The impact of early cryoballoon ablation on clinical outcome in patients with atrial fibrillation: From the Korean cryoballoon ablation registry.

INTRODUCTION: Influence of early atrial fibrillation (AF) ablation, particularly cryoballoon ablation (CBA), on clinical outcome during long-term follow-up has not been clarified. The objective was to determine whether an early CBA (diagnosis-to-ablation of ≤6 months) strategy could affect freedom from AF recurrence after index CBA. METHODS: The study included 2605 patients from Korean CBA registry data with follow-up >12 months after de novo CBA. The primary outcome was recurrence of atrial tachyarrhythmias (ATs) of ≥30-s after a 3-month blanking period. RESULTS: Compared to patients in early CBA group, patients in late CBA group had higher prevalence of diabetes, congestive heart failure, and chronic kidney disease, and higher mean CHA2 DS2 -VAS score. During mean follow-up of >21 months, ATs recurrence was detected in 839 (32.2%) patients. The early CBA group showed a significantly lower 2-year recurrence rate of ATs than the late CBA group (26.1% vs. 31.7%, p = 0.043). In subgroup analysis, the early CBA group showed significantly higher 1-year and 2-year freedom from ATs recurrence than the late CBA group only in paroxysmal atrial fibrillation (PAF) patients in overall and propensity score matched cohorts. Multivariate analysis showed that early CBA was an independent factor for preventing ATs recurrence in PAF (hazard ratio: 0.637; 95% confidence intervals: 0.412-0.984). CONCLUSION: Early CBA strategy, resulting in significantly lower ATs recurrence during 2-year follow-up after index CBA, might be considered as an initial rhythm control therapy in patients with paroxysmal AF.

Long-term clinical impact of early recurrence of atrial tachyarrhythmia after cryoballoon ablation in patients with atrial fibrillation.

INTRODUCTION: The impact of early recurrence of atrial tachyarrhythmia (ERAT) within the 90-day blanking period on long-term outcomes in atrial fibrillation (AF) patients undergoing cryoballoon ablation (CBA) is controversial. This study aimed to assess the relationship between ERAT and late recurrence of atrial tachyarrhythmia (LRAT) post-CBA. METHODS: Utilizing data from a multicenter registry in Korea (May 2018 to June 2022), we analyzed the presence and timing of ERAT (<30, 30-60, and 60-90 days) and its association with LRAT risk after CBA. LRAT was defined as any recurrence of AF, atrial flutter, or atrial tachycardia lasting more than 30 s beyond the 90 days. RESULTS: Out of 2636 patients, 745 (28.2%) experienced ERAT post-CBA. Over an average follow-up period of 21.2 ± 10.3 months, LRAT was observed in 874 (33.1%) patients. Patients with ERAT had significantly lower 1-year LRAT freedom compared to those without ERAT (42.6% vs. 85.5%, p < .001). Multivariate analysis identified ERAT as a potential predictor of LRAT, with a hazard ratio (HR) of 3.98 (95% confidence interval [CI], 3.47-4.57). Significant associations were noted across all examined time frames (HR, 3.84; 95% CI, 3.32-4.45 in <30 days, HR, 5.53; 95% CI, 4.13-7.42 in 30-60 days, and HR, 4.29; 95% CI, 3.12-5.89 in 60-90 days). This finding was consistently observed across all types of AF. CONCLUSION: ERAT during the 90-day blanking period strongly predicts LRAT in AF patients undergoing CBA, indicating a need to reconsider the clinical significance of this period.

Association between Rapid Ventricular Response and Stroke Outcomes in Atrial Fibrillation-Related Cardiac Embolic Stroke.

