Heart, Lung and Circulation

Inclusion of Under-Represented Racial and Ethnic Groups in Cardiovascular Clinical Trials


      Non-White racial and ethnic groups have been traditionally under-represented for decades in the field of cardiology, specifically in cardiovascular research studies. This underrepresentation has occurred despite the fact that these racial and ethnic groups have been shown to be at increased risk of cardiovascular disease (CVD).


      To assess the trend of representation in mainstream landmark cardiovascular trials, we performed a review of major cardiovascular trials published between 1986 and 2019. Mainstream landmark trials were selected as classified by established cardiology standards. The reported numbers of racial and ethnic participants were assessed within these categorised cardiovascular trials over a continuous time period.


      A total of 1,138,683 patients were assessed from 153 randomised clinical trials. Of these trials, only 56% (n=86) reported information about race. Of note, 99% (n=152) of these trials reported gender. About three-quarters of the trials (77%) were undertaken at least partly in the United States (US). Our results show that the percentage of non-White participants in clinical trials was not significantly different over time (p=0.85), suggesting no significant improvement in non-White racial/ethnic representation. Further analysis of only the US inclusive trials (n=20) also showed no significant improvement in representation (p=0.38).


      Only about half of all major cardiovascular landmark trials reported any racial or ethnic information, despite more recent calls over the last 5–10 years for diversity and representation in cardiovascular research studies. Additionally, no significant improvement in inclusion of traditionally under-represented racial and ethnic groups (UREGs) in these trials has occurred over time. Our analysis shows that there is still major work to be done to foster better representation and evaluation of the UREG population in cardiovascular trials.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Heart, Lung and Circulation
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Virani S.S.
        • Alonso A.
        • Aparicio H.J.
        • Benjamin E.J.
        • Bittencourt M.S.
        • Callaway C.W.
        • et al.
        American Heart Association Council on Epidemiology and Prevention Statistics Committee and Stroke Statistics Subcommittee. Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association.
        Circulation. 2021 Feb 23; 143: e254-e743
        • Ghosal S.
        • Mukherjee J.J.
        • Seshadri Krishna K.G.
        • Debasish Maji
        • Tripathi K.
        Consensus Statement on Implication of Landmark Trials in Diabetes.
        J Assoc Physicians India. 2016; 64: 7-12
      1. Key cardiology trials in evidence-based medicine. [accessed 9.19].

      2. Cardiology Clinical Trials: Cardiology Clinical Trials |
      3. List of landmark papers/Cardiology. WikiJournalClub.
        • Steinberg B.A.
        • Cannon C.P.
        Evidence-Based Cardiology.
        Fourth Edition. Wolters Kluwer, Philadelphia, PA2016
        • Bhatt D.P.
        Top Clinical Trials and Journal Scans.
        JACC, 2018
        • Arnett D.K.
        • Blumenthal R.S.
        • Albert M.A.
        • Buroker A.B.
        • Goldberger Z.D.
        • Hahn E.J.
        • et al.
        2019 ACC/AHA Guideline on the primary prevention of cardiovascular disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.
        J Am Coll Cardiol. 2019; 74 (Erratum in: J Am Coll Cardiol. 2019;74(10):1429-1430): e177-e232
        • Zhang T.
        • Tsang W.
        • Wijeysundera H.C.
        • Ko D.T.
        Reporting and representation of ethnic minorities in cardiovascular trials: a systematic review.
        Am Heart J. 2013; 166: 52-57
        • Berger J.S.
        • Melloni C.
        • Wang T.
        • Dolor R.J.
        • Frazier C.G.
        • Samad Z.
        • et al.
        Reporting and representation of race/ethnicity in published randomized trials.
        Am Heart J. 2009; 158: 742-747
      4. U.S. Census Bureau Quick Facts: United States. Census Bureau Quick Facts.
        • Rosamond W.D.
        • Chambless L.E.
        • Heiss G.
        • Mosley T.H.
        • Coresh J.
        • Whitsel E.
        • et al.
        Twenty-two-year trends in incidence of myocardial infarction, coronary heart disease mortality, and case fatality in 4 US communities, 1987-2008..
        Circulation. 2012; 125: 1848-1857
        • Vaccarino V.
        • Abramson J.L.
        • Veledar E.
        • Weintraub W.S.
        Sex differences in hospital mortality after coronary artery bypass surgery: evidence for a higher mortality in younger women.
        Circulation. 2002; 105: 1176-1181
        • Mensah G.A.
        • Mokdad A.H.
        • Ford E.S.
        • Greenlund K.J.
        • Croft J.B.
        State of disparities in cardiovascular health in the United States.
        Circulation. 2005; 111: 1233-1241
        • Mensah G.A.
        Eliminating disparities in cardiovascular health: six strategic imperatives and a framework for action.
        Circulation. 2005; 111: 1332-1336
      5. Califf RM. 2016: The year of diversity in clinical trials. MassDevice. Published January 27, 2016. [accessed 1.19].

        • Oh S.S.
        • Galanter J.
        • Thakur N.
        • Pino-Yanes M.
        • Barcelo N.E.
        • White M.J.
        • et al.
        Diversity in clinical and biomedical research: a promise yet to be fulfilled.
        PLoS Med. 2015; 12e1001918
      6. Food and Drug Administration. Enhancing the Diversity of Clinical Trial Populations - Eligibility Criteria, Enrollment Practices, and Trial Designs Guidance for Industry. Published June 2019. [accessed 8.19].

        • Heller C.
        • Balls-Berry J.E.
        • Nery J.D.
        • Erwin P.J.
        • Littleton D.
        • Kim M.
        • et al.
        Strategies addressing barriers to clinical trial enrollment of underrepresented populations: a systematic review.
        Contemp Clin Trials. 2014; 39: 169-182
        • Bole K.
        Diversity in medical research is a long way off, study shows. Diversity in medical research is a long way off, study shows | UC San Francisco.
        • Fogacci F.
        • Gori D.
        • Cicero A.F.G.
        Representativity of women and racial/ethnic minorities in randomized clinical trials on bempedoic acid: positive efforts and lacking data.
        Eur J Intern Med. 2022; 96: 122-123
        • Fogacci F.
        • Borghi C.
        • Di Micoli A.
        • Degli Esposti D.
        • Cicero A.F.G.
        Inequalities in enrollment of women and racial minorities in trials testing uric acid lowering drugs.
        Nutr Metab Cardiovasc Dis. 2021; 31: 3305-3313