Catheter ablation for patients with atrial fibrillation and heart failure with reduced and preserved ejection fraction: insights from the KiCS-AF multicentre cohort study.

AIMS: The usefulness of catheter ablation (CA) for atrial fibrillation (AF) across a broad spectrum of heart failure (HF) patients remains to be established. We assessed the association of CA with both health-related quality of life (QoL) and cardiovascular events among HF patients with reduced and preserved left ventricular ejection fraction (LVEF) in an 'all-comer' outpatient-based AF registry. METHODS AND RESULTS: Of 3303 patients with AF consecutively enrolled in a retrospective multicentre registry that mandated the Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) questionnaire at registration and 1-year follow-up, we extracted data from 530 patients complicating clinical HF. The association between CA and both 1-year change in AFEQT Overall Summary (AFEQT-OS) scores and 2-year composite clinical outcomes (including all-cause death, stroke, and HF hospitalization) was assessed by multivariable analyses. The median duration of AF was 108 days (52-218 days), and 83.4% had LVEF >35%. Overall, 75 patients (14.2%) underwent CA for AF within 1-year after registration. At 1-year follow-up, 67.2% in the ablation group showed clinically meaningful improvements of ≥ 5 points in AFEQT-OS score than 47.8% in the non-ablation group {adjusted odds ratio, 2.03 [95% confidence interval (CI): 1.13-3.64], P = 0.017}. Furthermore, the composite endpoint of all-cause death, stroke, and HF hospitalization occurred less frequently in the ablation group than the non-ablation group [adjusted hazard ratio, 0.27 (95% CI: 0.09-0.86), P = 0.027]. CONCLUSION: Among AF-HF patients, CA was associated with improved QoL and lower risk of cardiovascular events against drug therapy alone, even for patients with mildly reduced and preserved LVEF.

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

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

Efficacy of left atrial posterior wall isolation guided by lesion size prediction module for non-paroxysmal atrial fibrillation.

AIMS: The efficacy of left atrial posterior wall isolation (PWI) is controversial. Lesion durability may be a major cause of arrhythmia recurrence. The use of the lesion size prediction module improves lesion durability. This study aimed to compare the clinical outcomes of pulmonary vein isolation (PVI) alone and PWI in addition to PVI (PVI + PWI) in patients with non-paroxysmal atrial fibrillation (AF) using a lesion size prediction module. METHODS AND RESULTS: This study is a sub-analysis of the recently published prospective multicentre observational study called ALCOHOL-AF (association of alcohol consumption with outcome of catheter ablation of AF). In this sub-analysis, patients with non-paroxysmal AF in whom PVI alone or PVI + PWI was performed using the lesion size prediction module were included. Freedom from atrial tachyarrhythmia was compared between PVI alone and PVI + PWI groups using propensity score analyses. Of the 3474 patients registered in the ALCOHOL-AF study, 572 patients (age 65.6 ± 10.1 years, male 77.4%, longstanding persistent AF 25.5%) were included in this sub-analysis. We selected 212 patients treated with PVI alone and 212 treated with PVI + PWI using one-to-one propensity score matching. During the follow-up period, atrial tachyarrhythmia recurrence was documented in 92 (43.4%) and 50 (23.6%) patients in the PVI alone and PVI + PWI groups, respectively. Freedom from atrial tachyarrhythmia recurrence without anti-arrhythmic drugs after a single procedure was significantly higher in PVI + PWI than in PVI alone groups (hazard ratio: 0.452, 95% confidence interval: 0.308-0.664, P < 0.001). CONCLUSION: In this hypothesis-generating study, lesion size prediction module-guided PVI + PWI was associated with better clinical outcomes than PVI alone in patients with persistent or longstanding persistent AF.

Different Determinants of the Recurrence of Atrial Fibrillation and Adverse Clinical Events in the Mid-Term Period After Atrial Fibrillation Ablation.

