Trends in ischemic heart disease mortality among older adults with co-existing colorectal cancer in the US (1999-2023): a 25-Year retrospective study.

INTRODUCTION: Ischemic heart disease (IHD) continues to be the primary cause of death among older adults in the United States (U.S.), while colorectal cancer (CRC), being the 3rd most common cancer, contributes to increased mortality when co-occurs with IHD. This study examines national trends in IHD mortality from 1999 to 2023 among older adults with co-existing CRC. METHODS: The study retrospectively analyzed death certificates from the CDC's Wide-ranging ONline Data for Epidemiologic Research (WONDER) database, including older adults (aged ≥ 65 years) who listed IHD as the underlying cause of death while CRC was a contributing cause. Crude and age-adjusted mortality rates (AAMRs) per 100,000 individuals, as well as the annual percent change (APC) in AAMRs with a 95% confidence interval, were obtained. RESULTS: A total of 43,417 deaths were attributed to IHD among patients with coexisting CRC. AAMR declined significantly throughout the study, being more prominent from 2003 to 2016 (APC - 8.65; p < 0.05). Males (6.3) had doubled the AAMR that of females (3.1). Non-Hispanic (NH) African Americans represented the highest AAMR (4.5), followed by other races/ethnicities. Regionally, peak AAMR was observed in the northeast (5.7) and non-metropolitan areas (4.7). CONCLUSIONS: A substantial (75%) reduction in AAMR was observed from 1999 to 2023. However, disparities across different demographical and geographical highlight the need for targeted interventions to lower IHD burned among patients with co-existing CRC.