Impact of gender in patients with device-related thrombosis after left atrial appendage closure - A sub-analysis from the multicenter EUROC-DRT-registry.

BACKGROUND: Device-related thrombosis (DRT) is a common finding after left atrial appendage closure (LAAC) and is associated with worse outcomes. As women are underrepresented in clinical studies, further understanding of sex differences in DRT patients is warranted. METHODS AND RESULTS: This sub-analysis from the EUROC-DRT-registry compromises 176 patients with diagnosis of DRT after LAAC. Women, who accounted for 34.7% (61/176) of patients, were older (78.0 ± 6.7 vs. 74.9 ± 9.1 years, p = .06) with lower rates of comorbidities. While DRT was detected significantly later in women (173 ± 267 vs. 127 ± 192 days, p = .01), anticoagulation therapy was escalated similarly, mainly with initiation of novel oral anticoagulant (NOAC), vitamin K antagonist (VKA) or heparin. DRT resolution was achieved in 67.5% (27/40) of women and in 75.0% (54/72) of men (p = .40). In the remaining cases, an intensification/switch of anticoagulation was conducted in 50.% (9/18) of men and in 41.7% (5/12) of women. Final resolution was achieved in 72.5% (29/40) cases in women, and in 81.9% (59/72) cases in men (p = .24). Women were followed-up for a similar time as men (779 ± 520 vs. 908 ± 687 days, p = .51). Kaplan-Meier analysis revealed no difference in mortality rates in women (Hazard Ratio [HR]: 1.73, 95%-Confidence interval [95%-CI]: .68-4.37, p = .25) and no differences in stroke (HR: .83, 95%-CI: .30-2.32, p = .72) within 2 years after LAAC. CONCLUSION: Evaluation of risk factors and outcome revealed no differences between men and women, with DRT in women being diagnosed significantly later. Women should be monitored closely to assess for DRT formation/resolution. Treatment strategies appear to be equally effective.

The CT derived angle between the transseptal puncture site and the left atrial appendage as a predictor for complex interventional occlusion procedures.

OBJECTIVE: To evaluate the role of the CT-derived angle between the intra-atrial septum (IAS) and the left atrial appendage (LAA) on procedural complexity and clinical outcomes in left atrial appendage occlusion (LAAO) procedures. BACKGROUND: Given the broad variations in anatomy, LAAO remains one of the most challenging interventional procedures in structural heart disease. In recent years, preprocedural cardiac tomography (CT) has evolved as a valuable tool; however, prediction of procedural complexity remains cumbersome. METHODS: We retrospectively analyzed 47 patients that underwent LAAO at our center in whom pre-procedural cardiac CT-scans were available. Among other baseline parameters, we measured the angle between the LAA ostium and the preferred transseptal puncture site at the IAS. We compared patients with an angle above and below the median regarding procedural characteristics and procedural outcome. RESULTS: The median angle between the LAA and the IAS was 127.3° (IQR: 120.9-141.3). LAAO took longer in patients with a measured angle below the median (55.0 ± 22.7 min vs. 41.3 ± 17.5 min; p = .04), resulting in longer radiation times (13.0 ± 5.3 min vs. 9.8 ± 5.7 min; p = .04) and more contrast use (61.1 ± 47.5 mL vs. 33.6 ± 24.7 mL; p = .05). Moreover, the necessity for a sheath exchange was significantly higher (30.4% vs. 4.2%, p = .02) and device repositioning or device resizing trended to be more frequent (26.1% vs. 8.3%; p = .1 and 21.7% vs. 8.3%; p = .2). There were no differences in procedural outcome, device-position and peri-device leak (PDL). CONCLUSIONS: The angle between the transseptal puncture site and the LAA ostium may serve as a predictor for more demanding LAAO interventions. In our study a steeper angle led to a prolonged procedure resulting in higher doses of contrast and radiation, but was not associated with a worse procedural outcome.

Incidence, persistence, and clinical relevance of iatrogenic atrial septal defects after percutaneous left atrial appendage occlusion.

