← Product Code [QFR](/submissions/HE/subpart-f%E2%80%94automated-and-semi-automated-hematology-devices/QFR) · K251404

# Quantra QStat Cartridge (K251404)

_Hemosonics, LLC · QFR · Aug 25, 2025 · Hematology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/HE/subpart-f%E2%80%94automated-and-semi-automated-hematology-devices/QFR/K251404

## Device Facts

- **Applicant:** Hemosonics, LLC
- **Product Code:** [QFR](/submissions/HE/subpart-f%E2%80%94automated-and-semi-automated-hematology-devices/QFR.md)
- **Decision Date:** Aug 25, 2025
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 864.5430
- **Device Class:** Class 2
- **Review Panel:** Hematology

## Indications for Use

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.

## Device Story

Single-use, multi-channel disposable plastic cartridge; used with Quantra Hemostasis Analyzer. Inputs: 3.2% citrated venous or arterial whole blood. Technology: SEER Sonorheometry measures shear modulus (clot stiffness) evolution over time in four channels containing lyophilized reagents (kaolin, thromboplastin, tranexamic acid, polybrene, abciximab). Outputs: Clot Time (CT), Clot Stiffness (CS), Fibrinogen Contribution (FCS), Platelet Contribution (PCS), Clot Stability to Lysis (CSL). Used in point-of-care or clinical labs by trained professionals. Instrument warms sample to 37°C, aliquots, mixes with reagents, and analyzes. Results displayed on touchscreen as dials, stiffness curves, or trends. Assists clinicians in evaluating coagulation status and guiding interventions for coagulopathy; benefits include rapid assessment of viscoelastic properties to manage bleeding or clotting risks.

## Clinical Evidence

Multi-center prospective observational study (n=322) in parturients ≥18 years. Compared QStat results to ROTEM delta/TEG 5000 and conventional coagulation tests. Primary endpoints: clinical agreement of CSL parameter for fibrinolysis detection and correlation of FCS with fibrinogen levels. Results: 92% agreement between QStat CSL and ROTEM delta EXTEM ML for lysis detection; Passing-Bablok regression for FCS vs. fibrinogen showed good agreement (r=0.815). Analytical specificity study confirmed no significant interference from obstetric-related drugs (hemabate, methergine, misoprostol, oxytocin).

## Technological Characteristics

Single-use plastic cartridge; SEER Sonorheometry (ultrasound-based); 37°C incubation; automated fluidics. Reagents: kaolin, thromboplastin, tranexamic acid, polybrene, abciximab. Outputs: CT (seconds), CS (hPa), FCS (hPa), PCS (hPa), CSL (%). Connectivity: Quantra Hemostasis Analyzer interface. Sterilization: Not specified.

## Regulatory Identification

A coagulation system for the measurement of whole blood viscoelastic properties in perioperative patients is an in vitro diagnostic device used to evaluate blood coagulation, fibrinolysis, or both, in perioperative patients, as an aid in the assessment of coagulopathies when used in conjunction with clinical signs and symptoms and other clinical and laboratory findings.

## Special Controls

The special controls for this device are:

