Trends in mortality involving atrial fibrillation/flutter and renal failure in the United States, 1999-2023: A nationwide multiple-cause-of-death analysis

Atrial fibrillation (AF)/flutter and renal dysfunction commonly coexist and are associated with substantial cardiovascular and thromboembolic risk. Despite this clinical overlap, national mortality patterns among individuals whose death certificates record both conditions have not been well characterized over an extended period. We examined changes over time in deaths documenting both AF/flutter and renal failure and assessed whether these patterns differed across demographic and geographic groups among U.S. adults aged ≥ 45 years from 1999 to 2023. We queried the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research Multiple-Cause-of-Death database for death certificates of U.S. adults aged ≥ 45 years in which AF/flutter (International Classification of Diseases, Tenth Revision I48) and renal failure (N17-N19) were both recorded. Either diagnosis could appear as the underlying or a contributing cause of death. Mortality rates were age-standardized to the 2000 U.S. population and expressed per 100,000 persons. Joinpoint regression was used to evaluate changes in annual age-adjusted mortality rates and to estimate annual percentage changes (APCs). The study included 392,927 death certificates meeting these criteria. The age-adjusted mortality rate increased from 6.3 per 100,000 in 1999 to 20.6 per 100,000 in 2023. Significant upward trends occurred during 1999 to 2012 (APC, 6.21%) and 2015 to 2023 (APC, 9.62%). Rates were higher among men than women throughout the study period. In 2023, the age-adjusted mortality rate was 22.55 per 100,000 among non-Hispanic White individuals, 19.91 among non-Hispanic Black or African American individuals, 14.31 among non-Hispanic American Indian or Alaska Native individuals, 11.75 among Hispanic or Latino individuals, and 10.28 among non-Hispanic Asian or Pacific Islander individuals. The age-adjusted mortality rate for deaths documenting both AF/flutter and renal failure increased markedly among U.S. adults aged ≥ 45 years between 1999 and 2023. The magnitude of this mortality pattern differed by sex, race/ethnicity, and geographic location. Because the analysis is based on diagnoses documented on death certificates, the findings reflect population-level co-documentation of the 2 conditions and do not establish that either condition, alone or in combination, directly caused death. Individual-level studies are needed to determine the clinical and healthcare factors associated with these trends.