Survival Outcomes After Heart Transplantation: Does Recipient Sex Matter?

Sex and Gender-related Disparities in Clinical Characteristics and Outcomes in Heart Transplantation

PURPOSE OF REVIEW

Limited research has been conducted on sex disparities in heart transplant (HT). The aim of this review is to analyse the available evidence on the influence of sex and gender-related determinants in the entire HT process, as well as to identify areas for further investigation.

RECENT FINDINGS

Although women make up half of the population affected by heart failure and related mortality, they account for less than a third of HT recipients. Reasons for this inequality include differences in disease course, psychosocial factors, concerns about allosensitisation, and selection or referral bias in female patients. Women are more often listed for HT due to non-ischaemic cardiomyopathy and have a lower burden of cardiovascular risk factors. Although long-term prognosis appears to be similar for both sexes, there are significant disparities in post-HT morbidity and causes of mortality (noting a higher incidence of rejection in women and of malignancy and cardiac allograft vasculopathy in men). Additional research is required to gain a better understanding of the reasons behind gender disparities in eligibility and outcomes following HT. This would enable the fair allocation of resources and enhance patient care.

The IMPACT Score: Does Sex Matter?

OBJECTIVE

The Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score is a quantitative risk index that predicts 1-year mortality risk, derived from United Network for Organ Sharing data in which women are underrepresented. The validity of the IMPACT score in 1-year mortality risk after OHT in women is unknown. The objective of this study was to assess differences in score performance by sex. We hypothesized that the IMPACT score is a poor predictor of 1-year mortality risk after orthotopic heart transplantation (OHT) in women.

DESIGN

In this external validation study, demographic and clinical characteristics were compared by sex. The IMPACT score was calculated and regression models were constructed for the entire sample and stratified by sex. Model discrimination was assessed with the area under the receiver operating characteristic curve, and calibration was assessed graphically.

PARTICIPANTS

Patients 18 years and older who were first-time single OHT recipients from the International Society for Heart and Lung Transplantation registry from 2009 to 2018.

MEASUREMENTS AND MAIN RESULTS

For 1-year mortality, the area under the receiver operating characteristic curve (95% confidence interval) for the full sample was 0.59 (0.57-0.60): 0.58 (0.55-0.61) for women and 0.59 (0.58-0.61) for men. The 1-year mortality was 9.4% in the overall cohort, with no difference in mortality by sex (9.0% v 9.6% women v men, p = 0.22).

CONCLUSIONS

The IMPACT score exhibited poor discrimination and calibration in the International Society for Heart and Lung Transplantation 2009-2019 cohort, overall and by sex. There was no difference in 1-year mortality between women and men.

New Disease Trajectories of Heart Failure: Challenges in Determining the Ideal Timing of Palliative Care Implementation

Background: The disease trajectory of heart failure (HF), along with other organ failures, is still being elucidated. The trajectory is represented as a descending saw-tooth curve, indicating the frequent exacerbations and hospitalizations and slow progression to death. However, the clinical pattern of HF is no longer unique because of the definition of three distinct phenotypes, according to different values of ejection fraction (EF): HF with reduced EF (HFrEF), mildly reduced EF (HFmEF), and preserved EF (HFpEF). Patients with HFrEF have access to pharmacological and nonpharmacological treatments that have been shown to reduce mortality, unlike the other two classes for which no effective therapies are present. Therefore, their disease trajectories are markedly different. Methods: In this study, multiple new disease trajectories of HFrEF are being proposed, ranging from a complete and persistent recovery to rapid clinical deterioration and premature death. These new trajectories pose challenges to early implementation of palliative care (PC), as indicated in the guidelines. Results: From these considerations, we discuss how the improved prognosis of HFrEF because of effective treatment could paradoxically delay the initiation of early PC, especially with the insufficient palliative knowledge and training of cardiologists, who usually believe that PC is required only at the end of life. Conclusions: The novel therapeutic approaches for HF discussed in this study highlight the clinical specificity and peculiar needs of patients with HF. The changing model of disease trajectories of patients with HF will provide new opportunities for the early implementation of PC.

Differences in excess mortality by recipient sex after heart transplant: An individual patient data meta-analysis

BACKGROUND

Identification of differences in mortality risk between female and male heart transplant recipients may prompt sex-specific management strategies. Because worldwide, males of all ages have higher absolute mortality rates than females, we aimed to compare the excess risk of mortality (risk above the general population) in female vs male heart transplant recipients.

METHODS

We used relative survival models conducted separately in SRTR and CTS cohorts from 1988-2019, and subsequently combined using 2-stage individual patient data meta-analysis, to compare the excess risk of mortality in female vs male first heart transplant recipients, accounting for the modifying effects of donor sex and recipient current age.

RESULTS

We analyzed 108,918 patients. When the donor was male, female recipients 0-12 years (Relative excess risk (RER) 1.13, 95% CI 1.00-1.26), 13-44 years (RER 1.17, 95% CI 1.10-1.25), and ≥45 years (RER 1.14, 95% CI 1.02-1.27) showed higher excess mortality risks than male recipients of the same age. When the donor was female, only female recipients 13-44 years showed higher excess risks of mortality than males (RER 1.09, 95% CI 1.00-1.20), though not significantly (p = 0.05).

CONCLUSIONS

In the setting of a male donor, female recipients of all ages had significantly higher excess mortality than males. When the donor was female, female recipients of reproductive age had higher excess risks of mortality than male recipients of the same age, though this was not statistically significant. Further investigation is required to determine the reasons underlying these differences.

Innate Allorecognition in Transplantation: Ancient Mechanisms With Modern Impact

Through the effective targeting of the adaptive immune system, solid organ transplantation became a life-saving therapy for organ failure. However, beyond 1 y of transplantation, there is little improvement in transplant outcomes. The adaptive immune response requires the activation of the innate immune system. There are no modalities for the specific targeting of the innate immune system involvement in transplant rejection. However, the recent discovery of innate allorecognition and innate immune memory presents novel targets in transplantation that will increase our understanding of organ rejection and might aid in improving transplant outcomes. In this review, we look at the latest developments in the study of innate allorecognition and innate immune memory in transplantation.

