Metabolic Choreography of Energy Substrates During DCD Heart Perfusion.

Background: The number of patients waiting for heart transplant far exceeds the number of hearts available. Donation after circulatory death (DCD) combined with machine perfusion can increase the number of transplantable hearts by as much as 48%. Emerging studies also suggest machine perfusion could enable allograft "reconditioning" to optimize outcomes. However, a detailed understanding of the energetic substrates and metabolic changes during perfusion is lacking. Methods: Metabolites were analyzed using 1-dimensional 1H and 2-dimensional 13C-1H heteronuclear spectrum quantum correlation nuclear magnetic resonance spectroscopy on serial perfusate samples (N = 98) from 32 DCD hearts that were successfully transplanted. Wilcoxon signed-rank and Kruskal-Wallis tests were used to test for significant differences in metabolite resonances during perfusion and network analysis was used to uncover altered metabolic pathways. Results: Metabolite differences were observed comparing baseline perfusate to samples from hearts at time points 1-2, 3-4, and 5-6 h of perfusion and all pairwise combinations. Among the most significant changes observed were a steady decrease in fatty acids and succinate and an increase in amino acids, especially alanine, glutamine, and glycine. This core set of metabolites was also altered in a DCD porcine model perfused with a nonblood-based perfusate. Conclusions: Temporal metabolic changes were identified during ex vivo perfusion of DCD hearts. Fatty acids, which are normally the predominant myocardial energy source, are rapidly depleted, while amino acids such as alanine, glutamine, and glycine increase. We also noted depletion of ketone, ß-hydroxybutyric acid, which is known to have cardioprotective properties. Collectively, these results suggest a shift in energy substrates and provide a basis to design optimal preservation techniques during perfusion.

Sex, Atrial Fibrillation, and Long-Term Mortality After Cardiac Surgery.

Importance: There are limited data on the association of sex with the incidence of postoperative atrial fibrillation (poAF) and subsequent long-term mortality after cardiac surgery. Objective: To evaluate whether the incidence of poAF and associated long-term mortality after cardiac surgery differ by sex. Design, Setting, and Participants: This retrospective cohort study was conducted at 2 tertiary care centers in Massachusetts from January 1, 2002, until October 1, 2016, with follow-up until December 1, 2022. Adult (aged >20 years) women and men undergoing coronary artery bypass graft surgery, aortic valve surgery, mitral valve surgery, and combined procedures with cardiopulmonary bypass were examined using medical records. Patients who had data on poAF were included in data analyses. Exposures: Sex and poAF. Main Outcomes and Measures: Primary outcomes were the incidence of poAF and all-cause mortality. poAF was defined as any atrial fibrillation detected on electrocardiogram (EKG) during the index hospitalization in patients presenting for surgery in normal sinus rhythm. Data on poAF were obtained from EKG reports and supplemented by information from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. All-cause mortality was assessed via hospital records. The hypotheses were formulated prior to data analysis. Results: Among 21 568 patients with poAF data (mean [SD] age, 66.5 [12.4] years), 2694 of 6601 women (40.8%) and 5805 of 14 967 men (38.8%) developed poAF. In a multivariable logistic regression model, women had lower risk of poAF (odds ratio [OR], 0.85; 95% CI, 0.79-0.91; P < .001). During the follow-up study period, 1294 women (50.4%) and 2376 men (48.9%) in the poAF group as well as 1273 women (49.6%) and 2484 men (51.1%) in the non-poAF group died. Cox proportional hazards analysis found that the association between poAF and mortality was significantly moderated (ie, effect modified) by sex. Compared with same-sex individuals without poAF, men with poAF had a 17% higher mortality hazard (hazard ratio [HR], 1.17; 95% CI, 1.11-1.25; P < .001), and women with poAF had a 31% higher mortality hazard (HR, 1.31; 95% CI, 1.21-1.42; P < .001). Conclusions and Relevance: In this retrospective cohort study of 21 568 patients who underwent cardiac surgery, women were less likely to develop poAF than men when controlling for other relevant characteristics; however, women who did develop poAF had a higher risk of long-term mortality than men who developed poAF. This observed elevated risk calls for a tailored approach to perioperative care in women undergoing cardiac surgery.

Hematocrit and Renal Failure in Aortic Arch Surgery: A Society of Thoracic Surgeons Database Study.

