Left atrial appendage occlusion: rationale, evidence, devices, and patient selection

Percutaneous left atrial appendage occlusion and risk of stroke, hospitalized bleeding and death in Medicare beneficiaries

PURPOSE

Among patients with atrial fibrillation (AF), a nonpharmacologic option (e.g., percutaneous left atrial appendage occlusion [LAAO]) is needed for patients with oral anticoagulant (OAC) contraindications. Among beneficiaries in the Medicare fee-for-service coverage 20% sample databases (2015-18) who had AF and an elevated CHA2DS2-VASc score, we assessed the association between percutaneous LAAO versus OAC use and risk of stroke, hospitalized bleeding, and death.

METHODS

Patients undergoing percutaneous LAAO were matched to up to five OAC users by sex, age, date of enrollment, index date, CHA2DS2-VASc score, and HAS-BLED score. Overall, 17 156 patients with AF (2905 with percutaneous LAAO) were matched (average ± SD 78 ± 6 years, 44% female). Cox proportional hazards model were used.

RESULTS

Median follow-up was 10.3 months. After multivariable adjustments, no significant difference for risk of stroke or death was noted when patients with percutaneous LAAO were compared with OAC users (HRs [95% CIs]: 1.14 [0.86-1.52], 0.98 [0.86-1.10]). There was a 2.94-fold (95% CI: 2.50-3.45) increased risk for hospitalized bleeding for percutaneous LAAO compared with OAC use. Among patients 65 to <78 years old, those undergoing percutaneous LAAO had higher risk of stroke compared with OAC users. No association was present in those ≥78 years.

CONCLUSION

In this analysis of real-world AF patients, percutaneous LAAO versus OAC use was associated with similar risk of death, nonsignificantly elevated risk of stroke, and an elevated risk of bleeding in the post-procedural period. Overall, these results support results of randomized trials that percutaneous LAAO may be an alternative to OAC use for patients with contraindications.

Considerations for Left Atrial Appendage Occlusion During Cardiac Surgery

Atrial fibrillation is associated with an increased risk of stroke secondary to thrombus formation in the left atrial appendage. Left atrial appendage occlusion (LAAO) is an effective method of reducing the risk of stroke in patients with atrial fibrillation. Although LAAO does not remove the requirement for anticoagulation, it reduces the risk of stroke when compared to anticoagulation alone. We critically analyze the data on LAAO in cardiac surgery. We also discuss the methods of LAAO, the risks of LAAO, and patient populations that could benefit from LAAO. We discuss high-level evidence that LAAO at the time of cardiac surgery reduces the risk of stroke in patients with a history of atrial fibrillation. In patients without a history of atrial fibrillation undergoing cardiac surgery, we suggest that LAAO should be considered in select patients at high risk of atrial fibrillation and stroke, when technically feasible.

Left Atrial Appendage Occlusion Versus Oral Anticoagulation in Atrial Fibrillation : A Decision Analysis

BACKGROUND

Left atrial appendage occlusion (LAAO) is a potential alternative to oral anticoagulants in selected patients with atrial fibrillation (AF). Compared with anticoagulants, LAAO decreases major bleeding risk, but there is uncertainty regarding the risk for ischemic stroke compared with anticoagulation.

OBJECTIVE

To determine the optimal strategy for stroke prevention conditional on a patient's individual risks for ischemic stroke and bleeding.

DESIGN

Decision analysis with a Markov model.

DATA SOURCES

Evidence from the published literature informed model inputs.

TARGET POPULATION

Women and men with nonvalvular AF and without prior stroke.

TIME HORIZON

Lifetime.

PERSPECTIVE

Clinical.

INTERVENTION

LAAO versus warfarin or direct oral anticoagulants (DOACs).

OUTCOME MEASURES

The primary end point was clinical benefit measured in quality-adjusted life-years.

