Impact of Left Atrial Appendage Flow Velocity on Thrombus Resolution and Clinical Outcomes in Patients with Atrial Fibrillation and Silent Left Atrial Thrombi: Insights from the LAT Study

AIMS

Blood stasis is crucial in developing left atrial (LA) thrombi. LA appendage peak flow velocity (LAAFV) is a quantitative parameter for estimating thromboembolic risk. However, its impact on LA thrombus resolution and clinical outcomes remains unclear.

METHODS AND RESULTS

The LAT study was a multicenter observational study investigating patients with atrial fibrillation (AF) and silent LA thrombi detected by transesophageal echocardiography (TEE). Among 17,436 TEE procedures for patients with AF, 297 patients (1.7%) had silent LA thrombi. Excluding patients without follow-up examinations, we enrolled 169 whose baseline LAAFV was available. Oral anticoagulation use increased from 85.7% at baseline to 97.0% at the final follow-up (p < 0.001). During 1-year, LA thrombus resolution was confirmed in 130 (76.9%) patients within 76 (34-138) days. Conversely, 26 had residual LA thrombi, 8 had thromboembolisms, and 5 required surgical removal. These patients with failed thrombus resolution had lower baseline LAAFV than those with successful resolution (18.0 [15.8-22.0] vs. 22.2 [17.0-35.0], p = 0.003). Despite limited predictive power (area under the curve, 0.659; p = 0.001), LAAFV ≤20.0 cm/s (best cutoff) significantly predicted failed LA thrombus resolution, even after adjusting for potential confounders (odds ratio, 2.72; 95% confidence interval, 1.22-6.09; p = 0.015). The incidence of adverse outcomes including ischemic stroke/systemic embolism, major bleeding, or all-cause death was significantly higher in patients with reduced LAAFV than in those with preserved LAAFV (28.4% vs. 11.6%, log-rank p = 0.005).

CONCLUSIONS

Failed LA thrombus resolution was not rare in patients with AF and silent LA thrombi. Reduced LAAFV was associated with failed LA thrombus resolution and adverse clinical outcomes.

Atrial Functional Substrates for the Prediction of Atrial Fibrillation Recurrence After Pulmonary Vein Isolation

Low-voltage areas have been used as atrial structural substrates in estimating fibrotic degeneration in patients with atrial fibrillation (AF). The high-resolution maps obtained by recently developed mapping catheters allow the visualization of several functional abnormalities. We investigated the association between left atrial (LA) functional abnormal findings on a high-resolution substrate map and AF recurrence in patients who underwent pulmonary vein isolation without any additional LA substrate ablation. This observational study included 100 consecutive patients who underwent second ablation for AF (paroxysmal, 48%; persistent, 52%). Patients with extra-pulmonary-vein LA substrate ablation during the initial and second ablation were excluded. LA mapping was performed using a 64-pole mini-basket catheter on the RHYTHMIA mapping system (Boston Scientific, Marlborough [Cambridge] Massachusetts). Patients were followed for 2 years. AF recurrence developed in 39 (39%) patients. On the high-resolution substrate map, AF recurrence was associated with the presence of the following findings: low-voltage areas (<1.0 mV, >5 cm2; hazard ratio [HR] = 2.53; 95% confidence interval [CI] = 1.30 to 4.93; p <0.006), fractionated-electrogram areas (≥5 peaks, >5 cm2; HR = 2.15, 95% CI = 1.10 to 4.19; p = 0.025), LA conduction time of >130 ms (HR = 3.11, 95% CI = 1.65 to 5.88, p <0.0001), deceleration zone (≥5 isochrones/cm2; HR = 1.97, 95% CI = 1.04 to 3.37, p = 0.039), and multiple septal break-out points (HR = 3.27, 95% CI = 1.50 to 7.16, p = 0.003). Accumulation of these risk factors increased AF recurrence in a stepwise manner, with an HR = 1.90, 95% CI = 1.44 to 2.52, p <0.00001 for each additional risk factor. In conclusion, a high-resolution map revealed new LA functional substrates associated with AF recurrence. Implementation of functional substrates may improve the prediction of AF recurrence after ablation, and possibly aid the development of tailored AF ablation strategies.

Initial results of transcatheter modification of left atrial appendage by obliteration with device in patients with nonvalvular atrial fibrillation: Real-world data from the TERMINATOR registry

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) has increased for those who need alternative to long-term anticoagulation with non-valvular atrial fibrillation (NVAF).

METHODS AND RESULTS

From September 2019, after initiating WATCHMAN (Boston Scientific, Maple Grove, MN, USA) device implantation, we established Transcatheter Modification of Left Atrial Appendage by Obliteration with Device in Patients from the NVAF (TERMINATOR) registry. Utilizing 729 patients' data until January 2022, we analyzed percutaneous LAAC data regarding this real-world multicenter prospective registry. A total of 729 patients were enrolled. Average age was 74.9 years and 28.5 % were female. Paroxysmal AF was 37.9 % with average CHADS2 3.2, CHA2DS2-VASc 4.7, and HAS-BLED score of 3.4. WATCHMAN implantation was successful in 99.0 %. All-cause deaths were 3.2 %, and 1.2 % cardiovascular or unexplained deaths occurred during follow-up [median 222, interquartile range (IQR: 93-464) days]. Stroke occurred in 2.2 %, and the composite endpoint which included cardiovascular or unexplained death, stroke, and systemic embolism were counted as 3.4 % [median 221, (IQR: 93-464) days]. Major bleeding defined as BARC type 3 or 5 was seen in 3.7 %, and there was 8.6 % of all bleeding events in total [median 219, (IQR: 93-464) days].

CONCLUSIONS

These preliminary data demonstrated percutaneous LAAC with WATCHMAN device might have a potential to reduce stroke and bleeding events for patients with NVAF. Further investigation is mandatory to confirm the long-term results of this strategy using this transcatheter local therapy instead of life-long systemic anticoagulation.

Impact of diabetes mellitus and poor glycemic control on the prevalence of left atrial low-voltage areas and rhythm outcome in patients with atrial fibrillation ablation

INTRODUCTION

Left atrial low-voltage areas (LVAs) are known to be correlated with atrial scarring and atrial fibrillation (AF) recurrence after ablation. However, the association between LVAs and glycemic status before ablation has not been fully clarified. The purpose of this study was to investigate associations among the prevalence of diabetes mellitus (DM), glycemic control, and the prevalence of LVAs in patients with AF ablation.

METHODS

In total, 912 (age, 68 ± 10 years; female, 299 [33%]; persistent AF, 513 [56%]) consecutive patients who underwent initial AF ablation were included. A preprocedure glycated hemoglobin A1c (HbA1c) ≥7% was set as the cutoff for poor glycemic control in patients with DM. LVAs were defined as areas with a bipolar voltage of <0.5 mV covering ≥5 cm2 of left atrium.

RESULTS

LVAs existed in 208 (23%) patients, and 168 (18%) patients had DM. LVAs were found more frequently in patients with DM and poor glycemic control. On multivariate analysis, DM with HbA1c ≥7% was an independent predictor of LVAs (odds ratio, 3.3; 95% confidence interval: 1.6-6.7; p = .001). In patients with LVAs, freedom from AF recurrence during the 24-month study period was significantly lower in patients who had DM with HbA1c ≥7% than in those without DM (37.9% vs. 54.7%, p = .02).

CONCLUSION

In patients with AF ablation, LVAs were found more frequently in patients with DM and poor glycemic control. DM with HbA1c ≥7% was an independent predictor of LVAs.

Prognostic impact of atrial cardiomyopathy: Long-term follow-up of patients with and without low-voltage areas following atrial fibrillation ablation

BACKGROUND

Atrial cardiomyopathy is known as an underlying pathophysiological factor in the majority of patients with atrial fibrillation (AF). Left atrial low-voltage areas (LVAs) are reported to coincide with fibrosis and likely represent atrial cardiomyopathy.

