Prevalence and characteristics of atrioventricular nodal reentrant tachycardia with a bystander concealed nodoventricular/nodofascicular pathway.

BACKGROUND: The concealed nodoventricular/nodofascicular (NV/NF) pathway is mostly a bystander, retrograde bypass tract connecting right ventricle/right bundle branch (RBB) and slow pathway (SP), which is observed in patients with atrioventricular nodal reentrant tachycardia (AVNRT). However, its prevalence and characteristics in response to pacing maneuvers have not been fully evaluated. OBJECTIVE: This study investigated the prevalence and characteristics of AVNRT with a bystander NV/NF-pathway. METHODS: We retrospectively reviewed 153 consecutive patients undergoing catheter ablation of AVNRT. Excluding 52 patients with inadequate electrophysiological data, 101 patients composed the study population. RESULTS: Three patients (3.0%) had bystander concealed NV/NF-pathways, all of which were connected to the SP. The tachycardia was typical SP/fast pathway (FP) AVNRT in two patients and atypical FP/SP AVNRT in one patient. In all cases, His-refractory ventricular extra stimuli (VESs) reset the AVNRTs with delay through the NV/NF-pathways. Ventricular overdrive pacing (VOP) in the early-phase also reset the AVNRT with delay. Earlier VESs and middle-phase of VOP did not reset the tachycardia, and further earlier VESs and late-phase of VOP reset the tachycardia with advance through the RBB-His conduction. CONCLUSION: A bystander NV/NF-pathway was not rare in patients with AVNRT. The VESs and VOP for the AVNRTs with the bystander NV/NF-pathways were characterized by the two-phase resetting phenomenon: initial transient resetting with delay through the NV/NF-pathway, and late resetting with advance through the RBB-His conduction.

Insight from the microelectrodes in case of two different types of premature ventricular contractions originating from left ventricular summit.

Premature ventricular contraction (PVC) is usually eliminated in the earliest activation site based on the conventional electrode of ablation catheter. However, the large size electrode may contain far-field potential. The QDOT MICRO ablation catheter has three micro electrodes with 0.33 mm electrode length, in addition to the conventional electrode with 3.5 mm electrode length. The micro electrodes can reflect only near-field potential. A 78-year-old with symptomatic frequent PVCs underwent catheter ablation. PVC-1 showed good pace-mapping in distal great cardiac vein (GCV). The local bipolar electrograms in the conventional electrode of ablation catheter preceded the PVC-QRS onset by 32 ms in distal GCV and 13 ms in left coronary cusp (LCC), but those in the micro electrodes preceded only by 13 ms both in distal GCV and LCC. PVC-1 was eliminated by radiofrequency (RF) application, not in distal GCV, but in LCC. PVC-2 showed good pace-mapping in LCC. The local bipolar electrograms in both the conventional electrode and the micro electrodes of ablation catheter preceded the PVC-QRS onset by 32 ms in LCC. PVC-2 was eliminated by RF application in LCC. Comparing the local electrograms of micro electrodes and the conventional electrodes may be important for identifying depth of the origin of PVCs.

Radiofrequency Catheter Ablation for Atrial Fibrillation Patients on Hemodialysis (From the Kansai Plus Atrial Fibrillation Registry)　- Clinical Impact of Early Recurrence.

BACKGROUND: Catheter ablation (CA) for atrial fibrillation (AF) in patients on hemodialysis (HD) is reported to have a high risk of late recurrence (LR). However, the relationship between early recurrence (ER) within a 90-day blanking period after CA in AF patients and LR in HD patients remains unclear.Methods and Results: Of the 5,010 patients in the Kansai Plus Atrial Fibrillation Registry, 5,009 were included in the present study. Of these patients, 4,942 were not on HD (non-HD group) and 67 were on HD (HD group). HD was an independent risk factor for LR after the initial CA (adjusted hazard ratio 1.6; 95% confidence interval 1.1-2.2; P=0.01). In patients with ER, the rate of sinus rhythm maintenance at 3 years after the initial CA was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004). However, in patients without ER, there was no significant difference in the rate of sinus rhythm maintenance at 3 years between the HD and non-HD groups (67.7% vs. 74.5%, respectively; log-rank P=0.62). CONCLUSIONS: ER in HD patients was a strong risk factor for LR. However, even HD patients could expect a good outcome without ER after the initial CA.

Prognostic Importance of B-Type Natriuretic Peptide Level in Patients Undergoing Catheter Ablation for Atrial Fibrillation.