INTRODUCTION: Patients with atrial fibrillation-related stroke (AF-stroke) are prone to developing rapid ventricular response (RVR). We investigated whether RVR is associated with initial stroke severity, early neurological deterioration (END) and poor outcome at 3 months. METHODS: We reviewed patients who had AF-stroke between January 2017 and March 2022. RVR was defined as having heart rate >100 beats per minute on initial electrocardiogram. Neurological deficit was evaluated with National Institutes of Health Stroke Scale (NIHSS) score at admission. END was defined as increase of ≥2 in total NIHSS score or ≥1 in motor NIHSS score within first 72 h. Functional outcome was score on modified Rankin Scale at 3 months. Mediation analysis was performed to examine potential causal chain in which initial stroke severity may mediate relationship between RVR and functional outcome. RESULTS: We studied 568 AF-stroke patients, among whom 86 (15.1%) had RVR. Patients with RVR had higher initial NIHSS score (p < 0.001) and poor outcome at 3 months (p = 0.004) than those without RVR. The presence of RVR [adjusted odds ratio (aOR) = 2.13; p = 0.013] was associated with initial stroke severity, but not with END and functional outcome. Otherwise, initial stroke severity [aOR = 1.27; p = <0.001] was significantly associated with functional outcome. Initial stroke severity as a mediator explained 58% of relationship between RVR and poor outcome at 3 months. CONCLUSION: In patients with AF-stroke, RVR was independently associated with initial stroke severity but not with END and functional outcome. Initial stroke severity mediated considerable proportion of association between RVR and functional outcome.

Association between body mass index and results of cryoballoon ablation in Korean patients with atrial fibrillation: an analysis from the Korean Heart Rhythm Society Cryoablation registry.

AIMS: Pulmonary vein isolation using cryoablation is effective and safe in patients with atrial fibrillation (AF). Although both obesity and underweight are associated with a higher risk for incident AF, there is limited data on the efficacy and safety following cryoablation according to body mass index (BMI) especially in Asians. METHODS AND RESULTS: Using the Korean Heart Rhythm Society Cryoablation registry, a multicentre registry of 12 tertiary hospitals, we analysed AF recurrence and procedure-related complications after cryoablation by BMI (kg/m2) groups (BMI < 18.5, underweight, UW; 18.5-23, normal, NW; 23-25, overweight, OW; 25-30, obese Ⅰ, OⅠ; ≥30, obese Ⅱ, OⅡ). A total of 2648 patients were included (median age 62.0 years; 76.7% men; 55.6% non-paroxysmal AF). Patients were categorized by BMI groups: 0.9% UW, 18.7% NW, 24.8% OW, 46.1% OI, and 9.4% OII. Underweight patients were the oldest and had least percentage of non-paroxysmal AF (33.3%). During a median follow-up of 1.7 years, atrial arrhythmia recurred in 874 (33.0%) patients (incidence rate, 18.9 per 100 person-years). After multivariable adjustment, the risk of AF recurrence was higher in UW group compared with NW group (adjusted hazard ratio, 95% confidence interval; 2.55, 1.18-5.50, P = 0.02). Procedure-related complications occurred in 123 (4.7%) patients, and the risk was higher for UW patients (odds ratio, 95% confidence interval; 2.90, 0.94-8.99, P = 0.07), mainly due to transient phrenic nerve palsy. CONCLUSION: Underweight patients showed a higher risk of AF recurrence after cryoablation compared with NW patients. Also, careful attention is needed on the occurrence of phrenic nerve palsy in UW patients.

Comparison between catheter ablation versus permanent pacemaker implantation as an initial treatment for tachycardia-bradycardia syndrome patients: a prospective, randomized trial.

BACKGROUND: Clinical outcomes after catheter ablation (CA) or pacemaker (PM) implantation for the tachycardia-bradycardia syndrome (TBS) has not been evaluated adequately. We tried to compare the efficacy and safety outcomes of CA and PM implantation as an initial treatment option for TBS in paroxysmal atrial fibrillation (AF) patients. METHODS: Sixty-eight patients with paroxysmal AF and TBS (mean 63.7 years, 63.2% male) were randomized, and received CA (n = 35) or PM (n = 33) as initial treatments. The primary outcomes were unexpected emergency room visits or hospitalizations attributed to cardiovascular causes. RESULTS: In the intention-to-treatment analysis, the rates of primary outcomes were not significantly different between the two groups at the 2-year follow-up (19.8% vs. 25.9%; hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.25-2.20, P = 0.584), irrespective of whether the results were adjusted for age (HR 1.12, 95% CI 0.34-3.64, P = 0.852). The 2-year rate of recurrent AF was significantly lower in the CA group compared to the PM group (33.9% vs. 56.8%, P = 0.038). Four patients (11.4%) in the CA group finally received PMs after CA owing to recurrent syncope episodes. The rate of major or minor procedure related complications was not significantly different between the two groups. CONCLUSION: CA had a similar efficacy and safety profile with that of PM and a higher sinus rhythm maintenance rate. CA could be considered as a preferable initial treatment option over PM implantation in patients with paroxysmal AF and TBS. TRIAL REGISTRATION: KCT0000155.