OBJECTIVE

The purpose of this study was to delineate differences in the long-term prognosis of patients stratified by the size of LVAs.

METHODS

This observational study included 1488 consecutive patients undergoing initial ablation for AF. LVAs were defined as regions with a bipolar peak-to-peak voltage <0.50 mV. The total study population was divided into 3 groups stratified by LVA size: patients with no LVAs (n = 1136); those with small (<20 cm2) LVAs (n = 250) LVAs; and those with extensive (≥20 cm2) LVAs (n = 102). Composite endpoints of death, heart failure, and stroke were followed for up to 5 years.

RESULTS

Composite endpoints developed in 105 of 1488 patients (7.1%), and AF recurrence occurred in 410 (27.6%). Composite endpoints developed more frequently in the order of patients with extensive LVAs (19.1%), small LVAs (10.8%), and no LVAs (5.1%) (P for trend <.0001). Multivariable analysis revealed that LVA presence was independently associated with higher incidence of composite endpoints, irrespective of AF recurrence (modified hazard ratio 1.73; 95% confidence interval 1.13-2.64; P = .011) CONCLUSION: LVA presence and its extent both were associated with poor long-term composite endpoints of death, heart failure, and stroke, irrespective of AF recurrence or other confounders. Underlying atrial cardiomyopathy seems to define a poor prognosis after AF ablation.

Duration of atrial fibrillation persistence: implications for recurrence risk after catheter ablation and efficacy of additional substrate ablation

BACKGROUND

The optimal duration of atrial fibrillation (AF) persistence for predicting poor outcomes after catheter ablation of long-standing AF (LsAF) and the best ablation strategy for these patients remain unclear.

OBJECTIVE

We aimed to assess the impact of the duration of AF persistence on outcomes after catheter ablation of AF.

METHODS

We analyzed the Efficacy of Pulmonary Vein Isolation Alone in Patients with Persistent Atrial Fibrillation (EARNEST-PVI) trial data comparing pulmonary vein isolation (PVI) alone (PVI-alone) with additional linear ablation or defragmentation (PVI-plus) in persistent AF (PerAF). Patients who received catheter ablation by contact force-sensing catheter were enrolled in the study. In patients with LsAF, the optimal cutoff duration of AF persistence was evaluated. With use of the threshold, patients with LsAF were divided into 2 groups and compared with PerAF <1 year for arrhythmia-free survival after a 3-month blanking period.

RESULTS

The optimal cutoff duration was 2.4 years. Of 458 patients, arrhythmia-free survival rates for LsAF 1-2.4 years were comparable to those of PerAF (hazard ratio [HR], 1.01; 95% CI, 0.67-1.52). However, LsAF >2.4 years had a higher recurrence risk than PerAF (HR, 2.22; 95% CI, 1.42-3.47). In LsAF >2.4 years, the PVI-plus strategy showed advantages over the PVI-alone strategy (HR, 0.36; 95% CI, 0.14-0.89). However, the interaction effect between LsAF 1-2.4 years and LsAF >2.4 years did not reach statistical significance (P = .116).

CONCLUSION

Whereas LsAF 1-2.4 years has similar outcomes to those of PerAF, LsAF >2.4 years was linked to higher arrhythmia recurrence risks. For LsAF >2.4 years, the PVI-plus strategy showed a potential to be superior to the PVI-alone strategy.

Uplift modeling to identify patients who require extensive catheter ablation procedures among patients with persistent atrial fibrillation

Identifying patients who would benefit from extensive catheter ablation along with pulmonary vein isolation (PVI) among those with persistent atrial fibrillation (AF) has been a subject of controversy. The objective of this study was to apply uplift modeling, a machine learning method for analyzing individual causal effect, to identify such patients in the EARNEST-PVI trial, a randomized trial in patients with persistent AF. We developed 16 uplift models using different machine learning algorithms, and determined that the best performing model was adaptive boosting using Qini coefficients. The optimal uplift score threshold was 0.0124. Among patients with an uplift score ≥ 0.0124, those who underwent extensive catheter ablation (PVI-plus) showed a significantly lower recurrence rate of AF compared to those who received only PVI (PVI-alone) (HR 0.40; 95% CI 0.19-0.84; P-value = 0.015). In contrast, among patients with an uplift score < 0.0124, recurrence of AF did not significantly differ between PVI-plus and PVI-alone (HR 1.17; 95% CI 0.57-2.39; P-value = 0.661). By employing uplift modeling, we could effectively identify a subset of patients with persistent AF who would benefit from PVI-plus. This model could be valuable in stratifying patients with persistent AF who need extensive catheter ablation before the procedure.

Clinical impact of left atrial remodeling pattern in patients with atrial fibrillation: Comparison of volumetric, electrical, and combined remodeling

INTRODUCTION

Atrial fibrillation (AF) is accompanied by various types of remodeling, including volumetric enlargement and histological degeneration. Electrical remodeling reportedly reflects histological degeneration.

PURPOSE

To clarify the differences in determinants and clinical impacts among types of remodeling.

METHODS

This observational study included 1118 consecutive patients undergoing initial ablation for AF. Patients were divided into four groups: minimal remodeling (left atrial volume index [LAVI] < mean value and no low-voltage area [LVA], n = 477); volumetric remodeling (LAVI ≥ mean value and no LVA, n = 361); electrical remodeling (LAVI < mean value and LVA presence, n = 96); and combined remodeling (LAVI ≥ mean value and LVA presence, n = 184). AF recurrence and other clinical outcomes were followed up for 2 and 5 years, respectively.

RESULTS

Major determinants of each remodeling pattern were high age for electrical (odds ratio = 2.32, 95% confidence interval = 1.68-3.25) and combined remodeling (2.57, 1.88-3.49); female for electrical (3.85, 2.21-6.71) and combined remodeling (4.92, 2.90-8.25); persistent AF for combined remodeling (7.09, 3.75-13.4); and heart failure for volumetric (1.71, 1.51-2.53) and combined remodeling (2.21, 1.30-3.75). Recurrence rate after initial ablation increased in the order of minimal remodeling (20.1%), volumetric (27.4%) or electrical remodeling (36.5%), and combined remodeling (50.0%, p < .0001). A composite endpoint of heart failure, stroke, and death occurred in the order of minimal (3.4%), volumetric (7.5%) or electrical (8.3%), and combined remodeling (15.2%, p < .0001).

CONCLUSION

Volumetric, electrical, and combined remodeling were each associated with a unique patient background, and defined rhythm and other clinical outcomes.

Comparison of voltage maps using OCTARAY catheter and PENTARAY catheter

BACKGROUND

Recently, a new OCTARAY® mapping catheter was commercially launched. The catheter is designed to enable high-density mapping and precise signal recording via 48 small electrodes arranged on eight radiating splines. The purpose of this study was to compare bipolar voltage and low-voltage-area size, and mapping efficacy between the OCTARAY catheter and the PENTARAY® catheter METHODS: Twelve consecutive patients who underwent initial and second ablations for persistent atrial fibrillation within 2 years were considered for enrollment. Voltage mapping was performed twice, first during the initial ablation using the PENTARY catheter and second during the second ablation using the OCTARAY Long 3-3-3-3-3 (L3) catheter.

RESULTS

Mean voltage with the OCTARAY-L3 catheter (1.64 ± 0.57 mV) was 32.3% greater than that with the PENTARAY catheter (1.24 ± 0.46 mV, p < .0001) in total left atrium. Low-voltage-area (<0.50 mV) size with the OCTARAY-L3 catheter was smaller than that with the PENTARAY catheter (6.9 ± 9.7 vs. 11.4 ± 13.0 cm2 , p < .0001). The OCTARAY-L3 catheter demonstrated greater efficacy than the PENTARAY catheter in terms of shorter mapping time (606 ± 99 vs. 782 ± 211 s, p = .008) and more mapping points (3,026 ± 838 vs. 781 ± 342 points, p < .0001).

