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.

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.

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.

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.

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.

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.

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.

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.

Safety and Efficacy of Inpatient Initiation of Dofetilide versus Sotalol for atrial fibrillation

Background

We sought to investigate and compare the safety and efficacy of two commonly used antiarrhythmic drugs, Dofetilide (DF) and Sotalol (SL), during inpatient drug initiation in patients with symptomatic atrial fibrillation (AF).

Methods

We performed a single center retrospective study of consecutive patients, admitted for initiation of either DF or SL, for AF between 2012 and 2015. Rates of successful cardioversion, QT interval prolongation, adverse events and drug discontinuations were calculated and compared. A two-tailed p value less than 0.05 was considered statistically significant.

Results

Of 378 patients, 298 (78.8%) received DF and 80 (21.2%) SL, mean age was 64 ± 11 years, 90% were Caucasians and 66% were males. Among the patients who remained in AF upon admission (DF: 215/298 (72%) vs. SL: 48/80 (60%)), no significant differences were noted in pharmacological cardioversion rates (DF: 125/215(58%) vs. SL: 30/48 (62.5%); p = 0.58). Baseline QTc was similar between the groups, with higher dose dependent QTc prolongation with DF (472.25± 31.3 vs. 458± 27.03; p = 0.008). There were no significant differences in the rates of adverse events such as bradycardia (7.4% vs. 11.3%; p = 0.26), Torsades de pointes (1.3% vs. 1.2%; p = 1.00), and drug discontinuation (9.0% vs. 5.0%; p = 0.47) between the two groups.

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.

Leaks after left atrial appendage ligation with Lariat device: Incidence, pathophysiology, clinical implications and methods of closure- A case based discussion

Catheter based left atrial appendage (LAA) closure techniques are emerging as a promising alternative for stroke prevention in patients who cannot tolerate oral anticoagulation. Lariat procedure involves percutaneous catheter based epicardial ligation of the LAA with a suture via an endo-epicardial hybrid approach. It offers the advantage of not leaving behind a focus for thrombus formation or embolization. Similar to surgical ligation of the left atrial appendage, Lariat ligation is limited by leaks in a small percentage of patients. The incidence of leaks is variable and can be seen in the immediate post procedure period or during follow up. The electrical and mechanical implications of leaks are still under debate. In this review, we discuss the incidence, pathophysiology, clinical implications and methods of closure of leaks after Lariat. In the end, we present a case of a Lariat leak closed with an Amplatzer septal occluder.

Systematic review of non-invasive cardiovascular imaging in the diagnosis of constrictive pericarditis

Background

Diagnosis of constrictive pericarditis (CP) can be challenging. It can be nearly impossible to distinguish CP from other causes of right heart failure. Although various imaging modalities help in the diagnosis, no test is definitive. Several reviews have addressed the role of various imaging techniques in the diagnosis of CP but a systematic review has not yet been published.

Objective

Our intention was to study the ability of various non-invasive imaging modalities to diagnose CP in patients with surgically confirmed disease and to apply our findings to develop a clinically useful diagnostic algorithm.

Methods

A PubMed (NLM) search was performed with MeSH term “constrictive pericarditis”. Original articles that investigated the ability of various cardiovascular imaging modalities to noninvasively diagnose surgically confirmed CP were included in our review. Investigations that included any cases without surgical confirmation were excluded.

Results

The PubMed search yielded 3001 results with MeSH term “constrictive pericarditis” (January 8, 2016). We identified (40) studies on CP that matched our inclusion criteria. We summarized our results sorted by individual non-invasive CV imaging modalities – echocardiography, cardiac computed tomography (CT), and magnetic resonance imaging (MRI). Under each imaging modality, we grouped our discussion based on different parameters useful in CP diagnosis.

Conclusions

In conclusion, contemporary diagnosis of CP is based on clinical features and echocardiography. Cardiac MRI is recommended in patients where echocardiography is not diagnostic. Both cardiac MRI and CT can guide surgical planning but we prefer MRI as it provides both structural and functional information.