Impact of the COVID-19 pandemic on the hospitalizations, time course, presenting symptoms, and mid-term outcomes in patients with myocardial infarctions in a Japanese multi-center registry.

To investigate the impact of the coronavirus disease 2019 (COVID-19) pandemic on myocardial infarctions (MIs), consecutive MI patients were retrospectively reviewed in a multi-center registry. The patient characteristics and 180-day mortality for both ST-segment elevation myocardial infarctions (STEMIs) and non-STEMIs (NSTEMIs) in the after-pandemic period (7 April 2020-6 April 2021) were compared to the pre-pandemic period (7 April 2019-6 April 2020). Inpatients with MIs, STEMIs, and NSTEMIs decreased by 9.5%, 12.5%, and 4.1% in the after-pandemic period. The type of the presenting symptoms (as classified as typical symptoms, atypical symptoms, and out-of-hospital cardiac arrests [OHCAs]) did not differ between the two time periods for both STEMIs and NSTEMIs, while the rate of OHCAs was numerically higher in the after-pandemic period for the STEMIs (12.1% vs. 8.0%, p = 0.30). The symptom-to-admission time (STAT) did not differ between the two time periods for both STEMIs and NSTEMIs, but the door-to-balloon time (DTBT) for STEMIs was significantly longer in the after-pandemic period (83.0 [67.0-100.7] min vs. 70.0 [59.0-88.7] min, p = 0.004). The 180-day mortality did not significantly differ between the two time periods for both STEMIs (15.9% vs. 11.4%, p = 0.14) and NSTEMIs (9.9% vs. 8.0%, p = 0.59). In conclusion, hospitalizations for MIs decreased after the COVID-19 pandemic. Although the DTBTs were significantly longer in the after-pandemic period, the mid-term outcomes for MIs were preserved.

Effect of Catheter Ablation for Atrial Fibrillation in Heart Failure With Mid-Range or Preserved Ejection Fraction　- Pooled Analysis of the AF Frontier Ablation Registry and Hokuriku-Plus AF Registry.

BACKGROUND: A recent randomized trial demonstrated that catheter ablation for atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (EF) is associated with a reduction in death or heart failure. However, the effect of catheter ablation for AF in patients with heart failure with mid-range or preserved EF is unclear.Methods and Results: We screened 899 AF patients (72.4% male, mean age 68.4 years) with heart failure and left ventricular EF ≥40% from 2 Japanese multicenter AF registries: the Atrial Fibrillation registry to Follow the long-teRm Outcomes and use of aNTIcoagulants aftER Ablation (AF Frontier Ablation Registry) as the ablation group (525 patients who underwent ablation) and the Hokuriku-Plus AF Registry as the medical therapy group (374 patients who did not undergo ablation). Propensity score matching was performed in these 2 registries to yield 106 matched patient pairs. The primary endpoint was a composite of cardiovascular death and hospitalization for heart failure. At 24.6 months, the ablation group had a significantly lower incidence of the primary endpoint (hazard ratio 0.32; 95% confidence interval 0.13-0.70; P=0.004) than the medical therapy group. CONCLUSIONS: Compared with medical therapy, catheter ablation for AF in patients with heart failure and mid-range or preserved EF was associated with a significantly lower incidence of cardiovascular death or hospitalization for heart failure.

Trends in Prescribing Antipsychotics for Children and Adolescents in Japan: A Descriptive Epidemiological Study Using a Large-Scale Pharmacy Dataset.

