Discriminating factors excluding patients from a catheter-based left atrial appendage closure and an outcome analysis of non-intervened and intervened patients.

Introduction: The catheter-based left atrial appendage closure (LAAC) has evolved as an alternative to oral anticoagulation (OAC) among non-valvular atrial fibrillation (AF) patients in whom long-term OAC is contraindicated. In daily practice, however, a sizeable number of patients who have been referred for an LAAC do not receive this intervention. This study aimed primarily to investigate the factors deterring the practice of an LAAC in referred AF patients, and secondarily to compare the complication rates of intervened patients with those who had refused the intervention within 1 year. Material and methods: This retrospective single-centre study includes 200 patients. After a thoroughly conducted clinical selection process, 161 of these patients (80.5%) were excluded from receiving an LAAC intervention. Results: An analysis comparing these patients to those receiving an LAAC reveales that a higher proportion of intervened patients had suffered a prior gastrointestinal bleeding (48.7 vs. 28.0%; p = 0.013) as well as a haemorrhagic stroke (12.8 vs. 2.5%; p = 0.015), and was not anticoagulated at the time of presentation (35.9 vs. 14.9%; p = 0.006). The main reason for not conducting the procedure was patient refusal (62.1%) followed by multimorbidity (16.8%). The annual rate of ischaemic strokes and bleedings among patients refusing the intervention was 2.1% and 29.5%, respectively, and this was not statistically different from the intervened patients (each p > 0.05). Conclusions: The reasons why patients did not undergo the catheter-based LAAC were mainly reluctance for the procedure and multimorbidity. Furthermore, it could be assumed that the potential benefit of the LAAC may not be realised within the first year.

Incomplete neo-endothelialization of left atrial appendage closure devices is frequent after 6 months: a pilot imaging study.

PURPOSE: To bridge neo-endothelialization (NE) of implanted left atrial appendage closure (LAA/LAAC) devices, dual antiplatelet therapy is prescribed. Cardiac computed tomography angiography (cCTA) has been proposed for the evaluation of interventional LAAC. This prospective longitudinal observational study applied a standardized imaging protocol to detect progression of NE of LAAC devices 6 months after implantation. METHODS: Consecutive cCTA datasets of patients six months after LAAC were acquired and the standardized multi-planar reconstruction LAA occluder view for post-implantation evaluation (LOVE) algorithm was used. Residual flow of contrast agent inside the LAA without a peri-device leak (PDL) was defined as incomplete neo-endothelialization. Absence of residual flow was defined as complete neo-endothelialization. Since PDL allows residual flow in the LAA, irrespective of neoendothelialization, PDL were excluded from this study. Diabetes mellitus, liver disease, body-mass-index, age, device sizes and type will be assessed as predictors for incomplete NE. RESULTS: 53 consecutive patients were recruited for cCTA imaging. 36 (68%) showed no PDL and were included in the study (median age 77 years, 19% female). At median follow-up of 6 months (median 180 days, IQR 178-180), 44% of patients showed complete NE compared to 56% with NE still incomplete. Age, BMI, device type and size as well as prevalence of diabetes mellitus and liver disease did not show significant correlation with the completeness of NE. CONCLUSION: This pilot study showed that neo-endothelialization is still incomplete in a majority of patients at mid-term follow-up of 6 months after successful LAAC therapy. Further investigation on the consequences of incomplete endothelialization is needed to guide antiplatelet therapy schedules.

Assessment of peri-device leaks after interventional left atrial appendage closure using standardized imaging by cardiac computed tomography angiography.

Cardiac computed tomography angiography (cCTA) has recently been proposed for evaluation of successful interventional left atrial appendage closure (LAA/LAAC). This prospective longitudinal observational study aims to assess this proposal by applying a standardized imaging protocol to detect and quantify peri-device leaks (PDL) after LAAC. cCTA datasets of consecutive patients 6 months after successful LAAC were acquired on a third generation dual-source computed tomography system and reconstructed with a slice thickness of 0.5 mm. The standardized multi-planar reconstruction LAA occluder view for post-implantation evaluation (LOVE) algorithm was used to assess PDL in relation to LAA morphology and implanted LAAC devices. A total of 49 patients (median age 80 years, 24% female) were included consecutively. Overall PDL rate was 31%. Leak rates among different left atrial appendage morphologies varied largely. Windsock type had the highest incidence of PDL (47%). AMPLATZER™ AMULET™ device type revealed slightly higher PDL rates than WATCHMAN™ type and showed larger leaks. However, no statistical differences were found. PDL can be sized best in LOVE sagittal views, whereas a synopsis of LOVE sagittal, axial and coronal views allows further examination and detection of small leaks. PDL are common after successful interventional LAAC, which can be accurately detected and sized by standardized cCTA imaging protocols.

