The effect of sinus rhythm restoration on high-sensitivity C-reactive protein levels and their association with long-term atrial fibrillation recurrence after electrical cardioversion.

OBJECTIVE: Recent studies have shown that high-sensitivity C-reactive protein (hs-CRP) measured before cardioversion (CV) plays a significant role in predicting atrial fibrillation (AF) relapse. The time course of changes in hs-CRP after successful electrical CV remains controversial. The aim of the present study was to assess the prognostic value of pre- and post-CV hs-CRP levels in predicting the long-term risk of AF. Additionally, we evaluated changes in hs-CRP levels over time following a successful CV.

METHODS: This prospective study comprised 216 patients with persistent AF who underwent CV (mean age 51.94 ± 8.07 years; 55.6% men). hs-CRP levels were examined in all patients, and blood samples were taken prior to and 1, 2, 7 and 30 days after CV. AF relapse was determined by 24-hour ambulatory electrocardiogram (ECG) monitoring and 12-lead standard ECG during 12 months of follow-up. We further divided the study population into two groups according to their rhythm at the end of the follow-up period (group A: patients with AF at the end of follow-up; group B: patients with sinus rhythm at the end of the follow-up period).

RESULTS: The AF recurrence rate was 42.2% throughout the 12-month follow-up period. The basal hs-CRP levels were higher in patients with an AF relapse than in those without (1.68 ± 0.57 vs. 1.12 ± 0.53 mg/dl; p < 0.01). The hs-CRP levels were significantly decreased at 30 days in group B, whereas there was no significant decrease in group A (from 1.12 ± 0.53 to 0.69 ± 0.33 mg/dl, p < 0.01, and from 1.68 ± 0.57 to 1.69 ± 0.76 mg/dl, p > 0.05, respectively). By multivariate Cox analysis, the independent predictors of AF relapse time points were the basal and day-2 hs-CRP levels. Receiver operating characteristic curve analysis showed that the cutoff value of hs-CRP on the 2nd day for predicting AF relapse was 1.85 mg/dl, with a sensitivity of 62%, a specificity of 82%, a positive predictive value of 85.7% and a negative predictive value of 81.6%.

CONCLUSION: The hs-CRP levels both prior to and after CV predict the long-term risk of AF relapse. In the present study, hs-CRP levels were significantly decreased in patients who remained in sinus rhythm at the end of the study. In contrast, hs-CRP levels remained high throughout the follow-up in patients with an AF relapse.