Abstract
BACKGROUND: Previous studies conflict on whether seasonal variability exists in atrial fibrillation (AF) admissions, and contemporary studies are lacking. METHODS: We identified admissions for AF or atrial flutter in the Midwest and Northeast regions of the US from the National Inpatient Database for 2016 to 2020, grouped them into the four seasons (spring, summer, fall, winter), and compared the number of admissions. Subgroup analyses were performed stratified to sex, age, race, AF alone, and geographical regions. RESULTS: A total of 955,320 admissions for AF or atrial flutter occurred. The number of admissions was highest during winter (243,990, 25.5% of the total), followed by fall (239,250, 25.0% of the total), summer (236,910, 24.8% of the total), and spring (235,170, 24.6% of the total). The differences were statistically significant (P < 0.001). An increasing trend in the number of admissions was observed from March to February of the next year (P trend <0.001). Admissions were most common in the winter and least common in the spring in subgroups of both sexes, age ≥65 years, Whites, non-Whites, AF alone, Northeast region, and Midwest region. CONCLUSION: Contemporary analysis of a national database demonstrates seasonal variability in the number of admissions for AF, with a slight increase observed during the winter.