Center Volume Predicts Improved Early Outcomes in Multiorgan Heart Transplantation.

PURPOSE: Center volume is associated with improved survival after isolated heart transplant, but its impact on multiorgan heart transplant (MHT) outcomes is unknown. This study examines the impact of institutional MHT volume on MHT outcomes. METHODS: Adult patients undergoing first time MHT from 2011 to 2021 were identified in the United Network for Organ Sharing database. Transplant centers were annually classified as low-, medium-, or high-volume if they performed <3, 3 to 5, or ≥6 MHTs that year, respectively. Graft failure was defined as death, failure, or re-transplantation of any allograft. RESULTS: A total of 1860 MHTs were performed at 104 centers, including 482 (26%) at low-, 601 (32%) at medium-, and 777 (42%) at high-MHT volume centers. Noncardiac allografts included kidney (83%), liver (16%), and lung (2%). The proportion of MHTs performed at high-volume centers increased from 10% in 2011 to 62% in 2021. Recipient age, race, and body mass index did not vary by center volume (all P > .05). Patients at high-volume centers were more likely to be in the intensive care unit pre-transplant (58% vs 44%, P < .001) and have shorter waitlist times (47 vs 92 days, P < .001) than those at low-volume centers. 30-day graft survival was higher in combined medium- and high-volume compared with low-volume centers (95% vs 92%, P = .004). Increasing center MHT volume was protective against 30-day graft failure (adjusted hazard ratio 0.93 [0.88-0.98]) on multivariate Cox regression. CONCLUSIONS: Higher MHT volume is associated with improved early graft survival after MHT, which may justify centralizing the performance of MHTs to high-volume centers.

Heart Retransplantation Under the 2018 Adult Heart Allocation Policy.

BACKGROUND: The purpose of the present study was to characterize the impact of the 2018 adult heart allocation policy change on waiting list and posttransplant outcomes of heart retransplantation in the United States. METHODS: All adults listed for heart retransplantation from May 2015 to June 2022 were identified using the United Network for Organ Sharing database. Patients were stratified into eras (era 1 and era 2) based on the heart allocation change on October 18, 2018. Competing risks regressions and Cox proportional hazards models were used to assess differences across eras in waiting list outcomes and 1-year posttransplant survival, respectively. RESULTS: The analysis included 356 repeat heart transplant recipients, with 207 (58%) receiving retransplantation during era 2. Patients who received a retransplant in era 2 were more commonly bridged with extracorporeal membrane oxygenation (21% vs 8%, P < .01) and intra-aortic balloon pump (29% vs 13%, P < .001) and had a lower likelihood of death/deterioration on the waiting list (subdistribution hazard ratio, 0.52; 95% CI, 0.33-0.82) compared with those in era 1. Rates of 30-day mortality (7% vs 7%, P = .99) and 1-year survival (82% vs 87%, P = .27) were not significantly different among retransplantation recipients across eras. After adjustment, retransplantation in era 2 was not associated with an increased hazard of mortality (adjusted hazard ratio, 1.13; 95% CI, 0.55-2.30). The gap in 1-year mortality between primary transplant and retransplant recipients increased from era 1 to 2. CONCLUSIONS: Heart retransplantation candidates have experienced improved waiting list outcomes after the 2018 adult heart allocation policy, without significant changes to posttransplant survival.

Non-inferior outcomes in lower urgency patients transplanted with extended criteria donor hearts.

BACKGROUND: Recent work has suggested that outcomes among heart transplant patients listed at the lower-urgency (United Network for Organ Sharing Status 4 or 6) status may not be significantly impacted by donor comorbidities. The purpose of this study was to investigate outcomes of extended criteria donors (ECD) in lower versus higher urgency patients undergoing heart transplantation. METHODS: The United Network for Organ Sharing (UNOS) database was queried for all adult patients undergoing heart transplantation from October 18, 2018 through December 31, 2021. Patients were stratified by degree of urgency (higher urgency: UNOS 1 or 2 vs lower urgency: UNOS 4 or 6) and receipt of ECD hearts, as defined by donor hearts failing to meet established acceptable use criteria. Outcomes were compared using propensity score matched cohorts. RESULTS: Among 9,160 patients included, 2,320 (25.4%) were low urgency. ECD hearts were used in 35.5% of higher urgency (HU) patients and 39.2% of lower urgency (LU) patients. While ECD hearts had an impact on survival among high-urgency patients (p < 0.01), there was no difference in 1- and 2-year survival (p > 0.05) found among low urgency patients receiving ECD versus standard hearts. Neither ECDs nor individual ECD criteria were independently associated with mortality in low urgency patients (p > 0.05). CONCLUSIONS: Post-transplant outcomes among low urgency patients are not adversely affected by receipt of ECD vs. standard hearts. Expanding the available donor pool by optimizing use of ECDs in this population may increase transplant frequency, decrease waitlist morbidity, and improve postoperative outcomes for the transplant community at large.

