What is the clinical evidence from this study?

Study design: Observational. Population: persistent atrial fibrillation (n=166). Intervention: Duration of AF < 6 months vs. Duration of AF ≥ 6 months. Primary outcome: Successful electrical cardioversion (OR 2.2, 95% CI 1.1-4.7, p=<0.04).

March 1, 2001Open Access

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

Q: What are the key findings of this study?

Duration of AF <6 months (OR 2.2; 95% CI 1.1-4.7) and weight <80 kg (OR 2.3) independently predicted successful electrical cardioversion in patients with persistent atrial fibrillation.

Key Result

Duration of AF <6 months (OR 2.2; 95% CI 1.1-4.7) and weight <80 kg (OR 2.3) independently predicted successful electrical cardioversion in patients with persistent atrial fibrillation.

Study Design

Type

Observational (n=166)

PICO

Population

166 outpatients with persistent atrial fibrillation for >1 month, scheduled for elective cardioversion and not on class I or III antiarrhythmic drugs, followed for 4 weeks.

Exposure / Comparator

Duration of AF < 6 months vs Duration of AF ≥ 6 months

Primary Outcome

Successful electrical cardioversion — OR 2.2 (1.1-4.7), p=<0.04

Main Result

Odds Ratio: 2.2 (95% CI 1.1–4.7)

p-value: p=<0.04

Abstract

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 electrical cardioversion in patients with persistent AF without concomitant antiarrhythmic drugs of class I and III. 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 Holter electrocardiogram (ECG) before and ECG 4 weeks after cardioversion, were performed in all patients. RESULTS: The mean age of the patients was 68 years (range 45-83) and duration of AF was 5 (1-48) months. Sinus rhythm was established in 124 (75%) patients. 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 identified as independent predictors of successful cardioversion. At 4 weeks after cardioversion, only 46 (37%) of 124 patients maintained sinus rhythm. Independent 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 duration of AF are independent predictors for a successful cardioversion. Short duration of AF, treatment with beta blockers or verapamil/diltiazem, and right atrial area/dimension are independent predictors for maintenance of sinus rhythm.