The answer is yes the success rate is significantly lower for persistent than for paroxysmal atrial fibrillation. However, recurrences can be seen in the 3 months following an ablation while the atrial ablation lines scar up and prevent further a fib, and these are usually not signs of a failed ablation.
The third point is that you should consult your EP that performed the procedure, because he may have not performed a flutter line addressing typical flutter because you had no history of this arrhythmia. If so then he may perform this ablation which is significantly simpler than the PVI and involves usually only ablation in the right atrium.