Simultaneous Heart Kidney Research Articles

(1392) - Comparison of Basiliximab and Anti-Thymocyte Globulin as Induction Therapy for Simultaneous Heart-Kidney Transplantation in the Contemporary Era

(1392) - Comparison of Basiliximab and Anti-Thymocyte Globulin as Induction Therapy for Simultaneous Heart-Kidney Transplantation in the Contemporary Era

(537) - Comparative Outcomes of Simultaneous Heart-Kidney Transplantation from DBD and DDC-NRP Donors

(537) - Comparative Outcomes of Simultaneous Heart-Kidney Transplantation from DBD and DDC-NRP Donors

(24) - Bridge to Simultaneous Heart-Kidney Transplantation via Extracorporeal Life Support: National Outcomes in the New Heart Allocation Policy Era

(24) - Bridge to Simultaneous Heart-Kidney Transplantation via Extracorporeal Life Support: National Outcomes in the New Heart Allocation Policy Era

High Rate of Kidney Graft Failure after Simultaneous Heart-Kidney Transplantation.

The indications and outcomes of Simultaneous heart-kidney transplantation (SHKT) remain sub-optimally defined. Risk factors for renal graft failure after SHKT also remain poorly defined. We analyzed the renal graft outcomes among SHKT recipients using United Network for Organ Sharing database from 2015-2020. To evaluate for factors associated with poor renal outcomes, we compared SHKT and kidney transplantation alone (KTA) recipients using propensity score matching. Among SHKT recipients, rate of primary non-function (PNF) of kidney graft was 3%, 30-day kidney graft failure rate was 7.0%, and the 30-day post-transplant mortality rate was 4.1%. The incidence of delayed kidney graft function (KDGF) was 27.5%. Kidney graft failure was seen early post-SHKT with most common causes of patient death (43.9%) and PNF of kidney graft (41.5%). One-year and two-year patient survival was 89.2% and 86.5%, and one-year and two-year freedom from kidney graft failure was 85.4% and 82.7%, respectively. In subgroup analysis of SHKT recipients, use of pre-transplant mechanical cardiac support (adjusted Odds Ratio (aOR) 2.57, P=0.017), higher cPRA (aOR 1.76, P=0.016), and older donor age per 10 years (aOR 1.94, P=0.001) were associated with PNF. Pre-transplant extracorporeal membrane oxygenation support was associated with the increased risk of 30-day recipient mortality (aOR 5.55, P=0.002). Increased 30-day graft failure was seen in SHKT recipients with pre-transplant mechanical cardiac support (aOR 1.77, P=0.038) and dialysis at time of transplant (aOR 1.72, P=0.044). Multivariable Cox-Hazard analysis demonstrated that SHKT, when compared to KTA, is associated with increased kidney graft failure (Hazard Ratio, 2.56, P<0.001) and recipient mortality (Hazard Ratio: 2.65, P<0.001). SHKT is associated with high rates of kidney graft failure. Identification of risk factors for renal graft failure can help optimize recipient selection for SHKT vs Kidney after HT, especially after introduction of the new safety-net policy.

Outcomes of Simultaneous Heart-Kidney vs. Sequential Heart-Kidney Transplantation in Children

Outcomes of Simultaneous Heart-Kidney vs. Sequential Heart-Kidney Transplantation in Children

Simultaneous heart-kidney transplant compared with heart transplant alone in patients with borderline renal function who are not dialysis dependent

