TAS PTONE

K955843 · Cardiovascular Diagnostic Services · GJS · Mar 18, 1996 · Hematology

Device Facts

• Record ID: K955843
• Device Name: TAS PTONE
• Applicant: Cardiovascular Diagnostic Services
• Product Code: GJS · Hematology
• Decision Date: Mar 18, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 864.7750
• Device Class: Class 2

Intended Use

The new TAS PT ONE test card, is intended to be used with the TAS Analyzer to determine the prothrombin time in citrated whole blood or plasma.

Device Story

TAS PT ONE Test Card is a single-use diagnostic card for prothrombin time (PT) measurement. Input: citrated whole blood or plasma sample. Operation: card contains calcium chloride, tissue thromboplastin (human placenta), buffer, and stabilizers. Operator inserts card into TAS Analyzer; magnetic stripe provides lot-specific calibration. Sample added to card well; reagent rehydrates, recalcifying sample to initiate clotting. Analyzer monitors movement of paramagnetic iron oxide particles (PIOP) within a magnetic field; clot formation decreases particle movement. Output: clotting time displayed by analyzer. Used in clinical settings; operated by healthcare personnel. Benefits: provides rapid PT assessment for monitoring coagulation status, particularly in patients on anticoagulant therapy.

Clinical Evidence

Clinical study conducted at one hospital comparing TAS PT ONE to predicate TAS PT test card. Sample size: 338 blood and plasma samples from 101 individuals (normal donors and patients on warfarin therapy). Primary endpoint: correlation of clotting time results between the two card types. Results: correlation coefficient > 0.92 across multiple lots. Bench testing confirmed sensitivity to clotting factors II, V, VII, and X, and stability of results across varying fibrinogen levels, hematocrit, and lipid concentrations.

Technological Characteristics

Single-use plastic test card containing calcium chloride, human placenta tissue thromboplastin, buffer, and stabilizers. Employs paramagnetic iron oxide particles (PIOP) for photo-optical clot detection. Features a magnetic stripe for lot-specific calibration data. Operates with the TAS Analyzer. No specific ASTM materials cited. System performs automated self-tests at power-up and during operation.

Indications for Use

Indicated for the determination of prothrombin time in citrated whole blood or plasma samples from patients, including those undergoing warfarin therapy.

Regulatory Classification

Identification

A prothrombin time test is a device used as a general screening procedure for the detection of possible clotting factor deficiencies in the extrinsic coagulation pathway, which involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis or pulmonary embolism).

Predicate Devices

• TAS PT test card (K882456)

Submission Summary (Full Text)

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CARDIOVASCULAR DIAGNOSTICS INC.

RECEIVED
26 Dec 95 13 29
FDA/ADRH/DCE/DHC

VI. Summary of Safety and Effectiveness Information

K955843
MAR 18 1996

510(K) summary

Submitted by: Cynthia Pritchard, Ph.D.
Director of Test Development

Address: Cardiovascular Diagnostic, Inc.
5301 Departure Drive
Raleigh, NC 27604

Phone: [phone], ext. 248

Fax: [phone]

Contact: Cynthia Pritchard, Ph.D.
Director of Test Development

Date of Summary: December 1, 1995

5301 DEPARTURE DRIVE, RALEIGH, NORTH CAROLINA 27604, [phone]
FAX NUMBER 919) 954-9932

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# VI. Summary of Safety and Effectiveness Information

**Trade name:** Thrombolytic Assessment System Prothrombin Time Test Card (TAS PT ONE Test Card)

**Common Name:** TAS PT ONE Test Card

**Classification Name:** systems for in vitro coagulation studies, automated or semiautomated instruments and associated reagents and controls used to perform a series of coagulation studies and coagulation factor assays (Class II. 21 C.F.R. 864.5425)

**Predicate Device:** The proposed TAS PT ONE test card made with thromboplastin from human placenta is substantially equivalent to the marketed TAS PT test card made with rabbit brain thromboplastin (K882456).

**Description of the Device:** The TAS Prothrombin Time, ISI 1 (PT ONE) test card provides a one stage method which measures the clotting time of a sample after combining it with activator. This test consists of a single card that contains calcium chloride to initiate clotting in citrated blood samples, tissue thromboplastin as an activator, buffer, and stabilizers. Samples are tested by drawing venous or arterial blood into a sodium citrate tube and briefly mixing by gentle inversion. This allows the operator to control the start of the clotting reaction which requires recalcification. Because the sample is citrated, additional tests such as an aPTT can be performed with the same sample. The test card has a magnetic stripe on the back which encodes lot specific information such as number, expiration date, and calibration factors specific to that lot. A room temperature test card is removed from the pouch and the card is passed through the instrument's stripe reader to program the instrument to run a PT ONE. The instrument then requests patient and sample information and instructs the operator to insert a PT ONE test card. The card is quickly warmed and the operator is prompted to add a drop of sample to the card well. The sample is drawn into the card and rehydrates the PT ONE reagent which recalcifies the sample and begins the clotting reaction. As the reaction proceeds and clotting begins, the movement of the particles decreases, and the instrument signals the clotting time. Low levels of extrinsic clotting factors will cause prolongation of clotting time.

