Left atrial appendage exclusion for atrial fibrillation

Left lateral decubitus computed tomography before catheter ablation in patients with atrial fibrillation

Aim    The study aimed to determine the efficacy of cardiac computed tomography angiography (CCTA) for diagnosing left atrial appendage (LAA) thrombus before catheter ablation with the patient in the left lateral decubitus position and, also, to evaluate the risk factors for thrombus formation.Material and methods    This retrospective, cohort study included 101 patients with atrial fibrillation. All patients underwent transthoracic echocardiography (TTE) and left lateral decubitus CCTA. Transesophageal echocardiography (TEE) was performed to confirm or exclude LAA thrombus. Patients with allergic reactions to iodinated contrast media, increased serum creatinine, hyperthyroidism, pregnancy, and age<18 years were excluded. The CHA2‑DS2‑VASc and HAS-BLED scores were calculated for each patient.Results    All LAA thrombi detected on CCTA were confirmed by TEE. Higher CHA2‑DS2‑VASc, HAS-BLED scores, enlarged LA, and the anteroposterior dimension of the left atrium were significantly associated with the presence of LAA thrombus. A LAA cauliflower shape was a predictor of thrombus. An increase of LAA volume by 1 ml increased the chances of LAA thrombus and cerebral ischemic infarct by 2 %. The growth of the LAA anteroposterior diameter by 1 cm increased the risk of LAA thrombus by 190 % and of cerebral infarct by 78 %. An increase in the CHA2DS2‑VASc score by 1 point increased the risk of thromboembolism and cerebral infarction by 12 %.Conclusions    CCTA performed in the left lateral decubitus position of the patient is an optimal screening tool to detect or exclude LAA thrombus before catheter ablation because of atrial fibrillation. CCTA has predictive value for risk of thrombosis formation in LAA.

Catheter ablation in combined procedures is associated with residual leaks

Objectives

To compare patients with atrial fibrillation (AF) undergoing left atrial appendage closure (LAAC) with catheter ablation (CA) and those without CA.

Background

The CA of AF may cause ridge edema, which may affect the safety of LAAC.

Methods

Patients with AF (N = 98) who underwent LAAC (combined CA + LAAC procedure group; N = 51) or alone (LAAC group; N = 47) received pre-procedural, intra-procedural, and 6 week post-procedural transesophageal echocardiography (TEE). The depth and ostial diameter of LAA, device compression, residual leak, and ridge thickness were evaluated in the patients who had undergone combined and alone procedures, as well as images of LAA and primary clinical characteristics.

Results

A residual leak was identified in 27 patients at 6 weeks after implantation by TEE (19 in the combined procedures group and eight in the alone group; p = 0.04). The combined procedure group had a significantly higher rate of a new residual leak than the alone group (25.5 vs. 8.5%; p = 0.03). Meanwhile, compared with at the time of implant, a smaller amount of device compression ratio was significant after 6 weeks (22.44 ± 3.90 vs. 19.59 ± 5.39; p = 0.03). There was no significant difference between both groups in all-cause mortality, cardiovascular mortality, and TIA/stroke/system embolism.

Conclusion

The combined procedures of CA and LAAC for AF are feasible and safe; however, during the follow-up period, we found that the resolution of ridge edema caused by CA might cause an increased residual leak and a smaller device compression ratio.

The first experience of a hybrid approach in the surgical treatment of atrial fibrillation

