Predictors of thrombus formation after percutaneous left atrial appendage closure using the WATCHMAN device

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.

A comparison of simplified or conventional antithrombotic regimens after left atrial appendage closure in patients at high bleeding risk: the PLATEBRISK study

BACKGROUND

Antithrombotic treatment (ATT) post-left atrial appendage occlusion (LAAO) remains controversial. Furthermore, most of the patients undergoing LAAO are at a very high bleeding risk.

AIMS

This study aimed to compare a simplified versus conventional ATT after LAAO in very high bleeding risk patients.

METHODS

This is a multicentre, retrospective study including very high bleeding risk patients, according to the Bleeding Academic Research Consortium (BARC) definition, who underwent LAAO. These included patients at >4% risk of BARC 3 to 5 bleeding or >1% risk of intracranial bleeding after the procedure. Two groups were established based on the discharge ATT. The simplified group included single antiplatelet treatment or no treatment, and the conventional group comprised dual antiplatelet treatment or anticoagulation (combined or not with antiplatelet therapy).

RESULTS

A total of 1,135 patients were included. The mean CHA2DS2-VASc and HAS-BLED scores were 4.5±1.5 and 3.7±1.0, respectively. There were no differences in the composite endpoint (death, stroke, transient ischaemic attack, device-related thrombus or major bleeding) between the 2 groups (hazard ratio [HR] 0.81, 95% confidence interval [CI]: 0.59-1.11; p=0.188). Although the rate of major bleeding during the first year was numerically lower in the simplified group, it did not reach statistical significance (HR 0.67, 95% CI: 0.41-1.10; p=0.104). Nonetheless, patients with previous major bleeding presented a significantly lower rate of major bleeding when using the simplified treatment (HR 0.61, 95% CI: 0.36-0.99; p=0.049).

CONCLUSIONS

In patients with very high bleeding risk, a simplified ATT after LAAO seems to be as effective as conventional protocols. Furthermore, patients with a history of major bleeding experienced a lower risk of major bleeding with the simplified ATT.

Incidence of Acute Thrombosis After Surgical Left Atrial Appendage Occlusion for Atrial Fibrillation

BACKGROUND

The clinical implications of acute phase thrombosis after surgical left atrial appendage (LAA) closure remain unclear. This study sought to determine the frequency, prognosis, and factors involved in thrombogenesis after surgical LAA occlusion.

METHODS

In this study, data from patients who underwent 2 types of standalone surgical LAA closure (either resection or clipping) between July 2014 and March 2020 at a single center were analyzed.

RESULTS

A total of 239 consecutive patients with atrial fibrillation underwent minimally invasive standalone surgical LAA occlusion (184 resection cases and 55 clipping cases). On postoperative day 2, electrocardiogram synchronized contrast-enhanced computed tomography (CT) was performed in 223 cases (93.3%), and echocardiography follow-up was performed in 16 cases when CT was contraindicated. Acute postoperative thrombus on the closed stump was detected in 35 cases (14.7%), of which 29 cases (15.8%) belonged to the resection group and 6 cases (10.9%) belonged to the clipping group. No significant difference was detected between the groups, and no significant predictors of acute-phase thrombosis were found. Thromboembolism occurred in 4 patients before postoperative imaging follow-up, and there was no evidence of thrombi in these patients on postoperative day 2 CT. Three months after the first CT, thrombi were no longer detected in 34 of 35 patients (97.1%).

CONCLUSIONS

Thrombosis can occur after surgical LAA occlusion. Although the clinical significance is yet unclear, it may be reasonable to continue anticoagulation therapy until a lack of thrombosis is confirmed, unless there are contraindications.

Left Atrial Appendage Occlusion and Post-procedural Antithrombotic Management

Left atrial appendage occlusion (LAAO) is an established alternative to oral anticoagulation for stroke prevention in atrial fibrillation. Antithrombotic therapy is used in the post-procedural period to prevent device-related thrombosis (DRT). The risk of DRT is considered highest in the first 45-90 days after device implantation, based on animal studies of the device healing process. Clinically applied antithrombotic regimens vary greatly across studies, continents, and centers. This article gives an overview of the evidence behind current antithrombotic regimens, ongoing randomized trials, and future post-procedural management.

