Surgical clip closure of the left atrial appendage

Outcomes After Left Atrial Appendage Clip Placement During Cardiac Surgery: A Nationwide Analysis

This study evaluated the nationwide associations between concomitant left atrial appendage clip (LAAC) placement during cardiac surgery and postoperative outcomes. We identified 1,260,999 patients who underwent coronary artery bypass grafting, valve, and aortic surgeries in the 2016 to 2020 Nationwide Readmissions Database and stratified by concomitant LAAC versus no LAAC placement. Patients who underwent surgical ablation were excluded. Mortality and complications were compared during index admissions and for patients readmitted within 30 and 90 days of the index discharge date for unmatched and propensity score-matched groups. Overall, 6.7% (84,293) of patients underwent cardiac surgery and concomitant LAAC placement without surgical ablation. After propensity score matching, the index admission mortality and overall complications were not different in patients with LAAC versus patients without LAAC. LAAC placement was associated with increased any-cause 30-day readmissions (15% vs 13%, p <0.01). In patients with LAAC, within 30 days, there were no differences in mortality (3.9% vs 3.8%, p = 0.60) or overall complications (64% vs 63%, p = 0.20), whereas stroke was lower (5.3% vs 6.5%, p <0.01) and heart failure was higher (35% vs 30%, p <0.01). For patients readmitted within 90 days, similar findings were observed for any-cause readmissions, mortality, overall complications, stroke, and heart failure. In conclusion, concomitant LAAC placement during cardiac surgery was associated with lower early postdischarge incidence of stroke and a favorable overall risk-benefit profile. Given these short-term findings in a real-world population of all patients who underwent cardiac surgery, longer-term studies with more granular data are needed to evaluate the potential benefit of this practice.

Surgical options for atrial fibrillation treatment during concomitant cardiac procedures

Current guidelines recommend concomitant surgical ablation (SA) of atrial fibrillation (AF) in the context of mitral valve disease. A variety of energy sources have been tested for SA to perform effective transmural lesions reliably. To date, only radiofrequency and cryothermy energies are considered viable options. The gold standard for SA is the Cox-Maze ablation set, especially for non-paroxysmal AF (nPAF), with the aim of interrupting macro-reentrant drivers perpetuating AF, without hampering the sinus node activation of both atria, and to maintain the atrioventricular synchrony. Although the efficacy of SA in terms of early and late sinus rhythm restoration has been clearly demonstrated over the years, concomitant AF ablation is still underperformed in patients with AF undergoing cardiac surgery. From a surgical standpoint, concerns have been raised about whether a single (left) or double atriotomy would be justified in AF patients undergoing a "non-atriotomy" surgical procedure, such as aortic valve or revascularization surgery. Thus, an array of simplified lesion sets have been described in the last decade, which have unavoidably hampered procedural efficacy, somewhat jeopardizing the standardization process of ablation surgery. As a matter of fact, the term "Maze" has improperly become a generic term for SA. Surgical interventions that do not align with the principles of forming conduction-blocking lesions according to the Maze pattern, cannot be classified as Maze procedures. In this complex scenario, a tailored approach according to the different AF patterns has been proposed: for patients with concomitant nPAF, a biatrial Cox-Maze ablation is recommended. Conversely, it might be reasonable to limit lesions to the left atrium or the pulmonary veins in patients with paroxysmal AF (PAF) in some clinical scenarios. The aim of this review is to provide an overview of the current ablation strategies for patients with AF undergoing concomitant cardiac surgery.

Novel sizing role of 3D transesophageal echocardiography in a novel left atrial appendage clip device for patients undergoing video-assisted atrial fibrillation ablation: a cohort study

Background

Three-dimensional (3D) transesophageal echocardiography (TEE) has been successfully used in the sizing of left atrial appendage (LAA) occlusion devices, but its use has not yet been studied in LAA clip devices. We sought to develop and validate the novel use of 3D-TEE sizing in a novel LAA clip device for atrial fibrillation (AF) patients undergoing video-assisted thoracic surgery (VATS) ablation.

Methods

Consecutive patients with isolated AF undergoing LAA clipping or excision during VATS ablation were included in the study between June 2021 and September 2022 at Fuwai Hospital. The patients underwent 3D-TEE examinations preoperatively and postoperatively. The VATS length, LAA clip effective length, and LAA excision margin length were recorded. A correlation analysis, intraclass correlation coefficient (ICC) analysis, and Bland-Altman plot analysis were conducted to examine the TEE parameters, VATS length, LAA clip effective length, and LAA excision margin length.

