Outcome and safety of intracardiac echocardiography guided left atrial appendage closure within zero-fluoroscopy atrial fibrillation ablation procedures.

BACKGROUND: Simultaneous atrial fibrillation (AF) catheter ablation and left atrial appendage closure (LAAC) are sometimes recommended for both rhythm control and stroke prevention. However, the advantages of intracardiac echocardiography (ICE) guidance for this combined procedure have been scarcely reported. We aim to evaluate the clinical outcomes and safety of ICE-guided LAAC within a zero-fluoroscopy catheter ablation procedure. METHODS AND RESULTS: From April 2019 to April 2020, 56 patients with symptomatic AF underwent concomitant catheter ablation and LAAC. ICE with a multi-angled imaging protocol mimicking the TEE echo windows was used to guide LAAC. Successful radiofrequency catheter ablation and LAAC were achieved in all patients. Procedure-related adverse event rate was 3.6%. During the 12-month follow-up, 75.0% of patients became free of arrhythmia recurrences and oral anticoagulants were discontinued in 96.4% of patients. No ischemic stroke occurred despite two cases of device-related thrombosis versus an expected stroke rate of 4.8% based on the CHA2 DS2 -VASc score. The overall major bleeding events rate was 1.8%, which represented a relative reduction of 68% versus an expected bleeding rate of 5.7% based on the HAS-BLED score of the patient cohort. The incidence of iatrogenic atrial septal defect secondary to single transseptal access dropped from 57.9% at 2 months to 4.2% at 12 months TEE follow-up. CONCLUSION: The combination of catheter ablation and LAAC under ICE guidance was safe and effective in AF patients with high stroke risk. ICE with our novel protocol was technically feasible for comprehensive and systematic assessment of device implantation.

A comparative study of pericardial effusion and pleural effusion after cryoballoon ablation or radiofrequency catheter ablation of atrial fibrillation.

INTRODUCTION: The incidence and clinical outcome of pericardial and pleural effusion after cryoballoon ablation (CBA) or radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) have not been fully investigated. METHODS: A total of 60 patients with paroxysmal AF were treated with either CBA (n = 30) or RFCA (n = 30) groups, with assessment of serum troponin I level, left atrial pulmonary vein computed tomography (CT) angiography and echocardiography within 24 hours before ablation, and serum troponin I level at 12 hours, and chest CT and echocardiography within 24 hours postablation. Repeat chest CT was performed 1 month after the index procedure in patients with pericardial or pleural effusion. RESULTS: With similarly distributed baseline characteristics, the CBA group relative to the RFCA group had postablation: higher serum troponin I level (13.48 vs 1.84 µg/L, P < .001); similarly high pericardial effusion rates on chest CT (80% vs 93.3%, P > .05), with chest CT yielding significantly higher detection rate than echocardiography; similarly high pleural effusion rates on chest CT (73.3% vs 80%, P > .05); and smaller maximum depths on chest CT cross-section of pericardial effusion (5.21 ± 3.37 vs 7.13 ± 2.68 mm, P < .05) and pleural effusion bilaterally (left: 4.16 ± 4.90 vs 6.96 ± 5.42 mm; right: 5.04 ± 4.46 vs 7.55 ± 4.95 mm, both P < .05). The effusions self-resolved within a mean period of 1 month. CONCLUSIONS: Both CBA and RFCA were associated with high rates of pericardial and pleural effusion, with RFCA yielding numerically higher incidence and significantly higher effusion extent, and chest CT significantly higher detection rates than echocardiography.

Young Patients with Unknown Stroke and Little P Wave in ECG.

Here we report two young patients with atrial fibrillation/atrial flutter complicated with cardiogenic cerebral embolism. Electrophysiological study revealed a large area of low-voltage zone or area of electric silence in both sides of the atrium during restoration of sinus rhythm, and the echocardiogram showed loss of mechanical function of the atrium. The electrical-mechanical dysfunction of the atrium was considered to be the cause of embolic event in this type of patient who was "very low" stroke risk atrial fibrillation or atrial flutter. The idiopathic, fibrotic atrial cardiomyopathy may be underlying in these patients.