Variation in Functional Pelvic Tilt in Female Patients Undergoing Total Hip Arthroplasty With Acetabular Dysplasia.

BACKGROUND: As the pelvis is a dynamic structure, the quantification of pelvic tilt (PT) should be done in different hip positions prior to total hip arthroplasty (THA). We sought to investigate functional PT in young female patients undergoing THA and explore the correlation of PT with the extent of acetabular dysplasia. Additionally, we aimed to define the PS-SI (pubic symphysis-sacroiliac joint) index as a PT quantifier on AP pelvis X-ray. METHODS: Pre-THA female patients under the age of 50 years (n = 678) were investigated. Functional PT in 3 positions (supine, standing, and sitting) were measured. Hip parameters including lateral center-edge angle (LCEA), Tönnis angle, head extrusion index (HEI), and femoro-epiphyseal acetabular roof (FEAR) index were correlated to PT values. The PS-SI/SI-SH (sacroiliac joint-sacral height) ratio was also correlated to PT. RESULTS: From the 678 patients, 80% were classified as having acetabular dysplasia. Among these patients, 50.6% were bilaterally dysplastic. The mean functional PT of the entire patient group was 7.4°, 4.1°, and -1.3° in the supine, standing and seated positions. The mean functional PT of the dysplastic group was 7.4°, 4.0°, and -1.2° in the supine, standing and seated positions. The PS-SI/SI-SH ratio was found to be correlated to PT. CONCLUSION: Most of the pre-THA patients had acetabular dysplasia and exhibited anterior PT in the supine and standing positions, most pronounced in the standing position. PT values were comparable between the dysplastic and non-dysplastic group without change with worsening dysplasia. PS-SI/SI-SH ratio can be used to easily characterize PT.

Comparative Bleeding Risk in Patients with Atrial Fibrillation with Cancer versus Without Cancer from Nationwide Prospective Cohort.

Comparison of the bleeding risk for long-term oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF) with and without cancers has been inconsistent. This study aimed to clarify the differences in the bleeding risk in patients with AF with cancers and those without cancers during the long-term OAC.The CODE-AF prospective registry enrolled 5,902 consecutive patients treated for AF at 10 tertiary referral centers in Korea. Of the enrolled patients, 464 (7.8%) were diagnosed with cancers and were followed for all stroke and bleeding events (net composite events).The age, CHA2DS2-VASC, and HAS-BLED scores were similar between AF patients with and without cancers. Male population greatly comprised patients with AF with cancers. They were equally prescribed with direct OAC compared to those without cancers. The incidence rate for clinically relevant nonmajor (CRNM) bleeding events was higher in the patients with AF with cancers than in those without cancers (4.4 per 100 person-years versus 2.8 per 100 person-years, P = 0.023), and net composite events were also more frequent in patients with AF with cancers than in those without cancers (6.4 per 100 person-years versus 4.0 per 100 person-years, P = 0.004). Patients with AF with cancers showed a significantly higher rate of CRNM bleeding (hazard ratio [HR] 1.54, confidence interval [CI] 1.05-2.25, P = 0.002) than those without cancers.Based on the AF cohort, AF with cancers could face a significantly higher risk for CRNM bleeding events in the long-term OAC than those without cancers.

Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial Fibrillation and Prior Gastrointestinal Bleeding.

