Impact of combining ablation index-guided and very high-power short-duration ablation at posterior wall adjacent to esophagus during perioperative period on procedural factors.

INTRODUCTION: The impact of combining ablation index (AI)-guided and very high-power short-duration (vHPSD) ablation on procedural factors at the posterior wall near the esophagus is unclear. METHODS: Atrial fibrillation patients who underwent initial ablation using three-dimensional mapping were enrolled. Patients were classified into two groups: those who underwent only AI-guided pulmonary vein isolation (PVI) (AI group) and those who underwent vHPSD ablation at the posterior wall adjacent to the esophagus in addition to AI-guided PVI (AI + vHPSD group). Differences in myocardial injury, inflammation, procedural characteristics, and pulmonary vein (PV) reconnection patterns were assessed between the two groups. RESULTS: This study included 167 patients (AI group, 83 patients; AI+vHPSD group, 84 patients). No significant differences in high-sensitive troponin I or changes in inflammatory markers between pre- and Postablation were observed in either group. Total application time and total application energy were significantly lower in the AI+vHPSD group than in the AI group (p < 0.001 for both) despite no significant difference in the total number of applications between the groups. The incidence of esophagus temperature ≥40 degrees was significantly lower in the AI+vHPSD group than in the AI group (p = 0.036). However, the incidence of PV reconnections near the esophagus was significantly higher in the AI+vHPSD group than in the AI group (11.9% vs 3.6%, p = 0.046), despite no significant difference in the incidence of PV reconnections overall. CONCLUSION: The combination of AI-guided PVI and vHPSD adjacent to the esophagus demonstrated reduced application energy requirements and maintained safety and effectiveness during the perioperative period.

Is sinus rhythm maintenance after repeat catheter ablation effective in patients with atrial fibrillation and heart failure with preserved ejection fraction?

BACKGROUND: Heart failure (HF) with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are associated with high morbidity and mortality. Recently, sinus rhythm (SR) maintenance (SRM) after catheter ablation (CA) of AF (AFCA) in HFpEF has shown to reduce adverse events as compared to medical treatment. However, it remains unclear whether SRM after a repeat CA for recurrent AF has the same effect as SRM after the initial CA in patients with AF and HFpEF. METHODS AND RESULTS: We studied 244 AF patients with HFpEF who maintained SR after repeat AFCA (repeat CA-SRM group, n = 54) and initial AFCA (initial CA-SRM group, n = 190). HFpEF were defined as HFA-PEFF score of 5 or 6 and left ventricular ejection fraction ≥ 50% before the initial CA. The primary endpoint was a composite of all-cause mortality, HF hospitalizations, or strokes within 3 years after the initial or repeat CA. The incidence of the primary endpoint was similar between the repeat CA-SRM and initial CA-SRM groups (3 of 54 [5.6%] vs. 8 of 190 [4.2%], p = .423 by a log-rank test). There was no significant difference in the 12-month HFA-PEFF score and the proportion of a 12-month HFA-PEFF score <5 between the repeat CA-SRM and the initial CA-SRM groups (5 [4,6] vs. 5 [4,6], p = .915, and 46% vs. 35%, p = .426, respectively). CONCLUSIONS: In patients with AF and HFpEF diagnosed by HFA-PEFF score, the primary endpoint of all-cause mortality, HF hospitalizations, and strokes was similar between the repeat CA-SRM and initial CA-SRM groups.

Difference between antegrade and retrograde orbital atherectomy system debulking using an artificial pulsatile heart model.

BACKGROUND: Debulking devices are necessary to treat severe calcified lesions. OAS has a unique characteristic that the burr moves forward and backward. There are few studies reporting the differences of ablation style between only-antegrade and only-retrograde OAS. AIMS: The aim of this study was to evaluate the difference of ablation style between only-antegrade and only-retrograde orbital atherectomy system (OAS) using an artificial pulsatile heart model (HEARTROID system®) and optical coherence tomography (OCT). METHODS: The calcified lesion model was inserted into the mid of left anterior descending in the HEARTROID®. Only-antegrade and only-retrograde ablation of OAS were conducted for each five lesions. Pre-OCT, OCT after low speed debulking and OCT after high speed debulking were conducted. The width and the depth of debulked area, the debulked area and the direction of debulked area were investigated. RESULTS: In all of 210 cross-sections, 91 debulked cross sections were chosen for analysis. Only-antegrade group had 47 debulked cross-sections, and only-retrograde group 44 cross-sections. In the evaluation of OCT after high speed debulking, the debulked area (0.76 mm2 [0.58-0.91] vs. 0.53 mm2 [0.36-0.68], p < 0.001) and the depth of debulked area (0.76 mm [0.58-0.91] vs. 0.53 mm [0.36-0.68], p < 0.001) were significantly higher in only-antegrade group compared to only-retrograde group. The debulked bias and the width of debulked area are not significantly different between the two groups. CONCLUSIONS: Compared to only-retrograde debulking, only-antegrade debulking acquired larger debulked area because of larger cutting depth, although the debulked bias and the width of debulked area were comparable between the two groups.

