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The QStat Cartridge is a multi-channel cartridge that provides semi-quantitative indications of the coagulation and clot lysis state of a 3.2% citrated venous or arterial whole blood sample using the Quantra Hemostasis Analyzer. The QStat Cartridge includes tests to assess coagulation via the intrinsic and extrinsic pathways and includes a test with tranexamic acid to evaluate clot lysis characteristics.

The QStat Cartridge is intended for in vitro diagnostic use by trained professionals at the point-of-care and in clinical laboratories to evaluate the viscoelastic properties of whole blood by means of the following functional parameters: Clot Time (CT), Clot Stiffness (CS), Fibrinogen Contribution to Clot Stiffness (FCS), Platelet Contribution to Clot Stiffness (PCS), and Clot Stability to Lysis (CSL).

The QStat Cartridge is indicated for the evaluation of blood coagulation and clot lysis in patients age 18 years and older to assess possible hypocoagulable and hypercoagulable conditions in trauma, liver transplantation, and peripartum obstetric procedures.

Results obtained with the QStat Cartridge should not be the sole basis for patient diagnosis.

For prescription use only.

The QStat Cartridge is a single-use, multi-channel disposable plastic cartridge used with the Quantra Hemostasis Analyzer for the evaluation of blood coagulation and clot lysis. The measurements are performed in four test channels of the disposable cartridge which enable differential testing with different sets of reagents without the need for any reagent preparation or controlled pipetting. The cartridge utilizes a citrated evacuated blood collection tube filled with a patient whole blood sample The proprietary technology SEER Sonorheometry measures the evolution of shear modulus (i.e., clot stiffness) in all four channels as a function of time. The QStat Cartridge is intended for use in patients 18 years or older by professionals in a hospital setting (point of care or laboratory) to assess possible hypocoagulable and hypercoagulable conditions in trauma and liver transplantation procedures.

Each QStat Cartridge is pre-filled with lyophilized reagent beads individually sealed in an airtight pouch. After a QStat Cartridge is removed from its primary packaging, it is inserted into the instrument dock. A whole blood sample, collected in a 3.2% sodium citrate anticoagulant blood collection tube (minimum volume 2.7 mL), is attached directly to the cartridge and the test is initiated using the touch screen interface on the Quantra Hemostasis Analyzer. The cartridge is the only component of the Quantra System that is in direct contact with blood. The fluidic system within the instrument draws the sample into the cartridge where it is warmed to 37°C, aliquoted, introduced and mixed with the lyophilized reagents, and analyzed. When the test is complete, the cartridge is released from the dock to be disposed of in an appropriate biosafety sharps container.

The analyzer displays the test results (n=5) in three different views: dial display screen, stiffness curves data, and trend screen. The dial display screen is the primary viewing screen and has a dial for each of the five output parameters. Each dial shows the reference range, assay measurement range, parameter abbreviation, and the numerical result for the corresponding parameter. The stiffness curves are a graphical display of shear modulus measurements over time that enable the user to view the development of clot stiffness over time. The trends screen displays results from a patient for up to six time points.

There are two levels of external QStat Controls (QSL1 and QSL2) that are supplied separately (required but not provided materials) for testing on the Quantra System when changing cartridge lots, changing control lots, or after significant changes are made to the Quantra instrument (e.g., software update).

The FDA 510(k) clearance letter for the Quantra QStat Cartridge describes its intended use for evaluating blood coagulation and clot lysis, specifically extending its indication to peripartum obstetric patients. The submission refers to non-clinical and clinical tests to demonstrate the device meets acceptance criteria.

Here's a breakdown of the requested information based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state quantitative acceptance criteria in a table format. However, it describes acceptable performance in relation to interference and clinical agreement.

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

• Sample Size (Clinical Study): 322 subjects
• Data Provenance: Prospective observational study, conducted across seven clinical sites in the US. The study involved parturients (women in labor) aged 18 years or older with concerns for coagulopathy.
• Sample Size (Interference Study): Not explicitly stated with a specific number for the test set, but it mentioned "normal and hypercoagulable whole blood specimens" and that the "number of replicates at each level of a screening study was targeted to provide a 95% confidence interval (2-sided), per CLSI EP07-A2 Guideline."

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

The document does not specify the number or qualifications of experts used to establish ground truth for the clinical test set. Instead, ground truth for some parameters appears to be established by comparison to other legally marketed and established devices (ROTEM delta, TEG 5000) and conventional coagulation testing (aPTT, PT/INR, fibrinogen level, platelet count).

4. Adjudication Method for the Test Set

The document does not describe an adjudication method involving experts for establishing ground truth. The comparison is made against existing, accepted methods and devices.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

There is no mention of a multi-reader multi-case (MRMC) comparative effectiveness study, nor any effect size regarding human reader improvement with or without AI assistance. This device is an in vitro diagnostic (IVD) device that measures coagulation parameters, not an AI-assisted diagnostic imaging or interpretation tool.

6. Standalone (Algorithm Only) Performance Study

Yes, the studies described are standalone performance studies. The clinical and analytical specificity studies evaluate the performance of the QStat Cartridge and Quantra Hemostasis Analyzer directly, not in conjunction with human interpretation for the primary measurement. The comparisons are to other standalone diagnostic methods (ROTEM delta, TEG 5000, conventional coagulation tests).

7. Type of Ground Truth Used

The ground truth used for the clinical performance evaluation was based on:

• Comparison to legally marketed viscoelastic testing devices: ROTEM delta or TEG 5000.
• Comparison to conventional coagulation testing: aPTT, PT/INR, fibrinogen level, platelet count.
• The "concern for coagulopathy" as a trigger for testing suggests clinical suspicion as an initial selection criterion, with the aforementioned tests serving as the gold/reference standard for comparison.

8. Sample Size for the Training Set

The document does not provide information about a separate training set or its sample size. The studies described appear to be focused on performance validation.

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

As no training set is mentioned, there is no information on how its ground truth was established.

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