Clinical and gender differences in heart transplant recipients in the NEW HEART study

"My feelings and my thoughts are my lived experience, not the numbers they show me on a piece of paper": Indigenous experiences of liver transplantation in British Columbia, Canada

Indigenous Peoples in Canada face healthcare inequities impacting access to solid organ transplantation. The experiences of Indigenous patients during the liver transplant process, and how transplant professionals perceive challenges faced by Indigenous Peoples, has not been studied. Thirteen semi-structured qualitative interviews were conducted via telehealth with Indigenous liver transplant patients (n = 7) and transplant care providers (n = 6) across British Columbia, Canada between April 2021-May 2022. Themes were identified to inform clinical approaches and transplant care planning and validated by Indigenous health experts. Among patient participants: transplants occurred between 1992-2020; all were women; and the mean age at the time of interview was 60 years. Among transplant care provider participants: roles included nursing, social work, and surgery; 83% were women; and the median number of years in transplant care was ten. Three broad themes were identified: Indigenous strengths and resources, systemic and structural barriers, and inconsistent care and cultural safety across health professions impact Indigenous patient care during liver transplantation. This study contributes insights into systemic barriers and Indigenous resilience in the liver transplant journey. Dismantling structural barriers to early linkage to care is needed, and training for transplant clinicians on Indigenous histories, cultural protocols, and cultural safety is strongly recommended.

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.

Sex-specific patterns of donor-derived cell-free DNA in heart transplant rejection: An analysis from the Genomic Research Alliance for Transplantation (GRAfT)

BACKGROUND

Noninvasive methods for surveillance of acute rejection are increasingly used in heart transplantation (HT), including donor-derived cell-free DNA (dd-cfDNA). As other cardiac biomarkers differ by sex, we hypothesized that there may be sex-specific differences in the performance of dd-cfDNA for the detection of acute rejection. The purpose of the current study was to examine patterns of dd-cfDNA seen in quiescence and acute rejection in male and female transplant recipients.

METHODS

Patients enrolled in the Genomic Research Alliance for Transplantation who were ≥18 years at the time of HT were included. Rejection was defined by endomyocardial biopsy with acute cellular rejection (ACR) grade ≥2R and/or antibody-mediated rejection ≥ pAMR 1. dd-cfDNA was quantitated using shotgun sequencing. Median dd-cfDNA levels were compared between sexes during quiescence and rejection. The performance of dd-cfDNA by sex was assessed using area under the receiver operator characteristic (AUROC) curve. Allograft injury was defined as dd-cfDNA ≥0.25%.

RESULTS

One hundred fifty-one unique patients (49 female, 32%) were included in the analysis with 1,119 available dd-cfDNA measurements. Baseline characteristics including demographics and comorbidities were not significantly different between sexes. During quiescence, there were no significant sex differences in median dd-cfDNA level (0.04% [IQR 0.00, 0.16] in females vs 0.03% [IQR 0.00, 0.12] in males, p = 0.22). There were no significant sex differences in median dd-cfDNA for ACR (0.33% [0.21, 0.36] in females vs 0.32% [0.21, 1.10] in males, p = 0.57). Overall, median dd-cfDNA levels were higher in antibody-mediated rejection (AMR) than ACR but did not significantly differ by sex (0.50% [IQR 0.18, 0.82] in females vs 0.63% [IQR 0.32, 1.95] in males, p = 0.51). Elevated dd-cfDNA detected ACR/AMR with an AUROC of 0.83 in females and 0.89 in males, p-value for comparison = 0.16.

CONCLUSIONS

There were no significant sex differences in dd-cfDNA levels during quiescence and rejection. Performance characteristics were similar, suggesting similar diagnostic thresholds can be used in men and women for rejection surveillance.

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.

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.

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.

Cardiomyopathies in Women

Heart failure affects over 2.6 million people in the United States. While women have better overall survival rates, they also suffer from higher morbidity as shown by higher rates of hospitalization and worse quality of life. Several anatomical differences in women's hearts affect both systolic and diastolic cardiac physiology. Despite these findings, women are significantly underrepresented in clinical trials, necessitating extrapolation of data from males. Because women have sex-specific etiologies of heart failure and unique manifestations in genetic-related cardiomyopathies, meaningful sex-related differences affect heart failure outcomes as well as access to and outcomes in advanced heart failure therapies in women. This review explores these gender-specific differences and potential solutions to balance care between women and men.

