Left Atrial Appendage Occlusion Device Embolization (The LAAODE Study): Understanding the Timing and Clinical Consequences from a Worldwide Experience.

BACKGROUND: Left atrial appendage occlusion device embolization (LAAODE) is rare but can have substantial implications on patient morbidity and mortality. Hence, we sought to perform an analysis to understand the timing and clinical consequences of LAAODE. METHODS: A comprehensive search of PubMed and Web of Science databases for LAAODE cases was performed from October 2nd, 2014 to November 1st, 2017. Prior to that, we included published LAAODE cases until October 1st, 2014 reported in the systematic review by Aminian et al. RESULTS: 103 LAAODE cases including Amplatzer cardiac plug (N=59), Watchman (N=31), Amulet (N=11), LAmbre (N=1) and Watchman FLX (N=1) were included. The estimated incidence of device embolization was 2% (103/5,000). LAAODE occurred more commonly in the postoperative period compared with intraoperative (61% vs. 39%). The most common location for embolization was the descending aorta 30% (31/103) and left atrium 24% (25/103) followed by left ventricle 20% (21/103). Majority of cases 75% (77/103) were retrieved percutaneously. Surgical retrieval occurred most commonly for devices embolized to the left ventricle, mitral apparatus and descending aorta. Major complications were significantly higher with postoperative LAAODE compared with intraoperative (44.4% vs. 22.5%, p=0.03). CONCLUSIONS: LAAODE is common with a reported incidence of 2% in our study. Post-operative device embolization occurred more frequently and was associated with a higher rate of complications than intraoperative device embolizations. Understanding the timings and clinical sequelae of DE can aid physicians with post procedural follow-up and also in the selection of patients for these procedures.

Outcomes of junctional ectopic tachycardia ablation in adult population-a multicenter experience.

PURPOSE: Idiopathic junctional ectopic tachycardia (JET) is typically refractory to antiarrhythmic agents. Catheter ablation for JET is feasible but is associated with high risk of unintended atrioventricular (AV) block. There is limited data on the appropriate procedural technique and clinical outcomes with catheter ablation for idiopathic JET in adults. METHODS: This is a multicenter, retrospective study of all adult patients (age ≥ 18 years) who underwent catheter ablation for idiopathic JET. Patient, procedural characteristics, and long-term outcomes were evaluated. RESULTS: Fifteen patients [radiofrequency ablation (RF) = 14 and cryoablation = 1) were treated with catheter ablation. The median age was 58 years with 67% males. All patients underwent mapping of the right atrium and the aortic cusps prior to energy delivery. The location of earliest activation in relation to the atrioventricular (AV) node was postero-superior in 73% (11/15), posterior in 13% (2/15), and superior in 13% (2/15) respectively. Acute success was 100%. Arrhythmia recurrence occurred in 53% (8/15) all of whom underwent a repeat ablation. High-grade AV block requiring permanent pacemaker occurred in 20% (3/15). At 12-month follow-up in the redo-ablation group, 37.5% (3/8) had recurrence of the arrhythmia two of which underwent a third ablation procedure. CONCLUSION: Catheter ablation of idiopathic JET in adults is associated with a high rate of recurrence requiring multiple procedures and high risk of AV block requiring a permanent pacemaker. Mapping and ablation of the non-coronary cusp can be considered as the arrhythmia was controlled in 3 patients with no inadvertent AV block.

Role of the Left Atrial Appendage in Systemic Homeostasis, Arrhythmogenesis, and Beyond.

The left atrial appendage (LAA) affects body homeostasis via atrial natriuretic peptide and the renin-angiotensin-aldosterone system and plays an important role in atrial compliance. Approximately 90% of clots in nonvalvular atrial fibrillation (AF) are formed in the LAA. AF is the most common sustained cardiac arrhythmia and is frequently associated with stroke. Because anticoagulation for stroke prophylaxis carries a higher bleeding risk, LAA closure via epicardial and endocardial approaches has gained popularity and is being increasingly pursued for arrhythmogenic, homeostatic, and stroke-reduction benefits. This review discusses the homeostatic role of the LAA and its involvement in arrhythmogenesis and thrombus formation.

Epicardial versus Endocardial Closure: Is One Better than the Other?

Left atrial appendage occlusion is an evolving technology with demonstrable benefits of stroke prophylaxis in patients with atrial fibrillation unsuitable for anticoagulation. This has resulted in the development of a plethora of transcatheter devices to achieve epicardial exclusion and endocardial occlusion. In this review, the authors summarize the differences in technique, target patient population, outcomes, and complication profiles of endocardial and epicardial techniques.

