D-dimer predicts early clinical progression in ischemic stroke: confirmation using routine clinical assays.

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.