Cardiomyopathy mortality among U.S. adults with breast cancer: A 25-year CDC WONDER study.

Abstract

e13139 Background: Cardiovascular disease is an increasingly recognized contributor to mortality among cancer patients. Arrhythmias may represent an underappreciated cause of death in breast cancer, particularly among older individuals and those receiving cardiotoxic therapies. We examined national multiple cause of death data to characterize the burden and demographic patterns of arrhythmia-associated mortality in breast cancer. Methods: This retrospective population-based study used CDC WONDER death certificate data. Deaths with breast cancer (ICD-10 C50) as the underlying cause and arrhythmias (ICD-10 I47–I49) as contributing causes were identified. Age-adjusted mortality rates (AAMRs) per 100,000 population were calculated using the 2000 U.S. standard population. Analyses followed STROBE guidelines and were stratified by age, sex, race/ethnicity, and urbanization. Temporal trends were evaluated descriptively using AAMRs with 95% confidence intervals. Results: Arrhythmia-associated mortality in breast cancer patients remained substantial throughout the study period. AAMRs increased with advancing age, with the highest rates among individuals aged ≥65 years. Racial disparities were observed, with White decedents showing higher absolute AAMRs compared with other groups. Although breast cancer predominantly affects women, sex-stratified analyses showed a notable burden of arrhythmia-related mortality. Mortality rates were higher in metropolitan areas compared with non-metropolitan regions. Temporal analyses indicated persistent arrhythmia-associated mortality over the study period. Conclusions: Arrhythmias are a significant and persistent contributor to mortality among patients with breast cancer. The age-related increase and observed demographic disparities highlight the importance of cardiovascular risk assessment and arrhythmia monitoring in this population. These findings support the integration of cardio-oncology strategies to reduce non-cancer mortality among patients with breast cancer.