Predicting atrial fibrillation recurrence with circulating inflammatory markers in patients in sinus rhythm at high risk for atrial fibrillation: Data from the GISSI atrial fibrillation trial

Background: Inflammation may play a significant role in the pathogenesis of atrial fibrillation (AF). Objectives: To examine the roles of three systemic inflammatory markers in predicting recurrent AF. Methods: The association between the plasma concentrations of high-sensitivity C reactive protein (hsCRP), interleukin-6 (IL-6) and pentraxin-3 (PTX3) with echocardiographic parameters and with the time to first recurrence of AF was tested in 382 patients with a history of AF but in sinus rhythm at randomisation, enrolled in the GISSI-AF biohumoral study. Results: Baseline PTX3 was related to left atrial, but not to left ventricular chamber volume. During one year of follow-up, 204 patients (53.1%) had a recurrent AF. There were no significant differences in baseline median [Q1-Q3] plasma concentrations of IL-6, hsCRP and PTX3 among patients with (2.11 [1.47-3.74] pg/ml, 3.30 [1.40-6.80] mg/l and 4.66 [3.27-6.97] ng/ml, respectively) or without recurrent AF (2.09 [1.37-2.90] pg/ml, p=0.182; 3.00 [1.10-6.20] mg/l, p=0.333; 5.09 [3.22-7.98] ng/ml, p=0.637). At 6 and 12 months follow-up, AF patients had significantly higher concentrations of IL-6 and PTX3 than those in sinus rhythm, and those with most recent episodes of AF had higher hsCRP. Baseline levels of IL-6, hsCRP or PTX3 were not significantly associated with a higher risk of recurrence of AF. Conclusion: In patients with a history of AF, but without significant left ventricular dysfunction or heart failure, inflammatory biomarkers may be raised but are, at best, weak predictors of the risk for first recurrence of AF.