OBJECTIVE: To investigate the rate and clinical impact of a persisting iatrogenic atrial septal defect (iASD) after percutaneous left atrial appendage occlusion (LAAO). BACKGROUND: Percutaneous LAAO is an alternative to oral anticoagulation (OAC) for the prevention of ischemic stroke and systemic embolism in patients with atrial fibrillation (AF). Data regarding incidence and persistence of iASD after LAAO procedures and its clinical relevance is scarce. METHODS: We retrospectively analyzed 144 patients that underwent LAAO at our center between 2009 and 2020 who had at least one follow-up including transesophageal echocardiography (TEE). Baseline clinical, procedural data and echocardiographic characteristics in patients with and without evidence of an iASD were compared. We furthermore determined the rate of iASD persistence over time and evaluated outcomes of patients with and without spontaneous iASD closure. RESULTS: After a median of 92 days (IQR 75-108 days) after LAAO, 50 patients (50/144, 34.7%) showed evidence of an iASD. Patients with iASD had higher CHADS-VASc-scores (4.9±1.5 vs 4.2±1.2, p = 0.03), larger left atrial volumes (80.5±30.5 ml vs 67.1±19.7 ml, p = 0.01) and were more likely to have relevant mitral regurgitation (≥° II) (46.0% vs 12.3%, p = 0.001). LAAO procedures took longer (50.1±24.3 vs 41.1±17.8 min, p = 0.06) in patients with a persisting iASD. Furthermore, larger device sizes were implanted (24.3±3.4 mm vs 22.1±2.8 mm, p = 0.03). The presence of an iASD had no impact on RV dysfunction, thromboembolism or mortality. Spontaneous closure of an iASD was documented in 52.0% (26/50). Hereby, similar risk factors were identified for the persistence of an iASD in follow-up.

Characteristics and outcomes of patients undergoing transcatheter mitral valve replacement with the Tendyne system.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) has emerged as alternative to transcatheter edge-to-edge repair (TEER) for treatment of mitral regurgitation (MR); however, the role of TMVR with the Tendyne system among established treatments of MR is not well defined. We assessed characteristics and outcomes of patients treated with the Tendyne system in the current clinical practice. METHODS: We reviewed patients who underwent cardiac computed tomography and were judged eligible for the Tendyne system. RESULTS: A total of 63 patients were eligible for TMVR with the Tendyne system. Of these, 17 patients underwent TMVR, and 46 were treated by TEER. Patients treated with the Tendyne system were more likely to have a high transmitral pressure gradient and unsuitable mitral valve morphology for TEER than those treated with TEER. TMVR with the Tendyne system reduced the severity of MR to less than 1 + in 94.1% of the patients at discharge and achieved a greater reduction in left ventricular (LV) end-diastolic volume at the 30-day follow-up compared with TEER. In contrast, patients treated with the Tendyne system had a higher 30-day mortality than those treated with TEER, while the mortality between 30 days and one year was comparable between Tendyne and TEER. CONCLUSIONS: Among patients eligible for the Tendyne system, approximately a quarter of the patients underwent TMVR with the Tendyne system, which led substantial reduction of MR and LV reverse remodeling than TEER. In contrast, the 30-day mortality rate was higher after TMVR with the Tendyne compared to TEER.

Contrast-free left atrial appendage occlusion in patients using the LAMBRE™ device.

BACKGROUND: Advances in imaging have led to procedural optimization of left atrial appendage closure (LAAC). Contrast-free approaches, guided merely by echocardiography, have been established, however data on this topic remains scarce. In this analysis, we assessed contrast-free procedural results with the LAMBRE LAAC device. METHODS: The multicenter retrospective BoBoMa (Bonn/Bordeaux/Mainz)-Registry included a total of 118 patients that underwent LAAC with LAMBRE devices omitting contrast-dye. Baseline and echocardiographic characteristics as well as intra- and postprocedural complications and outcomes were assessed. RESULTS: Patients were at a mean age of 77.5 ± 7.5 years with high thromboembolic and bleeding risk (CHADS-VASc-score 4.6 ± 1.4, HAS-BLED-score 3.7 ± 1.0, respectively). Renal function was impaired with a mean glomerular filtration rate (GFR) of 50 ± 22 ml/min. Mean procedural time was 47.2 ± 37.5  minutes with a mean radiation dose of 4.75 ± 5.25 Gy*cm2. Device success, defined as proper deployment in a correct position, was achieved in 97.5% (115/118) of cases with repositioning of the occluder in 7.6% (9/118) and resizing in 3.4% (4/118) of cases. No relevant peri-device leakage (>3 mm) was observed with 42% of occluders being implanted in an ostial position. Periprocedural complications occurred in 6.8% (8/118) of cases, including two cases of device embolization and one case of clinically-relevant pericardial effusion requiring surgical intervention. Other complications included pericardial effusion (2.5%, 3/118) and vascular access site complications (1.7%, 2/118). CONCLUSION: Echocardiography-guided contrast-free LAAC using the LAMBRE device is safe and feasible. Further prospective studies including the direct comparison of devices as well as imaging techniques are warranted in contrast-free LAAC.