Is spontaneous echo contrast associated with device-related thrombus or embolic events after left atrial appendage occlusion? - Insights from the multicenter German LAARGE registry

BACKGROUND

Interventional left atrial appendage occlusion (LAAO) provides an alternative to oral anticoagulation (OAC) for prophylaxis of thromboembolic events (TEs) in nonvalvular atrial fibrillation patients, predominantly in those with high bleeding risk and contraindications for long-term OAC. Although spontaneous echo contrast (SEC) is a well-known risk factor for atrial thrombus formation, little is known about whether this means an increased risk of device-related thrombus (DRT) or TEs following LAAO.

METHODS

This substudy of the prospective, multicenter German LAARGE registry assessed two groups according to absence (SEC -) or presence of SEC (SEC +) in preprocedural cardiac imaging. Clinical and echocardiographic parameters were registered up to 1 year after LAAO.

RESULTS

Five hundred eighty-eight patients (SEC - 85.5 vs. SEC + 14.5%) were included. More SEC + patients were implanted for OAC non-compliance (11.8 vs. 4.6%, p = 0.008) and a higher proportion received only antiplatelet therapy without OAC at hospital discharge (96.5 vs. 86.0%, p = 0.007). The SEC + patients had larger LA diameters (50 (47; 54) vs. 47 (43; 51) mm, p < 0.001), wider LAA ostia (21 (19; 23) vs. 20 (17; 22) mm at 45°, p = 0.011), and lower left ventricular ejection fraction (50 (45; 60) vs. 60 (50; 60) %, p < 0.001) on admission. Procedural success was very high in both groups (98.1%, p = 1.00). Periprocedural major adverse cardiac and cerebrovascular events and other major complications were rare in both groups (3.8 vs. 4.7%, p = 0.76). At follow-up, DRT was only detected in the SEC - group (3.8 vs. 0%, p = 1.00). The rates of TEs (SEC - 1.2 vs. SEC + 0%, p = 1.00) after hospital discharge and 1-year mortality (SEC - 12.0 vs. SEC + 11.8%, p = 0.96) were not significantly different between the two groups.

CONCLUSIONS

Presence of SEC at baseline was not associated with an increased rate of DRT or TEs at 1-year follow-up after LAAO in LAARGE.

Device-Related Thrombus After Left Atrial Appendage Occlusion: Clinical Impact, Predictors, Classification, and Management

Despite the unprecedented advances in the left atrial appendage occlusion field, device-related thrombus (DRT) remains an unresolved issue with the therapy. This paper aims to provide a state-of-the-art review of the literature on the incidence, clinical impact, predictors and management of DRT and propose a novel classification of DRT and hypoattenuated thickening.

Impact and predictors of device-related thrombus after percutaneous left atrial appendage closure

Device-related thrombus (DRT) is a known complication occurring in up to 7% of patients undergoing percutaneous left atrial appendage closure (LAAC). Since the target population of LAAC is generally ineligible for oral anticoagulant therapies, DRT raises important concerns. The aim of this review will be to summarize available evidence on DRT after LAAC focusing on its possible impact on outcomes. Recent findings showed a tighter association between DRT and neurological ischemic events. Antithrombotic regimen adopted after LAAC may have a protective effect against DRT. Many patient-related and procedural factors have been identified as possible predictors of DRT. A tailored approach, which takes into account DRT, is needed in the patient selection for LAAC and in the postprocedural follow-up.

Predictive Power for Thrombus Detection after Atrial Appendage Closure: Machine Learning vs. Classical Methods

Device-related thrombus (DRT) after left atrial appendage (LAA) closure is infrequent but correlates with an increased risk of thromboembolism. Therefore, the search for DRT predictors is a topic of interest. In the literature, multivariable methods have been used achieving non-consistent results, and to the best of our knowledge, machine learning techniques have not been used yet for thrombus detection after LAA occlusion. Our aim is to compare both methodologies with respect to predictive power and the search for predictors of DRT. To this end, a multicenter study including 1150 patients who underwent LAA closure was analyzed. Two lines of experiments were performed: with and without resampling. Multivariate and machine learning methodologies were applied to both lines. Predictive power and the extracted predictors for all experiments were gathered. ROC curves of 0.5446 and 0.7974 were obtained for multivariate analysis and machine learning without resampling, respectively. However, the resampling experiment showed no significant difference between them (0.52 vs. 0.53 ROC AUC). A difference between the predictors selected was observed, with the multivariable methodology being more stable. These results question the validity of predictors reported in previous studies and demonstrate their disparity. Furthermore, none of the techniques analyzed is superior to the other for these data.