Short stature is a risk factor for heart transplant morbidity and mortality.

BACKGROUND: Short stature is associated with mortality after cardiac surgery and may increase size mismatch risk among transplant recipients. Yet, stature's impact on heart transplant outcomes is not well-characterized. METHODS: The Scientific Registry of Transplant Recipients was queried for data on all adult heart transplants in the United States from 2000 to 2022. Recipients were stratified into five cohorts by sex-corrected stature. Morbidity was assessed with Kruskal-Wallis and chi-squared tests. Mortality was analyzed using Kaplan-Meier estimation. Risk factors for mortality were assessed with multivariable Cox regression. RESULTS: Among 43,420 transplant recipients, 5321 (12.2%) had short stature (females >4'11″ & ≤5'1″; males >5'4″ & ≤5'7″) and 765 (1.8%) had very short stature (females ≤4'11″; males ≤5'4″). Very short stature patients had higher waitlist status (1A and 1), more congenital heart disease, and received more oversized donor hearts than other cohorts (all p < 0.05). Very short stature patients had decreased 30-day, 1-, 5-, and 10-year survival (94.6%, 84.3%, 69.3% and 52.5%, respectively, all p < 0.001), but less acute rejection (p = 0.005) and comparable stroke rates (p = 0.107). On multivariable regression adjusting for congenital heart disease and oversized donor hearts, very short and short stature were associated with 10-year mortality (hazard ratios: 1.40 and 1.12, respectively, both p < 0.005). CONCLUSIONS: Short stature confers increased mortality risk for heart transplant recipients and merits inclusion in prognostic models.

Decreased survival of simultaneous heart-kidney transplant recipients in the new heart allocation era.

BACKGROUND: In 2018, the United Network for Organ Sharing (UNOS) modified their heart allocation policy to reduce waitlist mortality. The rates of simultaneous heart-kidney transplant (SHKT) have dramatically increased in recent years, despite increased rates of posttransplant renal failure in the new policy era. This study sought to investigate the impact of the new allocation system on waitlist and posttransplant outcomes of simultaneous heart-kidney transplantation. METHODS: Adult patients listed for SHKT between 2012 and 2021 were included. Patients were cross-validated across both Thoracic and Kidney UNOS databases to confirm accurate listing and transplant data. Patients were stratified according to listing era. The Fine and Gray model was used to assess waitlist outcomes and posttransplant renal graft function. Kaplan-Meier analysis and Cox regression were used to compare posttransplant survival. RESULTS: A total of 2,588 patients were included, of whom 1,406 (54.1%) were listed between 2012 and 2018 (era 1) and 1,182 (45.9%) between 2019 and 2021 (era 2). Era 2 was associated with increased likelihood of transplant (adjusted Sub-hazard ratios (aSHR): 1.52; p < 0.01) and decreased waitlist mortality (aSHR: 0.63; p < 0.01). Posttransplant survival at 2 years was decreased in era 2 (78.8% vs 86.9%; p < 0.01). Undersized hearts (hazard ratio [HR]: 2.02; p < 0.01), use of extracorporeal membrane oxygenation (HR: 2.67; p < 0.1), and transplants performed following the policy change (HR: 1.45; p = 0.03) were associated with increased mortality. Actuarial survival (combined waitlist and posttransplant) was significantly lower in the modern era (71.6% vs 62.2%; p = 0.02). CONCLUSIONS: The allocation policy change has improved waitlist outcomes in patients listed for SHKT but potentially at the cost of worsened posttransplant outcomes.

Emerging Racial Differences in Heart Transplant Waitlist Outcomes for Patients on Temporary Mechanical Circulatory Support.