BACKGROUND: It is unclear whether there are differences in the clinical factors between atrial fibrillation (AF) recurrence and adverse clinical events (AEs), including stroke/transient ischemic attack (TIA), major bleeding, and death, after AF ablation.Methods and Results:We examined the data from a retrospective multicenter Japanese registry conducted at 24 cardiovascular centers between 2011 and 2017. Of the 3,451 patients (74.1% men; 63.3±10.3 years) who underwent AF ablation, 1,046 (30.3%) had AF recurrence and 224 (6.5%) suffered AEs (51 strokes/TIAs, 71 major bleeding events, and 36 deaths) over a median follow-up of 20.7 months. After multivariate adjustment, female sex, persistent and long-lasting persistent AF (vs. paroxysmal AF), and stepwise increased left atrial diameter (LAd) quartiles were significantly associated with post-ablation recurrences. A multivariate analysis revealed that an age ≥75 years (vs. <65 years), body weight <50 kg, diabetes, vascular disease, left ventricular (LV) ejection fraction <40% (vs. ≥50%), Lad ≥44 mm (vs. <36 mm), and creatinine clearance <50 mL/min were independently associated with AE incidences, but not with recurrences. CONCLUSIONS: This study disclosed different determinants of post-ablation recurrence and AEs. Female sex, persistent AF, and enlarged LAd were determinants of post-ablation recurrence, whereas an old age, comorbidities, and LV and renal dysfunction rather than post-ablation recurrence were AEs determinants. These findings will help determine ablation indications and post-ablation management.

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

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

High Plasma Levels of Fortilin in Patients with Coronary Artery Disease.

Excessive apoptosis is known to be a common feature of atherosclerotic lesions. Fortilin is recognized to have potent antiapoptotic properties. An increased fortilin expression was demonstrated in atherosclerotic lesions, and fortilin knockout mice developed less atherosclerosis. However, no study has reported blood fortilin levels in patients with coronary artery disease (CAD). We investigated plasma fortilin levels in 384 patients undergoing coronary angiography. CAD severity was evaluated as the numbers of stenotic vessels and segments. CAD was found in 208 patients (one-vessel (1VD), n = 86; two-vessel (2VD), n = 68; and three-vessel disease (3VD), n = 54). Plasma C-reactive protein (CRP) levels were higher in patients with CAD than without CAD (median 0.60 vs. 0.45 mg/L, p < 0.01). Notably, fortilin levels were higher in patients with CAD than without CAD (75.1 vs. 69.7 pg/mL, p < 0.02). A stepwise increase in fortilin was found according to the number of stenotic vessels: 69.7 in CAD(−), 71.1 in 1VD, 75.7 in 2VD, and 84.7 pg/mL in 3VD (p < 0.01). Fortilin levels also correlated with the number of stenotic segments (r = 0.16) and CRP levels (r = 0.24) (p < 0.01). In a multivariate analysis, fortilin levels were independently associated with 3VD. The odds ratio for 3VD was 1.93 (95%CI = 1.01−3.71) for a high fortilin level (>70.0 pg/mL). Thus, plasma fortilin levels in patients with CAD, especially those with 3VD, were found to be high and to be associated with the severity of CAD.

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

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

Association between Plasma Follistatin-like Protein 1 Levels and the Presence and Severity of Coronary Artery Disease.

Follistatin-like protein 1 (FSTL1) is a secreted glycoprotein known for its role in inflammation. However, plasma FSTL1 levels in patients with coronary artery disease (CAD) have not been fully elucidated. Thus, in this study, we investigated the plasma FSTL1 levels of 350 patients who underwent elective coronary angiography. The severity of CAD was represented as the numbers of > 50% stenotic vessels and segments and the severity score. CAD was detected in 196 patients, of whom 84 had 1-vessel disease (1-VD), 62 had 2-VD, and 50 had 3-VD. Plasma high-sensitivity C-reactive protein (hsCRP) levels were higher in patients with CAD than in those without CAD (median 0.56 versus 0.44 mg/L, P < 0.01). Notably, plasma FSTL1 levels were higher in patients with CAD than in those without CAD (median 4.05 versus 3.47 ng/mL, P < 0.02). A stepwise increase in FSTL1 levels was found depending on the number of > 50% stenotic vessels: 3.47 in CAD (-), 3.74 in 1-VD, 4.42 in 2-VD, and 4.65 ng/mL in 3-VD (P < 0.05). FSTL1 levels also correlated with the number of > 50% stenotic segments and the severity score (r = 0.14 and r = 0.15, respectively, P < 0.005) and hsCRP levels (r = 0.10, P < 0.05). In the multivariate analysis, FSTL1 levels were an independent factor associated with CAD. The odds ratio for CAD was 1.61 (95% CI = 1.01-2.58) for high FSTL1 level of > 3.6 ng/mL (P < 0.05). In conclusion, plasma FSTL1 levels in patients with CAD were found to be high and associated with the presence and severity of CAD, thus, suggesting that FSTL1 may play a role in the progression of coronary atherosclerosis.

