Conversion efficacy of intravenous ibutilide compared with intravenous amiodarone in patients with recent-onset atrial fibrillation and atrial flutter

Aim: The aim of our study was to compare the efficacy and safety of ibutilide and amiodarone (intravenously) in converting recent-onset atria] fibrillation (AF) and atrial flutter (Af) to sinus rhythm (SR). Methods: The study was prospective, randomized and included 152 (103 men and 49 women) consecutive patients with AF or Af of 3-48 h duration. lbutilide is a selective class III antiarrhythmic agent which when administered intravenously can terminate AF and Af. Armodarone is also a class III antiarrhythmic agent that when given intravenously or orally has proved to be more effective than other agents in terminating AF and Af [B.N. Singh, F.V. Mody, B. Lopez, J.S. Sarina. Antiarrhythmic agents for atrial fibrillation: focus on prolonging atria] repolarization. Am J Cardiol 1999 Nov 4; 84: 161R-173R.]. Seventy-nine patients (56 with AF and 23 with Af) that consisted group Awere treated with ibutilide. Seventy-three (52 with AF and 21 with At) consisted group B and were treated with intravenous infusion of amiodarone. Results: The conversion rate of group A (ibutilide) was significantly higher than the conversion rate of group B (arniodarone) (80% vs. 57%, p=0.0054). As regards the kind of arrhythmia separately, for AF there wasn't significant difference (77% vs. 69%, p=ns) whereas for Af ibutilidewas superior to amiodarone(87%vs. 29%,p=0.003). The conversion rates of ibutilide didn't differ for AF andAf(77% vs. 87%,p=ns). Conclusions: lbutilide is more effective than arniodarone in converting recent-onset Af to SR whereas both drugs are equally effective in converting recent-onset AF to SR. (c) 2006 Elsevier Ireland Ltd. All rights reserved.