Cardiac size and sex-matching in heart transplantation : size matters in matters of sex and the heart

Prevalence and Risk Factors of Post-heart Transplant Tricuspid Regurgitation

BACKGROUND

Tricuspid valve regurgitation (TR) is a common sequela immediately after heart transplantation, and its occurrence has decreased after the adoption of the bicaval anastomosis technique. However, the fate of the tricuspid valve in patients undergoing heart transplantation using the bicaval technique is uncertain.

METHODS

We identified patients who underwent orthotopic heart transplantation with bicaval technique at our institution between January 2001 and December 2018. Changes in TR on transthoracic echocardiography from the immediately posttransplantation period until 10 y posttransplant were investigated.

RESULTS

A total of 475 consecutive patients (mean age, 49.1 ± 12.7 y; 153 females) who underwent heart transplantation and followed-up for a median of 74.0 mo (interquartile range, 39.5-118.1) were examined. The severities of TR immediately after heart transplantation were less than mild in 194 patients (40.8%), mild in 253 patients (53.3%), moderate in 20 patients (4.2%), and severe in 8 patients (1.7%). The rates of significant TR at 1 mo, 1 y, 3 y, and 5 y were 4.6% (22 of 475), 2.0% (9 of 459), 1.6% (6 of 387), and 1.4% (4 of 289), respectively. Generalized mixed-effects model showed that the TR decreased over time within 1 y (odd ratio, 0.08; 95% confidence interval, 0.02-0.32; P < 0.001) and increased thereafter (odds ratio, 1.37; 95% confidence interval, 1.19-1.58; P < 0.001). There were no patients who required surgical tricuspid valve intervention.

CONCLUSIONS

In patients undergoing heart transplantation with the bicaval technique, significant TR was less common than the rates reported in previous studies and showed a trend of improvement within a year after surgery.

Can Seismocardiogram Fiducial Points Be Used for the Routine Estimation of Cardiac Time Intervals in Cardiac Patients?

The indexes of cardiac mechanics can be derived from the cardiac time intervals, CTIs, i.e., the timings among the opening and closure of the aortic and mitral valves and the Q wave in the ECG. Traditionally, CTIs are estimated by ultrasound (US) techniques, but they may also be more easily assessed by the identification of specific fiducial points (FPs) inside the waveform of the seismocardiogram (SCG), i.e., the measure of the thorax micro-accelerations produced by the heart motion. While the correspondence of the FPs with the valve movements has been verified in healthy subjects, less information is available on whether this methodology may be routinely employed in the clinical practice for the monitoring of cardiac patients, in which an SCG waveform distortion is expected because of the heart dysfunction. In this study we checked the SCG shape in 90 patients with myocardial infarction (MI), heart failure (HF), or transplanted heart (TX), referred to our hospital for rehabilitation after an acute event or after surgery. The SCG shapes were classified as traditional (T) or non-traditional (NT) on whether the FPs were visible or not on the basis of nomenclature previously proposed in literature. The T shape was present in 62% of the patients, with a higher ∓ prevalence in MI (79%). No relationship was found between T prevalence and ejection fraction (EF). In 20 patients with T shape, we checked the FPs correspondence with the real valve movements by concomitant SCG and US measures. When compared with reference values in healthy subjects available in the literature, we observed that the Echo vs. FP differences are significantly more dispersed in the patients than in the healthy population with higher differences for the estimation of the mitral valve closure (−17 vs. 4 ms on average). Our results indicate that not every cardiac patient has an SCG waveform suitable for the CTI estimation, thus before starting an SCG-based CTI monitoring a preliminary check by a simultaneous SCG-US measure is advisable to verify the applicability of the methodology.

Matching Donor and Recipient Size in Pediatric Heart Transplantation

Previous analyses in pediatric heart transplant (HT) recipients using weight or height have not found donor-recipient size-mismatch to be associated with post-transplant mortality. A recent study in 3,215 normal US children developed an equation for left ventricular (LV) mass using body surface area (BSA). We assessed whether donor-recipient size match using predicted LV mass (PLM) is associated with post-transplant in-hospital mortality or 1-year graft survival. We identified 4,717 children <18 yrs old who received primary HT in the US during 01/2000 to 03/2015 and divided them into five groups [10%, 10%, 60% (reference group), 10% and 10%, respectively] with increasing donor-recipient PLM ratio. In adjusted analysis, group 1 children (PLM ratio ≤.90) were at higher risk of post-transplant in-hospital mortality [Odds Ratio (OR) 1.55, 95% CI 1.04, 2.31]. This association of the most undersized donors with recipient in-hospital mortality was similar when donor-recipient weight ratio<.88 or BSA ratio<.92 (lowest decile) were used instead. There was no difference in 1-year graft survival among groups. Utilizing donors with donor-recipient PLM ratio ≤.90 is associated with higher risk of early post-transplant mortality in pediatric HT recipients. However, this metric is not superior to donor-recipient weight ratio or BSA ratio for assessing size match.

Evaluation of donor heart for transplantation

Cardiac transplantation is considered the gold-standard treatment option for patients suffering from end-stage heart failure refractory to maximum medical therapy. A major determinant of graft function and recipient survival is a comprehensive evaluation of the donor allograft. Challenges arise when designing and implementing an evidence-based donor evaluation protocol due to the number of influential donor-specific characteristics and the complex interactions that occur between them. Here, we present our systematic approach to donor evaluation by examining the impact that relevant donor variables have on graft function and recipient outcomes.

Assessing donor-recipient size metrics for heart transplant outcomes: UNOS database analysis

STUDY

There is no widely accepted donor to recipient size-match metric to predict outcomes in cardiac transplant. The predictive ability of size-match metrics has not been studied when recipients are stratified by heart failure etiology. We sought to assess the performance of commonly used size metrics to predict survival after heart transplant, accounting for restrictive vs. non-restrictive pathology.

METHODS

The UNOS registry was queried from 2000-2017 for all primary isolated heart transplants. Donor-recipient ratios were calculated for commonly used size metrics and their association with survival was assessed using continuous, nonlinear analysis.

RESULTS

29,817 patients were identified. Height (p<0.001), predicted heart mass (PHM) (p = 0.003), ideal body weight (IBW) (p<0.001) and body mass index (BMI) (p = 0.003) ratios were significantly associated with survival, while weight and body surface area (BSA) ratios were not. When stratified, only BMI ratio retained significance for both restrictive (p = 0.051) and non-restrictive (p = 0.003) subsets. Recipients with restrictive etiology had increased risk of mortality with both a lower and higher BMI ratio.

