AspirinPlatelet Aggregation InhibitorsAnti-Inflammatory Agents, Non-SteroidalTiclopidineDrug Administration ScheduleThromboxane B2Double-Blind MethodCyclooxygenase InhibitorsDrug Therapy, CombinationDose-Response Relationship, DrugPlatelet AggregationAdministration, OralSalicylatesTreatment OutcomePlatelet Function TestsTime FactorsBlood PlateletsSodium SalicylateWarfarinAnticoagulantsTablets, Enteric-CoatedFibrinolytic AgentsProspective Studies