years of increased age (65 vs. 58) for KDPI 86% donors. Five-year graft failure risk was 9% higher (RR: _1.0871.093_1.097) for a kidney assigned a KDPI of 86% in 2024 versus 2012. Organ recovery practices have changed. The relationship between KDPI and organ quality has become a moving target, complicating shared decision-making and altering the meaning of allocation policy thresholds. Alternative solutions to annually remapping KDPI, such as establishing a fixed reference cohort or migrating away from KDPI, could be considered.

Procurement biopsies are routinely obtained in the United States to evaluate kidneys considered for transplantation, but some argue that they may contribute to kidney nonutilization. Historically, biopsy decisions have been left solely to the discretion of organ procurement organizations (OPOs) and transplant centers. In September 2022, an organ procurement and transplantation network (OPTN) policy designating donors meeting specific clinical criteria as "biopsy-required" went into effect. Using OPTN data from 1 year before and after policy implementation, we used causal inference methods to estimate the policy's impacts on biopsy practices and kidney utilization. The overall biopsy rate remained stable at 62%, rising from 90.6% to 95.8% (P < .001) among biopsy-required kidneys while falling from 49.1% to 43.4% (P < .001) among biopsy-optional kidneys. After adjusting for changing donor characteristics, the policy was associated with a 5% decline in the biopsy rate (adjusted risk ratio = 0.95; P = .007). The overall kidney nonuse rate rose from 27.2% to 28.7%. After accounting for changes in donor characteristics, the policy was not associated with elevated nonuse (adjusted risk ratio = 0.96, P = .06). Although most OPOs are now biopsying nearly all required kidneys, practices still vary widely regarding biopsy-optional kidneys. No correlation was found between OPO-level changes in adjusted biopsy and nonuse rates (ρ = 0.05, P = .70). The OPTN policy has partially standardized biopsy practices without harming kidney utilization.

BACKGROUND:Under the HOPE Act, transplants from donors with HIV to recipients with HIV (HIV D+/R+) have been largely limited to kidney and liver. However, recent modifications to HOPE research guidelines allow broader participation of cardiothoracic programs. METHODS:To quantify potential cardiothoracic HOPE donors, we used SRTR data (3/2016-12/2024) to identify 101,200 donors without HIV and 273 HOPE donors (with true and false positive HIV tests). Using logistic regression, we predicted the probability of having a heart or lung(s) used for transplant among donors without HIV that had a kidney or liver used. We then applied model parameters to HOPE donors that had a kidney or liver used to estimate the number of HOPE donors that might have been cardiothoracic donors if the practice were expanded. RESULTS:Among donors without HIV, cardiothoracic donation was associated with age, cause of death, hepatitis C, hypertension, diabetes, smoking, cardiovascular disease, blood gas, and circulatory death. Applying our model, an estimated 41.0% (N=111), 18.7% (N=51), and 15.2% (N=41) of HOPE donors were potential heart, any lung (single or double), or double-lung donors, as compared to 32.3%, 21.8%, and 18.2% of abdominal organ donors without HIV, respectively. This translated to an annual 13-18 potential heart and 5-8 potential lung transplants (of which 4-6 would be double-lung transplants) from HOPE donors. CONCLUSIONS:If HIV D+/R+ is more widely expanded to cardiothoracic transplantation, 41% of HOPE kidney and liver donors have potential to donate a heart and almost 20% to donate a lung to candidates with HIV.