ACIST RXi System (016616); ACIST Navvus II Catheter (016675_

K233904 · Acist Medical Systems, Inc. · DXO · Jul 17, 2024 · Cardiovascular

Device Facts

• Record ID: K233904
• Device Name: ACIST RXi System (016616); ACIST Navvus II Catheter (016675_
• Applicant: Acist Medical Systems, Inc.
• Product Code: DXO · Cardiovascular
• Decision Date: Jul 17, 2024
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 870.2870
• Device Class: Class 2

Intended Use

The ACIST RXi System is indicated for obtaining intravascular pressure measurements for use in the diagnosis and treatment of coronary and peripheral artery disease. The ACIST Navvus II MicroCatheter is intended for use with the ACIST RXi System.

Device Story

The ACIST RXi System is a catheter-based pressure monitoring system used in cath labs, interventional radiology, and ORs. It utilizes the Navvus II MicroCatheter, which contains an integrated pressure sensor, to measure distal pressure (Pd) in coronary or peripheral arteries. Proximal aortic pressure (Pa) is acquired via interface with a third-party hemodynamic system. The system console processes these inputs to calculate physiological indices, including Fractional Flow Reserve (FFR) during hyperemia and the Diastolic Pressure Ratio (dPR) during resting states. The physician operates the system via a touchscreen GUI to assess ischemic stenotic lesions. The dPR modality allows for physiologic assessment without the need for hyperemic agents, potentially reducing patient risk. Output is displayed in real-time, aiding clinical decision-making regarding the necessity of intervention.

Clinical Evidence

Bench testing only. Diagnostic performance of the dPR modality was validated using a non-clinical hemodynamic test fixture reproducing clinical waveforms from the prospective CONTRAST study. The study compared ACIST RXi dPR and Philips/Volcano iFR against FFR (cutpoint 0.80). Results: dPR accuracy 76.39% (vs iFR 78.46%), sensitivity 99.68% (vs performance goal 90%), specificity 88.92% (vs performance goal 84%). Diagnostic accuracy agreement between dPR and iFR was 93.89%.

Technological Characteristics

System includes console with embedded software, Navvus II MicroCatheter with integrated pressure sensor, and FISO signal conditioner. Operates at -30 to +300 mmHg. Pressure accuracy 3 mmHg or 3% of reading. Connectivity via TTL serial port and SPI for intra-board communication. Class II electrical isolation. Software-based calculation of FFR, Pd/Pa, and dPR indices.

Indications for Use

Indicated for patients requiring intravascular pressure measurements for diagnosis and treatment of coronary and peripheral artery disease. Contraindicated for use in cerebral vasculature.

Regulatory Classification

Identification

A catheter tip pressure transducer is a device incorporated into the distal end of a catheter. When placed in the bloodstream, its mechanical or electrical properties change in relation to changes in blood pressure. These changes are transmitted to accessory equipment for processing.

Predicate Devices

• ACIST RXi System and Navvus MicroCatheter (K190473)

Reference Devices

• Volcano s5/s5i/CORE/CORE Mobile Precision Guided Therapy System (K173860)

Submission Summary (Full Text)

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July 17, 2024

ACIST Medical Systems, Inc Bobbie Daughters Senior Regulatory Affairs Specialist 7905 Fuller Rd Eden Prairie, Minnesota 55344

Re: K233904

Trade/Device Name: ACIST RXi System; ACIST Navvus II Catheter Regulation Number: 21 CFR 870.2870 Regulation Name: Catheter Tip Pressure Transducer Regulatory Class: Class II Product Code: DXO Dated: December 11, 2023 Received: December 11, 2023

Dear Bobbie Daughters:

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

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Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30. Design controls; 21 CFR 820.90. Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products: and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

Robert T. Kazmierski -S

for

LCDR Stephen Browning Assistant Director Division of Cardiac Electrophysiology, Diagnostics, and Monitoring Devices

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Office of Cardiovascular Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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## Indications for Use

510(k) Number (if known) K233904

Device Name ACIST RXi System and Navvus II MicroCatheter

Indications for Use (Describe)

The ACIST RXi System is indicated for obtaining intravascular pressurements for use in the diagnosis and treatment of coronary and peripheral artery disease. The ACIST Navvus II MicroCatheter is intended for use with the ACIST RXi System.

| Type of Use (Select one or both, as applicable) | |
|-------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| <span></span> | <span></span> <input checked="true" type="checkbox"/> Prescription Use (Part 21 CFR 801 Subpart D) <input type="checkbox"/> Over-The-Counter Use (21 CFR 801 Subpart C) |

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Image /page/4/Picture/0 description: The image shows the text "K233904" at the top. Below this text is the logo for ACIST. The logo consists of a gray cube-like shape on the left and the word "ACIST" in blue on the right. The "®" symbol is located to the upper right of the word ACIST.

