Procedure Characteristics
In the second study, PAF patients (n=80) were randomly assigned either
to the FTI protocol (FTI ≥400 g·s, n=40) or the TAI protocol (n=40). Our
AI-blinded retrospective analysis demonstrated that AI 530 was enough
for a success of first-pass isolation and was supposed to create
transmural lesion in the thickest WT segment and in the first study; the
left-PV (the LLR) had the thickest average WT. Optimal AI for creating
transmural lesion per millimeter (AI/mm) was therefore calculated by AI
530 divided by 6.0 mm (the average WT in the LLR), resulting in 90
AI/mm. In TAI, target AI in each segment was calculated by the formula
as follows: [90 (AI/mm) × individual WT (mm) in each segment].
Table 2 shows the baseline characteristics in FTI and TAI; there were no
significant differences in the patient demographics between the both
groups. In TAI, the average WT and target AI in each segment are shown
in Figure 5, and these values in each patient are shown in Supplemental
Table 3. PVI was completed in all patients.
The success rate of first-pass isolation was significantly higher in TAI
than in FTI (88% and 65%, Figure 6A). The prevalence of residual
conduction gap/PV potential after a circular RF application was
significantly lower in TAI than in FTI (15% and 45%, Figure 6B). The
incidence of spontaneous PV reconnection/drug-evoked dormant conduction
were comparable between the two groups (18% and 21%, Figure 6C). The
mean procedure time to complete PVI significantly decreased in TAI than
in FTI (52±17 min and 83±27 min, p<0.05, Figure 6D), showing
37% reduction by TAI. These suggest that FAI improves the efficacy of
PVI procedure by increasing the rate of first-pass isolation with
reducing the residual conduction gap/PV potentials, resulting in
shortening the time for PVI.