BACKGROUND: This study examined the association between cardiopulmonary bypass (CPB) hematocrit and postoperative acute renal failure (ARF) in patients undergoing aortic arch surgery with hypothermic circulatory arrest. METHODS: The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried from 2011 to 2019 for patients undergoing aortic arch surgery with hypothermic circulatory arrest. A multivariable logistic regression model estimated the adjusted odds of postoperative ARF on the basis of CPB hematocrit. Effects were stratified by preoperative kidney function and the duration of hypothermic circulatory arrest by using interaction terms. The study also investigated the association between postoperative ARF and major postoperative outcomes by using multivariable regression models. RESULTS: On adjusted analysis, higher CPB hematocrit (>20%-25%, >25%-30%, >30%) was associated with lower odds of ARF as compared with lower CPB hematocrit (≤20%) (>20-25%, aOR, 0.78; 95% CI, 0.65-0.93; P = .006; >25%-30%, aOR, 0.65; 95% CI, 0.50-0.84; P = .0007; >30%, aOR, 0.45; 95% CI, 0.28-0.72; P = .0008). The predicted probability of postoperative ARF by CPB hematocrit was higher in patients with lower preoperative renal function (estimated glomerular filtration rate, <60 mL/min/1.73 m2) (interaction P = .03). The association between hematocrit and postoperative ARF was not significantly modified by hypothermic circulatory arrest time (interaction P = .74). All postoperative outcomes were significantly worse in patients with postoperative ARF (all P < .0001). CONCLUSIONS: Among patients undergoing aortic arch surgery, a higher CPB hematocrit level is associated with reduced likelihood of postoperative ARF. Preoperative renal function, but not hypothermic circulatory arrest duration, significantly modified this association. The maintenance of higher CPB hematocrit may reduce the incidence of postoperative ARF, especially for patients with poor preoperative renal function.

Cardiac Loading using Passive Left Atrial Pressurization and Passive Afterload for Graft Assessment.

Ex vivo machine perfusion or normothermic machine perfusion is a preservation method that has gained great importance in the transplantation field. Despite the immense opportunity for assessment due to the beating state of the heart, current clinical practice depends on limited metabolic trends for graft evaluation. Hemodynamic measurements obtained from left ventricular loading have garnered significant attention within the field due to their potential as objective assessment parameters. In effect, this protocol provides an easy and effective manner of incorporating loading capabilities to established Langendorff perfusion systems through the simple addition of an extra reservoir. Furthermore, it demonstrates the feasibility of employing passive left atrial pressurization for loading, an approach that, to our knowledge, has not been previously demonstrated. This approach is complemented by a passive Windkessel base afterload, which acts as a compliance chamber to maximize myocardial perfusion during diastole. Lastly, it highlights the capability of capturing functional metrics during cardiac loading, including left ventricular pulse pressure, contractility, and relaxation, to uncover deficiencies in cardiac graft function after extended periods of preservation times (˃6 h).

Comparative effectiveness of antiplatelet therapies for saphenous venous graft occlusion and cardiovascular outcomes: a network meta-analysis.

INTRODUCTION: The ideal antiplatelet therapy to maintain graft patency after coronary artery bypass graft surgery (CABG) remains controversial. This review of randomized controlled trials (RCTs) aims to compare aspirin monotherapy, ticagrelor monotherapy, dual antiplatelet therapy (DAPT) with aspirin and ticagrelor (Asp+Tica) or with aspirin and clopidogrel (Asp+Clopi) to evaluate differences in post-CABG saphenous vein graft (SVG) occlusion, internal mammary artery (IMA) occlusion, myocardial infarction (MI), bleeding, and all-cause mortality (ACM) rates. EVIDENCE ACQUISITION: The literature review was conducted on several electronic databases, including Medline, Embase, and Cochrane Central, from inception to August 10, 2022. Data was extracted using a predefined proforma. A Bayesian random-effects model was used for calculating point effect estimates (odds ratio and standard deviation). Quality assessment was done using the Cochrane RoB-2 tool. EVIDENCE SYNTHESIS: Ten RCTs comprising 2139 patients taking anti-platelets post-CABG were included. For preventing SVG occlusion, Asp+Tica showed the lowest mean AR of 0.144±0.068. Asp+Tica also showed a trend toward lesser postoperative MI risk and lower ACM rates, with a mean AR of 0.040±0.053 and 0.018±0.029, respectively. For maintaining IMA graft patency, Asp+Clopi showed the lowest mean AR of 0.092±0.053. Ticagrelor had the lowest mean AR of 0.049±0.075, with Asp+Tica showing a similar mean AR of 0.049±0.045 for postoperative major bleeding risk. CONCLUSIONS: Our analysis demonstrates that Asp+Tica can be the ideal therapy for patients undergoing CABG using SVG as it decreases the risk of post-CABG SVG occlusion and is not associated with a significantly higher risk for major bleeding.

