Novel dual-reference approach facilitates the activation mapping and catheter ablation of premature atrial complexes with non-pulmonary vein and non-superior vena cava origins.

AIMS: Activation mapping of premature atrial complexes (PACs) proves challenging due to interference by mechanical bumping and non-targeted ectopies. This study aims to compare the mapping efficacy, instant success, and long-term recurrence of catheter ablation for PACs with non-pulmonary vein (PV) and non-superior vena cava (SVC) origins between the novel dual-reference approach (DRA) and the routine single-reference approach (SRA) of mapping. METHODS AND RESULTS: Patients with symptomatic, drug-refractory PACs, or frequent residual PACs after atrial tachyarrhythmia ablation were enrolled. During activation mapping, the coronary sinus (CS) catheter was used as the only timing reference in the SRA group. In the DRA group, another catheter, which was spatially separated from the CS catheter, was used as the second reference. The timing difference between the two references was used to discriminate the targeted PACs from the uninterested rhythms. Procedural parameters and long-term recurrence were compared. A total of 188 patients (109 in SRA and 79 in DRA) were enrolled. The baseline characteristics were similar. Compared with the SRA group, the DRA group had less repeated mapping (1.2 ± 0.4 vs. 1.4 ± 0.5, P = 0.004), shorter mapping (15 ± 6 vs. 23 ± 7 min, P < 0.001) and procedural time (119 ± 28 vs. 132 ± 22 min, P = 0.001), similar procedural complication rates (3.6 vs. 3.8%, P > 0.999), higher instant success (96.2 vs. 87.2%, P = 0.039), and lower recurrence rate (15.2 vs. 29.3%, hazard ratio 1.943, P = 0.033) during a 24-month follow-up. CONCLUSION: As a novel strategy, the DRA shortens the procedural time and improves both instant and long-term success of PAC ablation, serving as a promising approach in mapping PACs with non-PV and non-SVC origins.

Value of detecting peri-device leak and incomplete endothelialization by cardiac CT angiography in atrial fibrillation patients post Watchman LAAC combined with radiofrequency ablation.

OBJECTIVES: To explore the value of detecting the peri-device leak (PDL) and device endothelialization after left atrial appendage closure (LAAC) by cardiac computed tomography (CT) in patients with atrial fibrillation (AF), who underwent Watchman LAAC combined with radiofrequency ablation of atrial fibrillation (AFCA). METHODS: Patients with symptomatic drug-refractory atrial fibrillation at high risk of stroke (CHA2 DS2 -VASc Score ≥ 2), who underwent Watchman LAAC combined with AFCA in our center from March 2017 to December 2018 were enrolled. Maximum diameter of LAA orifice was determined by preoperative CCTA. A standardized view of Watchman device was obtained by postoperative CCTA multiplannar reconstruction to evaluate the PDL and device endothelialization. RESULTS: Approximately 84 patients post successful LAAC and AFCA were enrolled in this study. The satisfactory LAA occlusion rate was 100%. There was no death, bleeding, stroke, and device-related thrombus (DRT) events. At 6-month postprocedure, CCTA images evidenced complete endothelialization in 44 patients (no contrast enhancement in LAA); contrast enhancement in LAA and visible PDL in 33 patients; contrast enhancement in LAA but without PDL in seven patients (incomplete device endothelialization). Maximum diameter of LAA orifice could independently predict the occurrence of PDL (odds ratio, 1.31; 95% confidence interval, 1.11-1.55; p = .002), sensitivity was 69.7% and specificity was 80.4% with the cutoff value of maximum diameter of LAA orifice more than 28.2 mm on predicting PDL. CONCLUSIONS: CCTA is feasible to evaluate PDL and device endothelialization after LAAC. The maximum diameter of LAA orifice derived from CT can independently predict the occurrence of post-LAAC PDL.

Utility of Circadian Variability Patterns in Differentiating Origins of Premature Ventricular Complexes.