Contemporary Treatment and Outcomes of High Surgical Risk Mitral Regurgitation.

Before the development of transcatheter interventions, patients with mitral regurgitation (MR) and high surgical risk were often conservatively treated and subject to poor prognoses. We aimed to assess the therapeutic approaches and outcomes in the contemporary era. The study participants were consecutive high-risk MR patients from April 2019 to October 2021. Among the 305 patients analyzed, 274 (89.8%) underwent mitral valve interventions, whereas 31 (10.2%) received medical therapy alone. Of the interventions, transcatheter edge-to-edge mitral repair (TEER) was the most frequent (82.0% of overall), followed by transcatheter mitral valve replacement (TMVR) (4.6%). In patients treated with medical therapy alone, non-optimal morphologies for TEER and TMVR were shown in 87.1% and 65.0%, respectively. Patients undergoing mitral valve interventions experienced less frequent heart failure (HF) rehospitalization compared to those with medical therapy alone (18.2% vs. 42.0%, p < 0.01). Mitral valve intervention was associated with a lower risk of HF rehospitalization (HR 0.36 [0.18-0.74]) and an improved New York Heart Association class (p < 0.01). Most high-risk MR patients can be treated with mitral valve interventions. However, approximately 10% remained on medical therapy alone and were considered as unsuitable for current transcatheter technologies. Mitral valve intervention was associated with a lower risk of HF rehospitalization and improved functional status.

Impact of left atrial appendage occlusion device position on potential determinants of device-related thrombus: a patient-specific in silico study.

BACKGROUND: Device-related thrombus (DRT) after left atrial appendage occlusion (LAAO) is potentially linked to adverse events. Although clinical reports suggest an effect of the device type and position on the DRT risk, in-depth studies of its mechanistic basis are needed. This in silico study aimed to assess the impact of the position of non-pacifier (Watchman) and pacifier (Amulet) LAAO devices on surrogate markers of DRT risk. METHODS: The LAAO devices were modeled with precise geometry and virtually implanted in different positions into a patient-specific left atrium. Using computational fluid dynamics, the following values were quantified: residual blood, wall shear stress (WSS) and endothelial cell activation potential (ECAP). RESULTS: In comparison to an ostium-fitted device position, deep implantation led to more residual blood, lower average WSS and higher ECAP surrounding the device, especially on the device's atrial surface and the surrounding tissue, suggesting increased risk for potential thrombus. For the non-pacifier device, an off-axis device orientation resulted in even more residual blood, higher ECAP and similar average WSS as compared to an ostium-fitted device position. Overall, the pacifier device showed less residual blood, higher average WSS and lower ECAP, compared to the non-pacifier device. CONCLUSIONS: In this in silico study, both LAAO device type and implant position showed an impact on potential markers of DRT in terms of blood stasis, platelet adhesion and endothelial dysfunction. Our results present a mechanistic basis for clinically observed risk factors of DRT and the proposed in silico model may aid in the optimization of device development and procedural aspects.

Symptomatic vs. non-symptomatic device-related thrombus after LAAC: a sub-analysis from the multicenter EUROC-DRT registry.