Modified Langendorff Perfusion Method for Extended Perfusion Times of Rodent Cardiac Grafts.

Despite important advancements in the diagnosis and treatment of cardiovascular diseases (CVDs), the field is in urgent need of increased research and scientific advancement. As a result, innovation, improvement and/or repurposing of the available research toolset can provide improved testbeds for research advancement. Langendorff perfusion is an extremely valuable research technique for the field of CVD research that can be modified to accommodate a wide array of experimental needs. This tailoring can be achieved by personalizing a large number of perfusion parameters, including perfusion pressure, flow, perfusate, temperature, etc. This protocol demonstrates the versatility of Langendorff perfusion and the feasibility of achieving longer perfusion times (4 h) without graft function loss by utilizing lower perfusion pressures (30-35 mmHg). Achieving extended perfusion times without graft damage and/or function loss caused by the technique itself has the potential to eliminate confounding elements from experimental results. In effect, in scientific circumstances where longer perfusion times are relevant to the experimental needs (i.e., drug treatments, immunological response analysis, gene editing, graft preservation, etc.), lower perfusion pressures can be key for scientific success.

The Public Health Service "Increased Risk" 2020 Policy Change Has not Improved Organ Utilization in the United States: A Nationwide Cohort Study.

Objective: To assess the effects of the 2020 United States Public Health Service (PHS) "Increased Risk" Guidelines update. Background: Donors labeled as "Increased Risk" for transmission of infectious diseases have been found to have decreased organ utilization rates despite no significant impact on recipient survival. Recently, the PHS provided an updated guideline focused on "Increased Risk" organ donors, which included the removal of the "Increased Risk" label and the elimination of the separate informed consent form, although the actual increased risk status of donors is still ultimately transmitted to transplant physicians. We sought to analyze the effect of this update on organ utilization rates. Methods: This was a retrospective analysis of the Organ Procurement and Transplantation Network database which compared donor organ utilization in the 2 years before the June 2020 PHS Guideline update for increased-risk donor organs (June 2018-May 2020) versus the 2 years after the update (August 2020-July 2022). The organ utilization rate for each donor was determined by dividing the number of organs transplanted by the total number of organs available for procurement. Student t test and multivariable logistic regression models were used for analysis. Results: There were 17,272 donors in the preupdate cohort and 17,922 donors in the postupdate cohort; of these, 4,977 (28.8%) and 3,893 (21.7%) donors were considered "Increased Risk", respectively. There was a 2% decrease in overall organ utilization rates after the update, driven by a 3% decrease in liver utilization rates and a 2% decrease in lung utilization rates. After multivariable adjustment, donors in the postupdate cohort had 10% decreased odds of having all organs transplanted. Conclusions: The 2020 PHS "Increased Risk" Donor Guideline update was not associated with an increase in organ utilization rates in the first 2 years after its implementation, despite a decrease in the proportion of donors considered to be at higher risk. Further efforts to educate the community on the safe usage of high-risk organs are needed and may increase organ utilization.

Tracheostomy is associated with decreased vasoactive-inotropic score in postoperative cardiac surgery patients on prolonged mechanical ventilation.

Objective: We sought to quantify the influence that tracheostomy placement has on the hemodynamic stability of postoperative cardiac surgery patients with persistent ventilatory requirements. Methods: A retrospective, single-center, and observational analysis of postoperative cardiac surgery patients with prolonged mechanical ventilation who underwent tracheostomy placement from 2018 to 2022 was conducted. Patients were excluded if receiving mechanical circulatory support or if they had an unrelated significant complication 3 days surrounding tracheostomy placement. Vasoactive and inotropic requirements were quantified using the Vasoactive-Inotrope Score. Results: Sixty-one patients were identified, of whom 58 met inclusion criteria. The median vasoactive-inotrope score over the 3 days before tracheostomy compared with 3 days after decreased from 3.35 days (interquartile range, 0-8.79) to 0 days (interquartile range, 0-7.79 days) (P = .027). Graphic representation of this trend demonstrates a clear inflection point at the time of tracheostomy. Also, after tracheostomy placement, fewer patients were on vasoactive/inotropic infusions (67.2% [n = 39] pre vs 24.1% [n = 14] post; P < .001) and sedative infusions (62.1% [n = 36] pre vs 27.6% [n = 16] post; P < .001). The percent of patients on active mechanical ventilation did not differ. Conclusions: The median vasoactive-inotrope score in cardiac surgery patients with prolonged mechanical ventilation was significantly reduced after tracheostomy placement. There was also a significant reduction in the number of patients on vasoactive/inotropic and sedative infusions 3 days after tracheostomy. These data suggest that tracheostomy has a positive effect on the hemodynamic stability of patients after cardiac surgery and should be considered to facilitate postoperative recovery.