BACKGROUND: Premature ventricular complexes (PVCs) exhibit circadian fluctuation. We determine if PVCs of different origin exhibit specific circadian patterns. METHODS: We analyzed Holter recordings from patients with monomorphic PVCs who underwent catheter ablation. PVC circadian patterns were classified as fast-heart rate- (HR-) dependent (F-PVC), slow-HR-dependent (S-PVC), or HR-independent (I-PVC). PVC origins were determined intraprocedurally. RESULTS: In a retrospective cohort of 407 patients, F-PVC and S-PVC typically exhibited diurnal and nocturnal predominance, respectively. Despite decreased circadian fluctuation, I-PVC generally had heavier nocturnal than diurnal burden. PVCs of left anterior fascicle origin were predominantly S-PVC, while those of posterior hemibranch origin were mostly F-PVC. PVCs originating from the aortic sinus of Valsalva (ASV) were predominantly I-PVC, while most PVCs arising from the left ventricular outflow tract (LVOT) were F-PVC. Using a diurnal/nocturnal PVC burden ratio of 0.92 as the cutoff value to distinguish LVOT from ASV origin achieved 97% sensitivity and, as further verification, an accuracy of 89% (16/18) in a prospective cohort of patients with PVCs originating from either ASV or LVOT. In contrast, PVCs originating from right ventricles, such as right ventricular outflow tract, did not show distinct circadian patterns. CONCLUSIONS: The circadian patterns exhibit origin specificity for PVCs arising from left ventricles. An analysis of Holter monitoring provides useful information on PVC localization in ablation procedure planning.

Combined Therapy of Catheter Ablation and Left Atrial Appendage Closure for Patients with Atrial Fibrillation: A Case-Control Study.

AIM: The feasibility and safety of performing the combined procedure of catheter ablation (CA) and left atrial appendage closure (LAAC) for atrial fibrillation (AF) have been reported by observational studies without controls. The aim of this study was to compare the procedural and long-term outcomes of combined procedures with isolated CA or LAAC. METHODS AND RESULTS: This study included patients who underwent combined CA and LAAC (combined group), CA alone (CA-only group), or LAAC alone (LAAC-only group). Propensity score matching was used to select controls from the CA-only and LAAC-only groups. Each group contained 76 subjects. The procedures were successfully performed in all the patients. Procedure-related complications of the combined group included one pericardial effusion and two groin haematomas, which did not differ significantly with those of the CA-only group (3.9% vs. 2.6%, P=0.650) or the LAAC-only group (3.9% vs. 2.6%, P=0.650), respectively. The AF-free rate of the combined group was comparable with that of the CA-only group after a mean of 2 years follow-up (67.1% vs. 69.7%, P=0.727). Compared with the LAAC-only group, the combined group achieved similar complete occlusion rate at implant (94.7% vs. 93.4%) and at 45 days (82.9% vs. 85.5%). At the end of follow-up, ischemic stroke and bleeding events of the combined group were low (3.9%) and were comparable with those of the CA-only group (5.3%) and the LAAC-only group (2.6%). CONCLUSIONS: The combination of AF-CA and LAAC is safe and efficacious compared with single procedures alone.

Permanent left bundle branch area pacing utilizing intracardiac echocardiogram.

BACKGROUND: Recently, left bundle branch area pacing (LBBAP) has been shown to be feasible. However, the right ventricular (RV) implantation site for LBBAP remains elusive. We believe that the RV implantation site should be located at the posteromedial basal septum, and in this paper, we propose a new method to help guide lead implantation. The aim of this study is to demonstrate the feasibility of the proposed method. METHODS: The RV implantation site was positioned by a combination of a nine-grid system on fluoroscopy and the use of intracardiac echocardiogram (ICE) and then verified by ICE. RESULTS: Fifteen patients were enrolled for LBBAP using our method. The acute success rate was 86.7% (13/15), which demonstrated that our method is useful for assisting with lead implantation. According to ICE, the distance between the implantation site and apex (the front) and the distance between the implantation site and tricuspid annulus (the back) were 44.9 ± 10.7 and 33.2 ± 10.4 mm, respectively, and the ratio of the front and the back was 1.57 ± 0.80. The distance between the implantation site and the front junction point of the left-right ventricle (the upper) and the distance between the implantation site and the back junction point (the lower) were 33.4 ± 10.6 and 24.5 ± 10.2 mm, respectively. The ratio of the upper to the lower was 1.76 ± 1.36. These results suggest that the implantation site was at the posteromedial basal septum. The width of the QRS duration increased from 110.4 ± 33.1 ms at baseline to 114.1 ± 16.1 ms post LBBAP (P > 0.05). The operation time was 133 ± 32.9 min. The time of X-ray fluoroscopy was 21.2 ± 5.9 min. The mean time for lead positioning during LBBAP was 33.8 ± 16.6 min. During a follow-up of 3 months, the LBB capture threshold remained stable in 12 patients, except for one patient who had an increase in the LBB capture threshold to 3.0 v/0.4 ms. CONCLUSIONS: Our preliminary results indicate that the posteromedial basal septum could be seen as the implantation site for LBBAP. As a technique for LBBAP, ICE is a useful method for assisting with lead implantation. It is feasible and safe to use a nine-grid system combined with ICE for LBBAP.