Sex differences in heart transplantation - analysis of the national inpatient sample 2012-2019

INTRODUCTION

Advanced heart failure therapies and heart transplantation (HT) have been underutilized in women. Therefore, we aimed to explore the clinical characteristics and outcomes of HT by sex.

METHODS

We conducted a retrospective analysis of adult discharges from the National Inpatient Sample (NIS) between 2012 and 2019. International Classification of Disease (ICD) procedure codes were used to identify those who underwent HT.

RESULTS

A total of 20,180 HT hospitalizations were identified from 2012-2019. Among them, 28 % were female. Women undergoing HT were younger (mean age 51 vs. 54.5 years, p<0.001). HT hospitalizations among men were more likely to have atrial fibrillation, diabetes, hypertension, renal failure, dyslipidemia, smoking, and ischemic heart disease. HT hospitalizations among women were more likely to have hypothyroidism and valvular heart disease. HT hospitalizations in women were associated with no significant difference in risk of in-hospital mortality (adjusted odds ratio [OR] 0.82; 95 % confidence interval [CI] 0.58-1.16, p=0.271), no significant difference in length of stay or inflation-adjusted cost. Men were more likely to develop acute kidney injury during HT hospitalization (69.2 % vs. 59.7 %, adjusted OR 0.71, 95 % CI 0.61-0.83, p<0.001).

CONCLUSIONS

HT utilization is lower in women. However, most major in-hospital outcomes for HT are similar between the sexes. Further studies are need to explore the causes of lower rates of HT in women.

Artificial Intelligence Approaches for Predicting the Risks of Durable Mechanical Circulatory Support Therapy and Cardiac Transplantation

Background: The use of AI-driven technologies in probing big data to generate better risk prediction models has been an ongoing and expanding area of investigation. The AI-driven models may perform better as compared to linear models; however, more investigations are needed in this area to refine their predictability and applicability to the field of durable MCS and cardiac transplantation. Methods: A literature review was carried out using Google Scholar/PubMed from 2000 to 2023. Results: This review defines the knowledge gaps and describes different AI-driven approaches that may be used to further our understanding. Conclusions: The limitations of current models are due to missing data, data imbalances, and the uneven distribution of variables in the datasets from which the models are derived. There is an urgent need for predictive models that can integrate a large number of clinical variables from multicenter data to account for the variability in patient characteristics that influence patient selection, outcomes, and survival for both durable MCS and HT; this may be fulfilled by AI-driven risk prediction models.

Italian Association of Hospital Cardiologists Position Paper 'Gender discrepancy: time to implement gender-based clinical management'

It has been well assessed that women have been widely under-represented in cardiovascular clinical trials. Moreover, a significant discrepancy in pharmacological and interventional strategies has been reported. Therefore, poor outcomes and more significant mortality have been shown in many diseases. Pharmacokinetic and pharmacodynamic differences in drug metabolism have also been described so that effectiveness could be different according to sex. However, awareness about the gender gap remains too scarce. Consequently, gender-specific guidelines are lacking, and the need for a sex-specific approach has become more evident in the last few years. This paper aims to evaluate different therapeutic approaches to managing the most common women's diseases.

Relationship between donor ejection fraction, left ventricular wall thickness and mortality in heart transplants recipients

This study explored the impact of donor left ventricular ejection fraction (EF) and left ventricular wall thickness (LVWT) on mortality among heart transplant (HTx) recipients. Utilizing data from the United Network for Organ Sharing (UNOS) registry, adult HTx recipients between 2006-2022 were analyzed. Patients were categorized into four groups based on donor EF(>50 % or ≤50 %) and LVWT(<1.4 cm or ≥1.4 cm). 21,012 patients were included. There were significant differences in baseline characteristics among the groups. Unadjusted mortality was 6.3 %, 6.0 %, 6.0 %, and 2.4 %(p=0.86) at 30-days; 16.2 %, 13.5 %, 16.8 %, and 7.3 %(p=0.08) at 1-year; and 32.2 %, 29.2 %, 35.4 %, and 29.0 %(p=0.18) at 5-years, respectively. In addition, adjusted mortality did not differ across the groups. There were no significant differences in recipient mortality in groups based on donor EF and LVWT. Expanding the donor selection criteria would allow for increase in the donor pool and assist in decreasing the mortality, while on the waitlist for HTx.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Gender Effect on Clinical Profiles, Pharmacological Treatments and Prognosis in Patients Hospitalized for Heart Failure

Heart failure (HF) is a significant disease affecting 1-2% of the general population. Despite its general aspects, HF, like other cardiovascular diseases, presents various gender-specific aspects in terms of etiology, hemodynamics, clinical characteristics, therapy, and outcomes. As is well known, HF with preserved ejection fraction more frequently affects females, with diabetes and arterial hypertension representing the most critical determinants of HF. On the other hand, women are traditionally underrepresented in clinical trials and are often considered undertreated. However, it is not clear whether such differences reflect cultural behaviors and clinical inertia or if they indicate different clinical profiles and the impact of sex on hard clinical outcomes. We aimed to review the sex-related differences in patients affected by HF.

Comparing 3-year survival and readmissions between HeartMate 3 and heart transplant as primary treatment for advanced heart failure

OBJECTIVE

To compare 3-year survival and readmissions of patients who received the HeartMate 3 (HM3) left ventricular assist device (LVAD) or underwent orthotopic heart transplantation (OHT) as primary treatment for advanced heart failure.

METHODS

We retrospectively analyzed 381 adult patients who received an HM3 LVAD or were listed for OHT between January 2014 and March 2021 at our center. To minimize crossover bias, OHT recipients with a prior LVAD were excluded, and HM3 patients were censored at the time of transplant. Cohorts were propensity score-matched to reduce confounding variables. The primary outcome was 3-year survival, and the secondary outcome was mean cumulative all-cause unplanned readmission.

