Temporal changes and clinical significance of peridevice leak following left atrial appendage occlusion with Amplatzer devices

Reproducibility of cardiac computed tomography classifications of hypoattenuated thickening and peridevice leak following left atrial appendage closure

AIMS

To assess the reproducibility of interpreting hypoattenuated thickening (HAT) and peridevice leak (PDL) using cardiac computed tomography (CT) imaging following Watchman FLX left atrial appendage closure (LAAC).

METHODS AND RESULTS

In this multicentre retrospective reproducibility study, 100 anonymized post-LAAC cardiac CT scans were evaluated within the same cardiac phase by an experienced and a novice rater blinded to prior evaluations. All scans were evaluated twice by each rater, assessing overall HAT and PDL categories as well as specific associated findings based on suggested algorithms for post-LAAC interpretation. Inter- and intra-rater agreement and reliability were evaluated using absolute agreement, Cohen's kappa, and Kendall's tau for categorical variables, and mean difference, Bland-Altman plots, limits of agreement (lower and upper), and intra-class correlation coefficients (ICCs) for continuous variables. Within overall categories of both HAT and PDL, substantial agreement (kappa ≥0.61) and reliability (Kendall's tau-b ≥ 0.75) were observed. Specifically, identifying high-grade HAT (kappa ≥0.78) and distal patency (kappa ≥0.85) displayed the highest agreement within HAT and PDL interpretation. Meanwhile, measuring the height of the proximal screw hub cove represented the least reliable HAT assessment among both inter- and intra-rater comparisons (ICC < 0.75), while suspected leak mechanism represented the least reproducible PDL measure.

CONCLUSION

Despite only minimal training of one rater, overall high levels of inter- and intra-rater agreement and reliability were observed across the chosen algorithms for interpretation of HAT and PDL following Watchman FLX LAAC. The prognostic implications of the included variables are to be explored in future trials and registries.

Peri-device leakage and delayed endothelialization of the Watchman device: a computed tomography study

OBJECTIVES

This study aimed to explore the endothelialization process and assess the potential association between endothelialization and peri-device leak (PDL) following Watchman implantation via a quantitative method.

METHODS

This is a single-center retrospective study of consecutive patients undergoing LAAO between December 2015 and November 2021. Device endothelialization, compared between PDL and non-PDL group, were quantitatively analyzed based on hypoattenuated thickening in cardiac computed tomography angiography (CCTA). Advancement in endothelialization over time were explored using the Cochran-Armitage test and generalized estimating equation approach. Potential risk factors of delayed endothelialization were analyzed using the Cox proportional-hazards model.

RESULTS

A total of 172 patients (mean age, 68 years ± 10 [standard deviation], 114 men) were finally included. The average endothelialization ratio of the study population was 89.8 ± 7.2 percent. In the follow-up period of postprocedural 3 months to more than 12 months, an incremental trend of endothelialization over time was observed with the ratio of 85.8 ± 8.0, 89.6 ± 7.6, 92.2 ± 4.5, 94.3 ± 2.9 percent, respectively (p < 0.0001). Notably, patients without PDL exhibited a swifter advancement in endothelialization compared to those with PDL, irrespective of device size. The multivariable Cox regression model showed that PDL (HR = 2.113, 95%CI: 1.300-3.435, p = 0.003), DSP (HR = 1.717, 95%CI: 1.113-2.647, p = 0.014) were independent risk factors of delayed endothelialization.

CONCLUSION

CCTA holds promise as an effective means of quantitatively assessing device endothelialization. Endothelialization advanced gradually over time, with PDL potentially impeding device endothelialization.

CLINICAL RELEVANCE STATEMENT

A comprehensive understanding of the correlation between endothelialization ratio, time, and residual shunt can establish a more dependable foundation for determining the appropriate anticoagulation treatment following left atrial appendage closure.

KEY POINTS

Current recommendations for postleft atrial appendage occlusion anti-platelet and anticoagulation therapy are based on animal studies. Cardiac computed tomography angiography (CCTA) combined with the UNet neural network model enables the quantitative assessment of device endothelialization. This technique will allow for additional studies to better understand device endothelialization to optimize treatments in this population.