ObjectiveThis study assessed characteristics and outcomes of patients who are not dependent on dialysis receiving simultaneous heart kidney transplantation versus heart transplantation alone (HTA) to identify optimal eGFR threshold where combined transplant strategy may be superior. MethodsThis study retrospectively analyzed 7896 adult patients with estimated glomerular filtration rate (eGFR) <60 mL/minute from the United Network for Organ Sharing database who received HTA or simultaneous heart kidney transplant between 2005 and 2021, excluding those who received pretransplant dialysis. Subjects were further stratified into 3 groups based on chronic kidney disease stage at time of transplant: Stage 3A (eGFR 45-59 mL/minute; n = 5044), Stage 3B (eGFR 30-44 mL/minute; n = 2193), and Stage 4 or 5 (eGFR <30 mL/minute; n = 659). Outcomes of interest were all-cause mortality, cardiac allograft failure, and freedom from chronic dialysis or renal transplant following heart transplant. ResultsSimultaneous heart kidney transplant and HTA recipients differed in various baseline characteristics. Simultaneous heart kidney transplant recipients with eGFR <45 mL/minute had greater short- and long-term overall survival and cardiac allograft survival compared with HTA, as well as greater long-term freedom from chronic dialysis or renal transplant. These results were consistent with both propensity matched analyses and multivariable Cox regression analysis of 10 year outcomes. Optimal cutoff value for pretransplant eGFR in predicting elevated risk of renal failure in recipients of heart transplant alone was found to be eGFR ∼45 mL/minute. ConclusionsSimilar to patients with eGFR <30 mL/minute, patients with eGFR 30 to 44 mL/minute who underwent simultaneous heart kidney transplant had superior outcomes compared with HTA, suggesting possible benefit of combined transplant strategy for this subset of heart transplant candidates.

Survival After Simultaneous Heart-kidney Transplant in Recipients With a Durable LVAD and Chronic Kidney Disease: Effect of the 2018 Heart Allocation Policy Change.

Heart transplantation remains the most definitive therapy for qualified candidates with end-stage heart failure. Concomitant kidney disease is common in this population prompting an increase in simultaneous heart-kidney (SHK) transplantation in recent years. The goal of our study was to explore the effects of the 2018 heart allocation policy (HAP) change on candidate listing characteristics and compare survival rates at 1 y in patients that were supported with a left ventricular assist device (LVAD) pretransplant and underwent SHK or heart alone transplant (HAT). We used data from the Scientific Registry of Transplant Recipients and identified all adults who underwent primary SHK or HAT between January 2010 and March 2022. Recipients supported with a durable LVAD and estimated glomerular filtration rate <60 mL/min/1.73 m 2 were selected (n = 309 SHK; 217 pre- and 92 post-HAP and n = 3,324 HAT; 2738 pre- and 586 post-HAP). Difference in survival at 1 y did not reach statistical significance. Comparing the 1-y survival of SHK and HAT recipients who were bridged with LVAD pre-HAP, we found no significant difference ( P = 0.694). Adjusting for the same covariates in a multivariable model did not affect the results (SHK versus HAT hazard ratio 0.84 [0.51, 1.37]; P = 0.48). In contrast, SHK recipients supported with an LVAD who were listed and transplanted post-HAP change had significantly lower 1-y survival, when compared with HAT ( P = 0.037). Our findings suggest that the HAP change had a potentially negative impact on the survival of select patients undergoing SHK transplant. Further research is warranted in this area.

Do age and functional dependence affect outcomes of simultaneous heart–kidney transplantation?

