i-STAT hs-TnI cartridge with the i-STAT 1 System

The i-STAT hs-TnI cartridge with the i-STAT 1 System is an in vitro diagnostic test that measures cardiac troponin I (cTnI) in whole blood or plasma samples in point-of-care and clinical laboratory settings. The test is intended to aid in the diagnosis of myocardial infarction (MI) and provides quantitative results in approximately 15 minutes.

The candidate device uses an enzyme-linked immunosorbent assay (ELISA) with electrochemical detection, whereas the predicate uses chemiluminescent detection. Both employ single-use cartridges with capture antibodies on para-magnetic microparticles. The candidate requires no user calibration (pre-set during manufacturing), while the predicate requires user calibration every four weeks. Sample volume is smaller (~22 µL vs. 100 µL), reportable range is narrower (2.9–1000.0 ng/L vs. 4.1–50,000 ng/L), and time to result is comparable (~15 minutes vs. within 17 minutes).

CLSI EP05-A3 (Precision), CLSI EP06-Ed2 (Linearity), CLSI EP07-ED3 (Interference), CLSI EP09c (Procedure Comparison and Bias), CLSI EP15-A3 (User Verification of Precision), CLSI EP17-A2 (Detection Capability), and CLSI EP35 (Specimen Type Equivalence).

Both devices measure the same analyte (cTnI), are classified identically (Class II, product code MMI), share the same intended use and settings, and employ fundamentally equivalent immunoassay sandwich formats. Despite differences in detection technology (electrochemical vs. chemiluminescent) and calibration approach, extensive analytical and clinical performance data demonstrate comparable precision, linearity, reference ranges, and diagnostic accuracy (sensitivity and specificity). The clinical pivotal study of 3,585 ED patients showed clinical sensitivity and specificity meeting or exceeding those of the predicate across multiple time points and using both overall and sex-specific 99th percentile cutoffs. Matrix equivalence studies confirmed performance across multiple specimen types. These data establish that functional performance is equivalent despite technological differences.