Optimal endpoint for catheter ablation of longstanding persistent atrial fibrillation: A randomized clinical trial.

BACKGROUND: In longstanding persistent atrial fibrillation (LPeAF), the ideal endpoint of ablation remains to be determined. This study was to explore the value of pursuing AF termination or no with the same strategy during ablation on the long-term outcomes in patients with LPeAF. METHODS: Utilized "CCL" strategy is a fixed ablation approach consisting of circumferential pulmonary vein antrum isolation, ablation of complex fractionated atrial electrogram, and linear ablation between two anatomical structures (the mitral isthmus, left atrial roof). Note that 400 patients were randomized to group A (technical endpoint) and group B (pursuing AF termination). RESULTS: A group with technical endpoint had lower rate of acute AF termination (AF→sinus rhythm, 3.5% vs 18.1%; AF→atrial tachycardia, 23.7% vs 44.7%; P < 0.01) and shorter duration of ablation (164.9 ± 20.8 vs 223.4 ± 24.9, P < 0.01), radiofrequency delivery time (69.8 ± 18.1 vs 102.2 ± 26.3, P < 0.01), and x-ray exposure time (18.2 ± 8.8 vs 27.9 ± 12.4, P < 0.01) than those in B group (pursuing AF termination). During follow-up, freedom from atrial arrhythmias did not differ between the two groups after a single ablation procedure (46.5% vs 54.3%, P=0.12) and the final ablation procedure (60.1% vs 65.8%, P  =  0.24). CONCLUSION: In patients of LPeAF, pursuing AF termination during ablation was associated with similar long-term clinical outcome compared to that with technical endpoint. Ablation to termination is not the best strategy during ablation.

A clinical study on the electrophysiological characteristics of patients without recurrence after ablation of persistent atrial fibrillation.

BACKGROUND: The electrophysiological characteristics of patients without recurrence after ablation of persistent atrial fibrillation (AF) have not been systematically determined. This study compared the electrophysiological characteristics in patients with and without recurrence of AF after persistent AF ablation. METHODS: Forty-five patients without recurrence of AF after persistent AF ablation were enrolled to assess electrophysiological characteristics including pulmonary vein (PV) reconnection, the mitral isthmus (MI) line and the roof line reconduction. Ninety-five patients with recurrence of AF after ablation were used as the control group. RESULTS: Among patients without recurrence, recovery of PV conduction was observed in 37 of 45 (82.2%) patients: 3/45 (6.7%) reconnection in 4 veins, 7/45 (15.6%) in 3 veins, 11/45 (24.4%) in 2 veins, and 16/45 (35.6%) in 1 vein. No significant differences were seen in the proportion of patients with PV reconnection compared to patients with recurrence (p>0.05). Among patients without recurrence, the MI line reconduction was observed in 3/45 (6.7%) patients; the roof line conduction was observed in 5/45 (11.1%) patients. In comparison, patients with clinical recurrence of AF had recovery of the MI line conduction in 27/95 (28.4%) and recovery of the roof line conduction in 26/95 (27.4%). Significant differences were seen between these two groups (6.7% vs 28.4%, p=0.004; 11.1% vs 27.4%, p=0.031). CONCLUSION: Although a high incidence of PV reconnection was similarly observed in patients with and without recurrence of AF, a lower incidence of lines reconduction was observed in patients without recurrence of AF.

Development of a Method for the Analysis of Multiclass Antibiotic Residues in Milk Using QuEChERS and Liquid Chromatography-Tandem Mass Spectrometry.

A precise and simplified method of sample preparation for the simultaneous quantification of the antibiotics ß-lactam, macrolide, tetracycline, sulfonamide, and quinolone in bovine milk was developed. The central composite design of response surface methodology was used to design and optimize the method for the determination of six different antibiotic residues in milk. The recovery of each antibiotic was studied using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Octadecylsilane (C18), primary secondary amine (PSA), and sodium acetate (Na acetate) were the main factors affecting the recovery of each antibiotic. After optimization, the maximum predicted recovery rate was 84.18% for erythromycin under the optimized conditions of 101.20 mg C18, 52.00 mg PSA, and 1.01 g Na acetate. The recovery rates of the five other antibiotic residues ranged from 86.09% to 115.99%. The results suggested that modified QuEChERS could effectively be implemented in the analysis of antibiotic residues in milk.