Exclusion of electrical and mechanical function of the left atrial appendage in patients with persistent atrial fibrillation: differences in efficacy and safety between endocardial ablation vs epicardial LARIAT ligation (the EXCLUDE LAA study).

BACKGROUND: Electrical isolation of the left atrial appendage (LAA) may provide incremental benefits for arrhythmia management in patients undergoing radiofrequency ablation (RFA) for persistent atrial fibrillation (AF). OBJECTIVE: The aim of this study was to compare efficacy and safety of endocardial ablation and LAA exclusion with LARIAT device for electrical and mechanical exclusion of LAA. METHODS: We compared patients who underwent endocardial LAA isolation during index RFA for persistent AF and underwent a repeat RFA to patients who underwent LAA exclusion with LARIAT device followed by RFA for AF in this multicenter registry. Efficacy of electrical and mechanical isolation of LAA was assessed. RESULTS: We included 182 patients of which 91 patients underwent endocardial LAA isolation during RFA for AF, and 91 patients underwent LAA exclusion with LARIAT device followed by RFA for AF. Baseline characteristics were similar except for higher CHA2DS2-VASc score, coronary artery disease, and prior stroke rate in LARIAT arm. Persistence of electrical isolation (measured at beginning of second procedure) after LARIAT procedure was higher than one-time AF-RFA (96.7% vs 52.8%, p < 0.01). Acute pulmonary vein isolation rates were similar in both arms. AF recurrence rate after second isolation attempts at 1 year was similar in both arms. No difference in major complications was noted between both arms. CONCLUSIONS: LAA exclusion with LARIAT device appears to be more efficacious as compared to one-time endocardial ablation, but not compared to repeat isolation, in achieving complete electrical isolation of LAA for persistent AF.

Myocarditis Causing Premature Ventricular Contractions: Insights From the MAVERIC Registry.

BACKGROUND: Premature ventricular contractions are a common clinical presentation that drives further diagnostic workup. We hypothesize the presence of underlying inflammation is often unrecognized in these patients with a potential for continued disease progression if not diagnosed and treated early in the disease course. METHODS: This is a single-center, prospective study including 107 patients with frequent symptomatic premature ventricular contractions (>5000/24 h) and no known ischemic heart disease. Patients underwent a combination of laboratory testing, 18F-fluorodeoxyglucose positron emission tomography scan, cardiac magnetic resonance imaging, and biopsy. Patients were diagnosed with myocarditis based on a multidisciplinary approach and treated with immunosuppressive therapy. RESULTS: The mean age of the cohort was 57±15 years, 41% were males, and left ventricular ejection fraction was 47±11.8%. Positive positron emission tomography scan was seen in 51% (55/107), of which 51% (28/55) had preserved left ventricle function. Based on clinical profile, 18F-fluorodeoxyglucose-positron emission tomography imaging, cardiac magnetic resonance, and histological data 58% patients (32/55) received immunosuppressive therapy alone and 25.4% (14/55) received immunosuppressive therapy and catheter ablation. Optimal response was seen in 67% (31/46) over a mean follow-up of 6±3 months. In patients with left ventricle systolic dysfunction, 37% (10/27) showed an improvement in mean left ventricular ejection fraction of 13±6%. CONCLUSIONS: Approximately 51% of patients presenting with frequent premature ventricular contractions have underlying myocardial inflammation in this cohort. 18F-fluorodeoxyglucose-positron emission tomography scan can be a useful modality for early diagnosis and treatment with immunosuppressive therapy in selected patients can improve clinical outcomes.

Simplified Rapid Protocol for Assessing the Thoracic Aortic Dimensions and Pathology with Noncontrast MR Angiography.

Contrast enhanced magnetic resonance angiography (CE-MRA) is limited by long acquisition time and contrast exposure in aortic emergencies. To compare the effcacy of dark blood (DB) and bright blood (BB) noncontrast sequences with the gold standard CE-MRA using a novel protocol for performing consistent thoracic aortic measurements and thoracic aortic pathologies identifications. A total of 66 patients with suspected or known thoracic aortic pathology who underwent CE-MRA underwent DB and BB imaging prior to CE-MRA for planning purposes. Aortic dimension was measured at 10 standard reference points in the ascending, arch, and descending aorta. Detection of aortic pathologies was recorded individually for each noncontrast sequence. When comparing the CE-MRA to the DB images and CE-MRA to the BB images, a majority of the measurement differences were less than or equal to 2 mm or resulted in no change of diagnostic class (95% for CE-MRA vs. DB and 96% for CE-MRA vs. BB). Of the patients who had major changes in diagnostic class (e.g., changes in two or three classes), the absolute measurements were not clinically significant in any given patient to warrant a change in management. Individually, the DB and BB sequences allowed for accurate recognition of all 47 aortic pathologies. DB and BB sequences produced comparable and consistent measurements of the thoracic aorta when compared with CE-MRA. In a situation where CE-MRA is not readily available or contraindicated, noncontrast MRA using our protocol is a reliable alternative to CE-MRA for assessment of aortic pathologies.