Treatment strategies and subsequent changes in the patient-reported quality-of-life among elderly patients with atrial fibrillation.

BACKGROUND: Rhythm-control strategy, including catheter ablation (CA) application, constitutes an integral part of atrial fibrillation (AF) management. However, elderly patients are underrepresented in clinical trials, and reports on patient-reported outcome of various rhythm-control treatments remain limited. Therefore, we aimed to investigate the application of a rhythm-control strategy for elderly patients with AF. METHODS: Using a prospective, multicenter Japanese registry, we analyzed 733 patients with AF aged ≥70 years who completed the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire at baseline and 1-year visit. Improvement in patient-reported quality-of-life (QOL) was assessed according to their initial treatment strategy. RESULTS: A total of 321 patients (43.8%) were managed with rhythm-control strategy, of which 125 (17.1%) received treatment with antiarrhythmic drugs (AADs) alone and 196 (26.7%) underwent CA. Compared with the rate-control group, the rhythm-control group was younger and less likely to have comorbid conditions but had lower baseline AFEQT-overall summary (OS) scores (71.8 [standard deviation 20.3] vs. 80.0 [standard deviation 16.1]; P < .001). After the first year, AFEQT-OS scores improved regardless of treatment strategies (ie, rate- or rhythm-control). After adjusting for confounders, CA implementation and a lower baseline AFEQT score were associated with meaningful improvement in QOL (changes in AFEQT-OS score ≥5). QOL improvement among subgroups of rhythm-control patients with AADs alone was not clinically meaningful. CONCLUSIONS: In contemporary Japanese clinical practice, rhythm-control strategy is widely implemented in elderly patients with AF, and CA use is associated with improvement in QOL in carefully selected patients.

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

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

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

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

Identification of Left Atrial Appendage Thrombi in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation Using Intra-Cardiac Echocardiography and Cardiac Computed Tomography.

BACKGROUND: Intracardiac echocardiography (ICE) and cardiac computed tomography (CCT), in addition to standard transesophageal echocardiography (TEE), have been used to identify left atrial (LA) thrombi prior to ablation for atrial fibrillation (AF). The clinical advantages of this, however, remain unclear. This study therefore investigated the advantages of additional pre-procedural LA appendage (LAA) thrombus evaluation using ICE and the clinical value of CCT in persistent and long-standing persistent AF.Methods and Results:We analyzed data from 108 consecutive patients with persistent and long-standing persistent AF who were scheduled to undergo AF ablation. TEE was performed within 24 h prior to ablation. ICE was performed for 97 patients in whom a thrombus was not detected on TEE. CCT was performed in 95 patients. Thrombus or sludge was detected on TEE in 11 patients (10.3%), for whom ablation was cancelled. Four additional patients were diagnosed with LAA thrombus on ICE. When TEE and ICE were used as the reference for thrombus detection, the sensitivity, specificity, positive predictive value, and negative predictive value of CCT for identifying contrast defects in the LAA were 100%, 81.0%, 40.7%, and 100%, respectively. CONCLUSIONS: ICE combined with TEE increased the detection rate of LAA thrombi in patients with persistent and long-standing persistent AF. Moreover, CCT had high sensitivity and negative predictive value for LAA thrombus detection.

Visualization of the left atrial appendage by phased-array intracardiac echocardiography from the pulmonary artery in patients with atrial fibrillation.

