Background and Purpose--Plasma D-dimer levels, measured using a research laboratory assay, independently predict progressing ischemic stroke. We wished to confirm these findings using commercially available assays and to provide data to allow the design of intervention studies.

Methods--We studied 219 consecutive acute ischemic stroke admissions of whom 54 (25%) met criteria for progressing stroke.

Results--There were strong correlations between D-dimer results as measured by the Biopool AB, MDA and VIDAS assays; correlation coefficients r=0.91 to 0.94; all P<0.001. In binary logistic regression analyses, D-dimer, as measured by the 3 different assays, was an independent predictor of progressing stroke (odds ratios, 1.87 to 2.45; all P<0.001). This confirms the results of our original analysis (Biopool AB) using 2 commercial D-dimer assays, demonstrating the potential usefulness of D-dimer in providing early prognostic information after ischemic stroke in different clinical settings. We also provide information on the performance of the 3 assays in predicting progressing stroke at a variety of cutoff values.

Conclusions--Ischemic stroke patients at high risk of early progression can be identified using commercial D-dimer measurements. This could allow selection of high-risk patients for inclusion in randomized trials of early antithrombotic treatments.