*Classification.* Class II (special controls). The special controls for this device are:(1) Design verification and validation must include detailed documentation of, and results from, the following:
(i) A study assessing precision using protocols determined to be acceptable by FDA, to cover the measurement range for each reported parameter (test output). Testing must include native specimens with coagulation profiles representative of the intended use population. In order to cover the measuring range, testing may include a limited number of contrived specimens, not to exceed 10 to 20 percent, or as otherwise deemed appropriate by FDA. The contrived specimens must be prepared to resemble clinical specimens. This testing must evaluate repeatability and reproducibility and provide assessments of within-run, within-day, between-run, between-day, between-reagent lot, between-instrument, between-site, and between-operator precision, as applicable to the system;
(ii) Studies that demonstrate the performance of each parameter (test output) throughout the claimed measurement range, to include linearity studies or dose-response studies, as applicable to the parameter (test output);
(iii) Potential interferent study that includes evaluation of hemolyzed and lipemic samples as potential interferents; exogenous and endogenous interferents associated with each patient population intended for use with the device, and which might be expected to affect assay performance, must be evaluated; and potential interferents that are specific for, or related to, the technology or methodology of the device. Evaluation of all potential interferents must be performed using a protocol determined to be acceptable to the FDA (
*e.g.,* an FDA-recognized standard) and include both normal and abnormal specimens covering coagulation profiles representative of the intended use population;(iv) A study that evaluates specimen stability under the intended conditions for specimen collection, handling, and storage, using samples that cover the coagulation profiles representative of the intended use population, and using protocols determined to be acceptable by FDA;
(v) A multisite clinical study, determined to be acceptable by FDA, demonstrating performance, relative to clinically relevant and clinically validated laboratory test(s) for each parameter (test output). Further, the study must meet all of the following criteria:
(A) The study must be performed in the intended use population and include representation from all patient populations for whom the device is intended to be used. Potential endogenous and exogenous interferents for each target patient population must be evaluated or known prior to the study;
(B) The study must be conducted at a minimum of three external sites representative of the intended use setting by the intended operators;
(C) Test samples must be collected at time intervals relevant to the device's use in the intended use population;
(D) Clinical specimens, which cover coagulation profiles representative of the intended use population, must be evaluated at each of the three clinical sites in the study;
(E) Analysis of the concordance of clinical interpretation of patient coagulation status made from individual test parameter (test output) results as compared to clinical interpretation of coagulation status from a clinically relevant laboratory test or tests (
*e.g.,* a comparative viscoelastic device or standard laboratory tests) must be conducted; and(F) Expected (reference) values for each parameter (test output) must be demonstrated by testing a statistically appropriate number of samples from apparently healthy normal individuals;
(vi) For a device with a user interface that has information that needs to be interpreted by the user in correctly using the device to achieve the intended test results or a device that does not provide a final output that is a comprehensive interpretation of all parameter (test output) results, a study evaluating the ability of device users to correctly interpret results;
(vii) For any device indicated to guide blood product use, a clinical outcome study determined to be acceptable by FDA that specifically validates the device's indicated use in guiding blood product use; and
(viii) For any device indicated to guide use of medication, a clinical outcome study determined to be acceptable by FDA that specifically validates the device's indicated use in guiding use of medication.
(2) The labeling required under § 809.10(b) of this chapter must include the following:
(i) A summary of results from the study required by paragraph (b)(1)(i) of this section, including repeatability, reproducibility, and assessments of within-run, within-day, between-run, between-day, between-reagent lot, between-instrument, between-site, and between-operator precision, as applicable to the system.
(ii) The claimed measurement range of each parameter (test output), as supported by demonstrated performance of the parameter (test output) throughout the claimed measurement range, including studies required by paragraphs (b)(1)(i) through (iii) and (v) of this section, and, if applicable, paragraphs (b)(1)(vii) and (viii) of this section.
(iii) Identification of known interferents, including all endogenous, exogenous, technology-specific, and patient population-specific interferents, specific to each parameter (test output). The information must include the concentration(s) or level(s) at which interference was found to occur and the concentration range or levels at which interference was not found to occur.
(iv) Information regarding the multisite clinical study required by paragraph (b)(1)(v) of this section, including:
(A) Each patient population evaluated;
(B) Each intended use setting and the operators;
(C) A summary of the results, including the concordance analysis to clinically relevant laboratory test(s); and
(D) Demonstrated expected (reference) values for each parameter (test output).
(3) The labeling required under § 809.10 of this chapter must include the following:
(i) A limiting statement that the result(s) from the device is(are) not intended to be used as the sole basis for a patient diagnosis.
(ii) Unless appropriate clinical outcome studies are done in accordance with paragraph (b)(1)(vii) of this section that specifically validate an indication for the device's use in guiding blood product use, a limiting statement that the device has not been evaluated to guide blood product use.
(iii) Unless appropriate clinical outcome studies are done in accordance with paragraph (b)(1)(viii) of this section that specifically validate an indication for the device's use in guiding use of medication, a limiting statement that the device has not been evaluated to guide use of medication.

## Predicate Devices

- QStat Cartridge ([K240045](/device/K240045.md))

## Submission Summary (Full Text)

> This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com.
>
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FDA

U.S. FOOD & DRUG

ADMINISTRATION

# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

ASSAY ONLY

## I Background Information:

A 510(k) Number

K251404

B Applicant

HemoSonics, LLC

C Proprietary and Established Names

QStat Cartridge

D Regulatory Information

|  Product Code(s) | Classification | Regulation Section | Panel  |
| --- | --- | --- | --- |
|  QFR | Class II | 21 CFR 864.5430 - Coagulation System for The Measurement Of Whole Blood Viscoelastic Properties In Perioperative Patients | HE - Hematology  |

## II Submission/Device Overview:

A Purpose for Submission:

Expansion in indications for use to include patients undergoing peripartum obstetric procedures.