CONCLUSIONS

While many metrics show association with survival in the non-restrictive subset, BMI is the only metric that retains significance in the restrictive subset. Recipients with restrictive and non-restrictive etiologies of heart failure tolerate size mismatch differently. This article is protected by copyright. All rights reserved.

Impact of Obesity on Heart Transplantation Outcomes

Background

Patients with obesity and advanced heart failure face unique challenges on the path to heart transplantation. There are limited data on waitlist and transplantation outcomes in this population. We aimed to evaluate the impact of obesity on heart transplantation outcomes, and to investigate the effects of the new organ procurement and transplantation network allocation system in this population.

Methods and Results

This cohort study of adult patients listed for heart transplant used the United Network for Organ Sharing database from January 2006 to June 2020. Patients were stratified by body mass index (BMI) (18.5–24.9, 25–29.9, 30–34.9, 35–39.9, and 40–55 kg/m²). Recipient characteristics and donor characteristics were analyzed. Outcomes analyzed included transplantation, waitlist death, and posttransplant death. BMI 18.5 to 24.9 kg/m² was used as the reference compared with progressive BMI categories. There were 46 645 patients listed for transplantation. Patients in higher BMI categories were less likely to be transplanted. The lowest likelihood of transplantation was in the highest BMI category, 40 to 55 kg/m² (hazard ratio [HR], 0.19 [0.05–0.76]; P=0.02). Patients within the 2 highest BMI categories had higher risk of posttransplantation death (HR, 1.29; P<0.001 and HR, 1.65; P<0.001, respectively). Left ventricular assist devices among patients in obese BMI categories decreased after the allocation system change (P<0.001, all). After the change, patients with obesity were more likely to undergo transplantation (BMI 30–35 kg/m²: HR, 1.31 [1.18–1.46], P<0.001; BMI 35–55 kg/m²: HR, 1.29 [1.06–1.58]; P=0.01).

Conclusions

There was an inverse relationship between BMI and likelihood of heart transplantation. Higher BMI was associated with increased risk of posttransplant mortality. Patients with obesity were more likely to undergo transplantation under the revised allocation system.

De novo tacrolimus extended-release tablets (LCPT) versus twice-daily tacrolimus in adult heart transplantation: Results of a single-center non-inferiority matched control trial

Extended-release tacrolimus for prophylaxis of allograft rejection in orthotopic heart transplant (OHT) recipients is currently not FDA-approved. One such extended-release formulation of tacrolimus known as LCPT allows once-daily dosing and improves bioavailability compared to immediate-release tacrolimus (IR-tacrolimus). We compared the efficacy and safety of LCPT to IR-tacrolimus applied de novo in adult OHT recipients. Twenty-five prospective recipients on LCPT at our center from 2017 to 2019 were matched 1:2 with historical control recipients treated with IR-tacrolimus based on age, gender, and baseline creatinine. The primary composite outcome of death, acute cellular rejection, and/or new graft dysfunction within 1 year was compared using non-inferiority analysis. LCPT demonstrated non-inferiority to IR-tacrolimus, with a primary outcome risk reduction of 20% (90% CI: -40%, -.5%; non-inferiority P = .001). Tacrolimus trough levels peaked at 2-3 months and were higher in LCPT (median 14.5 vs. 12.7 ng/ml; P = .03) with similar dose levels (LCPT vs. IR-tacrolimus: .08 vs. .09 mg/kg/day; P = .33). Cardiovascular-related readmissions were reduced by 62% (P = .046) in LCPT patients. The complication rate per transplant admission and all-cause readmission rate did not differ significantly. These results suggest that LCPT is non-inferior in efficacy to IR-tacrolimus with a similar safety profile and improved bioavailability in OHT.

A framework for developing sex-specific engineered heart models

The convergence of tissue engineering and patient-specific stem cell biology has enabled the engineering of in vitro tissue models that allow the study of patient-tailored treatment modalities. However, sex-related disparities in health and disease, from systemic hormonal influences to cellular-level differences, are often overlooked in stem cell biology, tissue engineering and preclinical screening. The cardiovascular system, in particular, shows considerable sex-related differences, which need to be considered in cardiac tissue engineering. In this Review, we analyse sex-related properties of the heart muscle in the context of health and disease, and discuss a framework for including sex-based differences in human cardiac tissue engineering. We highlight how sex-based features can be implemented at the cellular and tissue levels, and how sex-specific cardiac models could advance the study of cardiovascular diseases. Finally, we define design criteria for sex-specific cardiac tissue engineering and provide an outlook to future research possibilities beyond the cardiovascular system.

Disparities in heart and lung transplantation

PURPOSE OF REVIEW

Cardiothoracic transplantation is the definitive therapy for end-stage heart and lung disease. In service to this population, disparities in access and care must be simultaneously understood and addressed.

RECENT FINDINGS

There are sex, race, geographic, age, and underlying disease disparities in both heart and lung transplantation. Women have reduced waitlist survival but improved posttransplant survival when compared with men for both heart and lung transplantation. Black patients have worse outcome compared with other races postheart transplant. Geographic disparities impact the likelihood of receiving heart or lung transplant and the growing number of patients with advanced age seeking transplant complicates discussions on survival benefit. Finally, underlying disease has affected outcomes for both heart and lung transplant and now are incorporated into the allocation system.

SUMMARY

Though heart and lung transplantation have several existing disparities, it remains to be seen how advancements in medical technology, changes in donor organ allocation policies, and growing experience in patient selection will impact these concerns.

Differences in Heart Graft Survival by Recipient Sex

Supplemental Digital Content is available in the text.

We aimed to characterize patterns of differences in heart graft failure rates by recipient sex, accounting for modifying effects of donor sex and recipient age.

Pretransplant Right Ventricular Dysfunction Is Associated With Increased Mortality After Heart Transplantation: A Hard Inheritance to Overcome

BACKGROUND

Right ventricular dysfunction (RVD) is a major issue in patients with advanced heart failure because it precludes the implantation of left ventricular assist device, usually leaving heart transplantation (HTx) as the only available treatment option. The pulmonary artery pulsatility index (PAPi) is a hemodynamic parameter integrating information of right ventricular function and of pulmonary circulation. Our aim is to evaluate the association of preoperative RVD, hemodynamically defined as a low PAPi, with post-HTx survival.