Comparative analysis of left atrial appendage closure efficacy and outcomes by CHA2DS2-VASc score group in patients with non-valvular atrial fibrillation

Background

Higher CHA₂DS₂-VASc score is associated with an increased risk of adverse cardio-cerebrovascular events in patients with non-valvular atrial fibrillation (NVAF), regardless of oral anticoagulation (OAC) status. However, whether this association still exists in patients undergoing left atrial appendage closure (LAAC) is unknown. We evaluated the impact of CHA₂DS₂-VASc score on LAAC efficacy and outcomes.

Methods

A total of 401 consecutive patients undergoing LAAC were included and divided into 3 groups based on CHA₂DS₂-VASc score (0–2, 3–4, and ≥5). Baseline characteristics, periprocedural complications, and long-term outcomes were collected and compared across all groups.

Results

There were no significant differences in implantation success, periprocedural complications, and long-term outcomes across all score groups. Kaplan-Meier estimation showed that the cumulative ratio of freedom from all-cause mortality (P = 0.146), cardiovascular mortality (P = 0.519), and non-cardiovascular mortality (P = 0.168) did not differ significantly by CHA₂DS₂-VASc score group. LAAC decreased the risks of thromboembolism and major bleeding, resulting in a relative risk reduction (RRR) of 82.4% (P < 0.001) and 66.7% (P < 0.001) compared with expected risks in the overall cohort, respectively. Subgroup analysis indicated that observed risks of thromboembolism and major bleeding were significantly lower than the expected risks in score 3–4 and score ≥5 groups, respectively. The level of RRR increased with CHA₂DS₂-VASc score (P < 0.001 for trend) for thromboembolism but not for major bleeding (P = 0.2729 for trend).

Conclusion

Patients with higher CHA₂DS₂-VASc score did not experience worse outcomes, which may be partly attributed to more benefits provided by LAAC intervention in such patients compared to those with a low score.

Device-related thrombus following left atrial appendage occlusion

Thrombus formation on intracardiac devices remains a subject of importance, with rates in the 2-5% range. Device-related thrombus (DRT) following left atrial appendage occlusion is an area of particular concern considering its association with embolic events. DRT continues to present numerous questions, including the optimal definition, incidence, risk factors, monitoring, therapy, and clinical outcomes - all subjects of ongoing assessment. Herein, we discuss these considerations, building upon the relevant historical context and pathophysiologic insights while discussing the future considerations in this rapidly evolving field.

The ALSTER-FLX Registry: 3-month outcomes following left atrial appendage occlusion employing a next-generation device, a matched-pair-analysis to EWOLUTION

BACKGROUND

The new generation WATCHMAN FLX device for left atrial appendage occlusion has been modified in various aspects to improve procedural results. No comparison of the WATCHMAN FLX to the previous WATCHMAN device is available.

OBJECTIVES

We aimed to compare procedural results with WATCHMAN FLX in patients on dual antiplatelet therapy at around three months to data with WATCHMAN (EWOLUTION registry).

METHODS

164 consecutive patients receiving the WATCHMAN FLX device in four European centers were included in the retrospective ALSTER FLX registry. As a control-group for a matched-pair-analysis, 1020 patients treated with the WATCHMAN device and data up to first follow-up (around three months) from the EWOLUTION registry were used.

