Diversity in Cardiology

A Collaboration Between Two Colleagues Seeks to End Research Disparities


Shoa Clarke and Catherine Tcheandjieu were brought together, as many at Stanford are, by their shared interests. In their case it was the lab of faculty member—Tim Assimes, MD, associate professor of cardiovascular medicine—that provided the spark that led to their collaboration. And their excellent work, both together and apart, is only just getting started.

A Great Collaboration

Catherine Tcheandjieu, PhD, who recently began her fifth year as a Stanford postdoc in cardiovascular medicine and pediatrics, came to Stanford from abroad: she trained as a doctor in veterinary medicine and earned her PhD in genetic epidemiology in Paris before she arrived stateside.

Shoa Clarke, MD, PhD, is currently an instructor in the department of medicine and the department of pediatrics at Stanford, but his history with the university goes way back. He attended medical school at Stanford as a MD/PhD student, earning a PhD in genetics.

And after residency training on the East Coast, he returned to Stanford in 2017 for his cardiology fellowship (completed in 2020) before becoming an instructor.

Clarke and Tcheandjieu met in Assimes’ lab, and they started collaborating almost immediately.

“Shoa is very much interested in the same research questions that I’m interested in,” Tcheandjieu explains, “How can we improve genomic research for underrepresented minorities and create some precision medicine tool that is also applicable to those individuals?”

Identifying the Problem

The first step was to identify the problem, which is a relatively simple but systemic and devastating one: precision medicine and genomics have both advanced greatly over the past few decades, but the research data used for advancements have come almost exclusively from white populations.  

Clarke explains that this is because most genomics research pulls data from biobanks and data sets from the U.K. or other U.S. studies that were not diverse. “Essentially all of the data behind these tests comes from studies of white populations and when these scores are applied to other people--most of the world's population is not white--they don't work as well,” he states.  “The world of precision medicine’s been going on like this and some groups are almost systematically put aside, which means that all the progress cannot be applied to them.”  Tcheandjieu agrees, “You can't really use that science and translate it to another person.”

Importantly, Clarke notes that categories of race and ethnicity are not defined by biology or genetics. Still, discussing race is critical to acknowledging the structural racism in genomics research that led to the current disparities. Across different racial and ethnic groups, patterns of genetic ancestry vary, reflecting the history of our ancestors' migration. The majority of research participants to date have genomes of predominantly European ancestry. “People with more complex ancestry or ancestry from other parts of the globe, people like me and Catherine, are woefully understudied,” Clarke explains.

So for Tcheandjieu and Clarke’s first collaboration, they conducted a study on the current state of human cardiovascular genomics. They outline how racial disparities have propagated down the translational research pipeline, stating: “If not adequately addressed, biases in genomics research will further compound the existing health disparities that face underrepresented and marginalized populations.”

“The whole point of this review was to highlight the problem that is actually very persistent in the literature,” Tcheandjieu says.

Steps Toward a Solution

Once you identify a problem, the next step is finding a solution. Tcheandjieu and Clarke are now working together on that.  Clarke was recently awarded a Chair Diversity Investigator Award that includes funding to help him further his cause. Both have worked with Assimes with his work for the Million Veteran Program, a national research project in which veterans who receive care at VA hospitals donate their medical records and genetic information to be analyzed by scientists.  Veterans, Clarke explains, are a far more representative cross-section of race and ethnicities than some of these other data sets.  “The diversity of US veterans is very similar to the diversity of the US population,” he states.

Clarke has also worked with the Global Lipids Genetics Consortium or GLGC on a study of over a million subjects including hundreds of thousands of subjects who are carry diverse genetic ancestry, including African Americans as well as Africans, Hispanics, and Asians.  “That effort is far more diverse than any previous genetic study of lipids,” he concludes.

And there’s also TOPMed, an ongoing effort to generate multi-omics data (including whole-genome sequencing) for several diverse US clinical research cohorts. Using these data, Clarke is combining outcomes data across multiple studies in order to identify rare genetic variants that impact coronary artery disease risk.     

