Safety of percutaneous left atrial appendage closure: results from the Watchman Left Atrial Appendage System for Embolic Protection in Patients with AF (PROTECT AF) clinical trial and the Continued Access Registry

[Implantation of Watchman™ occluder of the left atrial appendage. Tips and tricks]

The implantation of an occluder system for the left atrial appendage (LAA) represents an interesting alternative for patients with atrial fibrillation and a CHA2DS2-VASc-Score ≥ 2 who cannot take permanent anticoagulation for various reasons. As in other left cardiac interventions, there are potentially dangerous possibilities for complications that can limit the advantages of this therapy. This overview summarizes practical tips and tricks at the implantation of a Watchman™ occluder which may help to minimize the complication rate. These hints refer to peri-interventional anticoagulation as well as transseptal puncture (technique, imaging), exchange of catheters, left atrial pressure, intubation and fluoroscopy of the LAA, preparation of the device and sheath, delivery of the Watchman™ device, confirmation of optimal position, and partial or complete recapture. If these precautions are considered, the complication rate at implantation of a Watchman™ occluder should be < 5 %, the rate of complications with long-term consequences < 1 %, and the implant success should lie > 95 %.

[Interventional left atrial appendage occlusion : alternative to oral anticoagulation for stroke prevention in atrial fibrillation]

Stroke prevention in patients with atrial fibrillation is one of the greatest challenges in modern cardiology. Interventional left atrial appendage occlusion is an alternative to oral anticoagulation in patients with non-valvular atrial fibrillation. This procedure is currently used mainly for patients with elevated risk for bleeding complications (HAS-BLED score ≥3) or other contraindications for oral anticoagulation. The novel anticoagulants dabigatran, rivaroxaban and apixaban carry a risk for major bleeding for 2-3% of patients per year. The indications for an interventional left atrial appendage closure are therefore not affected by these substances. Several devices have been developed for this purpose; however, currently only the WATCHMAN® and AMPLATZER® cardiac plug are used in the clinical routine in Germany. The WATCHMAN® device proved to be non-inferior to oral anticoagulation with warfarin in the PROTECT-AF trial in terms of safety and efficacy. These findings are supported by data from registries with up to 5 years follow-up. For the second device currently used in clinical practice, the AMPLATZER® cardiac plug, there is increasing data from registries suggesting comparable safety and efficacy. Both devices necessitate anticoagulation during the first 3-6 months after implantation until endothelialization is completed. Due to the anatomical complexity the implantation should be performed in experienced centers with reduction of the periprocedural risk to <1%. Thus, interventional left atrial appendage occlusion is a valid option to prevent stroke or other thromboembolic events in non-valvular atrial fibrillation especially for elderly patients or those with a history of bleeding complications.

Left atrial appendage closure with the Watchman device in patients with a contraindication for oral anticoagulation: the ASAP study (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology)

OBJECTIVES

The purpose of this study was to assess the safety and efficacy of left atrial appendage (LAA) closure in nonvalvular atrial fibrillation (AF) patients ineligible for warfarin therapy.

BACKGROUND

The PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that LAA closure with the Watchman device (Boston Scientific, Natick, Massachusetts) was noninferior to warfarin therapy. However, the PROTECT AF trial only included patients who were candidates for warfarin, and even patients randomly assigned to the LAA closure arm received concomitant warfarin for 6 weeks after Watchman implantation.

METHODS

A multicenter, prospective, nonrandomized study was conducted of LAA closure with the Watchman device in 150 patients with nonvalvular AF and CHADS₂ (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score ≥1, who were considered ineligible for warfarin. The primary efficacy endpoint was the combined events of ischemic stroke, hemorrhagic stroke, systemic embolism, and cardiovascular/unexplained death.

RESULTS

The mean CHADS₂ score and CHA₂DS₂-VASc (CHADS₂ score plus 2 points for age ≥75 years and 1 point for vascular disease, age 65 to 74 years, or female sex) score were 2.8 ± 1.2 and 4.4 ± 1.7, respectively. History of hemorrhagic/bleeding tendencies (93%) was the most common reason for warfarin ineligibility. Mean duration of follow-up was 14.4 ± 8.6 months. Serious procedure- or device-related safety events occurred in 8.7% of patients (13 of 150 patients). All-cause stroke or systemic embolism occurred in 4 patients (2.3% per year): ischemic stroke in 3 patients (1.7% per year) and hemorrhagic stroke in 1 patient (0.6% per year). This ischemic stroke rate was less than that expected (7.3% per year) based on the CHADS₂ scores of the patient cohort.