BACKGROUND: Device-related thrombus (DRT) after left atrial appendage closure (LAAC) is associated with adverse outcomes, i.e. ischemic stroke or systemic embolism (SE). Data on predictors of stroke/SE in the context of DRT are limited. AIMS: This study aimed to identify predisposing factors for stroke/SE in DRT patients. In addition, the temporal connection of stroke/SE to DRT diagnosis was analyzed. METHODS: The EUROC-DRT registry included 176 patients, in whom DRT after LAAC were diagnosed. Patients with symptomatic DRT, defined as stroke/SE in the context of DRT diagnosis, were compared against patients with non-symptomatic DRT. Baseline characteristics, anti-thrombotic regimens, device position, and timing of stroke/SE were compared. RESULTS: Stroke/SE occurred in 25/176 (14.2%) patients diagnosed with DRT (symptomatic DRT). Stroke/SE occurred after a median of 198 days (IQR 37-558) after LAAC. In 45.8% stroke/SE occurred within one month before/after DRT diagnosis (DRT-related stroke). Patients with symptomatic DRT had lower left ventricular ejection fractions (50.0 ± 9.1% vs. 54.2 ± 11.0%, p = 0.03) and higher rates of non-paroxysmal atrial fibrillation (84.0% vs. 64.9%, p = 0.06). Other baseline parameters and device positions were not different. Most ischemic events occurred among patients with single antiplatelet therapy (50%), however, stroke/SE was also observed under dual antiplatelet therapy (25%) or oral anticoagulation (20%). CONCLUSION: Stroke/SE are documented in 14.2% and occur both in close temporal relation to the DRT finding and chronologically independently therefrom. Identification of risk factors remains cumbersome, putting all DRT patients at substantial risk for stroke/SE. Further studies are necessary to minimize the risk of DRT and ischemic events.

Assessment of LAA Strain and Thrombus Mobility and Its Impact on Thrombus Resolution-Added-Value of a Novel Echocardiographic Thrombus Tracking Method.

PURPOSE: The mobility of left atrial appendage (LAA) thrombi and changes hereof under anticoagulation may serve as a marker of both risk of embolism and efficacy of treatment. In this study, we sought to evaluate thrombus mobility and hypothesized that LAA dynamics and thrombus mobility could serve as a baseline marker of thrombus dissolvability. METHODS: Patients with two-dimensional transesophageal echocardiographic images of the LAA, and with evidence of LAA thrombus were included in this study. Using a speckle tracking algorithm, functional information from the LAA and thrombi of different patients was computed. While the LAA motion was quantified through the longitudinal strain, thrombus mobility was evaluated using a novel method by directly tracking the thrombus, isolated from the global cardiac motion. Baseline characteristics and echocardiographic parameters were compared between responders (thrombus resolution) and non-responders (thrombus persistence) to anticoagulation. RESULTS: We included 35 patients with atrial fibrillation with evidence of LAA thrombi. Patients had a mean age of 72.9 ± 14.1 years, exhibited a high risk for thromboembolism (CHA2DS2-VASc-Score 4.1 ± 1.5) and had moderately reduced LVEF (41.7 ± 14.4%) and signs of diastolic dysfunction (E/E' = 19.7 ± 8.5). While anticoagulation was initiated in all patients, resolution was achieved in 51.4% of patients. Significantly higher LAA peak strain (- 3.0 ± 1.3 vs. - 1.6 ± 1.5%, p < 0.01) and thrombus mobility (0.33 ± 0.13 mm vs. 0.18 ± 0.08 mm, p < 0.01) were observed in patients in whom thrombi resolved (i.e. responders against non-responders). Receiver operating characteristic (ROC) analysis revealed a high discriminatory ability for thrombus mobility with regards to thrombus resolution (AUC 0.89). CONCLUSION: Isolated tracking of thrombus mobility from echocardiographic images is feasible. In patients with LAA thrombus, higher thrombus mobility appeared to be associated with thrombus resolution. Future studies should be conducted to evaluate the role of the described technique to predict LAA thrombus resolution or persistence.

Clinical and echocardiographic risk factors for device-related thrombus after left atrial appendage closure: an analysis from the multicenter EUROC-DRT registry.

