 Statistics For any randomized trial, the power and sample size calculation are critical determinants of the overall success of the trial and the interpretation of findings. The sample size calculation was based on the following assumptions: the power of the test 0.8, statistical significance border 0.05. Based on information from large previous trials with NOAC, the investigators assume that 13 of patients in the NOAC group and 10 of patients in the interventional group will achieve the primary endpoint per year. 15 With regard to the border for non-inferiority, the investigators expect 18 of patients to achieve the primary endpoint per year. This means, that for the non-inferiority hypothesis, 198 patients will have to be enrolled in each group, i.e. a total of 396 study participants. Data analysis will be performed based on intention-to-treat principles. For data description, standard descriptive statistical methods will be used: absolute and relative frequencies for categorical data and the median with 5-95 percentiles for continuous data. For categorical variables, statistical analysis will be done using the χ2 or the Fisher exact test; for continuous variables, the Student t-test or Mann-Whitney U test will be used. Kaplan-Meier curves will be calculated for visualizing the occurrence of end-points during follow-up. The influence of patient characteristics on the occurrence of end-points will be calculated using logistic regression and the Cox proportional risk model, when appropriate. Statistical analyses will be done using SPSS 22 software IBM Corporation, 2013. 