Aims: To determine whether the number of circulating endothelial progenitor cells (EPCs) in patients with persistent atrial fibrillation (AF) predicts arrhythmia recurrence after direct current cardioversion (DCCV).
Methods and results: The numbers of circulating CD34+/KDR+ EPCs were determined with flow cytometry in 51 consecutive patients with persistent AF [the mean age: 67 +/- 1.3 years, male (65%)] prior to DCCV and were compared with that of age- and sex-matched controls, and cohorts of patients with coronary artery disease and ischaemic stroke. The AF recurrence rate at 1 year was also determined. The EPCs in patients with persistent AF, patients with coronary artery disease, and patients with ischaemic stroke were significantly lower than that of the age- and sex-matched controls (P < 0.01). One year after successful DCCV, patients with high EPC count (50th to 100th percentile) had a higher recurrence rate of AF when compared with those with low EPC count (less than 50th percentile) (73 vs. 40%, P = 0.02). Cox regression analysis revealed the high EPC count was the only independent predictors for the AF recurrence (HR: 2.29, P = 0.047).
Conclusion: The number of EPCs is reduced in patients with persistent AF and predicts the recurrence of AF after successful DCCV.