DISCUSSION
Our analysis reveals a significant and sustained increase in cancer- and AF-related mortality among U.S. adults over the past two decades. While similar trends were observed across both sexes and racial groups, significant geographic and demographic disparities persist. NH White Americans exhibited the highest AAMRs compared to other racial groups, and men had higher AAMRs than women. Although cancer-related mortality has been on the decline since the 1990s, the upward trajectory in AF-related mortality has been a major contributor to the overall rise in mortality rates.9
The observed increase in mortality can be attributed to two primary factors: (1) changes in the prevalence of underlying diseases, or (2) fluctuations in case fatality rates. Recent advancements in diagnostic and therapeutic strategies for both cancer and AF have likely contributed to a reduction in overall case fatality rates. The introduction of direct oral anticoagulants (DOACs) in 2010, for example, has been shown to reduce all-cause mortality for AF by 10% compared to warfarin.10 This suggests that the recent rise in AAMRs observed in our study is more likely driven by the growing prevalence of AF and cancer cases, rather than an increase in case fatality rates.
This phenomenon also helps explain the racial disparities observed in our findings. Previous research has identified that Black adults face a disproportionate burden of AF risk factors. Furthermore, Black individuals are less likely to receive DOACs compared to their White counterparts, more often receive rate control strategies rather than the preferred rhythm control, and are underrepresented in major AF clinical trials.11 Interestingly, the lower prevalence of AF among Black individuals may partly account for the lower AAMRs observed within this group.
Our analysis is subject to several limitations. The reliance on ICD codes and death certificates may result in misclassification of the cause of death, potentially compromising the accuracy of the findings. Additionally, the dataset does not include critical data on laboratory parameters, echocardiographic findings, medical therapies, and socioeconomic determinants of health—factors that could substantially influence mortality rates.