Background: Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with an increased risk of death, progression of heart failure, and the development of cardiogenic thromboemboli. Despite the significant success in the management of AF in the paroxysmal form, the results of the treatment for patients with persistent forms of AF remain unsatisfactory. Though the surgical approach provides higher rates of efficiency regarding the restoration of a sinus rhythm, transmural lesions are not always attainable, as a result, the rate of AF recurrence in the long-term period remains fairly high. It is also impossible to create ablative patterns to the mitral and tricuspid valves during thoracoscopic epicardial ablation, which can cause the development of recurrent AF, perimitral and typical atrial flutter. Therefore, the development of hybrid approaches combining the advantages of catheter and thoracoscopic techniques is an urgent task of contemporary surgical and interventional arrhythmology. Aims: to estimate the immediate results of a hybrid approach in the management of patients with persistent AF. Methods: We report the first experience of a hybrid treatment of patients with persistent AF. 6 patients aged 53-64 years (1 female, 5 males) were included in the study. At the first stage, thoracoscopic epicardial bipolar ablation was performed (modified GALAXY protocol); the second stage (in 3 to 6 months after the thoracoscopic stage) included an intracardiac electrophysiological study with three-dimensional endocardial mapping followed by endocardial ablation. Results: The thoracoscopic stage of the hybrid treatment included ablation according to the box lesion scheme using a bipolar irrigation equipment. No lethal outcomes and severe, life-threatening complications were registered. The duration of the inpatient period was 510 hospital-days. The 2nd stage of the hybrid treatment was limited to intracardiac electrophysiological examination only in 2 patients. In 4 patients, epicardial radiofrequency ablation was complemented by endocardial radiofrequency exposure. In 3 of the 4 patients who underwent endocardial radiofrequency ablation, catheter ablation of the mitral and cavotricuspid isthmus was required because of the induction of perimitral and typical flutter, respectively. After the 2nd stage of the hybrid treatment, at the time of discharge all the patients maintained a stable sinus rhythm. There were no severe complications or lethal outcomes. Conclusion: a hybrid approach in the AF management is a safe and effective method of treatment, which combines the advantages of minimally invasive surgery and endocardial intervention in patients with persistent AF. The technique is safe and has acceptable short-term results.

Safety and efficacy of the Amplatzer amulet and watchman2.5 for left atrial appendage occlusion: a Systematic review and meta-analysis

BACKGROUND

Left atrial appendage occlusion (LAAO) is an alternative to oral anticoagulation (OAC) to decrease the risk of stroke in patients with nonvalvular atrial fibrillation (NVAF); however, certain complications remain a concern. Amplatzer Amulet and Watchman are the two most popular used devices for preventing stroke in patients with NVAF. We assessed the safety and efficacy of LAAO using the Amplatzer Amulet and Watchman.

METHODS

A meta-analysis was conducted to compare the safety and efficacy outcomes associated with the use of the Amplatzer Amulet and Watchman 2.5. The Newcastle-Ottawa Scale has been utilized to assess the quality of study.

RESULTS

The meta-analysis includes seven studies involving 2,926 patients (1,418 patients with an amulet and 1,508 with a Watchman 2.5). Generally, adverse event rates for both systems were minimal. No significant differences between the two devices were found in safety (pericardial effusion, device embolization, and cardiac tamponade) or efficacy outcomes (death, TIA, stroke, major/minor bleeding, device leak, and thromboembolic events).

CONCLUSIONS

The data suggest LAAO is a safe procedure, regardless of which device was used. LAAO devices generally have low complication rates. Outcomes were comparable between the two groups with no significant differences in their safety or efficacy. This article is protected by copyright. All rights reserved.

Atrial Fibrillation and Ventricular Tachyarrhythmias: Advancements for Better Outcomes

Cardiac arrhythmias are associated with several cardiac diseases and are prevalent in people with or without structural and valvular abnormalities. Ventricular arrhythmias (VA) can be life threating and their onset require immediate medical attention. Similarly, atrial fibrillation and flutter lead to stroke, heart failure and even death. Optimal treatment of VA is variable and depends on the medical condition associated with the rhythm disorder (which includes reversible causes such as myocardial ischemia or pro-arrhythmic drugs). While an implanted cardioverter defibrillator is often indicated in secondary prevention of VA. This review highlights the newest advancements in these techniques and management of ventricular and atrial tachyarrhythmias, along with pharmacological therapy.

Role of Different Antithrombotic Regimens after Percutaneous Left Atrial Appendage Occlusion: A Large Single Center Experience

BACKGROUND

Optimal antithrombotic therapy after left atrial appendage (LAA) occlusion is still not clear. The aim of this study was to investigate the role of different antithrombotic regimens after the procedure.

METHODS AND RESULTS

We retrospectively analyzed data of 260 patients who underwent LAA occlusion and divided them into four groups according to therapy at discharge: dual antiplatelet therapy (group A, 71.5%); oral anticoagulants (group B, 19%); "minimal" antithrombotic therapy (single antiplatelet agent or without any antithrombotic therapy; group C, 4.5%) and other therapeutic regimens (such as a combination of antiplatelets and anticoagulants; group D, 4.5%). We analyzed baseline characteristics, procedural data, and clinical and transesophageal follow-up for each group. The incidence of adverse events was low in the whole population and had a similar distribution among groups. The majority of bleeding events was registered during the first 3 months after the procedure (34 out of 46, 70%). Ischemic events (2%), as well as silent left atrial thrombosis, were rare and not significantly higher in the population discharged with "minimal" antithrombotic therapy.

