Catheter ablation of atrial fibrillation in patients with left bundle branch block.

BACKGROUND: Left bundle branch block (LBBB) and atrial fibrillation (AF) are commonly coexisting conditions. The impact of LBBB on catheter ablation of AF has not been well determined. This study aims to explore the long-term outcomes of patients with AF and LBBB after catheter ablation. METHODS: Forty-two patients with LBBB of 11,752 patients who underwent catheter ablation of AF from 2011 to 2020 were enrolled as LBBB group. After propensity score matching in a 1:4 ratio, 168 AF patients without LBBB were enrolled as non-LBBB group. Late recurrence and a composite endpoint of stroke, all-cause mortality, and cardiovascular hospitalization were compared between the two groups. RESULTS: Late recurrence rate was significantly higher in the LBBB group than that in the non-LBBB group (54.8% vs. 31.5%, p = .034). Multivariate analysis showed that LBBB was an independent risk factor for late recurrence after catheter ablation of AF (hazard ratio [HR] 2.19, 95% confidence interval [CI] 1.09-4.40, p = .031). LBBB group was also associated with a significantly higher incidence of the composite endpoint (21.4% vs. 6.5%, HR 3.98, 95% CI 1.64-9.64, p = .002). CONCLUSIONS: LBBB was associated with a higher risk for late recurrence and a higher incidence of composite endpoint in the patients underwent catheter ablation.

Prospective randomized comparison between upgraded '2C3L' vs. PVI approach for catheter ablation of persistent atrial fibrillation: PROMPT-AF trial design.

BACKGROUND: In randomized studies, the strategy of pulmonary vein antral isolation (PVI) plus linear ablation has failed to increase success rates for persistent atrial fibrillation (PeAF) ablation when compared with PVI alone. Peri-mitral reentry related atrial tachycardia due to incomplete linear block is an important cause of clinical failures of a first ablation procedure. Ethanol infusion (EI) into the vein of Marshall (EI-VOM) has been demonstrated to facilitate a durable mitral isthmus linear lesion. OBJECTIVE: This trial is designed to compare arrhythmia-free survival between PVI and an ablation strategy termed upgraded '2C3L' for the ablation of PeAF. STUDY DESIGN: The PROMPT-AF study (clinicaltrials.gov 04497376) is a prospective, multicenter, open-label, randomized trial using a 1:1 parallel-control approach. Patients (n = 498) undergoing their first catheter ablation of PeAF will be randomized to either the upgraded '2C3L' arm or PVI arm in a 1:1 fashion. The upgraded '2C3L' technique is a fixed ablation approach consisting of EI-VOM, bilateral circumferential PVI, and 3 linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavotricuspid isthmus. The follow-up duration is 12 months. The primary end point is freedom from atrial arrhythmias of >30 seconds, without antiarrhythmic drugs, in 12 months after the index ablation procedure (excluding a blanking period of 3 months). CONCLUSIONS: The PROMPT-AF study will evaluate the efficacy of the fixed '2C3L' approach in conjunction with EI-VOM, compared with PVI alone, in patients with PeAF undergoing de novo ablation.

Risk Factors for Left Ventricular Thrombus Formation in Patients with Dilated Cardiomyopathy.

BACKGROUND: Left ventricular thrombus (LVT) is a common complication of dilated cardiomyopathy (DCM), causing morbidity and mortality. METHODS: This study retrospectively analyzed patients with DCM from January 2002 to August 2020 in Beijing Anzhen Hospital. Clinical characteristics were compared between the LVT group and the age and sex 1:4 matched with the LVT absent group. The receiver operator characteristic (ROC) curve was plotted to evaluate the diagnostic value of D-dimer predicting LVT occurrence in DCM. RESULTS: A total of 3,134 patients were screened, and LVT was detected in 72 (2.3%) patients on echocardiography. The patients with LVT had higher D-dimer, fibrinogen, and lower systolic blood pressure than those without LVT. The ejection fraction (EF) was lower and left ventricular end-systolic diameter was larger in the LVT group. Severe mitral regurgitation (MR) was more common in the LVT absent groups. The prevalence of atrial fibrillation was lower in the LVT group. The ROC curve analysis yielded an optimal cut-off value of 444 ng/mL DDU (D-dimer units) for D-dimer to predict the presence of LVT. Multivariable binary logistic regression analysis revealed that EF (OR = 0.90, 95% CI = 0.86-0.95), severe MR (OR = 0.19, 95% CI = 0.08-0.48), and D-dimer level (OR = 15.4, 95% CI = 7.58-31.4) were independently associated with LVT formation. CONCLUSION: This study suggested that elevated D-dimer levels (>444 ng/mL DDU) and reduced EF were independently associated with increased risk of LVT formation. Severe MR could decrease the incidence of LVT.