ObjectiveThis study assessed characteristics and outcomes of younger (18-65) versus older (>65) recipients of simultaneous heart–kidney (SHK) transplantation with varying functional dependence. MethodsThis study retrospectively analyzed 1398 patients from the United Network for Organ Sharing database who received SHK between 2010 and 2021. Patients who were <18 year old, underwent transplant of additional organs simultaneously, or had previous heart transplant were excluded. The primary end point was all-cause mortality, and secondary end points included adverse events and cause of death. Outcomes were also evaluated by propensity score–matched comparison. ResultsThe number of annual SHK transplantation in the United States has significantly increased among both age groups over the past 2 decades (P < .0001). After propensity score matching of recipients aged 18 to 65 years (n = 1162) versus age >65 years (n = 236), baseline characteristics were similar and well-balanced between the 2 cohorts. Between matched cohorts, older recipients did not have increased posttransplant mortality compared with younger recipients (90-day survival, P = .85; 7-year survival, P = .61). Multivariable Cox regression analysis found that age (hazard ratio [HR], 1.039 [0.975-1.106], P = .2415) and pretransplant functional status with interaction term for age (some assistance, HR, 0.965 [0.902-1.033], P = .3079; total assistance, HR, 0.976 [0.914-1.041], P = .4610) were not significant risk factors for 7-year post-SHK transplantation mortality. ConclusionsOlder and more functionally dependent recipients in this study did not have increased post-SHK transplantation mortality. These findings have important implications for organ allocation among elderly patients, as they support the need for thorough assessment of SHK candidates in terms of comorbidities, rather than exclusion solely based on age and functional dependence.

Temporary Mechanical Circulatory Support Use and Clinical Outcomes of Simultaneous Heart/Kidney Transplant Recipients in the Pre- and Post-heart Allocation Policy Change Eras.

The use of temporary mechanical circulatory support (tMCS) devices (intra-aortic balloon pump; Impella 2.5, CP, 5.0; venoarterial extracorporeal membrane oxygenation) increased significantly across the United States for heart transplant candidates after the allocation policy change. Whether this practice change also affected simultaneous heart-kidney (SHK) candidates and recipient survival is understudied. We used the Scientific Registry of Transplant Recipients database to identify adult SHK recipients between January 2010 and March 2022. The population was stratified into pre- and post-heart allocation change cohorts. Kaplan-Meier curves were generated to compare 1-y survival rates. A Cox proportional hazards model was used to investigate the effect of allocation period on patient survival. Recipient outcomes bridged with eligible tMCS devices were compared in the post-heart allocation era. In a separate analysis, SHK waitlist mortality was evaluated between the allocation eras. A total of 1548 SHK recipients were identified, and 1102 were included in the final cohort (534 pre-allocation and 568 post-allocation change). tMCS utilization increased from 17.9% to 51.6% after the allocation change, with venoarterial extracorporeal membrane oxygenation use rising most significantly. However, 1-y post-SHK survival remained unchanged in the full cohort (log-rank P = 0.154) and those supported with any of the eligible tMCS devices. In a separate analysis (using a larger cohort of all SHK listings), SHK waitlist mortality at 1 y was significantly lower in the current allocation era ( P = 0.002). Despite the remarkable increase in tMCS use in SHK candidates after the heart allocation change, 1 y posttransplant survival remained unchanged. Further studies with larger cohorts and longer follow-ups are needed to confirm these findings.

Intraoperative Considerations and Management of Simultaneous Heart Kidney Transplantation

Patients with heart failure are prone to developing non-cardiovascular comorbidities throughout the course of their disease. In particular, renal impairment is widespread in this patient population. The number of heart-kidney transplants has increased significantly over the past 2 decades. Currently, there is no consensus on therapies for patients who may need dual-organ transplants. The optimal timing of dual-organ transplantation is still debated. The options for the timing of dual-organ transplants are simultaneous, staged, or delayed. In this manuscript, the authors review their institutional experience with the intraoperative management of simultaneous heart-kidney transplants (SHKT) and discuss their outcomes, including cardiac primary graft dysfunction (PGD) and renal delayed graft function (DGF). A total of 31 patients were included in the SHKT study group. Data analysis revealed that no patients required newly initiated mechanical circulatory support (MCS) post-operatively, and 11 of 31 patients were placed on renal replacement therapy within 7 days postoperatively. Patients who did have post-operative MCS were intra-aortic balloon pumps that were present before the transplant and then removed on postoperative day 1. No patient required additional MCS after the transplant. The increasing number of patients having heart and kidney transplants demonstrates a need for developing a perioperative management protocol. The results of our experience validate our intraoperative management. None of the patients developed moderate or severe cardiac PGD, and 35% had renal DGF. With further studies, the eventual development of guidelines for patient selection and management for SHKT also may be possible.