BACKGROUND: This study assessed the prognostic importance of B-type natriuretic peptide (BNP) concentrations for clinical events after catheter ablation for atrial fibrillation (AF).Methods and Results: We enrolled 1,750 consecutive patients undergoing initial AF ablation whose baseline BNP data were available from a large-scale multicenter observational cohort (TRANQUILIZE-AF Registry). The prognostic impact of BNP concentration on clinical outcomes, including recurrent tachyarrhythmias and a composite of heart failure (HF) hospitalization or cardiac death, was evaluated. Median baseline BNP was 94.2 pg/mL. During a median follow-up of 2.4 years, low BNP (<38.3 pg/mL) was associated with lower rates of recurrent atrial tachyarrhythmias than BNP concentrations ≥38.3 pg/mL (19.9% vs. 30.6% at 3 years; P<0.001) and HF (0.8% vs. 5.3% at 3 years; P<0.001). Multivariable Cox regression analyses revealed that low BNP was independently associated with lower risks of arrhythmia recurrence (hazard ratio [HR] 0.63; 95% confidence interval [CI] 0.47-0.82; P<0.001) and HF (HR 0.17; 95% CI 0.04-0.71; P=0.002). The favorable impact of low BNP on arrhythmia recurrence was prominent in patients with paroxysmal, but not non-paroxysmal, AF, particularly among those with long-standing AF. CONCLUSIONS: Low BNP concentrations had a favorable impact on clinical outcomes after AF ablation. The heterogeneous impact of baseline BNP concentrations on arrhythmia recurrence for the subgroups of patients divided by AF type warrants future larger studies with longer follow-up periods.

Safety and Performance of the Micra VR Leadless Pacemaker in a Japanese Cohort　- Comparison With Global Studies.

BACKGROUND: The Micra leadless pacemaker has demonstrated favorable outcomes in global trials, but its real-world performance and safety in a Japan-specific population is unknown.Methods and Results: Micra Acute Performance (MAP) Japan enrolled 300 patients undergoing Micra VR leadless pacemaker implantation in 15 centers. The primary endpoint was the acute (30-day) major complication rate. The 30-day and 6-month major complication rates were compared to global Micra studies. All patients underwent successful implantation with an average follow-up of 7.23±2.83 months. Compared with previous Micra studies, Japanese patients were older, smaller, more frequently female, and had a higher pericardial effusion risk score. 11 acute major complications were reported in 10 patients for an acute complication rate of 3.33% (95% confidence interval: 1.61-6.04%), which was in line with global Micra trials. Pericardial effusion occurred in 4 patients (1.33%; 3 major, 1 minor). No procedure or device-related deaths occurred. Frailty significantly improved from baseline to follow-up as assessed by Japan Cardiovascular Health Study criteria. CONCLUSIONS: In a Japanese cohort, implantation of the Micra leadless pacemaker had a high success rate and low major complication rate. Despite the Japan cohort being older, smaller, and at higher risk, the safety and performance was in line with global Micra trials.

Tricuspid regurgitation in elderly patients with acute heart failure: insights from the KCHF registry.

AIMS: Several studies demonstrated that tricuspid regurgitation (TR) is associated with poor clinical outcomes. However, data on patients with TR who experienced acute heart failure (AHF) remains scarce. The purpose of this study is to evaluate the association between TR and clinical outcomes in patients admitted with AHF, using a large-scale Japanese AHF registry. METHODS AND RESULTS: The current study population consisted of 3735 hospitalized patients due to AHF in the Kyoto Congestive Heart Failure (KCHF) registry. TR grades were assessed according to the routine clinical practice at each participating centre. We compared the baseline characteristics and outcomes according to the severity of TR. The primary outcome was all-cause death. The secondary outcome was hospitalization for heart failure (HF). The median age of the entire study population was 80 (interquartile range: 72-86) years. One thousand two hundred five patients (32.3%) had no TR, while mild, moderate, and severe TR was found in 1537 patients (41.2%), 776 patients (20.8%), and 217 patients (5.8%), respectively. Pulmonary hypertension, significant mitral regurgitation, and atrial fibrillation/flutter were strongly associated with the development of moderate/severe of TR, while left ventricular ejection fraction <50% was inversely associated with it. Among 993 patients with moderate/severe TR, the number of patients who underwent surgical intervention for TR within 1 year was only 13 (1.3%). The median follow-up duration was 475 (interquartile range: 365-653) days with 94.0% follow-up at 1 year. As the TR severity increased, the cumulative 1 year incidence of all-cause death and HF admission proportionally increased ([14.8%, 20.3%, 23.4%, 27.0%] and [18.9%, 23.0%, 28.5%, 28.4%] in no, mild, moderate, and severe TR, respectively). Compared with no TR, the adjusted risks of patients with mild, moderate, and severe TR were significant for all-cause death (hazard ratio [95% confidence interval]: 1.20 [1.00-1.43], P = 0.0498, 1.32 [1.07-1.62], P = 0.009, and 1.35 [1.00-1.83], P = 0.049, respectively), while those were not significant for hospitalization for HF (hazard ratio [95% confidence interval]: 1.16 [0.97-1.38], P = 0.10, 1.19 [0.96-1.46], P = 0.11, and 1.20 [0.87-1.65], P = 0.27, respectively). The higher adjusted HRs of all the TR grades relative to no TR were significant for all-cause death in patients aged <80 years, but not in patients aged ≥80 years with significant interaction. CONCLUSIONS: In a large Japanese AHF population, the grades of TR could successfully stratify the risk of all-cause death. However, the association of TR with mortality was only modest and attenuated in patients aged 80 or more. Further research is warranted to evaluate how to follow up and manage TR in this elderly population.

