CATHETER ABLATION FOR ATRIAL FIBRILLATION USING THE ABLATION INDEX-HIGH
POWER STRATEGY. Do we have the ideal target?
Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation
for atrial fibrillation (AF) However AF recurrence after a single
ablation procedure is common and often attributed to ineffective lesion
delivery during PVI. In this issue of the Journal of Cardiovascular
Electrophysiology, Chen et al reported their experience with 122
patients who underwent an ablation index-high power (AI-HP) strategy RF
ablation for AF using 50W power, targeting AI values of 550 on the
anterior left atrium (LA), 400 on the posterior wall and inter-lesion
distance (ILD) 6mm. They achieved 1st pass PVI in 96.7% of cases, mean
RF time was 11.5min and total procedure time was only 55.8min. All
patients had 72h-Holter monitor and trans-telephonic follow up. They
reported 89.4% arrhythmia free survival among patients with paroxysmal
AF and 80.4% among patients with persistent AF at 15-month follow up.
Sixty (49%) patients had luminal esophageal temperature (LET)
>390C out of which 3 (2.5%) had asymptomatic endoscopic
esophageal erosions/erythema. Four (3%) patients had clinically
apparent steam pops during ablation with no adverse clinical sequela.
While AI-HP guided RF ablation may be an attractive strategy for PVI
that likely reduces procedure times and probably has comparable efficacy
to conventional ablation settings, its safety requires further
evaluation. Feedback from the ablated tissue may need to be incorporated
into optimized ablation energy parameters to further improve outcomes.