Analysis of clinical risk factors of failed electrical cardioversion in patients with persistent atrial fibrillation or atrial flutter

Abstract

Abstract Background Although rhythm control could be the best for symptomatic atrial fibrillation (AF), some patients fail to achieve sinus rhythm (SR). This study aimed to identify clinical risk factors of failed electrical cardioversion (ECV). Methods A total of 248 patients who received ECV for persistent AF or atrial flutter (AFL) were retrospectively reviewed. Patients were divided into three groups: Group 1 maintained SR for > 1 year, group 2 maintained SR ≤ 1 year after ECV, and group 3 failed ECV. SR maintenance was assessed using regular electrocardiography or Holter monitoring. Results Patients were divided into group 1 (73, 29%), group 2 (146, 59%), and group 3 (29, 12%). The mean age of patients was 60 ± 10 years, and 197 (79%) were male. Age, sex, and baseline characteristics were similar among groups. However, increased cardiac size, digoxin use, heart failure (HF), and decreased left ventricular ejection fraction (LVEF) were more common in group 3. Univariate analysis of clinical risk factors for failed ECV was increased cardiac size [hazard ratio (HR) 2.14 (95% confidence interval [CI], 1.06–4.34, p = 0.030)], digoxin use [HR 2.66 (95% CI, 1.15–6.14), p = 0.027], HF [HR 2.60 (95% CI, 1.32–5.09), p = 0.005], LVEF < 40% [HR 3.45 (95% CI, 1.00–11.85), p = 0.038], and decreased LVEF [HR 2.49 (95% CI, 1.18–5.25), p = 0.012]. Among them, HF showed clinical significance only by multivariate analysis [HR 3.01 (95% CI, 1.13–7.99), p = 0.027]. Conclusions Increased cardiac size, digoxin use, HF, LVEF < 40%, and decreased LVEF were related to failed ECV for persistent AF or AFL. Among these, HF was the most important risk factor. Further multi-center studies including greater number of participants are planned.