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32 Diversity and Access in Heart Transplantation
403
also decreased, from 16.7 to 7.1% and from 13.1
to 7.1%, respectively, over the same interval
[8]. An analysis shows that fewer than 15% of
all listed candidates of any demographic group
were noted to be working for income. As political tides turn, the availability of low-cost insurance to people of limited income fluctuates. As
the above findings demonstrate, the availability
of public health insurance has a considerable
impact on expanding HTx access, particularly in
financially disadvantaged communities, and is a
vital tool to bridge the disparities gap.
Socioeconomic Stressors and Heart Transplant-Related Outcomes
The social determinants of health play an important role in the observed high mortality after
HTx for racial minorities. These factors have
been nicely examined in multiple analyses.
Suarez-Pierre et al. evaluated the impact of the
social vulnerability index (SVI) on outcomes
after HTx among 23,700 patients undergoing
HTx between 2012 and 2021 and found lower
5-year survival, higher incidences of 5-year
hospital readmission, and graft rejection among
individuals living in highly vulnerable communities (SVI ≥ 75%) compared to those living in
less vulnerable communities (SVI < 75%) [9].
In a study of 32,494 adult HTx recipients from
2005 to 2020, in which the authors performed
a detailed analysis of ZIP code-level socioeconomic disadvantage using the Distressed
Communities Index, which includes parameters
such as educational level, poverty, unemployment, housing vacancies, median income and
business growth [5]. Comparing HTx recipients
from distressed communities (n = 5,043) with
all others (n = 27,451), the authors found that,
not surprisingly, recipients from the most distressed communities were more likely to be of
racial minorities, had lower educational levels
and were more likely to have public insurance
[5]. Such disadvantaged patients received HTx
at lower-volume centers and lived farther away
from their transplant centers. Furthermore, HTx
recipients from distressed communities suffered
from acute rejection at higher rates before discharge from the index hospitalization and also
had higher 1-year readmission rates and worse
5-year survival [5]. This study illustrates how
the comprehensive burden of social and financial stressors interplay in their impact on postHTx outcomes. Similar to the above study,
analyses of racial and ethnic groups over the
span of 3 decades have consistently identified
Black patients to be at higher risk of mortality
after cardiac transplantation [10, 11]. Apart from
the social determinants of health, other contributing factors have been hypothesized, including
racial and ethnic differences between the donor
and recipient and immunologic and genetic mismatch. Given the limited supply of donor hearts,
it is imperative to dissect the factors leading to
disparities among different patient groups to
achieve equitable access to HTx and improve
patient outcomes.
The New Allocation System and Its Impact on Improved Access to Transplantation for Racial Minorities
The primary directive of the United Network
for Organ Sharing (UNOS) is the Final Rule:
equitable allocation of organs. Various iterations
of the organ allocation system have occurred
through the years, striving to mitigate the inherent inequalities in access to transplantation
resulting from arbitrary geographical boundaries. The older geographic sharing methodology created longer wait times for patients in
diverse, highly populated regions, potentially
affecting minority recipients more. In a previous study of trends, Liu et al. demonstrated
that the proportion of racial and ethnic minorities increased from 1987 to 2009, and by 2005
to 2009, accounted for nearly one-third of all
transplants [12]. In 2018, UNOS revised the
organ allocation system from three tiers to six
tiers, incorporating broader regional sharing
for the sickest patients, thus aiming to remedy
geographic inequities. An analysis by Chouairi
et al. based on a decade of data from the UNOS
404 A. P. Nikolova
registry examines HTx outcomes and trends
among 32, 353 patients who self‐identified as
Black, Hispanic, and White pre- and post-thenew allocation system [13]. Over the span of
a decade, the study reports an increased proportion of self‐identified Black and Hispanic
patients who were listed for HTx (from 21.7 to
28.2% and from 7.7 to 9.0%, respectively, from
2011 to 2020) [13]. Similarly, the proportion
of Black candidates transplanted has increased
steadily from 20.8 to 27.3%. However, the
improved transplantation rates for minorities
appear to be proportionately less compared to
the rising rates in the prevalence of end-stage
HF in these communities [13]. The study by
Chouairi et al. also found an increased likelihood of transplantation among all racial/ethnic
groups after the change in the allocation system [13]. However, Black candidates were still
significantly less likely to be transplanted after
allocation amendments, despite similar acuity and listed status [13]. On the other hand, the
likelihood of transplantation among Hispanic
and White candidates was similar after the 2018
policy changes [13]. Although such efforts to
improve access to HTx for vulnerable groups are
fruitful, much work still remains to be done.
