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Purpose: Ablation index (AI)-guided ablation improves the incidence of arrhythmia recurrence as compared to conventional contact force (CF)-guided ablation. The aim of this study was to elucidate the differences in the biomarkers associated with myocardial injury and inflammation between conventional CF-guided and AI-guided ablation., Methods: Atrial fibrillation (AF) patients who underwent pulmonary vein isolation (PVI) from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry were enrolled. We divided the patients into two groups: conventional CF-guided PVI (CF group) and AI-guided PVI (AI group). The differences in biomarkers associated with myocardial injury and inflammation, and long-term durability of PVI between the two groups were evaluated., Results: This study population included a total of 794 patients (CF-guided, 241 patients; AI-guided, 553 patients). Total application time was significantly shorter, and total application number was significantly smaller in AI than CF group. High-sensitive troponin I (hs-TnI) post-ablation was significantly higher in AI than CF group (p < 0.001), even after taking the total application number and total application time into consideration. No significant differences in inflammatory markers changes from pre- to post-ablation were observed between the two groups. AI-guided ablation was significantly associated with the hs-TnI post-ablation by multiple regression analysis. The PV reconnection ratio was significantly smaller in AI than CF group (p = 0.037)., Conclusions: AI-guided ablation had the ability to create larger lesions than CF-guided ablation despite no increase in inflammation and achieved the better PVI durability than that of CF-guided., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: An ablation index (AI)-guided pulmonary vein isolation (PVI) or 2nd generation cryoballoon (CB)-PVI has been shown to reduce the atrial fibrillation (AF) burden by 99% despite the absence of ablation of non-pulmonary vein (PV) triggers in patients with paroxysmal AF. The purpose of this study was to investigate the effects of PVI alone strategy using 2nd generation CB compared with AI-guided PVI with an additional induction test and subsequent AF trigger ablation., Methods and Results: We investigated 223 patients with symptomatic paroxysmal AF who underwent an initial PVI between August 2018 and August 2020. The study patients were divided into 2 groups: CB-PVI without an induction test (CB-PVI alone group, n = 82) and AI-guided PVI with an induction test and subsequent additional ablation of non-PV triggers (AI-PVI plus group, n = 141). In the AI-PVI plus group, a total of 62 non-PV triggers were induced in 38 patients, and non-PV triggers in 22 patients were completely ablated. The procedure time and left atrium dwell time were significantly shorter in the CB-PVI alone group than AI-PVI plus group. There were no significant differences in the incidence of procedural complications between the 2 groups (P = 0.650). The AF free survival rate in the CB-PVI alone group and AI-PVI plus group was 80% vs. 80% at 24 months (P = 0.969)., Conclusions: An PVI alone strategy using advanced generation CB did not differ in the clinical outcomes compared with an AI-guided PVI strategy with an induction test and subsequent ablation of non-PV triggers in the patients with paroxysmal AF., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Although much has been discussed about the early recurrence of atrial fibrillation (ERAF) after cryoballoon ablation (CBA), the clinical impact of very early recurrence of atrial fibrillation (VERAF) after CBA remains unclear. This study aimed to investigate the impact of VERAF after CBA., Methods: We enrolled 236 consecutive patients who underwent an initial CBA for paroxysmal atrial fibrillation between February 2017 and December 2020 in our hospital. These patients were categorized into three groups: VERAF group who experienced an initial recurrence of atrial tachyarrhythmia within 48 h after CBA, late-ERAF (LERAF) group who experienced an initial recurrence of atrial tachyarrhythmia between 48 h and 3 months after CBA, and non-ERAF (NERAF) group who did not experience a recurrence of atrial tachyarrhythmia within 3 months after CBA. We investigated the late recurrence of AF (LRAF, defined as recurrence of atrial tachyarrhythmia more than 3 months after CBA), and the incidence of non-pulmonary vein (PV) triggers in the patients who experienced a repeat ablation procedure due to LRAF., Results: VERAF group had a higher incidence of freedom from LRAF than LERAF group (p = 0.032) and a lower incidence of freedom from LRAF than NERAF group (p = 0.002). Moreover, VERAF group had the highest incidence of non-PV triggers at repeat ablation procedure among the three groups (p = 0.003)., Conclusions: While ERAF was a predictor of LRAF, VERAF was less related to LRAF among the patients with ERAF after CBA. Furthermore, VERAF might be associated with non-PV triggers., (© 2022 Wiley Periodicals LLC.)

