Duration of warfarin sodium therapy prior to electrical cardioversion of atrial fibrillation.

Abstract

OBJECTIVES: To evaluate the duration of anticoagulation treatment with warfarin sodium before elective DC-cardioversion and to identify clinical variables predicting short-term versus long-term waiting times. DESIGN: Retrospective. SUBJECTS: Patients with a known start date for warfarin sodium, a known duration of atrial fibrillation (AF) and who underwent DC-cardioversion were included. MAIN OUTCOME MEASURES: Duration of treatment with warfarin sodium prior to DC-cardioversion. METHODS: The hospital records of 288 consecutive patients with AF scheduled for elective cardioversion at two hospitals in Stockholm were reviewed. Only patients with a known start date for warfarin sodium and known duration of AF were included in the study. RESULTS: The median age was 70 (26-85) years and the duration of AF at time of cardioversion were 18 weeks (5-273) weeks. The median treatment duration prior to cardioversion with warfarin sodium was 12 weeks. Sinus rhythm was established in 224 (78%) patients of which 90 (40%) remained in sinus rhythm 1 month after cardioversion. In multivariate analysis, the only independent predictor of short waiting times for cardioversion (8 vs. 15 weeks) was if a cardiologist instituted the treatment with warfarin sodium (P < 0.001, 95% CI 5.0-9.0). CONCLUSION: The average waiting time from start of warfarin sodium treatment to elective cardioversion exceeds by far the recommended 3-4 weeks on therapeutic international normalized ratio (INR). In order to minimize the time period until cardioversion significant changes in the out-of-hospital care logistics has to be undertaken.