Prognostic Value of the Severity of Clinical Congestion in Patients Hospitalized for Decompensated Heart Failure: Findings From the Japanese KCHF Registry.

BACKGROUND: Congestion is a leading cause of hospitalization and a major therapeutic target in patients with heart failure (HF). Clinical practice in Japan is characterized by a long hospital stay, which facilitates more extensive decongestion during hospitalization. We herein examined the time course and prognostic impact of clinical congestion in a large contemporary Japanese cohort of HF. METHODS AND RESULTS: Peripheral edema, jugular venous pressure, and orthopnea were graded on a standardized 4-point scale (0-3) in 3787 hospitalized patients in a Japanese cohort of HF. Composite Congestion Scores (CCS) on admission and at discharge were calculated by summing individual scores. The primary outcome was a composite of all-cause death or HF hospitalization. The median admission CCS was 4 (interquartile range, 3-6). Overall, 255 patients died during the median hospitalization length of 16 days, and 1395 died or were hospitalized for HF over a median postdischarge follow-up of 396 days. The cumulative 1-year incidence of the primary outcome increased at higher tertiles of congestion on admission (32.5%, 39.3%, and 41.0% in the mild [CCS ≤3], moderate [CCS = 4 or 5], and severe [CCS ≥6] congestion groups, respectively, log-rank P < .001). The adjusted hazard ratios of moderate and severe congestion relative to mild congestion were 1.205 (95% confidence interval [CI], 1.065-1.365; P = .003) and 1.247 (95% CI, 1.103-1.410; P < .001), respectively. Among 3445 patients discharged alive, 85% had CCS of 0 (complete decongestion) and 15% had a CCS of 1 or more (residual congestion) at discharge. Although residual congestion predicted a risk of postdischarge death or HF hospitalization (adjusted hazard ratio, 1.314 [1.145-1.509]; P < .001), the admission CCS correlated with the risk of postdischarge death or HF hospitalization, even in the complete decongestion group. No correlation was observed for postdischarge death or HF hospitalization between residual congestion at discharge and admission CCS (P for the interaction = .316). CONCLUSIONS: In total, 85% of patients were discharged with complete decongestion in Japanese clinical practice. Clinical congestion, on admission and at discharge, was of prognostic value. The severity of congestion on admission was predictive of adverse outcomes, even in the absence of residual congestion. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02334891 (NCT02334891) https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000017241 (UMIN000015238).

Atrial Fibrillation Ablation Outcomes and Heart Failure (from the Kansai Plus Atrial Fibrillation Registry).

