Lower rate of major bleeding in very high risk patients undergoing left atrial appendage occlusion: A propensity score-matched comparison with direct oral anticoagulant.

BACKGROUND: Long-term oral anticoagulation is the mainstay therapy for thromboembolic (TE) prevention in patients with atrial fibrillation. However, left atrial appendage occlusion (LAAO) could be a safe alternative to direct oral anticoagulants (DOACs) in patients with a very high TE risk profile. OBJECTIVE: The purpose of this study was to compare the safety and efficacy of LAAO vs DOACs in patients with atrial fibrillation at very high stroke risk (CHA2DS2-VASc [congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category] score ≥ 5). METHODS: Data from patients with CHA2DS2-VASc score ≥ 5 were extracted from a prospective multicenter database. To attenuate the imbalance in covariates between groups, propensity score matching was used (covariates: CHA2DS2-VASc and HAS-BLED [hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol] scores), which resulted in a matched population of 277 patients per group. The primary end point was a composite of cardiovascular death, TE events, and clinically relevant bleeding during follow-up. RESULTS: Of 2381 patients, 554 very high risk patients were included in the study (mean age 79 ± 7 years; CHA2DS2-VASc score 5.8 ± 0.9; HAS-BLED score 3.0 ± 0.9). The mean follow-up duration was 25 ± 11 months. A higher incidence of the composite end point was documented with DOACs compared with LAAO (14.9 events per 100 patient-years in the DOAC group vs 9.4 events per 100 patient-years in the LAAO group; P = .03). The annualized clinically relevant bleeding risk was higher with DOACs (6.3% vs 3.2%; P = .04), while the risk of TE events was not different between groups (4.1% vs 3.2%; P = .63). CONCLUSION: In high-risk patients, LAAO had a similar stroke prevention efficacy but a significantly lower risk of clinically relevant bleeding when compared with DOACs. The clinical benefit of LAAO became significant after 18 months of follow-up.

Transesophageal Echocardiography Following Left Atrial Appendage Electrical Isolation: Diagnostic Pitfalls and Clinical Implications.

BACKGROUND: Following left atrial appendage (LAA) electrical isolation, the decision on whether to continue oral anticoagulation after successful atrial fibrillation ablation is based on the study of its mechanical function on transesophageal echocardiography (TEE). In this cohort, LAA contraction is absent and the incorrect interpretation of emptying flow velocities can lead to unwanted clinical sequelae. METHODS: One hundred and sixty consecutive TEE exams performed to evaluate the LAA mechanical function following its electrical isolation were reviewed by an experienced operator blinded to the original diagnosis of LAA dysfunction. The rate of diagnostic discrepancy in the assessment LAA dysfunction and its clinical implications were evaluated. RESULTS: Diagnostic discrepancy with misclassification of the LAA mechanical function occurred 36% (58/160) of TEE exams. In most cases (57/58), such discrepancy was observed in the setting of an incorrect original diagnosis of a normal LAA mechanical function despite absent/reduced or inconsistent LAA contraction. This main source of this wrong diagnosis was the wrong interpretation of passive LAA flows (34/57; 60%), followed by failure to identify dissociated firing (15/57; 26%). In rare cases (8/57; 14%), velocities of surrounding structures were interpreted as LAA flow due to misplacement of the pulsed-wave Doppler sample volume. Following LAA isolation, the proportion of patients who experienced a cerebrovascular event while off oral anticoagulation due to the misclassification of their LAA mechanical function was 70% (7/10 [95% CI, 40%-89%]). CONCLUSIONS: Underdiagnosis of LAA mechanical dysfunction is common in TEEs performed following LAA electrical isolation, and it is associated with an increased risk of cerebrovascular events owing to oral anticoagulation discontinuation despite absent/reduced LAA contraction. Careful review of the TEE exam by an operator with specific expertise in LAA imaging and familiar with the functional implications of LAA isolation is necessary before interrupting oral anticoagulation in this cohort.

Prevalence, Management, and Outcome of Atrial Fibrillation and Other Supraventricular Arrhythmias in COVID-19 Patients.

COVID-19 mainly affects the respiratory system but has been correlated with cardiovascular manifestations such as myocarditis, heart failure, acute coronary syndromes, and arrhythmias. Cardiac arrhythmias are the second most frequent complication affecting about 30% of patients. Several mechanisms may lead to an increased risk of cardiac arrhythmias during COVID-19 infection, ranging from direct myocardial damage to extracardiac involvement. The aim of this review is to describe the role of COVID-19 in the pathogenesis of cardiac arrhythmias and provide a comprehensive guidance for their monitoring and management.