Prioritizing the Sickest Among the Sickest: A Matter of Tact and Moderation, but the Game Is Worth the Candle.

Prioritizing the Sickest Among the Sickest: A Matter of Tact and Moderation, but the Game Is Worth the Candle.

Heart–kidney transplant versus heart transplant in the obese: a propensity-matched analysis

The decision to perform simultaneous heart-kidneytransplant (HKT) rather than isolated heart transplant (IHT) for patients with advanced kidney disease is challenging. Limited data exist to guide this decision in obese patients. We sought to compare mortality after HKT and IHT in obese patients with non-dialysis-dependent kidney disease. The United Network for Organ Sharing was queried for data on adult heart transplant recipients from 2000 to 2022. Inclusion criteria were obesity, estimated glomerular filtration rate <45 ml/min/1.73 m2 and no pretransplant dialysis. HKT and IHT recipients were propensity matched. Morbidity was compared using chi-squared, Fisher's exact and McNemar's tests. Survival was assessed with Kaplan-Meier estimation. Risk factors for mortality were examined with Cox regression. A total of 289 HKT and 1920 IHT recipients met inclusion criteria. Heart-kidney recipients had higher baseline creatinine and rates of intensive care unit disposition than IHT recipients (both standardized mean differences >0.10). Propensity matching resulted in 239 pairs of HKT and IHT recipients with minimal differences in baseline characteristics. Heart-kidney recipients had higher 5- and 10-year survival than IHT recipients on unmatched (77% vs 69%, P = 0.011 and 58% vs 48%, P = 0.008) and propensity matched analyses (77% vs 68%, P = 0.026 and 57% vs 39%, P = 0.007). Heart-kidney transplantation was protective against 10-year mortality on multivariable regression (hazard ratio 0.585, P = 0.002). In obese patients with non-dialysis-dependent kidney disease, HKT may decrease long-term mortality relative to IHT and should be strongly considered as a preferred treatment.

Severely Reduced Kidney Function Assessed by a Single eGFR Determination at the Time of an Isolated Heart Transplant Does Not Predict Inevitable Posttransplant ESKD.

Consensus guidelines advise simultaneous heart kidney transplantation (SHK) in heart candidates with an estimated glomerular filtration rate (eGFR) of <30 mL/min/1.73 m 2 . We hypothesize that a significant fraction of such patients would not need an SHK, even though a graded increase in mortality and end-stage kidney disease (ESKD) would be seen with decrements in eGFR. United Network of Organ Sharing data for isolated heart transplants between 2000 and 2020 were divided into two groups based on eGFR at transplant (≤20 mL/min/1.73 m 2 and 21-29 mL/min/1.73 m 2 ). The primary outcome was mortality and secondary outcome was ESKD posttransplant. Cox regression and cumulative incidence competing risk methods were used to compare risk of mortality and ESKD. There was no difference in mortality (adjusted hazard ratio [aHR] 0.82 [95% confidence interval, CI: 0.60-1.11, P = 0.21]) or ESKD (aHR 1.01 [95% CI: 0.49-2.09, P = 0.96]) between the two groups (≤20 versus 21-29). The overall incidence of ESKD for the entire cohort at 1, 5, and 10 y were 1.5%, 9.5%, and 20%. Although risk of ESKD is highest in heart candidates with an eGFR <30 mL/min/1.73 m 2 , <10% of patients reach ESKD within 5 y' and most will recover significant renal function posttransplant. More refined selection criteria are required to identify candidates for SHK.

