Plasma measurement of D-dimer levels for the early diagnosis of ischemic stroke subtypes

Background: Different coagulation abnormalities according to stroke subtypes have been reported. We have assessed the clinical utility of D-dimer, a product of fibrin degradation, in the early diagnosis of stroke subtypes. Methods: Patients hospitalized after an acute ischemic cerebrovascular event underwent D-dimer assay (STA Liatest D-Dimer) (reference level, <0.50 μg/mL) on days 1, 6 ± 1, and 12 ± 1 and were studied to identify stroke subtypes. Results: We included 126 patients (mean age, 75.5 years) and 63 age-matched control subjects. Stroke subtypes were cardioembolic in 34 patients (27%), atherothrombotic in 34 (27%), lacunar in 31 (25%), and unknown in 27 (21%). At all 3 measurements, D-dimer levels were significantly higher in the cardioembolic group (mean ± SEM, 2.96±0.51, 2.58±0.40, and 3.79±0.30 μg/mL, respectively) than in the atherothrombotic (1.34±0.21, 1.53±0.26, and 2.91±0.23 μg/mL, respectively) (P<.05) and lacunar (0.67±0.08, 0.72±0.15, and 0.64±0.06 μg/mL, respectively) groups (P<.01). The difference was also significant between the latter 2 groups (P<.01). We found no difference between the lacunar group and controls (0.53 ± 0.14 μg/mL). According to day 1 measurements, the optimal cutoff point for predicting cardioembolic stroke was 2.00 μg/mL, resulting in a specificity of 93.2% and in a sensitivity of 59.3%. For predicting lacunar stroke, the cutoff point was 0.54 μg/mL, with a specificity of 96.2% and a sensitivity of 61.3%. Conclusion: The increasing use of the D-dimer assay in clinical practice could be extended to patients presenting with acute cerebrovascular ischemic events to help predict stroke subtype.