The impact of rhythm outcomes on heart failure (HF) hospitalizations remains unknown after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). We sought to elucidate whether AF recurrence was associated with HF hospitalizations after AF RFCA. We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry), enrolling 5,010 consecutive patients (age 64 ± 10 years, 27.3% female, and 35.7% nonparoxysmal AF) who underwent an initial AF RFCA at 26 centers. The median follow-up duration was 2.9 years. The cumulative 3-year incidence of HF hospitalizations after the initial RFCA was 1.84% (0.69%/year). Hospitalized patients with HF were older with a higher prevalence of nonparoxysmal AF, renal dysfunction, diabetes, and underlying heart disease pre-RFCA. HF hospitalizations occurred more often in patients with than without recurrences (3.27 vs 0.84%, log-rank p <0.0001). After adjusting for confounders using a Cox model, AF recurrence remained an independent predictor of HF hospitalizations (hazard ratio [HR] 2.84, 95% confidence interval [CI] 1.80 to 4.47, p <0.0001). AF recurrence was a distinct HF hospitalization risk in patients with a left ventricular ejection fraction ≥50% (HR 4.54, 95% CI 2.38 to 8.65, p <0.0001) but not <50% (HR 1.31, 95% CI 0.65 to 2.62, p = 0.45), with significant interactions. Furthermore, patients with AF recurrences within 1 year had a greater HF hospitalization risk after 1 year (1.61% vs 0.79%, log-rank p = 0.019). In conclusion, AF recurrence after RFCA was independently associated with HF hospitalizations.

Impact of catheter ablation on functional tricuspid regurgitation in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) plays the main role in atrial functional tricuspid regurgitation (TR). However, the effectiveness of catheter ablation (CA) for atrial functional TR together with the mechanisms of improvement of atrial functional TR have not been fully evaluated. METHODS: We retrospectively investigated consecutive 2685 patients with AF who received CA from February 2004 to December 2019 in Kyoto University Hospital, Kyoto, Japan. The current study population consisted of 2331 patients with available transthoracic echocardiographic (TTE) data before CA (2110 patients without significant TR and 221 patients with significant TR). Among the 221 patients with significant TR, there were 64 patients with functional TR and follow-up TTE at 6-18 months after CA for AF, in whom we compared echocardiographic parameters from baseline to follow-up. RESULTS: Patients with significant TR were older, and more often women, and had more persistent AF than those without significant TR. Among the 64 patients with functional TR, TR severity and TR jet area significantly improved at follow-up (TR jet area: 5.8 [4.0-7.6] cm2 to 2.1 [1.1-3.1] cm2, P < 0.001). Moreover, mitral regurgitation jet area, left atrial area, mitral valve diameter, right ventricular end-diastolic area, right atrial area, and tricuspid valve diameter decreased at follow-up. CONCLUSIONS: TR severity and jet area improved after CA in patients with AF and significant TR. The improvement of TR might be associated with reverse remodeling of the right heart.

Catheter Ablation for Paroxysmal Atrial Fibrillation With Sick Sinus Syndrome: Insights From the Kansai Plus Atrial Fibrillation Registry.

BACKGROUND: Coexisting sick sinus syndrome (SSS) is associated with both electrical and structural atrial remodelling in patients with atrial fibrillation (AF). Limited data are available concerning catheter ablation (CA) for AF in this condition. This study investigated the efficacy of CA as a curative therapy for AF and SSS in a large-scale prospective multicentre registry. METHODS: The Kansai Plus Atrial Fibrillation (KPAF) registry enrolled 5,010 consecutive patients who underwent CA for AF; this included 3,133 patients with paroxysmal AF (mean age, 66 years; male, 69.3%; mean CHA2DS2-VASc score, 2.05±1.50; SSS, n=315 [tachy-brady syndrome, n=285]). The endpoints included the recurrence of AF with a blanking period of 90 days after CA, and de novo pacemaker implantation during the follow-up period (median duration, 2.93 years). RESULTS: The AF-free survival did not significantly differ between patients with and those without SSS (n=2,818) after the initial (log-rank p=0.864) and final sessions (log-rank p=0.268). Pacemakers were implanted in 48 patients with SSS, and implantation in this group was significantly associated with AF recurrence, including early recurrence (adjusted odds ratio, 3.57; 95% confidence interval, 1.67-7.64; p=0.002). The remaining 85.3% of patients with SSS did not require pacemaker implantation at 3 years after CA. CONCLUSIONS: Coexisting SSS did not adversely affect recurrence-free survival after CA for paroxysmal AF. Pacemaker implantation was not required in most patients with SSS, with AF recurrence serving as a strong predictor for this.

Efficacy of SubcutAneous implantable cardioVErter-defibrillators in ≤18 year-old CHILDREN: SAVE-CHILDREN registry.