Little is known about antipsychotic prescription patterns among children and adolescents in Japan, particularly in outpatient settings. We investigated the prevalence and trends of antipsychotic prescription for outpatients aged ≤ 17 years receiving a first antipsychotic prescription from 2006 to 2012 based on a large-scale dispensation dataset. Measurements included age, sex, department of diagnosis and treatment, type of prescription (monotherapy or polytherapy), antipsychotic dosage, and concomitant psychotropic drugs. Of the 10,511 patients, 65.1% were aged 13-17 years, and 52.9% were males. Second-generation antipsychotic monotherapy prescriptions increased from 53.8% in 2006 to 78.3% in 2012. Risperidone was the most frequently prescribed antipsychotic, followed by aripiprazole and olanzapine. Approximately 25.0% of patients were prescribed an initial dose less than recommended. Second-generation antipsychotic monotherapy is currently the most frequent prescription pattern among outpatients aged ≤ 17 years receiving an initial antipsychotic prescription.

Impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after catheter ablation of atrial fibrillation: insights from AF frontier ablation registry.

The impact of catheter ablation for atrial fibrillation (AF) on cardiovascular events and mortality is controversial. We investigated the impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after AF ablation from a Japanese multicenter cohort of AF ablation. We investigated 3326 consecutive patients (25.8% female, mean age 63.3 ± 10.3 years) who underwent catheter ablation for AF from the atrial fibrillation registry to follow the long-term outcomes and use of anti coagulants after ablation (AF frontier ablation registry). The primary endpoint was a composite of stroke, transient ischemic attack, cardiovascular events, and all-cause death. During a mean follow-up of 24.0 months, 2339 (70.3%) patients were free from AF after catheter ablation, and the primary composite endpoint occurred in 144 (4.3%) patients. The AF nonrecurrence group had a significantly lower incidence of the primary endpoint (1.8 per 100 person-years) compared with the AF recurrence group (3.0 per 100 person-years, p = 0.003). The multivariate analysis revealed that freedom from AF (hazard ratio 0.61, 95% confidence interval 0.44-0.86, p = 0.005) was independently associated with the incidence of the composite event. In the multicenter cohort of AF ablation, sinus rhythm maintenance after catheter ablation was independently associated with lower rates of major adverse cardiac and cerebrovascular events.

Modified ablation index: a novel determinant of a successful first-pass left atrial posterior wall isolation.

Although a left atrial posterior wall isolation (LAPWI) in addition to a pulmonary vein isolation is a well-accepted option for persistent atrial fibrillation (AF), a complete isolation can be challenging. This study aimed to evaluate the performance of a modified ablation index (AI) (AI/bipolar voltage along the ablation line) for predicting a durable LAPWI. The study included 55 consecutive patients, aged 65 ± 11 years, who underwent an electroanatomic mapping-guided LAPWI of AF. The association between the gaps (first-pass LAPWI failure and/or acute LAPW reconnections), voltage amplitude along the roof and floor lines, and thickness of the LAPW was investigated. Gaps occurred in 22 patients (40%) and in 26 (8%) of the 330 line segments. Gaps were associated with a relatively high bipolar voltage (3.38 ± 1.83 vs. 1.70 ± 1.12 mV, P < 0.0001) and thick LA wall (2.52 ± 1.15 vs. 1.42 ± 0.44 mm, P < 0.0001). A modified AI ≤ 199 AU/mV, bipolar voltage ≥ 2.64 mV, wall thickness ≥ 2.04 mm, and roof ablation line ≥ 43.4 mm well predicted gaps (AUCs: 0.783, 0.787, 0.858, and 0.752, respectively). A high-voltage zone, thick LAPW, and long roof ablation line appeared to be determinants of gaps, and a modified AI ≥ 199 AU/mV along the ablation lines appeared to predict an acute durable LAPWI.

Resetting of atrial tachycardia by a scanned extrastimulus at a downstream site on a multielectrode catheter: a simple diagnostic maneuver for locating the macroreentrant atrial tachycardia circuit.

