AF Ablation Without Pulmonary Vein Isolation
What are the outcomes among patients undergoing catheter ablation of atrial fibrillation (AF) without pulmonary vein (PV) isolation?
One hundred and five patients with AF (paroxysmal in 24) underwent mapping with a multipolar catheter either during spontaneous (n = 65) or induced AF (n = 40). Regions displaying temporal and spatial dispersion (defined as nonsimultaneous activation of at least three adjacent bipoles) were identified in both the left and right atrium. These sites were then ablated with the endpoint of AF termination to either sinus rhythm or an intervening atrial tachycardia (AT), which was subsequently mapped and ablated. PV isolation was not performed. The outcomes of the study patients were compared with that of a historical group (n = 47).
The mean number of dispersion areas per patient was 5, each occupying a surface area of about 5 cm2. AF termination was achieved in 100 patients (95%; directly to sinus rhythm in 15%, and to AT in the remainder) using a mean of 20 minutes of radiofrequency energy. As compared with historical controls, the AF termination rate was higher, and the procedure duration was shorter in the study group. A repeat procedure for AT was performed in 76% of patients. After a mean of 1.4 procedures and a follow-up of 18 months, arrhythmia recurrence was noted in 15% of patients. However, 44% of the study population was using antiarrhythmic drugs (AADs).
The authors concluded that identification of fibrillatory electrograms displaying spatiotemporal dispersion facilitates mapping and ablation of AF, and is tailored to the individual patient.
The ultimate goals of AF ablation include durable eradication of the arrhythmia at a single session, and elimination of AAD and anticoagulant therapy, all while minimizing tissue destruction. At present, the possibility of checking off all of these items on the AF bucket list seems remote. Even the gold standard, that is, the cut-and-sew maze procedure, cannot claim to eliminate the arrhythmia ‘while minimizing tissue destruction.’ If the substrate maintaining AF is diffuse, can a minimalist approach reliably eliminate the arrhythmia? Although the high AF termination rate and short duration of radiofrequency ablation in this study are truly impressive, about 75% of patients still required a repeat procedure. Further, nearly one-half of the patients were taking AADs to maintain sinus rhythm. Although PV isolation was not performed at the index session, it is likely that the PVs were ablated at the repeat session, for example, to anchor linear lesions for AT. The incremental value of this approach should be tested in a randomized fashion.
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