CONCLUSION

The OCTARAY catheter demonstrated higher voltage recordings, narrower low-voltage areas, and a more efficacious mapping procedure than the PENTARAY catheter.

Tests of Light-Lepton Universality in Angular Asymmetries of B^{0}→D^{*-}ℓν Decays

We present the first comprehensive tests of the universality of the light leptons in the angular distributions of semileptonic B^{0}-meson decays to charged spin-1 charmed mesons. We measure five angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral B is fully reconstructed in ϒ(4S)→BB[over ¯] decays in data corresponding to 189  fb^{-1} integrated luminosity from electron-positron collisions collected with the Belle II detector. We find no significant deviation from the standard model expectations.

Precise Measurement of the D_{s}^{+} Lifetime at Belle II

We measure the lifetime of the D_{s}^{+} meson using a data sample of 207  fb^{-1} collected by the Belle II experiment running at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The lifetime is determined by fitting the decay-time distribution of a sample of 116×10^{3} D_{s}^{+}→ϕπ^{+} decays. Our result is τ_{D_{s}^{+}}=(499.5±1.7±0.9)  fs, where the first uncertainty is statistical and the second is systematic. This result is significantly more precise than previous measurements.

Initial multicenter clinical experience with the first-generation endoscopic guided laser balloon in Japan

BACKGROUND

Isolation of the pulmonary veins (PVs) is the golden standard for atrial fibrillation (AF) ablation. To achieve a permanent PV isolation, the endoscopic guided HeartLight laser balloon system was invented. We analyzed the safety and efficacy of this laser balloon system.

METHODS AND RESULTS

Three hundred four patients from 21 investigational sites inside Japan were enrolled in this study. One thousand sixty-two out of 1175 PVs (90.4%) were isolated using the HeartLight laser balloon. The isolation rate of the left superior, left inferior, right superior, and right inferior PVs was 87.8%, 91.3%, 91.6%, and 92.1%, respectively. The procedure time, defined as the time from the venous access to taking out the balloon, was 155 ± 39 min. The fluoroscopic time was 44 ± 25 min. The mean follow-up period was 309 ± 125 days. The freedom from AF recurrence at 3 months was 89.0% and at 12 months 82.1%. Adverse events occurred in 22 patients (7.2%) including phrenic nerve injury lasting more than 3 months in 1.6% and strokes in 1.0% of the patients.

CONCLUSIONS

This initial experience demonstrated that the laser balloon ablation was feasible for PV isolation in Japanese AF patients.

Search for a τ^{+}τ^{-} Resonance in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} Events with the Belle II Experiment

We report the first search for a nonstandard-model resonance decaying into τ pairs in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} events in the 3.6-10  GeV/c^{2} mass range. We use a 62.8  fb^{-1} sample of e^{+}e^{-} collisions collected at a center-of-mass energy of 10.58 GeV by the Belle II experiment at the SuperKEKB collider. The analysis probes three different models predicting a spin-1 particle coupling only to the heavier lepton families, a Higgs-like spin-0 particle that couples preferentially to charged leptons (leptophilic scalar), and an axionlike particle, respectively. We observe no evidence for a signal and set exclusion limits at 90% confidence level on the product of cross section and branching fraction into τ pairs, ranging from 0.7 to 24 fb, and on the couplings of these processes. We obtain world-leading constraints on the couplings for the leptophilic scalar model for masses above 6.5  GeV/c^{2} and for the axionlike particle model over the entire mass range.

Measurement of CP Violation in B^{0}→K_{S}^{0}π^{0} Decays at Belle II

We report a measurement of the CP-violating parameters C and S in B^{0}→K_{S}^{0}π^{0} decays at Belle II using a sample of 387×10^{6}  BB[over ¯] events recorded in e^{+}e^{-} collisions at a center-of-mass energy corresponding to the ϒ(4S) resonance. These parameters are determined by fitting the proper decay-time distribution of a sample of 415 signal events. We obtain C=-0.04_{-0.15}^{+0.14}±0.05 and S=0.75_{-0.23}^{+0.20}±0.04, where the first uncertainties are statistical and the second are systematic.

Gender Differences in Atrial Fibrosis and Cardiomyopathy Assessed by Left Atrial Low-Voltage Areas During Catheter Ablation of Atrial Fibrillation

Atrial myocardial degeneration predisposes to atrial fibrillation (AF), ischemic stroke, and heart failure. Studies suggest the presence of gender differences in atrial myocardial degeneration. This study aimed to delineate gender differences in the prevalence, predictors, and prognostic impact of left atrial low-voltage areas (LVAs). This observational study included 1,488 consecutive patients who underwent initial ablation for AF. Voltage mapping was performed after pulmonary vein isolation during sinus rhythm. LVAs were defined as regions where bipolar peak-to-peak voltage was <0.50 mV. LVA prevalence was higher in women (38.7%) than in men (16.0%). High age, persistent form of AF, diabetes mellitus, and a large left atrium were shown to be common predictors in both gender categories. Heart failure and history of stroke/thromboembolic events were men-specific predictors of LVA existence. Women experienced more AF recurrence than men (31.1% vs 25.7%, p = 0.027). LVA existence was significantly associated with increased AF recurrence in each gender category, with a respective hazard ratio, 95% confidence interval, and p value of 2.45, 1.87 to 3.22, and <0.0001 in men and 1.82, 1.33 to 2.49, and <0.0001 in women. In conclusion, LVA was more frequent in women than men, and predicted frequent AF recurrence irrespective of gender category.

Long-Term Impact of Additional Ablation After Pulmonary Vein Isolation: Results From EARNEST-PVI Trial

Background An optimal strategy for left atrial ablation in addition to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) has not been determined. Methods and Results We conducted an extended follow-up of the multicenter randomized controlled EARNEST-PVI (Efficacy of Pulmonary Vein Isolation Alone in Patients With Persistent Atrial Fibrillation) trial, which compared 12-month rhythm outcomes in patients with persistent AF between patients randomized to a PVI-alone strategy (n=248) or PVI-plus strategy (n=248; PVI followed by left atrial additional ablation, including linear ablation or ablation targeting areas with complex fractionated electrograms). The present study extended the follow-up period to 3 years after enrollment. Outcomes were compared not only between randomly allocated groups but also between on-treatment groups categorized by actually created ablation lesions. Recurrence rate of AF or atrial tachycardia (AT) was lower in the randomly allocated to PVI-plus group than the PVI-alone group (29.0% versus 37.5%, P=0.036). On-treatment analysis revealed that patients with PVI+linear ablation (n=205) demonstrated a lower AF/AT recurrence rate than those with PVI only (26.3% versus 37.8%, P=0.007). In contrast, patients with PVI+complex fractionated electrograms ablation (n=37) had an AF/AT recurrence rate comparable to that of patients with PVI only (40.5% versus 37.8%, P=0.76). At second ablation in 126 patients with AF/AT recurrence, ATs excluding common atrial flutter were more frequent in patients with PVI+linear ablation than in those with PVI only (32.6% versus 5.7%, P<0.0001). Conclusions Left atrial ablation in addition to PVI was efficacious during 3-year follow-up. Linear ablation was superior to other ablation strategies but may increase iatrogenic ATs. Registration URL: http://www.umin.ac.jp/ctr/index-j.htm; Unique identifier: UMIN000019449.

Test of Light-Lepton Universality in the Rates of Inclusive Semileptonic B-Meson Decays at Belle II

We present the first measurement of the ratio of branching fractions of inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test of electron-muon universality, using data corresponding to 189  fb^{-1} from electron-positron collisions collected with the Belle II detector. In events where the partner B meson is fully reconstructed, we use fits to the lepton momentum spectra above 1.3  GeV/c to obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which is the most precise lepton-universality test of its kind and agrees with the standard-model expectation.