Direct autotransfusion in the management of acute pericardial tamponade during catheter ablation for atrial fibrillation: An imperfect but practical method.

Background: Acute pericardial tamponade (APT) is one of the most serious complications of catheter ablation for atrial fibrillation (AF-CA). Direct autotransfusion (DAT) is a method of reinjecting pericardial blood directly into patients through vein access without a cell-salvage system. Data regarding DAT for APT are rare and provide limited information. Our present study aims to further investigate the safety and feasibility of DAT in the management of APT during the AF-CA procedure. Methods and results: We retrospectively reviewed 73 cases of APT in the perioperative period of AF-CA from January 2014 to October 2021 at our institution, among whom 46 were treated with DAT. All included patients successfully received emergency pericardiocentesis through subxiphoid access guided by X-ray. Larger volumes of aspirated pericardial blood (658.4 ± 545.2 vs. 521.2 ± 464.9 ml), higher rates of bridging anticoagulation (67.4 vs. 37.0%), and surgical repair (6 vs. 0) were observed in patients with DAT than without. Moreover, patients with DAT were less likely to complete AF-CA procedures (32/46 vs. 25/27) and had a lower incidence of APT first presented in the ward (delayed presentation) (8/46 vs. 9/27). There was no difference in major adverse events (death/disseminated intravascular coagulation/multiple organ dysfunction syndrome and clinical thrombosis) (0/0/1/0 vs. 1/0/0/0), other potential DAT-related complications (fever/infection and deep venous thrombosis) (8/5/2 vs. 5/3/1), and length of hospital stay (11.4 ± 11.6 vs. 8.3 ± 4.7 d) between two groups. Conclusion: DAT could be a feasible and safe method to deal with APT during AF-CA procedure.

Repeat ablation strategy for recurrent persistent atrial fibrillation: A propensity-matched score comparison between "2C3L" and "extensive ablation" approach.

BACKGROUND: Debates exist in the repeat ablation strategy for patients with recurrence presenting as persistent atrial fibrillation (AF) after initial persistent AF ablation. OBJECTIVE: To compare the outcome between the "2C3L" and "extensive ablation" approach in patients undergoing repeat procedures for recurrent persistent AF. METHODS: Propensity-score matching was performed in 196 patients with AF recurrence undergoing repeat ablation, and 79 patients treated with "2C3L" strategy were matched to 79 patients treated with "extensive ablation" strategy. The "2C3L" approach included pulmonary vein isolation, mitral isthmus, left atrial roof, and cavotricuspid isthmus ablation, while the "extensive ablation" strategy included extensive ablation of a variety of other targets aiming to terminate the AF. The primary outcome was freedom from any atrial tachyarrhythmia after 24-h ambulatory monitoring follow-up for 12 months. RESULTS: No statistically significant difference was found between the primary outcome between the "2C3L" and the "extensive ablation" group [70.9% vs. 69.6%, p = .862; 95% confidence interval (CI) -12.8 to 15.3], although the "extensive ablation" group had a significantly high proportion of AF termination (19.0% for "2C3L" vs. 41.8% for "extensive ablation" group, p = .002; 95% CI 8.5-35.9). And AF termination was not related to the primary outcome in multifactorial regression. At 40 ± 22 months after the repeat procedure, the primary outcome was also comparable (57.0 % for "2C3L" vs. 48.1% for "extensive ablation" group, p = .265; 95% CI -6.6 to 23.7). CONCLUSION: The outcome between the "2C3L" and "extensive ablation" approaches was comparable in patients undergoing repeat procedures for recurrent persistent AF.

Outcome of catheter ablation for paroxysmal atrial fibrillation in patients with stable coronary artery disease.

