Mechanism of Early Recurrence
Previous studies with patients in the non-CF era have reported an approximately 50% prevalence of ER after ablation and a higher incidence of LR, ranging between 41.1% and 90%, in cases with ER during the 3-month blanking period.3, 9, 10 The present study showed that 55.7% patients in the Non-CF group had ER during the 3-month blanking period and 59.3% of them had LR. These results were consistent with those of previous studies. On the other hand, in CF ablation cases, only 35.2% cases experienced ER, and 52.4% of those with ER also had LR. These results were also consistent with those of a previous study.11
The mechanisms of ERs are considered to be post-ablation transient factors, such as inflammatory changes, in addition to reconnection of PV or residual extra-PV triggers.1 A previous histopathological study had demonstrated that RF energy delivery causes inflammatory responses after the ablation procedure.12Furthermore, a greater inflammatory response after an RF ablation procedure has been associated with ER, and a longer RF ablation time and total procedure time are significant predictors for post-ablation inflammation and myocardial injury.13 In the present study, the degree of elevation in WBC and CRP levels after ablation was significantly smaller in patients who underwent CF-guided ablation (Table 2). The RF delivery time was shorter, and the amount of RF energy delivered was smaller in patients who underwent CF-guided ablation (Table 2). Appropriate force of tissue–catheter contact, and stability of RF delivery provided by CF technology may result in more successful PVI, without excessive RF delivery, and will reduce the inflammatory response. A lower inflammatory response may partly explain the lower incidence of ER in the CF-group.