RESULTS

The study population comprised 185 HM3 patients (49%) and 196 OHT patients (51%), with 104 propensity score-matched patients in each group. After propensity score matching, there was no statistical difference in 3-year survival (83.7% for HM3 vs 87.0% for OHT; P = .91; relative risk [RR], 1.00; 95% confidence interval [CI], 0.45-2.20). In the unmatched cohorts, patients age 18 to 49 years had comparable survival with HM3 and OHT (96.9% vs 95.9%; N = 91; P = 1.00; RR, 0.92; 95% CI, 0.09-9.78). Patients age 50+ years had slightly inferior survival with HM3 (75.0% vs 83.9%; N = 290; P = .60; RR, 1.51; 95% CI, 0.85-2.68). The mean number of readmissions at 3 years was higher in the HM3 group (3.89 vs 2.05; P < .001).

CONCLUSIONS

This exploratory analysis suggests that for similar patients, HM3 may provide comparable 3-year survival to OHT as a primary treatment for heart failure but may result in more readmissions.

Impact of new allocation system on length of stay following heart transplantation in the United States

BACKGROUND

United Network for Organ Sharing (UNOS) allocation criteria changed in 2018 to accommodate the increased prevalence of ventricular assist device use as a bridge to heart transplant, which consequently prioritized sicker patients. We aimed to assess the impact of this new allocation policy on the length of stay following heart transplantation. Secondary outcomes include other risk factors for prolonged hospitalization and its effect on mortality and postoperative complications.

METHODS

The UNOS Registry was queried to identify patients who underwent isolated heart transplants in the United States between 2001 and 2023. Patients were divided into quartiles according to their respective length of stay.

RESULTS

A total of 57 020 patients were included, 15 357 of which were allocated with the new system. The median hospital length of stay was 15 days (mean 22.7 days). Length of stay was longer in the new allocation era (25 ± 30 vs. 22 ± 27 days, p < .001). The longer length of stay was associated with increased 5-year mortality in the new allocation system (aHR: 1.18; 95% CI: 1.15, 1.20; p-value: < .001).

CONCLUSION

Longer hospital stays and associated observed increased risk for mortality in the era after the allocation criteria change reflect the rationale of this shift which was to prioritize heart transplants for sicker patients. Further studies are needed to track the progress of surgical and perioperative management of these studies over time.

The Role of Palliative Care in Heart Failure, Part 2: Characteristics of Patients Undergoing Outpatient Palliative Care Evaluation for Advanced Cardiac Therapies

Background: Characteristics of patients undergoing outpatient evaluation for advanced cardiac therapies are largely unknown. Objective: To describe demographics, baseline quality of life, and frailty of patients undergoing evaluation for advanced therapies at the time of presentation for evaluation in an outpatient cardiac palliative care clinic and examine key quality of life differences across patients. Design: Retrospective chart review to report baseline demographics and quality of life. Settings/Subjects: Patients at a large academic medical center in the United States referred for advanced cardiac therapies in 2021. Measurements: Depression and anxiety were measured using the Hospital Anxiety and Depression Scale; quality of life was measured using the Functional Assessment of Chronic Illness Therapy-Palliative care (FACIT-Pal) tool; and frailty was measured using the Fried Frailty Phenotype. Differences in quality of life by disease etiology, demographic characteristics, and frailty were assessed. Results: Fifty-four patients were seen in the outpatient cardiac palliative care clinic for advanced therapy evaluation. Most were Caucasian (80%) and male (74%). Patients traveled an average of 61 minutes to the clinic. All but five lived in a rural, medically underserved, or health professional shortage area. Forty percent scored abnormal or borderline abnormal for anxiety; 22% scored abnormal or borderline abnormal for depression. The FACIT-Pal mean score was 129 (standard deviation 23), with emotional and functional well-being domains contributing most to poor quality of life. Seventy-one percent were frail. Patients with a nonischemic etiology had a 3.32 times higher rate of anxiety than nonischemic patients (95% confidence interval = 1.05-10.54, p = 0.041). Conclusion: As patients undergoing transplant evaluation have high levels of depression, anxiety, and frailty, interdisciplinary care teams will be needed to properly manage the needs of this complex population. These results can inform efforts to integrate palliative care into advanced cardiac therapy and improve patients' experiences.

Sex Differences in Cardiac Transplantation

PURPOSE OF REVIEW

The goal of this review was to summarize contemporary evidence surrounding sex differences in heart transplantation (HT).

RECENT FINDINGS

Women have steadily comprised approximately 25% of waitlist candidates and HT recipients. This disparity is likely multifactorial with possible explanations including barriers in referral to advanced heart failure providers, implicit bias, and concerns surrounding sensitization. Women continue to experience higher waitlist mortality at the highest priority tiers. After HT, there are differences in post-transplant complications and outcomes. Future areas of study should include sex differences in noninvasive surveillance, renal outcomes after transplantation, and patient-reported outcomes. There are important sex-specific considerations that impact candidate selection, donor matching, waitlist and post-transplant outcomes. Concerted efforts are needed to improve referral patterns to ensure transplantation is allocated equally.

Addressing Barriers for Women with Advanced Heart Failure

PURPOSE OF REVIEW

Describe disparities in diagnosis and management between men and women with advanced heart failure (HF). Our goal is to identify barriers and suggest solutions.

RECENT FINDINGS

Women with advanced HF are less likely to undergo diagnostic testing and procedures (i.e., revascularization, implantable cardioverter defibrillators, cardiac resynchronization therapy, mechanical circulatory support, and orthotopic heart transplantation). Disparities related to gender create less favorable outcomes for women with advanced HF. The issues arise from access to care, paucity of knowledge, enrollment in clinical trials, and eligibility for advanced therapies. In this review, we propose a call to action to level the playing field in order to improve survival in women with advanced HF.

Sex differences in clinical characteristics and outcomes in patients undergoing heart transplantation

AIMS

Whether sex affects selection for and outcomes after heart transplantation (HTx) remains unclear. We aimed to show sex differences in pre-transplant characteristics and outcomes after HTx.