RESULTS

Implantation was successful in all ALSTER FLX patients (100%) and similar to results in EWOLUTION (99%, p=0.2). We observed no stroke or device embolization in ALSTER FLX, similar to EWOLUTION (stroke 0.5%, device embolization 0.4%) at three months. Numerically less ALSTER FLX patients (2.4%) developed a device associated thrombus (DAT) compared to 3.7% EWOLUTION patients, yet without reaching statistical significance after matching (DAT pairwise event-difference median, 95% confidence interval 2(0/6), p=0.1). WATCHMAN FLX implantation was associated with a significant higher sealing rate compared to EWOLUTION at three months (ALSTER FLX 90% vs. EWOLUTION 79.4%, p=0.039 after matching). Major non-procedural bleeding events and mortality were similar after matching (event difference for bleeding 0(-3/3), p=0.6; death (1(-2/4), p=0.3).

CONCLUSIONS

Periprocedural, early 3-months outcomes with WATCHMAN FLX demonstrate a similar safety profile and an improved sealing rate compared to the WATCHMAN device.

Predictors of Device-Related Thrombus Following Percutaneous Left Atrial Appendage Occlusion

BACKGROUND

Device-related thrombus (DRT) has been considered an Achilles' heel of left atrial appendage occlusion (LAAO). However, data on DRT prediction remain limited.

OBJECTIVES

This study constructed a DRT registry via a multicenter collaboration aimed to assess outcomes and predictors of DRT.

METHODS

Thirty-seven international centers contributed LAAO cases with and without DRT (device-matched and temporally related to the DRT cases). This study described the management patterns and mid-term outcomes of DRT and assessed patient and procedural predictors of DRT.

RESULTS

A total of 711 patients (237 with and 474 without DRT) were included. Follow-up duration was similar in the DRT and no-DRT groups, median 1.8 years (interquartile range: 0.9-3.0 years) versus 1.6 years (interquartile range: 1.0-2.9 years), respectively (P = 0.76). DRTs were detected between days 0 to 45, 45 to 180, 180 to 365, and >365 in 24.9%, 38.8%, 16.0%, and 20.3% of patients. DRT presence was associated with a higher risk of the composite endpoint of death, ischemic stroke, or systemic embolization (HR: 2.37; 95% CI, 1.58-3.56; P < 0.001) driven by ischemic stroke (HR: 3.49; 95% CI: 1.35-9.00; P = 0.01). At last known follow-up, 25.3% of patients had DRT. Discharge medications after LAAO did not have an impact on DRT. Multivariable analysis identified 5 DRT risk factors: hypercoagulability disorder (odds ratio [OR]: 17.50; 95% CI: 3.39-90.45), pericardial effusion (OR: 13.45; 95% CI: 1.46-123.52), renal insufficiency (OR: 4.02; 95% CI: 1.22-13.25), implantation depth >10 mm from the pulmonary vein limbus (OR: 2.41; 95% CI: 1.57-3.69), and non-paroxysmal atrial fibrillation (OR: 1.90; 95% CI: 1.22-2.97). Following conversion to risk factor points, patients with ≥2 risk points for DRT had a 2.1-fold increased risk of DRT compared with those without any risk factors.

CONCLUSIONS

DRT after LAAO is associated with ischemic events. Patient- and procedure-specific factors are associated with the risk of DRT and may aid in risk stratification of patients referred for LAAO.

Device-Related Thrombosis in Patients Receiving One-Stop Intervention for Nonvalvular Atrial Fibrillation: A Systemic Review and Meta-Analysis

This study aimed to assess the incidence, clinical implications, and treatment strategies of device-related thrombus (DRT) following catheter ablation and percutaneous left atrial appendage occlusion combined in one intervention. A meta-analysis of observational studies was conducted to evaluate the incidence rates, treatment strategies, and clinical implications of DRT. A total of 21 studies describing DRT events and 1 case were included in the current study. The 21 included studies comprised 3 multi-center registries and 18 single-center registries, and we also included 1 case report analyzing the characteristics of DRT. The pooled incidence of DRT in one-stop intervention was 18/1,708 (1.2%; range = 0%-7.3%; 95% CI = 0.7%-1.8%; I 2 = 0). Of these DRT events, 56.25% were diagnosed in the first 3 months after the procedure. All cases were diagnosed via trans-esophagus echocardiogram. All of the patients diagnosed with DRT were prescribed anticoagulation treatment, and 63% (12/19) of the events were reported with an outcome of complete thrombus resolution. The duration of anticoagulation treatment varied greatly, from 30 days to 6 months. Unknown clinical events were reported relating to DRT. Device-related thrombus is an uncommon complication of one-stop intervention. It occurs mainly in the early period following the procedure. Anticoagulation appears to be an appropriate treatment method for dissolving occurrences of DRT.