PURPOSE: Entrainment is a useful method for locating reentrant atrial tachycardia (AT) circuits, but alterations or termination of the AT can derail this process. We assessed whether resetting an upstream site of a neighboring electrode by a scanned extrastimulus at a downstream site (when the upstream tissue was refractory) could diagnose that site within the AT circuit. METHODS: The procedure was applied to 48 ATs with a cycle length (CL) of 238 ± 42 ms (26 common flutters, 8 perimitral flutters, 7 left atrial [LA] roof-dependent AT, 3 LA scar-related macroreentrant ATs, 2 pulmonary vein-gap reentry tachycardias, 1 right atrial scar-related macroreentrant AT, and 1 with an unidentified circuit). Entrainment and scanned extrastimulation were attempted at the cavotricuspid isthmus, LA roof, and mitral isthmus and/or critical AT isthmus. RESULTS: Within the circuit, the post-pacing interval minus the ATCL after entrainment was < 30 ms for all ATs and resetting of the AT cycle by ≥ 5 ms occurred in 94% of the ATs. No ATs were reset by extrastimulation outside the circuit. The positive predictive value of both maneuvers for locating the circuit was 100%, and the negative predictive value of the extrastimulation was similar to that of entrainment (96% vs. 100%, P = 0.25). The incidence of an AT alteration was lower with extrastimulation than with entrainment (1% vs. 9%, P = 0.01). For ATs with a CL < 210 ms, extrastimulation yielded a good diagnostic performance without any AT alterations. CONCLUSION: AT resetting by a scanned extrastimulus is diagnostic and avoids AT alterations.

Current Status and Issues Concerning Magnetic Resonance Imaging in Patients with a Magnetic Resonance Conditional Cardiac Implantable Electrical Device: A Single-center Study.

Objective Following the introduction of magnetic resonance (MR)-conditional cardiac implantable electrical devices (CIEDs), patients with CIEDs have undergone MRI scanning more frequently. As the required settings of MRI equipment for scanning patients with a CIED vary by device, a number of precautions should be taken to allow safe examinations, including the confirmation of conditions and selection of MRI modes appropriate for pacing status in individual patients. In this study, we examined the current status and issues concerning the performance of MRI examinations in patients with an MRI-conditional CIED. Method and Results We reviewed a total of 262 MRI scans. The most common site of MRI scanning was the head, followed by the spine, abdomen, and heart in order. Regarding the MRI mode, DOO was most often used, followed by OFF, AOO, and finally VOO mode, to maintain atrioventricular synchrony. Although no obvious adverse events were observed related to MRI scanning, there were several cases encountered that might have been predisposed to a significant incident or in which the patient's intrinsic pulse rates or subjective symptoms changed before and during scanning. Conclusion As MRI is a very useful diagnostic tool for cerebrovascular diseases and orthopedic disorders, the demand for MRI scanning is high when treating these areas. Although MRI scanning in patients with MR-conditional devices was performed without any adverse events, there were incidents that could have potentially led to major harm. This highlights the importance of confirming the appropriate MRI mode is being used before scanning and monitoring patients during scanning.

Comprehensive assessment of left atrial and ventricular remodeling in paroxysmal atrial fibrillation by the cardiovascular magnetic resonance myocardial extracellular volume fraction and feature tracking strain.