Temporary mechanical circulatory support (tMCS) is increasingly used for patients awaiting heart transplantation. Although examples of systemic inequity in cardiac care have been described, biases in tMCS use are not well characterized. This study explores the racial disparities in tMCS use and waitlist outcomes. The United Network for Organ Sharing database was used to identify adults listed for first-time heart transplantation from 2015 to 2021. White and non-White patients on extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary left ventricular assist device were identified. Waitlist outcomes of mortality, transplantation, and delisting were analyzed by race using competing risks regression. The effect of the new heart allocation system was also assessed. A total of 16,811 patients were included in this study, with 10,377 self-identifying as White and 6,434 as non-White. White patients were more often male, privately ensured, and had less co-morbidities (p <0.05). tMCS use was found to be significantly higher in non-White patients (p <0.001). Among those on tMCS, non-White patients were more likely to be delisted because of illness (subhazard ratio 1.34 [1.09 to 1.63]) and less likely to die while on the waitlist (subhazard ratio 0.76 [0.61 to 0.93]). This disparity was not present before the implementation of the new heart allocation system. tMCS use was proportional to the risk factors identified in the non-White cohort. After the implementation of the new heart allocation system, White patients were more likely to die, whereas non-White patients were more likely to be delisted. Further work is needed to determine the causes of and potential solutions for disparities in the waitlist outcomes.

Impella 5.5 as a bridge to heart transplantation: Waitlist outcomes in the United States.

OBJECTIVES: The 2018 United Network for Organ Sharing allocation policy change has led to a significant increase in the use of mechanical circulatory support devices in patients listed for orthotopic heart transplantation. However, there has been a paucity of data regarding the newest generation Impella 5.5, which received FDA approval in 2019. METHODS: The United Network for Organ Sharing registry was queried for all adults awaiting orthotopic heart transplantation who received Impella 5.5 support during their listing period. Waitlist, device, and early post-transplant outcomes were assessed. RESULTS: A total of 464 patients received Impella 5.5 support during their listing period with a median waitlist time of 19 days. Among them, 402 (87%) patients were ultimately transplanted, with 378 (81%) being directly bridged to transplant with the device. Waitlist death (7%) and clinical deterioration (5%) were the most common reasons for waitlist removal. Device complications and failure were uncommon (<5%). The most common post-transplant complication was acute kidney injury requiring dialysis (16%). Survival at 1-year post-transplant survival was 89.5%. CONCLUSION: Since its approval, the Impella 5.5 has been increasingly used as a bridge to transplant. This analysis demonstrates robust waitlist and post-transplant outcomes with minimal device-related and postoperative complications.

Aortic valve replacement for moderate aortic stenosis during mitral surgery improves survival free from severe stenosis.

BACKGROUND: Optimal management of moderate aortic stenosis during surgery for another indication is unclear. We assessed the effects of surgical aortic valve replacement for moderate aortic stenosis during mitral surgery. METHODS: An institutional mitral surgery database was queried for patients with preoperative moderate aortic stenosis. Patients were stratified by whether they underwent concomitant surgical aortic valve replacement. Morbidity was analyzed using Student's t tests, Wilcoxon rank sum, chi-squared, and Fisher's exact tests. Survival was analyzed using Kaplan-Meier estimation and Cox regression. RESULTS: Of 85 mitral surgery recipients with moderate aortic stenosis from 2012 to 2019, 62 (73%) underwent concomitant surgical aortic valve replacement. Surgical aortic valve replacement recipients were more likely to have bicuspid (11% vs. 0%, p = 0.019) or rheumatic (18% vs. 0%, p = 0.019) aortic valves, and to undergo mitral repair (32% vs. 9%, p = 0.028). Groups did not differ with respect to mitral etiology, New York Heart Association class, or cardiac intervention history (p > 0.05). Postoperatively, groups had similar stroke and gastrointestinal bleed rates (3% vs. 0% and 2% vs. 0% in the surgical aortic valve replacement vs. no surgical aortic valve replacement group respectively, both p > 0.99). Five-year survival free from severe aortic stenosis was higher in the surgical aortic valve replacement group (66% vs. 17%, p = 0.002). Surgical aortic valve replacement protected against the composite of death and progression to severe aortic stenosis at 5 years (hazard ratio: 0.32, p = 0.003). CONCLUSIONS: Surgical aortic valve replacement for moderate aortic stenosis at time of mitral surgery is a well-tolerated strategy to reduce aortic disease progression.