Pulmonary Vein Stenosis After Single Lung Transplantation.

A 72-year-old man with interstitial lung disease underwent a planned single lung transplantation. His late postoperative course was notable for hemodynamic deterioration, after which severe right pulmonary vein anastomotic stenosis was identified via echocardiogram. The case highlights a rare complication of lung transplantation diagnosed by using transesophageal echocardiogram.

Vasoplegic syndrome during heart transplantation: A systematic review and meta-analysis.

BACKGROUND: Vasoplegic syndrome (VS) is a common occurrence during heart transplantation (HT). It currently lacks a uniform definition between transplant centers, and its pathophysiology and treatment remain enigmatic. This systematic review summarizes the available published clinical data regarding VS during HT. METHODS: We searched databases for all published reports on VS during HT. Data collected included the incidence of VS in the HT population, patient and intraoperative characteristics, and postoperative outcomes. RESULTS: Twenty-two publications were included in this review. The prevalence of VS during HT was 28.72% (95% confidence interval: 27.37%, 30.10%). Factors associated with VS included male sex, higher body mass index, hypothyroidism, pre-HT left ventricular assist device or venoarterial extracorporeal membrane oxygenation (VA-ECMO), pre-HT calcium channel blocker or amiodarone usage, longer cardiopulmonary bypass time, and higher blood product transfusion requirement. Patients who developed VS were more likely to require postoperative VA-ECMO support, renal replacement therapy, reoperation for bleeding, longer mechanical ventilation, and a greater 30-day and 1-year mortality. CONCLUSIONS: The results of our systematic review are an initial step for providing clinicians with data that can help identify high-risk patients and avenues for potential risk mitigation. Establishing guidelines that officially define VS will aid in the precise diagnosis of these patients during HT and guide treatment. Future studies of treatment strategies for refractory VS are needed in this high-risk patient population.

A Pilot Study Using Machine Learning Algorithms and Wearable Technology for the Early Detection of Postoperative Complications After Cardiothoracic Surgery.

OBJECTIVE: To evaluate whether a machine learning algorithm (i.e. the "NightSignal" algorithm) can be used for the detection of postoperative complications prior to symptom onset after cardiothoracic surgery. SUMMARY BACKGROUND DATA: Methods that enable the early detection of postoperative complications after cardiothoracic surgery are needed. METHODS: This was a prospective observational cohort study conducted from July 2021 to February 2023 at a single academic tertiary care hospital. Patients aged 18 years or older scheduled to undergo cardiothoracic surgery were recruited. Study participants wore a Fitbit watch continuously for at least 1 week preoperatively and up to 90-days postoperatively. The ability of the NightSignal algorithm-which was previously developed for the early detection of Covid-19-to detect postoperative complications was evaluated. The primary outcomes were algorithm sensitivity and specificity for postoperative event detection. RESULTS: A total of 56 patients undergoing cardiothoracic surgery met inclusion criteria, of which 24 (42.9%) underwent thoracic operations and 32 (57.1%) underwent cardiac operations. The median age was 62 (IQR: 51-68) years and 30 (53.6%) patients were female. The NightSignal algorithm detected 17 of the 21 postoperative events a median of 2 (IQR: 1-3) days prior to symptom onset, representing a sensitivity of 81%. The specificity, negative predictive value, and positive predictive value of the algorithm for the detection of postoperative events were 75%, 97%, and 28%, respectively. CONCLUSIONS: Machine learning analysis of biometric data collected from wearable devices has the potential to detect postoperative complications-prior to symptom onset-after cardiothoracic surgery.

Enhanced recovery protocols after surgery: A systematic review and meta-analysis of randomized trials in cardiac surgery.