Impact of 12-Month Angioscopic Thrombi and Yellow Plaque After Drug-Eluting Stent Implantation.

BACKGROUND: Coronary angioscopy (CAS) has 2 unique abilities: direct visualization of thrombi and plaque color. However, in the recent drug-eluting stent (DES) era, serial CAS findings after DES implantation have not been fully elucidated. We investigated the impact of CAS findings after implantation of a polymer-free biolimus A9-coated stent (PF-BCS) or durable polymer everolimus-eluting stent (DP-EES). METHODS AND RESULTS: We investigated serial CAS and optical coherence tomography (OCT) findings at 1 and 12 months in 99 patients who underwent PF-BCS or DP-EES implantation. We evaluated factors correlated with angioscopic thrombi and yellow plaque, and the clinical impact of both thrombi and yellow plaque at 12 months (BTY). The BTY group included 17 (22%) patients. The incidence and grade of thrombi and yellow plaque decreased from 1 to 12 months. Although no patients had newly appearing thrombi at 12 months, 2 DP-EES patients had newly appearing yellow plaque at 12 months. Multivariable analysis revealed HbA1c, minimum stent area, and adequate strut coverage were significant factors correlated with 12-month angioscopic thrombi, and DP-EESs were significantly correlated with 12-month yellow plaque. However, BTY was not correlated with clinical events. CONCLUSIONS: The management of diabetes, stent area, and adequate stent coverage are important for intrastent thrombogenicity and polymer-free stents are useful for stabilizing plaque vulnerability.

Appropriate Selection of Substrate Ablation for Persistent Atrial Fibrillation Using Intraprocedural Assessment.

BACKGROUND: It has not been fully elucidated which patients with persistent atrial fibrillation (PerAF) should undergo substrate ablation plus pulmonary vein isolation (PVI). This study aimed to identify PerAF patients who required substrate ablation using intraprocedural assessment of the baseline rhythm and the origin of atrial fibrillation (AF) triggers. METHODS AND RESULTS: This was a post hoc subanalysis using extended data of the EARNEST-PVI trial, a prospective multicenter randomized trial comparing PVI-alone and PVI-plus (i.e., PVI with added catheter ablation) arms. We divided 492 patients into 4 groups according to baseline rhythm and the location of AF triggers before PVI: Group A (n=22), sinus rhythm with pulmonary vein (PV)-specific AF triggers (defined as reproducible AF initiation from PVs only); Group B (n=211), AF with PV-specific AF triggers; Group C (n=94), sinus rhythm with no PV-specific AF trigger; Group D (n=165), AF with no PV-specific AF trigger. Among the 4 groups, only in Group D (AF at baseline and no PV-specific AF triggers) was arrhythmia-free survival significantly lower in the PVI-alone than PVI-plus arm (P=0.032; hazard ratio 1.68; 95% confidence interval 1.04-2.70). CONCLUSIONS: Patients with sinus rhythm or PV-specific AF triggers did not receive any benefit from substrate ablation, whereas patients with AF and no PV-specific AF trigger benefited from substrate ablation.

Changes in QRS morphology during antidromic atrioventricular reentrant tachycardia.

We report a case of a 44-year-old male who underwent an electrophysiological study for symptomatic supraventricular tachycardia (SVT) with wide QRS complex. The SVT was diagnosed as an antidromic atrioventricular reentrant tachycardia (AVRT) via antegrade conduction of left-sided accessory pathway (AP). However, the QRS morphology changed during the SVT, and then the SVT was terminated spontaneously. The mapping of AP was performed during sinus rhythm, and the radiofrequency application successfully eliminated the AP, which rendered tachycardias non-inducible. This was a rare case of antidromic AVRT during which the QRS morphology changed.

Risk factors for tachycardia-induced cardiomyopathy due to atrial fibrillation.

