3.3 Comparisons of CB procedures among the CST success group,
CST failure group, and control group
Two factors of CB applications to the superior PVs—namely, NT and
percentage of complete occlusions—were compared among the three groups
(Figure 2). Differences in the NT among the three groups are illustrated
in Figure 2A; the NT was significantly lower in the CST success and
control groups than in the CST failure group (p<0.001). Of
note, complete occlusion of the superior PVs with the CB was
significantly more highly achieved in the CST success group than in the
CST failure and control groups (Figure 2B).
We analyzed the NT distribution during incomplete and complete occlusion
applications, as shown by the graph in Figure 3. The NT in the CST
success group was mainly observed in the temperature range of ≤-46°C
when complete occlusion was achieved. In contrast, the NT in the CST
failure group was widely scattered throughout all temperatures,
including those during an incomplete occlusion of the superior PVs and
during complete occlusions other than those that were mainly observed in
the CST success group. As suggested by this graph, the CST ablation
technique was always effective if CB ablation of the superior PVs was
performed with both complete occlusion and NT ≤-46°C and was almost
always ineffective if it did not meet these two criteria (sensitivity,
100%; specificity, 93.8%). When only complete PV occlusion was used as
the criterion, the sensitivity and specificity were 93.8% and 87.5%,
respectively, which were worse than those of the abovementioned
criteria.