exploratory observation of two short-term regimens after laa occlusion by lamax laac® device for subjects with non-valvular atrial fibrillation

Conditions: Non-valvular Atrial Fibrillation

Summary: this is a prospective, single-center, randomized, exploratory clinical observation to explore the overall benefit of short-term dual antiplatelet or novel oral anticoagulant regimens after left atrial appendage (laa) occlusion by lamax laac® occluder for subjects with non-valvular atrial fibrillation (af), which will provide a basis for subsequent research on real-world safety and efficacy of laa closure (laac).

anticoagulation is necessary after transcatheter left atrial appendage closure (laac) and is important to prevent thrombosis and device-related thrombosis (drt). bleeding events and stroke should be reduced while reducing thrombosis. based on the characteristics of the lamax laac® device, experts recommend studying short-term medication regimens for patients with non-valvular atrial fibrillation after laac. this trial is a prospective, single-center, randomized, open-label and parallel design. it is estimated that 54 patients will take part in the study. subjects with non-valvular atrial fibrillation undergo transcatheter laac using the lamax laac® device, and then are randomly enrolled in observation group 1/observation group 2 of the medication regimen in a 1:1 ratio after laac. observation group 1 (dual antiplatelet group, 27 subjects): 4 weeks post-laac (aspirin 100 mg + clopidogrel 75 mg); 4-24 weeks post-laac (aspirin/clopidogrel); recommended long-term aspirin treatment after 24 weeks (clopidogrel can be used instead if aspirin is intolerant). observation group 2 (novel oral anticoagulant group, 27 subjects): 4 weeks post-laac (conventional dose noac); 4-24 weeks post-laac (aspirin/clopidogrel); recommended long-term aspirin treatment after 24 weeks (clopidogrel can be used instead if aspirin is intolerant).

Eligibility criteria:
inclusion criteria: * 1. patients ≥ 18 years old with non-valvular atrial fibrillation (af); * 2. subjects with laac indications: according to the 2023 scai/hrs expert consensus statement on transcatheter left atrial attachment closure, transcatheter laac is suitable for non-valvular af patients with high risk of thromboembolism but unsuitable for long-term use of oral anticoagulants (oacs), including the following situations: 1. have a much higher risk of having stroke (cha2ds2-vasc score: male ≥ 2 points, female ≥ 3 points), 2. have oac intolerance or a much higher risk of bleeding (such as has-bled score ≥ 3 points), 3. have sufficient life expectancy (minimum\>1 year) and expected to improve quality of life after laac; * 3. successful left atrial appendage occlusion with lamax laac® device; * 4. patients and their families fully understand the purpose of the study, voluntarily participate in the study and sign the informed consent form. exclusion criteria: * 1. combined with other diseases except af requiring long-term warfarin or other anticoagulant therapy; * 2. absolute contraindications for anticoagulation therapy or unacceptable bleeding risk with dual antiplatelet therapy; * 3. indications to dual antiplatelet therapy other than atrial fibrillation and/or left atrial appendage occlusion at the time of enrollment or predicted appearance of such indications within the duration of the trial (e.g. planned coronary revascularization); * 4. occluder dislocation, pericardial effusion (including new pericardial effusion and significantly increased pre-existing pericardial effusion) and other bleeding complications within 24 hours after laac; * 5. patients scheduled for catheter ablation after left atrial appendage electrical isolation and during the study; * 6. patients resistant to clopidogrel; * 7. patients requiring elective cardiac surgery; * 8. heart failure nyha grade iv and not been corrected yet; * 9. patients with af caused by rheumatic valvular heart disease, degenerative valvular heart disease, congenital valvular heart disease, severe mitral stenosis, aortic stenosis and other valvular diseases; * 10. initial atrial fibrillation, paroxysmal atrial fibrillation with a clear cause such as coronary artery bypass grafting (cabg) \< 12 months, hyperthyroidism, etc. * 11. patients with acute myocardial infarction or unstable angina pectoris, or recent myocardial infarction \< 12 months; * 12. patients with active bleeding, bleeding constitution or bleeding disorders, coagulation history and unhealed gastrointestinal ulcer; * 13. infective endocarditis, vegetation or other infections causing bacteremia, sepsis; * 14. female patients who are pregnant, lactating, or planning to become pregnant during this study; * 15. patients who have participated in other drug or device clinical trials and have not reached the endpoint; * 16. patients with renal insufficiency (endogenous creatinine clearance \< 30ml/min) (using the standard crockcroft-gault formula) and/or advanced renal disease requiring dialysis; * 17. severe hepatic dysfunction (ast/alt greater than 5 times the upper limit of normal or total bilirubin greater than 2 times the upper limit of normal); * 18. patients considered unsuitable for this study by the investigator. * 19. left atrial appendage has been removed, post heart transplantation, post atrial septal repair, or post occluder implantation; * 20. post prosthetic heart valve replacement; * 21. allergic to or contraindication to metal nickel alloy, aspirin, clopidogrel, contrast agent, heparin and other anticoagulants, etc; * 22. patients who have placed other instruments in the cardiovascular cavity and are unable to place the laa occluder; * 23. lvef（left ventricular ejection fraction, by simpson method）\<35%； * 24. clear thrombus is found in the heart before laac; * 25. tee examination: the maximal orifice diameter of laa is less than 12 mm, or more than 36 mm; * 26. residual flow after laac \>5mm； * 27. patent foramen ovale with high risk; * 28. mitral stenosis with a valve area \<1.5cm2; * 29. left atrial diameter (antero-posterior diameter) \> 65mm, or pericardial effusion more than a small amount, the depth of local effusion \> 10 mm; * 30. contraindications to x-ray, or not suitable for tee examination.

Keywords: atrial fibrillation left atrial appendage closure ischemic stroke device-related thrombosis