METHODS AND RESULTS

Consecutive adult HTx recipient at 2 Italian transplant centers between 2000 and 2018 with available data on pre-HTx right heart catheterization were included retrospectively. RVD was defined as a value of PAPi lower than the 25th percentile of the study population. The association of RVD with the 1-year post-HTx mortality and other secondary end points were evaluated. Multivariate logistic regression was used to adjust for clinical and hemodynamic variables. Analyses stratified by pulmonary vascular resistance (PVR) status (≥3 Woods units vs <3 Woods units) were also performed. Among 657 HTx recipients (female 31.1%, age 53 ± 11 years), patients with pre-HTx RVD (PAPi of <1.68) had significantly lower 1-year survival rates (77.8% vs 87.1%, P = .005), also after adjusting for estimated glomerular filtration rate, total bilirubin, PVR, serum sodium, inotropes, and mechanical circulatory support at HTx (hazard ratio 2.0, 95% confidence interval, 1.3-3.1). RVD was also associated with post-HTx renal replacement therapy (hazard ratio 2.0, 95% confidence interval 1.05-3.30) and primary graft dysfunction (hazard ratio 1.7, , 95% confidence interval 1.02-3.30). When stratifying patients by estimated PVR status, RVD was associated with worse 1-year survival among patients with normal PVR (76.9% vs 88.3%, P = .003), but not in those with increased PVR (78.6% vs 83.2%, P = .49).

CONCLUSIONS

Preoperative RVD, evaluated through PAPi, is associated with mortality and morbidity after HTx, providing incremental prognostic value over traditional clinical and hemodynamic parameters.

Impact of various sizing metrics on female donor to male recipient heart transplant outcomes

BACKGROUND

This study evaluated the impact of various sizing metrics on outcomes of female donor to male recipient orthotopic heart transplantation (OHT).

METHODS

We queried the United Network of Organ Sharing database to analyze all isolated, primary adult OHTs from January 1, 2010 to January 20, 020. Patients were stratified by donor-recipient sex pairing. Logistic regression was used to investigate risk-adjusted effects of current size matching criteria (weight ratio, body mass index [BMI] ratio, predicted heart mass [pHM] ratio) on 1-year posttransplant mortality. Kaplan-Meier analysis was used to compare posttransplant survival among cohorts.

RESULTS

A total of 22,450 patients were analyzed, of which 3019 (13.4%) underwent female-to-male transplantation. Of sex-matched pairs, female-to-male donation had the lowest proportion of undersized hearts using weight and BMI ratio metrics (10.5% and 5.2%) but had the highest proportion of undersizing using pHM metrics (48.1%) (all p < 0.001). Female-to-male recipients had the lowest rate of unadjusted 1-year survival (90.0%, p = 0.0169), and increased hazards of mortality after risk adjustment (odds ratio [OR]: 1.17, 95% confidence interval [CI]: 1.01-1.36, p = 0.034). Undersizing using pHM (donor-recipient ratio <0.85) was the only metric found to be associated in increased mortality after risk adjustment (OR: 1.32, 95% CI: 1.02-1.71, p = 0.035).

CONCLUSION

Female-to-male heart transplantation has the worst survival of all sex-matching combinations. Although female donors in this cohort are appropriately sized using traditional metrics, half are under-sized using pHM. This, combined with its strong association with mortality, underscores the importance of routine pHM assessment when evaluating female donors for male recipients.

Donor-recipient predicted heart mass ratio and right ventricular-pulmonary arterial coupling in heart transplant

OBJECTIVES

Right ventricular-pulmonary arterial (RV-PA) coupling interactions are largely unexplored in heart transplant patients. The outcome of this study was RV-PA coupling at 7 and 30 days after heart transplant and its association with donor-recipient size matching.

METHODS

Clinical, echocardiographic and haemodynamic data from a retrospective cohort of heart transplant recipients and respective donors were reviewed. Coupling between RV-PA was examined by assessing the RV fractional area change and pulmonary artery systolic pressure ratio. Donor-recipient size matching was assessed by the predicted heart mass (PHM) ratio, and groups with a PHM ratio <1 and ≥1 were compared.

RESULTS

Forty-four heart transplant recipients were included in this study (50 years, 57% male sex). Postoperative RV-PA coupling improved from 7 to 30 days (RV fractional area change/pulmonary artery systolic pressure 0.9 ± 0.3 vs 1.2 ± 0.3; P < 0.001). A positive association was found between an adequate PHM ratio and improvement of RV fractional area change/pulmonary artery systolic pressure at 30 days, independent of graft ischaemic time and pre-existent pulmonary hypertension (B coefficient 0.54; 95% confidence interval 0.11-0.97; P = 0.016; adjusted R2 = 0.24).

CONCLUSIONS

These findings highlight the role of PHM as a metric to help donor selection and suggest its impact in RV-PA coupling interactions post-heart transplant.

Ventricular assist device bridging with gender-mismatch increases rejection and decreases survival following a heart transplant

OBJECTIVES

Survival is poor following an orthotopic heart transplant with gender-mismatched donors and recipients. Patients bridged to an orthotopic heart transplant with a ventricular assist device (VAD) frequently become sensitized. We hypothesized that the combination of VAD bridging and gender-mismatch may result in greater rejection and poorer survival.

METHODS

Data were obtained from the United Network of Organ Sharing database. Patients were divided into 4 groups: (i) VAD recipients who received a heart from a gender-matched donor (VAD-M); (ii) VAD recipients who received a heart from a gender-mismatched donor (VAD-MM); (iii) noVAD recipients who received a heart from a gender-matched donor (noVAD-M); and (iv) noVAD recipients who received a heart from a gender-mismatched donor (noVAD-MM). Rejection episodes within 1-year post-transplant and transplant survival were compared in VAD-M versus VAD-MM and noVAD-M versus noVAD-MM groups, respectively.

RESULTS

Between January 2000 and June 2017, of 33 401 adult patients who underwent heart transplants, 8648, 2441, 12 761 and 4992 patients were identified as VAD-M, VAD-MM, noVAD-M and noVAD-MM, respectively. Rejection within 1-year post-transplant occurred in 23.3% and 27.3% of the VAD-M and VAD-MM groups, respectively (P < 0.01) and in 21.8% and 23.6% of the noVAD-M and noVAD-MM groups (P = 0.02), respectively. In an adjusted survival analysis, the VAD-MM group showed significantly worse survival than the VAD-M group (P < 0.01), whereas there was no significant difference between the noVAD-M and noVAD-MM groups (P = 0.21).

