Treatment in the two groups
| Group | Time period | Treatment |
| Indobufen | Day 1 to 90±7 | The first time*: indobufen 100 mg+aspirin placebo |
| The second time: indobufen 100 mg | ||
| Aspirin | Day 1 to 90±7 | The first time*: aspirin 100 mg+indobufen placebo |
| The second time: indobufen placebo |
*The interval between two administrations should be at least 8 hours.