Influence of Body Mass Index on the Activated Clotting Time Under Weight-Based Heparin Dose.

BACKGROUND: Activated clotting time (ACT) has been successfully applied during percutaneous coronary intervention (PCI) to monitor the extent of thrombin inhibition and anti-coagulation from unfractionated heparin (UFH) aiming to reduce the incidence of thrombotic adverse events and hemorrhagic complications. And this investigation was to explore the influence of body mass index (BMI) on ACT in patients received weight-based dose of UFH during PCI treatment. METHODS: 78 male patients undergoing coronary angiography or PCI treatment with a mean age of 63.86 ± 6.89 years were enrolled in this study. The patients were statistically divided into four quartiles according to their BMI. The ACT values were recorded as ACT0 , ACT5 , ACT10 , ACT30 and ACT60 , respectively. Taking the preoperative ACT0 as reference, and the differences of the other ACT values with ACT0 was indicated as ΔACTs. ACT values peaked at 5 min in 33.33% of the patients, 10 min in 51.33% of the patients and 30 min in 15.34% of the patients, respectively. RESULTS: In addition, significant differences were found in overall maximum post-UFH ACT values among all BMI quartiles. UFH doses per blood volume were significantly different among the BMI quartiles, showing a positive association with BMI quartiles; further evidence revealed that the areas under the ΔACT-time curves increased gradually from quartile I to quartile IV. The proportions of ACT60 > 250 s and ACT60 > 300 s were found to be positively correlated with the increased BMI at 60 min after heparin loading. CONCLUSIONS: The results of our study have shown that a standardized dosing nomogram that uses the actual body weight to calculate the heparin doses may result in UFH overdose for patients with higher BMI compared to patients with lower BMI.

Overexpression of microRNA-133a inhibits ischemia-reperfusion-induced cardiomyocyte apoptosis by targeting DAPK2.

To examine microRNA-133a (miR-133a) endogenous expression in cardiomyocytes after ischemia-reperfusion (I/R) injury and study the effects of miR-133a overexpression on I/R injury-induced cardiomyocyte apoptosis. Dual-Luciferase Reporter Assay detected dynamic expression of miR-133a. In an in vitro hypoxia-reoxygenation (HR) injury model and an in vivo rat model of I/R injury, rat cardiomyocytes were transfected with miR-133a mimic to test the effects of miR-133a overexpression on apoptosis. MiR-133a and Death Associated Protein Kinase 2 (DAPK2) mRNA expression was measured using real-time-PCR, and DAPK2 protein expression was detected by western blotting. Annexin V-fluorescein isothiocyanate/propidium iodide (PI) double-staining measured the apoptosis rate in H9C2 cells and transferase dUTP nick end labeling assay quantified the cardiomyocyte apoptosis rate in tissues obtained from in vivo the rat model. DAPK2 is a target of miR-133a. Both in vitro and in vivo results confirmed that after expression of miR-133a mimics, miR-133a levels increased, which was accompanied by decrease in DAPK2 mRNA and protein expression. In H9C2 cells, HR injury caused a sharp decrease in miR-133a expression and a significant upregualtion of DAPK2 mRNA and protein levels. However, exogenous miR-133a expression led to a significant reduction in DAPK2 mRNA and protein levels despite HR injury. Similar results were obtained from in vivo I/R injury model. After HR injury or I/R injury the apoptosis rate of myocardial cells was highly elevated and decreased significantly only after transfection of miR-133a into cardiomyocytes. MiR-133a overexpression may inhibit I/R injury-mediated cardiomyocyte apoptosis by targeting DAPK2, leading to reduced DAPK2 protein, thus miR-133a may potentially have a high therapeutic value in I/R injury.

