Final infarct volume discriminates outcome in mild strokes.

Introduction: Knowledge of whether final infarct volume (FIV) predicts disability after mild stroke is limited. We sought to determine if FIV could differentiate good versus poor outcome after mild stroke.

Methods: We retrospectively identified 65 patients with mild stroke (National Institutes of Health Stroke Scale≤5) in a multicenter registry of 2453 patients. We evaluated associations between FIV and clinical outcome and evaluated the optimal FIV threshold that discriminated favorable (modified Rankin scale (mRS) 0-1) versus poor (mRS 2-6) outcome.

Results: The FIV cut-point of 20 mL differentiated favorable and poor outcomes (area under curve (AUC) 0.73, 95% confidence interval: 0.58-0.88). Favorable outcome was observed in 37/45 (82%) with FIV<20 mL, compared to 5/14 (36%) with FIV≥20 mL (p<0.01). FIV≥20 mL remained strongly associated with poor outcome independent of age, gender, stroke severity, Alberta Stroke Program Early CT Score (ASPECTS), and proximal arterial occlusion.

Conclusion: In our small sample size, an FIV of 20 mL best differentiated between the likelihood of good versus poor outcome in patients with mild stroke. Further validation of infarct volume as a surrogate marker in mild stroke is warranted.