AIMS: The left atrial appendage (LAA) represents the major source of cardiac thrombus formation in patients with atrial fibrillation (AF). Phased-array intracardiac echocardiography (ICE) has become available and frequently used during catheter ablation of AF. We attempted to study the feasibility of using ICE for the visualization and evaluation of the LAA from the pulmonary artery (PA) in patients with AF. METHODS AND RESULTS: Eighty patients with AF undergoing catheter ablation (70 males, 57.5 ± 9.1 years) were included. Transoesophageal echocardiography was performed on the prior day before the catheter ablation, and ICE was performed just before the transseptal puncture during the catheter ablation. The ICE catheter was advanced up into the PA from the femoral vein, where the LAA was clearly and entirely visualized by manipulating the ICE catheter. We compared the degree of spontaneous echo contrast, and the correlation was obtained between the ICE and TEE (κ = 0.534, P < 0.001). Furthermore, the LAA flow velocity (LAA emptying and filling velocities) measured by ICE had a good correlation to that measured by TEE (R = 0.872, P < 0.01 and R = 0.753, P < 0.01, respectively). No patients developed any complications. CONCLUSION: The utilization of ICE in the PA is feasible for the observation and evaluation of the LAA.

Brugada syndrome behind complete right bundle-branch block.

BACKGROUND: The characteristic ECG of Brugada syndrome (BS) can be masked by complete right bundle-branch block (CRBBB) and exposed by resolution of the block or pharmacological or pacing maneuvers. METHODS AND RESULTS: The study consisted of 11 patients who had BS and CRBBB. BS was diagnosed before the development of CRBBB, on the resolution of CRBBB, or from new characteristic ST-segment changes that could be attributable to BS. Structural heart diseases were excluded, and coronary spasm was excluded on the basis of a provocation test at catheterization. In 7 patients, BS was diagnosed before the development of CRBBB. BS was diagnosed when CRBBB resolved spontaneously (n=1) or by right ventricular pacing (n=3). The precipitating cause for the spontaneous resolution of CRBBB, however, was not apparent. On repeated ECGs, new additional upward-convex ST-segment elevation was found in V2 or V3 in 3 patients. In 2 patients, new ST-segment elevation was induced by class IC drugs. The QRS duration was more prolonged in patients with BS and CRBBB compared with age- and sex-matched controls: 170±13 versus 145±15 milliseconds in V1 and 144±19 versus 128±7 milliseconds in V5 (both P<0.0001). The amplitude of R in V1 was smaller [corrected] in the BS patients than in the control subjects (P=0.0323), but that of R' was similar (P=0.0560). CONCLUSIONS: BS can coexist behind CRBBB, and CRBBB can completely mask BS. BS might be demonstrated by relief of CRBBB or by spontaneous or drug-induced ST-segment elevation. The prevalence, mechanism, and clinical significance of a combination of CRBBB and BS are yet to be determined.

Electrophysiological properties of the superior vena cava and venoatrial junction in patients with atrial fibrillation: relevance to catheter ablation.

BACKGROUND: Although the superior vena cava (SVC) has been well known to be one of the important foci triggering atrial fibrillation (AF), its electrophysiological characteristics have received little research attention. The aim of this study was to investigate the electrophysiological properties of the SVC and venoatrial junction (VAJ). METHODS: Twenty-five consecutive AF patients without structural heart disease undergoing electrical SVC isolation were included in this study. After pulmonary vein isolation, a circular decapolar catheter and 2 multipolar catheters were emplaced in the VAJ, right atrial appendage (RAA), and SVC, respectively. Burst pacing and single extrastimulus were applied from the RAA and SVC. The atrial and caval potentials on the circular catheter in the VAJ were investigated. RESULTS: Intracaval conduction delay and various degrees of conduction block over the VAJ were observed with burst pacing from both the RAA and SVC. A single extrastimulus from the RAA and SVC with a basic cycle length of 600 milliseconds prolonged the conduction time via the VAJ by 81 ± 49.7 milliseconds and 61 ± 58.7 milliseconds, respectively. The atrial and caval electrograms at the VAJ, which were separated from each other by pacing applications, facilitated mapping of the earliest activation site at the VAJ. CONCLUSIONS: Intracaval conduction delay and decremental conduction property via the VAJ were demonstrated using pacing maneuvers. Pacing applications from the RAA or SVC can help distinguish the atrial and caval potentials and can facilitate mapping of the optimal ablation sites to isolate the SVC.

Effects of the selective KACh channel blocker NTC-801 on atrial fibrillation in a canine model of atrial tachypacing: comparison with class Ic and III drugs.