RETRACTED:B-PO04-095 ESOPHAGEAL TEMPERATURE MONITORING DURING ATRIAL FIBRILLATION ABLATION WITH THE PULSED FIELD ABLATION SYSTEM.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors. The authors inadvertently specified some ablation settings in the methods section that should not have been reported because they can be potentially linked to a specific pulsed field ablation technology that is currently under investigation for FDA approval. The Authors apologize for the inconvenience caused by this oversight, http://dx.doi.org/.

Half-Dose Direct Oral Anticoagulation Versus Standard Antithrombotic Therapy After Left Atrial Appendage Occlusion.

OBJECTIVES: This study evaluated the long-term efficacy of a standard antithrombotic strategy versus half-dose direct oral anticoagulation (DOAC) after Watchman implantation. BACKGROUND: No consensus currently exists on the selection of the most effective antithrombotic strategy to prevent device-related thrombosis (DRT) in patients undergoing endocardial left atrial appendage closure. METHODS: After successful left atrial appendage closure, consecutive patients were prescribed a standard antithrombotic strategy (SAT) or long-term half-dose DOAC (hdDOAC). The primary composite endpoint was DRT and thromboembolic (TE) and bleeding events. RESULTS: Overall, 555 patients (mean age 75 ± 8 years, 63% male; median CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category] score 4 [interquartile range (IQR): 3-6]; median HAS-BLED [hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol] score 3 [IQR: 2-4]) were included. Patients were categorized into 2 groups (SAT: n = 357 vs hdDOAC: n = 198). Baseline clinical characteristics were similar between groups. The median follow-up duration was 13 months (IQR: 12-15 months). DRT occurred in 12 (2.1%) patients, all in the SAT group (3.4% vs 0.0%; log-rank P = 0.009). The risk of nonprocedural major bleeding was significantly more favorable in the hdDOAC group (0.5% vs. 3.9%; log-rank P = 0.018). The rate of the primary composite endpoint of DRT and TE and major bleeding events was 9.5% in SAT patients and 1.0% in hdDOAC patients (HR: 9.8; 95% CI: 2.3-40.7; P = 0.002). CONCLUSIONS: After successful Watchman implantation, long-term half-dose DOAC significantly reduced the risk of the composite endpoint of DRT and TE and major bleeding events compared with a standard, antiplatelet-based, antithrombotic therapy.

Evaluation of a novel cardiac signal processing system for electrophysiology procedures: The PURE EP 2.0 study.

BACKGROUND: Intracardiac electrogram data remain one of the primary diagnostic inputs guiding complex ablation procedures. However, the technology to collect, process, and display intracardiac signals has known shortcomings and has not advanced in several decades. OBJECTIVE: The purpose of this study was to evaluate a new signal processing platform, the PURE EP™ system (PURE), in a multi-center, prospective study. METHODS: Intracardiac signal data of clinical interest were collected from 51 patients undergoing ablation procedures with PURE, the signal recording system, and the 3D mapping system at the same time stamps. The samples were randomized and subjected to blinded, controlled evaluation by three independent electrophysiologists to determine the overall quality and clinical utility of PURE signals when compared to conventional sources. Each reviewer assessed the same (92) signal sample sets and responded to (235) questions using a 10-point rating scale. If two or more reviewers rated the PURE signal higher than the control, it was deemed superior. RESULTS: A total of 93% of question responses showed consensus amongst the blinded reviewers. Based on the ratings for each pair of signals, a cumulative total of 164 PURE signals out of 218 (75.2%) were statistically rated as Superior for this data set (p < .001). Only 14 PURE signals out of 218 were rated as Inferior (6.4%). CONCLUSION: The PURE intracardiac signals were statistically rated as superior when compared to conventional systems.

Intracardiac echocardiography- versus transesophageal echocardiography-guided left atrial appendage occlusion with Watchman FLX.

INTRODUCTION: Watchman FLX has been recently approved for left atrial appendage occlusion (LAAO) in the US. Intracardiac echocardiography (ICE) - which is already commonly used to guide trans-septal access - can serve as an alternative to TEE, simplifying the procedure and reducing associated costs. Herein, we report our experience with ICE-guided LAAO with Watchman FLX. METHODS AND RESULTS: This cohort study included the first 190 consecutive patients who underwent LAAO with Watchman FLX in our center. LAAO was successful in all patients without significant peri-procedural, device-related complications in either group. Compared to TEE, we observed a significant reduction in procedural times when using ICE. In addition, there was a potentially clinically relevant reduction in fluoroscopy dose, mainly secondary to fewer cine acquisition runs. At follow-up, no cases of device embolism were noted, whereas the rate of device-related thrombosis and peri-device leaks were comparable between groups. CONCLUSION: ICE-guided LAAO with Watchman FLX is safe and feasible, with a significant reduction in procedural time and potential reduction in fluoroscopy dose when compared to TEE.