Low atrial natriuretic peptide to brain natriuretic peptide ratio is associated with left atrial remodeling

AIMS

Atrial natriuretic peptide (ANP) deficiency is thought to be one of the causes of heart failure induced by atrial fibrillation (AF). Although ANP deficiency is thought to occur as a result of atrial remodeling, data to explain this mechanism are limited. The purpose of this study was to investigate the association between ANP and left atrial remodeling or prognosis of heart failure in patients with AF ablation.

METHODS

In total, 373 consecutive patients who underwent initial ablation for persistent AF [age, 67 ± 10 years; female, 97 (26%)] were retrospectively enrolled. ANP and brain natriuretic peptide (BNP) were measured before the procedure and the ANP/BNP ratio was calculated. Left atrial volume index, left atrial appendage emptying velocity, and left atrial low-voltage areas (LVAs) were used as left atrial-remodeling parameters. The primary outcome of heart failure was defined as the composite of all-cause death or hospitalization due to worsening heart failure.

RESULTS

The median ANP level was 116 (71-178) pg/ml and the median ANP/BNP ratio was 0.65 (0.46-1.00). The ANP/BNP ratio decreased with increasing left atrial volume index or LVAs and with decreasing left atrial appendage emptying velocity. During the 5-year follow-up, freedom from the primary outcome was significantly lower in patients with ANP/BNP ratio ≤0.65 than in those with ANP/BNP ratio >0.65 (84.6% versus 95.6%, P  < 0.01).

CONCLUSION

Secretion of ANP relative to BNP decreased with progression of left atrial remodeling in patients with AF ablation. Furthermore, prognosis of heart failure was poor in patients with a low ANP/BNP ratio.

First Measurement of the Michel Parameter ξ^{'} in the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} Decay at Belle

We report the first measurement of the Michel parameter ξ^{'} in the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decay with a new method proposed just recently. The measurement is based on the reconstruction of the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} events with subsequent muon decay in flight in the Belle central drift chamber. The analyzed data sample of 988  fb^{-1} collected by the Belle detector corresponds to approximately 912×10^{6} τ^{+}τ^{-} pairs. We measure ξ^{'}=0.22±0.94(stat)±0.42(syst), which is in agreement with the standard model prediction of ξ^{'}=1. Statistical uncertainty dominates in this study, being a limiting factor, while systematic uncertainty is well under control. Our analysis proved the practicability of this promising method and its prospects for further precise measurement in future experiments.

Search for an Invisible Z^{'} in a Final State with Two Muons and Missing Energy at Belle II

The L_{μ}-L_{τ} extension of the standard model predicts the existence of a lepton-flavor-universality-violating Z^{'} boson that couples only to the heavier lepton families. We search for such a Z^{'} through its invisible decay in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'}. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58 GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7  fb^{-1}. We find no excess over the expected standard-model background. We set 90%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×10^{-3} at low Z^{'} masses to 1 at Z^{'} masses of 8  GeV/c^{2}.

First Measurement of the B^{+}→π^{+}π^{0}π^{0} Branching Fraction and CP Asymmetry

We study B^{+}→π^{+}π^{0}π^{0} using 711  fb^{-1} of data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We measure an inclusive branching fraction of (19.0±1.5±1.4)×10^{-6} and an inclusive CP asymmetry of (9.2±6.8±0.7)%, where the first uncertainties are statistical and the second are systematic, and a B^{+}→ρ(770)^{+}π^{0} branching fraction of (11.2±1.1±0.9_{-1.6}^{+0.8})×10^{-6}, where the third uncertainty is due to possible interference with B^{+}→ρ(1450)^{+}π^{0}. We present the first observation of a structure around 1  GeV/c^{2} in the π^{0}π^{0} mass spectrum, with a significance of 6.4σ, and measure a branching fraction to be (6.9±0.9±0.6)×10^{-6}. We also report a measurement of local CP asymmetry in this structure.

Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II

We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8  fb^{-1}, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} and τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ^{-}→e^{-}α)/B(τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ}) in the range (1.1-9.7)×10^{-3} and on B(τ^{-}→μ^{-}α)/B(τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}) in the range (0.7-12.2)×10^{-3} for α masses between 0 and 1.6  GeV/c^{2}. These results provide the most stringent bounds on invisible boson production from τ decays.

First Observation of Λπ^{+} and Λπ^{-} Signals near the K[over ¯]N(I=1) Mass Threshold in Λ_{c}^{+}→Λπ^{+}π^{+}π^{-} Decay

Using the data sample of 980  fb^{-1} collected with the Belle detector operating at the KEKB asymmetric-energy e^{+}e^{-} collider, we present the results of an investigation of the Λπ^{+} and Λπ^{-} invariant mass distributions looking for substructure in the decay Λ_{c}^{+}→Λπ^{+}π^{+}π^{-}. We find a significant signal in each mass distribution. When interpreted as resonances, we find for the Λπ^{+} (Λπ^{-}) combination a mass of 1434.3±0.6(stat)±0.9(syst)  MeV/c^{2} [1438.5±0.9(stat)±2.5(syst)  MeV/c^{2}], an intrinsic width of 11.5±2.8(stat)±5.3(syst)  MeV/c^{2} [33.0±7.5(stat)±23.6(syst)  MeV/c^{2}] with a significance of 7.5σ (6.2σ). As these two signals are very close to the K[over ¯]N threshold, we also investigate the possibility of a K[over ¯]N cusp, and find that we cannot discriminate between these two interpretations due to the limited size of the data sample.

Impact of intravascular ultrasound parameters and platelet reactivity on primary patency after drug-coated balloon angioplasty for femoropopliteal artery disease

Although the superiority of DCBs to uncoated balloon angioplasty for the treatment of femoropopliteal (FP) lesions has been demonstrated, the association of clinical factors, including anatomical features evaluated by intravascular ultrasound (IVUS) and platelet reactivity, with the loss of patency has not been systematically studied. The current prospective, observational study enrolled 160 consecutive patients (male 67.5%, mean age 74.7 ± 9.7 years) with 213 FP lesions treated with DCBs under IVUS evaluation. The platelet reactivity was measured in P2Y12 reaction units for all of the patients at the DCB treatment. The primary end point was primary patency at 12 months, while the secondary end points were freedom from target lesion revascularization (TLR), all-cause death, major target limb amputation and bleeding events at 12 months. Mean lesion length was 11.9 ± 9.4 cm and 34 (16.0%) were chronic total occlusions (CTOs). Thirty-four (16.0%) were severely calcified lesions. Primary patency by Kaplan-Meier estimate was 79.2% at 12 months, while the 12-month freedom from TLR, all-cause death and bleeding events were observed in 89.1%, 93.4% and 97.4%, respectively. There were no major target limb amputations through 12 months. Multivariate analysis showed that subintimal angioplasty for CTO lesions was a sole risk factor for loss of 12-month primary patency, while other IVUS parameters and platelet reactivity were not.

Observation of e^{+}e^{-}→ωχ_{bJ}(1P) and Search for X_{b}→ωϒ(1S) at sqrt[s] near 10.75 GeV

We study the processes e^{+}e^{-}→ωχ_{bJ}(1P) (J=0, 1, or 2) using samples at center-of-mass energies sqrt[s]=10.701, 10.745, and 10.805 GeV, corresponding to 1.6, 9.8, and 4.7  fb^{-1} of integrated luminosity, respectively. These data were collected with the Belle II detector during special operations of the SuperKEKB collider above the ϒ(4S) resonance. We report the first observation of ωχ_{bJ}(1P) signals at sqrt[s]=10.745  GeV. By combining Belle II data with Belle results at sqrt[s]=10.867  GeV, we find energy dependencies of the Born cross sections for e^{+}e^{-}→ωχ_{b1,b2}(1P) to be consistent with the shape of the ϒ(10753) state. These data indicate that the internal structures of the ϒ(10753) and ϒ(10860) states may differ. Including data at sqrt[s]=10.653  GeV, we also search for the bottomonium equivalent of the X(3872) state decaying into ωϒ(1S). No significant signal is observed for masses between 10.45 and 10.65  GeV/c^{2}.