The present study examines the effects of NTC-801, a highly selective acetylcholine (ACh) receptor-activated potassium (KACh) channel blocker, on atrial fibrillation (AF) in a canine model with electrical remodeling. An experimental substrate for AF was created in dogs via left atrial (LA) tachypacing (400 bpm, 3-5 weeks). NTC-801, dofetilide, and flecainide were intravenously infused for 15 minutes, and the effects on AF inducibility, atrial effective refractory period (ERP), and atrial conduction velocity were examined. The effect of NTC-801 on AF termination was also evaluated. Atrial ERP was shortened and AF inducibility was increased after LA tachypacing. NTC-801 (0.3-3 µg·kg⁻¹·min⁻¹) prolonged atrial ERP irrespective of stimulation frequency and dose-dependently decreased AF inducibility. Dofetilide (5.3 µg·kg⁻¹·min⁻¹) and flecainide (0.13 mg·kg⁻¹·min⁻¹) did not significantly inhibit AF inducibility and minimally affected atrial ERP. Flecainide decreased atrial conduction velocity, whereas NTC-801 and dofetilide did not. NTC-801 (0.1 mg/kg) converted AF to normal sinus rhythm. In summary, NTC-801 exerted more effective antiarrhythmic effects than dofetilide and flecainide in a canine LA-tachypacing AF model. The antiarrhythmic activity of NTC-801 was probably due to prolonging atrial ERP independently of stimulation frequency. These results suggest that NTC-801 could prevent AF more effectively in the setting of atrial electrical remodeling.

Serum inflammation markers predicting successful initial catheter ablation for atrial fibrillation.

BACKGROUND: We investigated various serum inflammatory markers to predict ablation responders who have no atrial fibrillation (AF) relapse after the initial ablation. METHODS: Forty-four consecutive AF patients (age: 59 ± 8 years, paroxysmal: 31, CHADS2: 1.1 ± 1.1) who underwent an initial pulmonary vein isolation were investigated. Various serum inflammatory markers, such as adiponectin, ANP, BNP, 1CTP, F1+2, hs-CRP, IL-6, intact P1NP, MDA-LDL, MMP-2, TGF-ß, TIMP-2, and TNF-α, were evaluated prior to ablation. AF relapse was defined as AF documented in telemonitoring electrocardiograms twice a day during 9.7 ± 2.4 months of follow-up with three months of a blanking-period. RESULTS: A total of 29 patients (paroxysmal: 21) maintained sinus rhythm after the initial catheter ablation. These ablation responders had significantly lower MMP-2 (Sinus vs. Relapsed: 748 ± 132.7 vs. 841.2 ± 152.4 ng/mL, P=0.042) and TNF-α (1.1 ± 0.4 vs. 1.8 ± 1.7 pg/mL, P=0.046) levels prior to ablation. A BNP-adjusted Cox multivariate regression analysis revealed that the independent predictive factor for AF recurrence was high MMP-2 levels (>766 ng/mL) accompanied by high TNF-α levels (>1.2 pg/mL). CONCLUSIONS: The levels of MMP-2 and TNF-α might be useful for predicting initial AF catheter ablation responders.

Physician Estimates and Patient-Reported Health Status in Atrial Fibrillation.

Importance: A primary objective in managing atrial fibrillation (AF) is to optimize patients' health status, which can be done only if physicians accurately quantify the outcomes associated with AF in patients' lives. Objective: To explore physicians' estimation of the health status of patients with AF and its association with subsequent care and outcomes. Design, Setting, and Participants: A multicenter, prospective cohort study was conducted in 2 outpatient practices in Tokyo, Japan. Participants included patients with newly diagnosed AF or those referred for initial treatment of AF at outpatient practices and treating physicians from November 8, 2018, to April 1, 2020. Data analysis was performed from December 22, 2022, to July 7, 2023. Exposures: Participating patients completed the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire, a 20-item tool covering 4 domains with a 7-point Likert scale; 3 domains (symptoms, daily activities, and treatment concerns) were used in this study. Blinded to patients' responses, treating physicians answered a 3-item questionnaire quantifying each patient's AFEQT domain with a single item. Patients' mean Likert scale responses within each AFEQT domain were subtracted from the physicians' assessments so that higher scores (≥0.5 points) indicate physician underestimation, while lower scores (≤0.5 points) indicate physician overestimation of the health status of patients with AF. Main Outcomes and Measures: The independent association of physician-patient concordance with treatment escalation (alteration or initiation of antiarrhythmic drugs, cardioversion, or catheter ablation) and 1-year adjusted changes in AFEQT scores. Results: Among 330 patients (238 [72.1%] men; mean [SD] age, 67.9 [11.9] years; 163 [49.4%] with paroxysmal AF), physicians correctly estimated health status in 112 patients (33.9%), underestimated it in 42 patients (12.7%), and overestimated it in 176 patients (53.3%). Treatment escalation occurred in 63.6% of patients whose health status was correctly estimated, 47.6% of those whose health status was underestimated, and 66.3% of patients whose health status was overestimated. After multivariable adjustment, underestimation of health status was independently associated with less treatment escalation (adjusted odds ratio, 0.43; 95% CI, 0.20-0.90) and less frequent AFEQT overall summary score improvement at 1 year (underestimated, 2.5 [95% CI, -1.6 to 6.7] vs correctly and overestimated health status, 8.4 [95% CI, 7.0-9.9] points; P = .01). Conclusions and Relevance: In this cohort study, physician underestimation of the health status of patients with AF was common and associated with less aggressive treatment and less health status improvement at 1 year.

