Study of Reduced-Dose Apixaban After Left Atrial Appendage Closure Compared to Standard Anticoagulant Therapy in Patients with Non-Valvular Atrial Fibrillation for Stroke Prevention

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.

CLOT-LESS - CLOsure Tailored: LEss Antithrombotic Strategy After LAAC for Stroke Prevention