CONCLUSION

Our experience seems to suggest that LAA occlusion was associated with a low incidence of adverse events, regardless of antithrombotic therapy. A "minimal" drug regimen may be feasible without losing efficacy on embolic prevention for patients with high bleeding risk.

The relationship between incomplete surgical obliteration of the left atrial appendage and thromboembolic events after mitral valve surgery (from the ISOLATE Registry)

Left atrial appendage (LAA) is a common site of thrombus formation especially in patients with atrial fibrillation (AF). Complete surgical LAA closure (cSLC) is the surgical aim, however incomplete surgical LAA closure (iSLC) is not rare. In this study, we aimed to evaluate the risk of thromboembolic complications (TEC) in AF patients with iSLC after mitral valve surgery. A total of 101 AF patients (mean age: 61.8 ± 11.8 years; male:32), who underwent surgical suture ligation during mitral valve surgery were enrolled in this retrospective study. All patients underwent transthoracic and transesophageal echocardiography (TEE) at least 3 months after surgery. The primary outcome was the occurrence of TEC including any ischemic stroke, transient ischemic attack, coronary or peripheral embolism. TEE examination revealed cSLC in 66 (65.3%) and iSLC in 35 patients (34.6%). A total of 12 TECs (11.9%) occurred during a mean follow-up time of 41.1 ± 15.6 months. TECs were found to be significantly higher in the iSLC group (25.7% vs 4.5%, p = 0.002). The prevalence of iSLC was significantly higher in patients with TEC (75 vs. 29.2%, p = 0.002). High CHA₂DS₂-VASc Score and iSLC were found to be independent predictors of TEC. Long term TEC free survival was found to be significantly decreased in patients with iSLC. The presence of iSLC was associated with a significantly increased risk of TEC in AF patients after mitral valve surgery. Routine intraoperative and postoperative screening for iSLC by TEE and long-term strict anticoagulation therapy are recommended in these patients.

Incomplete Closure of the Left Atrial Appendage: Implication and Management

Incomplete left atrial appendage closure (LAAC) occurs in ∼30-40 % of cases following both surgical and percutaneous closure methods. Incomplete surgical LAAC may further be classified as incompletely surgically ligated LAA (ISLL) or LAA stump. ISLL is associated with a significantly increased risk of thrombus formation/thromboembolism. Moreover, this risk is highest in the absence of oral anticoagulation (OAC) and inversely correlates with the size of the ISLL neck. Not only routine screening for ISLL seems critical, but also long-term OAC should strongly be considered in this high-risk cohort. Alternatively, complete endocardial occlusion using a surrogate method may represent a reasonable option, particularly in those intolerant to long-term OAC therapy. Although thrombus formation/thromboembolic events have also been described in patients with incomplete LAAC following percutaneous occlusion, an association between the two remains less clear. However, given the rise and growing interest in percutaneous LAAC methods, additional research in this area is clearly warranted.

Pneumatic Burst Pressures After Inverted Closure of the Left Atrial Appendage: An Ex Vivo Model

BACKGROUND

The left atrial (LA) appendage (LAA) is the main source of thromboembolism in atrial fibrillation. This study addressed initial pressure resistance of surgical LAA closures.

METHODS

In an experimental model, pneumatic pressure resistances of different surgical closure techniques were examined, and variations in technique and access were studied. In preparations of the LA from freshly slaughtered pigs, pneumatic pressure was applied to the LAA. Burst pressures (mbar) of various closure techniques (n = 12 specimens per group) were measured: (1) epicardial double-layer suture, (2) epicardial stapler closure (staple height 2 mm), (3) epicardial stapler closure (staple height 4, 4.5, and 5 mm), (4) endocardial inverse double-layer suture, (5) endocardial inverse stapler seam (staple height 2 mm), and (6) endocardial inverse stapler seam (staple height 4, 4.5, and 5 mm).

