the major problem in randomized studies comparing the efficacy and safety
of catheter ablation and antiarrhythmic medication has been high
frequency of crossover to radiofrequency ablation by medical-therapy patients. For example, in the MANTRA-PAF and the RAAFT-2 trial 36% and
47% of the patients initially assigned to AAD therapy eventually
underwent RFA, respectively[9,12]. Therefore, on-treatment (per protocol) analysis is likely to reveal subtle differences between the RFA and
AAD groups better than the ITT analysis.