Mechanisms and consequences of sex differences in immune responses

Biological sex differences refer to differences between males and females caused by the sex chromosome complement (that is, XY or XX), reproductive tissues (that is, the presence of testes or ovaries), and concentrations of sex steroids (that is, testosterone or oestrogens and progesterone). Although these sex differences are binary for most human individuals and mice, transgender individuals receiving hormone therapy, individuals with genetic syndromes (for example, Klinefelter and Turner syndromes) and people with disorders of sexual development reflect the diversity in sex-based biology. The broad distribution of sex steroid hormone receptors across diverse cell types and the differential expression of X-linked and autosomal genes means that sex is a biological variable that can affect the function of all physiological systems, including the immune system. Sex differences in immune cell function and immune responses to foreign and self antigens affect the development and outcome of diverse diseases and immune responses.

Rejection Requiring Treatment within the First Year following Heart Transplantation: The UNOS Insight

(1) Background: Heart failure is an extremely impactful health issue from both a social and quality-of-life point of view and the rate of patients with this condition is destined to rise in the next few years. Transplantation remains the mainstay of treatment for end-stage heart failure, but a shortage of organs represents a significant problem that prolongs time spent on the waiting list. In view of this, the selection of donor and recipient must be extremely meticulous, considering all factors that could predispose to organ failure. One of the main considerations regarding heart transplants is the risk of graft rejection and the need for immunosuppression therapy to mitigate that risk. In this study, we aimed to assess the characteristics of patients who need immunosuppression treatment for rejection within one year of heart transplantation and its impact on mid-term and long-term mortality. (2) Methods: The United Network for Organ Sharing (UNOS) Registry was queried to identify patients who solely underwent a heart transplant in the US between 2000 and 2021. Patients were divided into two groups according to the need for anti-rejection treatment within one year of heart transplantation. Patients' characteristics in the two groups were assessed, and 1 year and 10 year mortality rates were compared. (3) Results: A total of 43,763 patients underwent isolated heart transplantation in the study period, and 9946 (22.7%) needed anti-rejection treatment in the first year. Patients who required treatment for rejection within one year after transplant were more frequently younger (49 ± 14 vs. 52 ± 14 years, p < 0.001), women (31% vs. 23%, p < 0.001), and had a higher CPRA value (14 ± 26 vs. 11 ± 23, p < 0.001). Also, the rate of prior cardiac surgery was more than double in this group (27% vs. 12%, p < 0.001), while prior LVAD (12% vs. 11%, p < 0.001) and IABP (10% vs. 9%, p < 0.01) were more frequent in patients who did not receive anti-rejection treatment in the first year. Finally, pre-transplantation creatinine was significantly higher in patients who did not need treatment for rejection in the first year (1.4 vs. 1.3, p < 0.01). Most patients who did not require anti-rejection treatment underwent heart transplantation during the new allocation era, while less than half of the patients who required treatment underwent transplantation after the new allocation policy implementation (65% vs. 49%, p < 0.001). Patients who needed rejection treatment in the first year had a higher risk of unadjusted 1 year (HR: 2.25; 95% CI: 1.88-2.70; p < 0.001), 5 year (HR: 1.69; 95% CI: 1.60-1.79; p < 0.001), and 10 year (HR: 1.47; 95% CI: 1.41-1.54, p < 0.001) mortality, and this was confirmed at the adjusted analysis at all three time-points. (4) Conclusions: Medical treatment of acute rejection was associated with significantly increased 1 year mortality compared to patients who did not require anti-rejection therapy. The higher risk of mortality was confirmed at a 10 year follow-up. Further studies and newer follow-up data are required to investigate the role of anti-rejection therapy in the heart transplant population.

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.

Understanding and Investigating Sex-Based Differences in Heart Transplantation: A Call to Action

Women represent only about 25% of heart transplant recipients annually. Although the number of women living with advanced heart failure remains unknown, epidemiologic research suggests that more women should be receiving advanced heart failure therapies. Sex differences in risk factors, presentation, response to pharmacotherapy, and outcomes in heart failure have been well described. Yet, less is known about sex differences in heart transplant candidate selection, waitlist management, donor selection, perioperative considerations, and post-transplant management and outcomes. The purpose of this review was to summarize the existing published reports related to sex differences in heart transplantation, highlighting areas in which sex-based considerations are well described and supported by available evidence, and emphasizing topics that require further study.