Gender Disparities
It has been well established that the prevalence of HF in women is higher than in men,
and yet, women are less likely to be referred to
or receive HTx and LVAD [14]. However, the
exact denominator of the women afflicted with
this condition is still unknown. Alarmingly,
women account for 54% of HF-related deaths,
but only comprise 21% of LVAD recipients and
25% of HTx waitlist candidates [15, 16]. In
a multicenter analysis of patients referred for
advanced HF therapies at nine centers in the
United States, only 26.6% were women, corroborating the under-utilization of advanced HF
therapies in female patients [17]. Factors that
could account for the lower access to needed
therapies for women include social determinants of health, frailty burden, higher rates of
allosensitization, and others [16]. However,
recent studies shed light on the conscious and
unconscious biases that might be at play in
these observed referral patterns. In an analysis
using identical patient vignettes, HF specialists
tended to consider that the same level of available social support was adequate for men but not
for women [18]. The same study showed that
having children was considered a liability for
women, particularly Black women, but not for
men [18]. Another single-center analysis from
Emory University found that women were less
likely to be considered eligible for advanced
therapies than men despite similar social support
and SIPAT (Stanford Integrated Psychosocial
Assessment for Transplantation, a comprehensive psychosocial assessment tool) scores [19].
In terms of patients already listed for HTx, data
indicate that women suffer from higher waitlist mortality, particularly at the highest acuity
tiers, compared to men. In the previous 3-tiered
heart allocation system, women had an adjusted
hazard ratio (aHR) of 1.20 of waitlist mortality compared to men, even after adjustment
for relevant clinical characteristics [20]. These
sex disparities in mortality rates unfortunately
remain in the current 6-tiered allocation system
[20]. Of candidates waiting for HTx as Status 1,
women have a significantly lower rate of HTx
compared with men after adjustment for clinical characteristics (aHR: 0.74 [95% CI: 0.62–
0.88]; P < 0.0001) and a significantly higher
rate of delisting for death or clinical deterioration (aHR: 1.48 [95% CI: 1.05–2.09]; P = 0.026)
[20]. Possible factors that negatively impact
women’s waitlist outcomes include vascular
access barriers for temporary mechanical circulatory support (tMCS) devices due to smaller
caliber vessels in women, as well as complications from MCS devices [16, 20]. More data are
needed on the safety and adverse events associated with tMCS devices in women. Other postulated barriers to transplantation in female and
Black patients are immunologic factors, such as
higher rates of allosensitization [21]. The presence of anti-HLA antibodies limits the donor
pool size, increases waitlist mortality, and leads
to increased post-HTx rejection rates [22]. In
32 Diversity and Access in Heart Transplantation
405
women, in particular, a history of pregnancy is
an important risk factor for allosensitization that
uniquely disadvantages them. There is a lack
of large, multicenter studies on sex differences
in response to desensitization therapies, listing
practices, and transplant outcomes. Studies have
shown that among sensitized HTx candidates,
women with a history of pregnancy are at higher
risk of antibody-mediated rejection (AMR) than
recipients without a history of pregnancy [23]. A
study reported that, on average, women experienced more episodes of acute rejection than men
and also tended to have higher rates of moderate
to severe rejection on biopsies performed within
the first year post-HTx [23]. Another singlecenter study similarly showed that women had
a greater risk of developing AMR than men at
1-year follow-up [23]. In that study, AMR treatment response was similar between the sexes,
and there was no difference in rejection-related
mortality [23]. However, calculated panel reactive antibody levels do not completely account
for the increased risk of delisting or waitlist
mortality observed in women, nor did the use of
extracorporeal membrane oxygenation [20].
Future Directions
Solutions to address these racial and gender disparities are direly needed but not easy to implement as they affect the root structure of our
society. A recent statement from the American
Heart Association highlights structural racism
is a foundational element of these disparities in
care [24]. This structural racism is pervasive—in
the quality of housing, the neighborhood environments, the opportunities for educational and
economic advancement, etc. A fulcrum point of
such change can be the fair inclusion of minorities in clinical trials, access to affordable public
insurance, and the creation of bridges between
academic institutions and local community hospitals and medical centers. A guiding force in
these changes should be fair societal policies
that address the very mechanisms underlying the
disparities in cardiovascular care.
References
1. Khariton Y, Nassif ME, Thomas L, Fonarow GC,
Mi X, DeVore AD, et al. Health status disparities
by sex, race/ethnicity, and socioeconomic status
in outpatients with heart failure. JACC Heart Fail.
2018;6(6):465–73.
2. Breathett K, Liu WG, Allen LA, Daugherty SL,
Blair IV, Jones J, et al. African Americans are less
likely to receive care by a cardiologist during an
intensive care unit admission for heart failure. JACC
Heart Fail. 2018;6(5):413–20.
3. Glynn P, Lloyd-Jones DM, Feinstein MJ, Carnethon
M, Khan SS. Disparities in cardiovascular mortality related to heart failure in the United States. J Am
Coll Cardiol. 2019;73(18):2354–5.
4. Lui C, Fraser CD III, Zhou X, Suarez-Pierre
A, Kilic A, Zehr KJ, et al. Racial disparities in
patients bridged to heart transplantation with
left ventricular assist devices. Ann Thorac Surg.
2019;108(4):1122–6.