BACKGROUND AND PURPOSE: Limited data support the benefits of non-vitamin K oral anticoagulants (NOACs) among atrial fibrillation patients with prior gastrointestinal bleeding (GIB). We aimed to evaluate the effectiveness and safety of NOACs compared with those of warfarin among atrial fibrillation patients with prior GIB. METHODS: Oral anticoagulant-naive individuals with atrial fibrillation and prior GIB between January 2010 and April 2018 were identified from the Korean claims database. NOAC users were compared with warfarin users by balancing covariates using the inverse probability of treatment weighting method. The primary outcomes were ischemic stroke, major bleeding, and the composite outcome (combined ischemic stroke and major bleeding). Fatal events from each outcome were evaluated as secondary outcomes. RESULTS: A total of 42 048 patients were included (24 781 in the NOAC group and 17 267 in the warfarin group). The mean time from prior GIB to the initiation of oral anticoagulant was 3.1±2.6 years. After inverse probability of treatment weighting, baseline characteristics were balanced between the two groups (mean age, 72 years; men, 56.8%; and mean CHA2DS2-VASc score, 3.7). Lower risks of ischemic stroke, major bleeding, and the composite outcome were associated with NOAC use than with warfarin use (weighted hazard ratio, 0.608 [95% CI, 0.543-0.680]; hazard ratio, 0.731 [95% CI, 0.642-0.832]; and hazard ratio, 0.661 [95% CI, 0.606-0.721], respectively). For all secondary outcomes, NOACs showed greater risk reductions compared with warfarin. CONCLUSIONS: NOACs were associated with lower risks of ischemic stroke and major bleeding than warfarin among atrial fibrillation patients with prior GIB.

Effect of alcohol consumption on the risk of adverse events in atrial fibrillation: from the COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation (CODE-AF) registry.

AIMS: The aim of this study is to determine the relationship between alcohol consumption and atrial fibrillation (AF)-related adverse events in the AF population. METHODS AND RESULTS: A total of 9411 patients with nonvalvular AF in a prospective observational registry were categorized into four groups according to the amount of alcohol consumption-abstainer-rare, light (<100 g/week), moderate (100-200 g/week), and heavy (≥200 g/week). Data on adverse events (ischaemic stroke, transient ischaemic attack, systemic embolic event, or AF hospitalization including for AF rate or rhythm control and heart failure management) were collected for 17.4 ± 7.3 months. A Cox proportional hazard models was performed to calculate hazard ratios (HRs), and propensity score matching was conducted to validate the results. The heavy alcohol consumption group showed an increased risk of composite adverse outcomes [adjusted hazard ratio (aHR) 1.32, 95% confidence interval (CI) 1.06-1.66] compared with the reference group (abstainer-rare group). However, no significant increased risk for adverse outcomes was observed in the light (aHR 0.88, 95% CI 0.68-1.13) and moderate (aHR 0.91, 95% CI 0.63-1.33) groups. In subgroup analyses, adverse effect of heavy alcohol consumption was significant, especially among patients with low CHA2DS2-VASc score, without hypertension, and in whom ß-blocker were not prescribed. CONCLUSION: Our findings suggest that heavy alcohol consumption increases the risk of adverse events in patients with AF, whereas light or moderate alcohol consumption does not.

Impact of High-Dose Irradiation on Human iPSC-Derived Cardiomyocytes Using Multi-Electrode Arrays: Implications for the Antiarrhythmic Effects of Cardiac Radioablation.

Cardiac radioablation is emerging as an alternative option for refractory ventricular arrhythmias. However, the immediate acute effect of high-dose irradiation on human cardiomyocytes remains poorly known. We measured the electrical activities of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) upon irradiation with 0, 20, 25, 30, 40, and 50 Gy using a multi-electrode array, and cardiomyocyte function gene levels were evaluated. iPSC-CMs showed to recover their electrophysiological activities (total active electrode, spike amplitude and slope, and corrected field potential duration) within 3-6 h from the acute effects of high-dose irradiation. The beat rate immediately increased until 3 h after irradiation, but it steadily decreased afterward. Conduction velocity slowed in cells irradiated with ≥25 Gy until 6-12 h and recovered within 24 h; notably, 20 and 25 Gy-treated groups showed subsequent continuous increase. At day 7 post-irradiation, except for cTnT, cardiomyocyte function gene levels increased with increasing irradiation dose, but uniquely peaked at 25-30 Gy. Altogether, high-dose irradiation immediately and reversibly modifies the electrical conduction of cardiomyocytes. Thus, compensatory mechanisms at the cellular level may be activated after the high-dose irradiation acute effects, thereby, contributing to the immediate antiarrhythmic outcome of cardiac radioablation for refractory ventricular arrhythmias.