Outcomes of COVID-19-Positive Donor Heart Transplantation in the United States.

Background Little is known regarding the impact of donor COVID-19 status on recipient outcomes after heart transplantation. In this study, we characterize outcomes of the first 110 heart transplants from organ donors positive for COVID-19 (COVID-19+) in the United States. Methods and Results Retrospective analysis of the United Network for Organ Sharing database was performed for single-organ adult heart transplants from January 2020 to March 2022. Donor COVID-19+ status was defined as a positive nucleic acid amplification, antigen, or other COVID-19 test within 7 days of transplant. Nearest-neighbor propensity score matching used to adjust for differences between recipients of COVID-19+ and nonpositive donor hearts. Overall, 7251 heart transplants were included in analysis, with 110 using COVID-19+ donor hearts. Recipients of COVID-19+ allografts were younger (54 [interquartile range, 41-61]) versus 57 [46-64] years; P=0.02) but had similar rates of female sex and non-White race compared with those receiving allografts from negative donors. Nearest-neighbor propensity score matching resulted in 100 well-matched pairs of recipients of COVID-19+ versus nonpositive donor organs. The 2 matched groups had similar median lengths of stay (15 [11-23] days versus 15 [13-23] days; P=0.40), rates of graft failure (1% versus 0%; P=0.99), 30-day death (3% versus 3%; P=0.99), and 3-month survival (88% versus 94%; P=0.23) compared with recipients of nonpositive donors. No deaths occurred due to COVID-19 infection among the 8 (7%) total deceased recipients of COVID-19+ allografts to date. Conclusions Short-term outcomes of heart transplant recipients receiving COVID-19+ donor organs are reassuring. However, continued monitoring for long-term survival and potential complications are warranted.

Comparison of Intraaortic Balloon Pump and Impella 5.5 as Heart Transplant Bridging Strategies.

BACKGROUND: Temporary mechanical circulatory support is increasingly utilized as a bridge to heart transplantation. The Impella 5.5 (Abiomed) has achieved anecdotal success as a bridge since receiving US Food and Drug Administration approval. The purpose of the current study was to compare waitlist and posttransplant outcomes of patients bridged with intraaortic balloon pumps (IABPs) to those receiving Impella 5.5 therapy. METHODS: Patients listed for heart transplantation between October 2018 and December 2021 who received IABP or Impella 5.5 at any time during waitlist course were identified from the United Network for Organ Sharing database. Propensity-matched groups of recipients with each device were created. Competing-risks regression for mortality, transplantation, and removal from waitlist for illness was performed according to the method of Fine and Gray. Posttransplant survival was censored at 2 years. RESULTS: Overall, 2936 patients were identified, of whom 2484 (85%) were supported with IABP and 452 (15%) received Impella 5.5. Patients with Impella 5.5 support had more functional impairment, higher wedge pressures, higher rates of preoperative diabetes and dialysis, and more ventilator support (all P < .05). Waitlist mortality was significantly worsened in the Impella group and transplantation was less frequent (P < .001). However, survival at 2 years after transplant was similar in both complete (90% vs 90%, P = .693) and propensity-matched cohorts (88% vs 83%, P = .874). CONCLUSIONS: Patients bridged with Impella 5.5 were sicker than IABP-bridged patients and less frequently transplanted; however, posttransplant outcomes were similar in propensity-matched cohorts. The role of these bridging strategies in patients listed for heart transplantation should be continually assessed with future allocation system changes.

Prosthesis Choice in Dialysis Patients Undergoing Mitral Valve Replacement.