Percutaneous ventricular assist device in ventricular tachycardia ablation: a systematic review and meta-analysis.

BACKGROUND: There is a lack of compelling data regarding the benefit of percutaneous ventricular assist devices (PVAD) in patients undergoing ventricular tachycardia (VT) ablation. The study aims to conduct a meta-analysis comparing the safety and efficacy of PVAD versus no-PVAD (N-PVAD) during VT ablation. METHODS: Studies meeting criteria were systematically reviewed. Baseline characteristics and clinical outcomes were extracted and analyzed. A meta-analysis was performed using random-effects model to calculate risk ratio (RR) and mean difference (MD) with 95% confidence interval (CI). RESULTS: The meta-analysis included five retrospective, observational studies consisting of 2026 patients (PVAD group-284 patients versus N-PVAD group-1742 patients). The PVAD group was sicker with significantly higher VT storm, lower LVEF and greater proportion of NYHA class ≥ III than N-PVAD (p < 0.050). The acute procedural success [RR 0.95, 95% CI, (0.89-1.00), p = 0.070], VT recurrence [RR 0.94, 95% CI, (0.66-1.34), p = 0.740] and mortality [RR 1.28, 95% CI, (0.43-3.83), p = 0.660] were similar on follow-up between PVAD versus N-PVAD. PVAD group also had significantly higher complications [RR 1.83, 95% CI (1.21-2.76), p = 0.004] and longer fluoroscopy [MD + 7.31 min, 95% CI (0.91-13.71), p = 0.030] and procedure time [MD + 71.41 min, 95% CI (31.67-111.14), p < 0.001] than N-PVAD. CONCLUSION: Patients receiving PVAD support during VT ablation were sicker with no significant difference in acute procedural success, VT recurrence, and mortality compared with N-PVAD. PVAD support was also associated with higher complications and longer fluoroscopy and procedure time. A prospective randomized controlled trial will identify if using PVAD support in unstable patients undergoing VT ablation will impact clinical outcomes.

Dofetilide Initiation and Implications of Deviation From the Standard Protocol - A Real World Experience.

BACKGROUND: Manufacturer/federal drug administration (FDA) recommends inpatient initiation of dofetilide with the manufacturer providing an initiation algorithm. The outcomes of algorithm deviation have not been reported outside of clinical trials. OBJECTIVE: We sought to perform a chart review of all the patients admitted for inpatient initiation of dofetilide to report on the incidence of protocol deviations and their implications. METHODS: We performed a retrospective review of all patients over a 15-month periodwho were initiated on dofetilide for the very first time or reinitiated on dofetilide after a break of three months or more at our institution. We assessed data about patients who were given dofetilide without adherence to the protocol (i.e. protocol deviation). RESULTS: A total of 189 patients were included in the study with a median age of 66 ± 9 years. Mean baseline QTc interval was 436 ± 32 msec, and 61% (116/189) were in atrial fibrillation (AF) at the time of dofetilide initiation. In 9% (17/189) of patients, the drug was discontinued due to intolerance or inefficacy. Therapy in 49% (93/189) of patients was noted to deviate from manufacturer recommended protocol with deviations more than once in some patients during the same hospitalization. Baseline QTc exceeding 440 msec(>500msec in conduction abnormalities) was the most frequent deviation (25%; 47/189).Ventricular tachyarrhythmia occurred in 4% (7/189) of patients, did not differ between patients, and occurred with and without protocol deviations (5% vs 2%; p = 0.27). CONCLUSIONS: In our retrospective study, there were frequent deviations from the manufacturer-recommended algorithm guidelines for dofetilideinitation, primarily due to prolonged baseline QTc interval. The impact of these protocol deviations on drug discontinuation was uncertain; however, significant adverse events were higher in the deviation group compared to the group that fully adhered to the protocol. Further multicenter studies are warranted to clarify our findings.

Temporal relationships between esophageal injury type and progression in patients undergoing atrial fibrillation catheter ablation.