# K233904 - 510(k) Summary [21 CFR 807.92]

#### SUBMITTER

ACIST Medical Systems, Inc. 7905 Fuller Road Eden Prairie, MN 55344

Phone: [phone] Fax: [phone]

Contact Person: Bobbie Daughters, Senior Regulatory Affairs Specialist E-mail: Bobbie.Daughters(@bracco.com Alternative Contact: Katie Molland, Director, Regulatory Affairs E-mail: Katie.Molland(@bracco.com

Date Prepared: 11 December 2023

#### DEVICE

Name of Device: RXi® System and Navvus® [] MicroCatheter Common or Usual Name: Catheter tip pressure transducer Classification Name: Transducer, pressure, catheter tip (870.2870) Regulatory Class: II Product Code: DXO

#### PREDICATE DEVICE

ACIST RXi® System and Navvus® MicroCatheter (K190473)

#### REFERENCE DEVICE

The dPR index calculation algorithm software upgrade subject to this substantially equivalent to the reference device, Volcano iFR Modality in the s5"%55/CORE/CORE™ Mobile Precision Guided Therapy System cleared under K173860 on 04/11/2018 for similar intended use.

#### DEVICE DESCRIPTION

The current RXi system obtains intravascular pressure measurements for use in the diagnosis and treatment of coronary and peripheral artery disease. The RXi measures intravascular pressure in a hyperemic state following administration of adenosine as fractional flow reserve (FFR). The proposed software update for the RXi system adds a diastolic pressure ratio (dPR), which measures intravascular pressure in a non-hyperemic (resting) state. Both current and proposed ACIST RXi Systems are used in conjunction with the Navvus Catheter.

The proposed RXi System console containing embedded software that provides the main user interface. The system is used with the Navvus catheter which contains a pressure sensor for acquisition of

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pressure distal (Pd) to a lesion. The proximal aortic pressure (Pa) is acquired via an interface to a third-party hemodynamic system. The system is intended for use in catheterization and related cardiovascular specialty laboratories to compute and display fractional flow reserve (FFR) using hyperemic agents and/or nonhyperemic indices of diastolic pressure ratio (dPR) and PdPa for physiological assessment of ischemic stenotic lesions.

Measurement of FFR requires simultaneously monitoring the blood pressures proximal and distal to a lesion while inducing hyperemia. dPR is a measure of the diastolic portion of the hemodynamic waveform and can be used by the physician to perform a physiologic assessment without inducing hyperemia in the patient.

#### INDICATIONS FOR USE

The ACIST RXi® System is indicated for obtaining intravascular pressure measurements for use in the diagnosis and treatment of coronary and peripheral artery disease. The ACIST Navvus® Catheter is intended for use with the ACIST RXi System.

#### COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE

The proposed RXi System with dPR software update is substantially equivalent to the predicate RXi System (K190473). The fundamental technology and principle of operation of the RXi System are unchanged from the predicate device. The only change to the RXi System is a software updated labeling to describe the additional software features. The software update to the RXi console will allow the user to select between the existing hyperemic-induced FFR measurement and a new modality of non-hyperemic dPR measurement.

The following technological difference exists between the subject and predicate device:

Software update to allow the current system to compute and display a non-hyperemic diastolic ● pressure ratio (dPR) index for physiological assessment.

The subject device (RXi® System with dPR modality) has the same intended use, design, materials, and energy source as the legally marketed predicate device (RXi® System) cleared by FDA under premarket notification K190473. While the subject device introduces an additional technological characteristic (the dPR modality), verification and validation testing demonstrate that this technological difference does not raise of safety and effectiveness.

The identified questions of safety and efficacy apply to both the new device and the predicate. Performance testing confirmed the software update for dPR does not raise any different questions of safety and efficacy and therefore the RXi System with dPR meets substantial equivalence requirements with regards to the legally marketed predicate RXi System (K190473).

#### PERFORMANCE DATA

The risk management process has been used to evaluate the dPR software update to the RXi System in accordance with the guidelines set forth in ISO 14971:2007, Medical Devices - Application of Risk Management to Medical Devices. The risk analysis for the RXi System with dPR has taken into consideration the medical device vigilance data and product experience of the predicate RXi System. All residual risks that relate to the software update to include dPR have been taken into consideration. All RXi System and software residual risks are outweighed by potential benefits and are therefore acceptable.