Outcomes in Patients With LVADs Undergoing Simultaneous Heart-Kidney Transplantation

Multiple studies have shown better outcomes for simultaneous heart-kidney transplant (sHKT) than for isolated orthotopic heart transplant (iOHT) in recipients with chronic kidney disease (CKD). However, outcomes in patients supported by durable left ventricular assist devices (LVADs) have not been well studied. Patients with durable LVADs and stage 3 or higher CKD (eGFR < 60 mL/min/1.73 m2) undergoing iOHT or sHKT between 2008 and 2020 were identified from the United Network for Organ Sharing registry. A Kaplan-Meier survival analysis with associated log-rank test was conducted to compare post-transplant survival rates. Multivariable modeling was used to identify risk-adjusted predictors of 1 year post-transplant mortality. We identified 4375 patients; 366 underwent sHKT, and 4009 underwent iOHT. The frequency of sHKT increased during the study period. The 1-year post-transplant survival rate was worse in patients after sHKT than in patients after iOHT (80.3% vs 88.3%; P < 0.001) and persisted up to 5 years post-transplant (P = 0.001). sHKT recipients were more likely to require dialysis after transplantation and had longer hospital lengths of stay (P < 0.001). Multivariable analysis showed that sHKT remained an independent risk factor for mortality at 1 year (OR 1.58; P = 0.002). sHKT is becoming more common in patients with durable LVADs. Compared with iOHT, patients with sHKTs have worse short- and long-term survival rates and are more likely to require post-transplant dialysis.

Predicting Post-Heart Transplant Composite Renal Outcome Risk in Adults: A Machine Learning Decision Tool

Predicting Post-Heart Transplant Composite Renal Outcome Risk in Adults: A Machine Learning Decision Tool

Optimal patient selection for simultaneous heart-kidney transplant: A modified cost-effectiveness analysis

Increasing rates of simultaneous heart-kidney (SHK) transplant in the United States exacerbate the overall shortage of deceased donor kidneys (DDK). Current allocation policy does not impose constraints on SHK eligibility, and how best to do so remains unknown. We apply a decision-analytic model to evaluate options for heart transplant (HT) candidates with comorbid kidney dysfunction. We compare SHK with a "Safety Net" strategy, in which DDK transplant is performed 6months after HT, only if native kidneys do not recover. We identify patient subsets for whom SHK using a DDK is efficient, considering the quality-adjusted life year (QALY) gains from DDKs instead allocated for kidney transplant-only. For an average-aged candidate with a 50% probability of kidney recovery after HT-only, SHK produces 0.64 more QALYs than Safety Net at a cost of 0.58 more kidneys used. SHK is inefficient in this scenario, producing fewer QALYs per DDK used (1.1) than a DDK allocated for KT-only (2.2). SHK is preferred to Safety Net only for candidates with a lower probability of native kidney recovery (24%-38%, varying by recipient age). This finding favors the implementation of a Safety Net provision and should inform the establishment of objective criteria for SHK transplant eligibility.

Simultaneous Heart-Kidney Transplant Outcomes Pre- and Post-Heart Allocation System Change: Impact of Temporary Mechanical Circulatory Support

<h3>Purpose</h3> The United Network for Organ Sharing (UNOS) changed the donor heart allocation system in October 2018 aiming to prioritize organ availability to candidates with the highest mortality risk. Following this change, the use of temporary mechanical circulatory support devices (tMCS) increased dramatically in transplant centers across the United States. However, the potential effect of this change remains unknown in patients undergoing simultaneous heart-kidney (SHK) transplantation. The aim of this study was to compare outcomes in SHK recipients before and after the allocation change. <h3>Methods</h3> We identified all SHK recipients from the Scientific Registry of Transplant Recipients who underwent transplantation between January 2016 and November 2019. Patients were stratified into pre- and post-heart allocation change groups based on the date of surgery. Kaplan-Meier curves were generated to compare 1-year outcomes by era. Subsequently, patients with the following tMCS devices were identified within each group: Intra-aortic balloon pump (IABP); Impella 2.5, CP, 5.0; Centrimag and VA-ECMO. Separate 1-year survival analyses were performed and compared between pre- and post-heart allocation change. <h3>Results</h3> We identified 400 and 138 patients who underwent SHK transplant pre- and post-heart allocation change, respectively. The overall 1-year survival rate of SHK recipients was lower after October 2018 (p=0.002; Figure 1A). 56 patients (14.1%) were transplanted with a tMCS device before and 65 (47.1%) after the allocation change. There was no significant difference in 1-year survival between the two groups (p=0.319; Figure 1B). <h3>Conclusion</h3> tMCS device use increased following the heart allocation change. Our results indicate that the one-year survival of SHK recipients has declined after the change, but it was independent of the increased tMCS device use. Further studies are needed to evaluate long-term outcomes.