BACKGROUND: Patients with renal disease on dialysis have significant comorbidity limiting life expectancy; however, these patients may experience accelerated prosthetic valve degeneration. The purpose of this study was to examine the impact of prosthesis choice on outcomes in dialysis patients undergoing mitral valve replacement (MVR) at our high-volume academic center. METHODS: Adults undergoing MVR were retrospectively reviewed between January 2002 and November 2019. Patients were included if they had documented renal failure and dialysis requirements before presentation. Patients were stratified by mechanical vs bioprosthetic prosthesis. Death and recurrent severe valve failure (3+ or greater) or redo mitral operation were used as primary outcomes. RESULTS: There were 177 dialysis patients identified who underwent MVR. Of these, 118 (66.7%) received bioprosthetic valves, whereas 59 (33.3%) received mechanical valves. Those who received mechanical valves were younger (48 vs 61 years; P < .001) and had less diabetes (32% vs 51%; P = .019). Prevalence of endocarditis and atrial fibrillation was similar. Postoperative length of stay was not different between groups. Risk-adjusted hazard for 5-year mortality was similar between groups (P = .668). Early mortality was high, with both groups having <50% actuarial survival at 2 years. No differences were noted in rates of structural valve deterioration or reintervention. More stroke events were noted on follow-up in patients receiving mechanical valves (15% vs 6%; P = .041). Endocarditis was the leading reason for reintervention; 4 patients received repeated surgery for bioprosthetic valve failure. CONCLUSIONS: MVR in dialysis patients carries significant morbidity and increased midterm mortality. Decreased life expectancy should be considered in the tailoring of prosthesis choice to dialysis-dependent patients.

Extended criteria donor organ use for heart-lung transplantation in the modern era.

BACKGROUND: Demand for donor hearts and lungs exceeds their supply. Extended Criteria Donor (ECD) organs are used to help meet this demand, but their impact on heart-lung transplantation outcomes is poorly characterized. METHODS AND RESULTS: The United Network for Organ Sharing was queried for data on adult heart-lung transplantation recipients (n = 447) from 2005‒2021. Recipients were stratified based on whether they received ECD hearts and/or lungs. Morbidity was analyzed using Kruskal-Wallis, chi-square, and Fisher's exact tests. Mortality was analyzed using Kaplan-Meier estimation, log-rank tests and Cox regression. Sixty-five (14.5%) patients received two ECD organs, 134 (30.0%) received only an ECD lung, and 65 (14.5%) only an ECD heart. Recipients of two ECD organs were older, more likely to have diabetes, and more likely transplanted from 2015‒2021 (p < 0.05). Groups did not differ by pre-transplant diagnosis, intensive care unit disposition, life support use, or hemodynamics. Group five-year survival rates ranged from 54.5% to 63.2% (p = 0.428). Groups did not differ by 30-day mortality, strokes, graft rejection, or hospital length of stay. CONCLUSIONS: Using ECD hearts and/or lungs for heart-lung transplantation is not associated with increased mortality and is a safe strategy for increasing donor organ supply in this complex patient population.

Use of extended criteria donor hearts in combined heart-kidney transplant confers greater risk of mortality.

BACKGROUND: Extended criteria donors (ECD) hearts have demonstrated acceptable outcomes in select populations. However, their use in patients undergoing simultaneous heart-kidney transplantation (SHKT) has not been explored. This study is assessed the effect of ECD hearts in patients undergoing SHKT vs isolated heart transplants (IHT). METHODS: The United Network for Organ Sharing (UNOS) database was queried for all adult patients undergoing IHT and SHKT. Patients were stratified by receipt of ECD heart, defined as donor hearts failing to meet established acceptable use criteria. Interaction effects between ECDs and simultaneous kidney transplants were generated. Postoperative outcomes, risk factors, and patient/graft survival were compared across cohorts using Fine-Gray, Kaplan Meier, and Cox Proportional Hazards analyses. RESULTS: Among 26,207 patients included, 1,766 (7%) underwent SHKT. ECD hearts were used in 25% of both IHT and SHKT cohorts. Five-year survival among SHKT/ECD patients (67.3%) was reduced (p < 0.01) compared to SHKT/SDC (80.3%), IHT/ECD (78.1%) and IHT/SCD (80.0%) groups. Among SHKT patients, use of ECD hearts was associated with increased risk (SHR: 1.48; p < 0.01) of renal graft failure compared to SCD hearts. Among SHKT patients, receipt of an ECD heart, and individual ECD criteria (coronary disease and size mismatch >20%), predicted mortality. The interaction effect of receiving both ECD and SHKT predicted mortality and graft failure (HR 1.43; p < 0.01). CONCLUSIONS: Patients undergoing SHKT with an ECD heart face greater risks of mortality and graft failure in comparison to those undergoing IHT with ECD hearts. Careful selection of donor organs should be applied to this high-risk cohort.

Waitlist Trends in Heart-Liver Transplantation With Updated US Heart Allocation System.

