Impact on atrial an brain natriuretic peptide secretion after percutaneous left atrial appendage closure

The WATCHMAN LAA system (Altritech Inc., Plymouth, MN),Percutaneous occlusion systems have been developed as an alternative to anticoagulation for stroke prevention. Briefly, transseptal puncture is performed to gain access to the left atrial appendage (LAA). Thereafter LAA angiography is performed. After an optimal device size is chosen based on LAA measurements by fluoro and echocardiography the occluder is implanted into the orifice of the left atrial appendage under fluoroscopy and TEE-guidance. The size of the device is chosen to be 10% to 20% larger than diameter of the LAA ostium to have stable positioning of the device. Every procedure is performed under local anaesthesia. Heparin is given during implantation procedure to achieve an activated clotting time of at least 250.

Venous blood samples are taken before the procedure, immediately after implantation of the LAA closure device and on the first morning after the procedure. The blood is drawn into plastic tubes containing aprotinin and ethylenediaminetetraacetic acid disodium and is promptly centrifuged. The plasma obtained is stored at -20°C until assayed. The plasma BNP and ANP concentrations are then determined with a commercially available enzyme immunoassay kit (ELISA Kit for Brain Natriuretic Peptide, Uscn Life Science Inc., Missouri City, USA and ANP ELISA Kit, Hölzel Diagnostika, Köln, Germany).