Catheter ablation of ventricular arrhythmias originating from the para-Hisian region with reversed C-curve technique.

AIMS: Ventricular arrhythmias (VAs) originating from the para-Hisian region represent a challenging location. The long-term success rate of catheter ablation above the septal leaflet of the tricuspid valve is not ideal. This study aimed to investigate the safety and efficacy of catheter ablation for para-Hisian VAs via a direct approach under the septal valve with reversed C-curve technique. METHODS AND RESULTS: Twenty-five consecutive patients with para-Hisian VAs were included. Systematic mapping was performed in the right ventricle septum, including both the regions above and under the septal valve. Radiofrequency (RF) ablation was preferentially performed under the valve with reversed C-curve technique in all patients. If the ablation failed under the valve, it was then performed above the valve and even in aortic sinus cusps. The earliest ventricular activation preceding surface QRS (V-QRS) under the valve was significantly larger than that above the valve (34.8 ± 5.3 vs 27.8 ± 5.7 ms, P < .01). RF ablation under the valve with reversed C-curve technique achieved acute success in 22 of 25 (88%) patients. Junctional rhythm developed during ablation in 3 of 25 (12%) patients and no atrioventricular block occurred. In the remaining three patients, RF application above the valve failed to eliminate the VAs and one of them achieved successful ablation in the right coronary cusp. During a mean follow-up of 17.8 ± 9.4 months, no patients presented with VAs recurrence and no postprocedure complications occurred. CONCLUSIONS: Catheter ablation under the valve with reversed C-curve technique shows to be effective and safe for para-Hisian VAs.

Determinants of postoperative left atrial structural reverse remodeling in patients undergoing combined catheter ablation of atrial fibrillation and left atrial appendage closure procedure.

INTRODUCTION: Catheter ablation of atrial fibrillation (AFCA) and left atrial appendage closure (LAAC) exert opposite effects on left atrial (LA) size. We aim to observe the net impact of combined AFCA and LAAC strategy on LA size and explore those factors which might affect the postprocedure LA structural remodeling. METHODS: A total of 53 patients, who underwent combined AFCA and Watchman LAAC in our center from March to December 2017, were enrolled. Atrial fibrillation (AF) recurrence was monitored after the procedure. Left atrial volume (LAV) and left atrial appendage volume (LAAV) were measured by Mimics based on dual-source computed tomography images. RESULTS: At 6 months, sinus rhythm (SR) was maintained in 79.2% patients. LAV was significantly reduced (130.2 ± 36.3 mL to 107.1 ± 30.0 ml; P < .001) in SR maintenance group, but not in AF recurrence group (138.8 ± 39.3 mL to 137.9 ± 36.9 mL; P = .671). In SR group, preoperative LAAV/LAV ratio (B = -0.894; P = .015), NT-proBNP (B = 0.005; P = .019) and left ventricular ejection fraction (LVEF) (B = -0.778; P < .001) could interactively affect the extent of postoperative LA structural reverse remodeling, among which LAAV/LAV ratio could independently predict the significance of reverse remodeling (≥15% reduction in LAV) (OR, 0.56; 95% CI, 0.34-0.90; P = .018). A preoperative LAAV/LAV ratio less than 7.1% is indicative of significant LA structural reverse remodeling in this patient cohort. CONCLUSIONS: LA structural reverse remodeling could be evidenced in patients with maintained SR following combined AFCA and LAAC. Smaller LAAV/LAV ratio, higher NT-proBNP or lower LVEF at baseline are associated with more significant LA structural reverse remodeling, while LAAV/LAV ratio can predict the significance of the process after one-stop treatment.