Atrial fibrillation (AF) is a progressive disease that starts with structural or functional changes in the left atrium and left ventricle, and evolves from paroxysmal toward sustained forms. Early detection of structural or functional changes in the left atrium and left ventricle in the paroxysmal stage could be useful for identifying a higher risk of progression to persistent AF and future cardio-cerebrovascular events. The aim of this study was to test the hypothesis that the feature tracking (FT) left atrial (LA) strain and left ventricular (LV) extracellular volume fraction (ECV) derived from cardiovascular magnetic resonance (CMR) could detect early changes in remodeling of the left atrium and ventricle in the paroxysmal AF (PAF) stage. The participants were comprised of 106 PAF patients (age, 66.1 ± 10.7 years; 66% male) who underwent clinical CMR before pulmonary vein isolation and 20 control subjects (age, 68.3 ± 8.6 years; 55% male). The CMR-FT LA strain/phasic function and LV-ECV were compared between the PAF and control groups. The total and passive LA empty fraction (LAEF) and LA strain (corresponding to LA reservoir and conduit function) were decreased in the PAF group as compared to the control group. However, active LAEF (corresponding to the LA booster pump function) did not differ significantly between the PAF group (33.9 ± 10.9%) and control group (37.9 ± 13.3%, p = 0.15), while the active LA strain (corresponding to the LA booster pump function) was significantly decreased in the PAF group (11.4 ± 4.3 vs. 15.2 ± 5.6%, p = 0.002). The LV-ECV was significantly greater in the PAF group (28.7 ± 2.8%) than control group (26.6 ± 2.0%, p = 0.002). In the PAF group, the LV-ECV correlated significantly with the E/e' and LA volume index. Regarding the LA strain, correlations were seen between the LV-ECV and both the reservoir function and conduit function. CMR-FT LA strain in combination with the LV-ECV in a single clinical study offers a potential imaging marker that identifies LA/LV remodeling including subtle LA booster pump dysfunction undetectable by the conventional booster pump LAEF in the PAF stage.

Formation of low-voltage zones on the anterior left atrial wall due to mechanical compression by the ascending aorta.

BACKGROUND: Although low-voltage zones (LVZs) in the left atrium (LA) are considered arrhythmogenic substrates in some patients with atrial fibrillation (AF), the pathophysiologic factors responsible for LVZ formations remain unclear. OBJECTIVE: To elucidate the anatomical relationship between the LA and ascending aorta responsible for anterior LA wall remodeling. METHODS: We assessed the relationship between existence of LVZs on the anterior LA wall and the three-dimensional computed tomography image measurements in 102 patients who underwent AF ablation. RESULTS: Twenty-nine patients (28%) had LVZs grearer than 1.0 cm2 on the LA wall in the LA-ascending aorta contact area (LVZ group); no LVZs were seen in the other 73 patients (no-LVZ group). The LVZ group (vs. no-LVZ group) had a smaller aorta-LA angle (21.0 ± 7.7° vs. 24.9 ± 7.1°, p = .015), greater aorta-left-ventricle (LV) angle (131.3 ± 8.8° vs. 126.0 ± 7.9°; p = .005), greater diameter of the noncoronary cusp (NCC; 20.4 ± 2.2 vs. 19.3 ± 2.5 mm; p = .036), thinner LA wall-thickness adjacent to the NCC (2.3 ± 0.7 vs. 2.8 ± 0.8 mm; p = .006), and greater cardiothoracic ratio (percentage of the area in the thoracic area, 40.1 ± 7.1% vs. 35.4 ± 5.7%, p < .001). The aorta-LA angle correlated positively with the patients' body mass index (BMI), and the aorta-LV angle correlated negatively with the body weight and BMI. CONCLUSION: Deviation of the ascending aorta's course and distention of the NCC appear to be related to the development of LA anterior wall LVZs in the LA-ascending aorta contact area. Mechanical pressure exerted by extracardiac structures on the LA along with the limited thoracic space may contribute to the development of LVZs associated with AF.

Effect of obesity and epicardial fat/fatty infiltration on electrical and structural remodeling associated with atrial fibrillation in a novel canine model of obesity and atrial fibrillation: A comparative study.