Incidence of Device-Related Thrombosis in Watchman Patients Undergoing a Genotype-Guided Antithrombotic Strategy.

OBJECTIVES: This study sought to report the incidence of device-related thrombosis (DRT) and thromboembolic (TE) events when an alternative to clopidogrel is prescribed in loss-of-function (LOF) allele carriers of the cytochrome P450 2C19 (CYP2C19) gene. BACKGROUND: LOF polymorphisms of the CYP2C19 gene are associated with reduced hepatic bioactivation of clopidogrel. METHODS: A total of 1,002 Watchman patients were included. Six hundred forty-five patients underwent CYP2C19 genetic testing; among patients with clopidogrel resistance, clopidogrel was replaced by either prasugrel (pilot cohort) or half dose direct oral anticoagulant ([DOAC]/Group 1), both in combination with aspirin. We compared the incidence of DRT/TE events among genotyped patients and a control group which received standard dual antiplatelet therapy (DAPT) (Group 2; n = 357). All reported events occurred during a timeframe between 45- and 180-day follow-up transesophageal echocardiograms, when the 2 different antithrombotic strategies (genotype-guided vs standard DAPT) were adopted. RESULTS: In the pilot cohort (n = 244), bleeding events occurred in 10.2% of patients who received aspirin plus prasugrel, leading to early discontinuation of the prasugrel-based protocol. DOAC Group 1 patients (n = 401), 25.7% were reduced metabolizers, and clopidogrel was replaced by half dose direct oral anticoagulant. DRT was documented in 1 (0.2%) patient of Group 1 and 7 (1.96%) patients of Group 2 (log-rank P = 0.021). The composite endpoint of DRT/TE events was significantly lower among patients receiving a genotype-guided antithrombotic strategy (0.75% vs 3.10%; log-rank P = 0.017). CONCLUSIONS: In Watchman patients, a genotype-based antithrombotic strategy with aspirin plus half dose DOAC in reduced clopidogrel metabolizers was superior to standard DAPT with respect to DRT/TE events.

Radiofrequency Energy Applications Targeting Significant Residual Leaks After Watchman Implantation: A Prospective, Multicenter Experience.

OBJECTIVES: The aim of this study was to evaluate the efficacy of radiofrequency (RF) energy applications targeting the atrial side of a significant residual leak in patients with acute and chronic evidence of incomplete percutaneous left atrial appendage (LAA) occlusion. BACKGROUND: RF applications have been proved to prevent recanalization of intracranial aneurysms after coil embolization, thereby favoring complete sealing. From a mechanistic standpoint, in vitro and in vivo experiments have demonstrated that RF promotes collagen deposition and tissue retraction. METHODS: Forty-three patients (mean age 75 ± 7 years mean CHA2DS2-VASc score 4.6 ± 1.4, mean HAS-BLED score 4.0 ± 1.1) with residual leaks ≥4 mm after Watchman implantation were enrolled. Procedural success was defined as complete LAA occlusion or presence of a mild or minimal (1- to 2-mm) peridevice leak on follow-up transesophageal echocardiography (TEE), which was performed approximately 45 days after the procedure. RESULTS: RF-based leak closure was performed acutely after Watchman implantation in 19 patients (44.2%) or scheduled after evidence of significant leaks on follow-up TEE in 24 others (55.8%). The median leak size was 5 mm (range: 4-7 mm). On average, 18 ± 7 RF applications per patient (mean maximum contact force 16 ± 3 g, mean power 44 ± 2 W, mean RF time 5.1 ± 2.5 minutes) were performed targeting the atrial edge of the leak. Post-RF median leak size was 0 mm (range: 0-1 mm). A very low rate (2.3% [n = 1]) of major periprocedural complications was observed. Follow-up TEE revealed complete LAA sealing in 23 patients (53.5%) and negligible residual leaks in 15 (34.9%). CONCLUSIONS: RF applications targeting the atrial edge of a significant peri-Watchman leak may promote LAA sealing via tissue remodeling, without increasing complications. (RF Applications for Residual LAA Leaks [REACT]; NCT04726943).

Amplatzer PFO Occluder for treatment of incomplete LAA closure with AtriClip.

Herein, we describe the use of an Amplatzer PFO Occluder to treat incomplete LAA closure due to a malpositioned AtriClip.