Feasibility and Safety of Left Atrial Appendage Closure Using the LAmbre Device in Patients with Nonvalvular Atrial Fibrillation with or Without Prior Catheter Ablation.

Left atrial appendage (LAA) closure (LAAC) has emerged as an alternative therapeutic approach to medical therapy for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). However, complex LAA anatomy may preclude its use. LAmbre is a new, self-expanding LAA occluder, and is highly adaptable to different LAA morphologies. We explored the feasibility, safety, and efficacy of LAAC using LAmbre device in NVAF patients with or without prior catheter ablation (CA). LAAC using LAmbre device was applied in NVAF patients with (group C) or without (group N) prior CA. Transesophageal echocardiography (TEE) was performed at 3, and 12 months post-LAAC. Among 17 LAAC patients (group C, 6 & group N, 11), 4 cases were implanted with special type devices, 5 were implanted with large devices. Besides one case of cardiac tamponade (N group), there were two minor peri-procedural complications only. Successful sealing of the LAA was documented in all the patients (100%) by TEE both post LAAC and at 3 months. At 3 months, no residual flow was achieved in 11 patients (64.7%); six patients (35.3%) had residual flow < 5 mm. There was no device dislocation or leakage during the mean of 30 months follow up. At 545 days after LAAC, one patient in group C experienced sudden death. Baseline, peri-procedural, and follow-up characteristics were similar between two groups (P > 0.05). LAAC with LAmbre device, subsequent to prior CA for AF, can be performed successfully and safely. The design and distinguishing features of this device could be of help in patients with complex anatomy of LAA.

Clinical Features of Post Cardiac Injury Syndrome Following Catheter Ablation of Arrhythmias: Systematic Review and Additional Cases.

BACKGROUND: Post cardiac injury syndrome (PCIS) is a troublesome but not uncommon complication following catheter ablation of arrhythmias. We aimed to study the clinical features of ablation-associated PCIS. METHODS: For this purpose, we conducted a computerised literature search that identified 19 published cases, and we additionally included another two new cases from our centres. Twenty-one (21) cases of PCIS following ablation were analysed. RESULTS: Among the 21 cases, PCIS most commonly occurred after atrial flutter/fibrillation (AFL/AF) ablation (71.4%), followed by atrioventricular re-entrant tachycardia (AVRT) ablation (9.5%), atrioventricular node (AVN) ablation (9.5%), atrioventricular nodal re-entrant tachycardia (AVNRT) ablation (4.8%) and ventricular tachycardia (VT) ablation (4.8%). Thirty-eight (38) per cent of PCIS was suggested to be secondary to cardiac perforation. Specific symptoms or features include pleuritic chest pain (76.2%), fever (76.2%), elevated markers of inflammation (76.2%), pericardial effusion (90.5%), pleural effusion (71.4%) and pulmonary infiltrates (28.6%). Interestingly, all the six cases with pulmonary infiltrates were following AFL/AF ablation (6/15, 40%). Serious clinical manifestations include cardiac tamponade, massive pleural effusion with hypoalbuminaemia and hyponatraemia, and massive pulmonary infiltrates with hypoxaemia. Notably, empiric antibiotic therapy was used in seven cases including five with pulmonary infiltrates but failed to work. No mortality occurred during a mean follow-up of 4.1±5.3 (1 to 19) months. CONCLUSIONS: Catheter ablation of AFL/AF was most commonly involved in ablation-associated PCIS. Pulmonary infiltrate is an important feature of PCIS following AFL/AF ablation and may be misdiagnosed as pneumonia. Although PCIS is troublesome and even dangerous, it does carry a benign prognosis.