CONCLUSIONS

LAA closure with the Watchman device can be safely performed without a warfarin transition, and is a reasonable alternative to consider for patients at high risk for stroke but with contraindications to systemic oral anticoagulation. (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology [ASAP]; NCT00851578).

Recommendations for thromboprophylaxis in the 2012 focused update of the ESC guidelines on atrial fibrillation: a commentary

The objective of this article is to provide a commentary on the recommendations for stroke prevention from the 2012 focused update of the European Society of Cardiology guidelines on the management of atrial fibrillation and the evidence (or lack of it) supporting these recommendations. These guidelines strongly advocate a major clinical practice shift towards initially focusing on the identification of 'truly low risk' patients who do not need any antithrombotic therapy. After this initial decision-making step, effective stroke prevention - that is, oral anticoagulation therapy (whether as well-controlled adjusted dose warfarin or with one of the novel oral anticoagulants) - could be offered to patients with atrial fibrillation with ≥ 1 stroke risk factors. The 2012 focused update guideline also provides additional guidance on advances in stroke and bleeding risk assessment that are evident since publication of the 2010 guideline, as well as recommendations on the use of the novel oral anticoagulants and the left atrial appendage occlusion devices that have been increasingly used in European clinical practice over the last 2 years.

Percutaneous closure of the left atrial appendage for thromboembolic prevention in atrial fibrillation

Atrial fibrillation is a common arrhythmia in clinical practice. It is associated with high morbidity and mortality due to its thromboembolic potential, which makes thromboembolic prevention particularly important. Warfarin has been the first-line therapy for this purpose, but it has various limitations and is often contraindicated or underutilized. The fact that thrombi are frequently located in the left atrial appendage in atrial fibrillation led to the development of percutaneous closure for thromboembolic prevention. This article examines the current evidence on percutaneous closure of the left atrial appendage by reviewing the results of the numerous clinical trials on the technique.

Amplatzer left atrial appendage occlusion: single center 10-year experience

OBJECTIVES

To report a 10-year single center experience with Amplatzer devices for left atrial appendage (LAA) occlusion.

BACKGROUND

Intermediate-term outcome data following LAA occlusion are scarce.

METHODS

Short- and intermediate-term outcomes of patients who underwent LAA occlusion were assessed. All procedures were performed under local aesthesia without transesophageal echocardiography. Patients were discharged on acetylsalicylic acid and clopidogrel for 1-6 months.

RESULTS

LAA occlusion was attempted in 152 patients (105 males, age 72 ± 10 years, CHA2 DS2 -Vasc-score 3.4 ± 1.7, HAS-BLED-score 2.4 ± 1.2). Nondedicated devices were used in 32 patients (21%, ND group) and dedicated Amplatzer Cardiac Plugs were used in 120 patients (79%, ACP group). A patent foramen ovale or atrial septal defect was used for left atrial access and closed at the end of LAA occlusion in 40 patients. The short-term safety endpoints (procedural complications, bleeds) occurred in 15 (9.8%) and the efficacy endpoints (death, stroke, systemic embolization) in 0 patients. Device embolization occurred more frequently in the ND as compared to the ACP group (5 patients or 12% vs. 2 patients or 2%). Mean intermediate-term follow up of the study population was 32 months (range 1-120). Late deaths occurred in 15 patients (5 cardiovascular, 7 noncardiac, 3 unexplained). Neurologic events occurred in 2, peripheral embolism in 1, and major bleeding in 4 patients. The composite efficacy and safety endpoint occurred in 7% and 12% of patients.

CONCLUSION

LAA closure may be a good alternative to oral anticoagulation. This hypothesis needs to be tested in a randomized clinical trial to ensure that all potential biases of this observational study are accounted for.

Does left atrial appendage closure with a cardiac plug system reduce the stroke risk in nonvalvular atrial fibrillation patients? A single-center case series

BACKGROUND

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and it is associated with an increased stroke risk, due mainly to cardiac embolism from the left atrial appendage (LAA). Percutaneous LAA closure is a method to reduce stroke risk in AF without using anticoagulant agents. In this study we report data from an Italian experience with the LAA occluder Amplatzer Cardiac Plug (ACP) device (Aga Medical Corporation, Plymouth, MN, USA).

