Predicted Heart Mass Research Articles

The Korean Organ Transplant Registry (KOTRY): Third Official Adult Heart Transplant Report.

The Korean Organ Transplant Registry (KOTRY) provided data for this third official report on adult heart transplantation (HT), including information from 709 recipients. Data from HTs performed at seven major centers in Korea between March 2014 and December 2020 were analyzed, focusing on immunosuppression, acute rejection, cardiac allograft vasculopathy (CAV), post-transplant survival, and mechanical circulatory support (MCS) usage. The median ages of the recipients and donors were 56.0 and 43.0 years, respectively. Cardiomyopathy and ischemic heart disease were the most common preceding conditions for HT. A significant portion of patients underwent HT at waiting list status 1 and 0. In the multivariate analysis, a predicted heart mass mismatch was associated with a higher risk of 1-year mortality. Patients over 70 years old had a significantly increased risk of 6-year mortality. The risk of CAV was higher for male donors and donors older than 45 years. Acute rejection was more likely in patients with panel reactive antibody levels above 80%, while statin use was associated with a reduced risk. The employment of left ventricular assist device as a bridge to transplantation increased from 2.17% to 22.4%. Pre-transplant extra-corporeal membrane oxygenation was associated with worse post-transplant survival. In this third KOTRY report, we analyzed changes in the characteristics of adult HT recipients and donors and their impact on post-transplant outcomes. The most notable discovery was the increased use of MCS before HT and their impact on post-transplant outcomes.

Application of donor predicted heart mass in heart transplant recipients with left ventricular assist device

IntroductionAn association between predicted heart mass (PHM) and post heart transplantation outcomes has been well established; however, there is limited data on the effect of donor PHM on recipients bridged with a durable left ventricular assist device (LVAD). This retrospective observational study seeks to challenge the theoretical benefit of oversizing donor hearts for recipients bridged with LVADs. MethodsAnalysis of the United Network for Organ Sharing (UNOS) database revealed 10,806 adult patients with one of three durable LVADs (HeartMate 2, HeartMate 3 [HM3], HeartWare [HVAD]) between January 1, 2015 and December 31, 2021. Baseline characteristics were compared between seven equally sized groups based on donor-to-recipient PHM. Univariable and multivariable Cox regression analyses were constructed to evaluate the effect of PHM size-matching on the primary outcome of 1-year post-transplant survival. Further analyses were performed specifically on HM3 patients and with PHM as a continuous variable. ResultsMultivariable analysis revealed that severely undersized donor hearts (PHM ratio < 0.86) resulted in worse outcomes with respect to 1-year mortality (HR 1.30; CI 1.03-1.64, p=0.03). There was no significant benefit to oversizing donor hearts. Similar results were found in patients bridged to transplant with HM3. ConclusionSimilar to prior studies on heart transplant recipients, recipients bridged with durable LVAD had worse outcomes when using severely undersized donor hearts. Oversized donor hearts did not significantly improve 1-year mortality, compared to size-matched references. These results were consistent in a subgroup analysis of patients bridged only with HM3 LVADs.

Impact of prolonged cardiopulmonary resuscitation on outcomes in heart transplantation with higher risk donor heart.

To evaluate the influence of prolonged cardiopulmonary resuscitation (CPR) on outcomes in heart transplantation with higher risk donor hearts (HRDHs). Patients transplanted in our hospital between May 2006 and December 2019 were divided into 2 groups, HRDH recipients and non HRDH recipients. HRDH was defined as meeting at least one of the following criteria: (1) donor left ventricular ejection fraction ≤ 50%, (2) donor-recipient predicted heart mass ratio < 0.8 or > 1.2, (3) donor age ≥ 55years, (4) ischemic time > 4h and (5) catecholamine index > 20. Recipients of HRDHs were divided into 3 groups according to the time of CPR (Group1: non-CPR, Group 2: less than 30min-CPR, and Group 3: longer than 30min CPR). A total of 125 recipients were enrolled in this study, composing of HRDH recipients (n = 97, 78%) and non HRDH recipients (n = 28, 22%). Overall survival and the rate of freedom from cardiac events at 10years after heart transplantation were comparable between two groups. Of 97 HRDH recipients, 54 (56%) without CPR, 22 (23%) with CPR < 30min, and 21 (22%) with CPR ≥ 30min were identified. One-year survival rates were not significantly different among three groups. The 1-year rate of freedom from cardiac events was not also statistically different, excluding the patients with coronary artery disease found in early postoperative period, which was thought to be donor-transmitted disease. Multivariate logistics regression for cardiac events identified that the CPR duration was not a risk factor even in HRDH-recipients. The CPR duration did not affect the outcomes after heart transplantation in HRDH recipients.

