Abstract 15918: Switching Patients with Atrial Fibrillation from Amiodarone to Dronedarone: Results of the ARTEMIS AF Studies
Switching a patient from one antiarrhythmic drug (AAD) to another is usually timed to minimize arrhythmia recurrence and drug-drug adverse reactions. For most AADs, this is based on stopping an AAD for 5 half-lives before starting another. Amiodarone is the most frequently prescribed antiarrhythmic for atrial fibrillation (AF) and has a long half-life of 53 days. Dronedarone is an amiodarone analog and little is known about the optimal timing of switching from amiodarone to dronedarone. The ARTEMIS Loading and Long-term studies evaluated switching patients with paroxysmal or persistent AF from amiodarone to dronedarone in a randomized fashion in 3 groups: immediately, after a 2-week, or after a 4-week washout of amiodarone. Patients who did not medically convert to sinus rhythm at the end of amiodarone loading underwent electrical (DC) cardioversion. Inclusion criteria for the ARTEMIS Loading Study included patients who had persistent AF >72 hours, at least 1 cardiovascular risk factor and a QTc <500 msec. In ARTEMIS Loading, 176 patients, with a mean age of 66.2 years, were randomized after a 28+2 day load of oral amiodarone. 29.5% had a history of congestive heart failure and 95.7% had a LVEF >40%. The median persistent AF duration was 52 days and the mean left atrial diameter was 45.8 mm. AF recurrence trended less in the immediate switch versus 4-week washout group (HR 0.65 [95% CI 0.34-1.23]; p=0.14) and in the 2-week washout versus the 4-week washout group (HR 0.75 [95% CI 0.41-1.37]; p=0.32). The occurrence of bradycardic episodes was not different between the 3 groups, although first-degree atrioventricular block and QTc >500 msec was more common in the immediate switch group. No patients had to stop dronedarone for a major adverse event. An additional 107 patients on long-term amiodarone were switched to dronedarone using similar timing options and were analyzed alone and in combination with the loading study results. In conclusion, in this population of AF patients with previous amiodarone loading, immediate switch appears to be a convenient and effective option with an acceptable safety profile. These two studies are supported by SANOFI and can be found on clinicaltrials.gov as NCT01140581 (ARTEMIS AF Loading) and NCT01199081 (ARTEMIS AF Long-Term).
- © 2012 by American Heart Association, Inc.