CONCLUSIONS

Our results indicated that the combination of VAD bridging and gender-mismatch caused greater rejection and worse survival following a transplant. Further study is necessary to prove comparable post-transplant survival of gender-matched or -mismatched recipients without VAD bridging.

Clinical outcomes of older adults listed for heart transplantation in the United States

OBJECTIVE

To examine if older age (>70 years) should be a relative contraindication for heart transplantation, we evaluated the characteristics and outcomes of patients with age ≥70 years listed for heart transplantation; and whether post-transplantation survival was inferior to younger counterparts.

DESIGN

Retrospective cohort analysis.

SETTING

The scientific registry of transplant recipients (SRTR).

PARTICIPANTS

Adults (≥18 years) listed for heart transplantation in the SRTR between 2000 and 2018.

INTERVENTIONS

Heart transplantation.

MEASUREMENTS

Characteristics and outcomes were compared for adults ≥70 years and <70 years. We evaluated waitlist mortality and post-transplant 1-year and 5-year survivals.

RESULTS

The study included 57,285 patients (age range 18-79 years) listed for heart transplantation; 1203 (2.1%) age ≥70 years. Of these, 37,135 patients underwent heart transplantation; 806 (2.2%) were age ≥70 years. Yearly listing of those age ≥70 years has consistently increased from 2.5% (n = 30) in 2000 to 11% (n = 132) in 2017 (p < 0.01). As compared with the age <70 years group, those ≥70 years had a similar risk of death while waiting (sub-hazard ratio [SHR] 0.86, 95% confidence interval [HR] 0.68-1.08; p = 0.19) but were more likely to be transplanted (SHR 1.36, 95% CI 1.26-1.48; p < 0.01). Among the older patients, the overall post-transplant 1- and 5-year mortality rate was 10.4% and 19.2%, respectively. Older recipients had lower unadjusted survival compared with younger recipients (log-rank p = 0.03). However, after adjustment for relevant covariates, there was no significant difference in 5-year mortality between both groups (HR 1.06, 95% CI 0.91-1.254; p = 0.43).

CONCLUSIONS

Post-transplant survival up to 5 years among patients of age ≥70 years was similar to that of younger recipients. Older patients who received heart transplantation appear to have lower risk features but receive hearts from higher risk donors. Chronologic age alone should not constitute a contraindication for heart transplantation, although careful patient selection criteria should be applied.

Sex and Heart Failure Treatment Prescription and Adherence

Heart disease is the leading cause of death in both men and women in developed countries. Heart failure (HF) contributes to significant morbidity and mortality and continues to remain on the rise. While advances in pharmacological therapies have improved its prognosis, there remain a number of unanswered questions regarding the impact of these therapies in women. Current HF guidelines recommend up-titration of neurohormonal blockade, to the same target doses in both men and women but several factors may impair achieving this goal in women: more adverse drug reactions, reduced adherence and even lack of evidence on the optimal drug dose. Systematic under-representation of women in cardiovascular drug trials hinders the identification of sex differences in the efficacy and safety of cardiovascular medications. Women are also under-represented in device therapy trials and are 30% less likely to receive a device in clinical practice. Despite presenting with fewer ventricular arrythmias and having an increased risk of implant complications, women show better response to resynchronization therapy, with lower mortality and HF hospitalizations. Fewer women receive advanced HF therapies. They have a better post-heart transplant survival compared to men, but an increased immunological risk needs to be acknowledged. Technological advances in mechanical circulatory support, with smaller and more hemocompatible devices, will likely increase their implantation in women. This review outlines current evidence regarding sex-related differences in prescription, adherence, adverse events, and prognostic impact of the main management strategies for HF.

The impact of donor sex on heart transplantation outcomes-a study of over 60,000 patients in the United States

BACKGROUND

The impact of donor sex on heart transplantation outcomes irrespective of recipient sex remains unclear. The objective of this study was to evaluate the impact of donor sex on heart transplantation outcomes in the United States.

METHODS

From 1987 to March 2019, 63,775 adult patients who underwent heart transplantation were matched to 27,509 male and 11,474 female donors in the United States. Data were prospectively collected by the United Network for Organ Sharing (UNOS). Patients without missing data were stratified by donor sex and donor menopause status. The groups were matched 1:1 using the propensity score of each patient. Kaplan-Meier survival and cox proportional hazards regression analyses were performed. The primary endpoint was all-cause mortality. Secondary endpoints were postoperative complications.

RESULTS

Propensity matching generated 15,506 and 1,094 patients based on donor sex and menopause status, respectively. Recipients who received female donor allografts were more likely to have acute rejection episodes requiring anti-rejection medical treatment (11.9% vs 10.1%, p = .007) and require post-transplant dialysis (10.9% vs 9.3%, p = .001) than those who received male donor allografts. Overall survival using female vs male donor allografts was similar (p = .34). Recipients who received pre- vs post-menopausal female donor hearts had similar postoperative outcomes and overall survival (p = .23).

CONCLUSIONS

Analysis of the UNOS database showed similar median survival using female vs male donor hearts in adult heart transplantation, irrespective of donor menopause status. Female donor allografts are used far less frequently, thus these results represent an opportunity to maximize usage by better utilization of suitable female donor organs.

Influence of Sex-Mismatch on Prognosis After Heart Transplantation

The influence of donor and recipient sex on prognosis after heart transplantation has been analyzed in single, multi-center studies, and international registries. In most of them, sex-mismatch was identified as a risk factor for the worst prognosis, especially in men recipients of female heart. This could be attributed to physiological differences between women and men, differences in complications rates after heart transplantation (rejection, cardiovascular allograft vasculopathy, and primary graft failure), and pulmonary hypertension of the recipient. Confounding variables as age, urgent transplantation, and size-mismatch should also be considered. When allocating a graft, sex-mismatch should be considered but its influence in long-term survival should be further explored.