METHODS

The study was designed to evaluate the safety of LAA closure using ACP and the efficacy of the procedure in preventing strokes during a 1-year follow-up. Patients with permanent or paroxysmal AF, high stroke risk, and contraindication to warfarin therapy were selected for the procedure.

RESULTS

The LAA closure was attempted in 37 patients and succeeded in 34 cases (91.9%). Four patients experienced serious complications (one cardiac tamponade requiring pericardiocentesis, two device embolizations, one low-rate response AF requiring artificial pacing). During a 1-year follow-up, ischemic stroke occurred in one of 34 patients, resulting in a stroke rate of 2.94%; thus there was a stroke rate reduction of 50.2% and 26.5% compared to the expected stroke rate, according to CHADS2 and CHA2 DS2 VASc score. None of the patients who received ACP experienced major bleeding during the follow-up.

CONCLUSION

LAA closure using ACP is a relatively feasible procedure which can be performed by highly experienced operators to reduce stroke rate in patients with AF, high stroke risk, and contraindication to oral anticoagulants.

Catheter ablation in combination with left atrial appendage closure for atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide. The rapid, irregular, and disordered electrical activity in the atria gives rise to palpitations, fatigue, dyspnea, chest pain and dizziness with or without syncope. Patients with AF have a five-fold higher risk of stroke. Oral anticoagulation (OAC) with warfarin is commonly used for stroke prevention in patients with AF and has been shown to reduce the risk of stroke by 64%. Warfarin therapy has several major disadvantages, however, including bleeding, non-tolerance, interactions with other medications and foods, non-compliance and a narrow therapeutic range. These issues, together with poor appreciation of the risk-benefit ratio, unawareness of guidelines, or absence of an OAC monitoring outpatient clinic may explain why only 30-60% of patients with AF are prescribed this drug. The problems associated with warfarin, combined with the limited efficacy and/or serious side effects associated with other medications used for AF, highlight the need for effective non-pharmacological approaches to treatment. One such approach is catheter ablation (CA), a procedure in which a radiofrequency electrical current is applied to regions of the heart to create small ablation lesions that electrically isolate potential AF triggers. CA is a well-established treatment for AF symptoms, that may also decrease the risk of stroke. Recent data showed a significant decrease in the relative risk of stroke and transient ischemic attack events among patients who underwent ablation compared with those undergoing antiarrhythmic drug therapy. Since the left atrial appendage (LAA) is the source of thrombi in more than 90% of patients with non-valvular atrial fibrillation, another approach to stroke prevention is to physically block clots from exiting the LAA. One method for occluding the LAA is via percutaneous placement of the WATCHMAN LAA closure device. The WATCHMAN device resembles a small parachute. It consists of a nitinol frame covered by fabric polyethyl terephthalate that prevents emboli, but not blood, from exiting during the healing process. Fixation anchors around the perimeter secure the device in the LAA (Figure 1). To date, the WATCHMAN is the only implanted percutaneous device for which a randomized clinical trial has been reported. In this study, implantation of the WATCHMAN was found to be at least as effective as warfarin in preventing stroke (all-causes) and death (all-causes). This device received the Conformité Européenne (CE) mark for use in the European Union for warfarin eligible patients and in those who have a contraindication to anticoagulation therapy. Given the proven effectiveness of CA to alleviate AF symptoms and the promising data with regard to reduction of thromboembolic events with both CA and WATCHMAN implantation, combining the two procedures is hoped to further reduce the incidence of stroke in high-risk patients while simultaneously relieving symptoms. The combined procedure may eventually enable patients to undergo implantation of the WATCHMAN device without subsequent warfarin treatment, since the CA procedure itself reduces thromboembolic events. This would present an avenue of treatment previously unavailable to patients ineligible for warfarin treatment because of recurrent bleeding or other warfarin-associated problems. The combined procedure is performed under general anesthesia with biplane fluoroscopy and TEE guidance. Catheter ablation is followed by implantation of the WATCHMAN LAA closure device. Data from a non-randomized trial with 10 patients demonstrates that this procedure can be safely performed in patients with a CHADS2 score of greater than 1. Further studies to examine the effectiveness of the combined procedure in reducing symptoms from AF and associated stroke are therefore warranted.

