Interleukin 8: Changes in Paroxysmal Atrial Fibrillation

Aims: To study the levels of interleukin-8 (IL-8) in patients with paroxysmal atrial fibrillation (occurred in <48 hours) and track the changes after restoration of sinus rhythm.

Study Design: Prospective.

Place and Duration of Study: The study was conducted in the Intensive Cardiology Department of the First Cardiology Clinic at the University Hospital "St. Marina "- Varna for the period October 2010 – May 2012.

Methodology: We included 51 patients (26 men, 25 women; mean age 59.84±1.60 years) with paroxysmal atrial fibrillation and 52 controls (26 men, 26 women; 59.50±1.46 years) with no history of atrial fibrillation. The two groups matched by age, gender and clinical characteristics. Patients’ plasma concentrations of IL-8 were measured three times: immediately after admission to the ward (baseline values), twenty-four hours and twenty-eight days after rhythm restoration. In the control group the indicator was tested once. IL-8 was measured using an ELISA kit. In all patients the arrhythmia episode was discontinued by the administration of propafenone.

Results: All patients were hospitalized between the second and the twenty-fourth hour after the onset of the arrhythmia, and most frequently in the fifth hour (10 of all 51 patients). Baseline values of IL-8 were increased compared to those of the controls (77.38±3.78 vs 32.18±1.54 pg/mL, p <0.001). Twenty-four hours after restoration of sinus rhythm, IL-8 concentrations were still significantly higher (65.33±3.29 vs 32.18±1.54 pg/mL, p <0.001). On the twenty-eighth day there was no significant difference (28.07±1.68 vs 32.18±1.54 pg/mL, p = 0.07).

Conclusion: Plasma concentrations of IL-8 are significantly elevated in the early hours of the clinical manifestation of paroxysmal atrial fibrillation as well as after the arrhythmia discontinuation. Their restoration occurs slowly over time. The established specific dynamics in IL-8 concentrations suggests a close relationship between paroxysmal atrial fibrillation and inflammation.