Use of biomarkers in triage of patients with suspected stroke

Background: The absence of a rapidly available and sensitive diagnostic test represents an important limitation in the triage of patients with suspected stroke. Objectives: The aim of the present study was to investigate the triage accuracy of a novel test that measures blood-borne biomarkers (triage stroke panel, TSP) and to compare its accuracy with that of the Cincinnati Prehospital Stroke Scale (CPSS). Methods: Consecutive patients with suspected stroke presenting to the Emergency Departments of three Italian hospitals underwent triage by a trained nurse according to the CPSS and had blood drawn for TSP testing. The TSP simultaneously measures four markers (B-type natriuretic peptide, D-dimer, matrix metalloproteinase-9, and S100β) presenting a single composite result, the Multimarker Index (MMX). Stroke diagnosis was established by an expert committee blinded to MMX and CPSS results. Results: There were 155 patients enrolled, 87 (56%) of whom had a final diagnosis of stroke. The area under the receiver operating characteristic (ROC) curve for CPSS was 0.77 (95% confidence interval [CI] 0.70-0.84) and that of MMX was 0.74 (95% CI 0.66-0.82) (p = 0.285). Thus, both tests, when used alone, failed to recognize approximately 25% of strokes. The area under the ROC curve of the combination of the two tests (0.86, 95% CI 0.79-0.91) was significantly greater than that of either single test (p = 0.01 vs. CPSS and p < 0.001 vs. TSP). Conclusions: In an emergency care setting, a panel test using multiple biochemical markers showed triage accuracy similar to that of CPSS. Further studies are needed before biomarkers can be introduced in the clinical work-up of patients with suspected stroke.