B Measurand:

Clot Time (CT), Clot Stiffness (CS), Fibrinogen Contribution to Clot Stiffness (FCS), Platelet Contribution to Clot Stiffness (PCS), and Clot Stability to Lysis (CSL)

C Type of Test:

Semi-quantitative

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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K251404 - Page 2 of 15

## III Intended Use/Indications for Use:

### A Intended Use(s):
See Indications for Use below.

### B Indication(s) for Use:
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.

### C Special Conditions for Use Statement(s):
Rx - For Prescription Use Only

For in vitro diagnostic use

### D Special Instrument Requirements:
Quantra Hemostasis Analyzer

## IV Device/System Characteristics:

### A Device Description:
The QStat Cartridge is a single-use, multi-channel disposable plastic cartridge used with the Quantra Hemostasis Analyzer to assess a patient's coagulation and clot lysis in a clinical setting (point-of-care or clinical laboratory) during trauma, liver transplantation and peripartum obstetric procedures. The QStat cartridge consists of four independent test channels that can be tested simultaneously with Sonic Estimation of Elasticity via Resonance (SEER) Sonorheometry.

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

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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.

Each channel of the cartridge contains prefilled lyophilized reagents in the form of beads that enable differential testing without the need for any reagent preparation or pipetting before testing. The assay provides the following information for each patient sample: Clot Time (CT), Clot Stiffness (CS), Fibrinogen Contribution to Clot Stiffness (FCS), Platelet Contribution to Clot Stiffness (PCS) and Clot Stability to Lysis (CSL).

QStat Cartridge Reagents and Test function per Channel

|  Channel | Reagents | QStat Cartridge Output Parameter (units of measure)  |
| --- | --- | --- |
|  Measured Parameters  |   |   |
|  1 | Kaolin, calcium, buffers, and stabilizers | Clot Time (CT) (seconds)  |
|  2 | Thromboplastin, tranexamic acid (TXA), polybrene, calcium, buffers, and stabilizers | No direct output (see calculated parameters)  |
|  3 | Thromboplastin, polybrene, calcium, buffers, and stabilizers | Clot Stiffness (CS) (hectopascals)  |
|  4 | Thromboplastin, polybrene, abciximab, calcium, buffers, and stabilizers | Fibrinogen Contribution to Clot Stiffness (FCS) (hectopascals)  |
|  Calculated Parameters  |   |   |
|  2 & 3 | See above | Clot Stability to Lysis (CSL) (percent)  |
|  3 & 4 | See above | Platelet Contribution to Clot Stiffness (PCS) (hectopascals)  |

The analyzer displays the test results 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). QC is manufactured by HemoSonics and will be commercially available separately from the Quantra Hemostasis Analyzer and QStat Cartridge. The QSL1 and QSL2 are recommended to be run monthly, changing cartridge lots, changing control lots, or after significant changes are made to the Quantra instrument (e.g., software update). QSL1 and QSL2 are reconstituted by the end user with the provided diluent and loaded onto the QStat by the same method as patient samples. The plastic diluent vial is shipped with an extender that serves to guide the vial into the cartridge's

K251404 - Page 3 of 15

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evacuated sample tube attachment, after reconstitution. The QStat Controls contain materials to test the measured output parameters for the QStat Cartridge: CT, CS, and FCS, as well as the calculated parameters, CSL and PCS.

## Principle of Operation:

The QStat Cartridge uses Sonic Estimation of Elasticity via Resonance (SEER) Sonorheometry, an ultrasound-based technology, which uses ultrasonic pulses to quantify the shear modulus (i.e., stiffness) of a blood sample during the process of coagulation and clot lysis. A focused ultrasound pulse is transmitted into the blood sample to generate a shear wave, causing the sample to resonate once the clot begins to form. Multiple parameters measured from the four channels of the cartridge provide information about the functional role of the coagulation factors, fibrinogen, platelets, and clot lysis factors in the sample.

## Clot Time (CT) Test

CT is directly measured in Channel #1 using kaolin to provide contact surface activation of coagulation via the intrinsic pathway. Kaolin is an aluminum silicate mineral with a negatively charged surface. Calcium acetate is included to re-calcify the blood sample used for testing. Prolongation of the intrinsic pathway clot time is likely due to deficiencies in intrinsic pathway coagulation factors, presence of anticoagulants, or inhibitors that affect the intrinsic pathway.

## Clot Stiffness (CS) Test

CS is directly measured in Channel #3 and is determined by measuring the stiffness after the clot has formed using thromboplastin (tissue factor) to activate the extrinsic pathway of coagulation. The test includes polybrene, a reagent that neutralizes heparin. Calcium acetate is included to re-calcify the blood sample used for testing. This test allows an evaluation of the total clot stiffness from the combined contributions from both platelets and fibrinogen.

