Cancer-associated bradyarrhythmias and inpatient deterioration in U.S. hospitalizations.

Abstract

e23107 Background: Cardiac rhythm disturbances in oncology are most often studied in atrial fibrillation and tachyarrhythmias. Bradyarrhythmias may reflect autonomic dysfunction, conduction system toxicity, or paraneoplastic effects, yet their inpatient burden and prognostic significance in hospitalized cancer populations remain poorly characterized. This study evaluated whether bradyarrhythmias identify a high-risk inpatient phenotype among cancer hospitalizations. Methods: We performed a serial cross-sectional analysis of adult hospitalizations with a principal diagnosis of malignancy in the 2018 to 2022 Healthcare Cost and Utilization Project National Inpatient Sample using discharge-level survey weighting. Bradyarrhythmias were identified using any-diagnosis ICD-10-CM codes for atrioventricular conduction disease, sick sinus syndrome, or bradycardia. Outcomes included in-hospital mortality, shock, intensive care unit utilization, and permanent pacemaker implantation. National estimates accounted for survey stratification and clustering. Survey-weighted multivariable logistic regression adjusted for demographics, cancer type, heart failure, sepsis, admission characteristics, payer, income quartile, hospital teaching status, and geographic region. Sensitivity analyses excluded hospitalizations with heart failure or sepsis. Results: Among an estimated 4.81 million cancer hospitalizations nationally, bradyarrhythmias occurred in 3.9 percent. Hospitalizations with bradyarrhythmias had higher in-hospital mortality (5.9 percent vs 4.3 percent), shock (2.8 percent vs 1.3 percent), and intensive care unit utilization (7.0 percent vs 3.4 percent). Permanent pacemaker implantation was uncommon overall but more frequent among bradyarrhythmia admissions (4.0 percent vs 2.9 percent). After adjustment, bradyarrhythmias remained independently associated with in-hospital mortality (adjusted odds ratio 1.11, 95% CI 1.05 to 1.17), shock (adjusted odds ratio 1.71, 95% CI 1.60 to 1.84), intensive care unit utilization (adjusted odds ratio 1.92, 95% CI 1.83 to 2.01), and permanent pacemaker implantation (adjusted odds ratio 1.40, 95% CI 1.32 to 1.49). Associations persisted after exclusion of hospitalizations with heart failure or sepsis. Conclusions: Bradyarrhythmias can occur during cancer hospitalizations and identify a high-risk inpatient phenotype characterized by shock, critical care utilization, mortality, and need for permanent pacing. These findings can guide further research to evaluate bradycardia and its complications as potential cancer related outcomes.