Metabolomic profiling during ex situ normothermic perfusion before heart transplantation defines patterns of substrate utilization and correlates with markers of allograft injury

PURPOSECardiac metabolism is altered in heart failure and ischemia-reperfusion injury states. We hypothesized that metabolomic profiling during ex-situ normothermic perfusion before heart transplantation (HT) would lend insight into myocardial substrate utilization and report on subclinical and clinical allograft dysfunction risk. METHODSMetabolomic profiling was performed on serial samples of ex-situ normothermic perfusate assaying biomarkers of myocardial injury in lactate and cardiac troponin I (TnI) as well as metabolites (66 acylcarnitines, 15 amino acids, non-esterified fatty acids (NEFA), ketones, and 3-hydroxybutyrate). We tested for change over time in injury biomarkers and metabolites, along with differential changes by recovery strategy (donation after circulatory death (DCD) v. donation after brain death (DBD)). We examined associations between metabolites, injury biomarkers, and primary graft dysfunction (PGD). Analyses were performed using linear mixed models adjusted for recovery strategy, assay batch, donor predicted heart mass, and time. RESULTSA total of 176 samples from 92 ex-situ perfusion runs were taken from donors with a mean age of 35 years (SD 11.3) years and a median total ex-situ perfusion time of 234 (IQR 84) minutes. Lactate trends over time differed significantly by recovery strategy, while TnI increased during ex-situ perfusion regardless of DCD v. DBD status. We found fuel substrates were rapidly depleted during ex-situ perfusion, most notably the branched-chain amino acids leucine/isoleucine, as well as ketones, 3-hydroxybutyrate, and NEFA (least squares (LS) mean difference from the first to last timepoint -1.7 - -4.5, FDR q<0.001). Several long-chain acylcarnitines (LCAC), including C16, C18, C18:1, C18:2, C18:3, C20:3, and C20:4 increased during the perfusion run (LS mean difference 0.42 – 0.67, q<0.001). Many LCACs were strongly associated with lactate and TnI. The change over time of many LCACs was significantly different for DCD vs. DBD, suggesting differential trends in fuel substrate utilization by ischemic injury pattern. Changes in leucine/isoleucine, arginine, C12:1-OH/C10:1-DC, and C16-OH/C14-DC were associated with increased odds of moderate-severe PGD. Neither end-of-run nor change in lactate or TnI was associated with PGD. CONCLUSIONMetabolomic profiling of ex-situ normothermic perfusion solution reveals a pattern of fuel substrate utilization that correlates with subclinical and clinical allograft dysfunction. This study highlights a potential role for interventions focused on fuel substrate modification in allograft conditioning during ex-situ perfusion to improve allograft outcomes.

Predicted heart mass based on ideal body weight for donor-to-recipient size matching.

Predicted heart mass (PHM) is a commonly used tool for donor-to-recipient size matching. However, incorporating body weight as part of PHM can be considered problematic given its high variability, and low metabolic nature of fat. We sought to assess whether substituting the actual donor and recipient weight with the ideal body weight (IBW) would affect the association of donor-to-recipient PHM ratio with 1-year and overall survival after heart transplantation. The United Network for Organ Sharing (UNOS) database was queried for adult patients who received a primary heart transplant between January 2000 and September 2021. Both PHM and ideal PHM (IPHM) ratios were associated with one-year (PHM: p=.003; IPHM: p=.0007) and overall (PHM: p = .02; IPHM: p=.02) survival. In the continuous analysis with restricted cubic splines, both PHM (p=.0003) and IPHM (p=.00001) were associated with relative hazards of death. IPHM is significantly associated with post-transplant survival and may be a useful compliment to PHM.

Donor/recipient ascending aortic diameter ratio as a novel potential metric for donor selection and improved clinical outcomes in heart transplantation: a propensity score-matched study.