## Fibrinogen Contribution to Clot Stiffness (FCS) Test

FCS is directly measured in Channel #4 using thromboplastin (tissue factor) to activate the extrinsic pathway of coagulation, in combination with a reagent that inhibits platelet aggregation and contraction (Abciximab). Abciximab is the Fab fragment of a monoclonal antibody that binds on the platelet surface receptor GPIIb/IIIa. Polybrene is included to neutralize heparin in addition to calcium acetate to re-calcify the blood sample used for testing. This test allows an evaluation of the contribution of functional fibrinogen to clot stiffness without the effect of heparin anticoagulation. In addition, when used in combination with the Clot Stiffness (CS) Test, the contribution of platelets to the clot stiffness can be determined.

Two additional functional parameters are calculated:

## Platelet Contribution to Clot Stiffness (PCS)

PCS is a functional parameter that is calculated as the difference between the overall CS measured in Channel #3 and the FCS measured in Channel #4, reported in hectopascals (hPa).

## Clot Stability to Lysis (CSL)

CSL is a functional parameter that is calculated from Channel #2 and #3 and is reported as a percent after the maximum stiffness in Channel #3 is detected. The CSL reports the loss in clot stiffness that is likely due to the influence of fibrinolysis on a scale from 100% (no clot lysis) to 10% (significant clot degradation).

K251404 - Page 4 of 15

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V Substantial Equivalence Information:

A Predicate Device Name(s):
QStat Cartridge, ROTEM delta Thromboelastometry System, EXTEM Assay, FIBTEM Assay, APTEM Assay for ROTEM delta Thromboelastometry System

B Predicate 510(k) Number(s):
K213917, K083842, K101533

C Comparison with Predicate(s):

|  Device & Predicate Device(s): | K251404 | K240045 | K083842 | K101533  |
| --- | --- | --- | --- | --- |
|  Device Trade Name | QStat Cartridge | QStat Cartridge | ROTEM delta Thromboelastometry System | EXTEM Assay, FIBTEM Assay, APTEM Assay for the ROTEM delta Thromboelastometry System  |
|  General Device Characteristic Similarities |  |  |  |   |
|  Intended Use/Indications For Use | 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 | 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 whole blood sample using the Quantra Hemostasis Analyzer. The QStat Cartridge includes tests to assess coagulation via the intrinsic and extrinsic | The ROTEM delta Thromboelastometry System is designed for in vitro diagnostic use by professionals in a laboratory environment. The ROTEM® delta is intended to provide a qualitative and quantitative indication of the coagulation state of a blood sample. For this purpose the ROTEM delta | The EXTEM assay is a semi-quantitative in vitro diagnostic assay used to monitor the coagulation process via the extrinsic pathway in citrated whole blood specimens on the ROTEM delta Thromboelastometry System. Clotting characteristics are described by the functional parameters Clotting Time  |

K251404 - Page 5 of 15

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K251404 - Page 6 of 15
|   | 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 | 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 and liver | records the clot firmness changes in a sample of citrated whole blood as the sample clots, retracts and lyses in real time. The analyzer output consists of a qualitative graphical representation (mirrored coagulation curve – clot firmness over time) and several defined numerical parameters describing the curve quantitatively. The in-TEM assay is a semi-quantitative in vitro diagnostic assay used to monitor the coagulation process via the intrinsic pathway in citrated whole blood specimens. Clotting characteristics are described by the functional parameters Clotting Time (CT), Speed of Clot formation (CFT and alpha angle), Clot Firmness (A20/MCF) and Clot Lysis (LOT, ML, LI(x)). The | (CT), Speed of Clot formation (CFT and alpha angle), Clot Firmness (A20/MCF) and Clot Lysis (LOT, ML, LI(x)), CFT and alpha (Speed of Clot Formation) are complementary parameters and should be used in conjunction with the main parameters Clotting Time (CT) and Clot Firmness (A20/MCF). The FIBTEM assay is a semi-quantitative in vitro diagnostic assay on the ROTEM delta Thromboelastometry System to monitor the clot firmness of a citrated whole blood specimen after blocking platelet contribution to the clot firmness. The fibTEM® is always used in conjunction with exTEM® Clotting characteristics are described by the functional parameter Clot Firmness (A20/MCF). The  |
| --- | --- | --- | --- | --- |

