 The limitation of anticoagulative drugs was one of reasons behind the development of nonpharmacological treatments for AF. Because about 90 of left atrial thrombi occur in the LAA; 6 the occlusion of the LAA is the main non-pharmacological option for prevention of cardioembolic event from the LA. LAA occlusion is performed using a percutaneous approach; the catheter is inserted through the femoral vein via a transseptal puncture into the LA. The LAA is visualized and closed using a special device. Currently, two different devices are present on the market Watchman, Boston Scientific and Amplatzer Cardiac Plug, St. Jude Medical. The largest trial published regarding LAA occlusion was the PROTECT trial. 14 In this prospective randomized multicenter trial, occlusion of the LAA using a Watchman device was compared with standard warfarin treatment. The LAA occlusion was non-inferior to warfarin; the incidence of cardioembolic events and death was similar in both groups 3 of patients per year in the LAA occlusion group vs. 4.9 of patients per year in the warfarin group. The major disadvantage of LAA occlusion was related to peri-procedural and device-related complications, which were present in 7.4 of patients per year. Fifty-five percent of the reported adverse event occurred on the day of the procedure and the most often was significant pericardial effusion, which was present in 4.8 patients. In summary, LAA occlusion can be associated with significant risk of peri-procedural complications; additionally, while it is reduced, the risk of thrombus formation in the LA is not eliminated. In other study assessing LAA occlusion, periprocedural and device-related complications occurred in 6 - 8. 15 Despite the risk, LAA occlusion presents a very promising alternative to anticoagulant treatment for patients with a very high risk of bleeding, or in those contraindicated for warfarin or NOAC. For patients with the highest CHA2DS2-VASc and HAS-BLED scores, no studies have been published to date, and no studies are in progress according to the randomized trial study registry. The inclusion criterion in the PROTECT study was a CHADS2 score 1, with approximately 13 of patients having a CHADS2 of 1 only. 14 The anticoagulation treatment is well established in the majority of patients with AF in standard clinical practice; however, despite the anticoagulation treatment, systemic cardioembolic event can occur and bleeding risks can be very serious. In the largest study with rivaroxaban, the ROCKET study, in which the drug was compared to warfarin, the annual incidence of stroke was in 1.7 - 2.2 of patients and the annual incidence of any bleeding both major and minor was 15 11 Similarly, in the ARISTOTLE study, in which another NOAC apixaban was compared to warfarin, the annual incidence of cardioembolic event was 1.27 - 1.6, and the annual risk of major or clinically significant bleeding was 4 - 6.10 The best treatment for those AF patients at highest risk, i.e. 