BACKGROUND: Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. This study aimed to assess the long-term outcome of catheter ablation in patients with paroxysmal AF and SCAD. METHODS: In total, 12,104 patients with paroxysmal AF underwent catheter ablation in the Chinese Atrial Fibrillation Registry between 2011 and 2019 were screened. A total of 441 patients with SCAD were matched with patients without SCAD in a 1:4 ratio. The primary endpoint was AF recurrence after single ablation. The composite secondary endpoints were thromboembolism, coronary events, major bleeding, all-cause death. RESULTS: Over a mean follow-up of 46.0 ± 18.9 months, the recurrence rate in patients with SCAD was significantly higher after a single ablation (49.0% vs. 41.9%, p = .03). The very late recurrence rate of AF in the SCAD group was also significantly higher than that in the control group (38.9% vs. 31.2%;p = .04). In multivariate analysis, adjusted with the female, smoking, duration of AF, previous thromboembolism, COPD, and statins, SCAD was independently associated with AF recurrence (adjusted HR, 1.19 [1.02-1.40], p = .03). The composite secondary endpoints were significantly higher in the SCAD group (12.70% vs. 8.54%, p = .02), mainly due to thromboembolism events (8.16% vs. 4.41%, p < .01). CONCLUSIONS: SCAD significantly increased the risk of recurrence after catheter ablation of paroxysmal AF. The incidence of thromboembolic events after catheter ablation of paroxysmal AF in the patients with SCAD was significantly higher than that in those without SCAD.

Impact of Low-density Lipoprotein Cholesterol Levels on Outcomes in Nonvalvular Atrial Fibrillation: Results from the China Atrial Fibrillation Registry Study.

BACKGROUND Low-density lipoprotein cholesterol (LDL-C) reduction improves cardiovascular outcomes. This study investigates the relationship between lipid levels and outcomes in patients with nonvalvular atrial fibrillation by LDL-C quarters. MATERIAL AND METHODS Patients with atrial fibrillation were enrolled from 31 typical hospitals in China. Of 19 515 patients, 6775 with nonvalvular atrial fibrillation (NVAF) were followed for 5 years or until an event occurred. RESULTS Hyperlipidemia was not an independent risk factor for stroke/thromboembolism and cardiovascular mortality among patients with NVAF (hazard ratio 0.82, 95% CI 0.7-0.96, P=0.82). When patients were divided into quartiles according to LDL-C levels at the time of enrollment (Q1, <1.95; Q2, 1.95-2.51; Q3, 2.52-3.09; and Q4, >3.09 mmol/L), as LDL-C increased, events tapered off according to Kaplan-Meier curves for patients who were without oral anticoagulants and off statins (non-OAC; log-rank=8.3494, P=0.0393) and for those with oral anticoagulants (OAC; log-rank=6.7668 P=0.0797). This relationship was stronger for patients who were without OAC treatment and off statins than for those with OAC treatment. The relationship was not significant in patients with or without OAC and on statins (log-rank=2.5080, P=0.4738). This relationship also existed in patients with CHA2DS2-VASc scores <2 (log-rank=5.893, P=0.1167). For those with CHA2DS2-VASc scores ≥2 (log-rank=6.6163, P=0.0852), the relationship was stronger. CONCLUSIONS In patients with NVAF using standard or no lipid-lowering medication, low plasma LDL-C levels were related to an increased risk of stroke/thromboembolism and cardiovascular mortality.

A strategy of idarucizumab for pericardial tamponade during perioperative period of atrial fibrillation ablation.

OBJECTIVE: To investigate theoptimal idarucizumab (dabigatran antagonist) usage strategy for patients with acute pericardial tamponade receiving uninterrupted dabigatran during catheter ablation for atrial fibrillation (AF). METHODS: Ten patients presenting acute pericardial tamponade while receiving uninterrupted dabigatran during catheter ablation for AF in Beijing Anzhen Hospital from January 2019 to July 2020 were enrolled and retrospectively analyzed. A "wait and see" strategy of idarucizumab was carried out for all patients; in brief, idarucizumab was applied following pericardiocentesis, comprehensive evaluation of bleeding and hemostasis. RESULTS: There were five males, five paroxysmal AF, and the average age of the patients was 64.0 ± 9.8 years. Among the 10 patients, four were treated with dabigatran 110 mg, six were treated with dabigatran 150 mg, and one was simultaneously given clopidogrel. The average time from pericardial tamponade to the last dose of dabigatran was 8.2 ± 3.4 h. All patients underwent pericardiocentesis successfully, and the average drainage volume was 322.5 ml (220.0 ± 935.0 ml). For reversal anticoagulation, six patients received protamine, and five patients received idarucizumab. Of the five patients who were treated with idarucizumab, four presented exact hemostasis, except for one patient who underwent continuous drainage and finally received surgery repair. The average time to restart anticoagulation was 1.1 ± 0.3 days after the procedure, and no rebleeding, embolism or deaths were observed. CONCLUSION: The "wait and see" strategy of idarucizumab for acute pericardial tamponade during the perioperative period of catheter ablation for AF may be safe and feasible.