METHODS AND RESULTS

From 1995 to 2019, 49 200 HTx recipients were prospectively enrolled in the Organ Procurement and Transplantation Network. Logistic regression models were used to evaluate clinical characteristics by sex. Multivariable Cox regression models were fitted to assess sex differences in all-cause mortality, cardiovascular mortality, graft failure, cardiac allograft vasculopathy (CAV), and malignancy. In 49 200 patients (median age 55 years, interquartile range 46-62; 24.6% women), 49 732 events occurred during a median follow-up of 8.1 years. Men were older than women, had more often ischaemic cardiomyopathy (odds ratio [OR] 3.26, 95% confidence interval [CI] 3.11-3.42; P < 0.001), and a higher burden of cardiovascular risk factors, whereas women had less malignancies (OR 0.47, CI 0.44-0.51; P < 0.001). Men were more often treated in intensive care unit (OR 1.24, CI 1.12-1.37; P < 0.001) with a higher need for ventilatory (OR 1.24, CI 1.17-1.32; P < 0.001) or VAD (OR 1.53, CI 1.45-1.63; P < 0.001) support. After multivariable adjustment, men had a higher risk for CAV (hazard ratio [HR] 1.21, CI 1.13-1.29; P < 0.001) and malignancy (HR 1.80, CI 1.62-2.00; P < 0.001). There were no differences in all-cause mortality, cardiovascular mortality, and graft failure between sexes.

CONCLUSIONS

In this US transplant registry, men and women differed in pre-transplant characteristics. Male sex was independently associated with incident CAV and malignancy even after multivariable adjustment. Our results underline the need for better personalized post-HTx management and care.

The effect of sex inequality on solid organ transplantation: A systematic review and meta-analysis

BACKGROUND

Sex disparities are related to biological differences, which may have significant impact on patient and allograft outcomes. The aim was to investigate the impact of sex on clinical and safety outcomes after solid organ transplantation (SOT).

METHODS

A systematic review and meta-analysis was performed. Observational studies comparing females vs. males after SOT were considered for inclusion after a systematic search of the Pubmed, Cochrane Library, and Web of Science databases conducted from 2016 to 2021. Primary outcome was mortality. PROSPERO register number: CRD42021282615.

RESULTS

After retrieving 1103 studies, 22 observational studies (1,045,380 subjects) were finally deemed eligible for inclusion. Females accounted 36.3% of SOT recipients, but presented significantly lower mortality (odds ratio (OR): 0.87, 95% confidence interval (CI): 0.83-0.92, I2=78%). In subgroup analyses, mortality was significantly lower in females undergoing liver (OR: 0.89 95%CI: 0.86-0.92, I2=0%) or kidney transplantation (OR: 0.82 95%CI: 0.76-0.89, I2=72%). Male sex was consistently reported as a protective factor against hospital readmission. Among the outcomes, allograft dysfunction was influenced by a combination of donor-recipient sex and age. Data on overall infections were inconclusive. Several reports suggest a higher risk of malignancy among males.

CONCLUSIONS

Females represent one-third of SOT recipients but have higher survival rates than males after liver and kidney transplantation. The impact on graft dysfunction was heterogeneous. While further research is warranted, our findings should encourage clinicians and researchers to consider sex as a factor when taking decisions regarding SOT management.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Metabolic reprogramming by immune-responsive gene 1 up-regulation improves donor heart preservation and function

Preservation quality of donor hearts is a key determinant of transplant success. Preservation duration beyond 4 hours is associated with primary graft dysfunction (PGD). Given transport time constraints, geographical limitations exist for donor-recipient matching, leading to donor heart underutilization. Here, we showed that metabolic reprogramming through up-regulation of the enzyme immune response gene 1 (IRG1) and its product itaconate improved heart function after prolonged preservation. Irg1 transcript induction was achieved by adding the histone deacetylase (HDAC) inhibitor valproic acid (VPA) to a histidine-tryptophan-ketoglutarate solution used for donor heart preservation. VPA increased acetylated H3K27 occupancy at the IRG1 enhancer and IRG1 transcript expression in human donor hearts. IRG1 converts aconitate to itaconate, which has both anti-inflammatory and antioxidant properties. Accordingly, our studies showed that Irg1 transcript up-regulation by VPA treatment increased nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) in mice, which was accompanied by increased antioxidant protein expression [hemeoxygenase 1 (HO1) and superoxide dismutase 1 (SOD1)]. Deletion of Irg1 in mice (Irg1^-/-) negated the antioxidant and cardioprotective effects of VPA. Consistent with itaconate's ability to inhibit succinate dehydrogenase, VPA treatment of human hearts increased itaconate availability and reduced succinate accumulation during preservation. VPA similarly increased IRG1 expression in pig donor hearts and improved its function in an ex vivo cardiac perfusion system both at the clinical 4-hour preservation threshold and at 10 hours. These results suggest that augmentation of cardioprotective immune-metabolomic pathways may be a promising therapeutic strategy for improving donor heart function in transplantation.

Female donor hearts can improve survival for male pediatric heart transplant recipients

BACKGROUND

Both gender- and weight-matching between donor and recipient are thought to impact survival in pediatric heart transplantation, with clinical dogma holding that male donor hearts and "ideal" weight-matching yield superior survival. The composite impacts of gender and weight on post-transplant survival (PTS) are understudied.

METHODS

All pediatric (age <18) heart recipients between 1989 and 2021 with the complete recipient and donor gender and weight data were identified in the United Network for Organ Sharing database. Patients were grouped by recipient-donor gender (M & F) and donor-to-recipient weight ratio (DRWR; undersized [<0.8], ideal-sized [0.8-1.5], oversized [>1.5]).

RESULTS

A total of 10 697 patients were identified. Among male recipients, PTS was greatest with oversized DRWR from either male or female donors (median 22.4 and 20.6 years; p < .001 vs. others) and lowest for undersized DRWR from either male or female donors (median 13.4 and 13.2 years; p < .001 vs. others). The majority (64%) of male recipients received ideal-sized DRWR, among which female donor hearts yielded superior survival to males (median 18.9 vs. 17.4 years, p = .014). No differences in PTS existed for female recipients on the basis of gender-match, DRWR, and gender/DRWR together (all p > .1).