Position Statement on Cardiac Computed Tomography Following Left Atrial Appendage Occlusion

Left atrial appendage occlusion (LAAO) is rapidly growing as valid stroke prevention therapy in atrial fibrillation. Cardiac imaging plays an instrumental role in preprocedural planning, procedural execution, and postprocedural follow-up. Recently, cardiac computed tomography (CCT) has made significant advancements, resulting in increasing use both preprocedurally and in outpatient follow-up. It provides a noninvasive, high-resolution alternative to the current standard, transesophageal echocardiography, and may display advantages in both the detection and characterization of device-specific complications, such as peridevice leak and device-related thrombosis. The implementation of CCT in the follow-up after LAAO has identified new findings such as hypoattenuated thickening on the atrial device surface and left atrial appendage contrast patency, which are not readily assessable on transesophageal echocardiography. Currently, there is a lack of standardization for acquisition and interpretation of images and consensus on definitions of essential findings on CCT in the postprocedural phase. This paper intends to provide a practical and standardized approach to both acquisition and interpretation of CCT after LAAO based on a comprehensive review of the literature and expert consensus among European and North American interventional and imaging specialists.

Long-term cardiac computed tomography follow-up after left atrial appendage occlusion

BACKGROUND

Left atrial appendage occlusion (LAAO) is performed increasingly, but long-term follow-up imaging data are lacking.

AIMS

The aim of this study was to evaluate the safety and durability of the Amplatzer Amulet device >4 years after LAAO.

METHODS

This was a prospective observational cohort study including 52 patients implanted with the Amplatzer Amulet device at Aarhus University Hospital, Denmark. A >4-year follow-up cardiac computed tomography (CT) scan after LAAO was performed and compared with the results from the 2-month and 12-month scans. The primary outcome was left atrial appendage (LAA) sealing based on distal LAA contrast patency and peridevice leakage (PDL), stratified into complete occlusion (grade 0 [G0]) and grade 1-3 leakage (G1-3), respectively. Secondary outcomes were low- and high-grade hypoattenuated thickening (HAT), device-related thrombosis (DRT) and device durability.

RESULTS

The median (interquartile range [IQR]) follow-up time from LAAO to the latest CT scan was 5.8 years (4.5; 6.3). At 2-month (n=52), 12-month (n=27) and >4-year CT follow-ups (n=52), rates of both complete occlusion (33%, 37%, 35%) and G2 leaks (52%, 52%, 48%) remained stable. Rates of G1 leaks varied (14%, 4%, 6%) and G3 leaks rose (2%, 7%, 12%) from earliest to latest follow-up. The median left atrial (LA) volume increased from 127 mL (96; 176) to 144 mL (108; 182) and 147 mL (107; 193). No DRT was found. The structural device integrity was preserved.

CONCLUSIONS

This study indicates a stable LAA sealing status throughout the follow-up period, emphasising the importance of the procedural result in avoiding PDL. Few patients displayed PDL progression, which might partly be related to LA remodelling with increasing volume. The long-term device durability appears excellent. Larger studies are warranted to confirm these findings.

Lights and shadows on left atrial appendage occlusion: mind the gap in knowledge and think twice on long-term outcomes

Ischemic stroke prevention represents a crucial concern in health systems, being associated with high morbidity and mortality. Atrial fibrillation is associated with 15-20% of ischemic strokes, in the presence of thrombus in the left atrial appendage in 90% of patients with nonvalvular atrial fibrillation. Oral anticoagulation represents the standard of care. However, left atrial appendage occlusions have been developed for selected patients with nonvalvular atrial fibrillation. With regard to the latter, particularly, some important concerns have been raised on the selection of patients potentially amenable to the procedure, seemingly emphasizing a gap in knowledge, real-life clinical practice, and current management guidelines. In light of the recent evidence regarding the current indications for management of left atrial appendage in presence of nonvalvular atrial fibrillation, the purpose of this critical review is to highlight the blind spots of left atrial appendage occlusion indications, taking into account the evidence-based mid- to long-term outcomes. Apparently, many unsolved concerns and problems are still present, mainly including mid- and long-term device-related potential complications, the possibility of concurrent sources of embolization, ethical and economic issues. Furthermore, larger, well designed, long-term, multicentric, and more inclusive studies, as well as shared/integrated registries are needed, aiming at comparing direct oral anticoagulation with left atrial appendage occlusion in the long run.

