Dronedarone after Catheter Ablation of Atrial Fibrillation: A New Option in Hybrid Therapy

Background and Aim: Catheter ablation has become the therapy of choice in patients with symptomatic, recurrent, drug-refractory atrial fibrillation (AF). However, frequent AF recurrences often necessitate an adjunctive antiarrhythmic drug (AAD) therapy. Dronedarone is a new class III AAD with modest side effects. We compared a conventional AAD therapy (CAAT) with class I/III AADs to a novel therapy with dronedarone (NAAT)in regard to AF recurrences and improvement of symptoms.

Methodology: One hundred twenty five consecutive patients (84 men; mean age 62.1±12.4 years) with symptomatic paroxysmal (n=70) or persistent (n=55) drug refractory AF were enrolled in an open-label randomized study. Following successful pulmonary vein isolation (PVI) patients were randomized to receive CAAT (n=50), NAAT (n=50) or no AAD therapy (=control; n=25). Follow-up visits were scheduled at 3, 6, 9, and 12 months post ablation. Seven-day-Holter monitoring and patients’ histories served as indicators of treatment success. Bar signs of AF recurrence AADs were discontinued 6 months post ablation.

Results: The pre-ablation European Heart Rhythm Association (EHRA)-score decreased from 2.8±0.4 to 1.4±0.6 (NAAT) and 1.5±0.7 (CAAT) 6 months after PVI (1.7±0.7 in the control group). Fifty patients experienced an arrhythmia recurrence within 3 months. After 6 months, both hybrid therapy groups showed a significant advantage over the control group favoring sinus rhythm (SR).Whereas CAAT could retain its significant benefit at 9 months NAAT lost its relative advantages with only a positive trend remaining over the control group but a significant disadvantage compared to CAAT patients. At this point AF recurrences were found in 34% of NAAT patients, 26% of CAAT patients, and 40% of control patients. At 12 months, however, no group could preserve a significant lead over either of the others.

Conclusion: Dronedarone after PVI is safe and effective. Compared to a CAAT, NAAT reveals similar improvements of EHRA-scores and non-significantly different AF recurrence rates from 9 months on. Despite this, CAAT keeps significantly more patients in SR 9 months after PVI.