Sex differences in patterns of referral and resource utilization in the cardiology clinic: an outpatient analysis

Aims

Women may have different management patterns than men in specialised care. Our aim was to assess potential sex differences in referral, management and outcomes of patients attending outpatient cardiac consultations.

Methods and results

Retrospective observational analysis of patients ≥18 years referred for the first time from primary care to a tertiary hospital cardiology clinic in 2017-2018, comparing reasons for referral, decisions and post-visit outcomes by sex.A total of 5,974 patients, 2,452 (41.0%) men aged 59.2 ± 18.6 years and 3,522 (59.0%) women aged 64.5 ± 17.9 years (P < 0.001) were referred for a first cardiology consultation. The age-related referral rates were higher in women. The most common reasons for consultation were palpitations in women (n = 676; 19.2%) and ECG abnormalities in men (n = 570; 23.2%). Delays to cardiology visits and additional tests were similar. During 24 months of follow-up, women had fewer cardiology hospitalisations (204; 5.8% vs. 229; 9.3%; P = 0.003) and lower mortality (65; 1.8% vs. 66; 2.7%; P = 0.028), but those aged <65 years had more emergency department visits (756; 48.5% vs. 560; 39.9%, P < 0.001) than men.

Conclusion

There are substantial sex differences in primary care cardiology referral patterns, including causes, rates, decisions and outcomes, which are only partially explained by age differences. Further research is needed to understand the reasons for these differences.

Group Dynamics and Allocation of Advanced Heart Failure Therapies-Heart Transplants and Ventricular Assist Devices-By Gender, Racial, and Ethnic Group

Background US regulatory framework for advanced heart failure therapies (AHFT), ventricular assist devices, and heart transplants, delegate eligibility decisions to multidisciplinary groups at the center level. The subjective nature of decision-making is at risk for racial, ethnic, and gender bias. We sought to determine how group dynamics impact allocation decision-making by patient gender, racial, and ethnic group. Methods and Results We performed a mixed-methods study among 4 AHFT centers. For ≈ 1 month, AHFT meetings were audio recorded. Meeting transcripts were evaluated for group function scores using de Groot Critically Reflective Diagnoses protocol (metrics: challenging groupthink, critical opinion sharing, openness to mistakes, asking/giving feedback, and experimentation; scoring: 1 to 4 [high to low quality]). The relationship between summed group function scores and AHFT allocation was assessed via hierarchical logistic regression with patients nested within meetings nested within centers, and interaction effects of group function score with gender and race, adjusting for patient age and comorbidities. Among 87 patients (24% women, 66% White race) evaluated for AHFT, 57% of women, 38% of men, 44% of White race, and 40% of patients of color were allocated to AHFT. The interaction between group function score and allocation by patient gender was statistically significant (P=0.035); as group function scores improved, the probability of AHFT allocation increased for women and decreased for men, a pattern that was similar irrespective of racial and ethnic groups. Conclusions Women evaluated for AHFT were more likely to receive AHFT when group decision-making processes were of higher quality. Further investigation is needed to promote routine high-quality group decision-making and reduce known disparities in AHFT allocation.

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.

Female sex and advanced age are associated with invasive cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Limited data exist to describe sex-based differences in the severity of cytomegalovirus (CMV) infection after solid organ transplant (SOT). We sought to identify if a difference exists in likelihood of tissue-invasive disease between male and female SOT recipients and to understand how age affects this relationship.

METHODS

A retrospective cohort of 180 heart, liver, and kidney recipients treated for CMV was examined. A logistic regression model was developed to assess the relationship between female sex and CMV type (noninvasive vs. invasive). A secondary regression analysis looked at the relationship of invasive CMV with a variable combining sex with age above or below 50.

RESULTS

There were 37 cases of proven or probable invasive CMV, occurring in 30% of females versus 16% of males. After adjustment for potential confounders, females with CMV infection were significantly more likely to have invasive disease (odds ratio (OR) 2.69, 95% confidence interval (CI) 1.25-5.90, p = .01). Females 50 years or older were at particular risk compared with males under 50 years (adjusted OR 4.54, 95% CI 1.33-18.83, p = .02).