BACKGROUND: How obesity and epicardial fat influence atrial fibrillation (AF) is unknown. METHODS: To investigate the effect of obesity/epicardial fat on the AF substrate, we divided 20 beagle dogs of normal weight into four groups (n = 5 each): one of the four groups (Obese-rapid atrial pacing [RAP] group) served as a novel canine model of obesity and AF. The other three groups comprised dogs fed a standard diet without RAP (Control group), dogs fed a high-fat diet without RAP (Obese group), or dogs fed a standard diet with RAP (RAP group). All underwent electrophysiology study, and hearts were excised for histopathologic and fibrosis-related gene expression analyses. RESULTS: Left atrial (LA) pressure was significantly higher in the Obese group than in the Control, RAP, and Obese-RAP groups (23.4 ± 6.9 vs. 11.4 ± 2.1, 11.9 ± 6.4, and 13.5 ± 2.9 mmHg; p = .005). The effective refractory period of the inferior PV was significantly shorter in the RAP and Obese-RAP groups than in the Control group (p = .043). Short-duration AF was induced at greatest frequency in the Obese-RAP and Obese groups (p < .05). Epicardial fat/Fatty infiltration was greatest in the Obese-RAP group, and greater in the Obese and RAP groups than in the Control group. %interstitial fibrosis/fibrosis-related gene expression was significantly greater in the Obese-RAP and RAP groups (p < .05). CONCLUSIONS: Vulnerability to AF was associated with increased LA pressure and increased epicardial fat/fatty infiltration in our Obese group, and with increased epicardial fat/fibrofatty infiltration in the RAP and Obese-RAP groups. These may explain the role of obesity/epicardial fat in the pathogenesis of AF.

Clinical outcomes of ablation versus non-ablation therapy for atrial fibrillation in Japan: analysis of pooled data from the AF Frontier Ablation Registry and SAKURA AF Registry.

Whether ablation for atrial fibrillation (AF) is, in terms of clinical outcomes, beneficial for Japanese patients has not been clarified. Drawing data from 2 Japanese AF registries (AF Frontier Ablation Registry and SAKURA AF Registry), we compared the incidence of clinically relevant events (CREs), including stroke/transient ischemic attack (TIA), major bleeding, cardiovascular events, and death, between patients who underwent ablation (n = 3451) and those who did not (n = 2930). We also compared propensity-score matched patients (n = 1414 in each group). In propensity-scored patients who underwent ablation and those who did not, mean follow-up times were 27.2 and 35.8 months, respectively. Annualized rates for stroke/TIA (1.04 vs. 1.06%), major bleeding (1.44 vs. 1.20%), cardiovascular events (2.15 vs. 2.49%) were similar (P = 0.96, 0.39, and 0.35, respectively), but annualized death rates were lower in the ablation group than in the non-ablation group (0.75 vs.1.28%, P = 0.028). After multivariate adjustment, the risk of CREs was statistically equivalent between the ablation and non-ablation groups (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.71-1.11), but it was significantly low among patients who underwent ablation for paroxysmal AF (HR 0.68 [vs. persistent AF], 95% CI 0.49-0.94) and had a CHA2DS2-VASc score < 3 (HR 0.66 [vs. CHA2DS2-VASc score ≥ 3], 95% CI 0.43-0.98]). The 2-year risk reduction achieved by ablation may be small among Japanese patients, but AF ablation may benefit those with paroxysmal AF and a CHA2DS2-VASc score < 3.

Clinical Outcomes of Off-Label Underdosing of Direct Oral Anticoagulants After Ablation for Atrial Fibrillation.

Direct oral anticoagulants (DOACs) are sometimes prescribed at off-label under-doses for patients who have undergone ablation for atrial fibrillation (AF). This practice may be an attempt to balance the risk of bleeding against that of stroke or AF recurrence.We examined outcomes of 1163 patients who continued use of a DOAC after ablation. The patients were enrolled in a large (3530 patients) multicenter registry in Japan. The study patients were classified as 749 (64.4%) appropriate standard-dose DOAC users, 216 (18.6%) off-label under-dose DOAC users, and 198 (17.0%) appropriate low-dose DOAC users.Age and CHA2DS2-VASc scores differed significantly between DOAC dosing regimens, with patients given an appropriate standard-dose being significantly younger (63.3 ± 9.4 versus 64.8 ± 9.5 versus 73.2 ± 6.8 years, P < 0.0001) and lower (2.1 ± 1.5 versus 2.4 ± 1.6 versus 3.4 ± 1.4, P < 0.0001) than those given an off-label under-dose or an appropriate low-dose. During the median 19.0-month follow-up period, the AF recurrence rate was similar between the appropriate standard-dose and off-label under-dose groups but relatively low in the appropriate low-dose group (42.5% versus 41.2% versus 35.4%, P = 0.08). Annualized rates of thromboembolic events, major bleeding, and death from any cause were 0.47%, 0.70%, and 0.23% in the off-label under-dose group, while those rates were 0.74%, 0.73%, and 0.65% in the appropriate standard-dose, and 1.58%, 2.12%, and 1.57% in the appropriate low-dose groups.In conclusion, the clinical adverse event rates for patients on an off-label under-dose DOAC regimen after ablation, predicated on careful patient evaluations, was not high as seen with that of patients on a standard DOAC dosing regimen.