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K251404 - Page 7 of 15
|   | 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. | transplantation procedures. Results obtained with the QStat Cartridge should not be the sole basis for patient diagnosis. For prescription use only. | assay is intended for professional use in the clinical laboratory on the ROTEM delta Instrument. The hep-TEM assay is a semi-quantitative in vitro diagnostic assay used to monitor the coagulation process via the intrinsic pathway in the presence of heparin, in citrated whole blood specimens. Clotting characteristics are described by the functional parameters Clotting Time (CT), Speed of Clot formation (CFT and alpha angle), Clot Firmness (A20/MCF) and Clot Lysis (LOT, ML, LI(x)). The assay is intended for professional use in the clinical laboratory on the ROTEM delta Instrument. The NATEM assay is a semi-quantitative in vitro diagnostic assay used to monitor the coagulation process contact activated by the | APTEM® assay is a semi-quantitative in vitro diagnostic assay on the ROTEM delta Thromboelastometry System to monitor the clot firmness of a citrated whole blood specimen after blocking hyperfibrinolysis by aprotinin. The ap-TEM is always used in conjunction with ex-TEM. Clotting characteristics are described by the functional parameters Clotting Time (CT), Speed of Clot formation (CFT and alpha angle), Clot Firmness (A20/MCF) and Clot Lysis (LOT, ML, LI(x)). CFT and alpha (Speed of Clot Formation) are complementary parameters and should be used in conjunction with the main parameters Clotting Time (CT) and Clot Firmness (A20/MCF). Each assay, APTEM, EXTEM and  |
| --- | --- | --- | --- | --- |

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K251404 - Page 8 of 15
|   |  |  | surface of the measurement cell, in citrated whole blood specimens. Clotting characteristics are described by the functional parameters Clotting Time (CT), Speed of Clot formation (CFT and alpha angle), Clot Firmness (A20/MCF) and Clot Lysis (LOT, ML, LI(x)). The assay is intended for professional use in the clinical laboratory on the ROTEM delta Instrument. The star-TEM reagent is intended for use as recalcification reagent in the NATEM and in-TEM on the ROTEM delta Thromboelastometry System. | FIBTEM is performed on the ROTEM delta analyzer which has the following indication for use: The indication for ROTEM® delta is in adult patients when an evaluation of their blood coagulation properties is desired. Coagulation evaluations with the ROTEM® delta system are commonly used to assess clinical conditions in organ transplantation, cardiovascular surgery, cardiology procedures and trauma to access post-operative hemorrhage and/or thrombosis.  |
| --- | --- | --- | --- | --- |
|  Sample Type | 3.2% sodium citrated whole blood, 3.2% citrated arterial whole blood | 3.2% sodium citrated whole blood | Citrated whole blood | Citrated whole blood  |
|  Results Display | Graphical (curves) and numerical display of patient results | Same | Same | Same  |
|  Measurands | Clot time (CT) | Same | Same | Same  |
|   |  Clot Stiffness (CS) | Same | Same Reported as | Same Reported as  |

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K251404 - Page 9 of 15
|   |  |  | EXTEM A20
(Clot Firmness) | EXTEM A20
(Clot Firmness)  |
| --- | --- | --- | --- | --- |
|   |  Fibrinogen Contribution to Clot Stiffness (FCS) | Same | Same
Reported as FIBTEM A20 | Same
Reported as FIBTEM A20  |
|  **Reagents**
(extrinsic pathway) | Thromboplastin | Same | Same | Same  |
|  **General Device Characteristic Differences** |  |  |  |   |
|  Sample Volume | 3.0 mL citrated whole blood sample (2.7 mL whole blood + citrate) | Same | 300 µL per assay (in-TEM Assay, hep-TEM Assay, NATEM Assay, star-TEM) | 300 µL per assay (EXTEM Assay, FIBTEM Assay, APTEM Assay)  |
|  Sample Preparation | Automated | Automated | Manual | Manual  |
|  Signal Generation | Ultrasonic pulses directed into a stationary well | Same | Oscillating pin in stationary cup | Oscillating pin in stationary cup  |
|  Assay Output | Platelet Contribution to Clot Stiffness (PCS) | Same | Output not directly provided but can be calculated offline from comparison of EXTEM and FIBTEM | Output not directly provided but can be calculated offline from comparison of EXTEM and FIBTEM  |
|   |  Clot Stability to Lysis (CSL) | Same | EXTEM and APTEM ML/LI60 and difference calculated offline. | EXTEM and APTEM ML/LI60 and difference calculated offline.  |
|  Reagents | Kaolin (intrinsic pathway activator) | Same | Ellagic acid (intrinsic pathway activator) | Ellagic acid (intrinsic pathway activator)  |
|   |  Abciximan (platelet inhibitor) | Same | Cytochalasin D (platelet inhibitor) | Cytochalasin D (platelet inhibitor)  |
|   |  Tranexamic acid (fibrinolysis inhibitor) | Same | Aprotinin (fibrinolysis inhibitor) | Aprotinin (fibrinolysis inhibitor)  |

