Factors predicting success rate and recurrence of atrial fibrillation after first electrical cardioversion in patients with persistent atrial fibrillation

Background: The recurrence rate of atrial fibrillation (AF) after elective cardioversion is high. Hypothesis: The study aimed to identify clinical predictors for successful electrical cardioversion and maintenance of sinus rhythm after a first elec trical cardioversion in patients with persistent AF without concomitant ant iarrhythmic drugs of class I and LII. Methods: Consecutive outpatients (n = 166) with persistent AF for > 1 month , scheduled for elective cardioversion, were prospectively included in the study. A clinical investigation, echocardiographic assay, and Kelter electr ocardiogram (ECG) before and ECG 4 weeks after cardioversion, were performe d in all patients. Results: The mean age of the patients was 68 years (range 45-83) and durati on of AF was 5 (1-48) months. Sinus rhythm was established in 124 (75%) pat ients. In multivariate analysis, only duration of AF < 6 months (p < 0.04, odds ratio [OR] 2.2, 95% confidence interval [CI] 1.1 to 4.7) and patients weight (p <0.03, OR 2.3, 95% CI 1.1 to 4.8 for weight < 80 kg) were identif ied as independent predictors of successful cardioversion. At 4 weeks after cardioversion, only 46 (37%) of 124 patients maintained sinus rhythm. Inde pendent factors for maintenance of sinus rhythm, in multivariate analysis, were AF <3 months (p<0.04, OR 2.5, 95% CI 1.1 to 5.6), treatment with beta blockers (p < 0.00001, OR 7.0, 95% CI 3.0 to 16.3) or verapamil/diltiazem ( p<0.04, OR 3.6, 95% CI 1.1 to 12.1), and right atrial dimension < 37 mm (p < 0.02, OR 5.9, 95% CI 1.4 to 25.4). Conclusions: In patients with persistent AF, the patient's weight and the d uration of AF are independent predictors for a successful cardioversion. Sh ort duration of AF, treatment with beta blockers or verapamil/diltiazem, an d right atrial area/dimension are independent predictors for maintenance of sinus rhythm.