BACKGROUND: Data on Device-related Thrombus (DRT) after left atrial appendage closure (LAAC) remain scarce. This study aimed to investigate risk factors for DRT from centers reporting to the EUROC-DRT registry. METHODS: We included 537 patients (112 with DRT and 425 without DRT) who had undergone LAAC between 12/2008 and 04/2019. Baseline and implantation characteristics, anti-thrombotic treatment and clinical outcomes were compared between both groups in uni- and multivariate analyses. Additional propensity-score matching (PSM) was conducted to focus on the role of implantation characteristics. RESULTS: Patients with DRT showed higher rates of previous stroke/transient ischemic attack (TIA) (49.1% vs. 34.7%, p < 0.01), spontaneous echocardiographic contrast (SEC) (44.9% vs. 27.7%, p < 0.01) and lower left atrial appendage (LAA) peak emptying velocity (35.4 ± 18.5 vs. 42.4 ± 18.0 cm/s, p = 0.02). Occluders implanted in DRT patients were larger (25.5 ± 3.8 vs. 24.6 ± 3.5 mm, p = 0.03) and implanted deeper in the LAA (mean depth: 7.6 ± 4.7 vs. 5.7 ± 4.7 mm, p < 0.01). Coverage of the appendage ostium was achieved less often in DRT patients (69.5% vs. 81.5%, p < 0.01), while DRT patients were less frequently on oral anticoagulation (7.1% vs. 16.7%, p < 0.01). Multivariate analysis identified age, prior stroke/TIA and SEC as independent risk factors for DRT. After PSM, implantation depth was found to be predictive. Rates of stroke/TIA were higher in DRT patients (13.5% vs. 3.8%, Hazard Ratio: 4.21 [95%-confidence interval: 1.88-9.49], p < 0.01). CONCLUSIONS: DRT after LAAC is associated with adverse outcome and appears to be of multifactorial origin, depending on patient characteristics, anticoagulation regimen and device position.

Clinical outcomes and thrombus resolution in patients with solid left atrial appendage thrombi: results of a single-center real-world registry.

BACKGROUND: Data on thrombus resolution and clinical outcome data after a therapy of LAA thrombus with novel oral anticoagulants (NOACs) are scarce. METHODS: In this single-center study, we retrospectively analyzed 78 patients diagnosed with a solid LAA thrombus by transesophageal echocardiography (TEE). We assessed baseline clinical and echocardiographic characteristics, the anticoagulatory regimens and outcomes of patients with (responders) and without (non-responders) thrombus resolution. RESULTS: Mean age was 76.1 ± 8.3 years, patients were male in 57.7% and presented with a high risk for thromboembolism (CHA2DS2-VASc: 4.3 ± 1.1). At thrombus diagnosis, 44.9% patients were treated with a NOAC, while 41.0% were under therapy with a VKA. Complete thrombus resolution was achieved after a mean of 116 ± 79 days in a total of 51.3% of patients, 35.9% showed a reduction of thrombus size, whereas 12.8% showed no changes in thrombus dimensions. There was no statistically significant difference in the rate of LAA thrombus resolution between VKA and NOACs (41.2 vs. 57.1%, p = 0.18). However, in cases in which only the therapy with a NOAC led to complete thrombus resolution, the time needed was significantly shorter than with VKA (81 ± 38 vs. 129 ± 46 days, p = 0.03). Regarding safety outcomes, no differences in bleeding or thromboembolism were observed between patients with and without thrombus resolution. CONCLUSIONS: In this registry, approximately 85% of LAA thrombi were diagnosed in patients with ongoing OAC. Thrombus resolution was observed in nearly 50% of cases. Although there was no difference in the rate of LAA thrombus resolution between VKA and NOACs, the resolution time was shorter in patients prescribed a NOAC.

Device-Related Thrombus After Left Atrial Appendage Closure: Data on Thrombus Characteristics, Treatment Strategies, and Clinical Outcomes From the EUROC-DRT-Registry.

BACKGROUND: Left atrial appendage closure is an established therapy in patients with atrial fibrillation. Although device-related thrombosis (DRT) is relatively rare, it is potentially linked to adverse events. As data on DRT characteristics, outcome, and treatment regimen are scarce, we aimed to assess these questions in a multicenter approach. METHODS: One hundred fifty-six patients with the diagnosis of DRT after left atrial appendage closure were included in the multinational EUROC-DRT registry. Baseline characteristics included clinical and echocardiographic data. After inclusion, all patients underwent further clinical and echocardiographic follow-up to assess DRT dynamics, treatment success, and outcome. RESULTS: DRT was detected after a median of 93 days (interquartile range, 54­161 days) with 17.9% being detected >6 months after left atrial appendage closure. Patients with DRT were at high ischemic and bleeding risk (CHA2DS2-VASc 4.5±1.7, HAS-BLED 3.3±1.2) and had nonparoxysmal atrial fibrillation (67.3%), previous stroke (53.8%), and spontaneous echo contrast (50.6%). The initial treatment regimens showed comparable resolution rates (antiplatelet monotherapy: 57.1%, dual antiplatelet therapy: 85.7%, vitamin K antagonists: 80.0%, novel oral anticoagulants: 75.0%, and heparin: 68.6%). After intensification or switch of treatment, complete DRT resolution was achieved in 79.5% of patients. Two-year follow-up revealed a high risk of mortality (20.0%) and ischemic stroke (13.8%) in patients with DRT. Patients with incomplete DRT resolution showed numerically higher stroke rates and increased mortality rates (stroke: 17.6% versus 12.3%, P=0.29; mortality: 31.3% versus 13.1%, P=0.05). CONCLUSIONS: A substantial proportion of DRT is detected >6 months after left atrial appendage closure, highlighting the need for imaging follow-up. Patients with DRT appear to be at a high risk for stroke and mortality. While DRT resolution was achieved in most patients, incomplete DRT resolution appeared to identify patients at even higher risk. Optimal DRT diagnostic criteria and treatment regimens are warranted.