BACKGROUND: Tachycardia-induced cardiomyopathy (TIC) is a reversible cardiomyopathy with ventricular dysfunction caused by tachyarrhythmias. Notably, atrial fibrillation (AF) is the most common causal arrhythmia leading to TIC. However, the risk factors for the development of TIC due to AF remain unclear. This study aimed to identify the associated factors of TIC due to AF. METHODS: Persistent AF patients with heart rate (HR) ≥100 beats per minute who underwent initial catheter ablation were enrolled in this study. TIC was diagnosed as left ventricular ejection fraction (LVEF) < 50% during AF rhythm, which was recovered after the restoration of sinus rhythm. Non-TIC was defined as LVEF ≥ 50% despite AF rhythm. The patient backgrounds were compared between the TIC group and the non-TIC group to reveal the contributing factors of TIC. RESULTS: The TIC group comprised 57 patients, while the non-TIC group consisted of 101 patients. The TIC group was younger than the non-TIC group (median 64 vs. 70, p = 0.006). Male sex was more frequent in the TIC group than the non-TIC group (82.5% vs. 58.4%, p = 0.003). HR was higher in the TIC group than in the non-TIC group (median 130 bpm vs. 111 bpm, p < 0.001). The number of smokers was significantly higher in the TIC group than in the non-TIC group (p < 0.001). Multivariable analysis demonstrated that higher HR (odds ratio [OR]: 1.74; 95% confidence interval [CI]: 1.37-2.21; p < 0.001) and current smokers (OR: 5.27; 95% CI: 1.60-17.4; p = 0.006) were the independent factors leading to TIC. CONCLUSION: Higher HR and current smokers were independent risk factors for the development of TIC due to AF.

Prognostic significance of ratio of P-wave duration to P-wave vector magnitude for mortality in acute anterior myocardial infarction.

BACKGROUND: The impact of P-wave abnormality in acute anterior MI, where the culprit vessel is the left anterior descending artery, remains undetermined. This study aimed to elucidate the impact of P-wave morphology on clinical outcomes in acute anterior MI. METHODS: Patients undergoing emergent percutaneous coronary intervention for acute anterior MI were enrolled between September 2014 and April 2019 (derivation cohort) and May 2019 through July 2023 (validation cohort). P-wave duration (Pd) and P-wave vector magnitude (Pvm) were measured. The Pvm was calculated as the square root of the sum of the squared P-wave magnitudes in leads II and V6 and one-half of the P-wave amplitude in V2. The patients were categorized into high and low Pd/Pvm groups using a statistically derived cut-off value. The endpoint comprised the composite of heart failure (HF) hospitalization and all-cause death. RESULTS: Consecutive 426 patients were enrolled in this study (derivation cohort, 213 patients; validation cohort, 216 patients). The calculated cut-off value of Pd/Pvm for predicting the clinical endpoint, determined through receiver operating curve analysis, was 793.5 ms/mV (area under the curve [AUC] = 0.85, sensitivity of 73.8 %, and specificity of 94.0 %) in the derivation cohort. Kaplan-Meier analyses revealed a significantly higher risk of the endpoint in patients with high Pd/Pvm than those with low Pd/Pvm in derivation and validation cohorts (Log-rank p < 0.001 and p < 0.001, respectively). Multivariate Cox proportional hazards analysis identified advanced age, elevated Pd/Pvm, and reduced left ventricular ejection fraction as independent and significant factors associated with the endpoint in the validation cohort (p = 0.008, p < 0.001, and p < 0.001, respectively). CONCLUSION: High Pd/Pvm was significantly associated with the composite of HF hospitalization and all-cause death after acute anterior MI.

Visualization of residual gaps after linear ablation using the LUMIPOINTTM module: A case report.

BACKGROUND: Macroreentrant atrial tachycardia (ATs) through epicardial conduction is depicted as a focal AT on 3-D mapping, i.e., pseudo-focal AT. A new feature of the Rhythmia mapping system (Boston Scientific), the "LUMIPOINT module", can highlight all electrocardiograms (EGMs) above a threshold determined by an adjustable confidence slider (CS). Lowering the CS (L-CS) may highlight undetected electrograms (EGMs) at the nominal CS setting, potentially enabling visualization of the critical isthmus of pseudo-focal ATs. METHODS AND RESULTS: This study included 3 ATs after linear ablation of two left atrial roof-dependent ATs (cases 1 and 2) and one peri-mitral flutter (case 3). All ATs were diagnosed as pseudo-focal AT according to an electrophysiological study and the Rhythmia mapping system with the LUMIPOINT module. The L-CS method consisted of the following steps: 1. Set the LUMIPOINT activation window to the time difference before and after the linear ablation line. 2. Highlight the two regions before and after the linear ablation line. 3. Gradually lower the CS value from the nominal setting of 85 % by 5-10 %. By the L-CS method in cases 1-3, the 2-sided highlighted areas before and after the prior linear ablation lesion gradually expanded and eventually fused. EGMs at the fusion sites of the highlighted areas exhibited fragmented EGMs with a low voltage, where a single-shot ablation terminated the targeted ATs. CONCLUSION: The L-CS method was useful for the visualization of residual gaps and identification of targeted ablation sites in cases of pseudo-focal AT after linear ablation of macroreentrant ATs.