Heart Transplantation From Brain Dead Donors: A Systematic Review of Animal Models

Despite advances in mechanical circulatory devices and pharmacologic therapies, heart transplantation (HTx) is the definitive and most effective therapy for an important proportion of qualifying patients with end-stage heart failure. However, the demand for donor hearts significantly outweighs the supply. Hearts are sourced from donors following brain death, which exposes donor hearts to substantial pathophysiological perturbations that can influence heart transplant success and recipient survival. Although significant advances in recipient selection, donor and HTx recipient management, immunosuppression, and pretransplant mechanical circulatory support have been achieved, primary graft dysfunction after cardiac transplantation continues to be an important cause of morbidity and mortality. Animal models, when appropriate, can guide/inform medical practice, and fill gaps in knowledge that are unattainable in clinical settings. Consequently, we performed a systematic review of existing animal models that incorporate donor brain death and subsequent HTx and assessed studies for scientific rigor and clinical relevance. Following literature screening via the U.S National Library of Medicine bibliographic database (MEDLINE) and Embase, 29 studies were assessed. Analysis of included studies identified marked heterogeneity in animal models of donor brain death coupled to HTx, with few research groups worldwide identified as utilizing these models. General reporting of important determinants of heart transplant success was mixed, and assessment of posttransplant cardiac function was limited to an invasive technique (pressure-volume analysis), which is limitedly applied in clinical settings. This review highlights translational challenges between available animal models and clinical heart transplant settings that are potentially hindering advancement of this field of investigation.

Donor and Recipient Size Matching in Heart Transplantation With Predicted Heart and Lean Body Mass

Donor and recipient size matching during heart transplant can be assessed using weight or predicted heart mass (PHM) ratios. We developed sex-specific allomteric equations for PHM and predicted lean body mass (PLBM) using the United Kingdom Biobank (UKB) and evaluated their predictive value in the United Network of Organ Sharing database. Donor and recipient size matching was based on weight, PHM and PLBM ratios. PHM was calculated using the Multiethnic Study of Atherosclerosis and UKB equations. PLBM was calculated using the UKB and National Health and Nutrition Examination Survey equations. Relative prognostic utility was compared using multivariable Cox analysis, adjusted for predictors of 1-year survival in the Scientific Registry of Transplant Recipients model. Of 53,648 adult patients in the United Network of Organ Sharing database between 1996 and 2016, 6528 (12.2%) died within the first year. In multivariable analysis, undersized matches by any metric were associated with increased 1-year mortality (all P < 0.01). Oversized matches were at increased risk using PHM or PLBM (all P < 0.01), but not weight ratio. There were significant differences in classification of size matching by weight or PHM in sex-mismatched donor-recipient pairs. A significant interaction was observed between pulmonary hypertension and donor undersizing (hazard ratio 1.15, P = 0.026) suggesting increased risk of undersizing in pulmonary hypertension. Donor and recipient size matching with simplified PHM and PLBM offered an advantage over total body weight and may be more important for sex-mismatched donor-recipient pairs. Donor undersizing is associated with worse outcomes in patients with pulmonary hypertension.

Size matching in heart transplantation: Is predicted heart mass the optimal method in a United Kingdom cohort?

Predicted heart mass (PHM) equations have been proposed as an alternative method for size matching in heart transplantation. We assessed association between donor-recipient size mismatch, defined using PHM equations, and survival post-heart transplant in the United Kingdom. Data from all adult patients who received a heart transplant between 1995 and 2017 were obtained from the United Kingdom Transplant Registry. PHM was calculated using published equations. Primary outcome was 1-year survival post-heart transplantation. Recipients of undersized organs had reduced 1-year survival (HR 1.31, 95% CI 1.03-1.67, p = .03). Oversizing had no impact on survival (HR 0.99, 95% CI 0.78-1.26, p = .96). Gender mismatching had no impact on survival in the cohort matched by PHM (HR 1.12, 95% CI 0.86-1.47, p = .4). In recipients without pulmonary hypertension, undersizing by PHM had no impact on 1-year survival (HR 0.95, 95% CI 0.61-1.49, p = .83). In recipients with pulmonary hypertension, oversizing donor RV by using PHM RV equation (PHM_RV ) results in improved survival at 1 year (HR 0.65, 95% CI 0.5-0.83, p = .001). In conclusion, receiving an organ undersized by PHM was associated with decreased 1-year survival. Subgroup analyses demonstrated that undersizing only impacted survival in recipients with pulmonary hypertension and that these recipients had improved outcomes if they received an organ with an RV oversized by >10% by PHM_RV .

Donor-recipient Matching in Heart Transplantation

Heart transplantation remains the treatment of choice for end-stage Heart Failure (HF). Due to the shortage of organs for transplantation and the occurrence of perioperative complications, a key problem is donor matching, which should result in increased survival and improved quality of life for patients. The success of this procedure depends on various parameters such as gender, weight, ABO blood group and Human Leukocyte Antigen (HLA) system of both the recipient and the donor. Furthermore, non-HLA antigens may also be valuable in donor-recipient matching. The aim of this article is to summarize the recent knowledge on the impact of various factors on accurate donor-recipient matching to heart transplantation.

Right ventricular undersizing is associated with increased 1-year mortality

OBJECTIVES

Right heart hemodynamic management is critical, because many post-heart transplantation (HTx) complications are related to right ventricular (RV) failure. However, current guidelines on size and sex matching rely primarily on weight matching, with recent literature using total ventricular mass (TVM), which places less emphasis on the impact of RV mass (RVM) matching. The aim of the present study was to analyze the relationship of RVM matching and survival after HTx.

METHODS

We performed the retrospective analysis using the UNOS database of adult HTx performed between January 1997 and December 2017. Previously validated equations were used to calculate TVM and RVM. The percent difference in ventricular mass in the donor and recipient pair was used for the size mismatch. All donor-recipient pairs were divided into 4 RVM groups by their mismatch ratio. We analyzed RVM matching and explored how RVM undersizing impacted outcomes. The primary outcome measure was 1-year survival; secondary outcomes measured included stroke and dialysis within 1 year and functional status.

RESULTS

A total of 38,740 donor-recipient pairs were included in our study. The 4 RVM match groupings were as follows: <0%, 0% to 20%, 20% to 40%, and >40%. Utilization of donors who were older and of female sex resulted in greater RVM undersizing. Survival analysis demonstrated patients with RVM undersizing had worse 1-year survival (P < .001). RVM undersizing was an independent predictor of higher 1-year mortality (hazard ratio, 1.23; 95% confidence interval, 1.11 to 1.34; P < .001). RVM undersizing was also associated with higher rates of dialysis within 1-year of transplantation and poorer postoperative functional status.

CONCLUSIONS

RVM undersizing is an independent predictor for worse 1-year survival. Donors who are older and female have lower absolute predicted RVM and may be predisposed to RVM undersizing. RVM-undersized transplantation requires careful risk/benefit considerations.

