Left atrial appendage closure for thrombus trapping: the international, multicentre TRAPEUR registry

Although the presence of a thrombus contraindicates left atrial appendage closure procedure (LAAC), a previous study reported the feasibility of the thrombus trapping procedure (TTP) technique to overcome this limitation.

This study aimed to analyse the short-term outcomes in a series of patients who underwent LAAC using the TTP (TTP-LAAC).

This retrospective series included patients who underwent TTP-LAAC between January 2018 and May 2020 in 13 European centres. Device choice, pre-interventional work-up and post-discharge antithrombotic therapy regimens were left to the discretion of the operators. The primary endpoint was the 30-day occurrence of stroke, systemic embolism or cardiovascular death.

During the study period, a total of 1,918 patients underwent LAAC. A thrombus was identified in 71 cases but completely disappeared in 24 patients before procedure. TTP-LAAC was finally performed in 53 cases (3%). Thrombi were identified ahead of the actual day of implantation in 47 patients (87%) and were mostly limited in size (50 cases with extension <50% of the LAA surface). The Amplatzer Amulet and WATCHMAN FLX occluders were implanted in 44 and 9 patients, respectively. A single deployment approach was applied in 70% and a cerebral embolic protection system was used in 9% of the patients. The overall success rate was 100%. Small pericardial effusion without tamponade was observed in 6% of the cases. Patients were discharged with 72% under antiplatelet therapy and 10% under short-term oral anticoagulation. The primary endpoint occurred in one patient.

TTP-LAAC might be used in a minority of LAAC procedures but appears to be feasible and safe in the short-term, in select cases.