[Relationship between antithrombin-III value with acute coronary syndrome and preprocedural TIMI flow grade].

OBJECTIVE: To explore the differences of antiprothrombin-III (AT-III) value in patients with acute coronary syndrome (ACS) and stable angina pectoris (SAP) and examine the association of AT-III value with preprocedural thrombolysis in myocardial infarction (TIMI) flow in ACS patients. METHODS: This study prospectively included 121 hospitalized ACS patients between February 2011 to June 2011, including ST-segment elevation myocardial infarction (STEMI, n = 50), non-ST segment elevation myocardial infarction (NSTEMI, n = 32) and unstable angina (UAP, n = 39). Meanwhile, 50 SAP cases during the same period were selected as the control group. The AT-III levels were measured by chromogenic substrate method before coronary angiography for all patients. RESULTS: (1) The AT-III levels were significantly lower in the ACS patients than those in the SAP cases. (2) In the STEMI subgroup, the AT-III levels were markedly lower in the patients with preprocedural TIMI flow grade ≤ 2 versus those with preprocedural TIMI flow grade 3 (86% ± 11% vs 93% ± 9%, P < 0.05). (3) In the USTEMI/UAP subgroup, the mean levels of AT-III were obviously lower in the patients with preprocedural TIMI flow grade ≤ 2 than those with preprocedural TIMI flow grade 3 (85% ± 8% vs 95% ± 8%, P < 0.01) and were notably lower in the patients with the culprit lesion stenosis ≥ 70% versus those with stenosis < 70% (88% ± 9% vs 94% ± 9%, P < 0.01). (4) Multivariable analysis identified AT-III value as an independent predictor of impaired preprocedural TIMI flow grade of culprit coronary artery in ACS patients. CONCLUSION: The AT-III levels were significantly lower in the ACS patients than those in the SAP patients. The activity of AT-III is positively correlated with the TIMI flow grade in ACS patients. In contrast, the activity of AT-III is negatively correlated with the severity of culprit vessel stenosis in the patients with NSTEMI. Thus AT-III level may be used to distinguish high-risk populations in ACS patients at an early stage.

Assessment of High-Power Catheter Ablation in Patients With Atrial Fibrillation: A Meta-Analysis.

Background: High-power radiofrequency (RF) catheter ablation was considered as a promising alternative strategy to conventional-power ablation in the treatment of patients with atrial fibrillation (AF). This study sought to compare the efficacy and safety of high-power energy delivery to that of conventional-power setting in AF catheter ablation. Methods: We performed a systematic review of relevant literature in Pubmed, Embase, Cochrane library, and Google Scholar database. Sixteen eligible studies totaling 3,307 patients (1,929 for high-power ablation; 1,378 for conventional-power ablation) met inclusion criteria. Results: During a median 12 month follow-up, high-power ablation showed a significantly higher AF/atrial tachycardia-free survival rate in comparison with conventional-power ablation (risk ratio [RR] 1.09, 95% CI 1.02 to 1.15, p = 0.008). Notably, a high-power strategy convincingly decreased the procedure time (weighted mean difference [WMD] -46.11 min, 95% CI -59.15 to -33.07, p < 0.001) and RF ablation time (WMD -19.19 min, 95% CI -24.47 to -13.90, p < 0.001), along with reduced fluoroscopy time (WMD -7.82 min, 95% CI -15.13 to -0.68, p = 0.036). In addition, there was no perceptible difference in the potential risk of procedure-related complications between these two approaches (RR 0.81, 95% CI 0.48 to 1.37, p = 0.428). Conclusions: High-power RF catheter ablation was associated with an improvement in long-term sinus rhythm maintenance for treatment of AF, without exacerbating the risk of adverse events during the procedure. Impressively, high-power pulmonary vein isolation had the potential to shorten the application duration and minimize fluoroscopic exposure.

Melatonin against Myocardial Ischemia-Reperfusion Injury: A Meta-analysis and Mechanism Insight from Animal Studies.