Donor/recipient size matching is paramount in heart transplantation. Body weight, height, body mass index, body surface area, and predicted heart mass (PHM) ratios are generally used in size matching. Precise size matching is important to achieve better clinical outcomes. This study aims to determine the donor/recipient ascending aortic diameter (AAoD) ratio as a metric for donor selection and its effect on postoperative clinical outcomes in heart transplant patients. We retrospectively reviewed all consecutive patients who underwent heart transplantation from January 2015 to December 2018. A cutoff value of 0.8032 for the donor/recipient AAoD ratio (independent variable for the primary endpoint during unmatched cohort analysis) was determined for predicting in-hospital mortality. The patients were divided into two groups based on the cutoff value. Group A, AAoD < 0.8032 (n = 96), and Group B, AAoD > 0.8032 (n = 265). A propensity score-matched (PSM) study was performed to equalize the two groups comprising 77 patients each in terms of risk. A Cox regression model was developed to identify the independent preoperative variables affecting the primary end-point. The primary endpoint was all-cause in-hospital mortality. A total of 361 patients underwent heart transplantation during the given period. On the multivariate analysis, donor/recipient PHM ratio [HR 16.907, 95% confidence interval (CI) 1.535-186.246, P = 0.021], donor/recipient AAoD ratio < 0.8032 (HR 5.398, 95% CI 1.181-24.681, P = 0.030), and diabetes (HR 3.138, 95% CI 1.017-9.689, P = 0.047) were found to be independent predictors of in-hospital mortality. Group A had higher 3-year mortality than Group B (P = 0.022). The surgery time was longer and postoperative RBC, plasma, and platelets transfusion were higher in Group A (P < 0.05). Although not statistically significant the use of continuous renal replacement therapy (P = 0.054), and extracorporeal membrane oxygenation (P = 0.086), was realatively higher, and ventilation time (P = 0.079) was relatively longer in Group A. The donor/recipient AAoD ratio is a potential metric for patient matching and postoperative outcomes in heart transplantation. A donor/recipient AAoD ratio > 0.8032 could improve post-heart transplantation outcomes and donor heart utilization.

No Evidence for Oversizing Hearts and Donor Size Impact on 1-Year Survival in Heart Failure Patients With Left Ventricular Assist Device

The predicted heart mass (PHM) ratio has recently emerged as a better metric for donor-to-recipient size-matching than weight ratios. It is unknown whether this applies to transplant candidates on left ventricular assist device (LVAD) support. Our study examines if PHM ratio is optimal for size-matching specifically in the LVAD patient population. Patients with LVAD who received a heart transplant from January 1997 to December 2020 in the Scientific Registry of Transplant Recipients database were studied. We compared 5 size-matching metrics, including donor-recipient ratios of weight, height, body mass index, body surface area, and PHM. Single and multivariable Cox proportional hazards models for 1-year mortality were calculated. Our sample consisted of 11,891 patients. In our multivariate analysis, we found that patients in the undersized group with PHM ratios <0.83 had a hazard ratio for 1-year mortality of 1.34 (95% confidence interval 1.08 to 1.65, p=0.007) suggestive of increased mortality with the use of undersized donors. There was no statistical difference in mortality between the matched (PHM ratio 0.83 to 1.2) and oversized group (PHM ratio ≥1.2). In heart transplant recipients on LVAD support, the PHM ratio provides better risk stratification than other metrics. Use of undersized donor hearts with PHM ratio <0.83 confers higher 1-year mortality. Using oversized donor hearts for transplantation in recipients on LVAD support has no benefit.

Adequacy of Size Matching With Predicted Heart Mass Ratio in Diverse Types of Cardiomyopathies

