Long-term prognostic value of baseline C-reactive protein in predicting recurrence of atrial fibrillation after electrical cardioversion

Background: An increasing body of evidence links atrial fibrillation (AF) to the inflammatory state. It has been suggested that increased C-reactive protein (CRP) levels are associated with greater risk of AF recurrence at short- and mid-term. Objective: We sought to investigate the association between CRP and long-term risk of AF recurrence. Methods: This was a prospective observational study. We investigated the association between baseline CRP levels and recurrence of AF over a 3-year follow-up period after successful electrical cardioversion (EC). A total of 60 patients were studied (mean age: 68.4 +/- 7.2 years, 60% men). All patients were receiving amiodarone for sinus rhythm maintenance. We further divided the study population into three tertiles according to the values of baseline CRP (tertile 1: < 0.43 mg/dL; tertile 2: 0.43-0.8 mg/dL; tertile 3: > 0.8 mg/dL). Results: Overall, 75% of patients relapsed into AF during the 3-year study period. AF recurrence was significantly lower in the 1st CRP tertile group (P = 0.039). The Kaplan-Meier survival analysis showed that the rate of AF recurrence was significantly lower in the lowest CRP tertile (log rank; P < 0.001). In a multivariable Cox regression model adjusted for other potential covariates, only CRP (upper two tertiles) was an independent predictor of AF recurrence (heart rate: 6.3, 95% confidence interval: 3.1-12.7, P < 0.001). Conclusions: Our findings suggest that baseline CRP levels before EC have an independent prognostic value in predicting the long-term risk of AF recurrence.