NR4A3 prevents diabetes induced atrial cardiomyopathy by maintaining mitochondrial energy metabolism and reducing oxidative stress.

BACKGROUND: Atrial cardiomyopathy (ACM) is responsible for atrial fibrillation (AF) and thromboembolic events. Diabetes mellitus (DM) is an important risk factor for ACM. However, the potential mechanism between ACM and DM remains elusive. METHODS: Atrial tissue samples were obtained from patients diagnosed with AF or sinus rhythm (SR) to assess alterations in NR4A3 expression, and then two distinct animal models were generated by subjecting Nr4a3-/- mice and WT mice to a high-fat diet (HFD) and Streptozotocin (STZ), while db/db mice were administered AAV9-Nr4a3 or AAV9-ctrl. Subsequently, in vivo and in vitro experiments were conducted to assess the impact of NR4A3 on diabetes-induced atrial remodeling through electrophysiological, biological, and histological analyses. RNA sequencing (RNA-seq) and metabolomics analysis were employed to unravel the downstream mechanisms. FINDINGS: The expression of NR4A3 was significantly decreased in atrial tissues of both AF patients and diabetic mice compared to their respective control groups. NR4A3 deficiency exacerbated atrial hypertrophy and atrial fibrosis, and increased susceptibility to pacing-induced AF. Conversely, overexpression of NR4A3 alleviated atrial structural remodeling and reduced AF induction rate. Mechanistically, we confirmed that NR4A3 improves mitochondrial energy metabolism and reduces oxidative stress injury by preserving the transcriptional expression of Sdha, thereby exerting a protective influence on atrial remodeling induced by diabetes. INTERPRETATION: Our data confirm that NR4A3 plays a protective role in atrial remodeling caused by diabetes, so it may be a new target for treating ACM. FUNDING: This study was supported by the major research program of National Natural Science Foundation of China (NSFC) No: 82370316 (to Q-S. W.), No. 81974041 (to Y-P. W.), and No. 82270447 (to Y-P. W.) and Fundation of Shanghai Hospital Development Center (No. SHDC2022CRD044 to Q-S. W.).

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.

BRD4 as a therapeutic target for atrial fibrosis and atrial fibrillation.

OBJECTIVE: This study aimed to elucidate the molecular mechanisms by which BRD4 play a role in atrial fibrillation (AF). METHODS AND RESULTS: We used a discovery-driven approach to detect BRD4 expression in the atria of patients with AF and in various murine models of atrial fibrosis. We used a BRD4 inhibitor (JQ1) and atrial fibroblast (aFB)-specific BRD4-knockout mice to elucidate the role of BRD4 in AF. We further examined the underlying mechanisms using RNA-seq and ChIP-seq analyses in vitro, to identify key downstream targets of BRD4. We found that BRD4 expression is significantly increased in patients with AF, with accompanying atrial fibrosis and aFB differentiation. We showed that JQ1 treatment and shRNA-based molecular silencing of BRD4 blocked ANG-II-induced extracellular matrix production and cell-cycle progression in aFBs. BRD4-related RNA-seq and ChIP-seq analyses in aFBs demonstrated enrichment of a subset of promoters related to the expression of profibrotic and proliferation-related genes. The pharmacological inhibition of BRD4 in vivo or in aFB-specific BRD4-knockout in mice limited ANG-II-induced atrial fibrosis, atrial enlargement, and AF susceptibility. CONCLUSION: Our findings suggest that BRD4 plays a key role in pathological AF, at least partially by activating aFB proliferation and ECM synthesis. This study provides mechanistic insights into the development of BRD4 inhibitors as targeted antiarrhythmic therapies.

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.

Coptisine inhibits neointimal hyperplasia through attenuating Pak1/Pak2 signaling in vascular smooth muscle cells without retardation of re-endothelialization.