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|  Principle of Operation | SEER
Sonorheometry uses ultrasound pulses to quantify the shear modulus (i.e., stiffness) of a blood sample during the process of coagulation and clot lysis. A focused ultrasound pulse is transmitted into the blood sample to generate a shear wave, causing the sample to resonate once the clot begins to form. | Same | Shear elasticity of a coagulating sample by motion of an oscillating pin in a stationary cup. The motion of the pin is detected by an optical detection system. Data are processed and analyzed by a computer with special software. | Shear elasticity of a coagulating sample by motion of an oscillating pin in a stationary cup. The motion of the pin is detected by an optical detection system. Data are processed and analyzed by a computer with special software.  |
| --- | --- | --- | --- | --- |

VI Standards/Guidance Documents Referenced:

CLSI EP28: Defining, Establishing and Verifying Reference Intervals in the Clinical Laboratory; Approved Guideline - Third Edition

CLSI EP07: Interference Testing in Clinical Chemistry; Approved Guideline Third Edition

CLSI EP09: Measurement Procedure Comparison and Bias Estimation Using Patient Samples, Third Edition

VII Performance Characteristics (if/when applicable):

A Analytical Performance:

1. Precision/Reproducibility:
Refer to K213917.

2. Linearity:
Not applicable.

3. Analytical Specificity/Interference:

K251404 - Page 10 of 15

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The interference study evaluated the following potential interferents: hemabate (carboprost tromethamine), methergine (methylergonovine maleate), misoprostol, and oxytocin (Pitocin) and involved testing of each interferent with normal and hypercoagulable whole blood specimens. Hypercoagulable specimens consisted of fibrinogen-spiked specimens (whole blood with elevated fibrinogen). Potential sources of interference were tested both at one level of interferent ("Test") and without interferent ("Control").

Each exogenous interferent was tested with normal whole blood and hypercoagulable fibrinogen-spiked whole blood. If interference was observed for either specimen, the concentration at which interference occurred for that specimen would be identified by a dose-response study. If no interference was observed, additional studies were performed with the remaining two hypercoagulable sample types. If no interference was observed for normal whole blood and the three (3) hypercoagulable specimen types an analyte was considered to not interfere up to the highest level tested, then no additional testing was performed.

The following table shows the highest concentration at which each substance showed no significant interference in whole blood samples collected in 3.2% sodium citrate anticoagulant collection tubes.

|  Potential Interferent | Concentration  |
| --- | --- |
|  Hemabate | 9.291 ng/mL  |
|  Methergine | 17.754 ng/mL  |
|  Misoprostol | 2.43 ng/mL  |
|  Oxytocin | 0.09 ng/mL  |

4. Assay Reportable Range:

|  QStat Output Parameter | Units | Reportable Ranges  |
| --- | --- | --- |
|  Clot Time (CT) | Seconds | 60 – 480  |
|  Clot Stability to Lysis (CSL) | Percent | 10 – 100  |
|  Clot Stiffness (CS) | hectopascals | 2 – 65  |
|  Platelet Contribution to Clot Stiffness (PCS) | hectopascals | 2 – 50  |
|  Fibrinogen Contribution to Clot Stiffness (FCS) | hectopascals | 0.2 -30  |

5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):

Refer to K213917.

6. Detection Limit:

Not applicable.

7. Assay Cut-Off:

Not applicable.

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B Comparison Studies:

1. Method Comparison with Predicate Device:

a. Comparison with ROTEM delta Thromboelastometry System:

The clinical performance of the QStat Cartridge and the predicate device, ROTEM delta Thromboelastometry System, was evaluated in a multi-center prospective observational study across seven clinical sites in the US involving patients 18 years of age or older. The study included 308 obstetric patients undergoing labored or non-labored delivery for which there was a concern for coagulopathy and 14 healthy, non-pregnant females from which contrived samples were prepared.

Testing was performed upon ordering standard of care coagulation testing or viscoelastic testing for suspected coagulopathy and, in some cases, at the time of hemorrhage or after hemorrhage when blood products or other interventions were delivered for up to 4 samples per patient. Contrived samples (6.98%) were prepared by spiking blood samples from normal volunteers with tPA and heparin to broaden the range of comparisons between QStat Cartridge parameters and ROTEM delta parameters. All blood samples were run in parallel on the Quantra QStat Cartridge and the ROTEM delta.