Predicted heart mass ratio (PHMr) has been proposed as an optimal size metric in the selection of a donor heart for transplant; however, it is not known if the same size matching criteria pertains uniformly to all types of cardiomyopathies. Heart transplant recipients in the United Network for Organ Sharing registry database were categorized into 6 groups based on the type of cardiomyopathy, dilated, coronary artery disease, hypertrophic, restrictive, valvular and adult congenital heart disease. Patients in each group of etiology were stratified based on the PHMr into 5 groups: severely undersized <0.86, moderately undersized 0.86 to 0.94, matched 0.95 to 1.04, moderately oversized 1.05 to 1.24, and severely oversized >1.25. The survival and cause of death of patients in each etiology group were reviewed. The United Network for Organ Sharing registry database from January 1987 to July 2021 included 53,573 patients who received a heart transplant. Compared with patients with size matched hearts, recipients with dilated (hazard ratio 1.17, p=0.001) and valvular (hazard ratio 1.79, p=0.032) cardiomyopathy who had an undersized heart with PHMr <0.86 had decreased survival. In addition, the survival of patients with hypertrophic or restrictive cardiomyopathy and adult congenital heart disease was not affected by size matching based on the PHMr (0.601 and 0.079, respectively, p=0.873). In conclusion, our analysis suggests that the size matching criteria based on PHMr may not be uniform to all patients across various etiologies of cardiomyopathy. Therefore, the data can be used to increase the acceptance rate of donor hearts, particularly, for patients with hypertrophic, restrictive cardiomyopathy and congenital heart disease in which size matching is less significant for survival outcome.

Assessing Donor-Recipient Size Mismatch in Pediatric Heart Transplantation: Lessons Learned From Over 7,500 Transplants

BackgroundTo date, no studies have identified an optimal metric to match donor-recipient (D-R) pairs in pediatric heart transplantation (HT). ObjectivesThis study sought to identify size mismatch metrics that predicted graft survival post-HT. MethodsD-R pairs undergoing HT in Pediatric Heart Transplant Society database from 1993 to 2021 were included. Effects of size mismatch by height, weight, body mass index, body surface area, predicted heart mass, and total cardiac volume (TCV) on 1- and 5-year graft survival and morbidity outcomes (rejection and cardiac allograft vasculopathy) were evaluated. Cox models with stepwise selection identified size metrics that independently predicted graft survival. ResultsOf 7,715 D-R pairs, 36.0% were well matched (D-R ratio: −20% to +20%) by weight, 39.0% by predicted heart mass, 50.0% by body surface area, 57.0% by body mass index, 71.0% by height, and 93.0% by TCV. Of all size metrics, only D-R mismatch by height and TCV predicted graft survival at 1 and 5 years. Effects of D-R size mismatch on graft survival were nonlinear. At both 1 and 5 years post-HT, D-R undersizing and oversizing by height led to increased graft loss, with graft loss observed more frequently with undersizing. Moderately undersized donors by height (D-R ratio: <−30%) frequently experienced rejection post-HT (P < 0.001). Assessing D-R size matching by TCV, minimal donor undersizing was protective, while oversizing up to 25% was not associated with increased graft loss. ConclusionsIn pediatric HT, D-R appear most optimally matched using TCV. Only D-R size mismatch by TCV and height independently predicts graft survival. Standardizing size matching across centers may reduce donor discard.

Predicted Heart Mass: A Tale of 2 Ventricles.

Total predicted heart mass (PHM) is the recommended metric to assess donor-recipient size matching in patients undergoing heart transplantation. Separately measuring right ventricular (RV) and left ventricular (LV) PHM may improve risk prediction of 1-year graft failure. Adult heart transplant recipients from the UNOS database from 2000 to 2018 were included in the study. LV and RV PHM were modeled as restricted cubic splines. The association with 1-year graft failure was determined using adjusted Cox regression. The risk reclassification of using both LV and RV PHM versus total PHM was assessed using the net reclassification index. A total of 34 976 recipients were included. We observed a U-shaped association between total PHM and 1-year graft failure, such that risk increased for hearts undersized by >15% and those oversized by more than 27%. Graft failure incrementally increased when LV PHM was undersized by more than 5% and when RV was oversized by >20%. There was 1.5-fold greater risk of graft failure for an LV undersized by >26% or an RV oversized by more than 40%. Using LV and RV PHM risk-assessment separately led to a net reclassification index=8.5% ([95% CI, 5.3%-11.7%], nonevent net reclassification index=9.1%, event net reclassification index=-0.6%). The association between donor-recipient PHM match and the risk of graft failure after heart transplantation can be further understood as risk attributable to LV undersizing and RV oversizing. Assessing LV and RV PHM separately instead of total PHM could further refine the methods used to match donors and recipients for heart transplantation, minimize the risk of 1-year graft failure, and increase the use of donor organs.