Hot balloon versus cryoballoon ablation for persistent atrial fibrillation: Lesion area, efficacy, and safety.

INTRODUCTION: The clinical efficacy and safety of hot balloon ablation (HBA) for the treatment of persistent AF (PerAF) remain unclear. We aimed to evaluate the clinical efficacy and safety of HBA versus cryoballoon ablation (CBA) as a treatment for PerAF. METHODS: Of 195 consecutive patients who underwent initial catheter ablation for PerAF (AF lasting for longer than 7 days but shorter than 12 months), 158 propensity score-matched (79 HBA and 79 CBA) patients were included in our retrospective study. All patients who underwent HBA received applications of energy to the upper posterior LA wall with a larger balloon in addition to single shots to each pulmonary vein (PV) ostium, whereas those who underwent CBA received simple single-shot applications. The electrically isolated surface area (ISA), including the PV antrum and part of the posterior LA wall, was assessed by high-resolution mapping. RESULTS: The success of the PV isolation with balloon shots alone did not differ between HBA and CBA (81% vs. 85%; p = .52). The ISA was generally wide in both groups and significantly larger in the HBA group than in the CBA group (61 ± 16% vs. 51 ± 12%; p < .001). The incidence of procedure-related complications did not differ significantly (HBA 4% vs. CBA 1%; p = .62) nor did the arrhythmia recurrence rate (HBA 11% vs. CBA 18% at 18 months; p = .26). CONCLUSION: Despite the difference in protocols, HBA and CBA performed for PerAF appear comparable in terms of wide antral lesion creation, clinical efficacy, and safety. Further prospective studies, based on a unified methodology, are needed.

Effective Pacing Intervention by Closed-loop Stimulation Using a Coronary Vein Lead in a Post-tricuspid Valve Replacement Patient.

To avoid the negative effects associated with pacing, pacemakers are designed to achieve a pacing cadence as close to physiological pacing as possible. In closed-loop stimulation (CLS; a type of rate-responsive functionality used in pacemakers), the changes in impedance (which correlates with the contractility of the myocardium around the lead tip electrode) are tracked, and the paced heart rate is adjusted accordingly. We herein report a case in which we implanted a pacemaker in a post-tricuspid valve replacement patient. A ventricular lead positioned in the coronary vein exhibited good CLS functionality, and the patient's dizziness and heart failure improved.

Optimal diameter of the pulmonary vein ostium for second-generation 28-mm cryoballoon ablation of atrial fibrillation.

