First-line catheter ablation for atrial fibrillation - lower than recommended doses of antiarrhythmic drugs may have contributed to their inferiority: Analysis of randomized controlled studies comparing ablation with antiarrhythmic drugs.

Catheter ablation plays a pivotal role in the management of atrial fibrillation (AF). Recent randomized controlled studies have shown that catheter ablation is superior to conventional antiarrhythmic medical treatment as first-line therapy in reducing symptoms, AF recurrences, and preventing progression of AF. If the examined antiarrhythmic medical regimens were given in therapeutic and adequate doses remains an open question. We performed a PubMed and Medline search for randomized trials comparing first-line antiarrhythmic drug therapy with catheter ablation of AF. Among the 442 patients randomized to the drug arm, 20% to 43% received flecainide, propafenone, and sotalol at lower than recommended doses. Additionally, between 2.5 % and 10.4 % of these patients either have not received or discontinued the designated therapy with Class I/III drugs early. Notably, up to 10% of the patients in the ablation arm were adjunctively treated with antiarrhythmic drugs. This may have contributed to the reported superiority of catheter ablation compared to antiarrhythmic drug therapy.