Abstract 17468: Is There an Association Between Number of External Cardioversions and Mortality_Insights from the AFFIRM Study
Background: Internal and external electrical cardioversions (CV) effectively terminate arrhythmias. While the amount of electrical current used for CV is considered to be ”safe,” recent data suggest a possible increase in mortality associated with internal CV in patients with implantable cardiac defibrillators. However, little is known about the association between external CV and mortality.
Purpose: To assess the safety of repeated elective external CV among patients with atrial fibrillation participating in a large prospective study.
Methods: We analyzed the 4,060 patients who participated in the AFFIRM trial. Patients were divided into five groups based on the total number of external CV episodes (zero, one, two, three, ≥ four) before randomization and during the study period. Associations between CV and death during follow-up (mean 3.5 years) were assessed for statistical significance, both overall and based on ejection fraction (EF) > 45% and ≤ 45%. In addition, a multivariate Cox model was used to assess the relations between death and several variables including cumulative number of external CV episodes and EF.
Results: (See Table 1)The number of CV episodes was not significantly associated with death during follow-up (p=0.19). Among those with EF > 45%, there was a trend toward greater survival with more CV episodes (3% mortality with ≥ 2, 11% with 1 and 13% with 0; p=0.10). The Cox model revealed a similar trend (p=0.07) and demonstrated that coronary artery bypass graft (CABG), myocardial infarction (MI) and digoxin were associated with an increased risk of death (estimated hazard ratios, respectively: 1.68, 1.50, and 1.24).
Conclusion: In the AFFIRM study, there was no significant association between the number of external CV episodes and mortality. However, CABG, MI, and digoxin were independently associated with an increased risk of death.
- Arrhythmias, treatment of
- Atrial fibrillation
- Ejection fraction
- Atrial arrhythmias
- Atrial defibrillation
- © 2010 by American Heart Association, Inc.