Time Course and Risk Factors of New-Onset Complete Atrioventricular Block After Transcatheter Aortic Valve Implantation.

In this study, we aimed to investigate the time course of new-onset complete atrioventricular block (CAVB) and its reversibility after transcatheter aortic valve implantation (TAVI). We analyzed 206 consecutive patients without baseline CAVB who underwent successful TAVI. The incidence of new-onset CAVB was determined to be 12.6% (26/206). Among these patients, 14 recovered from CAVB within 2 weeks (6.8%, 14/206), while the remaining 12 (5.8%, 12/206) underwent permanent pacemaker (PPM) insertion. Among the 12 patients who received the PPM, 4 were able to recover from CAVB within 4 months. Thus, only 8 among 206 patients (3.8%) showed persistent CAVB. Early-onset CAVB on the day of the procedure was the strongest predictor of PPM implantation (OR = 127). The electrocardiographic changes that occurred after TAVI were mostly recovered after 1 month. The most critical procedural factor that predicts CAVB and PPM insertion is the deep implantation (>4 mm) of a big valve (oversizing index >5.9%). In conclusion, the incidence of CAVB after TAVI was estimated to be at 12.6%. Two-thirds of these patients recovered from CAVB within 3 days, resulting in a final rate of persistent CAVB of 4%. To prevent CAVB, we have to implant an appropriate valve type with an optimal size and depth.

Oral Anticoagulation in Asian Patients With Atrial Fibrillation and a History of Intracranial Hemorrhage.

Background and Purpose- Warfarin is associated with a better net clinical benefit compared with no treatment in patients with nonvalvular atrial fibrillation (AF) and history of intracranial hemorrhage (ICH). There are limited data on nonvitamin K antagonist oral anticoagulants (NOACs) in these patients, especially in the Asian population. We aimed to compare the effectiveness and safety of NOACs to warfarin in a large-scale nationwide Asian population with AF and a history of ICH. Methods- Using the Korean Health Insurance Review and Assessment database from January 2010 to April 2018, we identified patients with oral anticoagulant naïve nonvalvular AF with a prior spontaneous ICH. For the comparisons, warfarin and NOAC groups were balanced using propensity score weighting. Ischemic stroke, ICH, composite outcome (ischemic stroke+ICH), fatal ischemic stroke, fatal ICH, death from composite outcome, and all-cause death were evaluated as clinical outcomes. Results- Among 5712 patients with AF with prior ICH, 2434 were treated with warfarin and 3278 were treated with NOAC. Baseline characteristics were well-balanced after propensity score weighting (mean age 72.5 years and CHA2DS2-VASc score 4.0). Compared with warfarin, NOAC was associated with lower risks of ischemic stroke (hazard ratio [HR], 0.77 [95% CI, 0.61-0.97]), ICH (HR, 0.66 [95% CI, 0.47-0.92]), and composite outcome (HR, 0.73 [95% CI, 0.60-0.88]). NOAC was associated with lower risks of fatal stroke (HR, 0.54 [95% CI, 0.32-0.89]), death from composite outcome (HR, 0.53 [95% CI, 0.34-0.81]), and all-cause death (HR, 0.83 [95% CI, 0.69-0.99]) than warfarin. NOAC showed nonsignificant trends toward to reduce fatal ICH compared with warfarin (HR, 0.47 [95% CI, 0.20-1.03]). Conclusions- NOAC was associated with a significant lower risk of ICH and ischemic stroke compared with warfarin. NOAC might be a more effective and safer treatment option for Asian patients with nonvalvular AF and a prior history of ICH.

Temporal trends of catheter ablation for patients with atrial fibrillation: A Korean nationwide population-based study.