5. Chen Q, Malas J, Emerson D, Megna D, Catarino P,
Esmailian F, et al. Heart transplantation in patients
from socioeconomically distressed communities. J
Heart Lung Transplant. 2024;43(2):324–33.
6. Breathett K, Knapp SM, Carnes M, Calhoun E, Sweitzer
NK. Imbalance in heart transplant to heart failure mortality ratio among African American, Hispanic, and
White patients. Circulation. 2021;143(24):2412–4.
7. Pagani FD. Insurance coverage and heart transplant
outcomes. Circul Cardiovasc Qual Outcomes Am
Heart Assoc. 2016;9:501–3.
8. Breathett K, Allen LA, Helmkamp L, Colborn K,
Daugherty SL, Khazanie P, et al. The Affordable
Care Act Medicaid expansion correlated with
increased heart transplant listings in AfricanAmericans but not Hispanics or Caucasians. JACC
Heart Fail. 2017;5(2):136–47.
9. Suarez-Pierre A, Iguidbashian J, Kirsch MJ, Cotton
JL, Quinn C, Fullerton DA, et al. Importance
of social vulnerability on long-term outcomes
after heart transplantation. Am J Transplant.
2023;23(10):1580–9.
10. Kilic A, Higgins RSD, Whitson BA, Kilic A. Racial
disparities in outcomes of adult heart transplantation. Circulation. 2015;131(10):882–9.
11. Allen JG, Weiss ES, Arnaoutakis GJ, Russell SD,
Baumgartner WA, Conte JV, et al. The impact of
race on survival after heart transplantation: an analysis of more than 20,000 patients. Ann Thorac Surg.
2010;89(6):1956–64.
12. Liu V, Bhattacharya J, Weill D, Hlatky MA.
Persistent racial disparities in survival after heart
transplantation. Circulation. 2011;123(15):1642–9.
13. Chouairi F, Fuery M, Clark KA, Mullan CW,
Stewart J, Caraballo C, et al. Evaluation of racial
and ethnic disparities in cardiac transplantation. J
Am Heart Assoc. 2021;10(17):e021067.
406 A. P. Nikolova
14. Morris AA, Khazanie P, Drazner MH, Albert
NM, Breathett K, Cooper LB, et al. Guidance for
timely and appropriate referral of patients with
advanced heart failure: a scientific statement from
the American Heart Association. Circulation.
2021;144(15):e238-50.
15. Hsich EM, Blackstone EH, Thuita L, McNamara
DM, Rogers JG, Ishwaran H, et al. Sex differences
in mortality based on united network for organ sharing status while awaiting heart transplantation. Circ
Heart Fail. 2017;10(6):e003635.
16. DeFilippis EM, Nikolova A, Holzhauser L, Khush
KK. Understanding and investigating sex-based differences in heart transplantation: a call to action.
Heart Fail. 2023;11(9):1181–8.
17. Herr JJ, Ravichandran A, Sheikh FH, Lala A, Chien
CV, Hsiao S, et al. Practices of referring patients
to advanced heart failure centers. J Card Fail.
2021;27(11):1251–9.
18. Breathett K, Yee E, Pool N, Hebdon M, Crist JD,
Yee RH, et al. Association of gender and race with
allocation of advanced heart failure therapies.
JAMA Netw Open. 2020;3(7):e2011044–e2011044.
19. Steinberg RS, Nayak A, Burke MA, Aldridge M,
Raja Laskar S, Bhatt K, et al. Association of race
and gender with primary caregiver relationships and
eligibility for advanced heart failure therapies. Clin
Transplant. 2022;36(1):e14502.
20. DeFilippis EM, Masotti M, Blumer V, Maharaj V,
Cogswell R. Sex-specific outcomes of candidates
listed as the highest priority status for heart transplantation. Circ Heart Fail. 2023;16(6):e009946.
21. Morris AA, Cole RT, Veledar E, Bellam N, Laskar
SR, Smith AL, et al. Influence of race/ethnic differences in pre-transplantation panel reactive antibody
on outcomes in heart transplant recipients. J Am
Coll Cardiol. 2013;62(24):2308–15.
22. Kransdorf EP, Kittleson MM, Patel JK, Pando MJ,
Steidley DE, Kobashigawa JA. Calculated panelreactive antibody predicts outcomes on the heart
transplant waiting list. J Heart Lung Transplant.
2017;36(7):787–96.
23. Nguyen LS, Coutance G, Salem JE, Ouldamar S,
Lebreton G, Combes A, et al. Effect of recipient
gender and donor-specific antibodies on antibodymediated rejection after heart transplantation. Am J
Transplant. 2019;19(4):1160–7.
24. Churchwell K, Elkind MSV, Benjamin RM, Carson
AP, Chang EK, Lawrence W, et al. Call to action: structural racism as a fundamental driver of health disparities: a presidential advisory from the American Heart
Association. Circulation. 2020;142(24):e454-68.