Incidence, impact and predictors of residual device patency after left atrial appendage closure with the LACbes device

BACKGROUND

The residual device patency (RDP) after left atrial appendage closure (LAAC) with the LACbes device has not been specifically explored in atrial fibrillation (AF) patients. This study aims to explore the incidence, impact and predictors of RDP detected by cardiac computed tomography angiography (CCTA) post LAAC.

METHODS

AF patients implanted with the LACbes device were prospectively enrolled. CCTA device surveillance was performed at 3 months post-procedure. Major adverse events (MAEs), including stroke/transient ischemic attack, major bleeding and all-cause death, were evaluated.

RESULTS

Among 141 patients with CCTA surveillance, 56 (39.7%) showed no visible leak and 85 (60.3%) showed RDP. During the median follow-up of 443 [232, 706] days, the presence of RDP was not associated with an increased risk of MAEs (adjusted hazard ratio [HR]: 4.07, 95% confidence interval [CI]: 0.49-34.24, p = 0.196), while peri-device leak (PDL) at the lobe was associated with heightened risks of MAEs (adjusted HR: 6.85, 95% CI: 1.62-28.89, p = 0.009). In patients with PDL at the lobe, antiplatelet after 6 months (HR: 0.20, 95% CI: 0.05-0.91, p = 0.038) was independent protective predictor of MAEs. Besides, current smoking (odds ratio [OR]: 7.52, 95% CI: 2.68-21.08, p < 0.001) and maximum diameter of LAA orifice (OR: 1.16, 95% CI: 1.00-1.34, p = 0.048) were independent predictors of PDL at the lobe.

CONCLUSIONS

Presence of PDL at the device lobe detected by CCTA at 3-month post LAAC with LACbes is associated with unfavorable prognosis in AF patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03788941.

Residual leaks following percutaneous left atrial appendage occlusion and outcomes: a meta-analysis

BACKGROUND AND AIMS

Residual leaks are not infrequent after left atrial appendage occlusion. However, there is still uncertainty regarding their prognostic implications. The aim of this study is to evaluate the impact of residual leaks after left atrial appendage occlusion.

METHODS

A literature search was conducted until 19 February 2023. Residual leaks comprised peri-device leaks (PDLs) on transoesophageal echocardiography (TEE) or computed tomography (CT), as well as left atrial appendage patency on CT. Random-effects meta-analyses were performed to assess the clinical impact of residual leaks.

RESULTS

Overall 48 eligible studies (44 non-randomized/observational and 4 randomized studies) including 61 666 patients with atrial fibrillation who underwent left atrial appendage occlusion were analysed. Peri-device leak by TEE was present in 26.1% of patients. Computed tomography-based left atrial appendage patency and PDL were present in 54.9% and 57.3% of patients, respectively. Transoesophageal echocardiography-based PDL (i.e. any reported PDL regardless of its size) was significantly associated with a higher risk of thromboembolism [pooled odds ratio (pOR) 2.04, 95% confidence interval (CI): 1.52-2.74], all-cause mortality (pOR 1.16, 95% CI: 1.08-1.24), and major bleeding (pOR 1.12, 95% CI: 1.03-1.22), compared with no reported PDL. A positive graded association between PDL size and risk of thromboembolism was noted across TEE cut-offs. For any PDL of >0, >1, >3, and >5 mm, the pORs for thromboembolism were 1.82 (95% CI: 1.35-2.47), 2.13 (95% CI: 1.04-4.35), 4.14 (95% CI: 2.07-8.27), and 4.44 (95% CI: 2.09-9.43), respectively, compared with either no PDL or PDL smaller than each cut-off. Neither left atrial appendage patency, nor PDL by CT was associated with thromboembolism (pOR 1.45 and 1.04, 95% CI: 0.84-2.50 and 0.52-2.07, respectively).

