*Statistical Analysis*

The SPSS 20.0 and GraphPad Prism 7.0 software were used to perform statistical analysis. Descriptive statistics were used to outline patients' characteristics. Results are expressed as mean ± SD or *n* (%). Incidence rate was calculated as number of bleeding events per 100 patients per year. For parametric variables, we compared means using paired samples Student's t test. P values less than 0.05 were considered statistically significant.