Correlation and clinical agreement analysis were performed to compare measurements obtained with the QStat Cartridge to comparable measures obtained with the ROTEM delta Thromboelastometry System. A linear regression analysis was performed to evaluate the correlation between the QStat parameters and comparable ROTEM delta Thromboelastometry System parameters. For the primary analysis, samples were combined with contrived samples. For the analysis of parameter CT vs INTEM CT, samples from the obstetric study (n=195) were combined with samples from liver transplant and trauma subjects (K213917) to span the analytical measurement range due to the difficulty in obtaining hypocoagulable samples in the peripartum obstetric population. The results met the pre-defined acceptance criteria.

|  Parameter | N | Sample Range | Linear Fit | Slope Estimate (95% CI) | Intercept Estimate (95% CI) | Pearson (95% CI)  |
| --- | --- | --- | --- | --- | --- | --- |
|  CT vs INTEM CT | 585 | 60-480 | CT=67.8+ 0.38* INTEM CT | 0.38 (0.36, 0.40) | 67.8 (62.9, 72.6) | 0.88 (0.86, 0.90)  |
|  CS vs EXTEM A20 (hPa) | 301 | 4.0-62 | CS= -2.522÷ 2.910* EXTEM A20 | 2.910 (2.766,3.053) | -2.522 (-4.1-1.0) | 0.917 (0.897,0.933)  |
|  PCS vs PLATEM (hPa) | 302 | 4.0-48 | PCS = -0.181+ 2.622*PLATEM | 2.622 (2.458, 2.785) | -0.181 (-1.71,1.347) | 0.877 (0.847, 0.900)  |
|  FCS vs FIBTEM A20 (hPa) | 299 | 0.9-23 | FCS=-0.169÷3.233* FIBTEM A20 | 3.233 (2.974,3.492) | -0.169 (-0.55,0.213) | 0.817 (0.776, 0.851)  |

A clinical agreement analysis was performed to evaluate the ability of the QStat CSL parameter to identify fibrinolytic samples relative to the comparable ROTEM delta Thromboelastometry System Lysis parameter EXTEM ML. The overall agreement of patient sample assignments into lysis-positive and lysis-negative based on data for QStat CSL and ROTEM delta EXTEM ML was 99%. Agreement within the lysis-positive and lysis-negative subcategories was 85% and 99%, respectively. These results met the acceptance criteria for overall and subcategory agreements.

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Clinical Agreement Analysis for Comparison of QStat and ROTEM delta Lysis Parameters

|  ROTEM delta EXTEM ML  |   |   |   |   |
| --- | --- | --- | --- | --- |
|  QUANTRA QStat CSL |  | Lysis Positive* | Lysis Negative* | Total  |
|   |  Lysis Positive** | 11 | 1 | 12  |
|   |  Lysis Negative** | 2 | 231 | 233  |
|   |  Total | 13 | 232 | 245  |

**Classification based on Quantra definition of lysis
* Classification based on ROTEM definitions of lysis

Summary Metrics for Clinical Agreement Analysis for Comparison of QStat and ROTEM delta Lysis Parameters

|  Category | Agreement (95% CI)  |
| --- | --- |
|  Lysis Positive | 0.85 (0.54, 0.97)  |
|  Lysis Negative | 0.99 (0.97, 1.0)  |
|  Overall | 0.99 (0.96, 1.0)  |

b. Comparison with Teg 5000 Hemostasis System:

At two clinical sites, 60 samples were analyzed on the QStat Cartridge and the TEG 5000 Hemostasis System. For the correlation analysis, TEG 5000 clot stiffness amplitudes were first converted to units of clot elasticity (hPa). The limited data set was not supplemented with contrived samples, did not span the analytical measuring range, and did not meet the predefined acceptance criteria.

|  Parameter | N | Linear Fit | Slope Estimate (95% CI) | Intercept Estimate (95% CI) | Pearson R (95% CI)  |
| --- | --- | --- | --- | --- | --- |
|  CT vs CK-R | 60 | CT=81.129+ 7.240* CK-R | 7.240 (4.906,9.575) | 81.129 (69.37,92.88) | 0.624 (0.435,0.755)  |
|  CS vs CK-MA (hPa) | 60 | CS= 0.438+ 2.221* TEG MA | 2.221 (1.653,2.79) | 0.438 (-8.21,9.087) | 0.709 (0.551.0.814)  |

