RESUMO
OBJECTIVE: To observe and assess the effect of different dosages of aspirin on inflammatory biomarkers, hemorheology (platelet aggregation rate) and clinical prognosis in patients with acute coronary syndrome (ACS). METHODS: ACS patients were randomly assigned to receive different dosages of aspirin treatment orally. Patients in group A, B and C took 100 mg, 500 mg and 1000 mg of aspirin per day respectively. They were treated and followed-up for 1 year. High-sensitivity C-reactive protein (hsCRP), IL-6, tumor necrosis TNFalpha and platelet aggregation rate were examined and major adverse cardiac events (MACE) were recorded. RESULTS: A total of 312 patients with ACS were enrolled in the study. The baseline characteristics of the three groups were not different with respect to age, gender, cardiovascular risk profile, level of inflammatory biomarkers and concomitant treatment before and after randomization. The levels of baseline serum hsCRP, IL-6 and TNFalpha were higher in subjects of the study as compared with normal reference value (P < 0.05, < 0.05, < 0.01) and they decreased significantly after therapy with 3 different doses of aspirin (detected at 30 days, 6 months and 12 months, P < 0.001), but there were no significant differences among the three groups (P > 0.05). Rehospitalization, MACE and the change of platelet aggregation ratio were not significantly different among the three groups. The incidence of gastrointestinal complaints was significantly higher in groups B and C than in group A (P < 0.05). CONCLUSIONS: The levels of serum inflammatory biomarker increase in patients with ACS. Aspirin therapy may decrease the level of inflammatory markers significantly, but increasing the dosage of aspirin from 100 mg to 1000 mg daily does not decrease the level of inflammatory markers and the clinical MACEs further. However, the incidence of gastrointestinal complaints increase significantly with the increase of aspirin dosage.