Semaphorin 3a transfection into the left stellate ganglion reduces susceptibility to ventricular arrhythmias after myocardial infarction in rats.

AIMS: Myocardial infarction (MI) induces neural remodelling of the left stellate ganglion (LSG), which may contribute to ischaemia-induced arrhythmias. The neural chemorepellent Semaphorin 3a (Sema3a) has been identified as a negative regulator of sympathetic innervation in the LSG and heart. We previously reported that overexpression of Sema3a in the border zone could reduce the arrhythmogenic effects of cardiac sympathetic hyperinnervation post-MI. This study investigated whether Sema3a overexpression within the LSG confers an antiarrhythmic effect after MI through decreasing extra- and intra-cardiac neural remodelling. METHODS AND RESULTS: Sprague-Dawley rats were subjected to MI, and randomly allocated to intra-LSG microinjection of either phosphate-buffered saline (PBS), adenovirus encoding green fluorescent protein (AdGFP), or adenovirus encoding Sema3a (AdSema3a). Sham-operated rats served as controls. Two weeks after infarction, MI-induced nerve sprouting and sympathetic hyperinnervation in the LSG and myocardium were significantly attenuated by intra-LSG injection with AdSema3a, as assessed by immunohistochemistry and western blot analysis of growth-associated protein 43 and tyrosine hydroxylase. This was also confirmed by sympathetic nerve function changes assessed by cardiac norepinephrine content. Additionally, intra-LSG injection with AdSema3a alleviated MI-induced accumulation of dephosphorylated connexin 43 in the infarct border zone. Furthermore, Sema3a overexpression in the LSG reduced the incidence of inducible ventricular tachyarrhythmia by programmed electrical stimulation post-MI, and arrhythmia scores were significantly lower in the AdSema3a group than in the PBS and AdGFP groups. CONCLUSION: Semaphorin 3a overexpression in the LSG ameliorates the inducibility of ventricular arrhythmias after MI, mainly through attenuation of neural remodelling within the cardiac-neuraxis.

Pharmacogenetics-based warfarin dosing algorithm decreases time to stable anticoagulation and the risk of major hemorrhage: an updated meta-analysis of randomized controlled trials.

Warfarin is yet the most widely used oral anticoagulant for thromboembolic diseases, despite the recently emerged novel anticoagulants. However, difficulty in maintaining stable dose within the therapeutic range and subsequent serious adverse effects markedly limited its use in clinical practice. Pharmacogenetics-based warfarin dosing algorithm is a recently emerged strategy to predict the initial and maintaining dose of warfarin. However, whether this algorithm is superior over conventional clinically guided dosing algorithm remains controversial. We made a comparison of pharmacogenetics-based versus clinically guided dosing algorithm by an updated meta-analysis. We searched OVID MEDLINE, EMBASE, and the Cochrane Library for relevant citations. The primary outcome was the percentage of time in therapeutic range. The secondary outcomes were time to stable therapeutic dose and the risks of adverse events including all-cause mortality, thromboembolic events, total bleedings, and major bleedings. Eleven randomized controlled trials with 2639 participants were included. Our pooled estimates indicated that pharmacogenetics-based dosing algorithm did not improve percentage of time in therapeutic range [weighted mean difference, 4.26; 95% confidence interval (CI), -0.50 to 9.01; P = 0.08], but it significantly shortened the time to stable therapeutic dose (weighted mean difference, -8.67; 95% CI, -11.86 to -5.49; P < 0.00001). Additionally, pharmacogenetics-based algorithm significantly reduced the risk of major bleedings (odds ratio, 0.48; 95% CI, 0.23 to 0.98; P = 0.04), but it did not reduce the risks of all-cause mortality, total bleedings, or thromboembolic events. Our results suggest that pharmacogenetics-based warfarin dosing algorithm significantly improves the efficiency of International Normalized Ratio correction and reduces the risk of major hemorrhage.

Real world risk of discontinuing oral anticoagulation after successful catheter ablation for atrial fibrillation.

