RESUMO
BACKGROUND: Oxidative stress is a pathological feature of acute coronary syndrome (ACS), a complex disease with varying clinical outcomes. Surrogate biomarkers of oxidative stress including, peroxiredoxin-2 (PRDX2), PRDX4, thioredoxin (TRX) and thioredoxin reductase (TRXR) were measured in ACS patients at presentation and follow-up, to assess their clinical utility in diagnosis and risk stratification. METHODS: Plasma from 145 participants (80 ACS and 65 healthy) at diagnosis, 1-3 month (first) and 6-month follow-up (second) was analysed by ELISA. ACS patients were monitored for 12-months. RESULTS: ACS patients at diagnosis had significantly higher concentrations of TRX (p < 0.05), TRXR (p < 0.01) and PRDX4 (p < 0.01), compared to healthy donors. This was increase was driven by non-ST elevated myocardial infarction for TRX (p < 0.01) and PRDX4 (p < 0.05). For TRXR, ACS females were significantly higher than males (p < 0.05). TRX was also higher in older females (>55 years) at diagnosis (p < 0.05). At first follow-up, TRX had lowered, whereas PRDX4 remained significantly high (p < 0.05). Stratification of ACS patients according to percutaneous coronary intervention (PCI) revealed that TRXR was significantly higher in patients receiving PCI to the right coronary artery (p < 0.05). Whereas both TRXR (p < 0.01) and PRDX4 (p < 0.01) were significantly higher in patients receiving PCI to the left anterior descending (LAD) artery. ACS patients who had plasma TRX >13.40 ng/ml at second follow-up were at high risk of readmission (p < 0.05), as were patients with TRXR of <1000 pg/ml at diagnosis having PCI to the LAD (p < 0.05). CONCLUSION: This study indicates that TRX, TRXR and PRDX4 may have clinical utility for ACS stratification.