CONCLUSION

Female SOT recipients with CMV in our cohort were more likely than males to have tissue-invasive disease, with the highest risk among older females. Further prospective studies are warranted to explore underlying immunologic mechanisms.

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.

Diltiazem as a cyclosporine A-sparing agent in heart transplantation: Benefits beyond dose reduction

Diltiazem (DZ) is widely prescribed in transplant recipients because of its drug-drug interactions with calcineurin inhibitors (CNI). However, these interactions have been primarily investigated in renal transplantation, and data regarding the long-term efficacy and safety of DZ in orthotopic heart transplantation (OHT) are still sparse. Our study aimed to elucidate the extent to which the co-prescription of DZ reduces the dose required to maintain adequate blood levels of cyclosporine A (CsA) and the resulting effect on morbidity and mortality in OHT recipients. We performed a retrospective single-center analysis of OHT recipients on a long-term immunosuppressive regimen based on CsA and mycophenolate mofetil (MMF). The study population consisted of 95 adult OHT recipients with a mean follow-up of 15.8 ± 6.7 years. DZ was co-prescribed in 39 subjects (41.1%) and was associated with a 28.6% reduction of the mean CsA daily dose (P < .001). Patients on DZ had less frequent rejection episodes (P = .002), better renal function (P = .009) and a lower rate of end-stage renal disease (P = .008). Additionally, they developed later cardiac allograft vasculopathy (CAV). We observed no prognostic relevance of DZ co-prescription in univariate and multivariate Cox-regression analyses. In addition to reducing the CsA dose required to maintain adequate blood through levels, DZ may have nephroprotective properties in OHT. The co-administration of DZ may decelerate the development of CAV and reduce the frequency of the rejection episodes. However, the beneficial influence on morbidity has no impact on mortality.

Special Considerations in the Care of Women With Advanced Heart Failure

Advanced heart failure (AHF) is associated with increased morbidity and mortality, and greater healthcare utilization. Recognition requires a thorough clinical assessment and appropriate risk stratification. There are persisting inequities in the allocation of AHF therapies. Women are less likely to be referred for evaluation of candidacy for heart transplantation or left ventricular assist device despite facing a higher risk of AHF-related mortality. Sex-specific risk factors influence progression to advanced disease and should be considered when evaluating women for advanced therapies. The purpose of this review is to discuss the role of sex hormones on the pathophysiology of AHF, describe the clinical presentation, diagnostic evaluation and definitive therapies of AHF in women with special attention to pregnancy, lactation, contraception and menopause. Future studies are needed to address areas of equipoise in the care of women with AHF.

Trends in Hospital Admissions for Systolic and Diastolic Heart Failure in the United States Between 2004 and 2017

Heart failure (HF) affects 6 million people in the United States and costs $30 billion annually. It is unclear whether improvements in length of stay and mortality over the last few decades hold true for both systolic and diastolic HF. To better assess the epidemiological and economic burden of HF, we assessed the trends in outcomes and costs for both systolic and diastolic HF. We identified hospitalizations for systolic and diastolic HF in the National Inpatient Sample database and evaluated trends over the period from 2004 to 2017, adjusting for demographics and co-morbidities. The proportion of patients admitted with an exacerbation of systolic HF increased from 42% to 63% over the study period. We found an overall decreasing trend between 2004 and 2011 in the length of stay for HF in general with a sharper decrease in diastolic than systolic HF. Inpatient mortality decreased between 2004 and 2007 and stabilized between 2008 and 2016. Systolic HF was associated with higher mortality than diastolic HF. The total inflation-adjusted cost did not change significantly over the study period, with systolic HF costing, on average, $3,036 more than diastolic HF per admission. In conclusion, systolic HF overtook diastolic HF, accounting for most HF hospitalizations in 2008. The higher hospitalization costs for systolic HF relative to diastolic HF may have resulted, in part, from greater use of advanced support devices in patients with systolic HF.