Comparison of prognosis and outcomes of catheter ablation versus drug therapy in patients with atrial fibrillation and stable coronary artery disease: A prospective propensity-score matched cohort study.

BACKGROUND: Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. HYPOTHESIS: To investigate the prognosis of catheter ablation versus drug therapy in patients with AF and SCAD. METHODS: In total, 25 512 patients with AF in the Chinese AF Registry between 2011 and 2019 were screened for SCAD. 815 patients with AF and SCAD underwent catheter ablation therapy were matched with patients by drug therapy in a 1:1 ratio. Primary end point was composite of thromboembolism, coronary events, major bleeding, and all-cause death. The secondary endpoints were each component of the primary endpoint and AF recurrence. RESULTS: Over a median follow-up of 45 ± 23 months, the patients in the catheter ablation group had a higher AF recurrence-free rate (53.50% vs. 18.41%, p < .01). In multivariate analysis, there was no significant difference between the strategy of catheter ablation and drug therapy in primary composite end point (adjusted HR 074, 95%CI 0.54-1.002, p = .0519). However, catheter ablation was associated with fewer all-cause death independently (adjusted HR 0.36, 95%CI 0.22-0.59, p < .01). In subgroup analysis, catheter ablation was an independent risk factor for all-cause death in the high-stroke risk group (adjusted HR 0.39, 95%CI 0.23-0.64, p < .01), not in the low-medium risk group (adjusted HR 0.17, 95%CI 0.01-2.04, p = .17). CONCLUSIONS: In the patients with AF and SCAD, catheter ablation was not independently associated with the primary composite endpoint compared with drug therapy. However, catheter ablation was an independent protective factor of all-cause death.

Healthcare quality and mortality among patients hospitalized for heart failure by hospital level in Beijing, China.

AIMS: This study sought to compare healthcare quality and 30 day, 90 day, and 1 year mortality rates among patients admitted to secondary and tertiary hospitals for heart failure (HF) in Beijing. METHODS AND RESULTS: This study retrospectively enrolled patients hospitalized with a primary discharge diagnosis of HF during January 2014 to December 2015, from five tertiary and four secondary hospitals, in Beijing, China. Mortality data were extracted from Beijing Death Surveillance Database. HF healthcare quality indices were used to evaluate in-hospital care. Associations between hospital level and mortality rates were assessed using generalized linear mixed models, adjusting for patients' baseline characteristics and intra-hospital correlation. Data from 1413 patients (median [interquartile range] age = 74 [65-80] years, 52.7% female) from secondary hospitals and 1250 patients (median [interquartile range] age = 72 [61-79] years, 43.3% female) from tertiary hospitals were collected. Rates of left ventricular ejection fraction assessment (73.2% vs. 90.1%) and combined use of ß-blockers and angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (30.1% vs. 49.3%) were lower in secondary hospitals than those in tertiary hospitals, respectively. Patients admitted to secondary hospitals had a higher 90 day mortality [10.8% vs. 5.0%; adjusted odds ratio (OR): 2.06; 95% confidence interval (CI): 1.10-3.84, P = 0.024 and a higher 1 year mortality rate [21.0% vs. 12.1%; adjusted OR: 1.64; 95% CI: 1.02-2.62, P = 0.039], but 30 day mortality rates were not significantly different (5.5% vs. 3.0%; adjusted OR: 1.49; 95% CI: 0.63-3.52, P = 0.368). CONCLUSIONS: Worse quality of care for patients with HF in secondary hospitals was associated with higher 90 day and 1 year mortality rates. Improving care quality in secondary hospitals is crucial to improve prognosis of patients they served.

