Abstract Body (Do not enter title and authors here): Introduction
Underrepresentation in clinical trials remains a significant obstacle to achieving equitable healthcare outcomes. In an effort to promote transparency and inclusivity, Congress enacted the Final Rule for Clinical Trials Registration and Results Information Submission (42 CFR Part 11) in January 2017, mandating the reporting of race and ethnicity data on ClinicalTrials.gov. This study examines demographic trends in enrollment for transthyretin amyloid cardiomyopathy (ATTR-CM) clinical trials.

Hypothesis
We hypothesize that a significant difference exists between the demographic composition of patients diagnosed with ATTR-CM and those enrolled in U.S.-based clinical trials.

Methods
A systematic review of ClinicalTrials.gov was conducted using the search terms “Transthyretin Amyloid Cardiomyopathy,” “Cardiac Amyloidosis,” and “Amyloidosis Cardiac.” Inclusion criteria were U.S.-based studies completed since 2018 with publicly available results. Extracted demographic data included sex, age, and race/ethnicity. An enrollment fraction (EF), the ratio of clinical trial participants to the estimated U.S. disease prevalence, was calculated for gender and race using data from the Cardiac Amyloidosis Registry Study (CARS). Due to limited data, EF calculations were only feasible for participants identifying as White or Black. Statistical analyses were performed using Python.

Results
Of 264 identified trials, 17 met the inclusion criteria, 11,786 participants (8,578 males and 3,208 females; male-to-female ratio approximately 3:1). The average participant age was 61 years. Racial and ethnic composition was as follows: White 54%, Black 6.2%, Asian 5.2%, Latino 2.1%, Native Hawaiian or Pacific Islander 0.01%, Native American 0.02%, and Unknown 27.4%. Chi-squared analysis revealed that the EF for White participants was significantly higher than for Black participants (5.85 vs. 0.62; p < 0.05). Male participants also had a higher EF than females (0.12 vs. 0.05; p < 0.05).

Conclusion
Despite the 2017 Final Rule, ATTR-CM clinical trials continue to show significant racial and gender disparities. This limits the generalizability of findings and equitable treatment access. Future strategies should prioritize culturally sensitive recruitment, community engagement, and stronger policy enforcement to promote inclusive trial designs.