The Canadian Women's Heart Health Alliance Atlas on the Epidemiology, Diagnosis, and Management of Cardiovascular Disease in Women - Chapter 5: Sex- and Gender-Unique Manifestations of Cardiovascular Disease

This Atlas chapter summarizes sex- and some gender-associated, and unique aspects and manifestations of cardiovascular disease (CVD) in women. CVD is the primary cause of premature death in women in Canada and numerous sex-specific differences related to symptoms and pathophysiology exist. A review of the literature was done to identify sex-specific differences in symptoms, pathophysiology, and unique manifestations of CVD in women. Although women with ischemic heart disease might present with chest pain, the description of symptoms, delay between symptom onset and seeking medical attention, and prodromal symptoms are often different in women, compared with men. Nonatherosclerotic causes of angina and myocardial infarction, such as spontaneous coronary artery dissection are predominantly identified in women. Obstructive and nonobstructive coronary artery disease, aortic aneurysmal disease, and peripheral artery disease have worse outcomes in women compared with men. Sex differences exist in valvular heart disease and cardiomyopathies. Heart failure with preserved ejection fraction is more often diagnosed in women, who experience better survival after a heart failure diagnosis. Stroke might occur across the lifespan in women, who are at higher risk of stroke-related disability and age-specific mortality. Sex- and gender-unique differences exist in symptoms and pathophysiology of CVD in women. These differences must be considered when evaluating CVD manifestations, because they affect management and prognosis of cardiovascular conditions in women.

Difference in absolute lymphocyte count among male and female heart transplant recipients

The impact of sex on immune composition in the setting of solid organ transplantation is unknown. Immunocompetent men and women have quantitative differences in multiple markers of immunity, including lymphocyte subsets. Lymphocytes are of particular interest given the routine use of medications targeted at cell-mediated immunity. The objective of this retrospective cohort study was to compare absolute lymphocyte count (ALC) measurements of male and female heart recipients immediately before, and 1 month after, transplantation. Data was collected on 375 adult recipients (104 female and 271 male) from 2000 to 2018 at a single center. Mean ALC was compared using Student's t-test. Women had higher mean ALC both at baseline (female 1.6 × 10³ cells/μl vs. male 1.3 × 10³ cells/μl; P < .001) and at 1 month post-transplantation (mean 1.2 × 10³ cells/μl vs. .8 × 10³ cells/μl; P < .001). This finding could have important implications for sex-based differences in predisposition to rejection or response to infection or vaccination.

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.

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).

Clinical presentation and outcomes in women and men with advanced heart failure

OBJECTIVE

To examine clinical characteristics and outcomes in women and men referred for advanced heart failure (HF) therapies such as left ventricular assist device (LVAD) or heart transplantation (HTx). Design: A retrospective study of 429 (23% women) consecutive adult HF patients not on inotropic or mechanical circulatory support with left ventricular ejection fraction ≤45% referred for assessment of advanced HF therapies at a single tertiary institution between 2002 and 2016. Clinical characteristics and outcomes were compared in women and men, and all patients underwent right heart catheterization (RHC). Results: At evaluation, women were younger than men (48 ± 13 vs. 51 ± 12 years, p = .02), and less likely to have ischemic cardiomyopathy. There were no significant differences in NYHA class, contemporary HF therapy use, or physical examination findings, except for lower jugular vein distension and body surface area in women. On RHC, women had lower cardiac filling pressures, but similar pulmonary vascular resistance and cardiac index. Peak oxygen uptake from cardiopulmonary exercise testing was similar in both sexes. At total follow-up time, there were 164 deaths (21% vs. 44%, p < .0001), 46 LVADs (3% vs. 13%, p = .005), 110 HTxs (32% vs. 25%, p = .15), and 82 HTxs without requiring LVAD (29% vs. 16%, p = .03) in women and men. The time from RHC to HTx (±LVAD) was significantly shorter in women compared to men. Female sex was significantly associated with higher survival independent of time-trend, age, and comorbidities. Conclusion: At evaluation, hemodynamics were less deranged in women. A higher proportion of women received HTx, their waitlist time was shorter, and survival greater.

Sex Differences in Patients Receiving Left Ventricular Assist Devices for End-Stage Heart Failure

OBJECTIVES

This study sought to use INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) results to evaluate sex differences in the use and clinical outcomes of left ventricular assist devices (LVAD).

BACKGROUND

Despite a similar incidence of heart failure in men and women, prior studies have highlighted potential underuse of LVADs in women, and studies of clinical outcomes have yielded conflicting results.

METHODS

Patients were enrolled from the INTERMACS study who underwent implantation of their first continuous-flow LVAD between 2008 and 2017, and survival analyses stratified by sex were conducted.