Background: Many patients with atrial fibrillation (AF) discontinued oral anticoagulation (OAC) therapy after successful catheter ablation. We aimed to determine the real-world risks and consequences of discontinuing OAC use after catheter ablation for AF. Methods: Patients who underwent successful catheter ablation for AF from January 2004 to December 2020 were divided into continued long-term OAC (On-OAC, n = 1062) and discontinued (Off-OAC, n = 1055) groups. The long-term outcomes including thromboembolic events, major bleeding, all-cause mortality and major adverse cardiovascular events (MACE), were compared between the two groups. Results: The CHA2DS2-VASc score was 3.44 ± 1.12. After a mean follow-up of 37.09 months, thromboembolism risk was higher and major bleeding risk was lower in the Off-OAC than in the On-OAC group (Both log-rank P < 0.001). CHA2DS2-VASc score-stratified subgroup analysis showed similar cumulative event rates between the two groups in men and women with scores of 2 and 3 (intermediate risk for stroke), respectively, (P > 0.05), except for a higher major bleeding rate in the On-OAC group (P = 0.002). Patients at high risk for stroke (men and women with scores ≥3 and ≥ 4) had better non-thromboembolic and non-MACE results (Both log-rank P < 0.05). Conclusion: Men with a CHA2DS2-VASc score of 2 and women with a score of 3 had a relatively low incidence of stroke events after successful catheter ablation for AF and may be safe for anticoagulation cessation. Greater benefits from long-term OAC were observed in men with CHA2DS2-VASc score ≥3 and women with score ≥4.

Prognostic Impact of Left Atrial Appendage Patency After Device Closure.

BACKGROUND: The prognostic impact of left atrial appendage (LAA) patency, including those with and without visible peri-device leak (PDL), post-LAA closure in patients with atrial fibrillation, remains elusive. METHODS: Patients with atrial fibrillation implanted with the WATCHMAN 2.5 device were prospectively enrolled. The device surveillance by cardiac computed tomography angiography was performed at 3 months post-procedure. Adverse events, including stroke/transient ischemic attack (TIA), major bleeding, cardiovascular death, all-cause death, and the combined major adverse events (MAEs), were compared between patients with complete closure and LAA patency. RESULTS: Among 519 patients with cardiac computed tomography angiography surveillance at 3 months post-LAA closure, 271 (52.2%) showed complete closure, and LAA patency was detected in 248 (47.8%) patients, including 196 (37.8%) with visible PDL and 52 (10.0%) without visible PDL. During a median of 1193 (787-1543) days follow-up, the presence of LAA patency was associated with increased risks of stroke/TIA (adjusted hazard ratio for baseline differences, 3.22 [95% CI, 1.17-8.83]; P=0.023) and MAEs (adjusted hazard ratio, 1.12 [95% CI, 1.06-1.17]; P=0.003). Specifically, LAA patency with visible PDL was associated with increased risks of stroke/TIA (hazard ratio, 3.66 [95% CI, 1.29-10.42]; P=0.015) and MAEs (hazard ratio, 3.71 [95% CI, 1.71-8.07]; P=0.001), although LAA patency without visible PDL showed higher risks of MAEs (hazard ratio, 3.59 [95% CI, 1.28-10.09]; P=0.015). Incidences of stroke/TIA (2.8% versus 3.0% versus 6.7% versus 22.2%; P=0.010), cardiovascular death (0.9% versus 0% versus 1.7% versus 11.1%; P=0.005), and MAEs (4.6% versus 9.0% versus 11.7% versus 22.2%; P=0.017) increased with larger PDL (0, >0 to ≤3, >3 to ≤5, or >5 mm). Older age and discontinuing antiplatelet therapy at 6 months were independent predictors of stroke/TIA and MAEs in patients with LAA patency. CONCLUSIONS: LAA patency detected by cardiac computed tomography angiography at 3 months post-LAA closure is associated with unfavorable prognosis in patients with atrial fibrillation implanted with WATCHMAN 2.5 device. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03788941.

Overexpression of Sema3a in myocardial infarction border zone decreases vulnerability of ventricular tachycardia post-myocardial infarction in rats.

