Interleukin-2 serum levels variations in recent onset atrial fibrillation are related with cardioversion outcome

We evaluated the hypothesis that a relationship exists between inflammation and the outcome of pharmaceutical cardioversion with amiodarone in recent onset atrial fibrillation. We studied 86 patients with symptomatic recent onset AF and coexisting hypertension and/or chronic stable coronary artery disease. All study participants underwent evaluation with a standardized protocol including echocardiography, cytokine level measurement [interleukin-2 (IL-2), interleukin-6 (IL-6) and high sensitivity C reactive protein (hsCRP)] on admission and at 48 h, and administration of intravenous amiodarone. By 48 h, 70 patients cardioverted to sinus rhythm. Median serum IL-2 levels on admission were higher in non-cardioverted compared to cardioverted patients (P = 0.002). At 48 h, non-cardioverted had significantly higher IL-6 (P = 0.005) and hsCRP values (P = 0.001) compared to cardioverted. Multivariate logistic regression analysis showed that lower IL-2 admission levels were a powerful independent predictor for successful cardioversion (OR: 0.154, 95% CI: 0.043–0.552, P = 0.004). In patients with hypertension and/or chronic stable coronary artery disease and symptomatic recent onset AF, low serum IL-2 levels on admission are associated with successful cardioversion with amiodarone. This observation highlights the role of inflammation in AF and might have further prognostic and therapeutic implications.