INTRODUCTION: Catheter ablation (CA) for atrial fibrillation (AF) is used as a treatment to restore and maintain sinus rhythm in patients with AF. However, limited data exist regarding the temporal trends of AF ablation in Asia. This study aimed to describe the temporal trends of CA for AF in Korean over 11 years. METHODS: The nationwide claims database in Korea was utilized. Patients underwent CA for AF were identified using combinations of diagnostic codes, claims history, and procedure codes. Comorbidities and complications were also identified, and their temporal trends were evaluated. RESULTS: The numbers of patients underwent CA for AF were observed to gradually increased over 11 years (452 patients in 2007 vs. 3035 patients in 2017). Mean age of the study population increased (55.4 in 2007-2010 vs. 58.9 in 2015-2017); and mean CHA2 DS2 -VASc score also increased (1.9 in 2007-2010 vs. 2.2 in 2015-2017). Risks of complications decreased during the study period but risks of all-cause deaths did not changed significantly. Older age, women, hypertension, cerebrovascular accident, chronic obstructive pulmonary disease, chronic kidney disease, general anesthesia, and small procedure volume were independent predictors of complications but, only diabetes and occurrence of any complication were associated with mortality after CA. CONCLUSION: CA for AF has become an increasingly important treatment option. Although the proportion of high-risk patients increased, risks of complications decreased over time. Performing procedure without complications and prompt managements are essential to improve the outcome of the patients with AF underwent CA.

Relationship between dominant frequency, organization index, and left atrial size in patients with atrial fibrillation.

INTRODUCTION: Frequency domain analysis is a methodology for quantifying the organization of atrial fibrillation (AF) pattern to understand the pathophysiology of the electrical mechanism. We aimed to investigate whether the dominant frequency (DF) and organization index (OI) can indicate left atrial (LA) dilatation in patients with AF. METHODS AND RESULTS: This observational, retrospective, single-center cohort study assessed 100 patients with persistent AF. The study population was divided into two groups based on an anterior-posterior LA dimension (LAD of 50 mm) measured by transthoracic echocardiography. The groups were one-to-one propensity score-matched. Frequency domain analysis was performed using signals at leads II and V1 on surface electrocardiogram to calculate the DF and OI. In all patients, the DF was shown to have an inverse relationship with LAD (R = -.369, p < .001 in lead II; R = -.330, p = .001 in lead V1), while the OI was directly associated with LAD (R = .234, p = .190 in lead II; R = .283, p = .004 in lead V1). However, no significant relationship between the signal amplitude and LAD was observed. Compared to patients with LAD ≤ 50 mm, those with LAD > 50 mm had a lower DF (5.057 ± 0.740 vs. 4.542 ± 0.898, p = .002) and higher OI (0.261 ± 0.104 vs. 0.322 ± 0.116, p = .007) in lead V1. These findings were consistent with those found in lead II. CONCLUSION: Patients with persistent AF and a larger LA size had a significantly higher OI and lower DF than those with a smaller LA size. Atrial electrical properties of structural remodeling are associated with increased organization of atrial signals.

Non-Vitamin K Antagonist Oral Anticoagulants in Asian Patients With Supranormal Renal Function.

Background and Purpose- In clinical trials, the reduced efficacy of non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention was reported for patients with nonvalvular atrial fibrillation with a creatinine clearance (CrCl) >95 mL/min compared with that of warfarin. We examined the effectiveness, safety, and net clinical benefit of NOACs compared with warfarin in Asian patients with atrial fibrillation and supranormal renal function. Methods- Using data from the Korean National Health Insurance Service database from January 2014 to December 2016, we included patients with nonvalvular atrial fibrillation with CrCl >80 mL/min. Among these incident oral anticoagulant users with rivaroxaban (n=6297), dabigatran (n=4241), apixaban (n=3395), edoxaban (n=1187), and warfarin (n=9884) were analyzed. Propensity score weighting was used to balance covariates across study groups. Hazard ratios for ischemic stroke, intracranial hemorrhage, gastrointestinal bleeding, major bleeding, all-cause death, and the composite outcome defined as ischemic stroke+intracranial hemorrhage+gastrointestinal bleeding+all-cause death were analyzed using Cox regression analysis with warfarin as the reference. Results- Baseline characteristics were well balanced among all groups (mean age, 66±11 years; 63% were men; mean CHA2DS2-VASc score, 3.0±1.8). Forty-five percent of the patients had CrCl >95 mL/min. Pooled NOACs yielded lower risks of ischemic stroke (hazard ratio, 0.51; 95% CI, 0.43-0.60) and the composite outcome (hazard ratio, 0.64; 95% CI, 0.58-0.70) than warfarin in patients with CrCl >80 mL/min. These benefits were consistent in those with CrCl >95 mL/min. All 4 NOACs reduced the risks of ischemic stroke and the composite outcome in both patients with CrCl >80 mL/min and >95 mL/min. Conclusions- The NOACs showed better effectiveness and safety than warfarin in the patients with atrial fibrillation and supranormal renal function; this was consistently observed for all 4 NOACs and in patients with CrCl >95 mL/min.

