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.