[Update on interventional cardiology]

This article contains a review of the most important studies on interventional cardiology reported in either publications or presentations. In the area of coronary interventions, ST-elevation myocardial infarction continues to take center place: recent studies have confirmed the importance of timely intervention and the safety of drug-eluting stents. The numerous studies that have compared different generations of drug-eluting stents indicate that there has been a steady improvement in safety and efficacy. In addition, the use of stents in the left main coronary artery and in multivessel disease have also been investigated in major studies. Of the different intracoronary diagnostic techniques, optical coherence tomography is highlighted by this review, particularly for its use in the study of drug-eluting stents. There is increasing interest in the percutaneous treatment of structural heart disease, specifically percutaneous aortic valve implantation, especially following the publication of the first randomized trial, which produced encouraging results.

Percutaneous left atrial appendage closure for stroke prophylaxis in patients with atrial fibrillation: 2.3-Year Follow-up of the PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients with Atrial Fibrillation) Trial

BACKGROUND

The multicenter PROTECT AF study (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) was conducted to determine whether percutaneous left atrial appendage closure with a filter device (Watchman) was noninferior to warfarin for stroke prevention in atrial fibrillation.

METHODS AND RESULTS

Patients (n=707) with nonvalvular atrial fibrillation and at least 1 risk factor (age >75 years, hypertension, heart failure, diabetes, or prior stroke/transient ischemic attack) were randomized to either the Watchman device (n=463) or continued warfarin (n=244) in a 2:1 ratio. After device implantation, warfarin was continued for ≈45 days, followed by clopidogrel for 4.5 months and lifelong aspirin. Study discontinuation rates were 15.3% (71/463) and 22.5% (55/244) for the Watchman and warfarin groups, respectively. The time in therapeutic range for the warfarin group was 66%. The composite primary efficacy end point included stroke, systemic embolism, and cardiovascular death, and the primary analysis was by intention to treat. After 1588 patient-years of follow-up (mean 2.3±1.1 years), the primary efficacy event rates were 3.0% and 4.3% (percent per 100 patient-years) in the Watchman and warfarin groups, respectively (relative risk, 0.71; 95% confidence interval, 0.44%-1.30% per year), which met the criteria for noninferiority (probability of noninferiority >0.999). There were more primary safety events in the Watchman group (5.5% per year; 95% confidence interval, 4.2%-7.1% per year) than in the control group (3.6% per year; 95% confidence interval, 2.2%-5.3% per year; relative risk, 1.53; 95% confidence interval, 0.95-2.70).

CONCLUSIONS

The "local" strategy of left atrial appendage closure is noninferior to "systemic" anticoagulation with warfarin. PROTECT AF has, for the first time, implicated the left atrial appendage in the pathogenesis of stroke in atrial fibrillation.

CLINICAL TRIAL REGISTRATION

: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00129545.

Transcatheter Occlusion of the Left Atrial Appendage

The left atrial appendage is a primary source of thrombi in patients with nonvalvular atrial fibrillation. Transcatheter left atrial appendage occlusion/exclusion is a novel technology with the potential as an alternative approach for lifelong anticoagulation to prevent potential catastrophic embolic stroke. This article discusses important evaluation, procedural steps, and the clinical data for left atrial appendage closure.

Cost of atrial fibrillation: invasive vs non-invasive management in 2012

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It places an enormous burden on the patients, caregivers and the society at large. As a chronic illness, AF accrues significant costs related to clinical presentation, complications and loss of productivity. Novel invasive approaches to AF promise a cure in some patients and a significant reduction in AF burden in others, but are very expensive. This paper will address the cost of conventional and invasive strategies in AF care and will review the evidence on the comparative cost effectiveness of these approaches.

Ablation for atrial fibrillation in combination with left atrial appendage closure: first results of a feasibility study

BACKGROUND

Drug-refractory atrial fibrillation (AF) increasingly is being treated with catheter ablation. However, the long-term success rate, expressed as freedom from AF, is <50%. Therefore, vitamin K antagonists, with all their complications, remain necessary. Recently, left atrial appendage (LAA) occlusion devices were introduced as an alternative to vitamin K antagonists. Here, we investigated whether AF ablation and LAA occlusion could be a feasible and safe combination in patients with symptomatic drug-refractory AF and a CHADS(2) score ≥1 or a contraindication for vitamin K antagonists.