BACKGROUND: In October 2018, the United States implemented a change in the donor heart allocation policy from a three-tiered to a six-tiered status system. The purpose of the current study was to examine changes in waitlist patterns among patients listed for concomitant heart-liver transplantation with implementation of the new allocation system. METHODS: Patients listed for heart-liver transplantation between January 1, 2012, and June 30, 2021, were identified from the United Network for Organ Sharing database. Patients were grouped by era according to initial list date before or after October 18, 2018. Competing risks regression for mortality, transplantation, removal from waitlist due to illness was performed according to the method of Fine and Gray. Waitlist data were censored at 3 years from initial listing. RESULTS: Overall, 523 patients were identified, of whom 310 were listed before (era 1, 59%) and 213 after (era 2, 41%) allocation change. Patients in era 1 were older, had more restrictive cardiomyopathy, and more preoperative inotrope use (all P < .05). However, patients in era 2 has longer ischemic times (3.5 ± 1.1 vs 3.1 ± 1.1 hours, P < .01) and more intraaortic balloon pump use (8.9% vs 3.9%, P = .016). Era 2 was associated with lower subdistribution hazard for death (hazard ratio 0.37; 95% CI, 0.13-1.02; P = .054) and increased transplantation (hazard ratio 1.35; 95% CI, 1.06-1.72; P = .015). CONCLUSIONS: The implementation of the US donor heart allocation policy was associated with more preoperative intraaortic balloon pump use for patients listed for heart-liver transplantation. Despite that, the modern era was associated with lower waitlist mortality and more frequent transplantation, without increased risk of delisting due to illness.

Tricuspid surgery at time of mitral surgery improves survival free from severe tricuspid regurgitation but not quality of life.

Objective: The choice to operate on moderate tricuspid regurgitation (TR) during mitral surgery is challenging owing to limited mid-term data. We assess whether concomitant tricuspid operations improve mid-term quality of life, morbidity, or mortality. Methods: An institutional database identified mitral surgery recipients with moderate TR at the time of surgery from 2010 to 2019. Patients were stratified by the presence of a concomitant tricuspid operation. Quality of life at the last follow-up was assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). Morbidity was compared using the χ2 test, Mann-Whitney U test, and Student t test. Survival was analyzed with Kaplan-Meier estimation. Results: Of 210 mitral surgery recipients, 67 (31.9%) underwent concomitant tricuspid surgery. The concomitant tricuspid surgery cohort had greater preoperative dialysis use (10.5% vs 3.5%; P = .043) but similar age, New York Heart Association class, and cardiac surgery history relative to the nonconcomitant cohort (P > .05 for all). The concomitant tricuspid surgery cohort had a longer cardiopulmonary bypass time (144 minutes vs 122 minutes; P = .005) but a similar rate of mitral repair (P = .220). Postoperative KCCQ-12 scores reflected high quality of life in both cohorts (95.1 vs 89.1; P = .167). The concomitant tricuspid surgery cohort trended toward a higher perioperative pacemaker placement rate (22.8% vs 12.7%; P = .088) but were less likely to develop severe TR (0.0% vs 13.0%; P = .004). Overall survival was comparable between the 2 cohorts at 1 year (84.9% vs 81.6%; P = .628) and 5 years (73.5% vs 57.9%; P = .078). Five-year survival free from severe TR was higher in the concomitant cohort (73.5% vs 54.3%; P = .032). Conclusions: Concomitant tricuspid surgery for moderate TR is associated with increased 5-year survival free from severe TR but not with increased quality of life.

Extended criteria donor organ use for heart-lung transplantation in the modern era

Abstract Background: Demand for donor hearts and lungs exceeds their supply. Extended Criteria Donor (ECD) organs are used to help meet this demand, but their impact on heart-lung transplantation outcomes is poorly characterized. Methods and results: The United Network for Organ Sharing was queried for data on adult heart-lung transplantation recipients (n = 447) from 2005‒2021. Recipients were stratified based on whether they received ECD hearts and/or lungs. Morbidity was analyzed using Kruskal-Wallis, chi-square, and Fisher's exact tests. Mortality was analyzed using Kaplan-Meier estimation, log-rank tests and Cox regression. Sixty-five (14.5%) patients received two ECD organs, 134 (30.0%) received only an ECD lung, and 65 (14.5%) only an ECD heart. Recipients of two ECD organs were older, more likely to have diabetes, and more likely transplanted from 2015‒2021 (p < 0.05). Groups did not differ by pre-transplant diagnosis, intensive care unit disposition, life support use, or hemodynam-ics. Group five-year survival rates ranged from 54.5% to 63.2% (p = 0.428). Groups did not differ by 30-day mortality, strokes, graft rejection, or hospital length of stay. Conclusions: Using ECD hearts and/or lungs for heart-lung transplantation is not associated with increased mortality and is a safe strategy for increasing donor organ supply in this complex patient population.