RESULTS OF BASE-CASE ANALYSIS

The baseline risks for stroke and bleeding determined whether LAAO was preferred over anticoagulants in patients with AF. The combined risks favored LAAO for higher bleeding risk, but that benefit became less certain at higher stroke risks. For example, at a HAS-BLED score of 5, LAAO was favored in more than 80% of model simulations for CHA₂DS₂-VASc scores between 2 and 5. The probability of LAAO benefit in QALYs (>80%) at lower bleeding risks (HAS-BLED score of 0 to 1) was limited to patients with lower stroke risks (CHA₂DS₂-VASc score of 2). Because DOACs carry lower bleeding risks than warfarin, the net benefit of LAAO is less certain than that of DOACs.

RESULTS OF SENSITIVITY ANALYSIS

Results were consistent using the ORBIT bleeding score instead of the HAS-BLED score, as well as alternative sources for LAAO clinical effectiveness data.

LIMITATION

Clinical effectiveness data were drawn primarily from studies on the Watchman device.

CONCLUSION

Although LAAO could be an alternative to anticoagulants for stroke prevention in patients with AF and high bleeding risk, the overall benefit from LAAO depends on the combination of stroke and bleeding risks in individual patients. These results suggest the need for a sufficiently low stroke risk for LAAO to be beneficial. The authors believe that these results could improve shared decision making when selecting patients for LAAO.

PRIMARY FUNDING SOURCE

None.

Outcomes of cardiac surgery with left atrial appendage occlusion versus no Occlusion, direct oral Anticoagulants, and vitamin K Antagonists: A systematic review with Meta-analysis

Surgical left atrial appendage occlusion (LAAO) is being used increasingly in the setting of atrial fibrillation but has been associated with procedural complications. This systematic review and meta-analysis compared the outcomes of surgical LAAO with those of no LAAO and the use of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) using the PRISMA guidelines. A literature search was undertaken for relevant studies published between January 1, 2003, and August 15, 2021. Primary clinical outcomes were all-cause mortality, embolic events, and stroke. Secondary clinical outcomes included major adverse cardiac events (MACE), postoperative atrial fibrillation, postoperative complications, reoperation for bleeding, and major bleeding. There was a statistically significant 34% reduction in incidence of embolic events (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.57–0.77, p < 0.001) and a significant 42% reduction in risk of MACE (OR 0.58, 95% CI 0.38–0.88, p = 0.01) in patients who underwent LAAO.Surgical LAAO has the potential to reduce embolic events and MACE in patients undergoing cardiac surgery for atrial fibrillation. However, complete replacement of DOACs and warfarin therapy with surgical LAAO is unlikely despite its non-inferiority in terms of minimizing all-cause mortality, embolic events, MACE, major bleeding, and stroke in patients on oral anticoagulation therapies.

Length of stay following percutaneous left atrial appendage occlusion: Data from the prospective, multicenter Amplatzer Amulet Occluder Observational Study

Aims

To evaluate factors influencing the length of stay in patients undergoing percutaneous left atrial appendage occlusion (LAAO).

Methods and results

Patient characteristics, procedural data and the occurrence of serious adverse events were analyzed from the Amplatzer^TM Amulet^TM Occluder Observational Study. Patients were divided into three groups: same day (S, 0day, n = 60, 5.6%) early (E, 1day, n = 526, 48.9%), regular (R, 2-3days, n = 338, 31.4%) and late (L, ≥4days, n = 152, 14.1%) discharge and followed up for 60 days. Procedure and device related SAE during the in-hospital stay (S: 0.0% vs. E: 1.0% vs. R: 2.1% vs. L: 23%, p<0.0001) were a major trigger for a prolonged in-hospital stay. Of the 37 subjects in the late discharge group with an SAE prior to discharge, cardiac or bleeding complications were the most common underlying conditions, occurring in 26 subjects. Multinomial logistic analysis only identified HAS-BLED score as an independent influencing factor (p = 0.04) for a late discharge. After 60 days, mortality tended to be greatest in the late discharge group (S: 0.0% vs. E: 1.0% vs. R: 1.2% vs. L: 3.3%, p = 0.1066).

Conclusion

Over half of the subjects receiving an Amplatzer Amulet occluder were discharged within 1 day of the implant procedure. Serious adverse events were a major trigger for a late discharge after LAAO. Increased HAS-BLED score was associated with a prolonged in-hospital stay.