CONCLUSIONS

When considered together, gender and DRWR pairings impact PTS in male-but not female-pediatric heart transplant recipients. For males receiving ideal-sized DRWR organs (most common pairing, >60%), male recipients achieve superior survival when female donor hearts are transplanted. These findings suggest that if weight is being used for size-matching, donor gender should also be considered, particularly for male recipients.

Donor specific antibodies association with survival and adverse events after heart transplantation: A single center retrospective study between 2006 and 2021

OBJECTIVE

Newly detected donor HLA-specific antibodies (DSA) are historically known to be associated with reduced survival in heart transplant patients. Our objective is to clarify the modern incidence of DSA and determine its relationship with survival and MACE.

METHODS

This retrospective study included all patients undergoing orthotopic heart transplantation at Harefield Hospital, London between January 1, 2006 and May 31, 2021. We identified patients who developed DSA at any point post heart transplantation and its effect on survival and MACE (defined as rejection, coronary event, stroke, and arrhythmia.

RESULTS

In total of 232 patients were included with a median follow up time of 4.7 years post heart transplantation. 23.7% of patients included developed DSA post heart transplantation. There was a significantly increased risk of death in patients developing DSA versus not (sub distribution hazard ratio [SHR] 1.83, 95% confidence interval 1.03-3.24, p = .04). At the time of detection of DSA, 38.2% of the cohort had rejection necessitating treatment. A MACE event had occurred in 48.1% by 2 years and 53.7% by 3 years in the DSA cohort. There was a significantly increased risk of MACE in patients developing DSA versus not (SHR 2.48 [1.58-3.89, p < .0001]).

CONCLUSIONS

This study showed an increased risk of death and MACE in patients developing DSA post heart transplantation. Further research is required into the optimal management of these patients.

Influence of sex on global myocardial ischemia tolerance and mitochondrial function in circulatory death donor hearts

Donation after circulatory death (DCD) donor hearts are not routinely used for heart transplantation (HTx) because of ischemic damage, which is inherent to the DCD process. HTx outcomes are suboptimal in males who received female donor hearts. The exact mechanism for suboptimal outcomes from female donor hearts has not been defined. Differential susceptibility to ischemia tolerance, which would play a significant role in DCD donation, could be a reason but has not been studied. We studied the influence of sex on global myocardial ischemia tolerance and mitochondrial function. Sprague-Dawley rats of both sexes were assigned to DCD (n = 32) or control beating-heart donor (CBD, n = 28) groups. DCD hearts underwent 25 min of in vivo global myocardial ischemia and 90 min of ex vivo Krebs-Henseleit buffer perfusion at 37°C. CBD hearts were procured without ischemia. Infarct size was determined in hearts following 90 min of reperfusion, and in another set of hearts, mitochondrial function (oxidative-phosphorylation) was studied following 60 min of reperfusion. Infarct size was increased 3.3-fold in male and 3.1-fold in female DCD hearts compared with CBD hearts. However, infarct size (%) was comparable in female and male DCD hearts (male: 25.4 ± 3.7 vs. female 19.0 ± 3.3, P = NS). Oxidative phosphorylation was similarly decreased in male and female DCD hearts' mitochondria compared with CBD hearts' mitochondria. Thus, neither infarct size nor mitochondrial dysfunction was higher in female DCD hearts. These results suggest that the susceptibility to ischemia is not the reason for suboptimal HTx outcomes with female donor hearts.NEW & NOTEWORTHY The current study shows cardiac injury is not increased in female DCD hearts following global ischemia-reperfusion compared with male DCD hearts. In addition, mitochondrial dysfunction with DCD ischemia-reperfusion is comparable in both sexes. Sex-specific immune responses and hormone receptor modulation may contribute to suboptimal outcomes in male HTx recipients with female donor hearts.

Direct reprogramming of cardiomyocytes into cardiac Purkinje-like cells

Currently, there are no treatments that ameliorate cardiac cell death, the underlying basis of cardiovascular disease. An unexplored cell type in cardiac regeneration is cardiac Purkinje cells; specialized cells from the cardiac conduction system (CCS) responsible for propagating electrical signals. Purkinje cells have tremendous potential as a regenerative treatment because they may intrinsically integrate with the CCS of a recipient myocardium, resulting in more efficient electrical conduction in diseased hearts. This study is the first to demonstrate an effective protocol for the direct reprogramming of human cardiomyocytes into cardiac Purkinje-like cells using small molecules. The cells generated were genetically and functionally similar to native cardiac Purkinje cells, where expression of key cardiac Purkinje genes such as CNTN2, ETV1, PCP4, IRX3, SCN5a, HCN2 and the conduction of electrical signals with increased velocity was observed. This study may help to advance the quest to finding an optimized cell therapy for heart regeneration.

Sex differences in patients undergoing heart transplantation and LVAD therapy

INTRODUCTION

Left ventricular assist device (LVAD) and heart transplantation (HT) are the two life-sustaining therapies that have revolutionized the management of end-stage heart failure (HF). Yet, significant sex differences exist with respect to their use and effects.

AREAS COVERED

This review summarizes sex differences in the utilization, outcomes, and complications of LVAD and HT. Particular emphasis is placed on leading clinical trials in the field, historical and recent large registries-based analyses, as well as contemporary technological and policy changes affecting these differences.

EXPERT OPINION

Women with advanced HF remain under-treated with guideline-directed medical therapy and are less likely to be referred for consideration for LVAD and HT. This remains true despite newer LVAD technology and the new heart transplant allocation system. Community outreach, education, as well as increased representation of women in clinical research may reduce inequities.

Regulatory and transitional B cells: potential biomarkers and therapeutic targets in organ transplantation

PURPOSE OF THE REVIEW

Regulatory B cells (Bregs) play a prominent role in various disease settings. While progress has been hindered by the lack of a specific Breg marker, new findings highlight their role modulating the alloimmune response and promoting allograft survival.