The expression of the chemorepellent Sema3a is inversely related to sympathetic innervation. We investigated whether overexpression of Sema3a in the myocardial infarction (MI) border zone could attenuate sympathetic hyper-innervation and decrease the vulnerability to malignant ventricular tachyarrhythmia (VT) in rats. Survived MI rats were randomized to phosphate buffered saline (PBS, n = 12); mock lentivirus (MLV, n = 13) and lentivirus-mediated overexpression of Sema3a (SLV, n = 13) groups. Sham-operated rats served as control group (CON, n = 20). Cardiac function and electrophysiological study (PES) were performed at 1 week later. Blood and tissue samples were collected for histological analysis, epinephrine (EPI), growth-associated factor 43 (GAP43) and tyrosine hydroxylase (TH) measurements. QTc intervals were significantly shorter in SLV group than in PBS and MLV groups (168.6 ± 7.8 vs. 178.1 ± 9.5 and 180.9 ± 8.2 ms, all P < 0.01). Inducibility of VT by PES was significantly lower in the SLV group [30.8% (4/13)] than in PBS [66.7% (8/12)] and MLV [61.5% (8/13)] groups (P < 0.05). mRNA and protein expressions of Sema3a were significantly higher and the protein expression of GAP43 and TH was significantly lower at 7 days after transduction in SLV group compared with PBS, MLV and CON groups. Myocardial EPI in the border zone was also significantly lower in SLV group than in PBS and MLV group (8.73 ± 1.30 vs. 11.94 ± 1.71 and 12.24 ± 1.54 µg/g protein, P < 0.001). Overexpression of Sema3a in MI border zone could reduce the inducibility of ventricular arrhythmias by reducing sympathetic hyper-reinnervation after infarction.

Resveratrol protects rabbit ventricular myocytes against oxidative stress-induced arrhythmogenic activity and Ca2+ overload.

AIM: To investigate whether resveratrol suppressed oxidative stress-induced arrhythmogenic activity and Ca(2+) overload in ventricular myocytes and to explore the underlying mechanisms. METHODS: Hydrogen peroxide (H2O2, 200 µmol/L)) was used to induce oxidative stress in rabbit ventricular myocytes. Cell shortening and calcium transients were simultaneously recorded to detect arrhythmogenic activity and to measure intracellular Ca(2+) ([Ca(2+)]i). Ca(2+)/calmodulin-dependent protein kinases II (CaMKII) activity was measured using a CaMKII kit or Western blotting analysis. Voltage-activated Na(+) and Ca(2+) currents were examined using whole-cell recording in myocytes. RESULTS: H2O2 markedly prolonged Ca(2+) transient duration (CaTD), and induced early afterdepolarization (EAD)-like and delayed afterdepolarization (DAD)-like arrhythmogenic activity in myocytes paced at 0.16 Hz or 0.5 Hz. Application of resveratrol (30 or 50 µmol/L) dose-dependently suppressed H2O2-induced EAD-like arrhythmogenic activity and attenuated CaTD prolongation. Co-treatment with resveratrol (50 µmol/L) effectively prevented both EAD-like and DAD-like arrhythmogenic activity induced by H2O2. In addition, resveratrol markedly blunted H2O2-induced diastolic [Ca(2+)]i accumulation and prevented the myocytes from developing hypercontracture. In whole-cell recording studies, H2O2 significantly enhanced the late Na(+) current (I(Na,L)) and L-type Ca(2+) current (I(Ca,L)) in myocytes, which were dramatically suppressed or prevented by resveratrol. Furthermore, H2O2-induced ROS production and CaMKII activation were significantly prevented by resveratrol. CONCLUSION: Resveratrol protects ventricular myocytes against oxidative stress-induced arrhythmogenic activity and Ca(2+) overload through inhibition of I(Na,L)/I(Ca,L), reduction of ROS generation, and prevention of CaMKII activation.

Sex Differences in the Combined Ablation and Left Atrial Appendage Closure: Results From LAACablation Registry.

