Infarct Volume Predictive of Functional Outcome After Acute Ischemic Stroke
There were no differences in strength between assessment of follow-up infarct volume and functional outcome at ≤48 hours or >48 hours.
Follow-up infarct volume (FIV) is a reliable predictor of functional outcome approximately 90 days after an acute ischemic stroke caused by a proximal intracranial occlusion, according to a meta-analysis published in the Journal of Neurointerventional Surgery.
In this pooled analysis of seven randomized-controlled trials, investigators examined the association of FIV with functional outcome following an acute ischemic stroke. A total of 1665 patients were included in the analysis, of whom 83% were imaged with computed tomography (CT) for FIV (median FIV, 41 mL [interquartile range] 14-120).
The degree of disability as assessed by the 90-day modified Rankin Scale (mRS) score comprised the primary outcome. Adjusted and unadjusted ordinal or binary logistic regression models were used to estimate the association between FIV and ordinal mRS score.
Patients with acute ischemic stroke with a large FIV were more likely to have worse functional outcomes in the adjusted analysis (odds ratio [OR] 0.88; 95% CI, 0.87-0.89 per 10 mL). The superior model (ie, model D) for predicting unfavorable outcomes in these patients included variables such as FIV, location of infarct, and hemorrhage type (OR 0.92; 95% CI, 0.90-0.94). An infarct volume of ≥133 mL represented a highly specific (95% specificity) threshold for predicting unfavorable outcome (95% CI, 92.3-97.1).
There were no differences in strength between assessment of FIV and functional outcome at ≤48 hours (Spearman ρ = 0.60; 95% CI, 0.56-0.64; P <.0001) or >48 hours (Spearman ρ = 0.55; 95% CI, 0.50-0.60; P <.0001). Although significantly lower FIVs were found in patients imaged with MRI (median, 22 mL) compared with CT (median, 48 mL) (P <.001), model D showed no significant difference between imaging modalities in terms of mRS score (P =.28).
Variations in reperfusion rates as well as MRI assessments among included studies represent possible limitations of this meta-analysis.
Findings from this study indicate “FIV might be suitable as a prognostic biomarker for functional outcome in acute ischemic stroke, irrespective of imaging modality and time to follow-up imaging.”
Boers AMM, Jansen IGH, Beenen LFM, et al. Association of follow-up infarct volume with functional outcome in acute ischemic stroke: a pooled analysis of seven randomized trials [published online April 7, 2018]. J Neurointerv Surg. doi:10.1136/neurintsurg-2017-013724