Real-Time 3D Intracardiac Echocardiography.

With real-time three-dimensional ultrasound, live volumetric images with adequate spatial and temporal resolution are obtained to accurately display structures with complex anatomy and guide interventional procedures. In this review, we will provide an overview of current ultrasound technologies that allow for real-time three-dimensional imaging, with a focus on their application for three-dimensional intracardiac echocardiography.

Natural History of Arrhythmia After Successful Isolation of Pulmonary Veins, Left Atrial Posterior Wall, and Superior Vena Cava in Patients With Paroxysmal Atrial Fibrillation: A Multi-Center Experience.

Background We evaluated long-term outcome of isolation of pulmonary veins, left atrial posterior wall, and superior vena cava, including time to recurrence and prevalent triggering foci at repeat ablation in patients with paroxysmal atrial fibrillation with or without cardiovascular comorbidities. Methods and Results A total of 1633 consecutive patients with paroxysmal atrial fibrillation that were arrhythmia-free for 2 years following the index ablation were classified into: group 1 (without comorbidities); n=692 and group 2 (with comorbidities); n=941. We excluded patients with documented ablation of areas other than pulmonary veins, the left atrial posterior wall, and the superior vena cava at the index procedure. At 10 years after an average of 1.2 procedures, 215 (31%) and 480 (51%) patients had recurrence with median time to recurrence being 7.4 (interquartile interval [IQI] 4.3-8.5) and 5.6 (IQI 3.8-8.3) years in group 1 and 2, respectively. A total of 201 (93.5%) and 456 (95%) patients from group 1 and 2 underwent redo ablation; 147/201 and 414/456 received left atrial appendage and coronary sinus isolation and 54/201 and 42/456 had left atrial lines and flutter ablation. At 2 years after the redo, 134 (91.1%) and 391 (94.4%) patients from group 1 and 2 receiving left atrial appendage/coronary sinus isolation remained arrhythmia-free whereas sinus rhythm was maintained in 4 (7.4%) and 3 (7.1%) patients in respective groups undergoing empirical lines and flutter ablation (P<0.001). Conclusions Very late recurrence of atrial fibrillation after successful isolation of pulmonary veins, regardless of the comorbidity profile, was majorly driven by non-pulmonary vein triggers and ablation of these foci resulted in high success rate. However, presence of comorbidities was associated with significantly earlier recurrence.

Catheter Ablation of Life-Threatening Ventricular Arrhythmias in Athletes.

A recent surveillance analysis indicates that cardiac arrest/death occurs in ≈1:50,000 professional or semi-professional athletes, and the most common cause is attributable to life-threatening ventricular arrhythmias (VAs). It is critically important to diagnose any inherited/acquired cardiac disease, including coronary artery disease, since it frequently represents the arrhythmogenic substrate in a substantial part of the athletes presenting with major VAs. New insights indicate that athletes develop a specific electro-anatomical remodeling, with peculiar anatomic distribution and VAs patterns. However, because of the scarcity of clinical data concerning the natural history of VAs in sports performers, there are no dedicated recommendations for VA ablation. The treatment remains at the mercy of several individual factors, including the type of VA, the athlete's age, and the operator's expertise. With the present review, we aimed to illustrate the prevalence, electrocardiographic (ECG) features, and imaging correlations of the most common VAs in athletes, focusing on etiology, outcomes, and sports eligibility after catheter ablation.

Half-normal saline versus normal saline for irrigation of open-irrigated radiofrequency catheters in atrial fibrillation ablation.

BACKGROUND: The creation of effective and permanent lesions is a crucial factor in determining the success rate of atrial fibrillation (AF) ablation. By increasing the efficacy of radiofrequency (RF) energy-mediated lesion formation, half-normal saline (HNS) as an irrigant for open-irrigated ablation catheters has the potential to reduce procedural times and improve acute and long-term outcomes. METHODS: This is a double-blind randomized clinical trial of 99 patients undergoing first-time RF catheter ablation for AF. Patients enrolled were randomly assigned in a 1:1 fashion to perform ablation using HNS or normal saline (NS) as an irrigant for the ablation catheter. RESULTS: The use of HNS is associated with shorter RF times (26 vs. 33 min; p = .02) with comparable procedure times (104 vs. 104 min). The rate of acute pulmonary vein reconnections (16% vs. 18%) was comparable, with a median of 1 vein reconnection in the HNS arm versus 2 in the NS arm. There was no difference in procedure-related complications, including the incidence of postprocedural hyponatremia when using HNS. Over the 1-year follow-up, there is no significant difference between the HNS and NS with respect to the recurrence of any atrial arrhythmia (off antiarrhythmic drugs [AAD]: 47% vs. 52%; hazard ratio [HR]: 1.17, 95% confidence interval [CI]: 0.66-2.06; off/on AAD: 66% vs. 66%, HR: 1.06, 95% CI: 0.53-2.12), with a potential benefit of using HNS when considering the paroxysmal AF cohort (on/off AAD 73% vs. 62%, HR: 0.72, 95% CI: 0.19-2.70). CONCLUSIONS: In a mixed cohort of patients undergoing first-time AF ablation, irrigation of open-irrigated RF ablation catheters with HNS is associated with shorter RF times, with a comparably low rate of procedure-related complications. In the long term, there is no significant difference with respect to the recurrence of any atrial arrhythmia. Larger studies with a more homogeneous population are necessary to determine whether HNS improves clinical outcomes.

