Study design and population
Patients hospitalized for AF in the First Affiliated Hospital of
Zhengzhou University from January 2017 to December 2019 were registered
in this retrospective cohort study. Inclusion criteria were as follows:
(1) age >18 years old; (2) history of symptomatic AF for at
least 6 months and documented on electrocardiogram in the previous 1
year. Exclusion criteria were as follows: (1) patients with significant
coronary artery disease verified by coronary angiogram; (2) congenital
heart disease, valvular heart disease and serious dysfunction of kidney
and liver; (3) suffering from infectious diseases and corticosteroid or
nonsteroidal anti-inflammatory drug use in the previous 6 months; (4)
patients with incomplete clinical data and unwilling or unable to commit
to follow up requirements. The study protocol was approved by ethics
committee. Because of the retrospective design of this study, the ethics
committee waived the need of obtaining informed consent from all
participants.