Optimal rhythm-control strategy for recurrent atrial tachycardia after catheter ablation of persistent atrial fibrillation: a randomized clinical trial.

AIM: Although catheter ablation (CA) has replaced antiarrhythmic drugs (AAD) as first-line treatment in selected patients with atrial fibrillation (AF), optimal treatment of recurrent atrial tachycardia (AT) after AF ablation remains unclear. This parallel randomized controlled study compared CA vs. AAD for recurrent AT after persistent AF ablation. METHODS AND RESULTS: Two-hundred and one patients (aged 59.1 ± 10.9 years, 68.7% male) with recurrent AT after persistent AF ablation were enrolled and randomized to either CA (n = 101) or AAD (n = 100) treatment. Primary endpoint was freedom from recurrent atrial tachyarrhythmia (ATa, including AT and AF) at 24-month follow-up. Composite secondary endpoints comprised procedural complications, long-term morbidity and improvement in quality of life (QoL). On an intention-to-treat basis, the CA group had a higher rate of freedom from recurrent ATa (56.4 vs. 34.0%; P = 0.001). Adjusted Cox regression analysis showed a significant treatment effect with a hazard ratio of 0.538 (95% CI: 0.355-0.816) in favour of CA. There was a higher proportion of periprocedural complications in the CA group (7.9 vs. 0; P = 0.012), and of long-term adverse events in the AAD group (10.9 vs. 24.0%; P = 0.014). Quality of life was significantly higher for CA. CONCLUSIONS: This study demonstrates superiority of CA over AAD for recurrent AT after persistent AF ablation with regard to SR maintenance, long-term safety and QoL improvement. However, CA use might be limited by a higher risk for periprocedural complications.

Enhanced production of Monacolin K by addition of precursors and surfactants in submerged fermentation of Monascus purpureus 9901.

The main problem in Monacolin K (MK) production by submerged fermentation of Monascus purpureus is low productivity. In this study, on one hand, addition of precursors was used to activate the biosynthesis of MK. When 4.0 g/L of sodium citrate was supplemented at the 48th H of the fermentation, the final MK production reached to 1,658.9 ± 28.5 mg/L after 20 day of fermentation, which was improved by 52.6% compared with that of the control. On the other hand, addition of surfactants could increase the permeability of cell membrane, thus driving more intracellular metabolites secreted into the fermentation broth and alleviating the product inhibition. When 40.0 g/L of Triton X-100 was added at the beginning of the fermentation, the final MK production reached to 2,026.0 ± 30.4 mg/L after 20 day of fermentation, which was improved by 84.9% compared with that of the control. These results are helpful to provide some new insights into the biosynthetic regulation on MK production; the approach can be applied to other fungal fermentation processes for enhancing production of useful metabolites.

Benefits and risks of additional ablation of complex fractionated atrial electrograms for patients with atrial fibrillation: a systematic review and meta-analysis.

