Search Results

For the quantitative determination of cardiac troponin I in serum or heparinized plasma using the Bayer Diagnostics ACS:180® and ADVIA® Centaur™ Automated Chemiluminescent Systems. Cardiac troponin I determinations aid in the diagnosis of acute myocardial infarction and in the risk stratification of patients with non-ST segment elevation acute coronary syndromes with respect to relative risk of mortality, myocardial infarction or increased probability of ischemic events requiring urgent revascularization procedures.

Troponin is a structural protein which regulates the contraction of striated muscle. It consists of three subunits which are located periodically along the thin filament of the myofibrils. Troponin C binds calcium, troponin T attaches to tropomyosin on the thin filament, and troponin I inhibits actomyosin ATPase. Troponin I (Tnl), an inhibitory protein of the troponin-tropomyosin complex, exists in three distinct isoforms: cardiac muscle, slow-twitch skeletal muscle, and fast-twitch, skeletal muscle. The cardiac form (cTnl) is further unique having 31 additional amino acid residues on its N-terminal, not present in the skeletal forms, which allows for specific polyclonal and monoclonal antibody development. The cardiac specificity of this isoform improves the accuracy of diagnosis in patients with acute or chronic skeletal muscle injury and possible concomitant myocardial injury, and is the basis for its selection as a cardiac marker in the diagnosis of acute myocardial infarction.

Here's an analysis of the provided text to extract information about the acceptance criteria and the study that proves the device meets them:

Acceptance Criteria and Device Performance for Bayer Diagnostics ACS:180 & ADVIA Centaur Troponin I Immunoassay

The provided document describes the performance characteristics of the Bayer Diagnostics ACS:180 and ADVIA Centaur Troponin I Immunoassay.

1. Table of Acceptance Criteria and Reported Device Performance

Note: The document explicitly states "Acceptance Criteria" for analytical sensitivity and provides results. For method comparison, it provides correlation data, which serves as a measure of agreement between the new device and a predicate, implicitly defining an acceptance threshold for similar performance.

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size for Method Comparison Test Set: 381 samples
• Data Provenance for Method Comparison Test Set: Not explicitly stated but implied to be clinical samples used to compare two devices. The document does not specify country of origin or if it was retrospective/prospective.
• Sample Size for Clinical Performance/Risk Stratification Test Set: 681 patients.
• Data Provenance for Clinical Performance/Risk Stratification Test Set: This was a "multicenter substudy of a clinical trial designed to assess the efficacy of low molecular weight heparin in the treatment of unstable angina and non-Q wave myocardial infarction." The data is prospective in nature, as it involved monitoring clinical outcomes up to 43 days from hospital presentation. Country of origin not specified.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications

The document does not mention the use of experts to establish a "ground truth" for the test set in the traditional sense of medical image interpretation or diagnostic agreement. The ground truth for the clinical performance study likely relied on established clinical outcomes and definitions for events like myocardial infarction, death, and urgent revascularization.

4. Adjudication Method for the Test Set

Adjudication methods (e.g., 2+1, 3+1) are typically used for subjective diagnostic interpretations or image-based studies. This product is an immunoassay, and its clinical performance was assessed against objective clinical endpoints (death, confirmed MI, urgent revascularization). Therefore, no traditional adjudication method as described would be applicable or mentioned.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done

No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic modalities where human readers interpret results (e.g., radiology). The device is an automated immunoassay, and its performance is evaluated objectively by measuring analyte concentrations.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done

Yes, the performance data presented (analytical sensitivity, method comparison) represents the standalone performance of the assay. The clinical performance section also details how the assay results correlated with patient outcomes, demonstrating the algorithm's utility without direct human interpretation of the assay itself being modified or enhanced.

7. The Type of Ground Truth Used

• For Analytical Sensitivity/Method Comparison: The ground truth for these analytical parameters is based on established laboratory standards, reference methods, and comparison against a legally marketed predicate device (Bayer Diagnostics ACS:180 Troponin I Immunoassay).
• For Clinical Performance (Risk Stratification): The ground truth was based on objective clinical outcomes:
  • Death
  • Development of confirmed myocardial infarction after initial hospital presentation
  • Need for urgent revascularization procedures as necessitated by recurrent episodes of angina.

8. The Sample Size for the Training Set

The document does not provide information about a separate "training set" for the assay. For an immunoassay like this, the development process involves reagent optimization, calibration, and validation, which might use various sample sets, but the specific term "training set" (common in AI/ML contexts) is not used. The data reported is for validation and performance assessment.

9. How the Ground Truth for the Training Set Was Established

As no training set is explicitly mentioned, the method for establishing its ground truth is also not detailed. Immunoassays are generally developed and validated against quantitative standards and known samples, rather than a "ground truth" like that established for diagnostic imaging algorithms.

Ask a specific question about this device