RESUMEN
BACKGROUND: Evidence suggests that oxidative stress plays a principal role in myocardial damage following ischemia/reperfusion events. Recent studies have shown that the antioxidant properties of N-acetylcysteine (NAC) may have cardioprotective effects in high doses, but-to the best of our knowledge-few studies have assessed this. OBJECTIVES: Our objective was to investigate the impact of high-dose NAC on ischemia/reperfusion injury. METHODS: We conducted a randomized double-blind placebo-controlled trial in which 100 consecutive patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention (PCI) were randomly assigned to the case group (high-dose NAC 100 mg/kg bolus followed by intracoronary NAC 480 mg during PCI then intravenous NAC 10 mg/kg for 12 h) or the control group (5% dextrose). We measured differences in peak creatine kinase-myocardial band (CK-MB) concentration, highly sensitive troponin T (hs-TnT), thrombolysis in myocardial infarction (TIMI) flow, myocardial blush grade (MBG), and corrected thrombolysis in myocardial infarction frame count (cTFC). RESULTS: The peak CK-MB level was comparable between the two groups (P = 0.327), but patients receiving high-dose NAC demonstrated a significantly larger reduction in hs-TnT (P = 0.02). In total, 94% of the NAC group achieved TIMI flow grade 3 versus 80% of the control group (P = 0.03). No significant differences were observed between the two groups in terms of changes in the cTFC and MBG. CONCLUSIONS: In this study, NAC improved myocardial reperfusion markers and coronary blood flow, as revealed by differences in peak hs-TnT and TIMI flow grade 3 levels, respectively. Further studies with large samples are warranted to elucidate the role of NAC in this population. ClinicalTrials.gov identifier: NCT01741207, and the Iranian Registry of Clinical Trials (IRCT; http://irct.ir ) registration number: IRCT201301048698N8.