At present, it remains unclear whether the effect on cryoinjury can be strongly exerted by contact of the balloon with the pulmonary vein (PV) ostium. The present study included 204 paroxysmal atrial fibrillation (PAF) patients who underwent an initial pulmonary vein isolation (PVI) using a cryoballoon from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. The total balloon contact angle was measured from the equator line (sum of the angles of the upper side and bottom side in all PVs) under fluoroscopic imaging. The patients were stratified into three tertile groups according to the total balloon contact angle. We evaluated the relationship between the total balloon contact angle and clinical outcomes, including the value of acute myocardial injury marker (high-sensitive cardiac troponin I [hs-TnI]), arrhythmia recurrence, and PV reconnections in the repeated ablation. The total balloon contact angle was significantly associated with the hs-TnI value among the tertile groups (p < 0.001) and a multiple regression analysis showed that the total balloon contact angle significantly correlated with the hs-TnI value (standardized beta-coefficient = 0.572, p < 0.001). The balloon contact angle in PVs with PV reconnections was significantly lower than in those without (p = 0.044), while no significant differences in the recurrence of atrial fibrillation among the tertile groups were observed in the enrolled patients. The total balloon contact angle was significantly associated with the acute myocardial injury marker, hs-TnI. The total balloon contact angle was significantly associated with PV reconnections after cryoballoon ablation in patients who underwent a repeat ablation., (© 2022. Springer Japan KK, part of Springer Nature.)

Purpose: Early recurrence of atrial tachyarrhythmias (ERAT) cause various symptoms and predict worse outcomes after pulmonary vein isolation (PVI). This study aimed to clarify whether ablation index (AI)-guided PVI, which is a novel technology of radiofrequency ablation, could reduce ERAT as compared to conventional contact force (CF)-guided PVI., Methods: Consecutive atrial fibrillation (AF) patients who underwent initial PVI from September 2014 to August 2019 were enrolled. We divided the patients into two groups: patients who underwent AI-guided PVI (AI group) and those who underwent CF-guided PVI (CF group). Using propensity score matching (PSM), we adjusted for the patient backgrounds. We compared the incidence of ERAT and late reconnection rate of isolated pulmonary veins (PVs) during second session between the two groups. ERAT was defined as any atrial tachyarrhythmias ≥ 30 s during a 90-day blanking period., Results: A total of 697 AF patients (paroxysmal 51%) were enrolled. After the PSM, both groups included 229 patients. The incidence of ERAT was significantly lower in the AI group than that in the CF group (21.5% vs. 36.1%, P < 0.001). Total 118 patients (25.7%) experienced late recurrence of atrial tachyarrhythmias (LRAT) after blanking period. LRAT free survival rate was significantly higher in patients without ERAT than those with ERAT (88.1% vs. 42.0%, P < 0.001). The rate of PV reconnection was lower in the AI group than that in the CF group (45.8% vs. 71.4%, P = 0.028). Multivariate analysis demonstrated that AI-guided PVI was independently correlated with ERAT (OR = 0.415, 95%CI = 0.269-0.639, P < 0.001)., Conclusions: AI-guided PVI can reduce ERAT as compared to conventional CF-guided PVI., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Local impedance (LI) drop during radiofrequency (RF) application is monitored to assess the lesion formation. Recently, a novel ablation catheter has been introduced to clinical setting, which is capable of monitoring LI and catheter contact parameters including contact force (CF) and contact angle (CA). This study aimed to clarify the correlation between LI drop and catheter contact parameters., Methods and Results: This prospective study included 15 paroxysmal atrial fibrillation (AF) patients who underwent initial pulmonary vein isolation (PVI). First-pass encircling point-by-point PV ablation was performed by using a 4.5-mm irrigated ablation catheter, with monitoring LI, CF, and CA. RF energy was applied for 30 s at each site with 30 W. Stable ablation points were analyzed to examine the correlation between LI drop and catheter contact parameters. Among 903 ablation points, 499 stable ablation points (55.2%) were analyzed. CA showed good correlation with LI drop (ρ = 0.418, p < .001). Maximum CF, minimum CF, average CF, and initial CF all showed weak correlation with LI drop (ρ = 0.201, p < .001; ρ = 0.224, p < .001; ρ = 0.258, p < .001; and ρ = 0.212, p < .001, respectively). Multivariate analysis demonstrated that CA was an independent factor of LI drop among the catheter contact parameters (β = 0.139, 95% CI = 0.111-0.167, p < .001). The LI drop in the blocked segments was significantly higher than that in the electrical conduction gap segments (27.3 ± 9.8 vs. 19.6 ± 6.4 Ω, p < .001) CONCLUSION: In clinical PVI use, both CF and CA were correlated with LI drop. More parallel CA could induce higher LI drop, which may lead to effective lesion formation., (© 2022 Wiley Periodicals LLC.)

Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) causes myocardial injury and induces high-sensitive cardiac troponin I (hs-TnI) release into the systemic circulation. Several factors are considered to be associated with myocardial injury after ablation, but few studies showed the relationship between the value of myocardial injury marker after the RFCA and relevant factors. AF patients who underwent primary RFCA were enrolled from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. The relationship between hs-TnI after the RFCA and PV reconnection (PVR) was evaluated. The impact of relevant factors, including baseline patient characteristics, detail of procedure on myocardial injury was investigated. This study included 407 patients (median age was 71 years, the ratio of female was 30.7%). Late arrhythmia recurrence was observed in 111 patients (27.3%) and 66 patients were underwent repeated ablation. PVR was observed in 33 patients (50.0%). The hs-TnI level was significantly lower in the patients with PVR than those without PVR (1.150 ng/ml vs 1.921 ng/ml, p = 0.040). Paroxysmal AF and age were significantly associated with acute myocardial injury after the RFCA (standardized beta coefficient = 0.206 and p < 0.001, standardized beta coefficient = - 0.114 and p = 0.043, respectively). The hs-TnI after RFCA was significantly higher in PAF patients than PerAF (p < 0.001), even if application number and total application time were taken into consideration. Acute myocardial injury after RFCA was significantly lower in the patients with PVR than those without PVR. Age and AF type were significantly and strongly associated with acute myocardial injury after the RFCA., (© 2021. Springer Japan KK, part of Springer Nature.)

Background: The detailed electrophysiological characteristics of atrial fibrillation (AF) initiating non-pulmonary vein (PV) triggers excluding origins from the superior vena cava (SVC) and left atrial posterior wall (LAPW) (Non-PV-SVC-LAPW triggers) remain unclear. This study aimed to clarify the detailed electrophysiological characteristics of non-PV-SVC-LAPW triggers., Methods: Among 446 AF ablation procedures at 2 institutions, patients with reproducible AF initiating non-PV-SVC-LAPW triggers were retrospectively enrolled. The trigger origin was mapped using the self-reference mapping technique. The following electrophysiological parameters were evaluated: the voltage during sinus rhythm and at the onset of AF at the earliest activation site, coupling interval of the trigger between the prior sinus rhythm and AF trigger, and voltage change ratio defined as the trigger voltage at the onset of AF divided by the sinus voltage., Results: Detailed electrophysiological data were obtained at 28 triggers in 21 patients. The median trigger voltage at the onset of AF was 0.16mV and median trigger coupling interval 182msec. Normal sinus voltages (≧0.5mV) were observed at 16 triggers and low voltages (<0.5mV) at 12 triggers. The voltage change ratio was significantly lower for the normal sinus voltage than low sinus voltage (0.20 vs. 0.60, p = 0.002). The trigger coupling intervals were comparable between the normal sinus voltage and low sinus voltage (170ms vs. 185ms, p = 0.353)., Conclusions: The trigger voltage at the onset of AF was low, regardless of whether the sinus voltage of the trigger was preserved or low., Competing Interests: The authors have declared that no competing interests exist.