BACKGROUND: The benefits and risks of additional complex fractionated atrial electrograms (CFAE) ablation in patients with atrial fibrillation (AF) remain unclear. METHODS: Trials were identified in PubMed, Embase, Web of Science, and Cochrane Database, reviews, and reference lists of relevant papers. The primary end point was the recurrence of atrial arrhythmias after a single ablation. RESULTS: We meta-analyzed 11 studies (total, n=983) using random-effects model to compare PVI (n=478) with PVI plus CFAE ablation (PVI+CFAE) (n=505). Additional CFAE ablation reduced recurrence of atrial tachyarrhythmia after a single procedure (pooled RR 0.73; 95% CI 0.61, 0.88; P=0.0007) at ≥ 3-month follow-up. There was no evidence of heterogeneity among studies (I(2)=33%). Subgroup analysis demonstrated that additional CFAE ablation reduced rates of recurrence in nonparoxysmal AF (RR 0.68; 95% CI 0.47, 0.99; P=0.05), whereas had no effect on patients with paroxysmal AF (RR 0.79; 95% CI 0.59, 1.06; P=0.12). Eight studies reported results of post-procedure ATs. The addition of CFAE ablation increased the rate of post-procedure ATs (RR 1.77; 95% CI 1.02, 3.07; P=0.04). Additional CFAE ablation significantly increased mean procedural times (245.4+75.7 vs. 189.5+62.3 min, P<0.001), mean fluoroscopy (72.1+25.6 vs. 59.5+19.3 min, P<0.001), and mean RF energy application times (75.3+38.6 vs. 53.2+27.5 min, P<0.001). CONCLUSIONS: The adjunctive CFAE ablation could provide additional benefit in terms of reducing recurrence of atrial tachyarrhythmia for patients with nonparoxysmal AF but not for patients with paroxysmal AF after a single procedure with or without antiarrhythmic drugs (AADs). The main risk of adjunctive CFAE ablation is the increasing rate of untraceable postablation ATs.

Comparison of catheter ablation and surgical ablation in patients with long-standing persistent atrial fibrillation and rheumatic heart disease: a four-year follow-up study.

BACKGROUND: In our previous prospective and randomized study, we have demonstrated that the concomitant surgical ablation using saline-irrigated cooled tip radiofrequency ablation (SICTRA) system is more effective than subsequent circumferential pulmonary vein isolation (CPVI) combined with substrate modification in treating patients with long-standing persistent atrial fibrillation (LS-AF) and rheumatic heart disease (RHD) undergoing cardiac surgery during middle-term follow-up. Whether this strategy also decreases longer-term arrhythmia recurrence is unknown. This study describes the 4-year efficacy of SICTRA for these patients. Furthermore, we seek to compare the electrophysiological characteristics for recurrent atrial tachyarrhythmia (ATa) at the session of catheter ablation between two groups. METHODS: Long-term follow-up was performed in 95 patients who underwent the catheter ablation strategy (n=47, Group A) or SICTRA (n=48, Group B) combined with valvular surgery for symptomatic LS-AF patients with RHD. RESULTS: After one procedure, Group B had a significantly higher freedom from ATa compared with Group A (29/48 vs 15/47, P=0.005) after a mean follow-up of 54 months (range 48 to 63 months). Catheter-based mapping and ablation of recurrent ATa showed larger amounts of macro-reentrant atrial tachycardias (ATs) in Group B and higher incidence of pulmonary vein (PV) recovery in Group A. After multiple catheter ablations for recurrent ATa, sinus rhythm (SR) could be maintained equally between two groups. CONCLUSIONS: Single procedure success seems to be higher with SICTRA but repeated catheter ablation potentially results in comparable outcomes in treating patients with LS-AF and RHD during long-term follow-up. More macro-reentrant ATs and more PV recoveries are identified to be responsible for ATa in SICTRA and catheter ablation group, respectively.

Efficacy and safety of catheter ablation for long-standing persistent atrial fibrillation in women.