BACKGROUND: Large pulmonary veins (PVs) have the risk of excessive cooling when the cryoballoon is moved into them, whereas smaller PVs may not be isolated because of insufficient balloon-tissue contact. We previously reported that the effective nadir balloon temperature (NBT) was <- 44°C for predicting early PV reconnections. However, the ideal PV and left atrial (LA) diameters for cooling temperatures during cryoballoon ablation (CBA) are unknown. METHODS: We measured the PV ostium (PVos) and LA diameters on computed tomography images in 71 atrial fibrillation patients who underwent a 28-mm CBA. We defined -60°C ≤ NBT <- 44°C as the optimal NBT. The optimal PVos diameters and elliptical area were determined using the receiver operating characteristic curve cutoff values for the optimal NBT. RESULTS: The maximum PVos diameter (PVmax), minimum PVos diameter (PVmin), and PV elliptical area correlated negatively with the NBT (PVmax: r = -.34, P < .0001; PVmin: r = -.41, P < .0001; PV elliptical area: r = -.41, P < .0001). Based on the NBT-derived definition, the optimal PVmax, PVmin, and PV elliptical area were 19 < PVmax ≤ 21 mm, 14 < PVmin ≤ 16 mm, and 186.83 < PV elliptical area ≤ 254.34 mm2 , respectively. In addition, a positive correlation between the LA longitudinal diameter and NBT was observed in the right superior PV (r = .34, P = .004), and the LA transverse diameter correlated inversely with the NBT in the left inferior PV (r = -.34, P = .004). CONCLUSIONS: We identified the optimal PV diameters and elliptical area to establish the optimal NBT during the second-generation 28-mm CBA. These data will help for the preclinical judgment for a successful CBA.

Is Vagal Response During Left Atrial Ganglionated Plexi Stimulation a Normal Phenomenon?: Comparison Between Patients With and Without Atrial Fibrillation.

BACKGROUND: Ganglionated plexi (GPs) play an important role in both the initiation and maintenance of atrial fibrillation (AF). GPs can be located by using continuous high-frequency stimulation (HFS) to elicit a vagal response, but whether the vagal response phenomenon is common to patients without AF is unknown. METHODS: HFS of the left atrial GPs was performed in 42 patients (aged 58.0±10.2 years) undergoing ablation for AF and 21 patients (aged 53.2±12.8 years) undergoing ablation for a left-sided accessory pathway. The HFS (20 Hz, 25 mA, 10-ms pulse duration) was applied for 5 seconds at 3 sites within the presumed anatomic area of each of the 5 major left atrial GPs (for a total of 15 sites per patient). We defined vagal response to HFS as prolongation of the R-R interval by >50% in comparison to the mean pre-HFS R-R interval averaged over 10 beats and active-GP areas as areas in which a vagal response was elicited. RESULTS: Overall, more active-GP areas were found in the AF group patients than in the non-AF group patients, and at all 5 major GPs, the maximum R-R interval during HFS was significantly prolonged in the AF patients. After multivariate adjustment, association was established between the total number of vagal response sites and the presence of AF. Conclusions The significant increase in vagal responses elicited in patients with AF compared with responses in non-AF patients suggests that vagal responses to HFS reflect abnormally increased GP activity specific to AF substrates.

Current Status and Clinical Outcomes of Oral Anticoagulant Discontinuation After Ablation for Atrial Fibrillation in Japan　- Findings From the AF Frontier Ablation Registry.

BACKGROUND: The safety of discontinuing oral anticoagulant (OAC) after ablation for atrial fibrillation (AF) in Japanese patients has not been clarified.Methods and Results:A study based on the Atrial Fibrillation registry to Follow the long-teRm Outcomes and use of aNTIcoagulants aftER Ablation (AF Frontier Ablation Registry) was conducted. Data were collected from 3,451 consecutive patients (74.1% men; age, 63.3±10.3 years) who had undergone AF ablation at any of 24 cardiovascular centers in Japan between August 2011 and July 2017. During a 20.7-month follow-up period, OAC therapy was discontinued in 1,836 (53.2%) patients; 51 patients (1.5%) suffered a stroke/transient ischemic attack (TIA), 71 (2.1%) suffered major bleeding, and 36 (1.0%) died. Patients in whom OAC therapy was discontinued were significantly younger than those in whom OACs were continued, and their CHA2DS2-VASc scores were significantly lower. The incidences of stroke/TIA, major bleeding, and death were significantly lower among these patients. Upon multivariate adjustment, stroke events were independently associated with relatively high baseline CHA2DS2-VASc scores but not with OAC status. CONCLUSIONS: Although the incidences of stroke/TIA, major bleeding, and death were relatively low among patients for whom OAC therapy was discontinued, stroke/TIA occurrence was strongly associated with a high baseline stroke risk rather than with OAC status. Thus, discontinuation of OAC therapy requires careful consideration, especially in patients with a high baseline stroke risk.