Association of Size Matching Using Predicted Heart Mass With Mortality in Heart Transplant Recipients With Obesity or High Pulmonary Vascular Resistance

Pretransplant obesity and higher pulmonary vascular resistance (PVR) are risk factors for death after heart transplant. However, it remains unclear whether appropriate donor-to-recipient size matching using predicted heart mass (PHM) is associated with lower risk. To investigate the association of size matching using PHM with risk of death posttransplant among patients with obesity and/or higher PVR. All adult patients (>18 years) who underwent heart transplant between 2003 and 2022 with available information using the United Network for Organ Sharing cohort database. Multivariable Cox models and multivariable-adjusted spline curves were used to examine the risk of death posttransplant with PHM matching. Data were analyzed from October 2022 to March 2023. Recipient's body mass index (BMI) in categories (<18.0 [underweight], 18.1-24.9 [normal weight, reference], 25.0-29.9 [overweight], 30.0-34.9 [obese 1], 35-39.9 [obese 2], and ≥40.0 [obese 3]) and recipient's pretransplant PVR in categories of less than 4 (29 061 participants), 4 to 6 (2842 participants), and more than 6 Wood units (968 participants); and less than 3 (24 950 participants), 3 to 5 (6115 participants), and 5 or more (1806 participants) Wood units. All-cause death posttransplant on follow-up. The mean (SD) age of the cohort of 37 712 was 52.8 (12.8) years, 27 976 (74%) were male, 25 342 were non-Hispanic White (68.0%), 7664 were Black (20.4%), and 3139 were Hispanic or Latino (8.5%). A total of 12 413 recipients (32.9%) had a normal BMI, 13 849 (36.7%) had overweight, and 10 814 (28.7%) had obesity. On follow-up (median [IQR] 5.05 [0-19.4] years), 12 785 recipients (3046 female) died. For patients with normal weight, overweight, or obese 2, receiving a PHM-undermatched heart was associated with an increased risk of death (normal weight hazard ratio [HR], 1.20; 95% CI, 1.07-1.34; overweight HR, 1.12; 95% CI, 1.02-1.23; and obese 2 HR, 1.07; 95% CI, 1.01-1.14). Moreover, patients with higher pretransplant PVR who received an undermatched heart had a higher risk of death posttransplant in multivariable-adjusted spline curves in graded fashion until appropriately matched. In contrast, risk of death among patients receiving a PHM-overmatched heart did not differ from the appropriately matched group, including in recipients with an elevated pretransplant PVR. In this cohort study, undermatching donor-to-recipient size according to PHM was associated with higher posttransplant mortality, specifically in patients with normal weight, overweight, or class II obesity and in patients with elevated pretransplant PVR. Overmatching donor-to-recipient size was not associated with posttransplant survival.

Indexed donor cardiac output for improved size matching in heart transplantation: A United Network for Organ Sharing database analysis

ObjectiveImplantation of an appropriately sized donor heart is critical for optimal outcomes after heart transplantation. Although predicted heart mass has recently gained consideration, there remains a need for improved granularity in size matching, particularly among small donor hearts. We sought to determine if indexed donor cardiac output is a sensitive metric to assess the adequacy of a donor heart for a given recipient. MethodsA retrospective analysis was performed (2003-2021) in isolated orthotopic heart transplant recipients from the United Network for Organ Sharing database. Donor cardiac output was divided by recipient body surface area to compute cardiac index (donor cardiac index). Predicted heart mass ratio was computed as donor/recipient predicted heart mass. The primary outcome was mortality 1 year after transplant. ResultsAmong transplant recipients, median donor cardiac output was 7.3 (5.8-9.0) liters per minute and donor cardiac index was 3.7 (3.0-4.6) liters per minute/m2. Predicted heart mass ratio was 1.01 (0.91-1.13). After multivariable adjustment, higher donor cardiac index was associated with lower 1-year mortality risk (odds ratio, 0.92, P = .042). Recipients with predicted heart mass ratio less than 0.80 (n = 255) had a lower median donor cardiac index than those with a predicted heart mass ratio of 0.80 or greater (3.2 vs 3.7, P < .001). As predicted, heart mass ratio became smaller and the association between donor cardiac index and 1-year mortality became progressively stronger. ConclusionsHigher donor cardiac index was associated with a lower probability of 1-year mortality among patients undergoing heart transplantation and served to further quantify mortality risk among those with a small predicted heart mass ratio. Donor cardiac index appears to be an effective tool for size matching and may serve as an adjunctive strategy among small donor hearts with a low predicted heart mass ratio.