CONCLUSIONS

Peri-device leak detected by TEE was associated with adverse events, primarily thromboembolism. Residual leaks detected by CT were more frequent but lacked prognostic significance.

Midterm follow-up after computed tomography angiography planned left atrial appendage closure

BACKGROUND

While studies have shown the advantages of computed tomography angiography (CTA) over transesophageal echocardiography (TEE) in left atrial appendage closure (LAAC) preprocedural planning for WATCHMAN™ legacy and FLX devices, there has been no reported long-term data for this approach.

OBJECTIVES

We sought to evaluate long-term outcomes using CTA-based preprocedural planning for LAAC using the WATCHMAN™ device.

METHODS

A prospective analysis of 231 consecutive patients who underwent LAAC in a single, large academic hospital in the United States was conducted over a 5-year period. CTA-guided preprocedural planning was performed in all. Procedural success, adverse events, length of procedure, number of devices used, and length of stay were evaluated. Rates of death, cerebral embolism, systemic embolism, and major and minor bleeding were recorded. Adjusted predicted stroke and major bleeding rates were derived from CHA2DS2-Vasc and HAS-BLED scores, respectively.

RESULTS

From January 26, 2017, to November 23, 2021, 231 patients underwent LAAC with CTA preprocedural planning by two operating physicians. The mean age of patients was 76.5 ± 8.4. 59.7% of patients were male. Mean CHA2DS2VASc and HAS-BLED scores were 4.5 ± 1.4 and 3.9 ± 0.9, respectively. All procedures were performed with intracardiac echo (100%). The procedural success rate was 99.1%. The CTA sizing strategy accurately predicted the implant size in 93.5% of patients. Mean number of devices used was 1.10 ± 0.3. Peri-procedural complication rate was 2.2%. 6 patients were lost to follow-up. Mean follow-up was 608.94 days with a total of 377.04 patient years. Median follow-up period of 368 days (interquartile range: 209-1067 days). There were 51 deaths from all causes (13.52 per 100 patient-years), 10 cases of cerebral embolism (2.65 per 100 patient-years), 2 cases of systemic embolism (0.53 per 100 patient-years), 17 cases of major bleeding (4.50 per 100 patient-years), and 31 cases of minor bleeding (8.2 per 100 patient-years). All-cause mortality at 1, 2, and 3 years was 12.7%, 20.9%, and 29.2%, respectively. CV event rates at 1, 2, and 3 years were 2.1%, 6.6%, and 10.5%, respectively.

CONCLUSIONS

CTA-based preprocedural planning is accurate in predicting device size for LAAC and associated with excellent clinical outcomes at 5 years.

Meta-Analysis of the Outcomes of Peri-Device Leak After Left Atrial Appendage Closure

Left atrial appendage closure (LAAC) reduces the risk of thromboembolic stroke in atrial fibrillation. Peri-device leak (PDL) after LAAC may affect the subsequent risk of thromboembolism. We conducted a systematic review and meta-analysis to evaluate the effect of PDL after LAAC. We searched PubMed/Medline, Embase, and Google Scholar for studies reporting outcomes of PDL after LAAC from inception through October 2022. The primary outcome was the composite of stroke, transient ischemic attack (TIA), or systemic embolism (SE). Secondary outcomes included all-cause and cardiovascular mortality, ischemic stroke, TIA, and device-related thrombus. Outcomes were pooled using random-effects models. We used I2 statistics to assess statistical heterogeneity; I2 >50% considered significant heterogeneity. This study included 54,279 patients from 11 studies (6 observational, 2 nonrandomized controlled trials [non-RCTs] primary results, 2 RCT post hoc analyses, and 1 analysis combining 2 RCTs data). PDL was associated with a significant increase in the composite outcome of stroke, TIA, or SE (odds ratio 1.63, 95% confidence interval 1.06 to 2.52, p = 0.03, I2 = 43%) as compared with cases with no PDL. There were no significant differences in all-cause or cardiovascular mortality, ischemic stroke, TIA, or device-related thrombus. In conclusion, PDL after LAAC is associated with an increased risk of thromboembolism (composite stroke, TIA, or SE) without impacting mortality.