Incidence, predictors, and relevance of acute kidney injury in patients undergoing left atrial appendage closure with Amplatzer occluders: a multicentre observational study.

AIMS: Acute kidney injury (AKI) remains a frequent complication after cardiac interventions, such as left atrial appendage closure (LAAC), yet limited data are available on the incidence and clinical implication of AKI in this setting. We sought to assess incidence, predictors and relevance of AKI after LAAC. METHODS AND RESULTS: We retrospectively analyzed 95 LAAC patients in three European centers. AKI was defined according to the Acute Kidney Injury Network (AKIN) classification. The incidence of AKI was 13.7% with mild AKI in 92.3% and AKI stage > II in 7.7%. Total contrast volume was not linked to the occurrence of AKI (AKI: 127 ± 83 vs. no AKI: 109 ± 92 ml, p = 0.41), however increasing contrast volume (CV) to glomerular filtration rate (GFR) ratio (CV/GFR ratio) was associated with an increased risk of AKI (OR, per unit increase: 1.24, 95% CI 0.97-1.58, p = 0.08). ROC-analysis revealed a moderate predictive value of CV/GFR ratio for the prediction of AKI (AUC: 0.67, 95% CI 0.50-0.84, p = 0.05). Furthermore, AKI was associated with significantly increased mortality 6 months and 1 year after LAAC. No significant difference in the incidence of AKI was observed between patients with mere fluoroscopic and additional echocardiographic guidance (16.3% vs. 11.5%, p = 0.56). CONCLUSION: Whereas mild AKI is common in patients after LAAC, severe AKI is rare. AKI after LAAC is associated with poor baseline renal function, increased doses of contrast (CV/GFR ratio) and impaired outcome. Future studies will be needed to elaborate the benefit of reducing or avoiding contrast volume regarding this endpoint.

Contrast-free, echocardiography-guided left atrial appendage occlusion (LAAo): a propensity-matched comparison with conventional LAAo using the AMPLATZER™ Amulet™ device.

AIMS: Percutaneous left atrial appendage occlusion (LAAo) is commonly performed under fluoroscopy including the use of contrast dye. In this study, we aimed to assess feasibility and safety of contrast-free, 3D-echo-based LAAo with the use of the AMPLATZER™ Amulet™ device. METHODS AND RESULTS: We analyzed 20 patients (74 ± 10 years, 65% males) at an increased thromboembolic and bleeding risk (CHA2DS2VASC 4.0 ± 1.3; HAS-BLED 3.5 ± 0.9) with chronic renal failure (GFR 41 ± 21 ml/min) undergoing LAAo without the use of contrast dye at our center and compared the results with a propensity-matched cohort (1:1 matching) of conventionally treated patients receiving contrast agent. Contrast-free LAAo was associated with less radiation exposure (13.1 ± 19.2 vs. 32.9 ± 21.2 Gy*cm2, p < 0.01) and fluoroscopy time (5.0 ± 3.4 vs. 11.6 ± 4.9 min, p < 0.01). Procedural success rates were excellent in both groups (100%) without severe periprocedural complications (i.e. procedural death, stroke/systemic embolism, myocardial infarction, cardiac tamponade or major bleeding). CONCLUSIONS: Echocardiographically guided LAAo without the use of contrast dye appears safe and feasible. This approach appears to be associated with reduced radiation exposure and may represent an alternative to traditional LAAo, especially in patients in whom the avoidance of contrast dye is warranted.