Clinical Agreement Analysis for Comparison of QStat Cartridge CSL and TEG 5000 LY30

|   |   | TEG 5000 LY30  |   |   |
| --- | --- | --- | --- | --- |
|  QUANTRA QStat® CSL |  | Lysis Positive* | Lysis Negative* | Total  |
|   |  Lysis Positive** | 0 | 0 | 0  |
|   |  Lysis Negative** | 0 | 57 | 57  |
|   |  Total | 0 | 57 | 57  |

**Classification based on Quantra definition of lysis
* Classification based on TEG 500 definition of lysis

Overall, the agreement between QStat CSL and TEG 5000 LY30 was 100%.

c. Comparison with Conventional Coagulation Tests:

To assess the clinical agreement of QStat test results with results from corresponding conventional coagulation tests (aPTT, fibrinogen, platelet count), samples were categorized as "Low" (decrease in coagulation function) or "Not Low" (adequate or increase in coagulation function) based on clinical guidelines to demonstrate concordance in hypocoagulable samples for the obstetric patient population. The results met the predefined acceptance criteria for overall and subcategory agreements.

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|   | N in Category CT vs aPTT | Agreement CT vs aPTT | N in Category PCS vs Platelets/Fib | Agreement PCS vs Platelet/Fib  |
| --- | --- | --- | --- | --- |
|  Low (L) | 9/9 | 1.0 (0.63, 1.0) | 14/15 | 0.93 (0.66, 1.0)  |
|  Not Low (NL) | 300/309 | 0.97 (0.94, 0.99) | 266/290 | 0.92 (0.88, 0.95)  |
|  Overall | 309/318 | 0.97 (0.95, 0.99) | 280/305 | 0.92 (0.88, 0.95)  |

2. Matrix Comparison:

Not applicable.

C Clinical Studies:

1. Clinical Sensitivity:

Not applicable.

2. Clinical Specificity:

Not applicable.

3. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable):

Reader Study

A reader study was conducted to assess the ability of potential users of Quantra System with the QStat cartridge to correctly interpret results displayed on the Quantra dials display and curve screen for samples analyzed on the QStat Cartridge from obstetric patients. The QStat reader study was conducted with a total of 9 readers who were clinicians who regularly assess the blood coagulation status of patients. Participants were presented with views of Quantra dial displays and curve screens representing a variety of test outcomes that can be anticipated from obstetric patients. For each of 10 cases, a dials display screen was provided containing 5 dials with results for all 5 QStat parameters: CT, CSL, CS, PCS, and FCS. The curves screen showing clot stiffness over time of the 4 test channels was also provided for 2 cases. Each participant answered a total of 60 multiple choice questions for a total of 540 multiple-choice questions. For all QStat parameters, >95% of questions pertaining to each of the displays were answered correctly.

D Clinical Cut-Off:

Not applicable.

E Expected Values/Reference Range:

The reference range study was a multi-center, prospective, observational study aimed at establishing reference range intervals in obstetric patients for the test parameters measured using the Quantra QStat System with the QStat Cartridge. The study population consisted of 129 healthy women (≥18 to 45 years of age) who were pregnant with a single fetus and duration of pregnancy was ≥28 weeks enrolled across three (3) external sites that are representative of the

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general population of the United States. The distribution of the study population was approximately equal across the following categories: 28-32 weeks, 33-36 weeks, >36 weeks.

|  Output Parameter | Units | N | Reference Range  |
| --- | --- | --- | --- |
|  Clot Time (CT) | Seconds | 129 | 97 – 147  |
|  Clot Stability to Lysis (CSL) | Percent | 125 | 94 – 100*  |
|  Clot Stiffness (CS) | hectopascals | 128 | 18.2 – 48.3  |
|  Platelet Contribution to Clot Stiffness (PCS) | hectopascals | 128 | 15.6 – 40.8  |
|  Fibrinogen Contribution to Clot Stiffness (FCS) | hectopascals | 129 | 2.2 – 8.4  |

*The Clot Stability to Lysis (CSL) is a calculated parameter. Samples with CSL values below 90% are indicative of reduction of clot stiffness that is likely due to the influence of fibrinolysis. The 90% threshold was calculated as the lower bound of the 95% confidence interval around the lower limit of the reference interval for CSL determined in healthy volunteers.

## VIII Proposed Labeling:

The labeling supports the finding of substantial equivalence for this device.

## IX Conclusion:

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

K251404 - Page 15 of 15

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**Source:** [https://fda.innolitics.com/submissions/HE/subpart-f%E2%80%94automated-and-semi-automated-hematology-devices/QFR/K251404](https://fda.innolitics.com/submissions/HE/subpart-f%E2%80%94automated-and-semi-automated-hematology-devices/QFR/K251404)

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