(518 days)
The AggreGuide A-100 AA Assay is a qualitative system to aid in the detection of platelet dysfunction due to aspirin ingestion by those 18 years of age or older in 3.2% citrated venous whole blood using the AggreGuide A-100 instrument. For professional use. This test is not for use in patients with underlying congenital platelet abnormalities, patients with non-aspirin induced acquired platelet abnormalities or in patients receiving non-aspirin antiplatelet agents. The test results should be interpreted in conjunction with other clinical and laboratory data available to the clinician.
The AggreGuide A-100 is a laser light scattering system that detects the level of platelet aggregation induced by arachidonic acid agonist in whole blood in motion. The system consists of an instrument and a disposable assay cartridge with pre-loaded freeze dried agonist. A whole blood sample is added to a disposable cartridge that is preloaded with freeze dried arachidonic acid agonist (AA) in a reaction chamber for an individual test. The amount of platelet aggregation is measured by detecting the laser light scattering caused by platelet aggregates. Aspirin is known to inhibit the level of platelet aggregation, or activity, when blood is mixed with arachidonic acid.
Here's a breakdown of the acceptance criteria and study details for the AggreGuide A-100, based on the provided 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document primarily focuses on demonstrating substantial equivalence to a predicate device, rather than explicit pre-defined quantitative acceptance criteria for all performance aspects. However, it presents clinical performance results for sensitivity and specificity. Based on the clinical testing section, the implicit acceptance criteria are that the device demonstrates a clinically acceptable level of sensitivity and specificity for detecting aspirin-induced platelet dysfunction.
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Sensitivity | 83% (115/138) |
| Sensitivity Lower 95% CI | 76% |
| Sensitivity Upper 95% CI | 89% |
| Specificity (True Negative Rate) | 90% (151/167) |
| Specificity Lower 95% CI | 85% |
| Specificity Upper 95% CI | 94% |
| False Positive Rate | 10% (16/167) |
| False Negative Rate | 17% (23/138) |
(Note: The document directly states "Sensitivity" in a table, and then provides a table titled "Pre 325mg Aspirin" that effectively describes the true negative rate (specificity) and false positive rate. The "Post 325mg Aspirin" table provides the true positive rate (sensitivity) and false negative rate. I've used these to construct the performance table.)
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size:
- Total screened: 169 healthy subjects.
- For aspirin-induced dysfunction detection: 138 subjects were given aspirin and tested.
- For baseline (aspirin absent) assessment: 167 subjects (after 2 exclusions).
- Data Provenance: The document does not explicitly state the country of origin. It indicates it was a clinical testing conducted for the purpose of this submission. The nature of the study (administering aspirin to healthy subjects) suggests a prospective study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not specify the use of experts or their qualifications for establishing ground truth in the clinical study. It describes a "qualitative system to aid in the detection of platelet dysfunction due to aspirin ingestion." The ground truth appears to be established by:
* Aspirin Administration: Whether a subject was given 325 mg of aspirin (to induce platelet dysfunction).
* Clinical Observation/Reference Method (Implied): The study design implies that "aspirin ingestion" itself serves as the ground truth for platelet dysfunction, and the device's ability to detect this is assessed. There's no mention of a separate "gold standard" laboratory test or expert consensus.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method (e.g., 2+1, 3+1). The performance data is presented as direct results from the AggreGuide A-100, compared against the known condition of aspirin ingestion or absence.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
A Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not performed as described in this summary. The study assessed the standalone performance of the AggreGuide A-100, not its effectiveness in assisting human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance study was done. The clinical testing section directly evaluates the AggreGuide A-100 system's ability to detect platelet dysfunction due to aspirin ingestion. The device produces a "Platelet Activity Index (PAI)," and the study assesses how well this PAI correlates with the presence or absence of prescribed aspirin. There is no mention of a human in the loop interpreting the device's output and then making a diagnosis.
7. The Type of Ground Truth Used
The ground truth used was primarily based on aspirin administration.
- "Aspirin 325 mg Present" was the ground truth for aspirin-induced platelet dysfunction.
- "Aspirin 325 mg Absent" was the ground truth for normal platelet function (or at least, not aspirin-induced dysfunction).
This is a form of clinical condition or intervention as ground truth, rather than pathology, expert consensus, or outcomes data in the traditional sense for diagnostic assays.
8. The Sample Size for the Training Set
The document does not mention a separate training set or its sample size. The description of performance testing focuses solely on the clinical validation study described. For a device like this (an in-vitro diagnostic instrument), "training" might refer to internal development and calibration, but a distinct "training set" for statistical model development and validation as seen in AI/ML products is not discussed.
9. How the Ground Truth for the Training Set Was Established
Since a separate training set is not explicitly mentioned as distinct from the reported clinical testing, the method of establishing its ground truth is not provided.
§ 864.5700 Automated platelet aggregation system.
(a)
Identification. An automated platelet aggregation system is a device used to determine changes in platelet shape and platelet aggregation following the addition of an aggregating reagent to a platelet-rich plasma.(b)
Classification. Class II (performance standards).