Catheter ablation of ventricular tachycardia in patients with prior cardiac surgery: An analysis from the International VT Ablation Center Collaborative Group.

INTRODUCTION: Patients with prior cardiac surgery may represent a subgroup of patients with ventricular tachycardia (VT) that may be more difficult to control with catheter ablation. METHODS: We evaluated 1901 patients with ischemic and nonischemic cardiomyopathy who underwent VT ablation at 12 centers. Clinical characteristics and VT radiofrequency ablation procedural outcomes were assessed and compared between those with and without prior cardiac surgery. Kaplan-Meier analysis was used to estimate freedom from recurrent VT and survival. RESULTS: There were 578 subjects (30.4%) with prior cardiac surgery identified in the cohort. Those with prior cardiac surgery were older (66.4 ± 11.0 years vs. 60.5 ± 13.9 years, p < .01), with lower left ventricular ejection fraction (30.2 ± 11.5% vs. 34.8 ± 13.6%, p < .01) and more ischemic heart disease (82.5% vs. 39.3%, p < .01) but less likely to undergo epicardial mapping or ablation (9.0% vs. 38.1%, p<.01) compared to those without prior surgery. When epicardial mapping was performed, a significantly greater proportion required surgical intervention for access (19/52 [36.5%] vs. 14/504 [2.8%]; p < .01). Procedural complications, including epicardial access-related complications, were lower (5.7% vs. 7.0%, p < .01) in patients with versus without prior cardiac surgery. VT-free survival (75.1% vs. 74.1%, p = .805) and survival (86.5% vs. 87.9%, p = .397) were not different between those with and without prior heart surgery, regardless of etiology of cardiomyopathy. VT recurrence was associated with increased mortality in patients with and without prior cardiac surgery. CONCLUSION: Despite different clinical characteristics and fewer epicardial procedures, the safety and efficacy of VT ablation in patients with prior cardiac surgery is similar to others in this cohort. The incremental yield of epicardial mapping in predominant ischemic cardiomyopathy population prior heart surgery may be low but appears safe in experienced centers.

High-Dose Dobutamine for Inducibility of Atrial Arrhythmias During Atrial Fibrillation Ablation.

OBJECTIVES: This study sought to compare the effect of high-dose dobutamine (DBT) with that of high-dose isoproterenol (IPN) in eliciting triggers during atrial fibrillation (AF) ablation. BACKGROUND: High-dose IPN is commonly used to elicit triggers during AF ablation. However, it is not available worldwide and, in the United States, its cost per dose has significantly increased. DBT is a similarly nonselective ß-agonist and, as such, is a potential alternative. METHODS: This was a prospective, randomized 2×2 crossover study of patients undergoing AF ablation. Patients were assigned to receive IPN (20 to 30 µg/min for 10 min) followed by DBT (40 to 50 µg/kg/min for 10 min) or vice versa in a 1:1 fashion. The type, number, and location of triggers as well as heart rate, blood pressure, and side effects were noted. RESULTS: Fifty patients were included in the study. Both drugs caused a significant increase in heart rate, with a consistently lower peak for DBT. Blood pressure significantly increased with DBT, while there was a significant reduction with IPN, despite phenylephrine support. Atrial arrhythmias induced during DBT were comparable to that induced during IPN. In patients with IPN-inducible outflow tract premature ventricular contractions, a similar effect was noted with DBT. No major complications occurred during either drug challenge. CONCLUSIONS: High-dose DBT is safe and comparable to high-dose IPN in respect of eliciting AF triggers, with the advantage to maintain systemic pressure without the need of additional vasopressor support. This study supports the use of high-dose DBT in electrophysiology laboratories in which IPN is not readily available and for those patients in whom hypotension is a concern.