Abstract Body (Do not enter title and authors here): Background: The remarkable decline in the overall prevalence and mortality rates of cardiovascular diseases (CVD) in the United States (US) over the past few decades has not been consistent across all age groups, sexes, races, and types of cardiovascular diseases. Heart disease (HD) and heart failure (HF) still pose a significant burden to the healthcare system.

Objectives: This study sought to describe the age, sex and racial disparities in the trends in mortality rates for these two outcomes in the US over the past two decades.

Methods: This was an ecological study with trend analysis of the mortality from heart disease and heart failure in the US between 2000 and 2020. Data on CVD was obtained from the National Centers for Disease Control and Prevention (CDC) surveillance databases and analyzed. Binomial regression models were used to evaluate trends in outcomes. Statistical significance was considered for p-values < 0.05.

Results: There was a significant decrease in the age-standardized mortality for HD over the past two decades (from 343.5 per 100,000 cases to 215.1 per 100,000 cases (p<0.001)). Mortality rates were significantly higher in males (p<0.001, R2 = 0.92), non-Hispanic blacks (p<0.001) and non-Hispanic whites (p<0.001) compared to Hispanics, (R2 = 0.94) and in adults aged 65+ (p<0.001) and 75+ (p<0.001) (R2 = 0.98). There was no significant decrease in the age-standardized mortality for HF (from 26.9 per 100,000 cases to 25.7 per 100,000 cases (p=0.706)) due to a reversal in the trend after 2011. Though the rates were significantly lower in males overall (p=0.001, R2 = 0.27), these rates became higher in males and in non-Hispanic Blacks compared to non-Hispanic Whites beyond 2016. Mortality rates due to HF were highest in the 65+ and 75+ age groups.

Conclusions: This study on national trends in heart disease and heart failure across age groups, sexes and races over the past two decades confirmed a significant reduction in heart disease mortality rates over this period, but with persistent disparities between males and females, non-Hispanic Blacks and other races and the older age groups. This study also highlights important reversals of heart failure mortality rates trends in more recent years in males and females, and non-Hispanic Blacks and Whites, the reasons for which are amenable to further research.