METHODS AND RESULTS

Ablation was performed by using multielectrode catheters with phased radiofrequency energy. LAA was occluded with the Watchman device (Atritech, Inc, Plymouth, MN). Between February 2010 and February 2011, 30 patients were treated (21 male; age, 62.8±8.5 years). Median CHADS(2) score was 2.5 (25th to 75th percentiles: 2 to 3), median CHADS-VASc score was 3 (25th to 75th percentiles: 3 to 5), 77% had prior stroke, and 27% had a contraindication for vitamin K antagonists. Median HAS-BLED score was 2 (range, 1 to 5). Successful device implantation was achieved with a median number of 1.5 devices (median diameter 24 mm [25th to 75th percentiles: 24 to 24 mm]). Total procedure time was 97 minutes (25th to 75th percentiles: 75 to 115 minutes). At 60 days, all patients met the criteria for successful sealing. Follow-up visit at 12 months showed a 30% rate of documented recurrence of AF. A repeated pulmonary vein isolation was performed successfully in 4 patients, without interference of the LAA closure device. No thromboembolic events occurred during 1-year follow-up.

CONCLUSION

LAA occlusion with the Watchman device and AF ablation can be combined successfully and safely in a single procedure. The Watchman does not interfere with a repeated ablation.

[Percutaneous exclusion of the left atrial appendage: perspectives]

With its high prevalence and well-known thromboembolic risk, atrial fibrillation (AF) is a crucial component of the 2010-2014 actions plan, ongoing in France to reduce the annual incidence of stroke. The stroke risk is stratified well with the CHA(2)DS(2)-VASc score. With the current guidelines, most patients with AF should be on oral anticoagulant regimen, a treatment recognized as effective but whose bleeding risks limit its use. In clinical practice, warfarin is often not prescribed in patients with high risk of stroke. Thus, the exploration of new ways in preventing thromboembolic events in patients with AF is needed. Beside new more convenient anticoagulant agents, the exclusion of the left atrial appendage recognized as main source of thrombi, may be an alternative in patients with both high risk of thrombotic and haemorrhagic events. Surgical experience showed that the results depend on the quality of the exclusion. For over the past 10 years, several percutaneous exclusion systems of the left atrial appendage have been developed. A randomized study (PROTECT AF) demonstrated the non-inferiority of the percutaneous exclusion in comparison with the warfarin. However, the place of this interventional therapy remains to be clarified, particularly the definition of the target population. This often multidisciplinary approach will have to be accompanied by a reduction of periprocedural complications, increase in rate of complete occlusion, and enough long clinical follow-up to assess the efficiency of this strategy.

Left atrial appendage exclusion for stroke prevention in atrial fibrillation

The public health burden of atrial fibrillation (AF) and associated thromboembolic stroke continues to grow at alarming rates. AF leads to a fivefold increase in the risk of stroke. Therefore, stroke prevention remains the most critical aspect of AF management. Current standard of care focuses on oral systemic anticoagulation, most commonly with warfarin and now with newer agents such as dabigatran, rivaroxaban, and apixaban. However, the challenges and limitations of oral anticoagulation have been well documented. Given the critical role of the left atrial appendage (LAA) in the genesis of AF-related thromboembolism, recent efforts have targeted removal or occlusion of the LAA as an alternative strategy for stroke prevention, particularly in patients deemed unsuitable for oral anticoagulation. This paper highlights recent advances in mechanical exclusion of the LAA. The problem of AF and stroke is briefly summarized, followed by an explanation for the rationale behind LAA exclusion for stroke prevention. After briefly reviewing the history of LAA exclusion, we highlight the most promising LAA exclusion devices currently available. Finally, we discuss future challenges and opportunities in this growing field.

Percutaneous left atrial appendage suture ligation using the LARIAT device in patients with atrial fibrillation: initial clinical experience

OBJECTIVES

The purpose of the study was to determine the efficacy and safety of left atrial appendage (LAA) closure via a percutaneous LAA ligation approach.

BACKGROUND

Embolic stroke is the most devastating consequence of atrial fibrillation. Exclusion of the LAA is believed to decrease the risk of embolic stroke.

METHODS

Eighty-nine patients with atrial fibrillation were enrolled to undergo percutaneous ligation of the LAA with the LARIAT device. The catheter-based LARIAT device consists of a snare with a pre-tied suture that is guided epicardially over the LAA. LAA closure was confirmed with transesophageal echocardiography (TEE) and contrast fluoroscopy immediately, then with TEE at 1 day, 30 days, 90 days, and 1 year post-LAA ligation.