Predictors and outcomes of tricuspid regurgitation improvement after radiofrequency catheter ablation for persistent atrial fibrillation.

INTRODUCTION: Little has been reported on the predictors and outcomes of improvement of tricuspid regurgitation (TR) after radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (AF). METHODS: We enrolled 141 patients with persistent AF and moderate or severe TR assessed by transthoracic echocardiography (TTE) who underwent an initial RFCA between February 2015 and August 2021. These patients underwent follow-up TTE at 12 months after the RFCA, and were categorized into two groups based on the improvement (defined as at least one-grade improvement of TR) and non-improvement of TR: IM group and Non-IM group, respectively. We compared the patient characteristics, ablation procedures, and recurrences after the RFCA between the two groups. In addition, we examined the major event (defined as admission for heart failure or all-cause death) more than 12 months after the RFCA. RESULTS: IM group consisted of 90 patients (64%). A multivariate analysis revealed that age <71 years old and absence of late recurrence (LR, defined as recurrence of atrial tachyarrhythmia between 3 and 12 months after the RFCA) were independently associated with the improvement of TR after the RFCA. Furthermore, IM group had the higher incidence of major event-free survival than Non-IM group. CONCLUSIONS: Relatively young age and absence of LR were good predictors of improvement of TR after the RFCA for persistent AF. In addition, the improvement of TR was related to better clinical outcomes.

Impact of calcified nodule on target lesion failure after stent implantation in hemodialysis patients.

BACKGROUND: Little is known about intravascular imaging predictors of cardiac events after drug-eluting stent (DES) implantation in hemodialysis (HD) patients. We aimed to reveal the association between calcified nodules (CN) and target lesion failure (TLF) in HD patients after DES implantation. METHODS: We enrolled 114 HD patients who underwent DES implantation between October 2016 and October 2020. The patients were divided into a CN group (39%, 44 patients) and a non-CN group (61%, 70 patients). The primary endpoint was the incidence of TLF, including cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization. RESULTS: HD duration was longer, and the calcium burden was higher in the CN group than in the non-CN group. Over a median follow-up of 607 days [interquartile range: 349-965 days], the cumulative incidence curve showed that the CN group had a significantly higher incidence of TLF than the non-CN group (31.8% vs. 11.4% within 3 years, p = 0.008).　On Fine-Gray sub-distribution hazard model analysis, the CN group was associated with an increased rate of TLF (hazard ratio [HR]: 2.86; 95% confidence interval [CI]: 1.21-6.75, p = 0.016). An in-stent CN was observed in 73% of the lesions with target lesion revascularization in the CN group, whereas no in-stent CN was observed in the non-CN group (p = 0.026). CONCLUSIONS: CN was an independent predictor of TLF in patients undergoing HD. In-stent CN was an important cause of TLF after DES implantation in CN lesions in HD patients; therefore, a different strategy should be considered for treating the lesions.

Prognostic Comparison of Octogenarian vs. Non-Octogenarian With Acute Decompensated Heart Failure　- AURORA Study.