Women and atrial fibrillation

Atrial fibrillation (AF) remains a growing problem in the United States and worldwide, imposing a high individual and health system burden, including increased resource consumption due to repeated hospitalizations, stroke, dementia, heart failure, and death. This comprehensive review summarizes the most recent data on sex-related differences in risks associated with AF. Women with AF have increased risk of stroke and death compared to men, and possible reasons for this disparity are explored. Women also continue to have worse symptoms and quality of life, and poorer outcomes with stroke prevention, as well as with rate and rhythm control management strategies. Many current rhythm control treatment strategies for AF, including cardioversion and ablation, are used less frequently in women as compared to men, whereas women are more likely to be treated with rate control strategies or antiarrhythmic drugs. Sex differences should be considered in treating women with AF to improve outcomes and women and men should be offered the same interventions for AF. We need to improve the evidence base to understand if variation in utilization of rate and rhythm control management between men and women represents health inequities or appropriate clinical judgement.

Closure Device-Related Thrombosis After Anticoagulation With Dabigatran in Patients Undergoing Percutaneous Left Atrial Appendage Closure: Case Reports and Literature Review

Percutaneous left atrial appendage closure (LAAC) is an effective and safe operation strategy for stroke prevention in patients who are diagnosed with atrial fibrillation (AF) but cannot tolerate long term anticoagulation medication. We presented four rare cases of thrombosis formation on the occluder device. After the LAAC operation was successfully performed on patients, they followed a course of anticoagulation with dabigatran (110 mg b.i.d.), and device-related thrombosis (DRT) occurred as indicated by a transesophageal echocardiogram (TEE) during the follow-up period. Regressions were achieved after replacing dabigatran with rivaroxaban or warfarin for more than 1 month. No thrombosis or bleeding-related complications occurred in subsequent follow-ups.

Acute Device-Related Thrombus after Watchman Device Implant

Atrial fibrillation is characterized by irregularly irregular heart rhythm with an increased morbidity and mortality. It is associated with an increased risk of thromboembolism due to formation of blood clot in the left atrium. Most of these blood clots are formed in the left atrial appendage. The risk of blood clot formation is reduced with the use of anticoagulants. The patients who cannot take anticoagulants due to an increased bleeding risk can undergo percutaneous left atrial appendage (LAA) closure. A Watchman device is used for this purpose. LAA closure with the Watchman device is associated with some adverse effects, and one of them is device-related thrombus. Currently, there are no specific guidelines for the management of device-related thrombus. We present a case of Watchman device-related thrombus which developed 16 hours after the device placement. We will also discuss various options for the management of acute thrombosis.

Device-Related Thrombus After Left Atrial Appendage Closure: Incidence, Predictors, and Outcomes

BACKGROUND

In patients with atrial fibrillation, left atrial appendage closure with the Watchman device prevents thromboembolism from the left atrial appendage; however, thrombus may form on the left atrial face of the device, and then potentially embolize. Herein, we studied the incidence, predictors, and clinical outcome of device-related thrombus (DRT) using a large series of clinical trial cohorts of patients undergoing Watchman implantation.

METHODS

We studied the device arms of 4 prospective Food and Drug Administration trials: PROTECT-AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) (n=463); PREVAIL (Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy) (n=269); CAP (Continued Access to PROTECT AF registry) (n=566); and CAP2 (Continued Access to PREVAIL registry) (n=578). Surveillance transesophageal echocardiographs were performed at 45 days and 12 months in all patients, and also at 6 months in the randomized control trials. We assessed both the incidence of DRT during these transesophageal echocardiographs (and other unscheduled transesophageal echocardiographs), and clinical outcomes of postprocedure stroke or systemic embolism (SSE) and adjusted for CHA₂DS₂-VASC and HAS-BLED scores.