Effectiveness and Safety of Contemporary Oral Anticoagulants Among Asians With Nonvalvular Atrial Fibrillation.

Background and Purpose- Limited evidence exists on the effectiveness and safety of warfarin and all 4 available non-vitamin K antagonist oral anticoagulants (NOACs) from current clinical practice in the Asian population with nonvalvular atrial fibrillation. We aimed to evaluate the comparative effectiveness and safety of warfarin and 4 NOACs. Methods- We studied a retrospective nonrandomized observational cohort of oral anticoagulant naïve nonvalvular patients with atrial fibrillation treated with warfarin or NOACs (rivaroxaban, dabigatran, apixaban, or edoxaban) from January 2015 to December 2017, based on the Korean Health Insurance Review and Assessment database. For the comparisons, warfarin to 4 NOACs and NOAC to NOAC comparison cohorts were balanced using the inverse probability of treatment weighting. Ischemic stroke, intracranial hemorrhage, gastrointestinal bleeding, major bleeding, and a composite clinical outcome were evaluated. Results- A total of 116 804 patients were included (25 420 with warfarin, 35 965 with rivaroxaban, 17 745 with dabigatran, 22 177 with apixaban, and 15 496 with edoxaban). Compared with warfarin, all NOACs were associated with lower risks of ischemic stroke, intracranial hemorrhage, gastrointestinal bleeding, major bleeding, and composite outcome. Apixaban and edoxaban showed a lower rate of ischemic stroke compared with rivaroxaban and dabigatran. Apixaban, dabigatran, and edoxaban had a lower rate of gastrointestinal bleeding and major bleeding compared with rivaroxaban. The composite clinical outcome was nonsignificantly different for apixaban versus edoxaban. Conclusions- In this large contemporary nonrandomized Asian cohort, all 4 NOACs were associated with lower rates of ischemic stroke and major bleeding compared with warfarin. Differences in clinical outcomes between NOACs may give useful guidance for physicians to choose drugs to fit their particular patient clinical profile.

Extensive left atrial ablation was associated with exacerbation of left atrial stiffness and dyspnea.

INTRODUCTION: The left atrium (LA), including the pulmonary vein antrum, is the main target of catheter ablation for atrial fibrillation (AF). However, there is a lack of data on the effect of extensive LA ablation on LA stiffness. This study sought to investigate the impact of extensive LA ablation on LA stiffness and dyspnea after the restoration of sinus rhythm. METHODS: In total, 97 patients with AF (80 patients who only underwent pulmonary vein isolation [PVI] and 17 patients who underwent extensive LA ablation) were investigated. Extensive LA ablation was defined as PVI plus at least two sets of LA linear-line ablation. LA stiffness was estimated using the ratio of E/e' to global longitudinal LA strain, as measured by echocardiography. The clinical outcomes we evaluated were AF recurrence and composite dyspnea, which we defined as newly prescribed diuretics or hospitalization for heart failure. RESULTS: Patients were 59.3 ± 10.0 years old on average, and 68 (70.1%) were male. There were no significant differences in baseline characteristics or echocardiographic parameters before ablation between the two groups. After ablation, LA stiffness was higher in the extensive ablation group compared with that in the PVI group (0.9 ± 0.6 vs 0.5 ± 0.3, respectively, P = .017). Multivariable linear regression analysis showed that extensive ablation increased LA stiffness (ß = 0.363, P < .001). AF recurrence was similar in both groups; however, composite dyspnea outcomes were worse in the extensive ablation group (P = .003). CONCLUSION: Extensive LA ablation was associated with a worsening of LA stiffness. This might explain dyspnea despite the successful restoration of sinus rhythm.

Validation of Conventional Thromboembolic Risk Factors in a Korean Atrial Fibrillation Population　- Suggestion for a Novel Scoring System, CHA2DS2-VAK.

