After a single procedure of circumferential ablation with PVI and noninducibility, 82% patients did not have recurrence of AF. The inducibility of AF was related to the recurrence of AF. The atrial substrate affected the outcome of the inducibility.

Our study showed that for persistent AF ablation, a specified substrate modification guided by nonlinear phase mapping could eliminate localized re-entry and non-pulmonary focal sources after pulmonary vein isolation.

The LA voltage was lower than the RA, and the atrial voltage correlated with the TAT. Electroanatomical remodeling of the atria could be crucial to the maintenance of AF. The LA substrate properties may play an important role in the recurrence of AF after catheter ablation of AF.

For Taiwanese patients 50 to 64 years of age, the annual stroke risk was 1.78%, which may exceed the threshold for OAC use for stroke prevention. The annual risk of ischemic stroke for AF patients <50 years of age was 0.53%, which was truly low-risk, and OACs could be omitted. Whether resetting the age threshold to 50 years could refine current clinical risk stratification for Asian AF patients deserves further study.

Background Data comparing outcomes in heart failure ( HF ) across Asia are limited. We examined regional variation in mortality among patients with HF enrolled in the ASIAN ‐HF (Asian Sudden Cardiac Death in Heart Failure) registry with separate analyses for those with reduced ejection fraction ( EF ; <40%) versus preserved EF (≥50%). Methods and Results The ASIAN ‐ HF registry is a prospective longitudinal study. Participants with symptomatic HF were recruited from 46 secondary care centers in 3 Asian regions: South Asia (India), Southeast Asia (Thailand, Malaysia, Philippines, Indonesia, Singapore), and Northeast Asia (South Korea, Japan, Taiwan, Hong Kong, China). Overall, 6480 patients aged >18 years with symptomatic HF were recruited (mean age: 61.6±13.3 years; 27% women; 81% with HF and reduced r EF ). The primary outcome was 1‐year all‐cause mortality. Striking regional variations in baseline characteristics and outcomes were observed. Regardless of HF type, Southeast Asians had the highest burden of comorbidities, particularly diabetes mellitus and chronic kidney disease, despite being younger than Northeast Asian participants. One‐year, crude, all‐cause mortality for the whole population was 9.6%, higher in patients with HF and reduced EF (10.6%) than in those with HF and preserved EF (5.4%). One‐year, all‐cause mortality was significantly higher in Southeast Asian patients (13.0%), compared with South Asian (7.5%) and Northeast Asian patients (7.4%; P <0.001). Well‐known predictors of death accounted for only 44.2% of the variation in risk of mortality. Conclusions This first multinational prospective study shows that the outcomes in Asian patients with both HF and reduced or preserved EF are poor overall and worst in Southeast Asian patients. Region‐specific risk factors and gaps in guideline‐directed therapy should be addressed to potentially improve outcomes. Clinical Trial Registration URL : https://www.clinicaltrials.gov/ . Unique identifier: NCT 01633398.

Background Oral anticoagulants (OACs) are not recommended for ‘low-risk’ patients with atrial fibrillation (AF). We investigated the incidences of new risk factors developing, and the temporal trends in the CHA2DS2-VASc score in initially ‘low-risk’ AF patients. Second, we propose a reasonable timing interval at which stroke risk should be reassessed for such AF patients. Methods We studied 14,606 AF patients who did not receive anti-platelet agents or OACs with a baseline CHA2DS2-VASc score of 0 (males) or 1 (females). The CHA2DS2-VASc scores of patients were followed up and updated until the occurrence of ischaemic stroke or mortality or 31 December 2011. The associations between the prescription of warfarin and risk of adverse events once patients' scores changed were analysed. Decile values of durations to incident co-morbidities and from the acquirement of new co-morbidities to ischaemic stroke were studied. Results During a mean follow-up of 4 years, 7,079 (48.5%) patients acquired at least one new stroke risk factor component(s) with annual risks of 6.35% for hypertension, 3.68% for age ≥ 65 years, 2.77% for heart failure, 1.99% for diabetes mellitus and 0.33% for vascular diseases. The incidence for CHA2DS2-VASc score increments was 12.1%/year. Initiation of warfarin was associated with a lower risk of adverse events (adjusted hazard ratio, 0.530; 95% confidence interval, 0.371–0.755). Among 6,188 patients who acquired new risk factors, 80% would acquire these co-morbidities after 4.2 months of AF diagnosis. The duration from the acquirement of incident co-morbidities to the occurrence of ischaemic stroke was longer than 4.4 months for 90% of the patients. Conclusion The CHA2DS2-VASc score increases in approximately 12% of initially ‘low-risk’ AF patients each year, and the initiation of warfarin once the score changed was associated with a better prognosis. Three to four months may be a reasonable timing interval at which stroke risk should be reassessed so that OACs could be prescribed in a timely manner for stroke prevention.

Background-Identification of critical atrial substrates in patients with nonparoxysmal atrial fibrillation (AF) failing to respond to pulmonary vein isolation is important. This study investigated the signal characteristics, substrate nature, and ablation results of rotors during AF. Methods and Results-In total, 53 patients (age=55±8), 31 with persistent AF and 22 with long-lasting AF, underwent pulmonary vein isolation and substrate modification of complex fractionated atrial electrograms. Small-radius-reentrant rotors were identified from signal analyses of the dominant frequency and fractionation interval and nonlinear analyses (newly developed, beat-to-beat nonlinear measurement of the repetitiveness of the electrogram morphology >6 seconds). In 15% of the patients, activation maps demonstrated occurrences of rotor-like small-radius reentrant circuits (n=9; 1.1 per patient; cycle length=110±21 ms; diameter=11±6 mm) with fibrillation occurring outside these areas. Rotors were identified by conventional point-by-point mapping and signal analyses and were subsequently eradicated by catheter ablation in these patients. Persistent AF for <1 year, a smaller left atrial size, substrates with higher mean voltages and shorter total activation durations predicted a higher incidence of rotors (all P<0.05). In the multivariable model, areas of reentrant circuits exhibited a higher dominant frequency, kurtosis, and higher degree of a beat-to-beat electrogram similarity than areas without or outside the rotors (all P<0.05). Conclusions-Rotor-like re-entry with fibrillatory conduction was found in a limited number of patients with nonparoxysmal AF after pulmonary vein isolation. Those areas were characterized by rapid repetitive activity with a high degree of electrogram similarity. Methods Patient CharacteristicsWe enrolled 53 patients (55±8 years) with symptomatic drug-refractory nonparoxysmal AF who underwent radiofrequency ablation guided by NavX system (St Jude Medical Inc, MN). The study cohort included 31 patients (58%) with persistent AF (duration <1 year but >7 days) and 22 patients (42%) with long-lasting persistent AF (duration of ≥1 year; Table 1). All patients presented with incessant AF in the beginning of the procedure. The patients were excluded from the study if they were in sinus rhythm or had spontaneous termination of AF before the PVI. Electrophysiological StudyAn electrophysiological study and catheter ablation in the fasting state were performed in each patient after informed consent was obtained. All antiarrhythmic drugs, except amiodarone, were discontinued for ≥5 half-lives before the start of the procedure. Overall, 19 patients (36%) were treated with amiodarone before the procedure because of symptomatic AF, but no patients received that drug during the electrophysiological procedure. Electroanatomic mapping was performed in all patients. The details of the mapping have been described in other previous studies. 10,11 Signal Acquisition and Linear AnalysisDuring AF, point-by-point mapping was ...

The 3-D mapping system provided a good reconstruction of CTI, which may help in the RFA in patients with a complex anatomy of the CTI.