RESULTS

Eighty-five (96%) of 89 patients underwent successful LAA ligation. Eighty-one of 85 patients had complete closure immediately. Three of 85 patients had a ≤ 2-mm residual LAA leak by TEE color Doppler evaluation. One of 85 patients had a ≤ 3-mm jet by TEE. There were no complications due to the device. There were 3 access-related complications (during pericardial access, n = 2; and transseptal catheterization, n = 1). Adverse events included severe pericarditis post-operatively (n = 2), late pericardial effusion (n = 1), unexplained sudden death (n = 2), and late strokes thought to be non-embolic (n = 2). At 1 month (81 of 85) and 3 months (77 of 81) post-ligation, 95% of the patients had complete LAA closure by TEE. Of the patients undergoing 1-year TEE (n = 65), there was 98% complete LAA closure, including the patients with previous leaks.

CONCLUSIONS

LAA closure with the LARIAT device can be performed effectively with acceptably low access complications and periprocedural adverse events in this observational study.

Combined Catheter Ablation for Atrial Fibrillation and Watchman® Left Atrial Appendage Occlusion Procedures: A Single Centre Experience

Background Patients with atrial fibrillation (AF) may be interested in undergoing concomitant interventions of left atrial catheter ablation and device occlusion of the left atrial appendage (LAA). We report on the feasibility and outcome of combined procedures in a single centre case series. Methods Twenty-six patients underwent either first time or redo pulmonary vein isolation (PVI) procedures followed by successful implant of a Watchman^® device. Results All procedures were uncomplicated with a mean case time of 233 ± 38 minutes. Maximal LAA orifice dimension was smaller in 3 of 26 patients post PVI (range 1mm) than on the pre-procedural transoesophageal echocardiogram (TOE). A new peri-device leak of maximum 3mm was noted in 5 of 26 patients at 6 week follow-up TOE, but resolved in 4 by the 6 month follow-up. Conclusion Combined procedures for catheter ablation for AF and Watchman^® LAA implant appear to be feasible and safe with satisfactory occlusion of the LAA maintained at follow-up.

Percutaneous left atrial appendage closure for stroke prevention in atrial fibrillation

BACKGROUND

Percutaneous left atrial appendage (LAA) closure can be an alternative to coumadin treatment in patients with atrial fibrillation (AF) at high risk for thromboembolic events and/or bleeding complications. We report the initial experience with this new technique.

METHODS

Patients were eligible if they had AF with a high stroke risk (CHADS(2) score >1), and/or contraindication for coumadin therapy. The procedure was performed under general anaesthesia, using biplane fluoroscopy and (3D) transoesophageal echocardiography (TEE) guidance. Patients were discharged on coumadin until a TEE was repeated at 45 days after closure to evaluate LAA occlusion. If LAA occlusion was achieved, oral anticoagulation was discontinued and aspirin started.

RESULTS

Percutaneous LAA closure was performed in 10 patients (50% male, age 61.6 ± 9.6 years). The median CHADS(2) score was 3 (range 2-4), median CHA(2)DS(2)-VASc score 3.5 (range 2-6) and HAS-BLED score 1.5 (range 1-4). Nine patients had a history of stroke and 2 patients had a history of major bleeding while on coumadin. Concomitant pulmonary vein isolation was performed in 9 patients. The device was successfully placed in all patients within a median of 56 min (38-137 min). Asymptomatic catheter thrombus occurred in one patient. At 45-day follow-up, no thromboembolic events occurred, TEE showed minimal residual flow in the LAA in three patients. In one patient the LAA device was dislocated, requiring successful percutaneous retrieval.

CONCLUSION

Device closure of the LAA may provide an alternative strategy to chronic coumadin therapy in patients with AF and high risk of stroke and/or bleeding complications using coumadin.

CHADS(2) and CHA(2)DS (2)-VASc score of patients with atrial fibrillation or flutter and newly detected left atrial thrombus

BACKGROUND

The risk of developing a stroke or systemic embolus due to a left atrial (LA) thrombus in patients with atrial fibrillation (AF) and/or atrial flutter (AFL) is estimated by the CHADS(2) score and more recently the CHA(2)DS(2)-VASc score. We aimed to further characterize AF/AFL patients who were found to have a LA thrombus on a transesophageal echocardiogram (TEE).