RECENT FINDINGS

Herein, we focus on the recent advances in Breg biology and their role in transplantation. We review studies showing that T-cell immunoglobulin and mucin domain 1 (TIM-1) is an inclusive and functional Breg marker in mice that may have human relevance. We highlight the utility of the B cell interleukin-10/tumor necrosis factor-alpha (IL-10/TNFα) ratio in identifying underlying immunological reactivity and predicting clinical outcomes in kidney transplantation. This may identify patients requiring more immunosuppression and provide insight into potential therapeutic approaches that can modulate the Breg: B effector cell (Beff) balance.

SUMMARY

Emerging data support Bregs as potent modulators of immune responses in humans. Their ability to promote allograft survival must await development of approaches to expand Bregs in vitro/in vivo . The low IL-10/TNFα ratio reflecting decreased Breg/Beff balance, predicts acute rejection (AR) and poorer outcomes in renal transplantation. It remains to be determined whether this paradigm can be extended to other allografts and whether therapy aiming to correct the relative deficiency of Bregs will improve outcomes.

Donor Macrophages Modulate Rejection After Heart Transplantation

BACKGROUND

Cellular rejection after heart transplantation imparts significant morbidity and mortality. Current immunosuppressive strategies are imperfect, target recipient T cells, and have adverse effects. The innate immune response plays an essential role in the recruitment and activation of T cells. Targeting the donor innate immune response would represent the earliest interventional opportunity within the immune response cascade. There is limited knowledge about donor immune cell types and functions in the setting of cardiac transplantation, and no current therapeutics exist for targeting these cell populations.

METHODS

Using genetic lineage tracing, cell ablation, and conditional gene deletion, we examined donor mononuclear phagocyte diversity and macrophage function during acute cellular rejection of transplanted hearts in mice. We performed single-cell RNA sequencing on donor and recipient macrophages and monocytes at multiple time points after transplantation. On the basis of our imaging and single-cell RNA sequencing data, we evaluated the functional relevance of donor CCR2+ (C-C chemokine receptor 2) and CCR2- macrophages using selective cell ablation strategies in donor grafts before transplant. Last, we performed functional validation that donor macrophages signal through MYD88 (myeloid differentiation primary response protein 88) to facilitate cellular rejection.

RESULTS

Donor macrophages persisted in the rejecting transplanted heart and coexisted with recipient monocyte-derived macrophages. Single-cell RNA sequencing identified donor CCR2+ and CCR2- macrophage populations and revealed remarkable diversity among recipient monocytes, macrophages, and dendritic cells. Temporal analysis demonstrated that donor CCR2+ and CCR2- macrophages were transcriptionally distinct, underwent significant morphologic changes, and displayed unique activation signatures after transplantation. Although selective depletion of donor CCR2- macrophages reduced allograft survival, depletion of donor CCR2+ macrophages prolonged allograft survival. Pathway analysis revealed that donor CCR2+ macrophages are activated through MYD88/nuclear factor kappa light chain enhancer of activated B cells signaling. Deletion of MYD88 in donor macrophages resulted in reduced antigen-presenting cell recruitment, reduced ability of antigen-presenting cells to present antigen to T cells, decreased emergence of allograft-reactive T cells, and extended allograft survival.

CONCLUSIONS

Distinct populations of donor and recipient macrophages coexist within the transplanted heart. Donor CCR2+ macrophages are key mediators of allograft rejection, and deletion of MYD88 signaling in donor macrophages is sufficient to suppress rejection and extend allograft survival. This highlights the therapeutic potential of donor heart-based interventions.

Disparities in heart transplantation

PURPOSE OF REVIEW

Heart transplantation remains the gold standard therapy for end stage heart failure, but barriers remain, preventing equitable access to and affecting outcomes following transplantation. The objective of this review is to summarize current and historical literature on the disparities that persist, and to highlight the gaps in evidence for further investigation.

RECENT FINDINGS

Although progress has been made to increase the rates of advanced heart failure therapies to racial/ethnic minority populations and those with lower socioeconomic status, differential access and outcomes remain. The disparities that persist are categorized by patient demographics, social influences, geopolitical factors, and provider bias.

SUMMARY

Disparities in heart transplantation exist, which span a wide spectrum. Healthcare professionals need to be cognizant of these disparities that patients face in terms of access to and outcomes for heart transplantation. Further research and system changes are needed to make heart transplantation a fairer option for patients of varying backgrounds with end stage heart failure.

Long-term Survival Following Heart Transplantation for Chagas Versus Non-Chagas Cardiomyopathy: A Single-center Experience in Northeastern Brazil Over 2 Decades

Data on post–heart transplant (HT) survival of patients with Chagas cardiomyopathy (CC) are scarce. We sought to evaluate post-HT survival in patients with CC as compared with other causes of heart failure across different eras of HT.

Increased Opportunities for Transplantation for Women in the New Heart Allocation System

BACKGROUND

Historically, women have had less access to advanced heart failure therapies, including temporary and permanent mechanical circulatory support and heart transplantation (HT), with worse waitlist and post-transplant survival compared with men. This study evaluated for improvement in sex differences across all phases of HT in the 2018 allocation system.

METHODS AND RESULTS

The United Network for Organ Sharing registry was queried to identify adult patients (≥18 years) listed for HT from October 18, 2016, to October 17, 2018 (old allocation), and from October 18, 2018, to October 18, 2020 (new allocation). The outcomes of interest included waitlist survival, pretransplant use of temporary and durable mechanical circulatory support, rates of HT, and post-transplant survival. There were 15,629 patients who were listed for HT and included in this analysis; 7745 (2039 women, 26.3%) in the new and 7875 patients (2074 women, 26.3%) in the old allocation system. When compared with men in the new allocation system, women were more likely to have lower priority United Network for Organ Sharing status at time of transplant, and less likely to be supported by an intra-aortic balloon pump (27.1% vs 32.2%, P < .001), with no difference in the use of venoarterial extracorporeal membrane oxygenation (5.5% vs 6.3%, P = .28). Despite these findings, when transplantation was viewed in the context of risk for death or delisting, the cumulative incidence of transplant within 6 months of listing was higher in women than men in the new allocation system (62.4% vs 54.9%, P < .001) with no differences in post-transplant survival. When comparing women in the old with the new allocation system, the distance traveled for organ procurement was 187.5 ± 207.0 miles vs 272.8 ± 233.7 miles (P < .001).