Adverse Clinical Events during Long-Term Follow-Up After Catheter Ablation of Atrial Fibrillation.

Pulmonary vein isolation (PVI) of atrial fibrillation (AF) can reduce the AF burden and, potentially, reduce the long-term risk of strokes and death. However, it remains unclear whether anticoagulants can be stopped after PVI because of post-ablation AF recurrence in some patients. This study aimed to investigate the discontinuation rate of anticoagulants and long-term incidence of strokes after PVI.We enrolled 512 consecutive Japanese patients with AF (mean age, 63.4 ± 10.4 years; 123 women; 234 with non-paroxysmal AF; CHADS2 score/CHA2DS2-VASC score, 1.32 ± 1.12/2.21 ± 1.54) who underwent PVI between 2012 and 2015. During a 28.0 ± 17.1 -month follow-up, anticoagulants were terminated in 230 (44.9%) of the 512 patients, AF recurred in 200 (39.1%), and 10 (1.95%) suffered from a stroke. Death occurred in 5 (0.98%) patients. Although the incidence of strokes, by a Kaplan-Meier analysis, was similar, the incidence of death was lower (Hazard ratio 0.37, 95% confidence interval 0.12-0.93, P = 0.041) in the AF ablation group than the control group without ablation after 1:1 propensity score matching (the control data was derived from 2,986 patients in the SAKURA AF Registry, a large-cohort AF registry).Anticoagulants were discontinued in nearly half the patients who underwent AF ablation; of these, 39.1% experienced AF recurrences, 1.95% suffered from strokes, and 0.98% died, but the risk of death after AF ablation appeared to be lower than that in a propensity score-matched control group without ablation during long-term follow-up.

Electrophysiologic and anatomic factors predictive of a need for touch-up radiofrequency application for complete pulmonary vein isolation: Comparison between hot balloon- and cryoballoon-based ablation.

INTRODUCTION: Although electrophysiologic and anatomic factors associated with the need for touch-up radiofrequency (RF) applications after cryoballoon ablation (CBA) for atrial fibrillation (AF) have been well described, those associated with the need for such touch-up after hot balloon ablation (HBA) have not. We aimed to identify factors predictive of the need for touch-up applications following HBA. METHODS: Anatomic and electrophysiologic factors predictive of the need for touch-up RF ablation were compared between 46 propensity score-matched pairs of patients who underwent HBA or CBA for AF. RESULTS: Touch-up RF ablation was more frequently required after HBA than after CBA (57% vs 30%, respectively; P = .01), and mostly at the anterior aspect of the left superior pulmonary vein (LSPV) carina after HBA (35%) but at the inferior aspect of the right inferior PV (RIPV) after CBA (71%). Post HBA touch-up was associated with male gender, a CHA 2 DS 2 -VASc score ≤ 2, PV-left atrial bipolar voltage ≥ 1.35 mV, and PV trunk length ≥ 24.0 mm; post CBA touch-up associated with a history of heart failure. CONCLUSION: Following balloon ablation for AF, there may be a need for touch-up applications, especially at the LSPV ridge after HBA but at the RIPV after CBA. It may behoove operators to expect a need for touch-up following HBA when patients are male, have a CHA2 DS 2 -VASc score ≤ 2 points, when PV-LA bipolar voltage is ≥ 1.35 mV, or when the PV trunk is ≥ 24.0 mm or following CBA when there is a history of heart failure.