(520) Limitations of Cardiac Size Matching Based on Predicted Heart Mass in the 2018 Heart Allocation System

(520) Limitations of Cardiac Size Matching Based on Predicted Heart Mass in the 2018 Heart Allocation System

How Do Left Ventricular Assist Device Subtypes Compare When Size Matched By Predicted Heart Mass Ratio

How Do Left Ventricular Assist Device Subtypes Compare When Size Matched By Predicted Heart Mass Ratio

(535) Evaluating Mismatch in Adult Heart Transplantation: Risk Factors for Patients with and without Relevant Predicted Heart Mass Ratio Mismatch

(535) Evaluating Mismatch in Adult Heart Transplantation: Risk Factors for Patients with and without Relevant Predicted Heart Mass Ratio Mismatch

Choosing wisely: incorporating appropriate donor-recipient size matching in heart transplantation.

Historically, transplantation of a female donor heart to male recipient has been viewed with caution given evidence of suboptimal outcomes, particularly in special populations such as patients with pulmonary hypertension or those supported by ventricular assist devices. However, the use of predicted heart mass ratio for donor-recipient size matching demonstrated that the size of the organ rather than sex of the donor was most responsible for the outcomes. With the advent of the predicted heart mass ratio, avoiding female donor hearts for male recipients is no longer justified and may result in unnecessary waste of available organs. In this review, we highlight the value of donor-recipient sizing by predicted heart mass ratio and summarize the evidence of different approaches to the donor-to-recipient size and sex matching. We conclude that the utilization of predicted heart mass is currently considered a preferred method of matching heart donors and recipients.

Donor hyperoxia is a novel risk factor for severe cardiac primary graft dysfunction

Primary graft dysfunction (PGD) is a major cause of early mortality following heart transplant (HT). Donor risk factors for the development of PGD are incompletely characterized. Donor management goals (DMG) are predefined critical care endpoints used to optimize donors. We evaluated the relationship between DMGs as well as non-DMG parameters, and the development of PGD after HT. A cohort of HT recipients from 2 transplant centers between 1/1/12 and 12/31/19 was linked to their respective donors in the United Network for Organ Sharing (UNOS) DMG Registry (n=1,079). PGD was defined according to modified ISHLT criteria. Variables were subject to univariate and multivariable multinomial modeling with development of mild/moderate or severe PGD as the outcome variable. A second multicenter cohort of 4,010 donors from the DMG Registry was used for validation. Mild/moderate and severe PGD occurred in 15% and 6% of the cohort. Multivariable modeling revealed 6 variables independently associated with mild/moderate and 6 associated with severe PGD, respectively. Recipient use of amiodarone plus beta-blocker, recipient mechanical circulatory support, donor age, donor fraction of inspired oxygen (FiO2), and donor creatinine increased risk whereas predicted heart mass ratio decreased risk of severe PGD. We found that donor age and FiO2 ≥ 40% were associated with an increased risk of death within 90 days post-transplant in a multicenter cohort. Donor hyperoxia at heart recovery is a novel risk factor for severe primary graft dysfunction and early recipient death. These results suggest that excessive oxygen supplementation should be minimized during donor management.

Modern outcomes of heart-lung transplantation: assessing the impact of the updated US allocation system.

In 2018, the United Network for Organ Sharing modified their heart allocation policy to reduce waitlist mortality and prioritize patients with the greatest acuity. Considering declining rates of combined heart-lung transplantation, this study sought to investigate the impact of the new allocation system on waitlist and post-transplant outcomes of patients listed for combined heart-lung transplantation. Adult patients listed for combined heart-lung transplant between 2012 and 2021 were included. Patients were stratified according to listing era. Competing risk regression was used to assess waitlist outcomes. Cox proportional hazards regression was used to establish risk factors for post-transplant mortality. A total of 511 patients were included, of whom 295 (57.8%) were listed in era 1 and 216 (42.2%) in era 2. Era 2 was associated with increased likelihood of transplant (adjusted standard hazard ratio (aSHR): 1.60 [1.23-2.07]; P < 0.01) and decreased waitlist mortality (aSHR: 0.43 [0.25-0.73]; P < 0.01). Despite longer ischaemic times and increased use of preoperative veno-arterial extracorporeal membrane oxygenation (ECMO) in era 2, early post-transplant survival was equivalent. Predicted heart mass ratio <0.8 (Hazard ratio (HR); 3.24; P = 0.01), ventilator support (HR: 3.83; P < 0.01) and greater ischaemic times (HR: 1.80; P < 0.01) independently predicted the mortality. Procedures at high centre volumes (HR: 0.36; P = 0.04) were associated with decreased mortality. Use of ECMO was not predictive of mortality in the modern era. The allocation policy change has led to improvements in waitlist outcomes in patients listed for heart-lung transplantation. Despite increased ischaemic times and use of ECMO, early post-transplant survival was equivalent.

