Abstract 17543: Molecular Correlates of Neuroimaging Findings in Acute Ischemic Stroke: Early Oxidative Stress Biomarkers of Ischemic Penumbra and Infarct Growth
Objectives: Oxidative stress (OS) is likely to play an important role in ischemic brain injury pathogenesis. Advanced neuroimaging may provide fundamental data on brain tissue viability in acute ischemic stroke (AIS). We sought to assess whether OS plasma biomarkers predict DWI-PWI mismatch and infarct growth (IG).
Methods: We prospectively measured plasma F2-isoprostane (F2-isoP), total and perchloric acid Oxygen Absorbance Capacity (ORAC-TOT and ORAC-PCA), in consecutive AIS patients presenting within 9h of symptom onset. Mismatch was defined as baseline mean transit time volume (MTTV) minus DWI volume (DWIV), and IG volume (IGV) as final infarct volume (FIV) minus baseline DWIV. A percent mismatch cut-off of 20% was used, but we also used more strict mismatch definitions adopted in clinical trials on neuroimaging in thrombolysis based on mismatch salvage and good clinical response.
Results: Mismatch >20% was found in 153/216 patients that, compared to those with ≤20% or no mismatch, were more likely to have F2-isoP (p=0.15) and ORAC-PCA (p=0.02). Compared to those without IG, 170 patients with IG have higher levels of F2-isoP (p=0.009). Baseline F2-isoP significantly correlated with IGV and FIV (Spearman’s rho=0.20,p=0.005 and 0.19,p=0.009). In a multivariate binary logistic regression model, baseline F2-isoP emerged as an independent predictor of mismatch >20% (OR 2.44 95% CI 1.19-4.98; p=0.01) and IG occurrence (OR 2.57, 95%CI 1.37-4.83; p=0.007). ORAC-TOT significantly correlated with mismatch salvage percentage (Spearman’s ρ=0.21, p=0.025). ORAC-PCA independently predict more strict mismatch definitions (>20% with PWI ≥10 mL, OR 7.94 95%CI 2.28-27.73, p=0.001; >160%, OR 4.69, 95%CI 1.59-13.85, p=0.005; >160% with PWI ≥10 mL, OR 2.82, 95%CI 1.07-7.40, p=0.036).
Discussion: Elevated hyperacute plasma F2-isoP concentrations independently predict mismatch >20%,IG,IGV in AIS patients. Higher levels of ORAC, as marker of plasma antioxidant capacity, resulted as independent predictor of mismatch salvage and more strict mismatch definitions. If validated in future studies, measuring plasma OS biomarkers might be helpful in acute routine clinical setting to stratify patients for progression and relative severity of ischemic injury.
- © 2013 by American Heart Association, Inc.