Clarke says, “My hope is that these complementary efforts will allow us to integrate multiple forms of data to improve our ability to identify genetic risks for heart disease in understudied populations.”

A JEDI Champion

As well as collaborating with Clarke, Tcheandjieu has been highly active on campus, earning herself the  Postdoc JEDI Champion Award for her efforts.  In her five years at Stanford, she’s been highly involved in every aspect of Stanford postdoc life, but some of her greatest commitments have been equity focused.

“I love doing advocacy work and I’ve worked closely with a lot of organizations to advocate for postdocs and help improve our lives as postdocs at Stanford,” she explains.  She’s worked on equity her whole career, but just a smattering of her work at Stanford shows us that she’s a very busy (and a very dedicated) woman.

Through her work with pediatrics she’s been deeply involved with the Stanford Pediatric Advancing Anti-Racism Coalition (or SPAARC) as SPAARC’s postdoc representative.  There she focused on working with the recruitment and retention team to determine “how we can improve representation of minorities in the Department of Pediatrics and how we can have an environment that is more fair and inclusive.”  She saw herself in some ways as “the voice of the postdocs,” discussing what it’s like to be a minority postdoc at Stanford and some of her own lived experiences in order to further SPAARC’s goals.

She and others also came up with several recommendations as well.  One of the simplest ones involved funding: the office of postdoctoral affairs has an initiative called PRISM, which brings graduate students from various minority groups to campus.  The selected students have interest in doing research at Stanford and the program connects them to Stanford faculty. The problem, however, is the money.  If a faculty member and a potential postdoc want to work together, they still have to find the money to sponsor the postdoc’s work, and if they can’t, “that’s one less minority,” as Tcheandjieu points out.  Her suggestion was that the Department of Pediatrics could work on leveraging funds to use specifically for these PRISM pairings, set aside to fund underrepresented minority students.

Another one of Tcheandjieu’s major initiatives is BlackinCardio, a Twitter account she co-founded to highlight and create networking opportunities for Black researchers and trainees in the cardiovascular sciences. The account also hosts Black in Cardio week (this year falling in early December).  The full effort has many goals, as Tcheandjieu explains. “It’s an opportunity to raise awareness about cardiovascular disease and see if we can create a form of networking for trainees, like an accounting of who the Black cardiovascular researchers are, so the next generation knows who to contact,” she says.

Tcheandjieu also worked on a project with Assimes and Clarke (now in pre-print) that is studying the genetic risk factors for coronary artery diseases involved in people of various ancestries. The project, a multi-ethnic genome-wide association study of coronary artery disease involving nearly a quarter of a million cases, has once again highlighted the importance of including more diversity in these kinds of genetic studies.

And that’s not all! Tcheandjieu is also involved in the Stanford University Postdoc Association (SURPAS) and their Diversity Perspective Speaker Series, which brings someone with what Tcheandjieu describes as “substantial JEDI (or justice, equity, diversity, and inclusion) work at the highest level” to speak to Stanford postdocs at a seminar about how best to move forward with equity issues. 

The Importance of Representation

"It’s important for all Americans to be exposed to people from different backgrounds so that they know how to respect people outside of their world.

“The world of research itself lacks representation,” Tcheandjieu says. “There are very few researchers from underrepresented minorities and sometimes because these researchers are not from those communities, they can make mistakes or make conclusions that can hurt those communities.”  A more diverse body of both researchers and research benefits everyone, she explains.  “At the end of the day this really matters a lot. Respect also comes from people that have high positions, and that can even change how for example the Black community is viewed in this country.  If you have Black people in important positions, like Black faculty at Stanford, the next generation will be used to seeing those things and just through our body of work we can help decrease bias.”   

“It’s important for all Americans to be exposed to people from different backgrounds so that they know how to respect people outside of their world,” Tcheandjieu concludes.

Tcheandjieu  meanwhile is finished with her postdoc.  She’ll be leaving Stanford for a position at the Gladstone Institute at UCSF in January 2022, but she still intends to work with both Clarke and Assimes in the future.  And who can say what their next set of collaborations may bring?