The warfarin medication was superior regarding the overall occurrence of ischemic stroke or systemic embolism as well as non-fatal myocardial infarction and all causes of death outcomes compared to aspirin administration during the 2 years of medication ( 17.6 % vs. 36.0 % , p = 0.03 ) , while there was no significant difference of mild ( 5 vs. 4 ) , severe ( 2 vs. 1 ) , and fatal ( 1 vs. 1 ) hemorrhage incidences between the warfarin and aspirin groups ( p > 0.05 ) .