Background: More than 40% of left atrial appendage closure (LAAC) procedures were combined with atrial fibrillation (AF) ablation in China. Objectives: This study aimed to assess the sex differences in the combined radiofrequency catheter ablation and LAAC procedures. Methods: Data from the LAACablation (Left Atrial Appendage Closure in Combination With Catheter Ablation) registry, which enrolled AF patients who underwent the combined procedure between 2018 and 2021, were analyzed. Procedural complications, long-term outcomes, and quality of life (QoL) were compared between sexes. Results: Of 931 patients, 402 (43.2%) were women. Compared with men, women were older (age 71.3 ± 7.4 years vs 68.7 ± 8.1 years; P < 0.001), presented more often with paroxysmal AF (52.5% vs 42.7%; P < 0.003), and had higher CHA2DS2-VASc scores (4.1 ± 1.5 vs 3.1 ± 1.5; P < 0.001), but received less often linear ablation and had shorter total procedural times and radiofrequency catheter ablation times. Women had similar rates of total and major procedural complications but presented with a higher incidence of minor complications than men (3.7% vs 1.3%; P = 0.027). Follow-up over 1,812 patient-years revealed similar adverse events between women and men, including all-cause death (HR: 0.89; 95% CI: 0.43-1.85; P = 0.754), thromboembolic events (HR: 1.17; 95% CI: 0.54-2.52; P = 0.697), major bleeding (HR: 0.96; 95% CI: 0.38-2.44; P = 0.935), and their composite (HR: 0.85; 95% CI: 0.56-1.28; P = 0.434). The recurrence rates of atrial tachyarrhythmia were also comparable between sexes presenting either paroxysmal or persistent AF. Women were seen with greater QoL impairment at baseline, but the sex gap narrowed at 1-year follow-up. Conclusions: In AF patients who underwent the combined procedure, women had similar procedural safety and long-term efficacy to men and presented greater QoL improvement. (Left Atrial Appendage Closure in Combination With Catheter Ablation [LAACablation]; NCT03788941).

Combined Radiofrequency Ablation and Left Atrial Appendage Closure in Atrial Fibrillation and Systolic Heart Failure.

BACKGROUND: Managing patients with atrial fibrillation (AF) and comorbid heart failure (HF) with reduced (HFrEF) or mildly reduced ejection fraction (HFmrEF) is of clinical importance but a great challenge. This study aimed to evaluate the clinical benefit of the combined radiofrequency catheter ablation (RFCA) and left atrial appendage closure (LAAC) procedure in AF patients complicated with systolic HF. METHODS: AF patients with HFrEF or HFmrEF who underwent the combined RFCA and LAAC procedure were prospectively enrolled in the LAACablation registry. The procedural complications and long-term outcomes were evaluated. Another cohort of AF patients with systolic HF who did not undergo either RFCA or LAAC were used for prognosis comparison. RESULTS: Among 802 AF patients who underwent the combined procedure, 65 patients were comorbid with systolic HF (25 with HFrEF and 40 with HFmrEF). The overall procedural complication rate was 9.2%, which was mainly attributed to acute decompensated HF (6.2%). Accompanied with markedly reduced AF burden (from median [25th, 75th percentile]: 100 [100, 100] to 0 [0, 1.2]%, p < 0.001), upward trajectories of cardiac function were observed in 51 (78.4%) patients, showing improvement in New York Heart Classification (p < 0.01), natriuretic peptide levels (from 1492 [809, 3259] to 413 [163, 880] pg/mL, p < 0.001) and left ventricular EF (from 42.6 ± 5.3 to 53.8 ± 8.2%, p < 0.001). During the 27-month follow-up period, death, thromboembolism, major bleeding, and HF rehospitalization were observed in three, one, one, and four patients, respectively. The observed event rates showed a significant reduction compared with the non-procedure AF-HF cohort (n = 138; for composite endpoint: hazard ratio: 2.509, 95% confidence interval: 1.415-4.449, p = 0.002) and with the respective rates predicted by risk scores. CONCLUSIONS: Combining RFCA and LAAC achieves acceptable safety and credible long-term efficacy in AF patients with systolic HF. Further randomized studies are warranted in a larger patient cohort.