Endocardial Ablation
Standalone endocardial catheter ablation is less invasive than surgical concomitant ablation and involves a catheter being guided through venous access points, entering the right atrium, and ultimately the left atrium where the endocardial ablation is performed. Patients with paroxysmal AF have higher success rates, such as freedom from atrial arrhythmias and less recurrences of repeat ablations compared to those with non-paroxysmal AF. After a secondary repeat ablation, paroxysmal AF patients experienced over 92% freedom from AF, whereas patients with persistent AF and long-standing persistent AF had lower secondary success rates of 88.1 and 80.9%, respectively.14 In a single center study, long-term success rates ranged from 28.4 to 51.1% recurrence-free rates after a single or three procedures, respectively, leaving a large percentage of patients with failed treatment.15 While contemporary trials have demonstrated that radiofrequency catheter and cryoballoon endocardial ablation may yield sufficient clinical outcomes for paroxysmal AF and even non-paroxysmal AF without advanced substrate, there are patients with advanced AF who tend to be more difficult to treat and have lower success rates and consequently more subsequent procedures after endocardial ablation.14 Recent studies of persistent AF have demonstrated rates of effectiveness of 54.8% to 61.7% at 12 and 15 months, respectively, after a single ablation procedure.16,17Tsai et al. recently published longer term follow up results from a Taipei hospital. After a single index ablation procedure, 100 patients with non-paroxysmal AF were followed very-long-term for over 5 years with a target follow up of 10 years. Only 16% of patients remained free of AF at 10 years, with the majority of AF recurrence (61.9%) at the one year mark, emphasizing the need for more effective and enduring treatment options for non-paroxysmal AF.18