CONCLUSIONS

Although the use of temporary mechanical circulatory support in women remains lower than in men in the new allocation system, more women are being transplanted with comparable waitlist and post-transplant outcomes as men. Broader sharing may be making its greatest impact on improving transplant opportunities for women.

Emergency department use and hospital admissions among adult orthotopic heart transplant patients

Objective

To study the demographics, clinical presentations, and outcomes of emergency department (ED) visits of patients with heart transplantation (HT) in the United States.

Methods

We performed a secondary analysis of the National Emergency Department Sample database from 2016 to 2018. All ED visits of patients with HT aged ≥ 18 years were identified using International Classification of Diseases, Tenth Revision codes.

Results

Out of a total 308,182,495 national ED visits, 55,583 were HT‐related visits. The median age was 61.07 years (interquartile range [IQR]: 46.91–69.38) and 69.44% were males. The hospital admission rate was 54.3% and median inpatient length of stay was 3.19 days (IQR: 1.63–5.92). The mortality rate during inpatient stay was 1.16%. Median inpatient and ED charges among admitted patients were $37,911 (IQR: $21,487–$71,262). The most common primary diagnosis of HT‐related ED visits was sepsis (4.3%) followed by acute kidney injury (3.57%) and chest pain (3%).

Conclusion

More than half of total ED visits among HT patients resulted in hospital admission. The most common cause for ED visit in these patients was sepsis followed by acute kidney injury and chest pain.

Early and Midterm Results of Orthotopic Heart Transplantation in Poland (2015-2019)

Orthotopic heart transplantation (OHT) has become one of the most expensive and resource-consuming treatment options for patients with end-stage heart failure. It is therefore useful to review clinical data, such as treatment duration after surgery and midterm follow-up in this group of patients. Contemporary epidemiologic data on early and midterm OHT follow-ups including patient demographics, hospitalization rates and related post-OHT morbidity, and mortality are scarce in Poland. The aim of the study was to determine early survival, hospitalization rates related to OHT and related morbidity, and mortality in Poland in the recent decade.

High-Intensity Interval Training Among Heart Failure Patients and Heart Transplant Recipients: A Systematic Review

High-intensity interval training (HIIT), an exercise training modality of cardiac rehabilitation, has shown growing evidence of improving cardiovascular patients' prognosis and health outcomes. This study aimed to identify and summarize the effects of HIIT in heart failure (HF) patients, heart transplantation (HTx) recipients, and HF patients before and after HTx. This systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. For the past five years, a systematic search was done using PubMed, PubMed Central, Cochrane, Google Scholar, and ScienceDirect databases on September 15, 2021. Studies were selected based on the following predefined eligibility criteria: English-language randomized controlled trials (RCTs), observational studies, systematic reviews, and meta-analyses, which included HF patients and HTx patients, and assessment of effects HIIT. The relevant data were extracted to a predefined template. Consequently, quality assessment was done using each study's most commonly used assessment tools. The initial search generated 551 studies. Nine studies were included in the final selection - four RCTs, one cohort, one quasi-experimental study, two systematic reviews with meta-analyses, and one narrative review. HIIT was found to be generally superior or similar with other exercise training on VO2 peak, heart rate, LVEF, cardiac biomarkers, vascular function, blood pressure, body composition, and adverse events in HF patients and the aforementioned with QoL among HTx recipients. Data on cardiac remodeling and QoL of HF patients were inconclusive.

Cardiac allograft vasculopathy: current review and future research directions

Cardiac allograft vasculopathy (CAV) is a pathologic immune-mediated remodelling of the vasculature in transplanted hearts and, by impairing perfusion, is the major cause of late graft loss. Although best understood following cardiac transplantation, similar forms of allograft vasculopathy occur in other vascularized organ grafts and some features of CAV may be shared with other immune-mediated vasculopathies. Here, we describe the incidence and diagnosis, the nature of the vascular remodelling, immune and non-immune contributions to pathogenesis, current therapies, and future areas of research in CAV.

Infective endocarditis following heart transplantation: A systematic review

PURPOSE

Infective endocarditis (IE) is a rare but potentially fatal complication following heart transplantation (HTx). There is a lack of literature regarding the patterns and clinical course of IE development following HTx. We sought to pool the existing data in regards to defining characteristics, management options, and outcomes of IE following HTx.

METHODS

An electronic search of Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Ovid Medline, and the Scopus databases were performed to identify all articles in the English literature that report IE following HTx in adult patients. Patient-level data were extracted and analyzed.

RESULTS

Systematic search yielded 57 patients from 32 articles. Median patient age was 52 [IQR 43, 59] and 75% of patients (43/57) were male. Median time to IE presentation post-HTx was 8.4 [IQR 3.0, 35.8] months. IE of the mitral valve was observed in 36.8% (21/57) of patients, followed by mural IE in 24.6% (14/57), and tricuspid valve IE in 21.1% (12/57). The most common organisms were Staphylococcus aureus in 26.3% (15/57), Aspergillus fumigatus in 19.3% (11/57), Enterococcus faecalis in 12.3% (7/57), and an undetermined or unspecified organism in 14.0% (8/57) patients. Overall case fatality was 44.6% (25/56). Fungal IE was associated with a significantly higher case fatality 75.0% (9/12) than that of bacterial IE 36.1% (13/36) (p = 0.02). Surgical management of post-HTx IE was observed in 35.1% (20/57) of patients. This included valve surgery for 70.0% (14/20), including the mitral valve in 50.0% (7/14), aortic valve in 35.7% (5/14), and the tricuspid valve in 14.3% (2/14) of patients.

CONCLUSION

In addition to bacterial organisms, fungi also represent a frequent cause of IE in post-HTx patients. Overall HTx patient survival in the setting of IE is poor and may be worse if caused by A. fumigatus.