Catheter ablation of atrial fibrillation in situs inversus dextrocardia: Challenge, improved procedure, outcomes, and literature review.

INTRODUCTION: Catheter ablation for atrial fibrillation (AF-CA) in patients with situs inversus dextrocardia (SID) can be challenging because of the contrary anatomy and associated anomalies. Cases and literature regarding AF-CA in SID are rare and provide little information. Our study aims to present an improved procedure, ablation strategies, and evaluate the safety and outcomes of AF-CA in patients with AF and SID. METHODS: A total of 10 patients with AF-SID (mean age, 60.4 ± 15.7 years; six paroxysmal AF, four persistent atrial fibrillation [PeAF]) were enrolled. For the improved procedure, images obtained by preacquired computed tomography and three-dimensional electroanatomical mapping, integrating intracardiac echocardiography, and x-ray imaging data are necessary to optimize the transseptal puncture and ablation procedure. RESULTS: All patients successfully underwent 13 AF-CA procedures without complications, including three patients received repeat procedures. However, two PeAF patients presented sick sinus syndrome (SSS) after the AF-CA procedure, and one underwent permanent pacemaker implantation therapy during hospitalization. During the follow-up period (6-72 months), the outcomes were not favorable: three patients (30%) maintained sinus rhythm (SR) after the initial procedure; after repeated procedures, the overall SR rate was 40% (four patients). CONCLUSION: With the improved strategy, AF-CA can be safely and effectively performed with low radiation exposure in patients with SID. However, the long-term outcomes were not favorable, even when managed at a tertiary center by a team of specialists. Moreover, patients with PeAF might also have masked SSS, which should be carefully considered.

New-Onset Atrial Fibrillation and Adverse In-Hospital Outcome in Patients with Acute Pulmonary Embolism.

Atrial fibrillation (AF) can be secondary to acute pulmonary embolism (PE). This study aimed to investigate the prognostic impact of new-onset AF on patients with acute PE. In this study, 4,288 consecutive patients who were diagnosed with acute PE were retrospectively screened. In total, 77 patients with acute PE and new-onset AF were analyzed. Another 154 acute PE patients without AF were selected as the age- and sex-matched control group. Adverse in-hospital outcome comprised one of the following conditions: all-cause death, endotracheal intubation, cardiopulmonary resuscitation, and intravenous catecholamine therapy. The patients with new-onset AF had higher prevalence of congestive heart failure, higher simplified PE severity index (sPESI), higher creatinine, and larger left atrium diameter. The incidences of adverse in-hospital outcomes were 10.4 and 2.6% in patients with new-onset AF and no AF, respectively (p = 0.02). Patients with sPESI ≥ 1 had higher incidence of adverse in-hospital outcomes than those with sPESI = 0 (9.4 vs. 0.9%, p < 0.01). The area under the receiver operating characteristic curve of sPESI and sPESI + AF (adding 1 point for new-onset AF) scores in assessing the adverse in-hospital outcome were 0.80 (95% confidence interval [CI]: 0.68-0.93) and 0.84 (95% CI: 0.72-0.96), respectively. In multivariable analysis, sPESI ≥ 1 (odds ratio, 8.88; 95% CI: 1.10-72.07; p = 0.04) was an independent predictor of adverse in-hospital outcome. However, new-onset AF was not an independent predictor. In the population studied, sPESI is an independent predictor of adverse in-hospital outcomes, whereas new-onset AF following acute PE is not, but it may add predictive value to sPESI.

Safety and efficacy of catheter ablation for atrial fibrillation in abdominal solid organ (renal and hepatic) transplant recipients: A single-center pilot experience.

