Sex differences in patients undergoing heart transplantation and LVAD therapy

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.

Gender and Race Differences in HeartMate3 Left Ventricular Assist Device as a Bridge to Transplantation

BACKGROUND

Gender and racial disparities exist after left ventricular assist device (LVAD) implantation. Compared with older devices, the HeartMate 3 (HM3) (Abbott Cardiovascular) has demonstrated improved survival. Whether HM3 differentially improves outcomes by gender or race and ethnic groups is unknown.

OBJECTIVES

The purpose of this study is to examine differences by gender and race in the use of HM3 among patients listed for heart transplantation (HT) and associated waitlist and post-transplant outcomes.

METHODS

The authors examined all patients (20% women, 33% Black) who received LVADs as bridge to transplantation (BTT) between January 2018 and June 2020, in the OPTN (Organ Procurement and Transplantation Network) database. Trends in use of HM3 were evaluated by gender and race. Competing events of death/delisting and transplantation were evaluated using subdistribution hazard models. Post-transplant outcomes were evaluated using multivariate logistic regression adjusted for demographic, clinical, and donor characteristics.

RESULTS

Of 11,524 patients listed for HT during the study period, 955 (8.3%) had HM3 implanted as BTT. Use of HM3 increased for all patients, with no difference in use by gender (P = 0.4) or by race (P = 0.2). Competing risk analysis did not demonstrate differences in transplantation or death/delisting in men compared with women (HT: adjusted HR [aHR]: 0.92 [95% CI: 0.70-1.21]; death/delisting: aHR: 0.91 [95% CI: 0.59-1.42]), although Black patients were transplanted fewer times than White patients (HT: aHR: 0.72 [95% CI: 0.57-0.91], death/delisting: aHR: 1.36 [95% CI: 0.98-1.89]). One-year post-transplant survival was comparable by gender (aHR: 0.52 [95% CI: 0.21-1.70]) and race (aHR: 0.76 [95% CI: 0.34-1.70]), with no differences in rates of stroke, acute rejection, or graft failure.

CONCLUSIONS

Use of HM3 among patients listed for HT has increased over time and by gender and race. Black patients with HM3 were less likely to be transplanted compared with White patients, but there were no differences in post-transplant outcomes between these groups or between men and women.

Advanced Heart Failure Characteristics and Outcomes in Women and Men

BACKGROUND

The epidemiology and pathophysiology of heart failure (HF) differ in women and men. Whether these differences extend to the subgroup of patients with advanced HF is not well defined.

METHODS AND RESULTS

This is a retrospective cohort study of all adult Olmsted County, Minnesota residents with advanced HF (European Society of Cardiology criteria) from 2007 to 2017. Differences in survival and hospitalization risks in women and men following advanced HF development were examined using Cox proportional hazard regression and Andersen-Gill models, respectively. Of 936 individuals with advanced HF, 417 (44.6%) were women and 519 (55.4%) were men (self-reported sex). Time from development of HF to advanced HF was similar in women and men (median 3.2 versus 3.6 years). Women were older at diagnosis (mean age 79 versus 75 years), less often had coronary disease and hyperlipidemia, but more often had hypertension and depression (P<0.05 for each). Advanced HF with preserved ejection fraction was more prevalent in women than men (60% versus 30%, p<0.001). There were no differences in adjusted risks of all-cause mortality (hazard ratio [HR], 0.89 [95% CI, 0.77-1.03]), cardiovascular mortality (HR, 0.85 [95% CI, 0.70-1.02]), all-cause hospitalizations (HR, 1.04 [95% CI, 0.90-1.20]), or HF hospitalizations (HR, 0.91 [95% CI, 0.75-1.11]) between women and men. However, adjusted cardiovascular mortality was lower in women versus men with advanced HF with reduced ejection fraction (HR, 0.72 [95% CI, 0.56-0.93]).

CONCLUSIONS

Women more often present with advanced HF with preserved ejection fraction and men with atherosclerotic disease and advanced HF with reduced ejection fraction. Despite these differences, survival and hospitalization risks are largely comparable in women and men with advanced HF.

The Canadian Women's Heart Health Alliance ATLAS on the Epidemiology, Diagnosis, and Management of Cardiovascular Disease in Women - Chapter 9: Summary of Current Status, Challenges, Opportunities, and Recommendations

This final chapter of the Canadian Women's Heart Health Alliance "ATLAS on the Epidemiology, Diagnosis, and Management of Cardiovascular Disease in Women" presents ATLAS highlights from the perspective of current status, challenges, and opportunities in cardiovascular care for women. We conclude with 12 specific recommendations for actionable next steps to further the existing progress that has been made in addressing these knowledge gaps by tackling the remaining outstanding disparities in women's cardiovascular care, with the goal to improve outcomes for women in Canada.

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.