BACKGROUND: Previous meta-analyses combining randomized and observational evidence in cardiac surgery have shown positive impact of enhanced recovery protocols after surgery (ERAS) on postoperative outcomes. However, definitive data based on randomized studies are missing, and the entirety of the ERAS measures and pathway, as recently systematized in guidelines and consensus statements, have not been captured in the published studies. The available literature actually focuses on "ERAS-like" protocols or only limited number of ERAS measures. This study aims at analyzing all randomized studies applying ERAS-like protocols in cardiac surgery for perioperative outcomes. METHODS: A meta-analysis of randomized controlled trials (RCTs) comparing ERAS-like with standard protocols of perioperative care was performed (PROSPERO registration CRD42021283765). PRISMA guidelines were used for abstracting and assessing data. RESULTS: Thirteen single center RCTs (N = 1704, 850 in ERAS-like protocol and 854 in the standard care group) were selected. The most common procedures were surgical revascularization (66.3%) and valvular surgery (24.9%). No difference was found in the incidence of inhospital mortality between the ERAS and standard treatment group (risk ratio [RR] 0.61 [0.31; 1.20], p = 0.15). ERAS was associated with reduced intensive care unit (standardized mean difference [SMD] -0.57, p < 0.01) and hospital stay (SMD -0.23, p < 0.01) and reduced rates of overall complications when compared to the standard protocol (RR 0.60, p < 0.01) driven by the reduction in stroke (RR 0.29 [0.13; 0.62], p < 0.01). A significant heterogeneity in terms of the elements of the ERAS protocol included in the studies was observed. CONCLUSIONS: ERAS-like protocols have no impact on short-term survival after cardiac surgery but allows for a faster hospital discharge while potentially reducing surgical complications. However, this study highlights a significant nonadherence and heterogeneity to the entirety of ERAS protocols warranting further RCTs in this field including a greater number of elements of the framework.

One Year Outcomes Following Transplantation with COVID-19-Positive Donor Hearts: A National Database Cohort Study.

The current understanding of the safety of heart transplantation from COVID-19+ donors is uncertain. Preliminary studies suggest that heart transplants from these donors may be feasible. We analyzed 1-year outcomes in COVID-19+ donor heart recipients using 1:3 propensity matching. The OPTN database was queried for adult heart transplant recipients between 1 January 2020 and 30 September 2022. COVID-19+ donors were defined as those who tested positive on NATs or antigen tests within 21 days prior to procurement. Multiorgan transplants, retransplants, donors without COVID-19 testing, and recipients allocated under the old heart allocation system were excluded. A total of 7211 heart transplant recipients met the inclusion criteria, including 316 COVID-19+ donor heart recipients. Further, 290 COVID-19+ donor heart recipients were matched to 870 COVID-19- donor heart recipients. Survival was similar between the groups at 30 days (p = 0.46), 6 months (p = 0.17), and 1 year (p = 0.07). Recipients from COVID-19+ donors in the matched cohort were less likely to experience postoperative acute rejection prior to discharge (p = 0.01). National COVID-19+ donor heart usage varied by region: region 11 transplanted the most COVID-19+ hearts (15.8%), and region 6 transplanted the fewest (3.2%). Our findings indicate that COVID-19+ heart transplantation can be performed with safe early outcomes. Further analyses are needed to determine if long-term outcomes are equivalent between groups.

Acute rejection in donation after circulatory death (DCD) heart transplants.

BACKGROUND: Donation after circulatory death (DCD) heart transplantation has promising early survival, but the effects on rejection remain unclear. METHODS: The United Network for Organ Sharing database was queried for adult heart transplants from December 1, 2019, to December 31, 2021. Multiorgan transplants and loss to follow-up were excluded. The primary outcome was acute rejection, comparing DCD and donation after brain death (DBD) transplants. RESULTS: A total of 292 DCD and 5,582 DBD transplants met study criteria. Most DCD transplants were transplanted at status 3-4 (61.0%) compared to 58.6% of DBD recipients at status 1-2. DCD recipients were less likely to be hospitalized at transplant (26.7% vs 58.3%, p < 0.001) and to require intra-aortic balloon pumping (IABP; 9.6% vs 28.9%, p < 0.001), extracorporeal membrane oxygenation (ECMO; 0.3% vs 5.9%, p < 0.001) or temporary left ventricular assist device (LVAD; 1.0% vs 2.7%, p < 0.001). DCD recipients were more likely to have acute rejection prior to discharge (23.3% vs 18.4%, p = 0.044) and to be hospitalized for rejection (23.4% vs 11.4%, p = 0.003) at a median follow-up of 15 months; the latter remained significant after propensity matching. On multivariable logistic regression, DCD donation was an independent predictor of acute rejection (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.00-2.15, p = 0.048) and hospitalization for rejection (OR 2.03, 95% CI 1.06-3.70, p = 0.026). On center-specific subgroup analysis, DCD recipients continued to have higher rates of hospitalization for rejection (23.4% vs 13.8%, p = 0.043). CONCLUSIONS: DCD recipients are more likely to experience acute rejection. Early survival is similar between DCD and DBD recipients, but long-term implications of increased early rejection in DCD recipients require further investigation.