Safety and effects of volume loading during transesophageal echocardiography in the pre-procedural work-up for left atrial appendage closure

Background

In patients undergoing left atrial appendage (LAA) closure, an accurate sizing of the LAA is key to optimize device sizing, procedural success and reduce complications. Previous studies have shown that intraprocedural volume loading increases LAA dimensions and improves device sizing. However, the safety and effects on LAA and device sizing of administering a fluid bolus during pre-procedural transesophageal echocardiography (TEE) are unknown. The aim of this study was to determine the safety and impact on LAA dimensions and device sizing of an intravenous (IV) fluid bolus administered during TEE in the setting of the pre-procedural work-up for LAA closure.

Methods

The study included a total of 72 patients who underwent TEE to assess suitability for LAAC and received a 500 ml IV bolus of normal saline. The LAA landing zone (LZ) and depth were measured by TEE before and after volume loading, and these measurements were used to predict the device size implanted during a subsequent percutaneous LAAC procedure.

Results

There were no complications associated with volume loading. The baseline mean LZ was 19.6 ± 3.6 mm at 90^o, and 20.2 ± 4.1 mm at 135^o. Following fluid bolus, the maximum diameter increased 1.5 ± 1.0 mm at 90^o (p<0.001), and 1.3 ± 1.0 mm at 135^o (p<0.001). The baseline mean depth of the LAA was 26.5 ± 5.5 mm at 90^o, and 23.9 ± 5.8 mm at 135^o. After fluid bolus, the mean depth increased by 1.5 ± 1.8 mm (p<0.001) and 1.6 ± 2.0 (p<0.001), at 90^o and 135^o, respectively. Sizing based on post-bolus measurements of the LZ significantly improved the agreement with the final device size selection during the procedure in 71.0% of cases (vs. 42.0% with pre-bolus measurements).

Conclusions

Volume loading during ambulatory TEE as part of the pre-procedural work-up of LAAC is safe and significantly increases LAA dimensions. This strategy may become the new standard, particularly in centers performing LAAC with no TEE guidance, as it improves LAA sizing and more accurately predicts the final device size.

Comparison Between Oral Anticoagulation and Left Atrial Appendage Occlusion in the Prevention of Stroke With Regard to Non-Valvular Atrial Fibrillation

In the past, the most common type of atrial fibrillation leading to stroke was valvular; this was predominantly due to the prevalence of rheumatic fever, but with the advent of better-hospitalized care, the cases of valvular atrial fibrillation declined. In recent years, there has been an increase in cases of stroke due to non-valvular atrial fibrillation. Stasis of blood in the left atrial pouch leads to coagulation and thrombi formation, which may lead to stroke. Oral medication or mechanical intervention can prevent thrombi formation. Both oral anticoagulation and left atrial appendage occlusion (LAAO) have been compared to see which has better outcomes. It was observed that LAAO has greater efficacy, but with time throughout a couple of years, no considerable difference was seen when compared to warfarin. Most of the long-term randomized controlled trials have been performed with the Watchman^® device. Although the Lariat and Amplatzer LAAO devices have also shown favorable outcomes, there is still a deficiency when it comes to trials of high-quality evidence using these devices as an intervention. Dual therapy with both of these approaches showed a decline in the count of major bleeding episodes on follow-up. Overall, albeit both methods have proven useful, LAAO has a slight advantage in efficacy and leads to less hemorrhagic events.

The value of the left atrial appendage orifice perimeter of 3D model based on 3D TEE data in the choice of device size of LAmbre™ occluder

Preoperative optimal selection of the occluder size is crucial in percutaneous left atrial appendage (LAA) occlusion, and the maximal width of the LAA orifice is the main reference index, however it can not fully meet the practical operation requirements. We retrospectively analyzed three-dimensional (3D) transesophageal echocardiography (TEE) and computed tomography (CT) imaging dataset of the 41 patients who underwent LAA occlusion with LAmbre™ system. The LAA orifice parameters were overall evaluated to determine their role in device size selection. Eight LAA 3D models of the four cases who had been replaced their device during the procedure based on TEE and CT were printed out to verify the optimal parameter decision strategy. There was a significant concordance of the results between 3D TEE and CT in the LAA orifice evaluation. The correlations between the perimeter and maximal width measurements by 3D TEE and the closure disk of the device were stronger than that between the area measurements and the closure disk (r = 0.93, 0.95, 0.86, respectively and p < 0.001 all), and the result was similar to that by CT (r = 0.92, 0.93, 0.84, respectively and p < 0.001 all). The ratios of the maximal width to the minimal width of the four cases were all > 1.4, however the rest 37 cases were all ≤ 1.4. Based on the comprehensive assessment of the LAA orifice perimeter and maximal width of the 3D printed models, the experiments were all succeed just for one try. The LAA orifice perimeter of 3D printed model based on 3D TEE may help in choosing the optimal device size of LAmbre™, especially for the LAA with flater ostial shape.