BACKGROUND AND AIMS: Vascular injury-induced endothelium-denudation and profound vascular smooth muscle cells (VSMCs) proliferation and dis-regulated apoptosis lead to post-angioplasty restenosis. Coptisine (CTS), an isoquinoline alkaloid, has multiple beneficial effects on the cardiovascular system. Recent studies identified it selectively inhibits VSMCs proliferation. However, its effects on neointimal hyperplasia, re-endothelialization, and the underlying mechanisms are still unclear. METHODS: Cell viability was assayed by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and cell counting kit-8 (CCK-8). Cell proliferation and apoptosis were measured by flow cytometry and immunofluorescence of Ki67 and TUNEL. Quantitative phosphoproteomics (QPP) was employed to screen CTS-responsive phosphor-sites in the key regulators of cell proliferation and apoptosis. Neointimal hyperplasia was induced by balloon injury of rat left carotid artery (LCA). Adenoviral gene transfer was conducted in both cultured cells and LCA. Re-endothelialization was evaluated by Evan's blue staining of LCA. RESULTS: 1) CTS had strong anti-proliferative and pro-apoptotic effects in cultured rat VSMCs, with the EC50 4∼10-folds lower than that in endothelial cells (ECs). 2) Rats administered with CTS, either locally to LCA's periadventitial space or orally, demonstrated a potently inhibited balloon injury-induced neointimal hyperplasia, but had no delaying effect on re-endothelialization. 3) The QPP results revealed that the phosphorylation levels of Pak1S144/S203, Pak2S20/S197, Erk1T202/Y204, Erk2T185/Y187, and BadS136 were significantly decreased in VSMCs by CTS. 4) Adenoviral expression of phosphomimetic mutants Pak1D144/D203/Pak2D20/D197 enhanced Pak1/2 activities, stimulated the downstream pErk1T202/Y204/pErk2T185/Y187/pErk3S189/pBadS136, attenuated CTS-mediated inhibition of VSMCs proliferation and promotion of apoptosis in vitro, and potentiated neointimal hyperplasia in vivo. 5) Adenoviral expression of phosphoresistant mutants Pak1A144/A203/Pak2A20/A197 inactivated Pak1/2 and totally simulated the inhibitory effects of CTS on platelet-derived growth factor (PDGF)-stimulated VSMCs proliferation and PDGF-inhibited apoptosis in vitro and neointimal hyperplasia in vivo. 6) LCA injury significantly enhanced the endogenous phosphorylation levels of all but pBadS136. CTS markedly attenuated all the enhanced levels. CONCLUSIONS: These results indicate that CTS is a promising medicine for prevention of post-angioplasty restenosis without adverse impact on re-endothelialization. CTS-directed suppression of pPak1S144/S203/pPak2S20/S197 and the subsequent effects on downstream pErk1T202/Y204/pErk2T185/Y187/pErk3S189 and pBadS136 underline its mechanisms of inhibition of VSMCs proliferation and stimulation of apoptosis. Therefore, the phosphor-sites of Pak1S144/S203/Pak2S20/S197 constitute a potential drug-screening target for fighting neointimal hyperplasia restenosis.

Incidence, impact and predictors of residual device patency after left atrial appendage closure with the LACbes device.