Gender differences in heart transplantation: Twenty-five year trends in the nationwide Spanish heart transplant registry

The study of gender differences may lead into improvement in patient care. We have aimed to identify the gender differences in heart transplantation (HT) of adult HT recipients in Spain and their evolution in a study covering the years 1993-2017 in which 6740 HT (20.6% in women) were performed. HT indication rate per million inhabitants was lower in women, remaining basically unchanged during the 25-year study period. HT rate was higher in men, although this decreased over the 25-year study period. Type of heart disease differed in men versus women (p < .001): ischemic heart disease 47.6% versus 22.5%, dilated cardiomyopathy 41.3% versus 34.6%, or other 36% versus 17.8%, respectively. Men were more frequently diabetics (18% vs. 13.1% p < .001), hypertensives (33.1% vs. 24% p < .001), and smokers (21.7% vs. 12.9% p < .001), respectively. Women had more pre-HT malignancies (7.1% vs. 2.8% p < .001), and their clinical status was worse at HT due to renal function and mechanical ventilation. Adjusted survival (p = .198) and most of the mortality-related variables were similar in men and women. Death occurred more frequently in women due to rejection (7.9% vs. 5.1% p < .001) and primary failure (18.2% vs. 12.5% p < .001) and in men due to malignancies (15.1% vs. 6.6% p < .001).

How Big Is Too Big?: Donor Severe Obesity and Heart Transplant Outcomes

BACKGROUND

As the population becomes increasingly obese, so does the pool of potential organ donors. We sought to investigate the impact of donors with body mass index ≥40 (severe obesity) on heart transplant outcomes.

METHODS

Single-organ first-time adult heart transplants from 2003 to 2017 were evaluated from the United Network for Organ Sharing database and stratified by donor severe obesity status (body mass index ≥40). Demographics were compared, and univariate and risk-adjusted analyses evaluated the relationship between severe obesity and short-term outcomes and long-term mortality. Further analysis evaluated the prevalence of severe obesity within the pool of organ donation candidates.

RESULTS

A total of 26 532 transplants were evaluated, of which 939 (3.5%) had donors with body mass index ≥40, with prevalence increasing over time (2.2% in 2003, 5.3% in 2017). Severely obese donors more likely had diabetes mellitus (10.4% versus 3.1%, P<0.01) and hypertension (33.3% versus 14.8%, P<0.01), and 67.4% were size mismatched (donor weight >130% of recipient). Short-term outcomes were similar, including 1-year survival (10.6% versus 10.7%), with no significant difference in unadjusted and risk-adjusted long-term survival (log-rank P=0.67, hazard ratio, 0.928, P=0.30). Organ donation candidates also exhibited an increase in severe obesity over time, from 3.5% to 6.8%, with a lower proportion of hearts from severely obese donors being transplanted (19.5% versus 31.6%, P<0.01).

CONCLUSIONS

Donor severe obesity was not associated with adverse post-transplant outcomes. Increased evaluation of hearts from obese donors, even those with body mass index ≥40, has the potential to expand the critically low donor pool.

The Year in Cardiothoracic Transplantation Anesthesia: Selected Highlights from 2019

The highlights in cardiothoracic transplantation focus on the recent research pertaining to heart and lung transplantation, including expansion of the donor pool, the optimization of donors and recipients, the use of mechanical support, the perioperative and long-term outcomes in these patient populations, and the use of transthoracic echocardiography to diagnose rejection.

Long-term Survival After Heart Transplantation: A Population-based Nested Case-Control Study

BACKGROUND

Heart transplantation is the mainstay of treatment for patients in end-stage heart failure. This study sought to contrast survival after transplantation with that of the general population to quantify standardized mortality rates using a nested case-control study design.

METHODS

Control subjects were noninstitutionalized inhabitants of the United States identified through the National Longitudinal Mortality study. Case subjects were adults who underwent heart transplantation between 1990 and 2007 and identified through the Organ Procurement and Transplantation Network. Propensity-matching (5:1, nearest neighbor, caliper = 0.1) was utilized to identify suitable control subjects based on age, sex, race, and state of permanent residency. The primary study endpoint was 10-year survival.

RESULTS

In all, 31,883 heart transplant recipients were matched to 159,415 noninstitutionalized residents of the United States. The 10-year survival of heart transplant recipients was 53%. The population expected mortality rate was 15.9 deaths per 100 person-years with an observed rate of 45.1 deaths per 100 person-years (standardized mortality rate [SMR] 2.84; 95% confidence interval, 2.82 to 2.87). The broadest gaps between observed and expected survival were evident in female (SMR 3.63), black (SMR 3.67), and Hispanic (SMR 4.12) recipients. Standardized mortality ratios declined over time (1990 to 1995, 3.09; 1996 to 2000, 2.90; 2001 to 2007, 2.58). The long-term standardized survival of older recipients was closest to that expected for their age.

CONCLUSIONS

Heart transplant recipients have considerable long-term survival and have a threefold higher standardized long-term mortality rate than that of the noninstitutionalized population. Long-term mortality rates have consistently declined over time and will likely continue to decrease.

Post-transplant survival in adult congenital heart disease patients as compared to dilated and ischemic cardiomyopathy patients; an analysis of the thoracic ISHLT registry

Previous studies have shown that adult congenital heart disease (ACHD) is associated with high early post-transplant mortality but improved long-term survival in comparison to the overall heart transplant population. We aimed to evaluate survival outcomes of ACHD in adult transplant recipient patients as specifically compared to ischemic (ICM) and dilated cardiomyopathy (DCM) groups. Adult heart transplant recipients between 2004 and 2014 were identified from the ISHLT registry. We used Kaplan-Meier analysis to evaluate overall survival, 1-year survival, and 1-year conditional survival among etiology groups and multivariable Cox proportional hazard (PH) models to assess the association between etiology of cardiomyopathy and 1-year and long-term all-cause mortality and cause-specific mortality. We included 30 130 heart transplant recipients. One-year survival was 78.3% in ACHD, 84.3% in ICM, and 86.2% in DCM patients (P < .001). By multivariable analysis, during first post-transplant year, ACHD and ICM patients were at significantly higher mortality risk than DCM. Adjusted post-transplant mortality risk, conditional on 1-year survival, was not statistically different in ACHD and DCM while ICM patients had 17% higher long-term mortality risk than DCM patients leading to overall worse outcomes in ICM patients. Therefore, ICM patients have poorer outcomes in comparison to both DCM and ACHD patients.