RESULTS

Among the 18,868 patients, 3,984 (21.1%) were women. At 1 year, women were less likely to undergo heart transplantation than men (17.9% vs. 20.0%, respectively; p = 0.003). After multivariable adjustments, women had a higher risk of death (hazard ratio [HR]: 1.15; 95% confidence interval [CI]: 1.07 to 1.23; p < 0.001) and were more likely to incur post-implantation adverse events, including rehospitalization, bleeding, stroke, and pump thrombosis or device malfunction. Although women younger than 50 years of age had an increased risk of death compared to men of the same age (HR: 1.34; 95% CI: 1.12 to 1.6), men and women 65 years of age and older had a similar risk of death (HR: 1.09; 95% CI: 0.95 to 1.24).

CONCLUSIONS

This study found that women had a higher risk of mortality and adverse events after LVAD. Only 1 in 5 LVADs were implanted in women, and women were less likely to receive a heart transplant than men. Further investigation is needed to understand the causes of adverse events and potential underuse of advanced treatment options in women.

Perioperative Considerations Regarding Sex in Solid Organ Transplantation

Sex plays a role in all stages of the organ transplant process, including listing, sex/size matching of organs, complications, graft survival, and mortality. Sex-related differences in organ transplantation are likely multifactorial related to biological and social characteristics. More information is needed to determine how sex-related differences can lead to improved outcomes for future donors and recipients of solid organs. This article provides an overview on the impact of sex on various types of solid organ transplant, including kidney, pancreas, liver, lung, and heart transplants.

The Influence of Sex Differences on Cardiopulmonary Exercise Metrics Following Heart Transplant

BACKGROUND

Previous work has shown sex-related differences in cardiopulmonary responses in patients with heart failure (HF); however, sex differences following heart transplant (HTx) have not been examined. Thus, we hypothesized women would demonstrate lower peak oxygen uptake (VO_2peak) but similar ventilatory efficiency (V_E/VCO₂ slope) compared with men prior to HTx. Furthermore, we hypothesized that, following HTx, women would exhibit greater improvements in VO_2peak and V_E/VCO₂ slope compared with men.

METHODS

HTx patients with cardiopulmonary exercise testing (CPET) between 2007 and 2016 were included. Pre-HTx CPET occurred within 24 months pre-HTx with post-HTx CPET within 12 months following HTx. VO_2peak was measured via standard protocol. V_E/VCO₂ slope was calculated using rest-peak ventilation (V_E) and carbon dioxide production (VCO₂).

RESULTS

Eighty-eight patients (Men [M]: n = 63, age: 55 ± 12 years; Women [W]: n = 25, age: 47 ± 11 years) were assessed. Pre-HTx VO_2peak (M: 13.9 ± 5.0 vs W: 11.6 ± 3.9 mL/kg/min, P = 0.17) and V_E/VCO₂ slope (M: 42 ± 12 vs W: 46 ± 18, P = 0.53) were not different between sexes. Overall, VO_2peak (Pre: 13.3 ± 4.8 vs Post: 18.4 ± 4.8 mL/kg/min, P < 0.01) and V_E/VCO₂ slope (Pre: 43 ± 14 vs Post: 37 ± 6, P = 0.02) improved following HTx. Post-VO_2peak (M: 19.0 ± 4.8 vs W: 16.8 ± 4.5 mL/kg/min, P = 0.24) and V_E/VCO₂ slope (M: 37 ± 6 vs W: 37 ± 7, P = 0.99) and delta VO_2peak (M: 5.0 ± 4.8 vs W: 5.3 ± 4.9 mL/kg/min, P = 0.85) and V_E/VCO₂ slope (M: -5 ± 11 vs W: -9 ± 17, P = 0.29) were not different between sexes.

CONCLUSIONS

These data demonstrate that cardiopulmonary improvements following HTx patients occur for both sexes. Importantly, women show similar significant functional improvements following HTx compared with men.

Sex differences in preformed panel-reactive antibody levels and outcomes in patients undergoing heart transplantation

BACKGROUND

Sex differences in panel-reactive antibody (PRA) levels in heart transplant recipients and their association with transplant-related outcomes are mostly unknown.

METHODS

In 20 181 (24.7% women) first-time heart transplant recipients included from July 2004 to March 2015 in the prospective Organ Procurement and Transplantation Network (OPTN), we studied sex differences in most recent (mr) and peak (p)PRA and outcomes (graft failure, rejection, cardiac allograft vasculopathy [CAV], retransplantation, and mortality). Median follow-up (all-cause mortality) was 6 years. Analyses are based on OPTN data (March 6, 2017).

