The association between influenza infection, vaccination, and atrial fibrillation: A nationwide case-control study

Abstract

Background: Influenza infection could activate systemic inflammatory responses and increase the sympathetic tone that plays an important role in the pathogenesis of atrial fibrillation (AF).

Objectives: The goal of the present study was to investigate whether influenza infection was a risk factor for AF. We also aimed to study whether influenza vaccination could decrease the risk of AF.

Methods: From 2000 to 2010, a total of 11,374 patients with newly diagnosed AF were identified from the Taiwan National Health Insurance Research Database. On the same date of enrollment, 4 control patients (without AF) with matched age and sex were selected to be the control group for each study patient. The relationship between AF and influenza infection or vaccination 1 year before the enrollment was analyzed.

Results: Compared with patients without influenza infection or vaccination (reference group; n = 38,353), patients with influenza infection without vaccination (n = 1369) were associated with a significantly higher risk of AF with an odds ratio of 1.182 (P = .032) after adjustment for baseline differences. The risk of AF was lower in patients receiving influenza vaccination without influenza infection (n = 16,452) with an odds ratio of 0.881 (P < .001). In patients who have received influenza vaccination and experienced influenza infection (n = 696), the risk of AF was similar to that in the reference group (odds ratio 1.136; P = .214). The lower risk of AF with vaccination was consistently observed in subgroup analyses.

Conclusion: Influenza infection was significantly associated with the development of AF, with an 18% increase in the risk, which could be reduced through influenza vaccination.

Keywords: Atrial fibrillation; Influenza infection; Vaccination.