RESULTS

Of 1739 patients who received an implant (7159 patient-years follow-up; CHA₂DS₂-VASc=4.0), DRT was seen in 65 patients (3.74%). The rates of SSE with and without DRT were 7.46 and 1.78 per 100 patient-years (adjusted rate ratio, 3.55; 95% confidence interval [CI], 2.18-5.79; P<0.001), and ischemic SSE rates were 6.28 and 1.65 per 100 patient-years (adjusted rate ratio, 3.22; 95% CI, 1.90-5.45, P<0.001). On multivariable modeling analysis, the predictors of DRT were as follows: history of transient ischemic attack or stroke (odds ratio [OR], 2.31; 95% CI, 1.26-4.25; P=0.007), permanent atrial fibrillation (OR, 2.24; 95% CI, 1.19-4.20; P=0.012); vascular disease (OR, 2.06; 95% CI, 1.08-3.91; P=0.028); left atrial appendage diameter (OR, 1.06 per mm increase; 95% CI, 1.01-1.12; P=0.019); left ventricular ejection fraction (OR, 0.96 per 1% increase; 95% CI, 0.94-0.99; P=0.009). DRT and SSE both occurred in 17 of 65 patients (26.2%). Of the 19 SSE events in these patients with DRT, 9 of 19 (47.4%) and 12 of 19 (63.2%) occurred within 1 and 6 months of DRT detection. Conversely, after left atrial appendage closure, most SSEs (123/142, 86.62%) occurred in patients without DRT.

CONCLUSIONS

After left atrial appendage closure with Watchman, DRT (≈3.7%) is not frequent but, when present, is associated with a higher rate of stroke and systemic embolism.

Device Thrombosis After Percutaneous Left Atrial Appendage Occlusion Is Related to Patient and Procedural Characteristics but Not to Duration of Postimplantation Dual Antiplatelet Therapy

BACKGROUND

Device-related thrombus (DRT) after left atrial appendage occlusion is a worrisome finding with little knowledge about when to expect it and how to prevent it. This study sought to investigate correlates of DRT after left atrial appendage occlusion, its time of diagnosis, and particularly, association with postimplantation dual antiplatelet therapy duration.

METHODS AND RESULTS

Consecutive patients (n=102) after left atrial appendage occlusion with AMPLATZER Cardiac Plug/Amulet (n=59) or WATCHMAN (n=43) were included in a prospective registry (October 2011-May 2016). Follow-up was done at 1.5, 3 to 6, and 12 months postimplantation. DRT was classified as early (at 1.5 month), late (at 3-6 month), or very late (at 12-month follow-up). Postimplantation dual antiplatelet therapy was recommended for 30 to 180 days and decided independently by attending physicians. Final analysis included 99 patients, 42 (42.4%) females, with median CHA₂DS₂-VASc of 4.0 (interquartile range [IQR], 3.0-5.0) and median HAS-BLED score of 2.0 (IQR, 1.0-3.0). DRTs were observed in 7 (7.1%) patients: 2 (28.6%) early, 2 (28.6%) late, and 3 (42.9%) very late. When compared with patients without DRT, those with DRT presented more often with a history of prior thromboembolism (5 [71.4%] versus 28 [30.4%]; P=0.04), had lower left ventricular ejection fraction (50.0 [IQR, 35.0-55.0] versus 60.0 [IQR, 55.0-66.0]; P<0.01), and had greater proportion of patients with deep device implantation (6 [85.7%] versus 36 [39.1%]; P=0.04) and with larger devices implanted (30.0 mm [IQR, 27.0-33.0] versus 25.0 mm [IQR, 24.0-28.0]; P<0.01). Postimplantation dual antiplatelet therapy duration was not different between the 2 groups (12.4 weeks [IQR, 6.0-49.7] with DRT versus 13.0 weeks [IQR, 7.3-26.0] without DRT; P=0.77).

CONCLUSIONS

In this real-world series, DRT was observed early, late, and very late after left atrial appendage occlusion. It was related to patient and procedural characteristics but not to postimplantation dual antiplatelet therapy duration.