Textbook outcome: A novel metric in heart transplantation outcomes.

OBJECTIVE: Assessing heart transplant program quality using short-term survival is insufficient. We define and validate the composite metric textbook outcome and examine its association with overall survival. METHODS: We identified all primary, isolated adult heart transplants in the United Network for Organ Sharing/Organ Procurement and Transplantation Network Standard Transplant Analysis and Research files from May 1, 2005, to December 31, 2017. Textbook outcome was defined as length of stay 30 days or less; ejection fraction greater than 50% during 1-year follow-up; functional status 80% to 100% at 1 year; freedom from acute rejection, dialysis, and stroke during the index hospitalization; and freedom from graft failure, dialysis, rejection, retransplantation, and mortality during the first year post-transplant. Univariate and multivariate analyses were performed. Factors independently associated with textbook outcome were used to create a predictive nomogram. Conditional survival at 1 year was measured. RESULTS: A total of 24,620 patients were identified with 11,169 (45.4%, 95% confidence interval, 44.7-46.0) experiencing textbook outcome. Patients with textbook outcome were more likely free from preoperative mechanical support (odds ratio, 3.504, 95% confidence interval, 2.766 to 4.439, P < .001), free from preoperative dialysis (odds ratio, 2.295, 95% confidence interval, 1.868-2.819, P < .001), to be not hospitalized (odds ratio, 1.264, 95% confidence interval, 1.183-1.349, P < .001), to be nondiabetic (odds ratio, 1.187, 95% confidence interval, 1.113-1.266, P < .001), and to be nonsmokers (odds ratio, 1.160, 95% confidence interval,1.097-1.228, P < .001). Patients with textbook outcome have improved long-term survival relative to patients without textbook outcome who survive at least 1 year (hazard ratio for death, 0.547, 95% confidence interval, 0.504-0.593, P < .001). CONCLUSIONS: Textbook outcome is an alternative means of examining heart transplant outcomes and is associated with long-term survival. The use of textbook outcome as an adjunctive metric provides a holistic view of patient and center outcomes.

Does Failure to Rescue Drive Race/Ethnicity-based Disparities in Survival After Heart Transplantation?

OBJECTIVE: The objective was to assess whether race/ethnicity is an independent predictor of failure to rescue (FTR) after orthotopic heart transplantation (OHT). SUMMARY BACKGROUND DATA: Outcomes following OHT vary by patient level factors; for example, non-White patients have worse outcomes than White patients after OHT. Failure to rescue is an important factor associated with cardiac surgery outcomes, but its relationship to demographic factors is unknown. METHODS: Using the United Network for Organ Sharing database, we included all adult patients who underwent primary isolated OHT between 1/1/2006 snd 6/30/2021. FTR was defined as the inability to prevent mortality after at least one of the UNOS-designated postoperative complications. Donor, recipient, and transplant characteristics, including complications and FTR, were compared across race/ethnicity. Logistic regression models were created to identify factors associated with complications and FTR. Kaplan Meier and adjusted Cox proportional hazards models evaluated the association between race/ethnicity and posttransplant survival. RESULTS: There were 33,244 adult, isolated heart transplant recipients included: the distribution of race/ethnicity was 66% (n=21,937) White, 21.2% (7,062) Black, 8.3% (2,768) Hispanic, and 3.3% (1,096) Asian. The frequency of complications and FTR differed significantly by race/ethnicity. After adjustment, Hispanic recipients were more likely to experience FTR than White recipients (OR 1.327, 95% CI[1.075-1.639], P =0.02). Black recipients had lower 5-year survival compared with other races/ethnicities (HR 1.276, 95% CI[1.207-1.348], P <0.0001). CONCLUSIONS: In the US, Black recipients have an increased risk of mortality after OHT compared with White recipients, without associated differences in FTR. In contrast, Hispanic recipients have an increased likelihood of FTR, but no significant mortality difference compared with White recipients. These findings highlight the need for tailored approaches to addressing race/ethnicity-based health inequities in the practice of heart transplantation.