BACKGROUND: In adult patients, subcutaneous implantable cardioverter defibrillators (S-ICDs) have been reported to be non-inferior to transvenous ICDs with respect to the incidence of device-related complications and inappropriate shocks. Only a few reports have investigated the efficacy of S-ICDs in the pediatric field. This study aimed to investigate the utility and safety of S-ICDs in patients ≤18 years old. METHODS: This study was a multicenter, observational, retrospective study on S-ICD implantations. Patients <18 years old who underwent S-ICD implantations were enrolled. The detailed data on the device implantations and eligibility tests, incidence of appropriate- and inappropriate shocks, and follow-up data were assessed. RESULTS: A total of 62 patients were enrolled from 30 centers. The patients ranged in age from 3 to 18 (median 14 years old [IQR 11.0-16.0 years]). During a median follow up of 27 months (13.3-35.8), a total of 16 patients (26.2%) received appropriate shocks and 13 (21.3%) received inappropriate shocks. The common causes of the inappropriate shocks were sinus tachycardia (n = 4, 30.8%) and T-wave oversensing (n = 4, 30.8%). In spite of the physical growth, the number of suitable sensing vectors did not change during the follow up. No one had any lead fractures or device infections in the chronic phase. CONCLUSIONS: Our study suggested that S-ICDs can prevent sudden cardiac death in the pediatric population with a low incidence of lead complications or device infections. The number of suitable sensing vectors did not change during the patients' growth.

Prognostic impact of catheter ablation in patients with asymptomatic atrial fibrillation.

BACKGROUND: Catheter ablation for asymptomatic atrial fibrillation (AF) remains controversial. The aim of the present study was to explore the prognostic impact of catheter ablation in asymptomatic AF patients. METHODS: We performed a post-hoc analysis of 537 risk-matched pairs of AF patients receiving first-time catheter ablation or conservative management. The primary outcome measure was a composite of cardiovascular death, heart failure (HF) hospitalization, ischemic stroke, or major bleeding. The study patients were divided into asymptomatic and symptomatic patients, and were further divided according to the presence or absence of previous AF-related complications (ischemic stroke or HF hospitalization). RESULTS: Most baseline characteristics were well balanced between the catheter ablation versus conservative management groups. The median follow-up period was 5.3 years. Catheter ablation as compared to conservative management was associated with significantly lower incidence of the primary outcome measure in the asymptomatic AF patients (14.7% versus 25.4% at 8-year, log-rank P = 0.008). However, the advantage of catheter ablation was significant only in the high-risk subset of patients with the previous AF-related complications (19.2% versus 55.6% at 8-year, log-rank P = 0.006), but not in those without (13.9% and 17.3%, P = 0.08). On the other hand, among the symptomatic AF patients, catheter ablation was associated with significantly lower incidence of the primary outcome measure regardless of the previous AF-related complications. CONCLUSIONS: In the post-hoc analysis of the matched AF cohort, catheter ablation as compared with conservative management was associated with better long-term clinical outcomes among asymptomatic AF patients only when the previous AF-related complications were present.

Stroke Risk Stratification With the CHADS2 Score in Patients Without Atrial Fibrillation Who Underwent Percutaneous Coronary Intervention.

The clinical significance of the CHADS2 score remains unclear in patients with coronary artery disease (CAD) without atrial fibrillation (AF). Therefore, the purpose of this study was to evaluate the association between the CHADS2 score and the long-term risk of ischemic stroke and its severity in patients with CAD with and without AF. Using the CREDO (Coronary Revascularization Demonstrating Outcome study)-Kyoto Registry Cohort-3, the present study population consisted of 11,516 patients with CAD who underwent percutaneous coronary intervention without oral anticoagulants at discharge. We divided the patients into 2 groups according to the presence (n = 721) or absence (n = 10,795) of AF. As the CHADS2 score increased from 0 or 1 to 6, the cumulative 5-year incidence of ischemic stroke incrementally increased from 2.1% to 17.1% in patients without AF and from 4.2% to 40.7% in patients with AF. The cumulative 5-year incidence of ischemic stroke in patients without AF and a CHADS2 score of 2 were numerically comparable to that in patients with AF and a CHADS2 score of 1 (3.4% and 3.7%). In the 423 patients who developed ischemic stroke, the modified Rankin Scale score was not significantly different between patients with and without AF (p for trend = 0.12). In patients with and without AF, the increase in the CHADS2 score was significantly associated with the greater prevalence of higher modified Rankin Scale scores (p for trend = 0.03 and <0.001, respectively). An increasing CHADS2 score was associated with an incrementally increased risk for ischemic stroke and greater severity of ischemic stroke in patients with and without AF.