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

OBJECTIVES: The decision to perform simultaneous heart-kidney transplant (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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Antithrombotic therapy for durable left ventricular assist devices - current strategies and future directions.

Left ventricular assist devices (LVADs) improve survival and quality of life for patients with advanced heart failure but are associated with high rates of thromboembolic and hemorrhagic complications. Antithrombotic therapy is required following LVAD implantation, though practices vary. Identifying a therapeutic strategy that minimizes the risks of thromboembolic and hemorrhagic complications is critical to optimizing patient outcomes and is an area of active investigation. This paper reviews strategies for initiating and maintaining antithrombotic therapy in durable LVAD recipients, focusing on those with centrifugal-flow devices.

Interaction between donor obesity and prolonged donor ischemic time in heart transplantation.

BACKGROUND: The purpose of the study was to determine the impact of donor obesity on outcomes following heart transplantation in the setting of routine (<4 h) and prolonged (≥4 h) organ ischemic times. METHODS: Retrospective review of the 2000-2020 United Network for Organ Sharing Database was performed to identify adult heart transplant recipients and donors. Nearest-neighbor propensity score matching by donor obesity was performed separately among routine and prolonged cohorts, with Kaplan-Meier survival estimates used to assess survival at 5 years following transplantation. RESULTS: A total of 43,304 heart transplant recipients were included in analysis, with 15,925 (36.8 %) receiving obese donor hearts. After propensity-score matching, 30-day mortality and 5-year survival following transplantation were not statistically different between recipients of obese and non-obese donor hearts when organ ischemic times were routine. In the setting of prolonged organ ischemic times, those receiving obese donor hearts experienced lower 30-day mortality (5.1 % vs 6.7 %, p = 0.04) and improved 5-year survival (74.9 % vs 71.2 %, p < 0.01) compared to non-obese donor hearts. CONCLUSIONS: Recipients of obese donor hearts experienced improved outcomes compared to those receiving non-obese donor hearts when organ ischemic times exceeded 4 h. These findings suggest that the detrimental impact of prolonged organ ischemic time may be attenuated by donor obesity.

Failure to rescue: obesity increases the risk of mortality following early graft failure in heart transplantation in UNOS database patients.

OBJECTIVES: Early graft failure (EGF) is a devastating postoperative complication following heart transplant. Institutional studies have modelled donor and recipient risk factors predictive of graft failure. To date, no studies have assessed specific recipient profiles associated with mortality after recipients suffer from EGF. The objective of this study was to identify this recipient profile. METHODS: We performed a retrospective review of patients in the United Network for Organ Sharing database undergoing heart transplant from August 2000 to September 2019. EGF was defined as graft dysfunction at 24 hours post-heart transplant. The primary outcome was 90-day mortality. To isolate recipient characteristics associated with mortality, we performed the univariate analysis on 24 recipient characteristics adjusted for high-risk donor characteristics (ischaemic time, donor age, race mismatch, BUN/creatinine ratio) predictive of 1-year mortality (P < 0.2). We then performed backward stepwise multivariable regression adjusted for identified donor characteristics to determine recipient characteristics associated with mortality after EGF (P < 0.05). RESULTS: We identified 302 patients diagnosed with post-transplant EGF. Among these patients, mortality was 82% within 90 days of transplantation. Adjusted univariate analysis identified 7 factors associated with mortality. Adjusted backward stepwise multivariable regression identified BMI > 30 as predictive of mortality at 90 days after EGF. CONCLUSIONS: Patients who develop EGF after heart transplant are at high risk for mortality. Careful discussion regarding transplant candidacy and risk is warranted in obese patients. In addition, minimizing donor factors associated with graft dysfunction is critical during preoperative planning in these recipients.