BACKGROUND: Currently, little is known about the onset, natural progression, and management of esophageal injuries after atrial fibrillation (AF) ablation. OBJECTIVES: We sought to provide a systematic review on esophageal injury after AF ablation and identify temporal relationships between various types of esophageal lesions, their progression, and clinical outcomes. METHODS: A comprehensive search of PubMed and Web of Science was conducted until September 21, 2017. All AF ablation patients who underwent upper gastrointestinal endoscopy within 1 week of the procedure were included. Patients with esophageal lesions were classified into 3 types by using our novel Kansas City classification: type 1: erythema; type 2a: superficial ulcers; type 2b: deep ulcers; type 3a: perforation without communication with the atria; and type 3b: perforation with atrioesophageal fistula. RESULTS: Thirty studies met our inclusion criteria. Of the 4473 patients, 3921 underwent upper gastrointestinal evaluation. The overall incidence of esophageal injuries was 15% (570). There were 206 type 1 lesions (36%), 222 type 2a lesions (39%), and 142 type 2b lesions (25%). Six of 142 type 2b lesions (4.2%) progressed further to type 3, of which, 5 were type 3a and 1 was type 3b. All type 1 and type 2a and most type 2b lesions resolved with conservative management. One type 3a and 1 type 3b lesions were fatal. CONCLUSION: Based on our classification, all type 1 and most type 2 lesions resolved with conservative management. A small percentage (4.2% [6 of 142]) of type 2b lesions progressed to perforation and/or fistula formation, and these patients need to be followed closely.

Successful Percutaneous Closure of Traumatic Right Ventricular Free Wall Rupture Using Amplatzer Vascular Plug Devices.

Ventricular free wall rupture (VFWR) is a rare entity and is mostly related to post myocardial infarction (MI) complications usually involving left ventricle. In traumatic chest injuries, the right ventricle (RV) is more commonly involved due to its anatomic and structural vulnerability, as in our case. Survival, although rare, has almost always been secondary to urgent surgical repair, which is the current standard of care for such cases. However, extremely tenuous hemodynamic parameters preclude urgent surgical interventions in most of these cases. Surgical repair was considered to have prohibitive risk in our case also due to multiple comorbidities. Our case offers a unique perspective into the feasibility and safety of percutaneous closure of VFWR with devices such as Amplatzer Vascular Plug (AVP) II under transesophageal echocardiography (TEE) and angiographic guidance in patients who survive VFWR. The lack of randomized evidence to standardize the duration and regimen of antiplatelet therapy following placement of these devices is to be noted.

Esophageal laceration related to mechanical trauma from a General Purpose (esophageal/rectal) temperature probe introducer sheath during atrial fibrillation ablation.

Catheter Radiofrequency ablation (RFA) for the management of atrial fibrillation (AF) can be associated with serious thermal injuries of the esophagus due to the close proximity of later. Use of Esophageal/Rectal temperature monitoring probes have become a standard practice now during these procedures in order to prevent such complications. However these probes need small introducer sheaths in order to guide them into the esophagus without coiling. Due to the small size of these sheaths, they can easily get dislodged into the trachea or esophagus and cause serious complications including mucosal lacerations.

Feasibility, safety, and efficacy of a novel preshaped nitinol esophageal deviator to successfully deflect the esophagus and ablate left atrium without esophageal temperature rise during atrial fibrillation ablation: The DEFLECT GUT study.

BACKGROUND: Esophageal thermal injury is a feared complication of radiofrequency ablation for atrial fibrillation (AF). Rise in luminal esophageal temperature (LET) limits the ability to deliver radiofrequency energy on the posterior wall of the left atrium. OBJECTIVE: The purpose of this study was to evaluate the feasibility, safety, and efficacy of a mechanical esophageal deviation (ED) tool during AF ablation. METHODS: We evaluated 687 patients who underwent radiofrequency ablation for AF. In 209 patients, the EsoSure (Northeast Scientific) was used to deflect the esophagus away from the ablation site. Propensity score matching was performed to obtain 180 patients each in the ED and non-ED arms. ED was used for LET rise seen in 61.7% of patients (111/180) and was used if the esophagus was in the line of ablation on fluoroscopy in 38.3% of patients (69/180). RESULTS: Mean deviation of trailing edge of esophagus with EsoSure was 2.45 ± 0.9 cm (range 1-4.5). LET rise >1°C was significantly lower in the ED than non-ED group (3% vs 79.4%; P <.001). Mean LET rise was also lower in the ED arm (ED 0.34 ± 0.59 vs non-ED 1.66 ± 0.54; P <.001). Intraprocedural success of pulmonary vein antral isolation, was slightly improved in the ED arm than in the non-ED arm without statistical significance. AF recurrence was lower in the ED arm at 3-month, 6-month, and 1-year follow-up than in the non-ED arm. No ED-related complications were noted. CONCLUSION: Mechanical displacement of the esophagus with EsoSure seems to be feasible, safe, and efficacious in enabling adequate radiofrequency energy delivery to the posterior wall of the left atrium without significant LET rise and obvious clinical signs of esophageal injury.