Angioscopic Evaluation of Vascular Response After Fluoropolymer-Based Drug-Eluting Stent Implantation for Femoropopliteal Artery Lesions

BACKGROUND

Although favorable clinical outcomes have been demonstrated for fluoropolymer-based paclitaxel-eluting stents (FP-DES) in the treatment of femoropopliteal lesions, the vascular response after implantation has not been systematically studied through intravascular imaging.Methods and Results: We angioscopically compared FP-DES: 24 in the early phase (mean [±SD] 3±1 months), 26 in the middle phase (12±3 months), and 20 in the late phase (≥18 months) after implantation. The dominant neointimal coverage grade, heterogeneity of neointimal coverage grade, and thrombus adhesion in the stent segment were evaluated. Neointimal coverage was graded as follows: Grade 0, stent struts exposed; Grade 1, struts bulging into the lumen, although covered; Grade 2, struts embedded in the neointima, but visible; Grade 3, struts fully embedded and invisible. Dominant neointimal coverage and heterogeneity grades were significantly higher in the middle and late phases than in the early phase (all P<0.05), but did not differ significantly between the middle and late phases. The incidence of thrombus adhesion was recorded for all stents in each of the 3 different phases.

CONCLUSIONS

The middle and late phases after FP-DES implantation were associated with significantly higher dominant neointimal coverage and heterogeneity grades than the early phase. However, thrombus adhesion was observed in all phases after FP-DES implantation. Arterial healing may not be completed even in the late phase after FP-DES implantation.

Measurement of the Λ_{c}^{+} Lifetime

An absolute measurement of the Λ_{c}^{+} lifetime is reported using Λ_{c}^{+}→pK^{-}π^{+} decays in events reconstructed from data collected by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. The total integrated luminosity of the data sample, which was collected at center-of-mass energies at or near the ϒ(4S) resonance, is 207.2  fb^{-1}. The result, τ(Λ_{c}^{+})=203.20±0.89±0.77  fs, where the first uncertainty is statistical and the second systematic, is the most precise measurement to date and is consistent with previous determinations.

Search for a Dark Photon and an Invisible Dark Higgs Boson in μ^{+}μ^{-} and Missing Energy Final States with the Belle II Experiment

The dark photon A^{'} and the dark Higgs boson h^{'} are hypothetical particles predicted in many dark sector models. We search for the simultaneous production of A^{'} and h^{'} in the dark Higgsstrahlung process e^{+}e^{-}→A^{'}h^{'} with A^{'}→μ^{+}μ^{-} and h^{'} invisible in electron-positron collisions at a center-of-mass energy of 10.58 GeV in data collected by the Belle II experiment in 2019. With an integrated luminosity of 8.34  fb^{-1}, we observe no evidence for signal. We obtain exclusion limits at 90% Bayesian credibility in the range of 1.7-5.0 fb on the cross section and in the range of 1.7×10^{-8}-200×10^{-8} on the effective coupling ϵ^{2}×α_{D} for the A^{'} mass in the range of 4.0  GeV/c^{2}<M_{A^{'}}<9.7  GeV/c^{2} and for the h^{'} mass M_{h^{'}}<M_{A^{'}}, where ϵ is the mixing strength between the standard model and the dark photon and α_{D} is the coupling of the dark photon to the dark Higgs boson. Our limits are the first in this mass range.

Cryoballoon ablation and cardioversion using intracardiac defibrillation catheter for atrial fibrillation in a patient with deep brain stimulation

Deep brain stimulation (DBS) is a well-established therapy for drug-refractory Parkinson's disease. As 100-200 Hz signals from DBS are transmitted from the generator implanted subcutaneously in the anterior chest wall, there is a risk of central nervous system damage by radiofrequency energy or cardioversion. A 76-year-old female with a DBS was admitted for catheter ablation because of palpitation and syncope by paroxysmal atrial fibrillation. There may have been a risk of central nervous system damage and DBS electrode malfunction by radiofrequency energy and defibrillation shocks. In addition, cardioversion by an external defibrillator had the possibility to cause brain injury in patients with DBS. Therefore, pulmonary vein isolation by cryoballoon and cardioversion using an intracardiac defibrillation catheter were performed. Despite continued application of DBS during the procedure, no complications occurred. This is the first case report of cryoballoon ablation accompanied with intracardiac defibrillation under continued DBS. Cryoballoon ablation may be an alternative atrial fibrillation ablation method to radiofrequency catheter ablation for patients with DBS. Additionally, intracardiac defibrillation may reduce the risk of central nervous system damage and DBS malfunction.

Learning objective

Deep brain stimulation (DBS) is a well-established therapy for Parkinson's disease. In patients with DBS, there is a risk of central nervous system damage by radiofrequency energy or cardioversion by an external defibrillator. Cryoballoon ablation may be an alternative atrial fibrillation ablation method to radiofrequency catheter ablation for patients with continued DBS. In addition, intracardiac defibrillation may reduce the risk of central nervous system damage and DBS malfunction.

Evidence of a New Excited Charmed Baryon Decaying to Σ_{c}(2455)^{0,++}π^{±}

We present the study of B[over ¯]^{0}→Σ_{c}(2455)^{0,++}π^{±}p[over ¯] decays based on 772×10^{6}  BB[over ¯] events collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The Σ_{c}(2455)^{0,++} candidates are reconstructed via their decay to Λ_{c}^{+}π^{∓} and Λ_{c}^{+} decays to pK^{-}π^{+}, pK_{S}^{0}, and Λπ^{+} final states. The corresponding branching fractions are measured to be B(B[over ¯]^{0}→Σ_{c}(2455)^{0}π^{+}p[over ¯])=(1.09±0.06±0.07)×10^{-4} and B(B[over ¯]^{0}→Σ_{c}(2455)^{++}π^{-}p[over ¯])=(1.84±0.11±0.12)×10^{-4}, which are consistent with the world average values with improved precision. A new structure is found in the M_{Σ_{c}(2455)^{0,++}π^{±}} spectrum with a significance of 4.2σ including systematic uncertainty. The structure is possibly an excited Λ_{c}^{+} and is tentatively named Λ_{c}(2910)^{+}. Its mass and width are measured to be (2913.8±5.6±3.8)  MeV/c^{2} and (51.8±20.0±18.8)  MeV, respectively. The products of branching fractions for the Λ_{c}(2910)^{+} are measured to be B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{0}π^{+})=(9.5±3.6±1.6)×10^{-6} and B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{++}π^{-})=(1.24±0.35±0.10)×10^{-5}. Here, the first and second uncertainties are statistical and systematic, respectively.

Clinical trajectories and outcomes of patients with heart failure with preserved ejection fraction with normal or indeterminate diastolic function

BACKGROUND

We recently reported that nearly half of patients with heart failure with preserved ejection fraction (HFpEF) did not show echocardiographic diastolic dysfunction (DD), but had normal diastolic function (ND) or indeterminate diastolic function (ID). However, the clinical course and outcomes of patients with HFpEF with ND or ID (ND/ID) remain unknown.

METHODS

From the PURSUIT-HFpEF registry, we extracted 289 patients with HFpEF with ND/ID at discharge who had echocardiographic data at 1-year follow-up. Patients were classified according to the status of progression from ND/ID to DD at 1 year. Primary endpoint was a composite of all-cause death or HF rehospitalization.