METHODS AND RESULTS

Of 3,165 TEE between 2005 and 2011 for a broad spectrum of indications, we detected 65 AF patients with LA thrombus (2 %). There were 40 men and 25 women, mean age was 65 ± 13 years (range 36-88 years). Mean CHADS(2) score was 1.8 ± 1.1 and mean CHA(2)DS(2)-VASc score was 3.0 ± 1.6. 11 patients (17 %) had a CHADS(2) score of 0, 12 patients (18 %) of 1, 28 patients (43 %) of 2 and 12 patients (18 %) of 3. Hypertension was the most frequent risk factor (72 %), followed by congestive heart failure (32 %), diabetes (23 %) and age ≥75 years (23 %). Mean difference between CHADS(2) and CHA(2)DS(2)-VASc was 1.25 ± 0.91. Of the 11 patients (17 %) with a LA thrombus despite a CHADS(2) score of 0, five had a CHA(2)DS(2)-VASc score of 0, four a CHA(2)DS(2)-VASc score of 1 and two a CHA(2)DS(2)-VASc score of 2.

CONCLUSION

In an unselected TEE population with newly detected LA thrombus about one-third of patients fell into the low-risk group when classified based on the CHADS(2) score, while a much lower population fell in the same low-risk group when classified according to the CHA(2)DS(2)-VASc score. However, this does not prove clinical superiority of the CHA(2)DS(2)-VASc score over the established CHADS(2) score. Whether our observation has clinical implications (e.g. TEE prior to LA ablation irrespective of CHADS(2) score), or argues for use of the CHA(2)DS(2)-VASc score needs to be evaluated in prospective studies.

Percutaneous Closure of the Left Atrial Appendage

This article reviews the published evidence on stroke prevention with percutaneous closure of the left atrial appendage and provides comparative insight into the various left atrial appendage closure devices currently in development.

Immediate and one-year results in 35 consecutive patients after closure of left atrial appendage with the Amplatzer cardiac plug

INTRODUCTION AND OBJECTIVES

Left atrial appendage closure can be an attractive option for patients with nonvalvular atrial fibrillation and a contraindication to oral anticoagulants, provided that satisfactory results can be achieved during implantation and follow-up.

METHODS

Thirty-five consecutive patients, not eligible for randomized trials with oral anticoagulants, had an Amplatzer occlusion device implanted under general anesthesia. After the first 5 patients, 3-dimensional imaging was incorporated. The results of the implantation and the follow-up were analyzed over a 1-year period.

RESULTS

The mean age was 74.65 (7.61) years, with a CHADS2 score of 2.41 (1.53) and a CHA2DS2-VASc score of 3.17 (1.60). Implantation failed in 1 patient and 5 needed a change in the selected plug size. There were no cardiac complications during the implantation or hospital stay. There was 1 vascular complication (arteriovenous fistula). Transesophageal echocardiography monitoring was performed at 24h, 1, 3, 6, and 12 months and we found 5 thrombi which were resolved with heparin. In the follow-up period of 21.14 (10.09) months, 3 patients aged>80 years died, none of them due to heart problems, and one transient ischemic stroke without further consequences.

CONCLUSIONS

Left atrial appendage closure by an experienced operator can be a treatment option with few complications and with efficient results at>1 year in reducing thromboembolic and hemorrhagic complications, even in very high-risk groups.

Left atrial appendage occlusion: pilot study of a fourth-generation, minimally invasive device

OBJECTIVE

Exclusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The aim of this study was to evaluate the feasibility and efficacy of a fourth-generation atrial exclusion device developed for minimally invasive applications.

METHODS

The novel atrial exclusion device consists of two polymer beams and two elastomeric bands that connect the two beams at either end. Fifteen mongrel dogs were implanted with the device at the base of the left atrial appendage through a median sternotomy and were evaluated at 30 (n = 7), 90 (n = 6), and 180 (n = 2) days after implantation by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histology.

RESULTS

Left atrial appendage exclusion was completed without hemodynamic instability. Coronary angiography revealed that the left circumflex artery was patent in all cases. A new endothelial tissue layer developed, as expected, on the occluded orifice of the left atrium.

