Temporal Trends for Patients Hospitalized With Atrial Fibrillation in the United States: An Analysis From the National Inpatient Sample (NIS) Database 2011-2018

Background: Atrial fibrillation (AF) has historically been a growing burden on the global public health system. Previously, literature on the trends associated with AF-related hospitalizations has been published. However, there seems to be a gap in up-to-date information, notably within the last decade. Purpose: This study aims to investigate the trends, outcomes, and factors associated with AF hospitalization and the continued impact of AF on the United States health system. Methods: Patient data were collected from the years 2011 to 2018 from the National Inpatient Sample (NIS) database using the International Classification of Diseases (ICD)-9 and ICD-10 codes. We selected patients hospitalized with a diagnosis of AF. Descriptive statistics, statistical analysis, and Mann-Whitney U testing were employed to compare continuous dichotomous variables. After respective adjustments, multivariate hierarchical logistic regression was used to establish mortality rates, length of stay (LOS), and hospital charges. Results: The study included 509,305 patients hospitalized with a primary diagnosis of unspecified AF. The mean age of patients hospitalized with AF was 71 years. AF hospitalizations were slightly higher in women as compared to men (51.7% vs. 48.2%). The predominant race involved was Caucasians at 77.9% followed by African Americans and Hispanics at 7.4% and 5.4%, respectively. The three most frequent coexisting conditions noted were hypertension (69.9%), diabetes mellitus (24.3%), and chronic obstructive pulmonary disease (16.4%). Medicare/Medicaid was the primary payer associated with the majority of AF hospitalizations at 72.6%. Overall in-hospital mortality associated with AF hospitalizations was 0.96%. Comorbid conditions conferring the highest mortality risks included coagulopathies (644%) and cerebral vascular accidents (597%). Mean LOS was found to be 3.35 days. Hospitalization charges increased year-over-year and correlated with an increase in the national burden of cost for these patients of $3.6 billion. Conclusions: Our study investigates the national trends surrounding AF hospitalizations. Overall in-hospital mortality rates appear to be stable as compared to prior years and past literature. Comorbid conditions conferring significantly higher mortality rates included coagulopathies, cerebral vascular accidents, acute kidney injury, and end-stage renal disease. Additionally, suboptimal insurance status was also associated with increased mortality risk. The cost of hospitalization in AF patients has increased steadily, conferring a $3.6 billion burden on the US healthcare system.