BACKGROUND: Atrial fibrillation (AF) is common in abdominal solid organ transplant recipients and a cause of morbidity and mortality in this population. However, the outcomes of catheter ablation (CA) in transplant recipients with AF remain unclear. This study aimed to elucidate the outcomes of CA in renal and hepatic transplant recipients. METHODS AND RESULTS: Between 2015 and 2019, 14 transplant recipients (nine with kidney transplantation and five with liver transplantation) were enrolled from among 10,741 AF patients and underwent CA at Anzhen Hospital. Another 56 patients matched by age, sex, and AF type were selected as the control group (four controls for each transplant recipient). During a mean follow-up of 30.0 ± 13.3 months after the initial procedure, 10 (71.4%) of the transplant patients, compared to 41 (73.2%) of the control patients, remained free from AF recurrence (p = 1.000). A repeated procedure was performed in one transplant patient and in six control subjects. Consequently, 11 (78.6%) of the transplant patients, compared to 46 (82.1%) of controls, were in sinus rhythm after the repeated ablation (p = .715). Notably, Kaplan-Meier analysis did not demonstrate any significant differences in the atrial arrhythmia-free rate after the initial and repeated procedure between the two groups. Vascular complications were identified in one transplant patient and two control subjects, while no life-threatening complications were observed in either group. There was no transient allograft dysfunction in transplant recipients after CA. CONCLUSION: CA is safe and effective in abdominal solid transplant recipients, and maybe an optimal therapeutic strategy for this group.

Relationship Between Ablation Lesion Size Estimated by Ablation Index and Different Ablation Settings-an Ex Vivo Porcine Heart Study.

This study aimed to verify the reliability of ablation index (AI) for ablation lesion estimating with different settings for radiofrequency (RF) parameters: power, impedance, contact angles, irrigation rate, temperature of irrigation saline, and irrigation solution. RF ablations (N = 66) were performed on ex vivo porcine left ventricle submerged in 37 °C saline. The aforementioned ablation parameters were changed to measure whether the size of the ablation lesion was consistent at a fixed AI value of 500. The maximum lesion diameter (r = - 0.631, P = 0.028), depth (r = - 0.896, P < 0.001), and volume (r = - 0.745, P < 0.005) were significantly reduced with an increase of the impedance. The lesion depth (P < 0.05) and the lesion volume (P < 0.05) were significantly larger with glucose irrigation than saline irrigation. In conclusion, at a fixed AI value, impedance and irrigation solution have impact on the ablation lesions, which could affect the accuracy of AI formula to estimate ablation lesion size. Graphical abstract.

Crosstalk between PKC and MAPK pathway activation in cardiac fibroblasts in a rat model of atrial fibrillation.

OBJECTIVE: Atrial fibrillation (AF) is the most frequent form of cardiac arrhythmia and major cause of cardiac ischemia. Defective calcium homeostasis due to anomalous expression of ryanodine receptor type 2 (RyR2) or its hyperactivation by phosphorylation by serine threonine kinases has been implicated as a central mechanism of AF pathogenesis. Given the role of protein kinase C (PKC) isoforms in cardiac function we investigated role of PKC in AF using a rat model. RESULTS: PMA induced global increase in protein synthesis in cardiac fibroblasts isolated from AF rats, but not healthy controls, and the increase was inhibited by PKC inhibition. PMA mediated activation of both PKC and ERK and either inhibition of PKC by Go6983 or ERK by the MEK inhibitor Trametinib attenuated both P-ERK and P-PKC in both cardiac fibroblasts isolated from AF rats or from healthy rats but transduced with PKC-delta. The PKC and ERK mediated induction of global protein synthesis was found to be mediated by increased phosphorylation of the ribosomal protein S6. CONCLUSION: Our findings provide a foundation for future testing of PKC and MEK inhibitors to treat AF in pre-clinical models. It also needs to be determined if PKC and MAPK pathway activation is functioning via RyR2 or some yet undefined substrates.

Zero-fluoroscopy approach for ablation of supraventricular tachycardia using the Ensite NavX system: a multicenter experience.