Results

In total, 26 AF patients undergoing LAA clipping and 15 undergoing LAA excision were included in the study. In the LAA clipping group, in which the Atriclip size served as the control, the 3D-TEE with volumetric measurement (the perimeter-derived maximum orifice diameter) (R=0.938; ICC =0.934; Bland-Altman plot variability, 3.85%) showed the best sizing efficacy for the LAA clip device among the 3D-TEE with multiplanar reformatting sizing (the perimeter-derived maximum orifice diameter) (R=0.808; ICC =0.772; Bland-Altman plot variability, 3.85%), VATS sizing (R=0.851; ICC =0.756; Bland-Altman plot variability, 11.54%), and VATS plus 0.5-cm sizing (R=0.851; ICC =0.775; Bland-Altman plot variability, 11.54%) measurements (all P<0.001). In addition, for the distribution of matched sizing in the LAA clip group, 3D-TEE with volumetric measurement sizing (20/26) had a higher proportion than 3D-TEE with multiplanar reformatting sizing (11/26, P=0.011), VATS sizing (9/26, P=0.002), and VATS plus 0.5-cm sizing (14/26, P=0.08). Using the LAA excision margin length as the control, the mean difference in the LAA diameter was 1.17 cm [95% confidence interval (CI): 0.71-1.62 cm , P<0.001] in the maximum orifice diameter of two-dimensional-TEE, 0.15 cm (95% CI: -0.32 to 0.61 cm , P=0.523) in the perimeter-derived 3D multiplanar reformatting (the maximum orifice diameter), and 0.03 cm (95% CI: -0.47 to 0.53, P=0.901) in the perimeter-derived 3D volumetric (3DV) measurement (the maximum orifice diameter), and the related Pearson correlation coefficients for these modalities were 0.760 (P=0.001), 0.843 (P<0.001), and 0.963 (P<0.001), respectively.

Conclusions

Our study showed that 3D-TEE might be employed in the sizing of a novel LAA clip device using the VATS approach in patients with AF. The 3DV measurement (the perimeter-derived maximum orifice diameter) was superior to the VATS measurement. These findings might also apply to LAA VATS excision patients with AF.

Hybrid strategies for stand-alone surgical ablation of atrial fibrillation

Atrial fibrillation (AF) has been reported as a major cause of cardiac morbidity and mortality, and significantly reduces the quality of life in symptomatic patients. Current guidelines recommend antiarrhythmic drugs and catheter ablation (CA) as first-line therapy. Despite CA showed to be associated with lower incidence of peri-procedural complications, rhythm outcomes are far from optimal. Indeed, patients undergoing CA frequently require multiple AF ablation procedures, especially in those with persistent and long-standing persistent AF. While surgical ablation can provide transmural lesions, surgical invasiveness has limited the widespread use of this approach due to the increased perioperative complications. The development of minimally invasive thoracoscopic approaches has renewed the interest towards surgical ablation, thus favoring more simplified ablation sets. Therefore, the concept of "hybrid" ablation has emerged in order to theoretically enhance advantages of both minimally invasive and CA procedures while seeking to improve rhythm outcomes and reduce invasiveness and incidence of perioperative complications. On one hand, it provides the effectiveness of a surgical ablation, on the other, electrical mapping during CA can identify and treat any ablation gap or provide additional ablation lines, thus improving the chance of a stable sinus rhythm restoration at long-term follow-up. Three main thoracoscopic strategies are currently available. All of them can be performed in conjunction with the "catheter ablation procedure": the "Fusion" technique, the bipolar clamp technique, and the most recent "convergent" technique. CA can be performed either simultaneously or with a staged approach after a blanking period in order to allow the ablation lesion to stabilize. Excellent results of the hybrid procedures have been reported in terms of rhythm outcomes and incidence of perioperative complications. This narrative review aims to discuss the rationale behind the concept of hybrid ablation for the treatment of AF regarding different available strategies, results and expert opinions.

Stroke Prevention in Atrial Fibrillation: Our Current Failures and Required Research

Nonvalvular atrial fibrillation is a common rhythm disorder of middle-aged to older adults that can cause ischemic strokes and systemic embolism. Lifelong use of oral anticoagulants reduces the risk of these ischemic events but increases the risk of major and clinically relevant hemorrhages. These medications also require strict compliance for efficacy, and they have nontrivial failure rates in higher-risk patients. Left atrial appendage closure is a nonpharmacological method to prevent ischemic strokes in atrial fibrillation without the need for lifelong anticoagulant use, but this procedure has the potential for complications and residual embolic events. This workshop of the Roundtable of Academia and Industry for Stroke Prevention discussed future research needed to further decrease the ischemic and hemorrhagic risks among patients with atrial fibrillation. A direct thrombin inhibitor, factor Xa inhibitors, and left atrial appendage closure are FDA-approved approaches whereas factor XIa inhibitors are currently being studied in phase 3 randomized controlled trials for stroke prevention. The benefits, risks, and shortcomings of these treatments and future research required in different high-risk patient populations are reviewed in this consensus statement.