Safety and feasibility of leadless pacemaker in patients undergoing atrioventricular node ablation for atrial fibrillation.

BACKGROUND: Atrioventricular node (AVN) ablation and permanent pacing is an established strategy for rate control in the management of symptomatic atrial fibrillation (AF). Leadless pacemakers (LPs) can overcome some of the short-term and long-term limitations of conventional transvenous pacemakers (CTPs). OBJECTIVES: The purpose of this study was to compare the feasibility and safety of LP with those of single-chamber CTP in patients with AF undergoing AVN ablation. METHODS: We conducted a multicenter observational study of patients undergoing AVN ablation and pacemaker implantation (LP vs single-chamber CTP) between February 1, 2014 and November 15, 2016. The primary efficacy end points were acceptable sensing (R wave amplitude ≥5.0 mV) and pacing thresholds (≤2.0 V at 0.4 ms) at follow-up. Safety end points included device-related major and minor (early <1 month, late >1 month) adverse events. RESULTS: A total of 127 patients with LP (n = 60) and CTP (n = 67) were studied. The median follow-up was 12 months (interquartile range 12-18 months). Ninety-five percent of the LP group and 97% of the CTP group met the primary efficacy end point at follow-up (57 of 60 vs 65 of 67; P = .66). There was 1 major adverse event (loss of pacing and sensing) in the LP group and 2 (lead dislodgement) in the CTP group (1 of 60 vs 2 of 67; P = 1.00). There were 6 minor adverse events (5 early and 1 late) in the LP group and 3 (early) in the CTP group (6 of 60 vs 3 of 67; P = .30). CONCLUSION: Our results demonstrate the feasibility and safety of LP compared with CTP in patients undergoing AVN ablation for AF.

Indication, Patient Selection, and Referral Pathways for Left Atrial Appendage Closure.

Left atrial appendage closure (LAAC) has emerged as a viable option for stroke prevention, especially in those intolerant of or not suitable for long-term oral anticoagulation therapy. This article describes the clinical characteristics, indications, and a proposed referral system for potential LAAC patients. Patient selection remains a challenge because of the paradox between the available randomized data on this intervention and the actual patient population who may gain maximum benefit. Further investigations comparing different LAAC devices with each other and with novel oral anticoagulants are needed. Also, the optimal antithrombotic regimen post-procedure has yet to be determined.

Mechanical function of the left atrium is improved with epicardial ligation of the left atrial appendage: Insights from the LAFIT-LARIAT Registry.

BACKGROUND: Left atrial (LA) strain (ε) and ε rate (SR) analysis by 2-dimensional speckle tracking echocardiography is a novel method for functional assessment of the LA. OBJECTIVE: The purpose of this study was to determine the impact of left atrial appendage (LAA) exclusion by Lariat epicardial ligation on mechanical function of the LA by performing ε and SR analysis before and after the procedure. METHODS: A total of 66 patients who underwent successful LAA exclusion were included in the study. Of these 66 patients, 32 had adequate paired data for ε and SR analysis. SR during ventricular systole (LA-SRs) represents LA reservoir function, and SR during early ventricular diastole (LA-SRe) represents LA conduit function. ε and SR were determined from apical 4- and 2-chamber views using the electrocardiographic QRS as a reference point. LA volume index as surrogate for LA remodeling was measured from apical views. RESULTS: Mean patient age was 70 ± 9.2 years. LAA ligation resulted in improved reservoir function (LA-SRs: pre 0.72, confidence interval [CI] 0.63-0.83 vs post 0.81, CI 0.73-0.98; P = .043) and conduit function (LA-SRe: pre 0.74, CI 0.67-0.99 vs post 0.89, CI 0.82-1.07; P = .025). LA volume index improved significantly with the Lariat (pre 35.4, CI 29.4-37.2 vs post 29.2, CI 28.2-35.9; P <.023). CONCLUSION: LAA exclusion seems to improve mechanical function of the LA and results in reverse LA remodeling.

Congenital Absence of Left Atrial Appendage.

Isolated absence of left atrial appendage is a very rare entity and is usually encountered as an incidental finding during routine imaging for other purposes. Lately, with increasing fund of knowledge about its potential role in cardio embolic phenomena, we have seen an increased trend in the use different techniques to exclude left atrial appendage from main left atrial chamber, in an effort to alleviate the stroke risk and therefore the need for long term anticoagulation. Clinical implications of absent left atrial appendage in such patients remains a mystery.