BACKGROUND: Three-dimensional electroanatomic mapping systems have demonstrated a significant reduction in radiation exposure during radiofrequency catheter ablation procedures. We aimed to investigate the safety, feasibility and efficacy of a completely zero-fluoroscopy approach for catheter ablation of supraventricular tachycardia using the Ensite NavX navigation system compared with a conventional fluoroscopy approach. METHODS: A multicenter prospective non-randomized registry study was performed in seven centers from January 2013 to February 2018. Consecutive patients referred for catheter ablation of supraventricular tachycardia were assigned either to a completely zero-fluoroscopic approach (ZF) or conventional fluoroscopy approach (CF) according to the operator's preference. Patients with atrial tachycardia were excluded. RESULTS: Totally, 1020 patients were enrolled in ZF group; 2040 patients ablated by CF approach were selected for controls. There was no significant difference between the zero-fluoroscopy group and conventional fluoroscopy group as to procedure time (60.3 ± 20.3 vs. 59.7 ± 22.6 min, P = 0.90), immediate success rate of procedure (98.8% vs. 99.2%, P = 0.22), arrhythmia recurrence (0.4% vs. 0.5%, P = 0.85), total success rate of procedure (98.4% vs. 98.8%, P = 0.39) or complications (1.1% vs. 1.5%, P = 0.41). Compared with the conventional fluoroscopy approach, the zero-fluoroscopy approach provided similar outcomes without compromising the safety or efficacy of the procedure. CONCLUSION: The completely zero-fluoroscopy approach demonstrated safety and efficacy comparable to a conventional fluoroscopy approach for catheter ablation of supraventricular tachycardia, and mitigated radiation exposure to both patients and operators. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT03042078; first registered February 3, 2017; retrospectively registered.

The safety of discontinuation of oral anticoagulation therapy after apparently successful atrial fibrillation ablation: a report from the Chinese Atrial Fibrillation Registry study.

AIMS: We aimed to investigate the safety of discontinuing oral anticoagulation (OAC) therapy after apparently successful atrial fibrillation (AF) ablation, using data from the Chinese Atrial Fibrillation Registry study. METHODS AND RESULTS: We identified 4512 consecutive patients who underwent successful AF ablation between August 2011 and December 2017. Of them, 3149 discontinued OAC 3 months post-ablation (Off-OAC group) and 1363 continued OAC beyond this period (On-OAC group). Regular follow-up examinations were undertaken to detect AF recurrence, monitor OAC therapy, and measure clinical outcomes. Primary outcomes included thromboembolic and major bleeding (MB) events experienced beyond 3 months after ablation. Low thromboembolic and MB event rates were noted in the on-treatment analysis. The incidence rates for thromboembolism were 0.54 [95% confidence interval (CI) 0.39-0.76] and 0.86 (95% CI 0.56-1.30) per 100 patient-years, and that for MB events were 0.19 (95% CI 0.11-0.34) and 0.35 (95% CI 0.18-0.67) per 100 patient-years, for the Off-OAC and On-OAC groups over mean follow-up periods of 24.2 ± 14.7 and 23.0 ± 13.6 months, respectively. Similar results were observed in the intention-to-treat analysis. Previous history of ischaemic stroke (IS)/transient ischaemic attack (TIA)/systemic embolism (SE) [hazard ratio (HR) 3.40, 95% CI 1.92-6.02; P < 0.01] and diabetes mellitus (HR 2.06, 95% CI 1.20-3.55, P = 0.01) were independently associated with thromboembolic events, while OAC discontinuation (HR 0.71, 95% CI 0.41-1.23, P = 0.21) remained insignificant in multivariable analysis. CONCLUSIONS: This study suggests that it may be safe to discontinue OAC in post-ablation patients under diligent monitoring, in the absence of AF recurrence, history of IS/TIA/SE, and diabetes mellitus. However, further large-scale randomized trials are required to confirm this. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-OCH-13003729. URL: http://www.chictr.org.cn/showproj.aspx?proj=5831.

Prevalence of modifiable risk factors and relation to stroke and death in patients with atrial fibrillation: A report from the China atrial fibrillation registry study.

BACKGROUND: Lifestyle and risk factor management may improve outcomes in patients with atrial fibrillation (AF). We aim to evaluate the prevalence of modifiable risk factors and how these factors impact clinical outcomes in patients with AF. METHODS AND RESULTS: Data on 17 898 AF cohort patients with AF enrolled between 2011 and 2016 was analyzed. A healthy lifestyle was defined as not smoking, not drinking, a healthy body mass index (BMI), untreated total cholesterol less than 200 mg/dL, untreated blood pressure (BP) less than 120/80 mm Hg, and untreated fasting plasma glucose (FPG) less than 100 mg/dL. The association between risk factors and risk of the composite endpoint of all-cause mortality and nonfatal ischemic stroke were assessed using Cox proportional hazards regression model. Only 4.0% of patients achieved a healthy lifestyle. In multivariate analysis, current smoking, a low BMI, not well-controlled FPG were independently and significantly associated with higher risk of all-cause mortality and nonfatal ischemic stroke, with corresponding hazard ratio (HR) estimates 1.22 (95% confidence interval [CI], 1.00-1.47), HR = 1.72 (95% CI, 1.34-2.20), and HR = 1.25 (95% CI, 1.06-1.46), respectively. High BP was also associated with higher risk with the outcomes (HR = 1.15, 95% CI, 1.00-1.34). Compared with patients with no risk factor, those who failed to maintained or achieved optimal risk factor control had a progressively higher risk of death and nonfatal ischemic stroke (HR for 1 risk factor = 1.44; 95% CI, 1.07-1.92; and more than 2 risk factors = 1.75; 95% CI, 0.99-3.09). CONCLUSIONS: Maintenance of well-controlled risk factors may substantially lower the risk of death and ischemic stroke in patients with AF.

