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.