BACKGROUND: The residual device patency (RDP) after left atrial appendage closure (LAAC) with the LACbes device has not been specifically explored in atrial fibrillation (AF) patients. This study aims to explore the incidence, impact and predictors of RDP detected by cardiac computed tomography angiography (CCTA) post LAAC. METHODS: AF patients implanted with the LACbes device were prospectively enrolled. CCTA device surveillance was performed at 3 months post-procedure. Major adverse events (MAEs), including stroke/transient ischemic attack, major bleeding and all-cause death, were evaluated. RESULTS: Among 141 patients with CCTA surveillance, 56 (39.7%) showed no visible leak and 85 (60.3%) showed RDP. During the median follow-up of 443 [232, 706] days, the presence of RDP was not associated with an increased risk of MAEs (adjusted hazard ratio [HR]: 4.07, 95% confidence interval [CI]: 0.49-34.24, p = 0.196), while peri-device leak (PDL) at the lobe was associated with heightened risks of MAEs (adjusted HR: 6.85, 95% CI: 1.62-28.89, p = 0.009). In patients with PDL at the lobe, antiplatelet after 6 months (HR: 0.20, 95% CI: 0.05-0.91, p = 0.038) was independent protective predictor of MAEs. Besides, current smoking (odds ratio [OR]: 7.52, 95% CI: 2.68-21.08, p < 0.001) and maximum diameter of LAA orifice (OR: 1.16, 95% CI: 1.00-1.34, p = 0.048) were independent predictors of PDL at the lobe. CONCLUSIONS: Presence of PDL at the device lobe detected by CCTA at 3-month post LAAC with LACbes is associated with unfavorable prognosis in AF patients. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: 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.

Accuracy of the Injection-Based Occlusion Tool Utilizing Saline and Glucose Solution in Cryoballoon Ablation Guided by a Novel Dielectric Imaging System.

Introduction: The aim of this study is to assess the accuracy of the injection-based occlusion (IBO) tool utilizing saline and glucose solution in verifying pulmonary vein (PV) occlusion during cryoballoon ablation guided by a novel dielectric system (KODEX-EPD system). Methods: In this retrospective study, we enrolled 34 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent their initial cryoballoon ablation procedure guided by the KODEX-EPD system. PV occlusion was firstly assessed by the IBO tool utilizing saline or glucose solution and then verified by direct contrast angiography. Patients were divided into two groups according to the fluid used in the IBO tool: the Saline Group and the Glucose Group. Results: The overall procedure time and fluoroscopy time were comparable between the Saline Group and the Glucose Group (113.7 ± 18.3 vs. 108.4 ± 15.9 min; p = 0.375 and 10.1 ± 3.7 vs. 9.3 ± 3.5 min; p = 0.559). The IBO tool was utilized a total of 138 times in the Saline Group and 135 times in the Glucose Group. When assessing PV occlusion, the IBO tool using saline demonstrated a sensitivity of 92.6% and a specificity of 95.2% compared to angiography. Similarly, the IBO tool utilizing glucose solution showed a sensitivity of 93.2% and a specificity of 96.1%. Conclusions: The IBO tool utilizing non-contrast fluid, saline and glucose solution, demonstrates a high level of sensitivity and specificity in accurately predicting PV occlusion during cryoablation procedures. Both the saline and glucose solutions used in the IBO tool show promising results in effectively assessing PV occlusion.

Cancer and Atrial Fibrillation Comorbidities Among 25 Million Citizens in Shanghai, China: Medical Insurance Database Study.