Prevention and Treatment of Acute Stroke in the Nonagenarians and Beyond: Medical and Ethical Issues

PURPOSE OF REVIEW

As one of the fastest growing portions of the population, nonagenarians will constitute a significant percentage of the stroke patient population in the near future. Nonagenarians are nevertheless not specifically targeted by most clinical guidelines. In this review, we aimed to summarise the available evidence guiding stroke prevention and treatment in this age group.

RECENT FINDINGS

Several recent observational studies have shown that the benefits of anticoagulation for the oldest old patients with atrial fibrillation may outweigh the bleeding risk. A sub-analysis of the IST-3 trial has shown for the first time that thrombolysis treatment in acute ischaemic stroke may be beneficial and safe even in octogenarian patients and older. Several recent observational studies have assessed thrombolysis in nonagenarians. The latest of these has shown better disability outcomes without increased rates of symptomatic intracerebral haemorrhage with thrombolysis. Nonagenarian stroke patients may benefit from similar preventative and therapeutic strategies as their younger counterparts. A few important exceptions include primary prevention using aspirin or statins. Patient selection is nevertheless essential given the increased adverse event rates. Patient preference should play a key role in the decision-making process. Clinical trials including more nonagenarian patients are required to yield more robust evidence.

Left atrial appendage closure with the Ultraseal device: Initial experience and mid-term follow-up

AIMS

Left atrial appendage (LAA) closure is considered an effective option in patients with non-valvular atrial fibrillation (NVAF) and contraindications to long-term oral anticoagulant (OAC) therapy. However, there are some concerns about safety of currently available devices. Our aim is to provide an initial assessment on feasibility and safety of the novel LAA closure Ultraseal device in patients with NVAF and contraindications to long-term OAC therapy.

METHODS

Twenty-three consecutive patients with NVAF undergoing Ultraseal device implantation between July 2016 and February 2018 at two institutions were included. All patients performed transesophageal echocardiography and computed tomography angiography prior to LAA closure.

RESULTS

Procedural success was achieved in all patients except two who experienced incorrect device deployment with incomplete LAA closure. Procedure duration halved from first to last procedure performed. The only periprocedural adverse events observed were a myocardial infarction and an in-hospital death due pneumonia. At mean follow-up (166 ± 80 days) all other patients were alive and free from major bleedings and ischaemic strokes.

CONCLUSIONS

Our results suggest that the Ultraseal device is a feasible option for LAA occlusion. Notably, the learning curve in this registry was fast, paralleled by extremely low complication rates. These results should be considered hypothesis generating and larger studies are mandatory.

Association of Surgical Left Atrial Appendage Occlusion With Subsequent Stroke and Mortality Among Patients Undergoing Cardiac Surgery

IMPORTANCE

Surgical occlusion of the left atrial appendage (LAAO) may be performed during concurrent cardiac surgery. However, few data exist on the association of LAAO with long-term risk of stroke, and some evidence suggests that this procedure may be associated with subsequent development of atrial fibrillation (AF).

OBJECTIVE

To evaluate the association of surgical LAAO performed during cardiac surgery with risk of stroke, mortality, and development of subsequent AF.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study using a large US administrative database that contains data from adult patients (≥18 years) with private insurance or Medicare Advantage who underwent coronary artery bypass graft (CABG) or valve surgery between January 1, 2009, and March 30, 2017, with final follow-up on March 31, 2017. One-to-one propensity score matching was used to balance patients on 76 dimensions to compare those with vs without LAAO, stratified by history of prior AF at the time of surgery.

