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.