Introduction: There is severe underrepresentation of racial and ethnic groups in many cardiovascular clinical trials. Early-phase clinical trials examine the action and safety limits of treatment and thus, underrepresentation may have particularly deleterious effects.Hypothesis: Ethnic and Racial groups are underrepresented in early-phase trials.Methods: Using the clinicaltrials.gov database, we examined the racial and ethnic representation in Phases 1, 2, 3, and 4 in completed heart failure clinical trials (N=89) with reported results from 2016-2021. We examined the proportion of trials with a representation equal or greater than % U.S. Census population (12% for African American (AA), 19% for Hispanic/Latino (HL), and 7% for Asian (AN)) and determined the median trial representation percentage for AA, HL, and AN groups. Using Chi-square analysis we compared the percent representation across the trial phases.Results: We found that 49%, 91%, and 87% Phase 1 and 2 trials have a lower AA, HL, and AN representation, respectively, compared to that in the U.S. Population (Table 1). HL and AN representation in Phase 1 and 2 trials is particularly low. There is significant variation in AA, HL, and AN representation across all trial phases(p<0.001).Conclusions: Significant underrepresentation of racial and ethnic groups persist in contemporary Phase 1 and 2 trials. Efforts to create a standard for collecting and reporting demographics along with increasing racial and ethnic group representation closer to US population may reduce the risk of future adverse events.