Antiarrhythmic therapy prior to ablation

TSUKUBA, JAPAN. Having been in permanent atrial fibrillation for an extended period is associated with a poorer outcome of catheter ablation. Japanese cardiologists/electrophysiologists now report that extensive antiarrhythmic therapy prior to ablation results in improved outcomes.

Their study included 51 permanent afibbers (7 women) aged between 36 and 74 years. All patients had been previously unsuccessfully treated with class I (flecainide, propafenone) or class III (amiodarone) antiarrhythmic drugs (AADs). The mean duration of AF prior to enrolment was 36 months. Following enrolment all patients were prescribed a combination of amiodarone or bepridil (a calcium channel blocker) and a class I antiarrhythmic such as flecainide or propafenone. The most popular combination was flecainide and bepridil prescribed for 41% of patients.

An average of 1.5 months after initiation of the combined AAD therapy, 65% (33 patients) had converted to normal sinus rhythm (NSR), while the remaining 18 patients remained in afib (AF group). It was noted that fewer members (21%) of the NSR group had been in permanent AF for more than 3 years than in the AF group (44%). It was evident that members of the NSR group had experienced a significant increase in left ventricular ejection fraction, a decrease in left atrial diameter, and a reduction in plasma BNP level due to their successful AAD therapy. However, 4 patients (7.8%) experienced adverse effects from the AAD treatment, notably bradycardia and prolongation of QT interval.

After 3 months or more (average of 6 months) of combined AAD therapy, all study participants underwent a pulmonary vein isolation procedure including a right atrial flutter ablation (bidirectional block line at the cavotricuspid isthmus) and additional lesion sets as required (roof line, superior vena cava isolation, and ablation of complex, fractionated atrial electrograms). In the NSR group only 9% of ablatees required cardioversion at the end of the procedure, while in the AF group 39% needed cardioversion to achieve normal sinus rhythm. No complications were observed during the 14-month post-ablation follow-up period. At the end of follow-up 61% of the patients in the NSR group and 22% in the AF group were still in NSR.

The authors conclude that restoration of normal sinus rhythm in permanent afibbers using a combination of class I and class III antiarrhythmics results not only in an improved ejection fraction, reduced left atrium size, and lower BNP concentration, but also markedly improves the outcome of catheter ablation.

Igarashi, M, et al. Effect of restoration of sinus rhythm by extensive antiarrhythmic drugs in predicting results of catheter ablation of persistent atrial fibrillation. American Journal of Cardiology, Vol. 106, 2010, pp. 62-68

Editorís comment: It certainly would seem worthwhile for permanent afibbers to consider going on the combination therapy while awaiting their ablation. NOTE: I am not sure why the Japanese researchers classify bepridil as a class III antiarrhythmic. As a calcium channel blocker it would normally be classified as class IV.