Ridge-related reentry: a variant of perimitral atrial tachycardia.

INTRODUCTION: The ridge between the left pulmonary veins (PV) and the left atrial appendage composes part of the lateral mitral isthmus (LMI). Following circumferential PV isolation and LMI linear ablation for the treatment of atrial fibrillation (AF), a critical pathway might develop over the ridge leading to a ridge-related reentry (RRR). METHODS AND RESULTS: Out of 61 patients who underwent circumferential PV isolation appended by LMI ablation, 5 patients developed RRR. The diagnosis of RRR was based on (1) macro-reentrant atrial tachycardia involving the septum, anterior and inferior wall of the left atrium; (2) slow conduction along the ridge; (3) wide-split double potentials in the ventricular aspect of the LMI were identified with the coronary sinus (CS) electrodes. RRR was investigated with electroanatomical mapping and entrainment mapping and catheter ablation was carried out in all patients. The mean cycle length (CL) of RRR was 312 ± 82 milliseconds and the PPIs at the left atrial septum, inferior and anterior wall during RRR were 10 ± 6, 12 ± 8, 9 ± 5 milliseconds longer than the RRR CL. The interval of the double potentials recorded in the CS electrodes crossing the LMI was 164 ± 38 milliseconds during RRR and the PPI on the LMI near the mitral annulus was 57 ± 10 milliseconds longer than the RRR CL. Catheter ablation was performed anatomically by targeting the ridge and successfully terminated RRR. CONCLUSION: After circumferential PV isolation and ablation for LMI in patients with AF, RRR can develop by utilizing the surviving myocardial tissue of the ridge as a critical pathway.

Three-dimensional imaging and mapping of the right and left phrenic nerves: relevance to interventional cardiovascular therapy.

AIMS: Phrenic nerves (PNs) can be damaged during interventional cardiovascular therapy because of the nerves' proximity to the heart. This study aimed to analyse the anatomy of the PN by performing three-dimensional (3-D) imaging and pace mapping. METHODS AND RESULTS: Forty consecutive patients with atrial fibrillation referred for catheter ablation were enrolled in this study and underwent preoperative cardiovascular computed tomography (CT). In 10 patients with sinus rhythm during tomography, 3-D images of the right and left pericardiophrenic bundles (PBs), consisting of the ipsilateral PN and accompanying vessels, were reconstructed from the CT data. During the electrophysiological study, PN pace mapping was performed from both atria. The course of the PBs generated by CT imaging and the PN pace map generated by the 3-D mapping system were compared. By electrical pacing, the PNs were captured in 40 individuals (100%) from the superior vena cava and the right atrium, and in 17 patients (43%) from the left atrial appendage. Clear 3-D images of PBs were reconstructed in all cases in which CT-reconstruction was performed. The distance between the locations of the right PB generated by CT imaging and those of the right PN-capture sites in the right-sided heart on the mapping system was 8.7 ± 5.8 mm. CONCLUSIONS: The 3-D routes of the bilateral PNs passing near the heart were verified by pace mapping. The preoperatively reconstructed 3-D course of the PB succeeded in locating the PN, which may facilitate the comprehension of PN anatomy to avoid its injury during interventional cardiovascular therapy.