Progress in the study and treatment of peri-device leak after left atrial appendage closure

For patients with atrial fibrillation with an increased risk of stroke and contraindications to long-term anticoagulation, percutaneous left atrial appendage closure (LAAC) has become an important alternative to long-term oral anticoagulation. Incomplete closure of the LAAC during the procedure leads to faster blood flow in the interstitial space around the device, resulting in peri-device leak (PDL), which is not uncommon. Studies are still inconclusive in determining the incidence, long-term safety, and management of PDL. Therefore, this article reviewed the progress made in the research and treatment of PDL after LAAC.

Peridevice Leak After Left Atrial Appendage Occlusion: Incidence, Mechanisms, Clinical Impact, and Management

Left atrial appendage occlusion is an increasingly adopted stroke prevention strategy in patients with atrial fibrillation. However, peridevice leaks after the procedure are not infrequent and have recently been shown to confer a higher risk for subsequent ischemic events. In this paper, the authors review the available research on the frequency, mechanisms, clinical significance, and management of peridevice leak after percutaneous left atrial appendage occlusion.

Left atrial appendage sealing performance of the Amplatzer Amulet and Watchman FLX device

BACKGROUND

The left atrial appendage (LAA) sealing properties of the Amplatzer Amulet and Watchman FLX devices were compared using cardiac computed tomography (CT) follow-up.

METHODS

Single-center cohort study of patients undergoing LAAO between 2017 and 2020. Two consecutive cohorts were enrolled, one treated with the Amplatzer Amulet (n = 150) up till 2019, and a second cohort treated with the Watchman FLX (n = 150) device from 2019. Cardiac CT was performed 2 months postprocedure. The primary outcome was complete LAA occlusion defined as no visible peri-device leak (PDL) and absence of contrast patency in the distal LAA. Secondary outcomes included PDL, contrast patency without visible PDL, PDL area, and periprocedural complications.

RESULTS

Complete occlusion was achieved in 39 (30.5%) of the Amulet group, compared to 89 (71.8%) of the FLX group, p < 0.001. A PDL at the Amulet disc was present in 65 (50.8%), at the lobe in 16 (12.5%), and at both the disc and lobe in 13 (10.2%). For FLX, a PDL was present in 20 (16.1%). Contrast patency without visible PDL was observed in 24 (18.8%) and 15 (12.1%) of the Amulet and FLX group, respectively. The PDL area at the Amulet mid-lobe was 92 mm² (59-158) and 32 mm² (IQR 28-96) for FLX, p = 0.019. Device-related thrombosis occurred in 1 (0.7%) and 2 (1.3%), respectively (p = 0.99), with periprocedural adverse events occurring in 6 (4%) and 8 (5.3%) of the Amulet and FLX group (p = 0.79).

CONCLUSION

Complete LAA occlusion was achieved in a significantly higher proportion treated with the Watchman FLX compared to the Amulet device. PDL was smaller with the FLX than the Amulet. Conceptual device design differences make interpretation of results complex, and additional studies with clinical outcomes are needed.

Left atrial appendage occlusion

Prevention of stroke represents a goal of primary importance in health systems due to its associated morbidity and mortality. As several patient groups with increased stroke rates have been identified, multiple approaches have been developed and implemented: oral anticoagulation (OAC) for patients with atrial fibrillation, surgical and percutaneous revascularisation in patients with carotid disease, device closure for patients with patent foramen ovale, and now, left atrial appendage occlusion (LAAO) for selected patients with non-valvular atrial fibrillation (NVAF). The latter group of patients are the focus of this review which evaluates the pathophysiology, selection of patients, procedural performance, outcomes of treatment both during and post-procedure, adjunctive therapy, complications, and longer-term outcomes.

Left Atrial Appendage Occlusion: Current Advances and Remaining Challenges

The field of left atrial appendage occlusion is rapidly evolving. However, several issues remain including the limited randomized efficacy data, peri-device leak, device-related thrombus, and the ongoing refinement of procedural techniques. In this article, we provide a contemporary overview of left atrial appendage occlusion focusing on 4 key remaining challenges: efficacy data, peri-device leak, device-related thrombus, and procedural optimization.