Practical guide on left atrial appendage closure for the non-implanting physician: an international consensus paper.
Tatjana Potpara, Marek Grygier, Karl Georg Häusler...
https://pubmed.ncbi.nlm.nih.gov/38291925Actively Recruiting
Age: 18Years +
All Genders
ID07575867
CLOT-LESS - CLOsure Tailored: LEss Antithrombotic Strategy After LAAC for Stroke Prevention
Led by National Medical Research Center for Therapy and Preventive Medicine · Updated on 2026-05-08
464
Participants Needed
1
Research Sites
N/A
Total Duration
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AI-Summary
What this Trial Is About
Researchers are evaluating whether a less intense antithrombotic treatment after left atrial appendage closure (LAAC) is better than long-term standard-dose oral anticoagulants for patients with non-valvular atrial fibrillation (NVAF). This observational study aims to shed light on the best post-procedure therapy, as current guidelines lack consensus on optimal treatment. The study is conducted at the National Medical Research Center for Therapy and Preventive Medicine and involves patients at risk of stroke due to NVAF. Participants will either undergo LAAC using Watchman FLX or Amplatzer Amulet devices followed by reduced-dose apixaban (2.5 mg twice daily) for three months and then stop all antithrombotic therapy if imaging confirms successful closure without leaks or device-related clots. Alternatively, participants will receive standard full-dose direct oral anticoagulants (DOACs) like apixaban or rivaroxaban for the entire study duration. Follow-up includes imaging at 3, 6, and 12 months for the LAAC group and regular phone check-ins for both groups up to 36 months. Participants will be monitored through imaging tests such as transesophageal echocardiography or cardiac CT scans to evaluate device sealing and detect possible complications. Telephone follow-ups will continue every 6 months up to 36 months after enrollment. The main outcomes measured include major bleeding, death, ischemic stroke, systemic embolism, device-related thrombosis, and peri-device leaks. The study aims to compare safety and effectiveness outcomes between the reduced-dose apixaban after LAAC and long-term standard-dose DOAC therapy over three years.
CONDITIONS
Brief Title
CLOT-LESS - CLOsure Tailored: LEss Antithrombotic Strategy After LAAC for Stroke Prevention
Who Can Participate
Age: 18Years +
All Genders
Eligibility Criteria
You may qualify if you...
- Age 18 years or older
- Documented nonvalvular atrial fibrillation confirmed by ECG within the past 12 months
- CHA2DS2-VASc score of 3 or higher for women and 2 or higher for men
- Signed informed consent to participate in the study
You will not qualify if you...
- Need for anticoagulation treatment other than for atrial fibrillation during the study period
- Unable to tolerate at least 3 months of apixaban therapy (for LAAC group)
- Need for antiplatelet or P2Y12 inhibitor therapy at inclusion or during the study
- Presence of mechanical heart valves or moderate to severe mitral stenosis
- Active deep vein thrombosis requiring anticoagulation
- Blood clotting disorders or rheumatic heart disease
- Left ventricular ejection fraction less than 30%
- Severe kidney disease (GFR < 30 ml/min) or dialysis
- Severe liver failure, including cirrhosis and advanced liver disease
- Severe congestive heart failure (NYHA class IV)
- Recent myocardial infarction within 30 days before LAAC
- Stroke within 30 days before LAAC
- Intracardiac thrombus before LAAC
- Major bleeding within 30 days before LAAC or randomization
- Amyloid cardiomyopathy
- Platelet count below 100,000 x 10^9/l
- Participation in another interventional study
- Pregnant, breastfeeding, or planning pregnancy during the study
- Unsuccessful or interrupted LAAC procedure
- Peri-device leak of 3 mm or more
- Allergic or other contraindications to study treatments
- Planned surgery within 30 days before or 90 days after LAAC (minor procedures allowed)
- Heart tumor, active infection, or tamponade signs
- Life expectancy less than 12 months
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
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Your Study Journey
Screening
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Implementation
Duration - 1 day
Participants in the LAAC group undergo percutaneous left atrial appendage closure using Watchman FLX or Amplatzer Amulet devices.
