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The Ultegra® Rapid Platelet Function Assay-ASA (RPFA-ASA) is a qualitative test to aid in the detection of platelet dysfunction due to aspirin (ASA) ingestion in citrated whole blood for the point of care or laboratory setting.

Not for use in patients with underlying congenital platelet abnormalities, patients with non-ASA induced acquired platelet abnormalities or in patients receiving non-ASA anti-platelet agents (may be used in patients treated with selective COX-2 inhibitors, e.g., celecoxib (Celebrex®) and rofecoxib (Vioxx®)).

The Ultegra System is a turbidimetric based optical detection system which measures platelet induced aggregation as an increase in light transmittance. The system consists of a stand-alone analyzer and disposable test cartridge with reagents based on microbead agglutination technology. The quality control system includes an electronic control and two levels of liquid control. The analyzer controls assay sequencing, establishes the assay temperature, controls the reagent-sample mixing for the required duration, determines the degree of platelet function, displays the results and status information to the user, and performs self-diagnostics.

The test cartridge contains a lyophilized preparation of human fibrinogen coated beads, platelet agonist, buffer, and preservative. The patient sample is citrated whole blood, which is automatically dispensed from the blood collection tube into the test cartridge by the analyzer, with no blood handling required by the user. Fibrinogen-coated microparticles are used in the Ultegra RPFA-ASA cartridge to bind to available platelet receptors. When the activated platelets are exposed to the fibringgen-coated microparticles, agglutination occurs in proportion to the number of available platelet receptors. To ensure consistent and uniform activation of the platelets, cationic propyl gallate (c-PG) is incorporated into the assay cartridge to induce platelet activation without fibrin formation. The Ultegra Analyzer is designed to measure this agglutination as an increase in light transmittance. Utregra RPFA-ASA Assay results are reported as Aspirin Reaction Units (ARU).

Acceptance Criteria and Device Performance Study for Accumetrics Ultegra® System Rapid Platelet Function Assay -ASA (RPFA-ASA)

1. Table of Acceptance Criteria and Reported Device Performance

Note: The document does not explicitly state numerical acceptance criteria for sensitivity and specificity. The implied criteria are that the device performance should be acceptable for its intended use as a qualitative test to aid in the detection of platelet dysfunction due to aspirin ingestion.

2. Sample Size and Data Provenance

• Test Set Sample Size:
  • "ASA Present" group (Post-ASA): 143 samples
  • "ASA Absent" group (Pre-ASA): 140 samples
  • Total Patients: 148 patients (each patient provided samples at two time points: pre-ASA and post-ASA).
• Data Provenance:
  • Country of Origin: Not specified in the provided document, but the study was a multi-center clinical trial.
  • Retrospective or Prospective: Prospective. Samples were obtained from subjects before and after aspirin ingestion as part of the trial design.

3. Number of Experts Used to Establish Ground Truth & Qualifications

Not applicable. The ground truth for this study was established based on documented aspirin ingestion status, not expert interpretation of results.

4. Adjudication Method for the Test Set

Not applicable. The ground truth was based on the aspirin ingestion status of the patients. The device results (ARU

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