Abstract 60: Prognostic Performance of Diffusion-Weighted Magnetic Resonance Imaging in Comatose Patients Treated with Mild Hypothermia After Cardiac Arrest and Its Added Value in the Context of Neuron-Specific Enolase-Based Prognostication

Abstract

Objective: MRI-based prognostication of comatous resuscitated cardiac arrest patient has shown promising results. However, it was not validated in patients treated with therapeutic hypothermia and it is unknown how it might add to NSE-based prognostication. We sought to evaluate the prognostic performance of regional apparent diffusion coefficient (ADC) in comatose OHCA patients treated with mild hypothermia and its added value to NSE-based prognostication. Methods: OHCA registry was analyzed to identify OHCA patients older than fifteen who were treated with therapeutic hypothermia and underwent brain MRI between 2008 and 2011. Quantitative measurement of regional ADC was done by a radiologist blinded to clinical outcome. Results: Among 43 eligible patients, 11(18.6%) achieved good outcome (6-month CPC 1 or 2). Regional ADC of occipital cortex showed highest discriminatory power with its area under the curve of receiver- operating-characteristic (AUROC) 0.943 (95% CI, 0.872-1.000) and predicted poor outcome with a sensitivity of 90.6% and a specificity of 100%. For NSE (48-hour), its AUROC was 0.911 (95% CI, 0.801- 1.000) and it was correlated with the regional ADC significantly (Pearson’s r=-0.674, p<.001). The ADC- based prognostication could identify additional 5 (35.7%) poor outcome patients among 14 with 48- hour NSE <78.9ng/mL, a cutoff point suggested by a previous study. However, it did not provided additional prognostic information if 48-hour NSE was >78.9ng/mL. Conclusions: Regional ADC-based prognostication was accurate in OHCA patients treated with mild hypothermia. However, in the context of 48-hour NSE-based prognostication, it provided additional prognostic information only when 48-hour NSE indicated good prognosis (48-hour NSE <78.9ng/mL). Uploaded image: A scatterplot depicting the relationship between 48-hour NSE level and regional (occipital) ADC value. Vertical gray dash line: 33 ng/mL; Vertical black dash line: 78.9ng/mL