Depolarization and repolarization parameters on ECG predict recurrence after atrial fibrillation ablation in patients with hypertrophic cardiomyopathy.

INTRODUCTION: The outcomes of atrial fibrillation (AF) ablation remain suboptimal. It is important to identify which AF patients will most likely benefit from ablation and who are more likely to show treatment failure, especially in those with structural heart disease such as hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: We enrolled 120 HCM patients who underwent primary AF ablation (48 with persistent AF). Preprocedural QTc was measured and corrected using the Bazett's formula, and the distribution of fragmentation of the QRS complex (fQRS) was recorded. Arrhythmia recurrence was defined as any kind of documented atrial tachyarrhythmia of more than 30 seconds. Overall, arrhythmia recurrence occurred in 69 patients after 13.4 months' follow-up. fQRS was present in 71 (59.17%) patients and was most commonly (81.69%) observed in the inferior leads. QTc more than 448 ms could predict arrhythmia recurrence with a sensitivity of 68.1% and specificity of 68.6%. Patients with QTc more than 448 ms (hazard ratio [HR]: 1.982; 95% confidence interval [CI]: 1.155-3.402; P = .013) or those with fQRS+ (HR: 1.922; 95% CI: 1.151-3.210; P = .012) were at an increased risk of recurrence. A combination of fQRS+ and QTc more than 448 ms was superior to fQRS or QTc alone in predicting arrhythmia recurrence. CONCLUSION: In patients with HCM undergoing AF ablation, QTc prolongation, specifically >448 ms, and presence of fQRS are independent risk factors for arrhythmia recurrence at follow-up. The combination of these two parameters has greater predictive value and would help to identify patients who are at the highest risk of procedural failure.

Serum potassium levels and mortality of patients with acute myocardial infarction: A systematic review and meta-analysis of cohort studies.

BACKGROUND: The evidence of current epidemiological studies investigating the association between serum potassium levels and mortality of acute myocardial infarction (AMI) patients is controversial and inadequate. DESIGN: Systematic review and meta-analysis. METHODS: Two researchers independently searched the PubMed, EMBASE and Web of Science databases to identify observational studies published prior to 31 October 2017. Similarly, two researchers separately extracted data and any differences were resolved by discussion. Pooled relative risks and 95% confidence intervals (CIs) were computed with an inverse variance-weighted random-effects model. Heterogeneity among studies was assessed with the I2 statistic. RESULTS: Seven cohort studies were included for analysis. Compared with the reference group (3.5 to <4.0 mEq/L), the pooled relative risks of mortality were 1.15 (95% CI = 1.00-1.32), 1.09 (95% CI = 0.97-1.24), 1.42 (95% CI = 1.19-1.70) and 1.85 (95% CI = 1.39-2.47) for AMI patients with a potassium level of<3.5, 4.0 to <4.5, 4.5 to <5.0, and ≥5.0 mEq/L, respectively. For admission and post-admission potassium, although J-shaped associations were also indicated, non-significant results were observed for AMI patients with potassium levels of <3.5 mEq/L when compared with the reference group. Notably, in subgroup analyses of study characteristics, stratified by study quality, geographic location, type of outcome, number of cases, type of AMI, and adjustment for potential confounders, the findings were broadly consistent across strata. CONCLUSIONS: These findings indicate that both lower (<3.5 mEq/L) and higher (≥4.5 mEq/L) serum potassium levels are associated with an increased risk of mortality of patients with AMI.