OBJECTIVES: It is uncertain whether gender affects the outcomes of catheter ablation (CA) for atrial fibrillation (AF). The objective of the study is to evaluate the efficacy and safety of CA for long-standing persistent AF in women. METHODS: Between January 2010 and May 2011, 220 consecutive patients (73 females, 33.2%), with long-standing persistent AF who underwent CA were prospectively recruited. Gender-related differences in clinical presentation, periprocedural complications, and outcomes were compared. RESULTS: Women were less likely to have lone AF than men (27.4% vs 47.6%; P = 0.004). The incidence of rheumatic heart disease was higher in women (19.2% in women vs 1.4% in men; P < 0.001). Women had a lower initial ablation success rate than men (35.6% vs 57.1%; P = 0.003). Hematomas occurred more often in women (6.8% in women vs 0.7% in men; P = 0.027). A Cox regression analysis demonstrated total duration of AF (per month, hazard ratio [HR] 1.003, confidence interval [CI] 1.001-1.006; P = 0.006) and gender (HR 1.663, CI 1.114-2.485; P = 0.013) as the independent predictors for recurrence after the first CA. CONCLUSIONS: Women and long AF duration were closely related to the recurrence of AF after the first ablation in patients with long-standing persistent AF. Women also had a higher risk of vascular complications.

Evaluation of linear lesions in the left and right atrium in ablation of long-standing atrial fibrillation.

BACKGROUND: This randomized prospective study compared three ablation strategies in patients with long-standing persistent atrial fibrillation (LPeAF). It also explored the best procedural endpoint from among the following: circumferential pulmonary vein isolation (PVI) + left atrial (LA) linear lesions (roofline, mitral isthmus) + complex fractionated atrial electrogram (CFAE) ablation, PVI + LA linear lesions + cavotricuspid isthmus (CTI) ablation + CFAE ablation, and PVI + CFAE ablation. METHODS AND RESULTS: A total of 210 patients with LPeAF referred for catheter ablation were enrolled and randomized into three ablation groups. The patients in group A (n = 70) underwent PVI followed by LA linear and CFAE ablation; in 93% of patients the primary endpoint was achieved (five patients with incomplete linear lesions). Of the 70 patients in group B who were subjected to PVI followed by LA linear, CFAE, and CTI ablations, in 94% of patients the primary endpoint was achieved (four patients with incomplete linear lesions). All patients in group C (n = 70) successfully underwent PVI and CFAE ablation. Direct current cardioversion was performed upon PVI, CFAE elimination, and completion of linear lesions. Patients were followed-up for atrial tachyarrhythmia recurrence for at least 24 months. After a single ablation procedure, group C (36%) exhibited the lowest success compared with group A (54%) and group B (51%) (P = 0.06). At the mean follow-up of 32 ± 9 months after the final ablation procedure, 53 patients (76%) in group A, 53 (76%) in group B, and 41 (59%) in group C were in sinus rhythm without antiarrhythmic drugs (P = 0.03). CONCLUSIONS: In LPeAF, linear lesions in the LA help improve outcome of ablation, additional CTI ablation does not.

The impact of age on the efficacy and safety of catheter ablation for long-standing persistent atrial fibrillation.

BACKGROUND: Catheter ablation (CA) has been the most effective treatment for both paroxysmal and persistent atrial fibrillation (AF). However, the impact of age on CA for persistent AF is not well defined. METHODS: Between January 2010 and August 2011, 258 consecutive patients (85 females, 32.9%), with long-standing persistent AF who underwent CA were prospectively recruited. Age-related differences in clinical presentation, peri-procedural complications, and outcomes were compared. RESULTS: The study population included 258 patients (85 females, 32.9%): 71 patients in Group I (≤ 55 years), 89 patients in Group II (56-65 years), and 98 patients in Group III (≥ 66 years). Younger patients were more likely to have lone AF (49.3% in Group I, 32.6% in Group II, and 30.6% in Group III; P = 0.029). There was a significant difference in the success rate with advancing age after a single CA (69.0% in Group I, 50.6% in Group II, 40.8% in Group III; P = 0.001). A Cox regression analysis demonstrated age (for each 10 years increase, HR 1.307, CI 1.081-1.580; P = 0.006), sex (HR 1.460, CI 1.017-2.097; P = 0.040) and total AF duration (per year, HR 1.033, CI 1.006-1.060; P = 0.015) as the independent predictors for recurrence after the first CA. However, there was no significant difference in the incidence of peri-procedural complications among the three groups. CONCLUSIONS: In this consecutive series of patients with long-standing persistent AF, female gender, total AF duration and advanced age were associated with the success of a single CA. The overall rate of complications was similar among all age groups.

