Bedside Multimarker Testing for Risk Stratification in Chest Pain Units

Abstract

Background —Earlier, rapid evaluation in chest pain units may make patient care more efficient. A multimarker strategy (MMS) testing for several markers of myocardial necrosis with different time-to-positivity profiles also may offer clinical advantages. Methods and Results —We prospectively compared bedside quantitative multimarker testing versus local laboratory results (LL) in 1005 patients in 6 chest pain units. Myoglobin, creatine kinase-MB, and troponin I were measured at 0, 3, 6, 9 to 12, and 16 to 24 hours after admission. Two MMS were defined: MMS-1 (all 3 markers) and MMS-2 (creatine kinase-MB and troponin I only). The primary assessment was to relate marker status with 30-day death or infarction. More patients were positive by 24 hours with MMS than with LL (MMS-1, 23.9%; MMS-2, 18.8%; LL, 8.8%; P =0.001, all comparisons), and they became positive sooner with MMS-1 (2.5 hours, P =0.023 versus LL) versus MMS-2 (2.8 hours, P =0.026 versus LL) or LL (3.4 hours). The relation between baseline MMS status and 30-day death or infarction was stronger (MMS-1: positive, 18.8% event rate versus negative, 3.0%, P =0.001; MMS-2: 21.9% versus 3.2%, P =0.001) than that for LL (13.6% versus 5.5%, P =0.038). MMS-1 discriminated 30-day death better (positive, 2.0% versus negative, 0.0%, P =0.007) than MMS-2 (positive, 1.8% versus negative, 0.2%; P =0.055) or LL (positive, 0.0% versus negative, 0.5%; P =1.000). Conclusions —Rapid multimarker analysis identifies positive patients earlier and provides better risk stratification for mortality than a local laboratory-based, single-marker approach.