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 @ years of medication ( @ % vs. @ % , p = @ ) , while there was no significant difference of mild ( @ vs. @ ) , severe ( @ vs. @ ) , and fatal ( @ vs. @ ) hemorrhage incidences between the warfarin and aspirin groups ( p > @ ) .