Evaluation of Donor Glomerular Filtration Rate on Survival Outcomes among Simultaneous Heart and Kidney Transplant Recipients

Purpose Evaluation of donor co-morbidities is critical in order to risk-stratify and optimize post-transplant survival among simultaneous heart and kidney transplant (HKT) patients. We aimed to characterize the effect of donor glomerular filtration rates (GFR) on HKT recipient survival at 60 months post-transplantation. Methods All patients registered in the UNOS database who received HKT from 1/1/2010 - 6/1/2021 were analyzed. HKT recipients with donors of GFR >30 mL/min/1.73 m2 (n =1934) and donors with GFR <=30 mL/min/1.73 m2 (n = 59) were compared. HKT recipients with donors of GFR >60 mL/min/1.73 m2 (n=1611) and <=60mL/min/1.73 m2 (n=382) were also compared. Baseline characteristics were compared using Mann-Whitney U and Chi-square analyses. Mean age among all recipients was 55.8 years (SE 10.8). Comorbidities including diabetes, smoking, pre transplant dialysis requirements, donor age, use of ventricular assist devices, life support ventilators, intra-aortic balloon pumps, and ischemic time were similar among groups. Kaplan-Meier survival analysis was performed at 60 months post-transplantation. Results At 60 months post-transplant, there were no significant differences in survival among HKT patients with donor GFR <=60mL/min/1.73 m2 and donor GFR>60mL/min/1.73 m2 groups, respectively (p=0.858). At 60 months post transplant, there was no significant survival change among those with donor GFR <=30 mL/min/1.73 m2 and >30 mL/min/1.73 m2 (p=0.400). After adjusting for variables listed above, HKT recipients with donors of GFR <=60 compared to >60 had similar survival rates (adjusted HR 1.016, 95% CI 0.776-1.332, p=0.904). A similar trend was seen for patients with donors of GFR <= 30 mL/min/1.73 m2 compared to those of GFR >30 mL/min/1.73 m2 (adjusted HR 0.650, 95% CI 0.290-1.457, p=0.295). Conclusion Donor GFR in isolation had no significant impact on survival among simultaneous heart kidney transplant recipients at 60 months post transplantation after controlling for comorbidities. Donor kidney function In isolation should also not prohibit consideration for dual organ transplantation. Evaluation of donor co-morbidities is critical in order to risk-stratify and optimize post-transplant survival among simultaneous heart and kidney transplant (HKT) patients. We aimed to characterize the effect of donor glomerular filtration rates (GFR) on HKT recipient survival at 60 months post-transplantation. All patients registered in the UNOS database who received HKT from 1/1/2010 - 6/1/2021 were analyzed. HKT recipients with donors of GFR >30 mL/min/1.73 m2 (n =1934) and donors with GFR <=30 mL/min/1.73 m2 (n = 59) were compared. HKT recipients with donors of GFR >60 mL/min/1.73 m2 (n=1611) and <=60mL/min/1.73 m2 (n=382) were also compared. Baseline characteristics were compared using Mann-Whitney U and Chi-square analyses. Mean age among all recipients was 55.8 years (SE 10.8). Comorbidities including diabetes, smoking, pre transplant dialysis requirements, donor age, use of ventricular assist devices, life support ventilators, intra-aortic balloon pumps, and ischemic time were similar among groups. Kaplan-Meier survival analysis was performed at 60 months post-transplantation. At 60 months post-transplant, there were no significant differences in survival among HKT patients with donor GFR <=60mL/min/1.73 m2 and donor GFR>60mL/min/1.73 m2 groups, respectively (p=0.858). At 60 months post transplant, there was no significant survival change among those with donor GFR <=30 mL/min/1.73 m2 and >30 mL/min/1.73 m2 (p=0.400). After adjusting for variables listed above, HKT recipients with donors of GFR <=60 compared to >60 had similar survival rates (adjusted HR 1.016, 95% CI 0.776-1.332, p=0.904). A similar trend was seen for patients with donors of GFR <= 30 mL/min/1.73 m2 compared to those of GFR >30 mL/min/1.73 m2 (adjusted HR 0.650, 95% CI 0.290-1.457, p=0.295). Donor GFR in isolation had no significant impact on survival among simultaneous heart kidney transplant recipients at 60 months post transplantation after controlling for comorbidities. Donor kidney function In isolation should also not prohibit consideration for dual organ transplantation.