AIMS: Myocardial reperfusion damage after severe ischemia was an important issue during a clinical practice. However, the exacted pathogenesis involved remained unclear and also lacks effective interventions. Melatonin was identified to exert protective effects for alleviating the myocardial I/R injury. This meta-analysis was determined to evaluate the efficacy of melatonin treatment against reperfusion insult and further summarize potential molecular and cellular mechanisms. METHODS AND RESULTS: 15 eligible studies with 211 animals (108 received melatonin and 103 received vehicle) were included after searching the databases of PubMed, MEDLINE, Embase, and Cochrane. Pretreatment with melatonin was associated with a significant lower infarct size in comparison with vehicle in myocardial I/R damage (WMD: -20.45, 95% CI: -25.43 to -15.47, p < 0.001; I 2 = 91.4%, p < 0.001). Evidence from subgroup analyses and sensitivity analysis indicated the robust and consistent cardioprotective effect of melatonin, while the metaregression also did not unmask any significant interactions between the pooled estimates and covariates (i.e., sample size, state, species, study type, route of administration, and duration of reperfusion, along with timing regimen of pretreatment). Accordingly, melatonin evidently increased EF (WMD: 17.19, 95% CI: 11.08 to 23.29, p < 0.001; I 2 = 77.0%, p < 0.001) and FS (WMD: 14.18, 95% CI: 11.22 to 17.15, p < 0.001; I 2 = 3.5%, p = 0.387) in the setting of reperfusion damage. CONCLUSIONS: Melatonin preadministration conferred a profound cardioprotection against myocardial I/R injury in preclinical studies.

Islet transplantation attenuates cardiac fibrosis in diabetic rats through inhibition of TGF-ß1/Smad3 pathway.

Although islet transplantation has been identified as a promising endocrine replacement treatment for patient with diabetes mellitus (DM), it still remains unclear whether islet transplantation can inhibit the diabetic-induced myocardial injury and subsequent adverse ventricular remodeling. Here, we sought to explore the molecular mechanism underlying the cardioprotective effect of islet transplantation. We established the diabetic rat model by intraperitoneal injection of STZ, which was followed by either islet transplantation or conventional insulin treatment. Compared with insulin treatment, islet transplantation further reduced the elevated blood glucose which was nearly restored to normoglycaemia. In addition, islet transplantation attenuated the increased levels of cTn-I and CK-MB, cleaved-caspase-3 in response to DM, and ameliorated diabetic-induced cardiac hypertrophy and interstitial fibrosis, along with improved extracellular matrix (ECM) deposition. Moreover, diabetic rats that underwent islet transplantation had lower expression of TGF-ß1 and lower phosphorylation levels of Smad3. Therefore, islet transplantation exerted protective effect against diabetic-induced myocardial injury and fibrotic remodeling through deactivation of TGF-ß1/Smad3 signaling pathway.

[Effects of endothelial progenitor cells and endothelial outgrowth cells in repair of injured carotid vessel: a comparative study with rabbits].

OBJECTIVE: To compare the effects of endothelial progenitor cells (EPCs) and endothelial outgrowth cells (EOCs) on the repair of injured vessels. METHODS: Mononuclear cells (MNCs) were isolated from rabbit peripheral blood by density-gradient centrifugation. EPCs and EOCs were obtained from the culture of MNCs and labeled with the cell dye CM-DiI for cells tracking. Eighteen rabbits were made into models of balloon-injured common carotid artery and then divided into 2 equal groups to undergo injection of the suspensions of EPCs or EOCs. Nine rabbits underwent injection of normal saline as control group. Four weeks after transplantation, the rabbits underwent venous injection of Evans blue, and then were killed with the injured vessels taken out. Fluorescence-labeled both types of cells, endothelial regeneration rate and IA/MA ratio were detected. RESULTS: Four weeks after transplantation, fluorescence-labeled EPCs and EOCs were detected within the tunica intima, mostly in the neointima and on the luminal surface of injured vessel. The endothelialization area of denuded vessel of the EPC and EOC groups were 91.6% +/- 3.6% and 89.1% +/- 6.3% respectively, both significantly larger than that of the control group (62.1% +/- 7.5%, both P < 0.01), however, without significant difference between the 2 former groups (P = 0.50). The intima area/media area ratio of the EPC and EOC groups were 0.48 +/- 0.11 and 0.44 +/- 0.06, both significantly lower than that of the control group (0.88 +/- 0.14, both P < 0.01), however, without significant difference between the 2 former groups (P = 0.59). CONCLUSION: Transplantation of both EPCs and EPCs accelerate the reendothelialization and reduce the neointimal formation with similar effects.