BACKGROUND: There is little evidence that focuses on the ethnic variability of clinical risk factors for thromboembolism (TE) in atrial fibrillation (AF). We aimed to investigate the effect of each traditional risk factor in the Korean AF population. Methods and Results: Medical records of 12,876 consecutive patients (aged >18 years) newly diagnosed and followed up with non-valvular AF from 2000 to 2013 were reviewed. TE events, including ischemic stroke and systemic embolism, were investigated for risk factor validation. Among the total of 12,876 patients, 1,390 (10.8%) had TE events. In univariate/multivariate analysis adjusting for clinical factors and antithrombotic medications, traditional risk factors included in the CHA2DS2-VASc scheme showed statistical significance, except for female sex, which was not a predictor of events. Additionally, chronic kidney disease (CKD; hazard ratio 1.62, P<0.001) was shown to be an independent predictor of TE events. Based on the analysis, we developed a novel stratification system, CHA2DS2-VAK, omitting the female sex category and adding CKD. The new scoring system showed greater discrimination in event rates between score 0 and 1 patients. CONCLUSIONS: Female sex was not associated with TE events in a Korean non-valvular AF population. The novel CHA2DS2-VAK scoring system, with substitution of CKD for female sex, might be more appropriate for the Korean population.

Atrial Innervation Patterns of Intrinsic Cardiac Autonomic Nerves.

BACKGROUND: Although ganglionated plexi (GPs) are important in the pathogenesis of arrhythmia, their patterns of atrial innervation have remained unclear. We investigated patterns of GP innervation to cardiac atria and the neuroanatomical interconnections among GPs in an animal model. METHODS: Atrial innervation by GPs was evaluated in 10 mongrel dogs using a retrograde neuronal tracer (cholera toxin subunit B [CTB] conjugated with fluorescent dyes). In Experiment 1, CTB was injected into the atria. In Experiment 2, CTB was injected into the major GP, including the anterior right GP (ARGP), inferior right GP (IRGP), superior left GP (SLGP), and ligament of Marshall (LOM). After 7 days, the GPs were examined for the presence of tracer-positive neurons. RESULTS: GPs in either right or left-side were innervating to both the same and opposite sides of the atrium. In quantitative analysis, right-sided GPs, especially ARGP, showed numerical predominance in atrial innervation. Based on the proportion of CTB-labeled ganglion in each GP, atrial innervation by GPs showed a tendency of laterality. In Experiment 2, CTB that was injected to a particular GP widely distributed in different GP. ARGP projected the largest number of innervating neurons to the IRGP, SLGP and LOM. CONCLUSION: This study demonstrated that GPs project axons widely to both the same and opposite sides of atria. ARGP played a dominant role in atrial innervation. Furthermore, there were numerous neuroanatomical interconnections among GPs. These findings about neuronal innervation and interconnections of GPs could offer useful information for understanding intrinsic cardiac nervous system neuroanatomy.

Increased Risk of Atrial Fibrillation in the Early Period after Herpes Zoster Infection: a Nationwide Population-based Case-control Study.

BACKGROUND: Herpes zoster (HZ) is a chronic inflammatory disease that could result in autonomic dysfunction, often leading to atrial fibrillation (AF). METHODS: From the Korean National Health Insurance Service database of 738,559 subjects, patients newly diagnosed with HZ (n = 30,685) between 2004 and 2011, with no history of HZ or AF were identified. For the non-HZ control group, 122,740 age- and sex-matched subjects were selected. AF development in the first two-years following HZ diagnosis, and during the overall follow-up period were compared among severe (requiring hospitalization, n = 2,213), mild (n = 28,472), and non-HZ (n = 122,740) groups. RESULTS: There were 2,204 (1.4%) patients diagnosed with AF during follow-up, and 825 (0.5%) were diagnosed within the first two years after HZ. The severe HZ group showed higher rates of AF development (6.4 per 1,000 patient-years [PTPY]) compared to mild-HZ group (2.9 PTPY) and non-HZ group (2.7 PTPY). The risk of developing AF was higher in the first two-years after HZ diagnosis in the severe HZ group (10.6 PTPY vs. 2.7 PTPY in mild-HZ group and 2.6 PTPY in non-HZ group). CONCLUSION: Severe HZ that requires hospitalization shows an increased risk of incident AF, and the risk is higher in the first two-years following HZ diagnosis.