br Methods We described our strategies for ablating AF

Methods We described our strategies for ablating AF in previous reports [34–36]. Therefore, we will discuss our methods for CFAE ablation, including CFAE-ablation combined with PVI, below.
Results
Representative cases of CFAE-ablation
Conclusions
Acknowledgments
Characteristics of the new anticoagulants Several new anticoagulants have been developed recently to overcome the limitations of warfarin. The new anticoagulants are either thrombin inhibitors, such as dabigatran, or factor Xa inhibitors, such as rivaroxaban, apixaban, and edoxaban, and these anticoagulants suppress either thrombin or factor Xa directly [1]. The characteristics of new anticoagulants differ from those of warfarin and are summarized in Table 1. In particular, their leukotriene receptor antagonist time is short, the time-to-peak-concentration (Tmax) is 1–4h, and the serum concentration corresponds to the anticoagulatory effect. Although the half-life of the new anticoagulants is about 12h, the rivaroxaban and the edoxaban are taken once a day and the dabigatran and the apoxaban twice a day. The efficacy of the new anticoagulants is not influenced by food intake or vitamin K levels; therefore, food restriction is not required during treatment. Compared to warfarin, the new anticoagulants interact much less with other medicines. The therapeutic range of the new anticoagulants is wide, and the effect of anticoagulation can be predicted from the amount of drug administered; thus, it is not necessary to monitor their anticoagulation effect. Overall, the characteristics of these novel anticoagulants are such that treatment with these anticoagulants does not have many of the difficulties that are frequently encountered with warfarin treatment.
Results of phase III trials of the novel anticoagulants The efficacy and safety of dabigatran, a direct thrombin inhibitor, and rivaroxaban and apixaban, direct factor Xa inhibitors, have been compared to those of warfarin in phase III trials [2–4]. The patients and warfarin management, particularly the time in therapeutic range, differed between these studies, precluding direct comparison of the primary or secondary endpoints and adverse events. However, a descriptive summary of the findings of each trial is presented in Table 2. All 3 drugs were not inferior to warfarin in terms of incidence of stroke, systemic embolism as the primary endpoint, and major bleeding (Fig. 1) [2–4]. Superiority to warfarin was observed regarding the incidence of stroke and systemic embolism for dabigatran (150mg dose) and apixaban. Moreover, dabigatran (110mg dose) and apixaban were shown to be superior to warfarin in preventing major bleeding. The incidence of hemorrhagic stroke and intracranial hemorrhage in patients treated with the novel anticoagulants was significantly lower than that in patients treated with warfarin (Fig. 2). The incidence of ischemic stroke was lower in patients treated with dabigatran (150mg) than in patients treated with warfarin. Gastrointestinal bleeding was frequently seen in patients treated with dabigatran (150mg) and rivaroxaban. Compared to patients treated with warfarin, patients treated with dabigatran showed withdrawal more frequently and those treated with apixaban showed withdrawal less frequently.
Use of different anticoagulants according to risk stratification The CHADS2 score is used to estimate the risk of stroke in patients with NVAF and to help determine whether anticoagulant therapy is required. This score is based on a point system in which 2 points are assigned for a history of stroke or transient ischemic attack (TIA) and 1 point each is assigned for congestive heart failure, history of hypertension, an age of at least 75 years, and diabetes. When the CHADS2 score is 2 or more, the annual risk of stroke is 4% or more. Therefore, a CHADS2 score of 2 or more is considered a high risk for stroke and is an indication for warfarin treatment. When the CHADS2 score is 1, warfarin treatment is not immediately recommended, but the benefits of reducing stroke incidence are considered against the risk of major bleeding. A previous study showed that compared to warfarin, dabigatran is associated with lower rates of stroke, systemic embolism, major bleeding, and intracranial bleeding in patients with low (0–1), medium (2), and high (≥3) CHADS2 scores [5]. Given the small number of patients with a CHADS2 score of 0 in that study (only 2.5% of the patients were in the low-risk group), the Japanese Circulation Society released an urgent statement recommending dabigatran for patients with CHADS2 scores of 1 [6] (Fig. 3).