Antithrombotic/Antiplatelet Treatment in Transcatheter Structural Cardiac Interventions-PFO/ASD/LAA Occluder and Interatrial Shunt Devices

Transcatheter interventions enable safe and efficient treatment of various structural heart diseases. However, therapy does not finished with the end of the procedure. Device thrombosis is a possible serious complication. Therefore, careful patient management should include optimal antiplatelet or antithrombotic medication to enhance safe and complete endothelial coverage of the implanted device. In case of thrombus formation careful diagnostic evaluation and prompt treatment is crucial. This paper provides an update to current knowledge and understanding of prevention and management of device related thrombosis.

Cerebrovascular events, bleeding complications and device related thrombi in atrial fibrillation patients with chronic kidney disease and left atrial appendage closure with the WATCHMAN™ device

BACKGROUND

Impaired renal function increases the bleeding risk, leading to a conservative prescription and frequent discontinuation of oral anticoagulation in atrial fibrillation patients with chronic kidney disease (CKD). Interventional left atrial appendage closure (LAAC) might be an alternative therapeutic strategy for these patients.

METHODS

We aimed to prospectively assess cerebrovascular (CE) and bleeding events, as well as peri-procedural and long-term complications in a cohort of consecutive patients undergoing interventional LAAC using the WATCHMAN™ device, with focus on CKD patients.

RESULTS

One hundred and eighty-nine consecutive patients undergoing interventional LAAC were included in this analysis; 171 (90.5%) patients had a reduced estimated glomerular filtration rate (eGFR; patients for each CKD stage: II = 66; IIIa = 32; IIIb = 43; IV = 18; V = 12). During a follow-up of 310 patient years three (1.0%) patients suffered a CE (two strokes, one transitory ischemic attack) and five (1.6%) other ones a bleeding complication. The observed stroke rate was more than two-thirds and the bleeding risk more than half lower than expected. Device related thrombi (DRT) were detected in twelve (6.5%) patients; women had significantly more DRT than men (12.5% vs. 2.6%; p = 0.009). Patients with an eGFR< 30 ml/min/1.73m2 showed a trend to a higher DRT rate as compared to the opposite group (13.3% vs. 5.1%; p = 0.10). Thrombus resolved with temporary oral anticoagulation therapy in ten patients without sequelae; thrombus consolidation was confirmed by serial TEE controls in the remaining two patients.

CONCLUSIONS

Atrial fibrillation patients with CKD have low CE and bleeding rates after LAAC with the WATCHMAN™ device. DRT risk is higher in female and patients with severe CKD. More frequent post-interventional TEE controls might be justified for early DRT detection and safe management of patients at high DRT risk.

TRIAL REGISTRATION

(German Clinical Trials Register ID: DRKS00 010768 ; Registration Date 07.07.2016).

Gender Differences in Atrial Fibrillation: A Review of Epidemiology, Management, and Outcomes

Atrial fibrillation is the most common sustained cardiac arrhythmia. The scope and impact of atrial fibrillation are wide; it can affect cardiac function, functional status, and quality of life, and it confers a stroke risk. There are sex differences in atrial fibrillation across the scope of the disease process, from epidemiology and causative mechanisms to management and outcomes. The approach to management of atrial fibrillation differs between women and men, and there are sex differences in response to medical therapy and catheter ablation. There are many gaps in our knowledge of the gender differences in atrial fibrillation, and many opportunities for future research.

Real-world survival data of device-related thrombus following left atrial appendage closure: 4-year experience from a single center

This study aimed to estimate the incidence and risk factors of device-related thrombus (DRT) following percutaneous left atrial appendage closure (LAAC) in real-world practices. Between February 2012 and December 2016, 319 consecutive patients with atrial fibrillation underwent percutaneous LAAC using WATCHMAN, WATCHMAN Flx, Amplatzer cardiac plug, and Amulet devices. All patients underwent transesophageal echocardiography (TEE) at a minimum of three time points; periprocedurally, at 45 days, and at 6 months. Other clinical parameters were also evaluated, and a comparison between patients with DRT and those not suffering from DRT was done. The percutaneous LAAC was successfully performed in 97.8% of the patients. DRT was detected in 14 (4.49%) patients; of the 14 patients, DRT was detected in 3 patients at acute phase, 8 patients at subacute phase, 2 patients at late phase and 1 patient at very late phase. Most of the DRT originated from the central screw of device. In 6 out of 14 patients, DRT was successfully resolved by oral anticoagulation. Higher HAS-BLED score (4.1 ± 1.2 vs. 3.5 ± 1.1, p = 0.042) was more frequent in patients with DRT. Multivariable analysis showed that residual peri-device leak may result in a predisposition to DRT (p = 0.023). The incidence of DRT after percutaneous LAAC was acceptable, as a part of the DRT was resolved with oral anticoagulation. Residual peri-device leak was associated with DRT. Optimal implantation without peri-device gap, individual antithrombotic regimens, and careful monitoring with TEE follow-up could be conducive to the prevention of DRT.