RESULTS

Median age was 81 years, and 138 (47.8%) patients were female. At 1 year, 107 (37%) patients had progressed to DD. The composite endpoint occurred in 90 (31.1%) patients. Compared to patients without progression to DD, those with progression had a significantly higher cumulative rate of the composite endpoint (P < 0.001) and HF rehospitalization (P < 0.001) after discharge and at the 1-year landmark (P = 0.030 and P = 0.001, respectively). Progression to DD was independently associated with the composite endpoint (hazard ratio (HR): 2.014, 95%CI 1.239-3.273, P = 0.005) and HF rehospitalization (HR: 2.362, 95%CI 1.402-3.978) after discharge. Age (odds ratio (OR): 1.043, 95%CI 1.004-1.083, P = 0.031), body mass index (BMI) (OR: 1.110, 95%CI 1.031-1.195, P = 0.006), and albumin (OR: 0.452, 95%CI 0.211-0.969, P = 0.041) were independently associated with progression from ND/ID to DD.

CONCLUSIONS

More than one-third of HFpEF patients with ND/ID progressed to DD at 1 year and had poor outcomes. Age, BMI and albumin were independently associated with this progression.

UMIN-CTR ID

UMIN000021831.

Extensive ablation strategy for persistent atrial fibrillation impairs left atrial function but reduces recurrence rate

Background

In catheter ablation for persistent atrial fibrillation (AF), extensive ablation strategy, such as linear ablation and/or complex fractionated atrial electrogram (CFAE) ablation in addition to pulmonary vein isolation (PVI-plus), might impair left atrial function more severely than PVI-alone strategy.

Purpose

The aim of this study is to investigate the impact of extensive ablation strategy on LA function and assess the relationship between post-ablation LA function and recurrence.

Methods

This study is a post-hoc subanalysis of the EARNEST-PVI randomized controlled trial, which investigated the efficacy of the PVI-alone strategy in comparison with PVI-plus strategy for persistent AF. From the 497 participants of EARNEST-PVI trial, we enrolled 191 patients with full datasets of pre- and post-ablation cardiac computed tomography (CT) at our Hospital. Patients were divided into PVI-alone and PVI-plus groups. Within one month before and 3 months after ablation, LA volume index (LAVI) and LA emptying fraction (LAEF) were calculated by using the Comprehensive Cardiac Analysis software on the Extended Brilliance Workspace. We assessed i) post-ablation LA function, ii) AF/atrial tachycardia (AT) -free rate after single and final session, and iii) relationship between post-ablation LAEF and ablation success in each group.

Results

The indices of baseline LA remodeling were not different between PVI-alone (N=96) and PVI-plus groups (N=95) [LAVI: 71.4 (57.8, 82.0) vs. 68.7 (61.0, 78.1), P=0.92, LAEF: 13.7 (10.0, 17.4) vs. 13.0 (10.0, 16.9), PVI-alone vs. PVI-plus, P=0.78]. In overall patients, post-ablation LAEF did not differ among them [34.4 (26.1, 40.7) vs. 31.6 (26.0, 37.4), P=0.13]. In the analysis of patients showing sinus rhythm during the CT study, LAEF was significantly higher in PVI-alone (N=87) than in PVI-plus group (N=93) [35.7 (29.0, 41.0) vs. 31.7 (26.1, 37.5), P=0.011] (Figure 1A). AF/AT-free survival rate during median follow-up of 44 months was not different after first session (63.5% vs. 68.4%, P=0.33), while PVI-plus had a tendency towards higher success rate after final session (72.9% vs. 84.2%, P=0.053) (Figure 2). In receiver operating characteristics analysis for recurrence after first session, post-ablation decreased LAEF had significantly related to recurrence after PVI-alone (AUC: 0.733, P&lt;0.0001), but not after PVI-plus (AUC: 0.567, P=0.31) (Figure 1B, C).

Conclusion

Compared with PVI-alone strategy, PVI-plus strategy damaged LA function more severely, but tended to be related to higher success rate. Post-ablation LA function was related to recurrence in PVI-alone, but not in PVI-plus. Extensive ablation might have additional anti-arrhythmic effect regardless of iatrogenic myocardial damage. Myocardial injury by extensive ablation may less attribute to recurrence than intrinsic damage of LA.

Funding Acknowledgement

Type of funding sources: None.

Premature atrial contraction on Holter electrocardiogram predicts the recurrence of atrial fibrillation after catheter ablation

Introduction

It is important to detect the recurrence of atrial fibrillation (AF) after catheter ablation (CA) early, but the method of detection has not been established. The purpose of this study is to determine whether 24-h Holter electrocardiogram (ECG) can predict the recurrence of AF after CA.

Methods

We studied 336 patients of 497 patients enrolled in EARNEST-PVI trial to investigate whether the total number of premature atrial contraction (PAC) and the maximum number of PAC run by 24-h Holter ECG at 6 months after CA predicted AF recurrence after 6 months. We excluded 86 patients with recurrence by 6 months after CA and 75 patients without Holter ECG at 6 months after CA.

Results

Median age was 66 years, male were 77% and median follow-up period was 1138 days. Receiver operating characteristic curve analysis identified the total number of PAC ≥270 beats and the maximum number of PAC run ≥8 beats as the optimal cutoff for prediction of AF recurrence. Kaplan-Meier analysis showed patients with the total number of PAC ≥270 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 34% vs. 17%, Log-rank P=0.001) and patients with the maximum number of PAC run ≥8 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 33% vs. 20%, Log-rank P=0.006). Multivariate analysis revealed that the total number of PAC ≥270 beats and the maximum number of PAC run were significantly associated with AF recurrence (hazard ratio [95% confidence interval] 1.83 [1.16–2.91], P=0.01 and 1.01 [1.01–1.02], P=0.001, respectively)

Conclusion

The total number of PAC and the maximum number of PAC run on the Holter ECG may be useful in predicting AF recurrence after CA.

Funding Acknowledgement

Type of funding sources: None.

Heart Rate Decrease After Atrial Fibrillation Catheter Ablation Predicts Decompensated Heart Failure After the Procedure

Background: Decompensated heart failure (DHF) can complicate catheter ablation for atrial fibrillation (AF). We investigated the association between heart rate and DHF in AF patients undergoing catheter ablation.

Methods and Results: In all, 1,004 consecutive patients who underwent initial ablation for AF (mean [±SD] age 68±10 years; 34% female; persistent AF n=513 [51%]) were enrolled in the study. Heart rate was assessed before and after ablation. DHF was defined as heart failure requiring medical therapy within 2 days after the procedure. The incidence of DHF was 2% (22 of 1,004 patients). Patients with DHF had a higher prevalence of a history of symptomatic heart failure (11/22 [50%] vs. 160/982 [16%]; P<0.0001) and a greater degree of heart rate decrease after the procedure (−21±29 vs. 2±21 beats/min; P=0.001) than those without DHF. On multivariate analysis, heart rate decrease was a significant independent predictor of DHF (hazard ratio 0.8; 95% confidence interval 0.7–0.9; P=0.004; 10 beats/min-increment).

Conclusions: In patients undergoing AF ablation, a decrease in heart rate after the procedure was an independent predictor of DHF.

DR-FLASH Score Is Useful for Identifying Patients With Persistent Atrial Fibrillation Who Require Extensive Catheter Ablation Procedures

Background

Modification of arrhythmogenic substrates with extensive ablation comprising linear and/or complex fractional atrial electrogram ablation in addition to pulmonary vein isolation (PVI‐plus) can theoretically reduce the recurrence of atrial fibrillation. The DR‐FLASH score (score based on diabetes mellitus, renal dysfunction, persistent form of atrial fibrillation, left atrialdiameter >45 mm, age >65 years, female sex, and hypertension) is reportedly useful for identifying patients with arrhythmogenic substrates. We hypothesized that, in patients with persistent atrial fibrillation, the DR‐FLASH score can be used to classify patients into those who require PVI‐plus and those for whom a PVI‐only strategy is sufficient.