BACKGROUND: With population aging, the prevalence of both cancer and atrial fibrillation (AF) have increased. However, there is scarce epidemiological data concerning the comorbid state of cancer and AF in low- and middle-income countries, including China. OBJECTIVE: We aimed to evaluate the site-, sex-, and age-specific profiles of cancer and AF comorbidities in Chinese populations. METHODS: Data from the Shanghai Municipal Health Commission database between 2015 and 2020 were screened, covering all medical records of Shanghai residents with medical insurance. Site-specific cancer profiles were evaluated for the population with AF relative to the age- and sex-adjusted population of residents without AF. The sex distribution and peak age of cancer diagnosis were also assessed. RESULTS: A total of 25,964,447 adult patients were screened. Among them, 22,185 patients presented cancers comorbid with AF (median 77, IQR 67-82 years of age; men: n=13,631, 61.44%), while 839,864 presented cancers without AF (median 67, IQR 57-72 years of age; men: n=419,020, 49.89%), thus yielding a higher cancer prevalence among residents with AF (8.27%) than among those without AF (6.05%; P<.001). In the population with AF, the most prevalent cancer type was lung cancer, followed by colorectal, male genital organ, stomach, breast, liver, bladder, thyroid, leukemia, and esophageal cancers. AF was associated with an average of nearly 1.4-fold (prevalence ratio [PR] 1.37, 95% CI 1.35-1.38) increased prevalence of cancer after adjusting for age and sex. For site-specific analyses, an increased prevalence of cancer in the population with AF was observed in 20 of 21 cancer sites. This increased prevalence was most prominent for nonsolid tumors, including multiple myeloma (PR 2.56, 95% CI 2.28-2.87), leukemia (PR 1.73, 95% CI 1.57-1.90), and non-Hodgkin lymphoma (PR 1.59, 95% CI 1.43-1.77); intrathoracic malignancies, including mediastinum (PR 2.34, 95% CI 1.89-2.90), lung (PR 1.64, 95% CI 1.59-1.69), and esophageal cancers (PR 1.41, 95% CI 1.28-1.56); bone and soft tissue neoplasms (PR 1.56, 95% CI 1.37-1.77); and kidney cancer (PR 1.53, 95% CI 1.36-1.72). Cancer prevalence in the population with AF relative to that in the population without AF was higher in men than in women in 14 of 18 cancer sites, and female predominance was only observed for thyroid cancer. The peak age of index cancer diagnosis was lower in the population with AF (age group: 70-74 years) than in that without AF (age group: 75-79 years), especially for specific cancer types, including thyroid, central nervous system, mediastinum, esophageal, bladder, and biliary cancers. CONCLUSIONS: Patients with AF are associated with increased prevalence, heightened male predominance, and younger peak age of cancer. Further studies are needed to determine whether early screening of specific cancers is cost-effective and beneficial for patients with AF.

Higher Sodium Channel Excitability in Cardiac Purkinje Fibers: Implications for Multifocal Ectopic Purkinje-Related Premature Contractions.

BACKGROUND: Multifocal ectopic Purkinje-related premature contractions (MEPPCs) are associated with SCN5A variants. However, it is not well understood why Purkinje fibers, but not ventricular myocardium, play a predominant role in arrhythmogenesis. OBJECTIVES: This study sought to explore the underlying mechanisms of MEPPC. METHODS: Whole-cell patch-clamp and molecular biology techniques were used in the present study. RESULTS: Clinical data from one patient with R814W variant showed MEPPC syndrome, which is well responsive to amiodarone. Compared with canine ventricular myocytes, Purkinje cells (PCs) had significantly larger sodium current (INa), leftward shift of INa activation and inactivation curves, suggesting higher sodium channel excitability in PCs. Real-time polymerase chain reaction and Western blot analysis showed that the mRNA and protein expression of NaVß1 and NaVß3 was higher in canine Purkinje fibers than in ventricular myocardium. INa in heterologous Chinese hamster ovary cell expression system co-expressing NaV1.5 and NaVß1/NaVß3 exhibited similar biophysical properties of INa in PCs. R814W variant shifted INa activation in a hyperdepolarized direction, caused a larger window current, and generated an outward-gating pore current at depolarized voltages. Coexpression of NaVß1/NaVß3 with Nav1.5-R814W further left-shifted INa activation and caused an even larger window current and gating pore current, suggesting higher susceptibility of Purkinje fibers to R814W variant. Amiodarone inhibited INa, shifted its inactivation to more negative voltages, and significantly decreased the window current. CONCLUSIONS: A higher expression of ß1 and ß3 subunits contributes to higher sodium channel excitability in cardiac Purkinje fibers, making them more susceptible to MEPPC.

Efficacy of Left Atrial Appendage Closure and Oral Anticoagulation After Atrial Fibrillation Catheter Ablation.