Sex Differences in Heart Failure

Heart failure (HF) continues to be a major contributor of morbidity and mortality for men and women alike, yet how the predisposition for, course and management of HF differ between men and women remains underexplored. Sex differences in traditional risk factors as well as sex-specific risk factors influence the prevalence and manifestation of HF in unique ways. The pathophysiology of HF differs between men and women and may explain sex-specific differences in clinical presentation and diagnosis. This in turn contributes to variation in response to both pharmacologic and device/surgical therapy. This review examines sex-specific differences in HF spanning prevalence, risk factors, pathophysiology, presentation, and therapies with a specific focus on highlighting gaps in knowledge with calls to action for future research efforts.

Extrinsically Conductive Nanomaterials for Cardiac Tissue Engineering Applications

Myocardial infarction (MI) is the consequence of coronary artery thrombosis resulting in ischemia and necrosis of the myocardium. As a result, billions of contractile cardiomyocytes are lost with poor innate regeneration capability. This degenerated tissue is replaced by collagen-rich fibrotic scar tissue as the usual body response to quickly repair the injury. The non-conductive nature of this tissue results in arrhythmias and asynchronous beating leading to total heart failure in the long run due to ventricular remodelling. Traditional pharmacological and assistive device approaches have failed to meet the utmost need for tissue regeneration to repair MI injuries. Engineered heart tissues (EHTs) seem promising alternatives, but their non-conductive nature could not resolve problems such as arrhythmias and asynchronous beating for long term in-vivo applications. The ability of nanotechnology to mimic the nano-bioarchitecture of the extracellular matrix and the potential of cardiac tissue engineering to engineer heart-like tissues makes it a unique combination to develop conductive constructs. Biomaterials blended with conductive nanomaterials could yield conductive constructs (referred to as extrinsically conductive). These cell-laden conductive constructs can alleviate cardiac functions when implanted in-vivo. A succinct review of the most promising applications of nanomaterials in cardiac tissue engineering to repair MI injuries is presented with a focus on extrinsically conductive nanomaterials.

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 Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights from 2020

THIS SPECIAL article is the 13th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr Kaplan, and the editorial board for the opportunity to continue this series; namely, the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology.1 The major themes selected for 2020 are outlined in this introduction, and each highlight is reviewed in detail in the main body of the article. The literature highlights in the specialty for 2020 begin with an update on valvular disease, with a focus on updates in management of aortic and mitral valve disorders. The second major theme is an update on coronary artery disease, with discussion of both medical and surgical management. The third major theme is focused on the perioperative management of patients with coronavirus disease 2019 (COVID-19), with the authors highlighting literature discussing medical, surgical, and anesthetic considerations for their cardiac care. The fourth major theme is an update in heart failure, with discussion of medical, psychosocial, and procedural aspects of this complicated disease process. The fifth and final theme focuses on the latest analyses regarding survival in heart transplantation. The themes selected for this 13th special article are only a few of the diverse advances in the specialty during 2020. These highlights will inform the reader of key updates on a variety of topics, leading to improvement of perioperative outcomes for patients with cardiothoracic and vascular disease.

Influence of Gender in Advanced Heart Failure Therapies and Outcome Following Transplantation

Biological differences between males and females change the course of different diseases and affect therapeutic measures' responses. Heart failure is not an exception to these differences. Women account for a minority of patients on the waiting list for heart transplantation or other advanced heart failure therapies. The reason for this under-representation is unknown. Men have a worse cardiovascular risk profile and suffer more often from ischemic heart disease. Conversely, transplanted women are younger and more frequently have non-ischemic cardiac disorders. Women's poorer survival on the waiting list for heart transplantation has been previously described, but this trend has been corrected in recent years. The use of ventricular assist devices in women is progressively increasing, with comparable results than in men. The indication rate for a heart transplant in women (number of women on the waiting list for millions of habitants) has remained unchanged over the past 25 years. Long-term results of heart transplants are equal for both men and women. We have analyzed the data of a national registry of heart transplant patients to look for possible future directions for a more in-depth study of sex differences in this area. We have analyzed 1-year outcomes of heart transplant recipients. We found similar results in men and women and no sex-related interactions with any of the factors related to survival or differences in death causes between men and women. We should keep trying to approach sex differences in prospective studies to confirm if they deserve a different approach, which is not supported by current evidence.

Twenty-year survival following orthotopic heart transplantation in the United States

BACKGROUND

This study evaluated 20-year survival after adult orthotopic heart transplantation (OHT).

METHODS

The United Network of Organ Sharing Registry database was queried to study adult OHT recipients between 1987 and 1998 with over 20-year posttransplant follow-up. The primary and secondary outcomes were 20-year survival and cause of death after OHT, respectively. Multivariable logistic regression was used to identify significant independent predictors of long-term survival, and long-term survival was compared among cohorts stratified by number of predictors using Kaplan Meier survival analysis.

RESULTS

20,658 patients undergoing OHT were included, with a median follow-up of 9.0 (IQR, 3.2-15.4) years. Kaplan-Meier estimates of 10-, 15-, and 20-year survival were 50.2%, 30.1%, and 17.2%, respectively. Median survival was 10.1 (IQR, 3.9-16.9) years. Increasing recipient age (>65 years), increasing donor age (>40 years), increasing recipient body mass index (>30), black race, ischemic cardiomyopathy, and longer cold ischemic time (>4 h) were adversely associated with a 20-year survival. Of these 6 negative predictors, presence of 0 risk factors had the greatest 10-year (59.7%) and 20-year survival (26.2%), with decreasing survival with additional negative predictors. The most common cause of death in 20-year survivors was renal, liver, and/or multisystem organ failure whereas graft failure more greatly impacted earlier mortality.

CONCLUSIONS

This study identifies six negative preoperative predictors of 20-year survival with 20-year survival rates exceeding 25% in the absence of these factors. These data highlight the potential for very long-term survival after OHT in patients with end-stage heart failure and may be useful for patient selection and prognostication.

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).