Thoracoscopic Surgical Ablation of Lone Atrial Fibrillation: Long-term Outcomes at 7 Years

BACKGROUND

Antiarrhythmic drugs and transcatheter ablation in atrial fibrillation (AF) provide suboptimal rhythm control with a not negligible rate of failure in paroxysmal AF (PAF) and nonparoxysmal AF (n-PAF) at midterm and long-term follow-up. This study evaluated the safety profile and long-term efficacy of thoracoscopic ablation in patients with lone AF.

METHODS

A consecutive 153 patients with lone AF were prospectively enrolled and underwent thoracoscopic surgical ablation. Inclusion criteria were symptomatic AF refractory to pharmacologic therapy (Vaughan-Williams class I-III), age >18 years, and absence of left atrial thrombosis. Exclusion criteria were long-standing AF >5 years, left atrial diameter >55 mm, and contraindication to oral anticoagulation. The "box lesion set" (encircling of pulmonary veins) was always used. Exclusion of the left atrial appendage was performed only in selected cases. The primary study end point was freedom from AF. Secondary end points were overall survival and cumulative incidence function of cardiac event-related death, cerebrovascular accidents, and pacemaker implantation.

RESULTS

There was no in-hospital mortality. Early postoperative complications were pacemaker implantation (4/153 [2.6%]), cerebrovascular accident (2/153 [1.3%]) with full recovery of both, and bleeding requiring surgical revision (2/153 [1.3%]). Overall freedom from AF at 7 years was 86% ± 4% (76.9% in n-PAF, 96.1% in PAF). Survival freedom from AF in patients without antiarrhythmic drugs in PAF and n-PAF groups was 79.1% and 52.2%, respectively.

CONCLUSIONS

Thoracoscopic surgical ablation of lone AF by means of an isolated left atrial box lesion provided an excellent long-term rhythm outcome, even in long-standing persistent AF. The isolated left atrial ablation showed an excellent safety profile with low incidence of pacemaker implantation and postoperative complications.

Clinical Effectiveness and Safety Comparison between Reduced Rivaroxaban Dose and Dual Antiplatelet Therapy for Nonvalvular Atrial Fibrillation Patients Following Percutaneous Left Atrial Appendage Closure: A Prospective Observational Study

Background

Device-related thrombosis (DRT) after successful closure implantation on left atrial appendage (LAA) was considered as a major challenge and optimal strategy on antithrombotic therapy remains to be solved. This study was performed to compare the clinical effectiveness and safety of reduced rivaroxaban dose (RRD) and dual antiplatelet therapy (DAPT) after left atrial appendage closure (LAAC) implantation with the Watchman device.

Methods

After successful LAAC, consecutive participants were medicated with a standard DAPT or RRD. The primary endpoints included DRT, thrombosis events (TE), and bleeding events that were documented during a 12-month follow-up period.

Results

767 patients (DAPT: n = 140; RRD: n = 627) were initially included. After propensity score matching (PSM), 140 patients treated with DAPT and 280 patients with RRD were included in each group with similar baseline information, thromboembolic and bleeding risk factors, cardiovascular risk factors and concomitant medication. In the RRD group, 193 patients were on rivaroxaban 15 mg ( R 15 ) and 47 received rivaroxaban 10 mg ( R 10 ). The incidence of DRT was documented in 12 (9.3%) patients in the DAPT group and 3 (6.3%) in R 10 and 7 (3.0%) in R 15 (log-rank p = 0.050). DAPT subgroups were more likely to experience shorter time to DRT as compared to R 15 ( R 15 vs. DAPT hazard ratio (HR) = 0.334, p = 0.015, 95% CI: 0.131-0.850). The median length of DRT in the R 15 group was significantly lower than that of the DAPT group (1.721 [1.610-1.818] mm vs. 1.820 [1.725-1.925] mm, p = 0.029). Compared with the unadjusted estimated rates of ischemic events for patients with similar congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category ( CHA 2 DS 2 - VAS c ) scores, a significant decrease of 68.6% in ischemic stroke rates was noted in the R 15 group, which contributed to a 54.9% reduction of overall thromboembolic events. The overall minor bleeding was not significantly different amongst the three groups (p = 0.944). Procedural bleeding was more common in the DAPT group, as compared with the R 10 and R 15 groups.