Left atrial appendage closure (LAAC) proved to be noninferior to oral anticoagulation (OAC) in nonablated patients with atrial fibrillation (AF). This study aimed to compare the efficacy and safety of LAAC with those of OAC therapy in patients after AF ablation. This study included patients who underwent catheter ablation (CA) of AF between January 2016 and December 2020. The cohort was divided into CA + LAAC and CA + OAC, where propensity score matching was used to select controls, and each group contained 682 subjects. The enrolled patients' mean age was 70.34 ± 8.32 years, and 47.3% were female; their CHA2DS2-VASc score was 3.48 ± 1.17. Baseline characteristics were similar between groups. After a 3-year mean follow-up, the incidence of thromboembolic events was 1.25 and 1.10 and that of major bleeding events was 0.65 and 1.72 per 100 patient-years in the CA + LAAC, and CA + OAC groups, respectively. The rate of thromboembolisms and major adverse cardiovascular events was similar between the 2 groups (hazard ratio [HR] 1.162, 95% confidence interval [CI] 0.665 to 2.030, p = 0.598, HR 0.711, 95% CI 0.502 to 1.005, p = 0.053); however, that of major bleeding and all-cause death was significantly reduced with LAAC (HR 0.401, 95% CI 0.216 to 0.746, p = 0.004, HR 0.528, 95% CI 0.281 to 0.989, p = 0.046). There was no significant difference in periprocedural complications (p >0.05) and the rate of AF recurrence (OAC vs LAAC: 39.44% vs 40.62%, p = 0.658). LAAC is a reasonable and safer alternative to OAC therapy in high-risk patients after AF ablation.

Novel signaling axis of FHOD1-RNF213-Col1α/Col3α in the pathogenesis of hypertension-induced tunica media thickening.

Hypertension-induced tunica media thickening (TMT) is the most important fundamental for the subsequent complications like stroke and cardiovascular diseases. Pathogenically, TMT originates from both vascular smooth muscle cells (VSMCs) hypertrophy due to synthesizing more amount of intracellular contractile proteins and excess secretion of extracellular matrix. However, what key molecules are involved in the pathogenesis of TMT is unknown. We hypothesize that formin homology 2 domain-containing protein 1 (FHOD1), an amply expressed mediator for assembly of thin actin filament in VSMCs, is a key regulator for the pathogenesis of TMT. In this study, we found that FHOD1 expression and its phosphorylation/activation were both upregulated in the arteries of three kinds of hypertensive rats. Ang-II induced actin filament formation and hypertrophy through activation and upregulation of FHOD1 in VSMCs. Active FHOD1-mediated actin filament assembly and secretions of collagen-1α/collagen-3α played crucial roles in Ang-II-induced VSMCs hypertrophy in vitro and hypertensive TMT in vivo. Proteomics demonstrated that activated FL-FHOD1 or its C-terminal diaphanous-autoregulatory domain significantly upregulated RNF213 (ring finger protein 213), a 591-kDa cytosolic E3 ubiquitin ligase with its loss-of-functional mutations being a susceptibility gene for Moyamoya disease which has prominent tunica media thinning in both intracranial and systemic arteries. Mechanistically, activated FHOD1 upregulated its downstream effector RNF213 independently of its classical pathway of decreasing G-actin/F-actin ratio, transcription, and translation, but dependently on its C-terminus-mediated stabilization of RNF213 protein. FHOD1-RNF213 signaling dramatically promoted collagen-1α/collagen-3α syntheses in VSMCs. Our results discovered a novel signaling axis of FHOD1-RNF213-collagen-1α/collagen-3α and its key role in the pathogenesis of hypertensive TMT.

Safety and efficacy of ablation for atrial fibrillation in combination with left atrial appendage occlusion in octogenarians.