Background: Cryoballoon ablation (CBA) and laser balloon ablation (LBA) were developed as alternatives to conventional radiofrequency ablation for paroxysmal atrial fibrillation (PAF). Pathological findings after ablation such as myocardial injury and inflammation are thought to be different between CBA and LBA. However, the different impact of myocardial injury and inflammation after ablation on short- and mid-term outcomes remains unclear., Methods: Consecutive PAF patients who underwent CBA and LBA were enrolled from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. The difference of the acute myocardial injury marker (hs-TnI), and changes of inflammation markers (C reactive protein; ΔCRP, and white blood cell; ΔWBC) after catheter ablation and the difference of the short-term (within 3 months after ablation) and mid-term (from 3 months to 6 months after ablation) outcomes were evaluated between the two groups., Results: The CBA and LBA groups consisted of 55 and 56 patients, respectively. After propensity score matching, CBA and LBA groups consisted of 37 patients, respectively. Hs-TnI value was significantly higher in CBA than LBA group, while ΔCRP and ΔWBC were significantly higher in LBA than CBA group. In the propensity score-matched pairs, the LBA group had a significantly greater risk of short-term arrhythmia recurrence than the CBA group, whereas no significant difference of mid-term arrhythmia recurrence were found between the two groups., Conclusion: Myocardial injury and inflammation status differ between CBA and LBA groups. LBA group had stronger inflammation after ablation and had a significantly greater risk of short-term arrhythmia recurrence after PVI than CBA group., Competing Interests: Declaration of competing interest None., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Right bundle branch block (RBBB) is one of the most frequent alterations of the electrocardiogram. Several studies have shown that RBBB is a risk factor of cardiovascular diseases. However, the clinical outcomes after pulmonary vein isolation (PVI) in patients with RBBB remain unclear. We enrolled consecutive atrial fibrillation (AF) patients who underwent PVI from the Osaka Rosai Atrial Fibrillation (ORAF) registry. We excluded patients with other wide QRS morphologies (left bundle branch block, ventricular pacing, and unclassified intraventricular conduction disturbances) and divided them into 2 groups: RBBB (QRS duration ≥120msec) and No-RBBB (QRS duration <120) groups. We compared the incidence of late recurrence of AF and/or atrial tachycardia (AT) (LRAF) between the 2 groups using a propensity score-matched analysis and evaluated the risk of LRAF using Cox regression model. We finally analyzed 671 consecutive AF patients. The RBBB group consisted of 50 patients (7.5%) and the No-RBBB group of 621 patients. Median follow-up duration was 734 [496, 1,049] days. Hypertension and diabetes mellitus were significantly higher in RBBB group than No-RBBB group. Among the 46 matched patients pairs, Kaplan-Meier analysis demonstrated that RBBB group had a significantly greater risk of LRAF than the No-RBBB group (p = 0.046). The Cox regression model revealed significantly higher risks of LRAF (HR, 2.30; 95% CI, 1.00 to 5.33; p=0.044) in RBBB group compared with No-RBBB group. Non-PV AF triggers were significantly higher in RBBB group than No-RBBB group (p = 0.048). In conclusion, RBBB can be an important predictor of LRAF after PVI., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Various predictors of atrial fibrillation (AF) recurrence have been shown based on the baseline characteristics before catheter ablation (CA). This study aimed to develop a novel scoring system for predicting very late recurrences of AF (VLRAFs) after an initial CA, taking the postprocedural clinical data into account and reassessing VLRAFs in 12-month patients' condition using previously known preprocedural predictors of AF recurrences. We retrospectively studied 327 patients who underwent an initial CA with freedom from AF for over 12 months. We elucidated the predictors of VLRAFs and created a new score to predict VLRAFs in the discovery AF cohort (n = 181). Thereafter, we investigated whether the new scoring system could accurately predict VLRAFs in the validation AF cohort (n = 146). In the discovery AF cohort, VLRAFs were observed in 53 patients (29%) during the follow-up period (mean follow-up duration: 55 months). The univariate and multivariate Cox proportional-hazards model demonstrated that non-pulmonary vein foci, early recurrences of AF (ERAFs), atrial premature contraction (APC) burden ≥ 142/24 hours, and minimum prematurity index of the APCs ≤ 48% were associated with VLRAFs after CA. We created a new scoring system to predict VLRAFs, the n-PReDCt score (non-pulmonary vein: 1 point, early recurrences of AFs (Recurrences of AF in early phase