Center variations in patient selection for simultaneous heart-kidney transplantation.

Using the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research (STAR) file, we examined practice trends and variations in patient selection for SHK at the center level between January 1, 2004 and March 31, 2019. Overall, SHK is becoming more common with most centers performing heart transplants also performing SHK. Among patients who underwent heart transplant who were receiving dialysis, the rate of SHK varied from 22% to 86% at the center level. Among patients not on dialysis, the median estimated glomerular filtration rate (eGFR) of patients receiving SHK varied between 19 and 59 mL/min/1.73 m2 . When adjusting for other factors, the odds of SHK varied 57-fold between the highest and lowest SHK performing centers. Variation in SHK at the center level suggests the need for national guidelines around the selection of patients for SHK.

Abstract 12624: Optimal Patient Selection for Simultaneous Heart-Kidney Transplant: A Modified Cost-Effectiveness Analysis

Introduction: Increasing rates of simultaneous heart-kidney (SHK) transplant in the United States exacerbate the shortage of deceased donor kidneys (DDK) for kidney-only transplant (KT-only) candidates. Current allocation policy imposes no constraints on eligibility for SHK, and how best to do so remains unknown. Methods: We apply a decision analytic model to evaluate options for heart transplant (HT) candidates with comorbid kidney dysfunction, comparing 1) upfront SHK transplant (using a DDK) and 2) a “Safety Net” strategy, in which HT-only is performed first and DDK transplant is performed six months later if native kidneys do not recover. We measure “cost” in expected number of DDKs allocated to HT recipients, effectiveness in quality-adjusted life years (QALYs), and cost-effectiveness in terms of QALYs gained per kidney. We evaluate each outcome for patients of varying “reversibility”, defined as their probability of native kidney recovery after HT-only. We identify those for whom SHK (compared to Safety Net) is efficient from a societal standpoint, producing more QALYs per kidney than each additional kidney used for KT-only. Results: For a candidate with 50% reversibility, SHK (compared to Safety Net) produces 0.54 - 0.77 more QALYs (varying by age) at a cost of 0.58 more kidneys used. SHK is inefficient in this scenario, producing fewer QALYs per DDK (0.92 - 1.31) than an additional DDK allocated for KT-only (2.2 QALYs per kidney, derived from published estimates). SHK confers more benefit and is more cost-effective with decreasing age and reversibility, and is preferred to Safety Net for patients with reversibility under 24 - 38%. Conclusions: A Safety Net strategy produces greater societal benefit than SHK for HT candidates with concurrent kidney dysfunction, excepting only those with a low probability of native kidney recovery. This finding favors implementation of a Safety Net provision and should inform the use of objective criteria to limit SHK eligibility.