Binary outcomes (thromboembolic or bleeding events) will be analysed by Mcnemar test at a 5% level of significance using intention to treat i.e. considering missing data as adverse outcomes. In this case sensibility analysis will be conducted [update: we decided for just presenting the events recorded during the trial without any hypothesis testing due to cross-over design limitations and lower power for these outcomes]. Exploratory analysis for subgroup of patients are not intended.