Impact of predicted heart mass-based size matching on survival after heart transplantation in Korea: Analysis of the Korean Organ Transplant Registry.

Previous studies regarding donor-recipient size and sex matching in heart transplantation (HTx) mainly included Caucasians with only a small portion of Asians. Even predicted heart mass (PHM) has not yet been elucidated in Asians. We evaluated the association between donor-recipient sex and size matching, including mismatching by PHM, and post-heart transplant survival in Korea. We enrolled 660 adult HTx recipients between January 2014 and December 2020 using the Korean Organ Transplant Registry data. Recipients were categorized based on donor-recipient PHM, body weight, and sex matching. The primary outcome was 1-year mortality and retransplantation after HTx and survival analyses were performed using Kaplan-Meier method and Cox proportional hazard models. Among 660 patients, 74 (11.2%), 404 (61.2%), and 182 (27.6%) received undersized (<-15%), matched (-15% to 20%), and oversized (>20%) hearts by PHM, respectively. Size mismatching by PHM was present in a large number of sex-mismatched patients with 85.1% of male donor-female recipients being classified as oversized by PHM and 62.2% of female donor-male recipients being classified as undersized by PHM. Recipients of undersized or oversized hearts by PHM showed an increased 1-year mortality compared with recipients of matched-size hearts (14.8% versus 9.7%; log-rank p=0.038). The increased mortality persisted after adjusting for other factors affecting mortality (hazard ratio=1.60, 95% confidence interval: 1.01-2.56). These associations were not shown in obese recipients (body mass index ≥25 kg/m2). Heart size mismatching by body weight (log-rank p=0.332) or sex mismatching (all, log-rank p > 0.05) did not predict 1-year mortality after HTx. Heart size matching by PHM, not by body weight or sex, was associated with increased 1-year mortality after HTx in Korea.

Evaluating predicted heart mass in adolescent heart transplantation.

Predicted Heart Mass (PHM) has emerged as an attractive size matching metric in adult cardiac transplantation. However, since PHM was derived from a healthy adult cohort, its generalizability to the pediatric population is unclear. We hypothesize that PHM can be extended to older adolescents, and potentially broaden the donor pool available to this group. The United Network for Organ Sharing database was retrospectively analyzed for patients aged 13 to 18 undergoing heart transplantation. Recipients were divided into quintiles (Q1-Q5) based on donor-to-recipient predicted heart mass ratios (PHMR). Primary end-point was graft survival at 5 years. Two thousand sixty-one adolescent heart transplant recipients between January 1994 and September 2019 were retrospectively analyzed. The median PHMR's for each quintile was 0.84 (0.59-0.92), 0.97 (0.92-1.02), 1.08 (1.02-1.14), 1.21 (1.14-1.30), and 1.44 (1.30-2.31). Kaplan-Meier survival curves demonstrated comparable survival across all quintiles of PHMR (p=0.9). Multivariate Cox regression showed no significant difference in graft failure of the outer quintiles when compared to the middle quintile (Q1: 1.04 HR, p=0.80; Q2: 1.02 HR, p=0.89; Q4: 1.19 HR, p=0.28; Q5: 1.02 HR, p=0.89). Significant covariates included transplant year (HR: 0.95, p < 0.0001), serum bilirubin (HR: 1.04, p=0.0004), ECMO at transplantation (HR: 2.85, p < 0.0001), and underlying diagnosis of dilated cardiomyopathy (vs congenital heart disease, HR: 0.66, p=0.0004). Matching by PHM is not associated with survival or risk in adolescent heart transplant recipients. Our results underscore the ongoing need to develop an improved size-matching method in pediatric heart transplantation.