EXPOSURES

Surgical LAAO vs no surgical LAAO during cardiac surgery.

MAIN OUTCOMES AND MEASURES

The primary outcomes were stroke (ie, ischemic stroke or systemic embolism) and all-cause mortality. The secondary outcomes were postoperative AF (AF within 30 days after surgery among patients without prior AF) and long-term AF-related health utilization (event rates of outpatient visits and hospitalizations).

RESULTS

Among 75 782 patients who underwent cardiac surgery (mean age, 66.0 [SD, 11.2] years; 2 2091 [29.2%] women, 25 721 [33.9%] with preexisting AF), 4374 (5.8%) underwent concurrent LAAO, and mean follow-up was 2.1 (SD, 1.9) years. In the 8590 propensity score-matched patients, LAAO was associated with a reduced risk of stroke (1.14 vs 1.59 events per 100 person-years; hazard ratio [HR], 0.73 [95% CI, 0.56-0.96]; P = .03) and mortality (3.01 vs 4.30 events per 100 person-years; HR, 0.71 [95% CI, 0.60-0.84]; P < .001). LAAO was associated with higher rates of AF-related outpatient visits (11.96 vs 10.26 events per person-year; absolute difference, 1.70 [95% CI, 1.60-1.80] events per person-year; rate ratio, 1.17 [95% CI, 1.10-1.24]; P < .001) and hospitalizations (0.36 vs 0.32 event per person-year; absolute difference, 0.04 [95% CI, 0.02-0.06] event per person-year; rate ratio, 1.13 [95% CI, 1.05-1.21]; P = .002). In patients with prior AF (6438/8590 [74.9%]) with vs without LAAO, risk of stroke was 1.11 vs 1.71 events per 100 person-years (HR, 0.68 [95% CI, 0.50-0.92]; P = .01) and risk of mortality was 3.22 vs 4.93 events per 100 person-years (HR, 0.67 [95% CI, 0.56-0.80]; P < .001), respectively. In patients without prior AF (2152/8590 [25.1%]) with vs without LAAO, risk of stroke was 1.23 vs 1.26 events per 100 person-years (HR, 0.95 [95% CI, 0.54-1.68]), risk of mortality was 2.30 vs 2.49 events per 100 person-years (HR, 0.92 [95% CI, 0.61-1.37]), and risk of postoperative AF was 27.7% vs 20.2% events per 100 person-years (HR, 1.46 [95% CI, 1.22-1.73]; P < .001). The interaction term between prior AF and LAAO was not significant (P = .29 for stroke and P = .16 for mortality).

CONCLUSIONS AND RELEVANCE

Among patients undergoing cardiac surgery, concurrent surgical LAAO, compared with no surgical LAAO, was associated with reduced risk of subsequent stroke and all-cause mortality. Further research, including from randomized clinical trials, is needed to more definitively determine the role of surgical LAAO.

Complex Structural Interventions: The Role of Computed Tomography, Fluoroscopy, and Fusion Imaging

Noninvasive cardiac imaging has played a critical part in the evaluation, monitoring, and follow-up of structural heart disease. This review will highlight the role of cardiac computed tomography, fluoroscopy, and fusion imaging in guiding transcatheter aortic valve replacement and other percutaneous strategies used to diagnose and treat complex structural heart complications.

Percutaneous Left Atrial Appendage Closure: is there a Role in Valvular Atrial Fibrillation

Atrial fibrillation, a chronic and highly morbid cardiovascular condition which affects over 33 million people worldwide, can be broadly categorized as valvular vs non-valvular in etiology. However, definitions of valvular atrial fibrillation have varied widely in the literature, and there is no clear consensus definition to date. Historically, patients with atrial fibrillation in the setting of rheumatic mitral valve disease have constituted a particularly high risk group for cardioembolic stroke, and for this reason many contemporary trials of pharmaceutical and device therapies for atrial fibrillation have systematically excluded patients with valvular heart disease. Therefore, vitamin K antagonism remains the favored approach to mitigate stroke risk in valvular atrial fibrillation, and the optimal strategy to treat atrial fibrillation patients with valvular heart disease who cannot tolerate oral anticoagulation therapy is unknown. Recent trials have demonstrated an important role for percutaneous left atrial appendage occlusion devices in patients with non-valvular atrial fibrillation, but the role of these devices in patients with valvular atrial fibrillation is uncertain. Given the worldwide burden of valvular atrial fibrillation, future trials intended to clarify the role of percutaneous left atrial appendage closure devices in valvular atrial fibrillation should provide important insight for the care of millions of patients.