Conclusions

After successful closure implantation, long-term RRD significantly reduced the DRT and TE occurrence compared with DAPT.

A highly-detailed anatomical study of left atrial auricle as revealed by in-vivo computed tomography

The left atrial auricle (LAA) is the main source of intracardiac thrombi, which contribute significantly to the total number of stroke cases. It is also considered a major site of origin for atrial fibrillation in patients undergoing ablation procedures. The LAA is known to have a high degree of morphological variability, with shape and structure identified as important contributors to thrombus formation. A detailed understanding of LAA form, dimension, and function is crucial for radiologists, cardiologists, and cardiac surgeons. This review describes the normal anatomy of the LAA as visualized through multiple imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and echocardiography. Special emphasis is devoted to a discussion on how the morphological characteristics of the LAA are closely related to the likelihood of developing LAA thrombi, including insights into LAA embryology.

Percutaneous Left Atrial Appendage Occlusion Therapy: Evolution and Growing Evidence

Atrial fibrillation (AF) is the most common cardiac arrhythmia and if untreated, significantly increases both the risk of intracardiac thrombus formation and ischemic stroke. In patients with nonvalvular AF (NVAF), the left atrial appendage (LAA) has been estimated to be the source of thrombus development in 91% to 99% of cases. Consequently, oral anticoagulation (OAC) to provide stroke prevention has become the standard of care for most AF patients; however, OACs are associated with a risk of bleeding and their efficacy depends on optimal patient compliance. In terms of alternative approaches to preventing embolic events, surgical LAA excision was attempted as early as in the late 1940s in patients with valvular AF; LAA excision remains a recommendation in surgical guidelines for NVAF patients who need open-heart coronary bypass or valvular replacement/repair surgeries. However, due to its invasive nature surgical LAA intervention has limited clinical application in present cardiology practice. Percutaneous LAA occlusion (LAAO) is increasingly being performed as an alternative to OAC for stroke prevention; this is particularly the case in patients at increased bleeding risk. Substantial progress has been made in percutaneous LAAO therapy since its inception some twenty years ago. Herein we systematically review both the critical literature that led to the development of LAAO, and the increasing clinical evidence supporting the application of this treatment strategy in NVAF. To this end we focus on recently published critical evaluations of United States Food and Drug Administration (US FDA) and Conformité Européenne (Commercial Sale of Licensed Product in the EU) (CE-Mark) approved LAAO devices, summarize the current status of LAAO therapy, and discuss the future perspectives regarding the knowledge and technology gaps in this area by recognizing the potential contributions of many ongoing but likely transformative clinical trials.

Rhythm outcomes of minimally-invasive off-pump surgical versus catheter ablation in atrial fibrillation: A meta-analysis of reconstructed time-to-event data

BACKGROUND

Mid- and long-term rhythm outcomes of catheter ablation (CA) for atrial fibrillation (AF) are reported to be suboptimal. Minimally invasive surgical off-pump ablation (MISOA), including both thoracoscopic and trans-diaphragmatic approaches, has been developed to reduce surgical invasiveness and overcome on-pump surgery drawbacks. We sought to compare the efficacy and safety of MISOA and CA for AF treatment.

METHODS

A systematic review and meta-analysis of the literature was performed including studies comparing MISOA and CA. The primary endpoint was survival freedom from AF at follow-up after a 3-month blanking period. Subgroup analysis of the primary endpoint was performed according to the type of surgical incision and hybrid approach.

RESULTS

Freedom from AF at 4 years was 52.1% ± 3.2% vs 29.1% ± 3.5%, between MISOA and CA respectively (log-rank p < 0.001; Hazard Ratio: 0.60 [95%Confidence Interval (CI):0.50-0.72], p < 0.001). At landmark analysis, a significant improvement in rhythm outcomes was observed in the MISOA group after the 5th month of follow-up (2 months from the blanking period). The Odds Ratio between MISOA and CA of postoperative cerebrovascular accident incidence and postoperative permanent pacemaker implant (PPM) were 2.00 (95%CI:0.91-4.40, p = 0.084) and 1.55 (95%CI:0.61-3.95, p = 0.358), respectively. The incidence rate ratio of late CVA between MISOA and CA was 0.86 (95%CI:0.28-2.65, p = 0.787), while for late PPM implant was 0.45 (95%CI:0.11-1.78, p = 0.256).

CONCLUSIONS

The current meta-analysis suggests that MISOA provides superior rhythm outcomes when compared to CA in terms of sinus rhythm restoration. Despite the rhythm outcome superiority of MISOA, it is associated to higher postoperative complications compared to CA.