Relation of left atrial appendage closure devices to topographic neighboring structures using standardized imaging by cardiac computed tomography angiography.

BACKGROUND: Although left atrial appendage (LAA) anatomy and topographic relations are well understood, little is known about the impairment of neighboring structures (NBS) by an implanted left atrial appendage closure (LAAC) device. This prospective longitudinal observational study for the first time describes distances of implanted LAA closure (LAAC) devices to NBS using a standardized imaging protocol of cardiac computed tomography angiography (cCTA). HYPOTHESIS: cCTA imaging is an eligible tool for post-implantation evaluation of LAAC devices and their relation to neighboring structures. METHODS: cCTA data sets of consecutive patients 6 months after successful LAAC were acquired on a third generation dual-source CT system and reconstructed with a slice thickness of 0.5 mm. The standardized multi-planar reconstruction LAA occluder view for post-implantation evaluation (LOVE) algorithm was used to measure the distances to NBS in relation to LAA morphology and implanted LAAC devices. RESULTS: A total of 48 patients (median age 80 years, 25% female) were included. Left upper pulmonary vein and circumflex artery were generally closest to occlusion devices (median 2.9 and 2.8 mm, respectively). AMPLATZER AMULET devices were closer to the mitral valve annulus than WATCHMAN devices (6.6 mm (inter quartile range [IQR] 4.9-8.6) vs 10.9 mm (IQR 7.4-14.0), P = 0.001). Distances to the left upper pulmonary vein were affected by LAA morphology, with cauliflower type having the closest proximity (1.7 mm [IQR 1.0-3.4], P = 0.048). CONCLUSION: A standardized cCTA imaging protocol is an eligible tool to accurately measure distances to NBS. Left upper pulmonary vein and circumflex artery are closest to LAAC devices and could thus be most prone to impairment.

Interventional Left Atrial Appendage Closure Affects the Metabolism of Acylcarnitines.

BACKGROUND: Left atrial appendage closure (LAAC) represents the interventional alternative to oral anticoagulation for stroke prevention in atrial fibrillation (AF). The metabolism of acylcarnitines was shown to affect cardiovascular diseases. This study evaluates the influence of successful LAAC on the metabolism of acylcarnitines. METHODS: Patients undergoing successful LAAC were enrolled prospectively. Peripheral blood samples for metabolomics measurements were collected immediately before (i.e., index) and six months after LAAC (i.e., mid-term). A targeted metabolomics analysis based on electrospray ionization-liquid chromatography-mass spectrometry (ESI-LC-MS/MS) and MS/MS measurements was performed. RESULTS: 44 patients with non-valvular AF (median CHA2DS2-VASc score 4, median HAS-BLED score 4) and successful LAAC were included. Significant changes in acylcarnitine levels were found in the total cohort, which were mainly attributed to patients with impaired left ventricular and renal function, elevated amino-terminal pro-brain natriuretic peptide (NT-proBNP) and diabetes mellitus. Adjusted multivariable regression models revealed significant changes of five metabolites over mid-term follow-up: C2, C14:1, C16, and C18:1 decreased significantly (each p < 0.05); short-chain C5 acylcarnitine plasma levels increased significantly (p < 0.05). CONCLUSION: This study demonstrates that successful LAAC affects the metabolism of acylcarnitines at mid-term follow-up. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02985463.

Impact of left atrial appendage morphology on thrombus formation after successful left atrial appendage occlusion: Assessment with cardiac-computed-tomography.

