This study shows that mapping and ablation using a robotic sheath guidance system are critically dependent on generated force. These findings suggest that ablative lesion size is optimized by the application of 10-20 grams of contact force, although mapping requires lower-force application to avoid image distortions.

Our finding that markers of collagen turnover were elevated in patients who experienced AF recurrence after ablation indicate that these markers might be a useful guide to identify a subgroup of AF patients who require extensive ablation strategies. A 2-month postablation elevation in collagen turnover markers suggests that the wound healing process persists for that long after ablation.

BackgroundLarge-scale investigations on the use of oral anticoagulants including direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) have not included Japanese patients.MethodsWe established the multicenter SAKURA AF Registry to support prospective observational research on the status of anticoagulation treatment, especially with DOAC, for AF in Japan. We enrolled 3266 AF patients treated with warfarin (n=1577) or any of 4 DOACs (n=1689) from 63 institutions (2 cardiovascular centers, 13 affiliated hospitals or community hospitals, and 48 private clinics) in the Tokyo area.ResultsWe conducted our first analysis of the registry data, and although we found equivalent mean age between the DOAC and warfarin users (71.8±9.5 vs. 72.3±9.4 years, p=0.2117), we found a slightly lower risk of stroke (CHADS2 score of 0 or 1 [46.9% vs. 39.4%, p<0.0001]) and significantly better creatinine clearance in DOAC users (70.4±27 vs. 65.6±25.7 mL/min, p<0.0001). Importantly, we documented under-dosing in 32% of warfarin users and inappropriate-low-dosing in 19.7–27.6% of DOAC users.ConclusionsOur initial analysis of the SAKURA AF Registry data clarified the real-world use of anticoagulants, which includes DOACs and warfarin in Japan. The DOAC users were at a lower risk for stroke than the warfarin users. In 20–30% of DOAC users, the dose was inappropriately reduced.

bleeding complications among patients with AF, compared with use of vitamin K antagonists. 2-5 Review of real-world registries in Japan has indicated the incidence rate of stroke with DOAC therapy to be similar to that with warfarin but with a lower risk for major bleeding events for DOACs A trial fibrillation (AF) is the most common arrhythmia in elderly individuals, currently affecting approximately 0.6% of the Japanese population, and the prevalence of AF is expected to continue to rise in Japan, affecting an estimated 10 million people by 2030. 1 AF is a strong risk factor for stroke and death. Randomized clinical trials (RCTs) have shown the benefit of direct oral anticoagulant (DOAC) therapy in reducing the risk of stroke and Editorial p 707

Background— Although increased epicardial adipose tissue (EAT) volume is known to be associated with increased prevalence of atrial fibrillation (AF), the exact mechanisms are unclear. Therefore, we investigated whether EAT locations were associated with high dominant frequency (DF) sites or complicated fractionated atrial electrogram sites during AF. Methods and Results— Three-dimensional reconstruction computed tomography images depicting EAT volumes (obtained by 320-detector-row multislice computed tomography) were merged with NavX-based DF and complicated fractionated atrial electrogram maps obtained during AF for 16 patients with paroxysmal AF and for 18 patients with persistent AF. Agreement between locations of the EAT, especially EAT surrounding the left atrium, and of high DF or complicated fractionated atrial electrogram sites was quantified. In addition, serum biomarker levels were determined. EAT surrounding the left atrium volumes was significantly greater in patients with persistent AF than in patients with paroxysmal AF (52.9 cm 3 [95% CI, 44.2–61.5] versus 34.8 cm 3 [95% CI, 26.6–43.0]; P =0.007). Serum high-sensitivity C-reactive protein and interleukin-6 levels were significantly higher in persistent AF patients than in paroxysmal AF patients (median high-sensitivity C-reactive protein, 969 ng/mL [interquartile range, 307–1678] versus 320 ng/mL [interquartile range, 120–660]; P =0.008; median interleukin-6, 2.4 pg/mL [interquartile range, 1.7–3.2] versus 1.3 [interquartile range, 0.8–2.4] pg/mL; P =0.017). EAT locations were in excellent agreement with high DF sites (κ=0.77 [95% CI, 0.71–0.82]) but in poor agreement with complicated fractionated atrial electrogram sites (κ=0.22 [95% CI, 0.13–0.31]). Conclusions— Increased EAT volume and elevation of inflammatory biomarkers are noted in persistent AF rather than paroxysmal AF patients. High DF sites are located adjacent to EAT sites. Thus, EAT may be involved in the maintenance of AF.

Background: Whether epicardial adipose tissue (EAT) is independently associated with atrial fibrillation (AF) and outcome after catheter ablation (CA) for AF remains unclear. Conclusions: EAT volume increases in AF patients independent of conventional risk factors and is greater in patients with lone AF than in non-AF patients. EAT volume might be useful for predicting AF recurrence after CA. (Circ J 2011; 75: 2559 - 2565 Methods and

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A high follow-up rate allowed us to obtain reliable data on the status of OAC use and therapeutic outcomes among AF patients in Japan. Warfarin and DOACs appear to yield equivalent 3-year stroke and all-cause mortality rates, but DOACs appear to reduce the risk of major bleeding.