Who Should Be Referred for Left Atrial Appendage Occlusion Therapy?

OPINION STATEMENT

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting approximately 7 million individuals in USA. It is one of the most significant arrhythmias, which accounts for a majority of embolic strokes, especially in elderly individuals. Although oral anti-coagulation is beneficial in lowering the risk of stroke, 1 in 10 patients have a contra-indication to warfarin therapy. Among patients who do tolerate either warfarin or novel oral anticoagulant (NOAC), major or recurrent bleeding, intracranial bleeds, etc. often lead to interruption of anti-coagulation. Previous studies have reported that >90% of cardioemboli in non-valvular atrial fibrillation (NVAF) originate in the left atrial appendage. Left atrial appendage occlusion (LAAO) is currently covered by the Centers for Medicare & Medicaid Services (CMS) as an alternative for stroke prevention in patients with an elevated stroke risk (CHADS2 ≥2 or CHA2DS2-VASc score ≥3) who have appropriate rational for avoiding long-term oral anticoagulation following a shared-decision making process. In this review, we discuss the currently available LAAO devices and more importantly, appropriate patient selection for this strategy.

Recent Advances in Stroke Prevention in Patients with Atrial Fibrillation and End-Stage Renal Disease

BACKGROUND

Chronic kidney disease (CKD) is associated with a high prevalence of atrial fibrillation (AF), but in this population the risk/benefit ratio of anticoagulant therapy with vitamin K antagonists (VKA) for thromboprophylaxis is uncertain.

SUMMARY

In end-stage renal disease (ESRD) patients undergoing hemodialysis, VKA seem less effective in stroke prevention than in the general population, with an increased risk of major bleeding. Recently, novel oral anticoagulant agents (NOACs) have proven to be effective for stroke prevention in AF and have demonstrated an improved safety profile compared to VKA. Limited data from post hoc analyses of controlled clinical trials suggest the safe and effective use of NOACs in patients with moderate renal impairment (i.e., estimated glomerular filtration rate, eGFR, between 30 and 50 mL/min). The question still remains whether NOACs can be used in patients with an eGFR <30 mL/min, since there are no studies addressing this subject. In fact, patients with CKD stage 4 and 5 were excluded from controlled clinical trials on anticoagulation therapy for stroke prevention in AF. Left atrial appendage (LAA) occlusion represents a nonpharmacological alternative for stroke prevention in patients with AF who are difficult to manage medically. Preliminary data indicate a similar efficacy and safety profile in patients with CKD compared to patients with normal renal function.

KEY MESSAGES

Stroke prevention in patients with ESRD and AF represents a clinical challenge with poor evidence. LAA occlusion may become the standard of care for stroke prevention in patients with ESRD and AF.

Rivaroxaban as an effective alternative to warfarin in a patient with atrial fibrillation, thrombophilia, and left atrial appendage thrombus: a case report

Background

Atrial fibrillation is the most common cardiac arrhythmia. It is responsible for up to 20% of all ischemic strokes. Rate control and anticoagulation are crucial for atrial fibrillation management and stroke prevention.

Case presentation

We present the case of an 84-year-old Italian woman with a left atrial appendage thrombus that developed despite her use of anticoagulant therapy with warfarin for a previous pulmonary embolism. She had atrial fibrillation and heterozygosity for both factor V Leiden and methylenetetrahydrofolate reductase C677T mutation, thus creating resistance to activated protein C. Anticoagulant therapy was switched to heparin for 1 week and then to rivaroxaban. After 3 months of rivaroxaban use, the thrombus disappeared.

Conclusions

This case raises the issue of the ineffectiveness of warfarin therapy in complex cases involving particular thrombophilic conditions and the possibility of using rivaroxaban as a safe and effective alternative.