Update and breakthrough in cardiac xenotransplantation

PURPOSE OF REVIEW

Considerable advancements have been made in the field of cardiac xenotransplantation in the recent years, achieving prolonged survival of the life-supporting cardiac xenograft and paving the way toward first clinical implications.

RECENT FINDINGS

The combination of genetic modifications and novel immunosuppression with costimulation blockade, as well as supporting therapy with antiinflammatory treatment, growth prevention, and adaptation of the heart procurement system to reduce myocardial ischemia and reperfusion injury improves the overall cardiac xenograft function and overall survival in nonhuman primates. Through the newly identified xenoantigens and novel gene-editing techniques, further genetic modification of the porcine xenografts should be explored, to ensure clinical safety.

SUMMARY

With continuous progress in all fields of cardiac xenotransplantation, first clinical use in humans seems accomplishable. To ensure the clinical safety and to conform to the ethical regulations, further investigation of the infectious and immunological implications on humans should be explored prior to first clinical use. The first clinical use of cardiac xenotransplantation will be limited to only highly selected patients.

Morphometric analysis of alpha-1, 3-galactosyltransferase knockout pig kidney and heart

We report a morphometric evaluation of α1,3-galactosyltransferase knockout (GTKO) pig heart and kidney (n = 9) at the end of one, three and seven months. Organs parameters gradually increased with the age (p < 0.05) and body weight (p < 0.05) of the pigs. Organs morphometries were significantly correlated to the age and body weight of the animal. We were able to conclude the average size of GTKO pig heart and kidney based on age and body weight, which could be helpful in estimating the size of these organs non-invasively for transplantation.

Volumetrics and fit assessments for donor to recipient size matching in pediatric heart transplantation: Is it time for a new paradigm?

Pediatric heart transplant patients face the highest waitlist mortality in solid organ transplantation. Given the relatively fixed number of donor organs becoming available each year, improving donor organ utilization could potentially have significant impact on reducing waitlist mortality. Donor to recipient weight ratio has historically been used to identify suitable donors; however, this method does not take into account the potential for significant variance in heart size due to complex congenital heart disease or underlying cardiomyopathy. We believe, based on our experience to date, that donor matching based upon weight ratios should be augmented by improved methodologies that provide a more accurate assessment of heart volumes. Herein we describe the rationale for these methodologies and our single-center experience using volumetrics as an alternative for donor fit assessments.

Increasing Heart Transplant Volume by Expansion of Donor Heart Selection Criteria: A Single-Center Analysis

BACKGROUND

Our transplant center recently expanded the acceptance criteria for cardiac donors to increase heart transplant volume. Our purpose was to assess the success of this strategy while maintaining acceptable 1-year survival.

METHODS

We retrospectively reviewed patients who underwent heart transplantation at our institution from January 2011 through December 2017. This time period was divided into 2 periods: 2011 to 2014 (Period A) and 2015 to 2017 (Period B) because we implemented our new donor acceptance policy at the onset of 2015. We compared recipient and donor characteristics from the 2 time periods. The primary outcomes were 1-year graft and patient survival.

RESULTS

Transplant volume increased in Period B with the expanded donor acceptance policy: 128 heart transplants over 36 months compared to 52 transplants in 48 months in Period A. Mean (± SD) recipient age was significantly higher in Period B (54 ± 12 vs 50 ± 15 years; P = .04) whereas other recipient variables were similar. Donors in Period B were significantly older, more likely to be female, had larger body mass index, were located a greater distance from the transplant center, and had a higher sequence number. Female donor to male recipient occurred more often in Period B than in Period A (27% vs 10%; P = .01). Both 1-year patient survival and graft survival were unchanged between Period B (95% for both) and Period A (96% for both).

CONCLUSIONS

Using a more aggressive donor acceptance policy allowed for an increase in heart transplant volume while maintaining acceptable 1-year graft and patient survival.

Predicted heart mass-based size matching among recipients with moderate pulmonary hypertension: Outcomes and sex effect

BACKGROUND

There is a lack of evidence to guide appropriate donor sizing in recipients with moderate pulmonary hypertension (pHTN) awaiting heart transplantation (HTx). It is common practice to oversize donor hearts for such recipients to prevent post-operative right ventricular failure. Therefore, our objective was to determine if oversizing in pre-transplant moderate pHTN provides a survival advantage.

METHODS

The United Network for Organ Sharing database was analyzed to include HTx recipients from 1994 to 2016. Recipients were considered as having moderate pHTN if the pulmonary vascular resistance (PVR) was 2.5 to 5 Wood units (WU) or transpulmonary gradient (TPG) was 10 to 18 mm Hg. Heart size mismatch was determined using the predicted heart mass equations. A size mismatch of ≥15% in either direction was considered undersized or oversized, respectively. Ninety-day and 1-year survival were analyzed based on size matching via univariate and Cox regression analysis. Propensity matching was performed to specifically evaluate the effect of donor sex among male transplant recipients.

RESULTS

Among 29,441 HTx recipients, 10,666 had moderate pHTN by PVR criteria and 12,624 HTx patients had moderate pHTN according to TPG criteria. Among patients with a PVR of 2.5 to 5 WU, oversizing was not associated with lower mortality compared with matched hearts at 90 days (7.6% vs 7.4%; p = 0.75) and 1 year (12.1% vs 11.3%; p = 0.26). Conversely, undersizing the donor was associated with a higher 90-day (10.6% vs 7.6% vs 7.4%; p < 0.01) and 1-year (15.3% vs 12.1% vs 11.3%; p < 0.01) mortality than recipients receiving oversized or matched hearts, respectively. On Cox regression analysis, there was no benefit with oversizing at 90 days (hazard ratio [HR] 0.88; p = 0.23) and 1 year (HR 0.99; p = 0.90), whereas undersizing was associated with higher 90-day (HR 1.32; p = 0.02) and 1-year mortality (HR 1.23; p = 0.03) compared to size-matched controls. Among patients with moderate pHTN based on TPG of 10 to 18 mm Hg, neither undersizing nor oversizing was predictive of mortality at 90 days and 1 year according to Cox regression analysis. Propensity matching revealed that female-to-male transplantation had similar 1-year mortality to male-to-male transplantation, and there was no advantage to oversizing female donors for male recipients.

CONCLUSIONS

In this registry-based analysis, there was no benefit to oversizing donors for cardiac transplant recipients with moderate pHTN. Elimination of this restriction could increase the donor pool and reduce wait times for such recipients.