RESULTS

The mean burst pressure in group 1 was 175.5 ± 19.35 mbar. There was no significant difference compared with group 2 (174.5 ± 28.45 mbar) or group 3 (176 ± 27.69 mbar). Group 4 scored significantly higher than all other groups (198.9 ± 18.35 mbar). Burst pressures in group 5 (136.2 ± 16.68 mbar) were significantly lower than in group 4 and in group 6 (165.1 ± 21.94 mbar), but the differences between groups 5 and 6 were also significant.

CONCLUSIONS

In an ex vivo model, double-layer suturing of the inverted LAA from an internal LA access led to higher burst pressures compared with epicardial suturing and with both endocardial and epicardial stapled closures.

Left atrial appendage closure: A single center experience and comparison of two contemporary devices

OBJECTIVES

To compare indications and clinical outcomes of two contemporary left atrial appendage (LAA) percutaneous closure systems in a "real-world" population.

BACKGROUND

Percutaneous LAA occlusion is an emerging therapeutic option for stroke prevention in atrial fibrillation. Some questions however remain unanswered, such as the applicability of results of randomized trials to current clinical practice. Moreover, currently available devices have never been directly compared.

METHODS

We retrospectively analyzed consecutive patients who underwent LAA closure at San Raffaele Hospital, Milan, Italy between 2009 and 2015. Clinical indications and device selection were left to operators' decision; routine clinical and transesophageal echocardiography (TEE) follow-up was performed.

RESULTS

One-hundred and sixty-five patients were included in the study, of which 99 were treated with the Amplatzer Cardiac Plug (ACP) and 66 with the Watchman system. During the follow-up period (median 15 months, interquartile range 6-26 months) five patients died. The incidence of ischemic events was low, with one patient suffering a transient ischemic attack and no episodes recorded of definitive strokes. Twenty-six leaks ≥1 mm were detected (23%); leaks were less common with the ACP and with periprocedural three-dimensional TEE evaluation, but were not found to correlate with clinical events. Clinical outcomes were comparable between the two devices.

CONCLUSIONS

Our data show excellent safety and efficacy of LAA closure, irrespectively of the device utilized, in a population at high ischemic and hemorrhagic risk. The use of ACP and 3D-TEE minimized the incidence of residual leaks; however, the clinical relevance of small peri-device flow warrants further investigation. © 2016 Wiley Periodicals, Inc.

Left Atrial Appendage Closure for Stroke Prevention: Devices, Techniques, and Efficacy

Left atrial appendage closure can be performed either surgically or percutaneously. Surgical approaches include direct suture, excision and suture, stapling, and clipping. Percutaneous approaches include endocardial, epicardial, and hybrid endocardial-epicardial techniques. Left atrial appendage anatomy is highly variable and complex; therefore, preprocedural imaging is crucial to determine device selection and sizing, which contribute to procedural success and reduction of complications. Currently, the WATCHMAN is the only device that is approved for left atrial appendage closure in the United States.

Electrophysiological Perspectives on Hybrid Ablation of Atrial Fibrillation

To overcome limitations of minimally invasive surgical ablation as a standalone procedure in eliminating atrial fibrillation (AF), hybrid approaches incorporating adjunctive endovascular catheter ablation have been proposed in recent years. The endovascular component targets residual conduction gaps and identifies additional electrophysiological targets with the goal of minimizing recurrent atrial arrhythmia. We performed a systematic review of published studies of hybrid AF ablation, analyzing 432 pooled patients (19% paroxysmal, 29% persistent, 52% long-standing persistent) treated using three different approaches: A. bilateral thoracoscopy with bipolar radiofrequency (RF) clamp-based approach; B. right thoracoscopic suction monopolar RF catheter-based approach; and C. subxiphoid posterior pericardioscopic ("convergent") approach. Freedom from recurrence off antiarrhythmic medications at 12 months was seen in 88.1% [133/151] for A, 73.4% [47/64] for B, and 59.3% [80/135] for C, with no significant difference between paroxysmal (76.9%) and persistent/long-standing persistent AF (73.4%). Death and major surgical complications were reported in 8.5% with A, 0% with B and 8.6% with C. A critical appraisal of hybrid ablation is presented, drawing from experiences and insights published over the years on catheter ablation of AF, with a discussion of the rationale underlying hybrid ablation, its strengths and limitations, where it may have a unique role in clinical management of patients with AF, which questions remain unanswered and areas for further investigation.