The role of cardiac imaging before and after left atrial appendage standalone thoracoscopic exclusion

AIMS

To assess the characteristics of left atrial appendage (LAA) stump and left atrial (LA) volume after standalone totally thoracoscopic LAA exclusion in 40 patients with nonvalvular atrial fibrillation (NVAF) and contraindications to oral anticoagulation (OAC), using cardiac computed tomography (CCT) and transoesophageal echocardiography (TOE).

METHODS

Using CCT and TOE, we evaluated correct AtriClip Pro II positioning, the presence and characteristics of the LAA stump and the postprocedural LA volume, at 3 months' follow-up. Stump depth was measured with both CCT and TOE using a new method, based on left circumflex artery (LCX) course.

RESULTS

After placement of AtriClip, all 40 patients discontinued OAC, and no stroke occurred. LAA exclusion was achieved in 40/40 patients at 3 months' follow-up. LAA stump (depth <10 mm in 12/18 stump, 67%) was observed in 18 patients. The overall (LA + LAA) volume and isolated LA volume were statistically different when comparing cases with and without LAA stump (P < 0.02). LAA ostium dimensions (perimeter and area) and LAA volume correlate with stump depth (P < 0.02). There was a high correlation between CCT and TOE in stump identification and depth measurement (P < 0.02). Compared with the baseline, CCT LA volume increased (P < 0.01) at 3 months' follow-up.

CONCLUSION

Preprocedural and postprocedural CCT and TOE are useful and comparable in patients undergoing standalone totally thoracoscopic exclusion of LAA, because these imaging methods can identify anatomical LAA and LA characteristics predisposing for a postprocedural residual stump.

Atrioventricular node ablation and pacing for atrial tachyarrhythmias: A meta-analysis of postoperative outcomes

BACKGROUND

Atrioventricular node ablation (AVNA) and pacemaker (PM) is performed in symptomatic atrial fibrillation (AF) unresponsive to medical treatment and percutaneous ablation. This meta-analysis evaluated results after AVNA and PM.

METHODS

Primary and secondary endpoints were early/late overall/cardiac-related mortality and early/late postoperative complications. Meta-regression explored mortality and preoperative characteristics relation.

RESULTS

We selected 93 studies with 11,340 patients: 9105 right ventricular (RV)-PM, and 2235 biventricular PM (cardiac resynchronization therapy, CRT). Malignant arrhythmia (2.5%), heart failure (2.4%), and lead dislodgement (2.0%) were most common periprocedural complications. Pooled estimated 30-day mortality was 1.08% (95%CI:0.65-1.77). At 19.9 months median follow-up (IQR: 10.3-34 months), rehospitalization (0.79%/month) and heart failure (0.48%/month) were the most frequent complications. Overall mortality incidence rate (IR) was 0.43%/month (95%CI:0.36-0.51), and cardiac death IR 0.27%/month (95%CI:0.22-0.32). No mortality determinants emerged in the AVNA CRT subgroup. AVNA RV-PM subgroup univariable meta-regression showed inverse relationship between age, ejection fraction (EF), and late cardiac death (Beta = -0.0709 ± 0.0272; p = 0.0092 and Beta = -0.0833 ± 0.0249; p = 0.0008). Coronary artery disease (CAD) was directly associated to follow-up overall/cardiac mortality at univariable (Beta = 0.0550 ± 0.0136, p < 0.0001; Beta = 0.0540 ± 0.0130, p < 0.0001) and multivariable (Beta = 0.0460 ± 0.0189, p = 0.152; Beta = 0.0378 ± 0.0192, p = 0.0491) meta-regression.

CONCLUSIONS

Solid long-term evidence supporting AVNA and pace is lacking. Younger patients with reduced LVEF% have increased follow-up cardiac mortality after AVNA RV and may require CRT. Alternative strategies to maintain sinus rhythm and ventricular synchronism should be compared to AVNA to support future treatment strategies.

Left Atrial Appendage Closure: A Current Overview Focused on Technical Aspects and Different Approaches

Several studies in literature have shown that 90% of emboli related to non-valvular atrial fibrillation originate from left atrial appendage. Percutaneous closure or surgical exclusion of left atrial appendage in patients with high bleeding and high cardioembolic risk is currently a well established procedure in literature, clinical practice and guidelines. Knowledge of different techniques of left atrial appendage closure is necessary to individualize the procedure according to the patient anatomy and pre-procedural imaging evaluations. In this review the authors will evaluate different left atrial appendage closure systems and the different pre and intra procedural imaging methods.