(200 days)
The Dimension Vista® High-Sensitivity Troponin I (TNIH) assay is for in vitro diagnostic use in the quantitative measurement of cardiac troponin I in human plasma using the Dimension Vista system. The assay can be used to aid in the diagnosis of acute myocardial infarction (AMI).
The Dimension Vista® TNIH assay is a homogeneous, sandwich chemiluminescent immunoassay based on LOCI® technology. The LOCI reagents include two synthetic bead reagents and two biotinylated anti-cardiac troponin I monoclonal antibody fragments. The first bead reagent (Sensibeads) is coated with streptavidin and contains photosensitizer dye. The second bead reagent (Chemibeads) is coated with a third anticardiac troponin I monoclonal antibody and contains chemiluminescent dye. Sample is incubated with Chemibeads and biotinylated antibodies to form bead-cardiac troponin Ibiotinylated antibody sandwiches. Sensibeads are added and bind to the biotin to form bead-pair immunocomplexes. Illumination of the complex at 680 nm generates singlet oxygen from Sensibeads which diffuses into the Chemibeads, triggering a chemiluminescent reaction. The resulting signal is measured at 612 nm and is a direct function of the cardiac troponin I concentration in the sample. Lithium heparin plasma specimens may be used. The reagent is stored unopened at 2 – 8 °C, is stable sealed on system for 30 days and opened on the system for 7 days. Calibration is performed every 30 days for a reagent lot.
The provided document describes the Siemens Healthcare Diagnostics Dimension Vista High-Sensitivity Troponin I (TNIH) Assay. The following information regarding its acceptance criteria and a study proving its performance is extracted:
Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Detection Limit | ||
| - Limit of Blank (LoB) | 95th percentile of all values, measured using a non-parametric approach. | 1.0 pg/mL |
| - Limit of Detection (LoD) | Non-parametric approach following CLSI EP17-A2. | 2.0 pg/mL (consistent with range of 0.7 - 1.9 pg/mL) |
| Limit of Quantitation (LoQ) | Analyte level with a within-lab CV of ≤ 20.0%. | 3.0 pg/mL (Lot-1: 1.2 pg/mL, Lot-2: 2.4 pg/mL, Lot-3: 2.2 pg/mL) |
| 10% CV Limit | Analyte level with a within-lab CV of ≤ 10.0%. | Consistent with 10.0 pg/mL (Lot-1: 2.7 pg/mL, Lot-2: 5.7 pg/mL, Lot-3: 5.4 pg/mL) |
| Precision | All precision goals were met. (Specific goals for SD and %CV not explicitly detailed but implied by "All precision goals were met" statement). | Repeatability: Plasma 1 (48.9 pg/mL): 1.12 SD, 2.3% CV; Plasma 2 (157.7 pg/mL): 1.55 SD, 1.0% CV; QC (8088.5 pg/mL): 99.54 SD, 1.2% CV. |
| Within-Lab: Plasma 1: 3.05 SD, 6.2% CV; Plasma 2: 2.60 SD, 1.6% CV; QC: 200.36 SD, 2.5% CV. | ||
| Linearity | The p values of nonlinear terms in the quadratic and cubic fit equations are non-significant (p ≤ 0.05). If p-value > 0.05, then allowable bias is ≤ 10% or 3 pg/mL, whichever is greater. | Confirmed linearity from 3.0 - 25,000.0 pg/mL. |
| Interferences | Bias exceeding 10% is considered interference. | Exogenous Compounds: No interference detected from Hemoglobin (400 mg/dL), Bilirubin (conjugated 30 mg/dL, unconjugated 40 mg/dL), Lipemia (3000 mg/dL) at approximately 40 pg/mL and 1350 pg/mL cTnI. |
| Numerous therapeutic/toxic substances: No interference detected at specified low/therapeutic and high/toxic concentrations (details in document for each substance). | ||
| High Dose Hook Effect | Not explicitly stated as a numerical criterion, but implies absence of hook effect. | No hook effect found at 1,000,000 pg/mL troponin. |
| Dilution Recovery | Supported use of diluent for over-range samples. (Specific numerical criteria not explicitly stated). | Testing supported use of the diluent for over-range samples. |
| Calibration Stability | P-value of regression slope ≥ 0.05 OR drift ≤ LoQ OR drift ≤ 10% for values up to 20,000 pg/mL OR drift ≤ 13% for values > 20,000 pg/mL. | Calibration interval measured to be 30 days. |
| Open Well Stability | P-value of regression slope ≥ 0.05 OR drift ≤ LoQ OR drift ≤ 10% for values up to 20,000 pg/mL OR drift ≤ 13% for values > 20,000 pg/mL. | Stability of reagents opened onboard the instrument was 7 days per well set. |
| Sample Stability | Lower bound of the one-sided 95% confidence interval of the regression line must be ≤ -10% AND all individual data points must have a bias of ≤ -20% when compared to time zero. | Separated samples stable for 8 hours at room temperature, 24 hours at 2-8 °C, up to 40 days at or below -20 °C (non-frost free), and up to 1 year at or below -70 °C. |
| Clinical Performance (Sensitivity) | Not explicitly stated as acceptance criteria, but clinical performance is assessed for diagnostic accuracy. | Pooled Gender (58.9 pg/mL 99th percentile): ranged from 79.0% (0-24h). |
| Male (78.5 pg/mL 99th percentile): ranged from 74.0% (0-24h) to 92.5% (0-24h) to 94.4% (0- |
§ 862.1215 Creatine phosphokinase/creatine kinase or isoenzymes test system.
(a)
Identification. A creatine phosphokinase/creatine kinase or isoenzymes test system is a device intended to measure the activity of the enzyme creatine phosphokinase or its isoenzymes (a group of enzymes with similar biological activity) in plasma and serum. Measurements of creatine phosphokinase and its isoenzymes are used in the diagnosis and treatment of myocardial infarction and muscle diseases such as progressive, Duchenne-type muscular dystrophy.(b)
Classification. Class II.