Cardioversion of atrial fibrillation with ibutilide: When is it most effective?

Abstract

SummaryBackground: Atrial fibrillation (AF) is found in 1% of persons above the age of 60 years. More than 5% of the population older than 69 years and about 14% of octogenarians are at risk for this arrhythmia. It is estimated that 1.5 to 3 million persons in the United States alone suffer from AF. The public health implications and attendant morbidity are a significant drain on our health care system.Hypothesis: The purpose of this study was to determine the clinical and echocardiographic predictors of success in converting AF of ≥ 24 h duration.Methods: Demographic and clinical and echocardiographic parameters of 101 patients with recent onset AF (> 24 h) who received ibutilide were studied.Results: Of 101 patients, 56 (55%) converted to sinus rhythm. Age, gender, hypertension, diabetes mellitus, left ventricular ejection fraction (≤ 35%), congestive heart failure, and previous medication for rate control had no significant effect on the conversion rate. Conversion rate was only 30% (9/30 patients) in the presence of an enlarged left atrium (LA ≥ 5 cm) and 37.7% (23/61 patients) in the presence of mitral valve disease (MVD), whereas the conversion rate was 82.5% (33/40 patients) in the absence of MVD and 85% (29/34 patients) in the absence of both enlarged LA and MVD (p = < 0.001). Patients with coronary artery disease (CAD) also exhibited a significantly greater response to ibutilide than patients without CAD (77 vs. 46%, p-value 0.005).Conclusion: As a therapy for cardioversion of AF, ibutilide is most effective in a selected subgroup patients, such as in pa-

A randomized, controlled trial of RSD1235, a novel anti-arrhythmic agent, in the treatment of recent onset atrial fibrillation

“…Furthermore, responses that take 24 h to manifest, such as with amiodarone, are of limited usefulness for acute intravenous conversion of AF. Class III anti-arrhythmics, such as ibutilide and dofetilide, show 20% to 30% net efficacy rates for conversion of AF, with slightly higher efficacy in termination of atrial flutter (3,18,20,21). These latter agents are associated, however, with a relatively high incidence of drug-induced pro-arrhythmia (18,20).…”

“…Electrical cardioversion is effective in restoring sinus rhythm but requires procedural sedation or anesthesia and is not successful in all cases. Currently available converting agents have highly variable efficacy and several safety limitations associated with their use (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21). In addition, placebo-controlled trials that establish the efficacy and safety of these pharmacologic therapies for acute conversion are limited.…”

Comparison of intravenous ibutilide vs. propafenone for rapid termination of recent onset atrial fibrillation*

“…It prolongs human atrial and ventricular action potential duration and refractory period (9). In previous reports, ibutilide successfully converted AF to sinus rhythm in 34 to 82.5% of patients in some trials (1,3–5), while the conversion rates of the comparator drugs (including procainamide and sotalol) were less than 20%.…”

“…Atrial fibrillation (AF) is a common arrhythmia, and its incidence increases with age. It affects more than 5% of the US population of over 65 years old and 10% of those over 80 years of age (1). In China, it affects 3.1% of over 70 years old, and 7.5% of those over 80 years of age (2).…”

Pharmacological Treatment of Atrial Fibrillation: Mechanisms of Action and Efficacy of Class III Drugs

“…Initial clinical results from a randomized, double-blind, placebo-controlled trial indicated that ibutilide is also effective in terminating atrial fibrillation and flutter after cardiac surgery [71]. Although it was not approved for this indication, preliminary results indicated that ibutilide could also prevent reinduction of sustained ventricular tachycardia in patients with coronary artery disease undergoing electrophysiological study [72].…”