Ablation of atrial tachycardia occurring after catheter ablation of atrial fibrillation in patients with corrected rheumatic valve disease.

OBJECTIVE: The purpose of this study is to investigate the mechanism and the effectiveness of ablation of atrial tachycardia (AT) recurring after atrial fibrillation (AF) ablation in patients with rheumatic valvular disease (RVD) and mitral valve prosthesis. METHODS: Twenty-eight consecutive patients with RVD and mitral valve prosthesis and a 1:2 matched control group (n = 56) without RVD underwent reablation for recurrent AT after catheter ablation of long-standing persistent AF. RESULTS: Macro- or localized reentrant ATs were identified in 47 (87 %) of 54 ATs from RVD group and in 65 (78.3 %) of 83 ATs from control. There were more average ATs per patient in the RVD group than in the control (1.9 ± 0.6 vs.1.5 ± 0.6, P = 0.002). The proportion of patients having ≥2 ATs was significantly higher in the RVD group than in the control (78.6 vs.41.1 %, P = 0.001). In the RVD group, ATs were successfully ablated in 44 (81.5 %) of 54 ATs and terminated in 18 (64.3 %) of 28 patients. In the control, ATs were successfully ablated in 72 (86.7 %) of 83 ATs and terminated in 45 (80.4 %) of 56 patients, P = 0.54 and 0.10, respectively. After a mean follow-up of 13 months, 16 patients (57.1 %) from the RVD group and 45 patients (80.4 %) from the control were free of further recurrence, P = 0.02. CONCLUSIONS: Macro- or localized reentries were the predominant type of recurrent AT after long-standing persistent AF ablation in both the RVD and the control groups. Compared with patients without RVD, patients with RVD had more average number of ATs and had higher probability of further recurrence despite the similar acute effectiveness of reablation.

Initial defibrillation versus initial chest compression in a 4-minute ventricular fibrillation canine model of cardiac arrest.

OBJECTIVE: Previous laboratory and clinical studies have demonstrated that chest compression preceding defibrillation in prolonged ventricular fibrillation (VF) increases the likelihood of successful cardiac resuscitation. The lower limit of VF duration when preshock chest compression provides no benefit has not been specifically studied. We aimed to study the effect of order of defibrillation and chest compression on defibrillation and cardiac resuscitation in a 4-minute VF canine model of cardiac arrest. DESIGN: Prospective, randomized animal study. SETTING: Key Laboratory of Cardiovascular Remodeling and Function Research and Department of Cardiology, QiLu Hospital. SUBJECTS: Twenty-four domestic dogs. INTERVENTIONS: VF was induced in anesthetized and ventilated canines. After 4 minutes of untreated VF, animals were randomly assigned to receive shock first or chest compression first. Animals in the shock-first group received an immediate single countershock of 360 J for <10 seconds, then 200 immediate compressions before pulse check or rhythm reanalysis. The ratio of compression to ventilation was 30:2. Interruptions to deliver rescue breaths were eliminated in this study. Animals in the chest compression-first group received 200 chest compressions before a single countershock; the other interventions were the same as for the shock-first group. End points were restoration of spontaneous circulation (ROSC), defined as spontaneous systolic arterial pressure >50 mm Hg, when epinephrine (0.02 mg/kg intravenously) was given, and resuscitation, defined as maintaining systolic arterial pressure >50 mm Hg at the 24-hour study end point. MEASUREMENTS AND MAIN RESULTS: In the shock-first group, all animals achieved ROSC, and ten of 12 survived at the 24-hour study end point. In the chest compression-first group, 11 of 12 animals achieved ROSC, and nine of 12 survived at the 24-hour study end point. CONCLUSIONS: In this 4-minute VF canine model of cardiac arrest, the order of initial defibrillation or initial chest compression does not affect cardiac resuscitation.