Vinson DR, et al. - This work sought to ascertain patient characteristics, ibutilide administration patterns, cardioversion rates, and adverse outcomes in the community emergency department (ED) setting. In addition, researchers looked for potential predictors of cardioversion success. In this community ED setting, the effectiveness and safety of ibutilide were consistent with clinical trial results despite less stringent patient selection criteria.

Methods

• From January 2009 to June 2015, a retrospective cohort of adults who received ibutilide in 21 community EDs was used to gather demographic and clinical variables from electronic health records and structured manual chart review.
• For potential predictors of cardioversion, researchers calculated rates of cardioversion and frequency of ventricular tachycardia within 4 hours and estimated adjusted odds ratios (aOR) in a multivariate regression model.

Results

• 361 patients were included [median age: 61 years (interquartile range 53 to 71 years)]; most had recent-onset atrial fibrillation and flutter (98.1%).
• A history of heart failure was evident in five percent of the cohort.
• In 29.4% of patients, the initial QTc interval was prolonged (>480 ms).
• 3.1% patients were hypokalemic (<3.5 mEq/L).
• In this study, the mean ibutilide dose was 1.5 mg (SD 0.5 mg) and the rate of ibutilide-related cardioversion within 4 hours was 54.8% (95% confidence interval [CI] 49.6% to 60.1%), 50.5% for atrial fibrillation and 75.0% for atrial flutter.
• During the second ibutilide infusion, two patients experienced ventricular tachycardia (0.6%).
• Age (in decades) (aOR 1.3; 95% CI 1.1 to 1.5), atrial flutter (versus atrial fibrillation) (aOR 2.7; 95% CI 1.4 to 5.1), and no history of atrial fibrillation and flutter (aOR 2.0; 95% CI 1.2 to 3.1) seemed related with cardioversion.