BACKGROUND: Acute decompensated heart failure (ADHF) is the main cause of hospitalization and death of octogenarians, but no data on the 1-year post-discharge mortality rate. We evaluated the clinical status and predictors of 1-year mortality in octogenarians with ADHF.Methods and Results: From the AURORA (Acute Heart Failure Registry in Osaka Rosai Hospital) study, we examined 1,246 hospitalized ADHF patients. We compared the in-hospital mortality rate and the proportion of heart failure (HF) with preserved ejection fraction (HFpEF) between octogenarians and non-octogenarians. After discharge we compared the 1-year mortality rate between these groups, and we also evaluated the predictors of death in both groups. The proportion of HFpEF among the in-hospital deaths of octogenarians was significantly higher than in non-octogenarians (46.2% vs. 15.0%, P=0.031). The 1-year mortality rate after discharge was significantly higher in the octogenarians than non-octogenarians (P=0.014). Multivariable Cox regression analysis revealed that albumin ≤3.0 g/dL and antiplatelet agents were useful predictors of 1-year death after discharge of octogenarians whereas chronic kidney disease was a predictor in the non-octogenarians. CONCLUSIONS: The proportion of HFpEF among in-hospital deaths of octogenarians with ADHF was high as compared with non-octogenarians. When octogenarians with ADHF have severe hypoalbuminemia and antiplatelet agents, early nutritional and medical interventions after discharge may be important to improve the 1-year prognosis.

Dual Antiplatelet Therapy Duration After Multivessel Optimal Intravascular Ultrasound-Guided Percutaneous Coronary Intervention.

BACKGROUND: There is a scarcity of data evaluating contemporary real-world dual antiplatelet therapy (DAPT) strategies after percutaneous coronary intervention (PCI).Methods and Results: In the OPTIVUS-Complex PCI study multivessel cohort enrolling 982 patients undergoing multivessel PCI, including left anterior descending coronary artery using intravascular ultrasound (IVUS), we conducted 90-day landmark analyses to compare shorter and longer DAPT. DAPT discontinuation was defined as withdrawal of P2Y12inhibitors or aspirin for at least 2 months. The prevalence of acute coronary syndrome and high bleeding risk by the Bleeding Academic Research Consortium were 14.2% and 52.5%, respectively. The cumulative incidence of DAPT discontinuation was 22.6% at 90 days, and 68.8% at 1 year. In the 90-day landmark analyses, there were no differences in the incidences of a composite of death, myocardial infarction, stroke, or any coronary revascularization (5.9% vs. 9.2%, log-rank P=0.12; adjusted hazard ratio, 0.59; 95% confidence interval, 0.32-1.08; P=0.09) and BARC type 3 or 5 bleeding (1.4% vs. 1.9%, log-rank P=0.62) between the off- and on-DAPT groups at 90 days. CONCLUSIONS: The adoption of short DAPT duration was still low in this trial conducted after the release of the STOPDAPT-2 trial results. The 1-year incidence of cardiovascular events was not different between the shorter and longer DAPT groups, suggesting no apparent benefit of prolonged DAPT in reducing cardiovascular events even in patients who undergo multivessel PCI.

Impact of Structural Abnormalities in Left Ventricle and Left Atrium on Clinical Outcomes in Heart Failure with Preserved Ejection Fraction.

Two key echocardiographic parameters, left ventricular mass index (LVMI) and left atrial volume index (LAVI), are important in assessing structural myocardial changes in heart failure (HF) with preserved ejection fraction (HFpEF). However, the differences in clinical characteristics and outcomes among groups classified by LVMI and LAVI values are unclear.We examined the data of 960 patients with HFpEF hospitalized due to acute decompensated HF from the PURSUIT-HFpEF registry, a prospective, multicenter observational study. Four groups were classified according to the cut-off values of LVMI and LAVI [LVMI = 95 g/m2 (female), 115 g/m2 (male) and LAVI = 34 mL/m2]. Clinical endpoints were the composite of HF readmission and all-cause death. Study endpoints among the 4 groups were evaluated. The composite endpoint occurred in 364 patients (37.9%). Median follow-up duration was 445 days. Kaplan-Meier analysis revealed significant differences in the composite endpoint among the 4 groups (P < 0.001). Cox proportional hazards analysis demonstrated that patients with increased LAVI alone were at significantly higher risk of HF readmission and the composite endpoints than those with increased LVMI alone (P = 0.030 and P = 0.024, respectively). Age, male gender, systolic blood pressure at discharge, atrial fibrillation (AF) hemoglobin, renal function, and LAVI were significant determinants of LVMI and female gender, AF, hemoglobin, and LVMI were significant determinants of LAVI.In HFpEF patients, increased LAVI alone was more strongly associated with HF readmission and the composite of HF readmission and all-cause death than those with increased LVMI alone.

High-density activation map of atrial tachycardia within left atrial appendage.

