A first-of-its-kind analysis on electrophysiological findings in patients with recurrent atrial tachyarrhythmia (ATa) following pulmonary vein isolation (PVI) using the novel pentaspline pulsed-field ablation (PFA) catheter reports a low incidence of pulmonary vein (PV) reconnection.
Shonta Tohoku (Cardiovascular Centre Bethanien, Frankfurt am Main, Germany) and others, writing in EP Europace, noted that PFA can present a “novel perspective” for atrial fibrillation (AF) ablation and sought to characterise the incidence of PV reconnection, the features of recurrent ATa, lesion quality following PFA-guided PV isolation and the amount of isolated posterior wall (PW) surface area (ISAPW%) ratio of the isolated to total surface area on PW. Patient selection criteria included those that underwent a second ablation procedure for recurrent ATa after initial PVI using the pentaspline PFA catheter were included in the study.
From May 2021 and April 2022, 360 patients with symptomatic paroxysmal or persistent AF were treated using Farapulse (Boston Scientifc) PFA system (31mm catheter, n=215, 35mm catheter, n=145), of these, 25 patients with 99 PVs who underwent a second procedure 6.1±4 months after the first, were analysed. Any patients older than 85 or younger than 18 years, or those found to be ineligible for treatment with oral anticoagulation, were excluded during the initial procedure.
In their analysis, Tohoku et al found an overall low rate of PV reconnection (9.1%), a reduced reconnection rate in PVs treated with 31mm catheter (3.4% vs. 35mm: 17.5%, p=0.0285), a complete durable isolation of all four PVs in 76% of patients, and a PVI lesion set associated PW-dependant AT being the most common ATa feature (8/13 ATs, 61.5%) observed at the second procedure. The authors assert electrical PV reconnection to generally be associated with AF recurrence—“[thus] creating durable PV lesion sets has been a crucial task to improve the long-term freedom from recurrent arrhythmia.”
On reflection, they highlight the predominance of LSPV as the most frequently reconnected PV in the data. They note, superior PVs are more commonly larger than the ipsilateral inferior PV, with the LS PV ostium being a complex anatomy consisting of LIPV and left atrial appendage. Subsequently, a 35mm catheter was selected in larger superior PVs, bridging the anatomical gap between catheter and PV ostium. However they note that as distance between tissue target and the source of the electric-field increases, the combination of anatomical feature and size selection may create a trend toward reconnection in LSPV.
Concerning recurrent ATa, the authors posit AF as the most dominant form, regardless of energy source following PVI. They reported a low incidence of lesion set related AT after contemporary balloon-based ablations, although “unexpectedly” they note lesion set associated with AT was “frequently observed […] [implying] a need to reconsider the way of lesion creation in anticipation of the future clinical course.”
They continue, stating adjustments to catheter configuration at energy delivery to affect small lesion formation may be an option to prevent lesion set association critical isthmus—although conversely more extensive lesion formation may also be a viable option. The researchers highlight that the PVI durability in the overall patient population is still “unclear” due to their limited selection criteria which only included patients with symptomatic recurrent ATa after PFA-guided PVI. However Tohoku and colleagues conclude that the indication for preventative elimination of the potential isthmus of PW should be debated for the “future tailored ablation strategy.”