BACKGROUND: Catheter ablation (CA) combined with left atrial appendage occlusion (LAAO) is a feasible approach for atrial fibrillation (AF) patients. Its role in octogenarians with AF is unclear. HYPOTHESIS: In AF patients over 80 years, CA combined with LAAO is a feasible way in restoring sinus rhythm and preventing stroke. METHODS: This is a single-center retrospective study. Patients who underwent CA and LAAO in a single procedure between March 2018 and December 2020 were included. Efficacy endpoints included procedural success rate, AF recurrence rate, and thromboembolic events. Safety endpoints included pericardial effusion/cardiac tamponade, device-related thrombus (DRT), all-cause death, and major bleeding. RESULTS: Five hundred and five patients (mean age 69.5 ± 7.7 years; 230 [45.5%] female) were included, with 46 (9.1%) patients aged ≥80 years old (octogenarian group). Prevalence of paroxysmal AF (25 [54.3%] vs. 207 [45.1%], p < 0.001) and CHA2DS2VASc score (4.1 ± 1.3 vs. 3.1 ± 1.4, p < 0.0001) were higher in octogenarian patients. There were six cases (1.2%) of pericardial effusion (all in nonoctogenarian patients). At 3 months postprocedure, 437 patients underwent TEE/CT. Thirty-two (80%) octogenarian patients and 308 (77.6%) nonoctogenarian patients had no peri-device leak. After a mean follow-up of 26.9 ± 9.1 months, AF was documented in 10 (21.7%) patients in octogenarian group and in 103 (22.4%) patients in nonoctogenarian group (p = 0.99). The annual thromboembolic risk was 2.1% and 0.8% in the octogenarian group and nonoctogenarian group, respectively. Death occurred in 16 nonoctogenarian patients. One major bleeding was recorded in the octogenarian group. CONCLUSIONS: The combination of CA and LAAO in a single procedure is a feasible treatment option in octogenarians with comparable efficacy and safety profile.

[Simulation Results and Analysis of Electric Field Distribution in Myocardial Tissue under Circular Electrode Electric Pulse Ablation].

As a new energy source for atrial fibrillation ablation, electric pulse ablation has higher tissue selectivity and biosafety, so it has a great application prospect. At present, there is very limited research on multi-electrode simulated ablation of histological electrical pulse. In this study, a circular multi-electrode ablation model of pulmonary vein will be built on COMSOL5.5 platform for simulation research. The results show that when the voltage amplitude reaches about 900 V, it can make some positions achieve transmural ablation, and the depth of continuous ablation area formed can reach 3 mm when the voltage amplitude reaches 1 200 V. When the distance between catheter electrode and myocardial tissue is increased to 2 mm, a voltage of at least 2 000 V is required to make the depth of continuous ablation area reach 3 mm. Through the simulation of electric pulse ablation with ring electrode, the research results of this project can provide reference for the voltage selection in the clinical application of electric pulse ablation.

Cadherin-11-Interleukin-6 Signaling between Cardiac Fibroblast and Cardiomyocyte Promotes Ventricular Remodeling in a Mouse Pressure Overload-Induced Heart Failure Model.

Heart failure is a serious and life-threatening disease worldwide. Cadherin-11 (Cad-11) is highly expressed in the heart and closely associated with inflammation. There is currently limited understanding on how Cad-11 contributes to cardiac remodeling and its underline molecular mechanism. We found an increased expression of Cad-11 in biopsy heart samples from heart failure patients, suggesting a link between Cad-11 and heart failure. To determine the role of Cad-11 in cardiac remodeling, Cad-11-deficient mice were used in a well-established mouse transverse aortic constriction (TAC) model. Loss of Cad11 greatly improved pressure overload-induced LV structural and electrical remodeling. IL (interleukin)-6 production was increased following TAC in WT mice and this increase was inhibited in cadherin-11-/- mice. We further tested the effect of IL-6 on myocyte hypertrophy and fibrosis in a primary culture system. The addition of hCad-11-Fc to cultured cardiac fibroblasts increased IL-6 production and fibroblast cell activation, whereas neutralizing IL-6 with an IL-6 antibody resulted in alleviating the fibroblast activation induced by hCad-11-Fc. On the other hand, cardiomyocytes were promoted to cardiomyocyte hypertrophy when cultured in condition media collected from cardiac fibroblasts stimulated by hCad-11-Fc.Similarly, neutralizing IL-6 prevented cardiomyocyte hypertrophy. Finally, we found that MAPKs and CaMKII-STAT3 pathways were activated in both hCad-11-Fc stimulated fibroblasts and cardiomyocytes treated with hCad-11-Fc stimulated fibroblast condition medium. IL-6 neutralization inhibited such MAPK and CaMKII-STAT3 signaling activation. These data demonstrate that Cad-11 functions in pressure overload-induced ventricular remodeling through inducing IL-6 secretion from cardiac fibroblasts to modulate the pathophysiology of neighboring cardiomyocytes.