**Intended Use:** The new TAS PT ONE test card, is intended to be used with the TAS Analyzer to determine the prothrombin time in citrated whole blood or plasma.

5301 DEPARTURE DRIVE, RALEIGH, NORTH CAROLINA 27604, [phone]
FAX NUMBER [phone]

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Summary of Safety and Effectiveness Information
TAS PT ONE Test card

## Comparison of old and new TAS PT test cards

| Characteristic | Cleared PT | proposed PT ONE |
| --- | --- | --- |
| Intended use | determination of prothrombin time | same |
| Card format | flat shallow reaction chamber mounted on a thin plastic card | same |
| Sample type | citrated whole blood or plasma | same |
| Reagent | thromboplastin, plus PIOP a | same |
| Source | rabbit brain | human placenta |
| Reaction | formation of a fibrin clot | same |
| Analyzer | TAS | same |
| Signal monitored | photo-optical detection of PIOP movement in a magnetic field | same |
| Signal interpretation | monitoring of clot formation by decrease in PIOP movement | same |
| Results | clotting time | same |
| Interpretation of results | increase in clotting time indicates low levels or inhibition of clotting factors | same |
| ISI | approx 1.6 | approx 1.0 |
| Quality control | self tests performed by analyzer at power up and throughout operation, plus periodic functional testing of each test card with quality control plasmas | same |
| a paramagnetic iron oxide particles | | |

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5301 DEPARTURE DRIVE, RALEIGH, NORTH CAROLINA 27604, [phone]
FAX NUMBER [phone]

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Summary of Safety and Effectiveness Information
TAS PT ONE Test card

Nonclinical Performance Data: Preclinical testing was done at CDI using TAS PT ONE test cards and the TAS analyzer to determine the performance characteristics of the system. In-house studies showed that the PT ONE test cards responded similarly to different clotting factors, coagulation inhibitors, and interference factors as the existing PT test cards. However, the new TAS PT ONE test cards were more sensitive to changes in factor activity and therefore exhibited longer clotting times in response to decreasing factor levels.

The proposed TAS PT ONE test cards are stable for two weeks at room temperature, and for at least 39 weeks at refrigerator temperatures. These studies are ongoing.

Within day precision of TAS PT test cards with various sample types

| Sample type | Cleared PT | | Proposed PT ONE | |
| --- | --- | --- | --- | --- |
| | Mean | CV (%) | Mean | CV (%) |
| citrated whole blood | 11.5 | 5.6 | 9.8 | 2.4 |
| citrated plasma | 11.9 | 3.7 | 10.6 | 1.7 |
| level I control plasma | 11.5 | 3.3 | 12.9 | 1.7 |
| level II control plasma | 19.5 | 4.3 | 29.4 | 3.6 |
| level III control plasma | 29.9 | 4.8 | 56.5 | 6.8 |

During 20 days of testing of the proposed TAS PT ONE test cards, coefficients of variation ranged from 1.8 to 4.5, and means from 11.9 to 12.8 seconds. There was no significant difference in precision of results produced with the PT ONE by multiple operators, nor between lots of test cards.

Sensitivity of PT ONE results to coagulation factor deficiencies

| Factor | Factor Level (%) Sensitivity | |
| --- | --- | --- |
| | Cleared PT | Proposed PT ONE |
| II | 20 | 20 |
| V | 35 | 35 |
| VII | 45 | 50 |
| X | 45 | 45 |

Fibrinogen levels from >15 mg/dL to 1200 mg/dL have no significant effect on PT ONE test card results; total variation in clotting time over this range was two seconds. Acidified citrate cannot be used to obtain samples for this test. Hematocrit (0-55%) has no effect on results obtained. Heparin levels above 0.75 U/ml have a slight effect. Lipid, to at least 14 mg/ml, had no effect. There was no effect of sample temperature. These characteristics are similar for the existing and proposed TAS PT test cards.

5301 DEPARTURE DRIVE, RALEIGH, NORTH CAROLINA 27604, [phone]
FAX NUMBER [phone]

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Summary of Safety and Effectiveness Information
TAS PT ONE Test card

Underfill of blood collection tubes had a greater effect on PT ONE results than did overfilling, but only tubes that were greatly underfilled produced samples that gave results outside the normal range for both test card types. Overfilling did not have a substantial effect on PT ONE results.

Clinical Performance Data: Clinical testing was done at one large hospital to establish substantial equivalence of the TAS PT ONE test cards to the TAS PT test card (the predicate device). Three hundred thirty eight blood and plasma samples drawn from 101 people (normal donors or patients undergoing warfarin therapy) were tested by the existing and proposed PT test cards on the TAS Analyzer. The correlation of test results from the PT ONE test cards and those from PT test cards had correlations of greater than 0.92 for each of several card lots tested.

The PT ONE test card was determined by CDI and by two independent testing labs to have an average ISI for blood and plasma of 1.0.

Conclusions: Sufficient information is included in this application to demonstrate that the TAS PT ONE test card, together with the TAS Analyzer, is as safe and effective as a legally marketed device (PT test cards) and that it does not raise different questions of safety and efficacy.

5301 DEPARTURE DRIVE, RALEIGH, NORTH CAROLINA 27604, [phone]
FAX NUMBER [phone]