Methods and Results

This study is a post hoc subanalysis of the a multicenter, randomized controlled, noninferiority trial investigating efficacy and safety of pulmonary vein isolation alone for recurrence prevention compared with extensive ablation in patients with persistent atrial fibrillation (EARNEST‐PVI trial). This analysis focuses on the relationship between DR‐FLASH score and the efficacy of different ablation strategies. We divided the population into 2 groups based on a DR‐FLASH score of 3 points. A total of 469 patients were analyzed. Among those with a DR‐FLASH score >3 (N=279), the event rate of atrial arrhythmia recurrence was significantly lower in the PVI‐plus arm than in the PVI‐only arm (hazard ratio [HR], 0.45 [95% CI, 0.28–0.72]; P<0.001). In contrast, among patients with a DR‐FLASH score ≤3 (N=217), no differences were observed in the event rate of atrial arrhythmia recurrence between the PVI‐only arm and the PVI‐plus arm (HR, 1.08 [95% CI, 0.61–1.89]; P=0.795). There was significant interaction between patients with a DR‐FLASH score >3 and DR‐FLASH score ≤3 (P value for interaction=0.020).

Conclusions

The DR‐FLASH score is a useful tool for deciding the catheter ablation strategy for patients with persistent atrial fibrillation.

Registration

URL: https://clinicaltrials.gov; Unique identifier: NCT03514693.

Impact of left atrial low-voltage areas during initial ablation procedures on very late recurrence of atrial fibrillation

BACKGROUND

Very late recurrence of atrial fibrillation (VLRAF) occurring >1 year after catheter ablation may influence long-term follow-up strategies, including oral anticoagulant therapy. However, little is known about the predictors of this condition. Given that the prevalence of left atrial low-voltage areas (LVAs) is strongly associated with the recurrence of atrial tachyarrhythmias following catheter ablation, we hypothesized that VLRAF might occur more frequently in patients with LVAs at the time of initial ablation. The purpose of this study was to investigate the impact of LVAs on VLRAF.

METHODS

This study included 1001 consecutive patients undergoing initial ablation procedures for AF. LVAs were defined as regions with bipolar peak-to-peak voltages of <0.50 mV on the voltage map obtained during sinus rhythm after pulmonary vein isolation. During a 1-year follow-up period, 248 patients had a late recurrence of AF (LRAF), defined as recurrence within 3 to 12 months after ablation. The occurrence of VLRAF was examined in 711 patients without LRAF who were followed for more than 1 year.

RESULTS

A total of 711 patients who did not develop AF recurrence within 1 year and for whom clinical data were available after 1 year were analyzed. During a median follow-up of 25 (19, 37) months, VLRAF more than one year after the initial ablation was detected in 123 patients. On multivariate analysis, independent predictors of VLRAF were the existence of LVAs, female, left atrial diameter and early recurrence of AF. A Kaplan-Meier analysis showed that the AF-free survival rate was significantly lower in patients with LVAs than in those without LVAs within 1 year and on more than 1 year follow-up. (P<0.001) An additional Kaplan-Meier analysis of the incidence of VLRAF in propensity score-matched patients with and without LVAs showed that VLRAF occurred significantly more frequently in patients with LVAs. (P=0.003) CONCLUSIONS: LVAs during the initial AF ablation procedures have an impact on VLRAF occurrence. This article is protected by copyright. All rights reserved.

Predictive impact of the Global Limb Anatomic Staging System (GLASS) on perioperative outcomes in patients with chronic limb-threatening ischaemia with isolated below-the-knee lesions

Although the global vascular guidelines recently proposed the Global Limb Anatomic Staging System (GLASS) as an anatomical classification for chronic limb-threatening ischaemia (CLTI), prediction of perioperative outcomes using the GLASS classification in patients with CLTI due to isolated below-the-knee (BTK) lesions has not been well studied.This retrospective study included 585 patients with CLTI due to isolated BTK lesions who underwent endovascular therapy (EVT). The severity of arterial lesions was graded using the GLASS infrapopliteal (IP) and inframalleolar (IM) classifications and defined as follows: non-severe IP, 0-3; severe IP, 4; non-severe IM, P0-1; and severe IM, P2. The outcome measures were technical failure, defined as recanalisation failure of the target artery path, and perioperative failure, defined as a composite of all-cause death, major amputation, or repeat revascularisation within 30 days.Technical and perioperative failures occurred in 9.4% (n = 55) and 9.9% (n = 58) patients, respectively. Compared to patients with non-severe IP and IM, those with both severe IP and IM were significantly associated with technical and perioperative failures (odds ratio [OR]: 13.87 [95% confidence interval (CI) 4.69-41.02, P < 0.001] and OR: 2.18 [95% CI 1.08-4.38, P = 0.041], respectively).The GLASS classification may have predictive value for technical and perioperative failure in patients with CLTI due to isolated BTK lesions after EVT.

Measurement of Two-Particle Correlations of Hadrons in e^{+}e^{-} Collisions at Belle

The measurement of two-particle angular correlation functions in high-multiplicity e^{+}e^{-} collisions at sqrt[s]=10.52  GeV is reported. In this study, the 89.5  fb^{-1} of hadronic e^{+}e^{-} annihilation data collected by the Belle detector at KEKB are used. Two-particle angular correlation functions are measured in the full relative azimuthal angle (Δϕ) and three units of pseudorapidity (Δη), defined by either the electron beam axis or the event-shape thrust axis, and are studied as a function of charged-particle multiplicity. The measurement in the thrust axis analysis, with mostly outgoing quark pairs determining the reference axis, is sensitive to the region of additional soft gluon emissions. No significant anisotropic collective behavior is observed with either coordinate analyses. Near-side jet correlations appear to be absent in the thrust axis analysis. The measurements are compared to predictions from various event generators and are expected to provide new constraints to the phenomenological models in the low-energy regime.

Association between prognosis and the use of angiotensin‐converting enzyme inhibitors and/or angiotensin II receptor blockers in frail patients with heart failure with preserved ejection fraction

Aims

The effectiveness of angiotensin‐converting enzyme inhibitors (ACE‐I) and angiotensin II receptor blockers (ARB) has not been demonstrated in patients with heart failure with preserved ejection fraction (HFpEF). We recently reported significant interaction between the use of ACE‐I and/or ARB (ACE‐I/ARB) and frailty on prognosis in patients with HFpEF. In the present study, we examined the association between ACE‐I/ARB and prognosis in patients with HFpEF stratified by the presence or absence of frailty.

Methods and results

We examined the association between the use of ACE‐I/ARB and prognosis according to the presence [Clinical Frailty Scale (CFS) ≥ 5] or absence (CFS ≤ 4) of frailty in patients with HFpEF in a post hoc analysis of registry data. Primary endpoint was the composite of all‐cause mortality and heart failure admission. Secondary endpoints were all‐cause mortality and heart failure admission. Of 1059 patients, median age was 83 years and 45% were male. Kaplan–Meier analysis showed that the risk of composite endpoint (log‐rank P = 0.001) and all‐cause death (log‐rank P = 0.005) in patients with ACE‐I/ARB was lower in those with CFS ≥ 5, but similar between patients with and without ACE‐I/ARB in patients with CFS ≤ 4 (composite endpoint: log‐rank P = 0.830; all‐cause death: log‐rank P = 0.192). In a multivariable Cox proportional hazards model, use of ACE‐I/ARB was significantly associated with lower risk of the composite endpoint [hazard ratio (HR) = 0.52, 95% confidence interval (CI) = 0.33–0.83, P = 0.005] and heart failure admission (HR = 0.45, 95% CI = 0.25–0.83, P = 0.010) in patients with CFS ≥ 5, but not in patients with CFS ≤ 4 (composite endpoint: HR = 1.41, 95% CI = 0.99–2.02, P = 0.059; heart failure admission: HR = 1.43, 95% CI = 0.94–2.18, P = 0.091). The association between ACE‐I or ARB and prognosis did not significantly differ by CFS (CFS ≤ 4: log‐rank P = 0.562; CFS ≥ 5: log‐rank P = 0.100, for with ACE‐I vs. ARB, respectively). Adjusted HRs for CFS 1–4 were higher than 1.0 but were <1.0 at CFS 5.