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).

Left atrial appendage closure in patients with reversed chicken-wing morphology: Anatomical features and procedural strategy.

Background: Left atrial appendage (LAA) closure (LAAC) in atrial fibrillation (AF) patients with the reversed chicken-wing (RCW) LAA is challenging. Aims: To elucidate the LAAC strategy of the RCW-LAA. Methods: A total of 802 AF patients who were enrolled in the LAACablation registry for LAAC procedure were included, 55 of whom presented with the RCW-LAA. The WATCHMAN device was implanted using the standard protocol when the sheath depth was no less than the device depth (the simple group). For those with a sheath depth of less than the device depth (the complex group), device deployment was attempted with acceptable protrusion or after a repeated atrial transseptal puncture (re-ATP) at a more inferior and anterior position. The anatomical and procedural features were compared between groups and before and after the re-ATP. Results: The success rate of LAAC was significantly lower in patients with the RCW-LAA than with the other morphologies (92.7% vs. 98.8%, p = 0.001). Compared with the simple group, the complex group had shorter root depth and shorter neck length, and more LAAs in the complex group were at lower position (all p < 0.05). The sheath depth after the re-ATP was significantly greater than that before the re-ATP (18.8 ± 3.4 mm vs. 14.7 ± 2.6 mm, p < 0.001). For the patients who underwent re-ATP, the sheath went significantly deeper in successful procedures than in aborted procedures (19.7 ± 3.3 mm vs. 15.8 ± 1.8 mm, p = 0.040). Conclusions: The anatomical features of the RCW-LAA were related to the complexity of the LAAC procedure. The re-ATP at an inferior and anterior location could increase the success rate of LAAC. ClinicalTrialsgov: NCT03788941.

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.

Inhibition of Wdr5 Attenuates Ang-II-Induced Fibroblast-to-Myofibroblast Transition in Cardiac Fibrosis by Regulating Mdm2/P53/P21 Pathway.

Cardiac fibrosis is an important pathological process in many diseases. Wdr5 catalyzes the trimethylation of lysine K4 on histone H3. The effects of Wdr5 on the cardiac fibrosis phenotype and the activation or transformation of cardiac fibroblasts were investigated by Ang-II-infused mice by osmotic mini-pump and isolated primary neonatal rat cardiac fibroblasts. We found that the Wdr5 expression and histone H3K4me3 modification were significantly increased in Ang-II-infused mice. By stimulating primary neonatal rat cardiac fibroblasts with Ang II, we detected that the expression of Wdr5 and H3K4me3 modification were also significantly increased. Two Wdr5-specific inhibitors, and the lentivirus that transfected Sh-Wdr5, were used to treat primary mouse cardiac fibroblasts, which not only inhibited the histone methylation by Wdr5 but also significantly reduced the activation and migration ability of Ang-II-treated fibroblasts. To explore its mechanism, we found that the inhibition of Wdr5 increased the expression of P53, P21. Cut&Tag-qPCR showed that the inhibition of Wdr5 significantly reduced the enrichment of H3K4me3 in the Mdm2 promoter region. For in vivo experiments, we finally proved that the Wdr5 inhibitor OICR9429 significantly reduced Ang-II-induced cardiac fibrosis and increased the expression of P21 in cardiac fibroblasts. Inhibition of Wdr5 may mediate cardiac fibroblast cycle arrest through the Mdm2/P53/P21 pathway and alleviate cardiac fibrosis.