Identification of the critical isthmus of the reentrant tachycardia is essential to maximize the effect of catheter ablation (CA) and to minimize the myocardial injury of CA. An 81-year-old woman presented recurrent palpitations after CA of atrial fibrillation (AF) and atrial tachycardia (AT). She had moderate aortic valve stenosis and coronary artery disease. She had received a pulmonary vein isolation, left atrial (LA) posterior wall isolation, and LA anterior linear ablation for atrial fibrillation 1 year prior. At the start of the procedure, she was in sinus rhythm. Atrial burst pacing induced an AT (230msec). High-density mapping revealed a figure-of-eight activation pattern within the LA appendage (LAA), accounting for 99% of the tachycardia cycle length. The critical isthmus was identified at the mid LAA and the local electrogram of the critical isthmus was not fractionated. A single radiofrequency application at the critical isthmus of the AT, terminated the AT. She was free from any ATs for 28 months. Radiofrequency ablation of the localized reentrant AT was usually performed targeting long fractionated electrograms. In our case, the local electrogram at the critical isthmus was not fragmented compared with the LAA distal part. Long fractionated electrograms were recorded at a more distal part of the LAA than the common isthmus and we could avoid the potential risk of a perforation. A recent developed 3-dimensional electro-anatomical mapping system can identify the critical isthmus and allow us to select a new therapeutic strategy for a critical isthmus ablation of an AT within the LAA.

Comparison of 1-Month and 12-Month Vessel Responses Between the Polymer-Free Biolimus A9-Coated Stent and the Durable Polymer Everolimus-Eluting Stent.

BACKGROUND: A polymer-free biolimus A9-coated stent (PF-BCS) may achieve better arterial healing than a durable polymer drug-eluting stent owing to its polymer-free feature.Methods and Results: This multicenter, prospective, observational study enrolled 105 patients (132 lesions) who underwent PF-BCS (51 patients, 71 lesions) or durable polymer everolimus-eluting stent (DP-EES, 54 patients, 61 lesions) implantation. Serial coronary angioscopy (CAS) and optical coherence tomography (OCT) examinations were performed at 1 and 12 months, and the serial vessel responses were compared between PF-BCS and DP-EES. The primary outcome measure was the incidence of subclinical intrastent thrombus on CAS. The secondary outcome measures were: adequate strut coverage (≥40 µm) on OCT and maximum yellow color grade on CAS. The incidence of thrombus was high at 1 month (100% vs. 93%, P=0.091), but decreased at 12 months (18% vs. 25%, P=0.56), without a significant difference between PF-BCS and DP-EES. The adequate strut coverage rate was significantly higher (84±14% vs. 69±22%, P<0.001) and yellow color was significantly less intense (P=0.012) at 12 months in PF-BCS than in DP-EES; however, they were not significantly different at 1 month (adequate strut coverage: 47±21% vs. 50±17%, P=0.40; yellow color: P=0.99). CONCLUSIONS: Although the thrombogenicity of PF-BCS was similar to that of DP-EES, the adequate coverage and plaque stabilization rates of PF-BCS were superior to those of DP-EES at 12 months.

Impact of very early recurrence of atrial fibrillation after cryoballoon ablation.

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.

The correlation between local impedance drop and catheter contact in clinical pulmonary vein isolation use.

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 (ß = 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.

Impact of radiofrequency catheter ablation for atrial fibrillation in patients with left atrial enlargement.

Little has been reported on the impact of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in patients with left atrial enlargement (LAE). A total of 706 patients underwent an initial RFCA for AF between September 2014 and September 2019 in our hospital. These patients were categorized into two groups according to the pre-procedural left atrial diameter (LAD) measured by transthoracic echocardiography (TTE): LAE group with LAD ≥ 50 mm and non-LAE group with LAD < 50 mm. We compared the patient characteristics, ablation procedures, and late recurrence of AF (LRAF, defined as a recurrence of atrial tachyarrhythmia between 3 and 12 months after the RFCA) between the two groups. In addition, we performed follow-up TTE at 12 months after RFCA and investigated the factors associated with left atrium (LA) reverse remodeling in each group. LAE group and non-LAE group consisted of 155 and 551 patients, respectively. There were no significant differences in ablation procedures, procedure-related complications, and the incidence of LRAF between the two groups. Furthermore, non-PAF was identified as an independent predictor of LA reverse remodeling in LAE group by multiple regression analysis (P = 0.020). RFCA might be an effective and safe procedure even in patients with LAD ≥ 50 mm, using the contemporary 3D-guided mapping and ablation technologies. Moreover, RFCA can lead to LA reverse remodeling in 1 year if they have non-PAF before ablation.

Impact of cryoballoon contact angle and acute myocardial injury on pulmonary vein reconnection.

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.