after CA): 1 point, APC burden ≥ 142/24 hours: 1 point, and minimum prematurity index (= Coupling interval) of the APCs of ≤ 48%: 1 point). The n-PReDCt score was significantly associated with VLRAFs by a Kaplan-Meier analysis in the discovery AF and validation AF cohorts (p < 0.0001 and p < 0.0001, respectively)., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The method to perform a precise mapping of non-pulmonary vein (PV) triggers has not been fully investigated. The purpose of this study was to assess the efficacy of self-reference mapping for eliminating non-PV triggers in a large series of patients including the long-term outcomes., Method: Among 446 atrial fibrillation (AF) ablation procedures in 431 patients at 2 institutions, we prospectively enrolled patients who had reproducible non-PV triggers. Non-PV triggers from the left atrial posterior wall (LAPW) and superior vena cava (SVC) were excluded. Ablation procedure and long-term clinical outcomes were evaluated. The origin of non-PV triggers were detected using a self-reference mapping technique, which does not require any other reference catheters. Instead of using signals obtained from a fixed intracardiac catheter as the reference, an operator repeatedly moved a multi-electrode catheter to the earliest site creating a new reference each time to map the non-PV trigger., Results: A total of 32 non-PV triggers excluding origins from the LAPW and SVC were induced in 23 patients. All triggers were mapped using a self-reference mapping technique with 11.0 ± 10.2 min and eliminated by radiofrequency ablation with 10.7 ± 10.0 points application. No major complications were observed. During the follow-up (529 ± 270 days), 18 patients (77%) were free from atrial tachyarrhythmias after a 3-month blanking period. Three patients received additional ablation procedures. No non-PV triggers ablated during the previous procedure were observed., Conclusions: A novel self-reference mapping technique is useful for eliminating non-PV triggers for the short- and long-term outcomes., Competing Interests: Declaration of competing interest The authors declare no conflict of interest for this article., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Backgrounds: Several studies have shown the serum high sensitive cardiac troponin I (hs-TnI) a biomarker of myocardium injury, and C-reactive protein (CRP), a biomarker of inflammation, are associated with worse cardiovascular outcomes. We evaluated the relationship between the hs-TnI level in patients with paroxysmal atrial fibrillation (PAF) after pulmonary vein isolation (PVI) and atrial fibrillation (AF) recurrence., Methods and Results: We enrolled 263 consecutive PAF patients who underwent PVI from May 2017 to April 2018. We investigated the difference in the relationship between the myocardial injury marker (serum hs-TnI), inflammatory marker (CRP, white blood cell) at 36 to 48 hours after the PVI, and early or late recurrence of AF (ERAF; <3 months and LRAF; from 3 months to 1 year) between the radiofrequency ablation group (R group) and cryoballoon ablation group (C group). The R group consisted of 147 patients and the C groups consisted of 116 patients. The serum hs-TnI level in R group was significantly lower than in the C group (2.33 vs 5.08 ng/mL; P < .001), while the CRP was significantly higher in the R group than C group (2.02 vs 1.10 mg/dL; P < .001). The incidences of an ERAF/LRAF were similar between the two groups., Conclusion: Cryoballoon ablation may cause more myocardial injury than radiofrequency catheter ablation, on the contrary, radiofrequency catheter ablation, may cause more inflammation than cryoballoon ablation. However, these phenomena may not affect the recurrence of AF after the PVI in patient with PAF., (© 2020 Wiley Periodicals, Inc.)

We report the autopsy case of 68-year-old woman who received cryoballoon (CB) ablation for paroxysmal atrial fibrillation 7 months before death. Both macroscopic and microscopic findings revealed no thrombus formation around pulmonary veins. Previous experimental studies have shown the lower risk of thrombus formation in CB ablation as compared to radiofrequency ablation. Our findings in the human autopsy case may support this merit of CB ablation. To confirm this benefit of CB ablation, further studies regarding histopathology of CB ablation should be performed., (© 2019 Wiley Periodicals, Inc.)

The article describes the case of a 79-year-old man with ischemic heart disease who underwent catheter ablation of persistent atrial tachycardia (AT). The man received a pulmonary vein isolation, left atrial (LA) posterior wall isolation, and lateral mitral isthmus linear ablation of atrial fibrillation and AT. Also discussed are the earliest activation site in the LA and the need of physicians to pay attention when using AT entertainment pacing in macro-reentrant tachycardias.