To Örebro University

Background: Epidemiological evidence regarding the link between cancer and atrial fibrillation (AF) are limited and outcomes of metastatic cancer comorbid with AF need to be elucidated.

Objective: This study aims to evaluate the prevalence, temporal trends, and outcomes of AF in hospitalized metastatic cancer patients.

Methods: The National Inpatient Sample (NIS) database was used to identify adult patients with metastatic tumors from 2003 to 2014. We analyzed the trends in AF prevalence, in-hospital mortality, total cost, length of stay (LOS), and comorbidities pertaining to metastatic cancer. Multivariable-adjusted models were used to evaluate the association of AF with clinical factors, in-hospital mortality, total cost, and LOS.

Results: Among 2,478,598 patients with metastatic cancer, 8.74% (216,737) were diagnosed with AF. The proportion of comorbid AF increased from 8.28% in 2003 to 10.06% in 2014 (p < 0.0001). Older age, white race, male, Medicare, higher income, larger hospital bed size, and urban teaching hospital were associated with higher AF occurrence. Among primary tumor sites, lung cancer experienced the highest odds of AF compared to other cancers. Patients with metastasis to lymph node and respiratory organ had higher odds of AF. In metastatic cancer, AF was associated with higher in-hospital mortality (odds ratio: 1.48; 95% confidence interval: 1.43-1.54), 18% longer LOS, and 19% higher cost.

Conclusions: AF prevalence in metastatic cancer continues to increase from 2003 to 2014. AF is linked to poorer prognosis and higher healthcare resource utilization. As the population ages, optimal preventive and treatment management strategies are needed for metastatic cancer comorbid with AF.