(54 days)
For the in vitro quantitative determination of troponin T in human serum and plasma.
Diagnosis of acute myocardial infarction (AMI) is generally based on the presence of at least two of three classic findings: clinical symptoms, diagnostic ECG, and serological findings of abnormal levels of total CK, LD or their isoenzymes. Often, due to the presence of clinical symptoms and changes in the ECG, the CK, CK-MB, LD and LD1 serve primarily to confirm and monitor the course of the infarction. At other times, when chest pain is atypical, or ECG changes are non-diagnostic or absent, these markers provide important diagnostic information. Limitations to these serum markers include a relatively narrow diagnostic window, difficulty in interpreting small increases and a lack of cardiac specificity. Troponin T can be an effective serum marker whose cardiac specificity and wide diagnostic window makes it a valuable tool in the diagnosis of AMI.2,4
Troponin T has been shown to be elevated in all patients with AMI who are diagnosed by World Health Organization (WHO) criteria.1 Troponin T frequently appears in serum as early as one to three hours after the onset of pain.2,5 The sensitivity of troponin T reaches 100% within hours and remains at a high sensitivity level until day five. After 48 hours the CK-MB assay is frequently of little diagnostic value.1 Troponin T also remains elevated longer than total LD.3 Its levels can be measured for up to 14 days.5 Thus, the diagnostic window is broader due to the length of time troponin T is elevated in serum. The time interval of elevation in serum ranges from three hours to > 14 days.1,5
The specificity and sensitivity of troponin T measurements aid in both the early and late diagnosis of AMI. 6 Troponin T elevations have also been measured in patients with the clinical diagnosis of unstable angina due to the sensitivity of troponin T for detecting minor myocardial damage. In cases of AMI with minimal cardiac damage, low elevations of CK and CK-MB are difficult to interpret due to the presence of normal levels of these enzymes in the blood, and their lack of cardiac specificity. The specificity of troponin T to cardiac tissue is of value in these difficult patients. 4,6
The Elecsys ® Troponin T test principle is based on a two step sandwich with streptavidin microparticles and electrochemiluminescence detection.
Total duration of assay: 9 minutes.
1st incubation: 15 ul of sample, a biotinylated monoclonal troponin T-specific antibody and a monoclonal troponin T-specific antibody labeled with a ruthenium complex react to form a sandwich complex
2nd incubation: after the addition of streptavidin-coated microparticles, the complex becomes bound to the solid phase via interaction of biotin and streptavidin
The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier
Results are determined via a calibration curve which is instrument-specifically generated by 2-point calibration and a master curve provided via the reagent bar code
Here's an analysis of the provided text to extract the requested information about acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance:
The document focuses on demonstrating substantial equivalence to a predicate device rather than explicitly stating acceptance criteria and then proving the device meets them. Instead, it directly compares the performance characteristics of the new device (Elecsys Troponin T) with the predicate device (Cardiac T Troponin T Enzymun Test). Therefore, the "acceptance criteria" are implied by the performance of the predicate device and the new device's ability to demonstrate comparable or superior performance.
| Feature | Predicate Device (Cardiac T Troponin T Enzymun Test) | New Device (Elecsys Troponin T) | Implied Acceptance Criteria (relative to predicate) |
|---|---|---|---|
| NCCLS (modified) Precision | Comparable or better precision | ||
| Within-run %CV | Sample CC1: 8.6 | Sample CC1: 5.12 | Lower %CV (better precision) |
| Sample CC2: 2.3 | Sample CC2: 2.94 | Comparable %CV | |
| Sample HS1: 1.3 | Sample HS1: 2.93 | Comparable %CV | |
| Total run %CV | Sample CC1: 18.2 | Sample CC1: 7.23 | Lower %CV (better precision) |
| Sample CC2: 6.6 | Sample CC2: 5.77 | Comparable %CV | |
| Sample HS1: 4.4 | Sample HS1: 5.42 | Comparable %CV | |
| Sensitivity (Lower Detection Limit) | 0.02 ng/ml | 0.01 ng/ml | Lower (better) detection limit |
| Assay range | 0.02 - 15.0 ng/ml | 0.01 - 25.0 ng/ml | Wider range (especially higher end) |
| Method Comparison (vs. Cardiac T Troponin T) | y = 1.07x - 0.02, r = 0.89 (N=233) | y = -0.033 + 0.996x, r = 0.969 (N=54) (Least Squares), OR | |
| y = 0.0094 + 0.96x, r = 0.969 (N=54) (Passing/Bablok) | Strong correlation (r value close to 1) | ||
| Interfering Substances (Hemoglobin) | No interference up to 1 g/dl | No interference up to 1.5 g/dl | Higher tolerance to interference |
| Interfering Substances (Lipemia) | No interference up to 1500 mg/dl | No interference up to 1500 mg/dl | Comparable tolerance to interference |
| Interfering Substances (Bilirubin) | No interference up to 61 mg/dl | No interference up to 36 mg/dl | (Slightly) Lower tolerance to interference |
| Interfering Substances (Biotin) | No interference up to 20 ng/ml | No interference up to 100 mg/dl | Much higher tolerance to interference |
| Specificity (% cross-reaction to 2,000 ng/ml) |
§ 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.