A standardized imaging algorithm by cardiac computed tomography angiography (cCTA) (LOVE-view) was used in 30 patients to evaluate the influence of different left atrial appendage (LAA) morphologies on development of thrombosis in the LAA 6 months after implantation of an occlusion device (Watchman or Amplatzer-Cardiac-Plug) in patients with non-valvular atrial fibrillation, CHA2DS2-VASc-Score >1 and a contraindication for oral anticoagulation. The distribution of different LAA morphologies was 40% windsock, 17% broccoli and 43% chicken wing type. There was no significant difference in the level of thrombosis regarding LAA morphology or the type of chosen occlusion device. The rates of complete LAA thrombosis was 40% in broccoli type, 33% in windsock and 15% in chicken wing type. Independently of LAA type, 13% had none and 60% incomplete thrombosis. The ratio of density (LA/LAA) was 0.14 in patients with complete thrombosis and 0.67 in those with none or incomplete thrombosis. cCTA and the LOVE-view-imaging-algorithm were shown to be a valuable method for standardized imaging in clinical routine in a greater set of patients. Surprisingly thrombosis of the occluded LAA was still in progress in most cases at 6 months, whereas further studies are needed defining its clinical consequences, especially for the selection of the optimal post-procedural antithrombotic treatment strategy.

Percutaneous Closure of Left Atrial Appendage affects Mid-Term Release of MR-proANP.

The left atrial appendage (LAA) represents both a predisposing source of thrombus formation and of neuro-humoral haemostasis. This study aims to evaluate changes of biomarker expression before and after successful percutaneous closure of the LAA. Patients with atrial fibrillation and contraindication for oral anticoagulant therapy were enrolled. Blood samples were taken within 24 hours before (T1) and at least 6 months (mid-term) (T2) after successful implantation of LAA occlusion devices. Blood levels of high sensitivity troponin I and T (hsTnI, hsTnT), aminoterminal pro-brain natriuretic peptide (NT-proBNP) and mid-regional pro-atrial natriuretic peptide (MR-proANP) were evaluated at both time points. A total of 42 patients with successful percutaneous LAA closure were included. Median mid-term follow-up was of 183 days. HsTnT, hsTnI and NT-proBNP did not show any significant differences over time. Serum levels of MR-proANP increased significantly between immediate pre-intervention (T1: median = 245.7 pmol/l, IQR 155.8-361.3 pmol/l) and at mid-term follow-up (T2: median = 254 pmol/l, IQR 183.4-396.4 pmol/l) (p = 0.037). These results indicate, that percutaneous LAA closure affects neuro-humoral haemostasis by increasing MR-proANP serum levels at mid-term follow-up.

Procedural success and intra-hospital outcome related to left atrial appendage morphology in patients that receive an interventional left atrial appendage closure.

BACKGROUND: The interventional left atrial appendage (LAA) closure represents an emerging alternative to oral anticoagulation for stroke prevention in certain atrial fibrillation patients. Preliminary results have suggested high procedural success rates and fewer peri-interventional complications; however, there persists an insufficient understanding of the role of many underlying confounding variables (e.g., anatomical characteristics). HYPOTHESIS: It was investigated whether varying LAA morphologies influence procedural success as well as in-hospital outcome. METHODS: Sixty-seven patients ineligible for long-term oral anticoagulation were included in this single-center, prospective, observational registry spanning from the years 2014 to 2016. Interventions were performed with the Watchman occluder (Boston Scientific, Natick, MA) or the Amplatzer Amulet (St. Jude Medical, St. Paul, MN), at the operator's discretion. Results derived from the data describing procedural success, fluoroscopy, and peri-interventional safety events were classified according to the presenting LAA morphology (cauliflower, cactus, windsock, and chicken wing). RESULTS: Rates of successful implantation were high across all groups (≥98%; P = 0.326). Surrogate parameters underlining procedural complexity like median total duration (P = 0.415), median fluoroscopy time (P = 0.459), median dose area product (P = 0.698), and the median amount of contrast agent (P = 0.076) demonstrated similar results across all groups. Likewise, the periprocedural complication rate was not significantly different and was mainly restricted to minor bleeding events. CONCLUSIONS: Irrespective of the varying morphological presentation of the LAA, the procedural success rates, interventional characteristics, and safety events did not significantly differ among patients receiving an interventional LAA closure.