Benefits of the Modified Bicaval Anastomosis Technique for Orthotopic Heart Transplantation From a Size-Mismatched Marginal Donor

BACKGROUND

Size-mismatched heart transplantation (HTx) is associated with a risk of stenosis of the caval anastomosis site or low cardiac output syndrome. We developed a modified bicaval anastomosis technique (mBCAT) that achieved an adjustable caval anastomosis to compensate for size mismatch. This study was performed to validate the rationale of the mBCAT for size-mismatched HTx.

METHODS AND RESULTS

This institutional consecutive series involved 106 patients who underwent HTx with the mBCAT during an 18-year period. The cohort was divided into 3 groups according to the donor-to-recipient body weight ratio: <0.8, undersized group (n=17); 0.8-1.3, size-matched group (n=68); and >1.3, oversized group (n=21); outcomes were compared. The undersized, size-matched, and oversized groups showed no significant differences in the rate of mild or worse echocardiographic tricuspid regurgitation at 1 month [1 (5.8%), 7 (10.2%), and 1 (4.8%), respectively; P=0.87] or the survival rate at 10 years [100%, 93.9%, and 100%, respectively; P=0.25]. The right heart catheter study revealed no pressure gradient across the orifices of both cavae in any patient. Additionally, the cardiac index immediately post-HTx was significantly low in the undersized group (P=0.008), but was similar to the other groups at 6 months post-HTx (P=0.16).

CONCLUSIONS

The mBCAT prevented caval anastomosis-related complications in size-mismatched HTx and achieved excellent hemodynamics regardless of donor size.

Donor and Recipient Characteristics in Heart Transplantation Are Associated with Altered Myocardial Tissue Structure and Cardiac Function

PURPOSE

To use structure-function cardiac MRI in the evaluation of relationships between donor and heart transplantation (HTx) recipient characteristics and changes in cardiac tissue structure and function. HTx candidates and donor hearts are evaluated for donor-recipient matches to improve survival, but the impact of donor and recipient characteristics on changes in myocardial tissue and function in the transplanted heart is not fully understood.

MATERIALS AND METHODS

Cardiac MRI at 1.5 T was performed from August 2014 to June 2017 in 58 HTx recipients (mean age, 51.1 years ± 12.6 [standard deviation], 26 female patients) and included T2 mapping (to evaluate edematous and/or inflammatory changes), precontrast and postcontrast T1 mapping (allowing the calculation of extracellular volume fraction [ECV] to estimate interstitial expansion), and tissue phase mapping (allowing the calculation of myocardial velocities and twist). Donor and recipient demographics (age, sex, height, weight, and body mass index [BMI]) and comorbidities (hypertension, diabetes, and smoking history) were evaluated for relationships with cardiac MRI measures.

RESULTS

Sex-influenced cardiac MRI measures of myocardial tissue and function are as follows: Female HTx recipients demonstrated increased precontrast T1 (P = .002) and reduced systolic peak long-axis velocities (P = .015). Increased age of the donor heart was associated with elevated T2 (r = 0.32; P < .05) and ECV (r = 0.47; P < .01), indicating increased edema and interstitial expansion, as well as impaired diastolic peak long-axis velocities (r = 0.41; P < .01). Recipient-donor differences in age, weight, and BMI were significantly associated with elevated ECV (r = 0.36-0.48; P < .05). Hypertension in donors resulted in increased ECV (31.0% ± 4.2 vs 26.0% ± 3.3; P = .001).

CONCLUSION

Donor and HTx recipient characteristics were significantly associated with cardiac MRI-derived measures of myocardial tissue structure and function.© RSNA, 2019.

Validation of Cardiovascular Magnetic Resonance-Derived Equation for Predicted Left Ventricular Mass Using the UK Biobank Imaging Cohort: Tool for Donor-Recipient Size Matching

BACKGROUND

Current guidance from International Society for Heart and Lung Transplantation recommends using body weight for donor-recipient size matching for heart transplantation. However, recent studies have shown that predicted heart mass, using body weight, height, age, and sex, may represent a better method of size matching. We aim to validate a cardiovascular magnetic resonance (CMR)-derived equation for predicted left ventricular mass (LVM) in a cohort of normal individuals in the United Kingdom.

METHODS

This observational study was conducted in 5065 middle-aged (44-77 years old) UK Biobank participants who underwent CMR imaging in 2014 to 2015. Individuals with cancer diagnosis in the previous 12 months or history of cardiovascular disease were excluded. Predicted LVM was calculated based on participants' sex, height, and weight recorded at the time of imaging. Correlation analyses were performed between the predicted LVM and the LVM obtained from manual contouring of CMR cine images. The analysis included 3398 participants (age 61.5±7.5 years, 47.8% males).

RESULTS

Predicted LVM was considerably higher than CMR-derived LVM (mean±SD of 138.8±28.9 g versus 86.3±20.9 g). However, there was a strong correlation between the 2 measurements (Spearman correlation coefficient 0.802, P<0.0001).

CONCLUSIONS

Predicted LVM calculated using a CMR-derived equation that incorporates height, weight, and sex has a strong correlation with CMR LVM in large cohort of normal individuals in the United Kingdom. Our findings suggest that predicted heart mass equations may be a valid tool for donor-recipient size matching for heart transplantation in the United Kingdom.

Sex Differences in Advanced Heart Failure Therapies

This in-depth review of sex differences in advanced heart failure therapy summarizes the existing literature on implantable cardioverter defibrillators, biventricular pacemakers, mechanical circulatory support, and transplantation with a focus on utilization, efficacy/clinical effectiveness, adverse events, and controversies. One will learn about the controversies regarding efficacy/clinical effectiveness of implantable cardioverter defibrillators and understand why these devices should be implanted in women even if there are sex differences in appropriate shocks. Individuals will learn about the sex differences with biventricular pacemakers with respect to ventricular remodeling and reduction in heart failure hospitalizations/mortality, as well as, possible mechanisms. We will demonstrate sex differences in heart transplantation and waitlist survival. Despite similar survival for women and men with left ventricular assist devices, there are sex differences in adverse events. These devices do successfully bridge women and men to transplant, yet women are less likely than men to have a left ventricular assist at time of listing and time of transplantation. Finally, one will learn about the concerns regarding poor outcome for men who receive female donor hearts and discover this may not be due to sex, but rather size. More research is needed to better understand sex differences and further improve advanced heart failure therapy for both women and men.