1 procedure visit
Treatment
Duration - 3 months for LAAC group; up to 36 months for control group
Participants in the LAAC group receive reduced-dose apixaban (2.5 mg twice daily) for 3 months following device implantation. Participants in the control group receive standard-dose direct oral anticoagulant therapy for the duration of the follow-up.
Follow-up visits with transesophageal echocardiography or cardiac CT at 3, 6, and 12 months for LAAC group; telephone follow-up at 3, 6, 12, 18, 24, 30, and 36 months for both groups
Long-term Monitoring
Duration - Up to 36 months
Participants are followed up by telephone to monitor health outcomes and any adverse events for up to 36 months after enrollment.
Telephone follow-up at 18, 24, 30, and 36 months after enrollment
Trial Site Locations
Total: 1 location
1
Federal State Budgetary Institution National Medical Research Center for Therapy and Preventive Medicine of the Ministry of Healthсare of the Russian Federation
Moscow, Russia, 101990
Actively Recruiting
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Research Team
T
Timofey Brontveyn, Medical doctor
K
Karapet Davtyan, Professor
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
2
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Published Research Related To This Trial
Single versus dual antiplatelet therapy following percutaneous left atrial appendage closure-A systematic review and meta-analysis.
Saverio Continisio, Carolina Montonati, Filippo Angelini...
https://pubmed.ncbi.nlm.nih.gov/38597271Single antiplatelet therapy following Amplatzer left atrial appendage occlusion.
Anders Kramer, Kasper Korsholm, Jens Erik Nielsen-Kudsk
https://pubmed.ncbi.nlm.nih.gov/38436367Clinical Effectiveness and Safety Comparison between Reduced Rivaroxaban Dose and Dual Antiplatelet Therapy for Nonvalvular Atrial Fibrillation Patients Following Percutaneous Left Atrial Appendage Closure: A Prospective Observational Study.
Xiaoye Li, Qinchun Jin, Yao Yao...
https://pubmed.ncbi.nlm.nih.gov/39076450Low Dose of Direct Oral Anticoagulants after Left Atrial Appendage Occlusion.
Pedro Luis Cepas-Guillen, Eduardo Flores-Umanzor, Ander Regueiro...
https://pubmed.ncbi.nlm.nih.gov/34821695Short-term direct oral anticoagulation or dual antiplatelet therapy following left atrial appendage closure in patients with relative contraindications to chronic anticoagulation therapy.
Laurent Faroux, Ignacio Cruz-González, Dabit Arzamendi...
https://pubmed.ncbi.nlm.nih.gov/33647365Safety and efficacy of early anticoagulation drug regimens after WATCHMAN left atrial appendage closure: three-month data from the EWOLUTION prospective, multicentre, monitored international WATCHMAN LAA closure registry.
Martin W Bergmann, Timothy R Betts, Horst Sievert...
https://pubmed.ncbi.nlm.nih.gov/28606886Low-Dose Direct Oral Anticoagulation vs Dual Antiplatelet Therapy After Left Atrial Appendage Occlusion: The ADALA Randomized Clinical Trial.
Xavier Freixa, Ignacio Cruz-González, Pedro Cepas-Guillén...
https://pubmed.ncbi.nlm.nih.gov/39110427Looking for optimal antithrombotic strategy after transcatheter left atrial appendage occlusion: a real-world comparison of different antiplatelet regimens.
Luigi Vignali, Filippo Luca Gurgoglione, Federico Barocelli...
https://pubmed.ncbi.nlm.nih.gov/36181948Short-term antiplatelet versus anticoagulant therapy after left atrial appendage closure: a systematic review and meta-analysis.
Qiang Zhou, Xiang Liu, Zhi-Chun Gu...
https://pubmed.ncbi.nlm.nih.gov/38180590