CONCLUSIONS

This novel atrial exclusion device achieved easy, reliable, and safe exclusion of the left atrial appendage, with favorable histological results in a canine model for up to 6 months. Clinical application could provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

Atrial fibrillation, stroke, and quality of life

Contemporary management of atrial fibrillation imposes many challenges, particularly in the setting of our aging population. In addition to well-recognized consequences, such as stroke and mortality, emerging evidence relates atrial fibrillation to elevated risk of dementia, posing further therapeutic challenges. As the incidence of atrial fibrillation rises with age, the balance of controlling stroke risk and limiting major hemorrhage on anticoagulation has become increasingly critical in elderly patients. Appreciation of more extensive risk factors has made it possible to identify patients at very low risk of thromboembolism and higher risk of bleeding. However, practice guidelines in the United States and abroad have occasionally divergent viewpoints regarding how to best manage patients in various risk strata. Options for stroke prevention have expanded with novel antithrombotics and promising mechanical alternatives to anticoagulation, which may be at least as effective in preventing stroke without increasing bleeding risk. Catheter ablation has demonstrated impressive success at preventing atrial fibrillation recurrence in selected patients, and has the potential to further improve outcomes. In addition, the role of antiplatelet medications in patients deemed unsuitable for anticoagulation has been better clarified, although novel agents require further study to assess their impact on thromboembolism. High-bleeding risks associated with the concomitant use of multiple antithrombotics remains a major obstacle in patients with indications for both antiplatelet and anticoagulant therapy.

Current Issues in Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It places an enormous burden on the patients, caregivers, and the society at large. While the main themes in the care of an AF patient have not changed over the years and continue to focus on stroke prevention, control of the ventricular, rate and rhythm maintenance, there have been a number of new developments in each of these realms. This paper will discuss the “hot” topics in AF in 2012 including new and upcoming medical and invasive management strategies for this condition.

Current and future alternatives to warfarin for the prevention of stroke in atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice and is associated with a nearly 5-fold increase in the risk of stroke. Warfarin has been the cornerstone of treatment to reduce stroke risk in AF patients for decades. Although effective in preventing thrombosis, warfarin is difficult to manage and is associated with a 1% to 7% yearly risk of major hemorrhage. Until recently, there were no effective oral alternatives to warfarin. Dabigatran etexilate, a direct thrombin inhibitor, was approved in 2010 for the reduction of stroke and systemic embolism in patients with nonvalvular AF, and the factor Xa inhibitor rivaroxaban was approved for a similar indication in 2011. Other late-stage orally administered agents that may be approved for this indication include apixaban and edoxaban; others at earlier stages of development will be discussed in this review as well. Nonpharmacological approaches to stroke prevention include left atrial appendage removal, ligation, or occlusion. This review examines advances in the management of stroke risk in AF patients, focusing on recently marketed and late-stage modalities. The advent of alternatives to warfarin for reducing stroke risk in AF patients may improve physicians' ability to offer safe and effective stroke prevention in all AF patients.

Minimally invasive surgical therapies for atrial fibrillation

Atrial fibrillation is the most common sustained arrhythmia and is associated with significant risks of thromboembolism, stroke, congestive heart failure, and death. There have been major advances in the management of atrial fibrillation including pharmacologic therapies, antithrombotic therapies, and ablation techniques. Surgery for atrial fibrillation, including both concomitant and stand-alone interventions, is an effective therapy to restore sinus rhythm. Minimally invasive surgical ablation is an emerging field that aims for the superior results of the traditional Cox-Maze procedure through a less invasive operation with lower morbidity, quicker recovery, and improved patient satisfaction. These novel techniques utilize endoscopic or minithoracotomy approaches with various energy sources to achieve electrical isolation of the pulmonary veins in addition to other ablation lines. We review advancements in minimally invasive techniques for atrial fibrillation surgery, including management of the left atrial appendage.

Non-pharmacological therapy for atrial fibrillation: managing the left atrial appendage

The prevalence of atrial fibrillation (AF) is increasing in parallel with an ageing population leading to increased morbidity and mortality. The most feared complication of AF is stroke, with the arrhythmia being responsible for up to 20% of all ischemic strokes. An important contributor to this increased risk of stroke is the left atrial appendage (LAA). A combination of the LAA's unique geometry and atrial fibrillation leads to low blood flow velocity and stasis, which are precursors to thrombus formation. It has been hypothesized for over half a century that excision of the LAA would lead to a reduction in the incidence of stroke. It has only been in the last 20-25 years that the knowledge and technology has been available to safely carry out such a procedure. We now have a number of viable techniques, both surgical and percutaneous, which will be covered in this paper.