Evaluation on the efficacy and safety of domestic bivalirudin during percutaneous coronary intervention.

BACKGROUND: Bivalirudin was widely used as an anticoagulant during coronary interventional procedure in western countries. However, it was not available in China before this clinical trial was designed. This randomized, single-blind and multicenter clinical trial aimed to evaluate the efficacy and the safety of domestic bivalirudin during percutaneous coronary intervention (PCI). METHODS: A randomized, single-blind, multicenter trial was designed. Elective PCI candidates in five centers were randomized into a bivalirudin group and a heparin group, which were treated with domestic bivalirudin and non-fractional heparin during the PCI procedure. The efficacy was evaluated by comparing the activated coagulation time (ACT), the procedural success rate (residual stenosis < 20% in target lesions without any coronary artery related adverse events within 24 hours after PCI), and the survival rate without major adverse cardiac events at 30 days after PCI between the two groups. Safety was evaluated by the major/minor bleeding rate. RESULTS: A total of 218 elective PCI patients were randomized into a bivalirudin group (n = 110) and heparin group (n = 108). Except for two patients needing additional dosing in the heparin group, the ACT values of all other patients in both groups were longer than 225 seconds at 5 minutes after the first intravenous bolus. Procedural success rates were respectively 100.0% and 98.2% in the bivalirudin group and heparin group (P > 0.05). Survival rates without major adverse cardiac events at 30 days after PCI were 100.0% in the bivalirudin group and 98.2% in the heparin group (P > 0.05). Mild bleeding rates were 0.9% and 6.9% (P < 0.05) at 24 hours, and 1.9% and 8.8% (P < 0.05) at 30 days after PCI in the bivalirudin group and heparin group respectively. There was one severe gastrointestinal bleeding case in the heparin group. CONCLUSIONS: Domestic bivalirudin is an effective and safe anticoagulant during elective PCI procedures. The efficacy is not inferior to heparin, but the safety is superior to heparin.

[Isolation, culture and identification of two types of endothelial progenitor cells from peripheral blood in rabbits].

AIM: To investigate how to isolate, culture and identify two types of endothelial progenitor cells from peripheral blood in rabbits. METHODS: Mononuclear cells(MNCs) were isolated from rabbit peripheral blood. Endothelial progenitor cells (EPCs) and endothelial outgrowth cells (EOCs) were obtained from MNCs through different ways of isolation and culture. Two types of cells were assessed by DiI-ac-LDL uptake and lectin binding, and then they were identified by immunofluorescence of flk-1, immunocytochemistry of CD34 and VIII factor related antigen and vasculogenesis activity in vitro. RESULTS: Two types of endothelial progenitor cells were obtained from rabbit peripheral blood through different ways of isolation and culture. EPCs on the seventh day and EOCs on the sixteenth day were positive for ac-LDL uptake and lectin binding, and both of them expressed CD34, flk-1 and VIII factor related antigen. EOCs were assembled into primitive vascular tube-like structures when plated in matrigel. CONCLUSION: EPCs and EOCs could be obtained from rabbit peripheral blood when different ways of isolation and culture were performed. The system of cell culture can be applied to subsequent experiments in cell transplantation.