Incidence and Clinical Impact of Device-Related Thrombus Following Percutaneous Left Atrial Appendage Occlusion: A Meta-Analysis

OBJECTIVES

This study sought to assess the incidence and clinical impact of device related thrombus (DRT) following precautions left atrial appendage occlusion (LAAO).

BACKGROUND

Device-related thrombus is a known complication of LAAO. However, data on the incidence of DRT and its impact on outcomes are limited.

METHODS

The authors performed a meta-analysis of randomized and observational studies to calculate the pooled incidence of DRT and the pooled odds ratio (OR) of ischemic events in patients with DRT and those without DRT.

RESULTS

In the 66 included studies; the incidence of DRT was 351/10, 153 (3.8%, range 0% to 17%, I² = 56.8). The diagnosis was made in <90, 90 to 365, and >365 days in 42%, 57%, and 1% of patients, respectively. There was no difference in DRT rates between the AMPLATZER (AMPLATZER, AGA Medical Corporation, Golden Valley, Minnesota) and WATCHMAN (WATCHMAN, Boston Scientific Corporation, Marlborough, Massachusetts) devices (3.6% vs. 3.1%, p = 0.24). In a meta-regression, age, gender, heart failure, diabetes, CHA₂DS₂-VASc score, previous stroke, and post-LAAO antithrombotic regimen did not explain the heterogeneity in the incidence of DRT. The pooled incidence of ischemic events in studies that compared outcomes of patients with and without DRT (32 studies; n = 7,689) was 13.2% (37 of 280) in patients with DRT and 3.8% (285 of 7,399) in those without DRT (OR: 5.27, 95% confidence interval [CI]: 3.66 to 7.59; p < 0.001, I² = 0). In a sensitivity analysis including randomized trials and prospective multicenter registries, the incidence of DRT was 3.7%, and DRT remained associated with higher rates of ischemic events (13.5% vs. 4.4%, OR: 4.15, 95% CI: 2.77 to 6.22; p < 0.001, I² = 0).

CONCLUSIONS

DRT after LAAO is uncommon (3.8%) but is associated with a 4- to 5-fold increase in ischemic events. Further studies are needed to understand the underlying mechanisms and the optimal surveillance and management of DRT.

Bleeding in advanced CKD patients on antithrombotic medication - A critical appraisal

Patients with advanced chronic kidney disease (CKD) are at an increased risk of bleeding, especially in the context of the complex therapeutic schemes of coronary artery disease (CAD) (from stable angina to acute coronary syndromes), atrial fibrillation or venous thromboembolism. The bleeding issue increases morbidity and mortality, a serious problem in daily medical practice. However, these patients are largely excluded from major randomized clinical trials, which results in the lack of medical evidence-based foundation for specific recommendations regarding antithrombotic treatment in a high bleeding risk setting. Within this framework, the clinician does not benefit from a clear set of algorithms and measures in the exploration and balancing of bleeding and thrombosis risks. We discuss a diversity of scenarios, encompassing all categories of advanced CKD patients with CAD or/and atrial fibrillation, and with various combinations of drugs, such as antiplatelet therapy or/and oral anticoagulation. Our review highlights the most recent research as well as existing gaps in the recommendations of European Society of Cardiology Guidelines. We evaluate the existence or lack of assessment tools for the bleeding risk, strength, reliability and usefulness of the bleeding risk scores. Also, we identify all the measures recommended after risk evaluation, including specific plans, dose adjustments and particular therapeutic approaches. Finally, we provide with suggestions for improving the management of this patient population.