RESULTS

MrPRA levels were associated with all-cause mortality (hazard ratio, 95% confidence interval: class I 1.03, 1.01-1.04, P < 0.001) and acute rejection (class II 1.08, 1.03-1.14, P = 0.0044). PPRA levels were associated with all-cause mortality (class I 1.02, 1.00-1.04, P = 0.015) and CAV (class II 1.03, 1.01-1.06, P = 0.020). Sex interactions were seen for the association of pPRA and graft failure with a higher risk in women, and for pPRA and CAV with a higher risk in men.

CONCLUSIONS

PRA were associated with different transplant-related outcomes in both sexes. However, women with elevated pPRA were shown to be at higher risk for graft failure, whereas higher levels of pPRA were more hazardous for men in developing CAV.

Infectious complications after heart transplantation in patients screened with gene expression profiling

BACKGROUND

The risk of infection after heart transplantation is highest within the first year and represents the leading cause of early mortality. In this cohort of patients enrolled in the Outcomes AlloMap Registry (OAR), we sought to describe infection episodes (IEp) resulting in hospitalization, in the early (<1 year) and late (≥1 year) post-transplant period and determine the impact of immunosuppression on incidence of infection.

METHODS

The primary aim was to assess the incidence and nature of IEp. The secondary aim was to evaluate the effect of potential risk factors, such as recipient age; sex; body mass index; panel-reactive antibodies; cytomegalovirus (CMV) primary mismatch; prednisone, tacrolimus, and sirolimus levels; and gene expression profile (GEP) score, in the development of IEp.

RESULTS

The OAR comprises 1,504 patients, of whom 220 patients (14.6%) had an IEp during a median follow-up period of 382 days (interquartile range [IQR] 230 to 579 days). The cause-specific 5-year hazard ratio for any infection was 2.029 (p = 0.12). The pattern of early infection was consistent with nosocomial and opportunistic causes, whereas later infection was consistent with late-onset opportunistic and community-acquired etiologies. Sixty-two percent of the infections occurred early. In the time-dependent analysis, higher prednisone dose (log prednisone, hazard ratio [HR] 1.30, p = 0.022) was the most significant risk factor for all IEp.

CONCLUSIONS

In the OAR cohort, the majority of infections occurred within 1 year after transplantation. Clinicians may consider more aggressive prednisone withdrawal in low-risk patients to reduce IEp.

Practice patterns to improve pre and post-transplant medication adherence in heart transplant centres: a secondary data analysis of the international BRIGHT study

BACKGROUND

As medication non-adherence is a major risk factor for poor post-transplant outcomes, we explored how adherence is assessed, enhanced and integrated across the transplant continuum.

AIM

The aim of this study was to study practice patterns regarding pre- and post-transplant medication adherence assessment and interventions in international heart transplant centres.

METHODS

We used data from the Building Research Initiative Group: chronic illness management and adherence in heart transplantation (BRIGHT) study, a cross-sectional study conducted in 36 heart transplant centres in 11 countries. On a 27-item questionnaire, 100 clinicians (range one to five per centre) reported their practice patterns regarding adherence assessment and intervention strategies pre-transplant, immediately post-transplant, less than one year, and one or more year post-transplant. Educational/cognitive, counselling/behavioural and psychosocial/affective strategies were assessed. Clinicians' responses (intervention present vs. absent; or incongruence in reporting intervention) were aggregated at the centre level.

RESULTS

The adherence assessment method most commonly used along the transplant continuum was questioning patients (range 75-88.9%). Pre-transplant, all three categories of intervention strategy were applied. Providing reading materials (82.9%) or instructions (68.6%), involving family or support persons in education (91.4%), and establishing partnership (91.4%) were used most frequently. Post-transplant, strategies closely resembled those employed pre-transplant. Training patients (during recovery) and cueing were more often applied during hospitalisation (74.3%). After the first year post-transplant, except for motivational interviewing (25.7-28.6%), the number of strategies decreased.

CONCLUSIONS

Across the transplant continuum, diverse adherence interventions are implemented; however, post-transplant, the frequency of adherence interventions decreases. Therefore, increased investment is necessary in long-term adherence interventions.