Conclusions

In patients with HFpEF, use of ACE‐I/ARB was associated with better prognosis in patients with frailty as assessed with the CFS, but not in those without frailty.

Influence of catheter ablation for atrial fibrillation on atrial and ventricular functional mitral regurgitation

Aims

The purpose of this study was to compare the impact of catheter ablation on cardiac structural reverse remodelling and atrial (AFMR) and ventricular (VFMR) functional mitral regurgitation (MR), and the long‐term prognosis of patients with AFMR and VFMR.

Methods and results

The retrospective study included persistent AF patients who had AFMR (n = 136, left atrial (LA) volume index >30 mL/m² and left ventricular (LV) ejection fraction ≥40%) or VFMR (n = 31, LV ejection fraction <40% or LV regional asynergy) and had undergone the initial AF ablation from April 2015 to December 2019. Baseline and 6 month follow‐up echocardiography were performed to assess MR, LA, and LV sizes. MR improvement after ablation was comparable in the AFMR (64%) and VFMR groups (52%, P = 0.20). Patients with AFMR improvement showed a greater decrease in left atrial volume after ablation than those without (amount of change: −11.4 ± 15.1 vs. −2.3 ± 21.1 mL/m², P = 0.01). Patients with VFMR improvement showed a greater increase in LV ejection fraction than those without (amount of change: 28.5 ± 13.6% vs. 9.0 ± 14.8%, P = 0.001). The composite endpoint of all‐cause death and heart failure hospitalization during the 2 year follow‐up period was more frequently observed in the VFMR than in the AFMR group (22.6% vs. 3.7%, P < 0.0001). Patients with MR improvement after catheter ablation less frequently demonstrated the composite endpoint than those without (1.9% vs. 15.6%, P < 0.0001).

Conclusions

Atrial functional mitral regurgitation and VFMR improvement after ablation were associated with atrial and ventricular reverse remodelling, respectively. It is possible that long‐term prognosis is better in patients with AFMR than with VFMR, and in those with MR improvement than in those without.

Clinical Impact of the Size of Drug-Coated Balloon Therapy on Restenosis Rate in Femoropopliteal Lesions

Purpose:

Although the size of drug-coated balloons (DCBs) is determined according to the vessel diameter during femoropopliteal (FP)-endovascular therapy (EVT), the measurements of the vessel diameter vary among modalities and its definitions. The aim of this study was to reveal whether the DCB size fitting (1) angiographically-measured lumen diameter (Angio-lumen size), (2) intravascular ultrasound (IVUS)-measured lumen diameter (IVUS-lumen size), or (3) IVUS-measured external elastic membrane (EEM) diameter (IVUS-EEM size) would be beneficial in restenosis occurrence.

Materials and Methods:

This retrospective, single-center study included 231 de novo FP lesions in 165 patients with peripheral artery disease treated with IN.PACT Admiral DCB under IVUS evaluation. The reference vessel diameter was evaluated as the lumen or EEM diameter at the healthy site distal to the lesion. We retrospectively determined whether the DCB size was close to (ie, equal to or different by <0.5 mm from) Angio-lumen size, IVUS-lumen size, and IVUS-EEM size. The association of the size of DCB with restenosis risk was investigated.

Results:

The mean lesion length was 13 ± 9 cm and the prevalence of chronic total occlusion was 18%. During a mean follow-up period of 17 ± 9 months, restenosis occurred in 26% of lesions. Lesions treated with a DCB of IVUS-EEM size had a lower 2 year restenosis rate than those treated with a DCB over/under IVUS-EEM size (19.7 ± 5.7% vs 34.5 ± 4.7%, p=0.02 by the log-rank test), while the restenosis rate was not significantly different between DCBs of Angio-lumen size or IVUS-lumen size and those over/under the size (both p>0.05). The multivariate Cox regression analysis revealed that DCBs of IVUS-EEM size were independently associated with a reduced risk of restenosis (adjusted hazard ratio 0.50; 95% confidence interval 0.27–0.95; p=0.03).

Conclusion:

The DCBs of IVUS-EEM size, but not of Angio-lumen size or IVUS-lumen size, were associated with a reduced risk of restenosis after FP-EVT. Determining the DCB size according to IVUS-evaluated EEM diameter would be potentially beneficial in restenosis occurrence.

Relation of left atrial overload indices with prognostic endpoints in heart failure and preserved ejection fraction

Aims

Considerable variation in the relationships between the indices of left atrial (LA) volume and pressure could possibly affect the selection of medications or efforts to improve the prognoses of patients with heart failure and preserved ejection fraction (HFpEF). We aimed to clarify the association between the prognostic endpoint and LA overload indices in elderly patients with HFpEF.

Methods and results

We analysed 898 patients with HFpEF hospitalized for acute decompensated heart failure (men/women: 406/492). Blood tests and transthoracic echocardiography were performed before discharge. The primary endpoint was re‐admission for heart failure or all‐cause mortality. Stroke volume (SV)/left atrial volume (LAV), an index for LA volume overload, was a significant prognostic factor of re‐admission for heart failure in the multivariable Cox hazard analysis adjusted for comorbidities [hazard ratio (HR) 0.616, 95% confidence interval (CI) 0.430–0.882, P = 0.008]. Additionally, the ratio of diastolic elastance (Ed) to arterial elastance (Ea), an index for LA pressure overload, was also significant (HR 1.444, 95% CI 1.014–2.058, P = 0.041). Furthermore, Ed/Ea, but not SV/LAV, was a significant prognostic factor of all‐cause mortality (HR 1.594, 95% CI 1.102–2.306, P = 0.013).

Conclusions

The index of LA overload for prognosis may differ according to the different endpoints in elderly patients with HFpEF.

Search for a Light Higgs Boson in Single-Photon Decays of ϒ(1S) Using ϒ(2S)→π^{+}π^{-}ϒ(1S) Tagging Method

We search for a light Higgs boson (A^{0}) decaying into a τ^{+}τ^{-} or μ^{+}μ^{-} pair in the radiative decays of ϒ(1S). The production of ϒ(1S) mesons is tagged by ϒ(2S)→π^{+}π^{-}ϒ(1S) transitions, using 158×10^{6} ϒ(2S) events accumulated with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant A^{0} signals in the mass range from the τ^{+}τ^{-} or μ^{+}μ^{-} threshold to 9.2  GeV/c^{2} are observed. We set the upper limits at 90% credibility level (C.L.) on the product branching fractions for ϒ(1S)→γA^{0} and A^{0}→τ^{+}τ^{-} varying from 3.8×10^{-6} to 1.5×10^{-4}. Our results represent an approximately twofold improvement on the current world best upper limits for the ϒ(1S)→γA^{0}(→τ^{+}τ^{-}) production. For A^{0}→μ^{+}μ^{-}, the upper limits on the product branching fractions for ϒ(1S)→γA^{0} and A^{0}→μ^{+}μ^{-} are at the same level as the world average limits, and vary from 3.1×10^{-7} to 1.6×10^{-5}. The upper limits at 90% credibility level on the Yukawa coupling f_{ϒ(1S)} and mixing angle sinθ_{A^{0}} are also given.