When looking at the distribution of HTxs by race and ethnicity, it was found that Black and Hispanic surgeons have remained far below their respective US population percentages in the context of both adult and pediatric HTxs. This trend is likely partially due to there being less Black and Hispanic students entering medical school; therefore, there are fewer applicants for positions as HTx surgeons [13]. The proportion of Asian surgeons, on the other hand, has remained above the respective proportion of Asians in the US population. This could be due to cardiac transplants being typically performed at academic centers at which Asian surgical faculty have been previously found to be overrepresented when compared with the US population [14].

The analysis by sex found that the number of female HTx surgeons remained below 5% from 2000–2020. The greatest increase, from 2.5% to 4.7%, was seen from 2017 to 2018 in the context of adult HTxs. This could have been an effect of the steady increase in the number of women in cardiothoracic surgery as a specialty from the year 2000. Additionally, more integrated and fast-track residency programs in cardiothoracic surgery have been created in the past few years [15]. These could be serving as an incentive for women to enter the field, as they allow completion of training in a shorter amount of time. This differs from the discrepancy between the HTx percentages when looking at race and ethnicity, because medical schools do not lack in the representation of women as they do with minority populations. This indicates that there could be a problem during medical school in recruiting women to cardiothoracic surgery, rather than a problem with accepting women to medical school, as is the case with minority individuals.

The general United States population was used as a baseline rather than the practicing physician population because the barriers that exist to becoming a cardiothoracic transplant surgeon also exist for other subspecialties in medicine. Social determinants of health, such as income and access to education, affect the general population from entering the practicing physician population [16]. Structural racism, discrimination, and implicit bias exist as barriers that impact minorities within the medical community [17]. Additionally, a physician workforce should be representative of the population it stems from and serves. The practicing physician population must be explored in its entirety for new trends in diversity before it can be used as a baseline population for a subspecialty of physicians.

This study led to more information about the trends in diversity over the last 20 years within the cardiothoracic surgery workforce in the context of heart transplantation. It was generalized across the entire United States, but it would be interesting to investigate how historical patterns affect the sex and racial disparities across different regions in the United States that are seen today. For example, it could be theorized that there could be a higher proportion of Black surgeons in the Southeastern United States in the current day due to the transatlantic slave trade. Immigration patterns of different races and ethnicities should be explored as well, as minority status is separate from immigration status. The lack of diversity present in the cardiothoracic surgery workforce in the context of heart transplants demonstrates the need to investigate the demographic patterns in other sub-specialized fields of medicine to determine whether this lack of diversity is present across the board, or whether it is only occurring in some fields such as surgery as whole [18]. Future implications of this type of research include investigating the need for policy changes at institutional, community, and societal levels to address this lack of diversity. There should be incentives and support provided for underrepresented individuals at each of these levels of healthcare. These findings serve as objective data illustrating the need for more research to analyze the root of the disparities seen in cardiothoracic surgery.