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Verification and Validation testing was completed to establish the RXi system console software with dPR functionality meets specifications and performs as intended.

Software verification included unit testing, software integration, and GUI-level verification.

ACIST validated the diagnostic performance of the RXi software update to introduce the dPR modality by demonstrating the agreement between the non-hyperemic RXi dPR index and the non-hyperemic instantaneous wave-free ratio (iFR) modality of the FDA-cleared reference device, Volcano s5/s5i CORE Mobile (K173860) as compared to FFR using a dataset collected in a prospective clinical study.

The diagnostic performance evaluation used a non-clinical bench top hemodynamic test fixture to reproduce resting and hyperemic clinical waveform recordings from the prospective CONTRAST clinical study. Resting and hyperemic pressure readings from each recorded waveform were measured using the ACIST RXi System and Navvus Catheter, and in parallel, the Philips Verrata PLUS wire and Philips (Volcano) CORE Mobile system. A statistical analysis of the collected datasets demonstrated all three pre-determined primary endpoints (diagnostic accuracy, sensitivity, and specificity) were met.

Compared to FFR measurements (cutpoint 0.80), the accuracy of dPR (cutpoint 0.89) was 76.39%, and the accuracy of iFR (cutpoint 0.89) was 78.46%, resulting in a diagnostic accuracy difference of -2.08%. The sensitivity for dPR vs iFR was 99.68% and was higher than the pre-determined performance goal of 90%. The specificity for dPR vs iFR was 88.92% and was higher than the pre-determined performance goal of 84%. The diagnostic accuracy of dPR compared to iFR was 93.89%, confirming the agreement of diagnostic accuracy between dPR and iFR compared to FFR and supporting a conclusion of substantial equivalence.

#### CONCLUSIONS

The results from the tests mentioned above demonstrate that the technological and performance characteristics of the proposed RXi System are comparable to the predicate device. The results of testing and outputs of the risk management process support the safety and effectiveness of the dPR software upgrade and ensure the subject device can perform in a manner equivalent to the predicate device with the same intended use. The results of the verification/validation tests and the risk analysis have demonstrated that the software upgrade to allow calculation of dPR does not add any new questions of safety and is therefore substantially equivalent to the predicate RXi System (K190473) and reference device, Volcano iFR Modality (K173860).

### SUBSTANTIAL EQUIVALENCE

The new proposed device is the RXi System including a new dPR modality. The predicate device is the currently marketed RXi System without a dPR modality (K190473). The Navvus Catheter and accessories included in K190743 are not affected by this submission. The only change to the RXi System is to add a nonhyperemic diastolic pressure ratio (dPR) calculation for added functionality in the software capabilities and updated labeling to describe the additional software features. The reference device is the marketed Volcano s5 system (K173860), specifically the iFR modality. The purpose of the reference device iFR modality is to demonstrate safety and effectiveness of the dPR modality.

Equivalence of Intended Use:

¹ Johnson NP, Jeremias A, Zimmermann FM, et al. Continuum of vasodilator stress from rest to contrast medium to adenosine hyperemia for fractional flow reserve assessment. JACC: Cardiovascular Interventions. 2016;9(8):757-767

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Indications for the device remain unchanged from the predicate device. The reference device contains similar indications for the pressure measurement modality.

#### Equivalence of Technological Characteristics:

The only difference between the subject and predicate devices is the addition of the dPR modality embedded into the software of the RXi System. Otherwise, the subject and predicate device share identical technological characteristics. Performance testing has confirmed the equivalent diagnostic performance of the subject device dPR modality relative to the iFR modality of the reference device.

No new questions of safety and effectiveness were identified during review of Risk Management documentation or execution of Verification and Validation activities.

#### Safety and Effectiveness:

The identified questions of safety and efficacy apply to both the new device and the predicate; therefore, the new device does not raise different questions of safety and efficacy. Specifically, a resting index calculation poses less risk to the patient as there is no need to use a hyperemic agent. The proposed device does not raise any different questions of safety and efficacy.

#### Conclusion:

The proposed device, RXi System with dPR software upgrade, was shown to be substantially equivalent to the legally marketed predicate RXi System (K190473), except for a software change introducing the dPR modality.

The safety and effectiveness of the RXi System dPR modality has been shown to be substantially equivalent to the iFR modality of marketed device K173860.

| Feature | Proposed Device –<br>RXi System | Predicate Device –<br>RXi System | Reference Device –<br>Volcano iFR | |
|-----------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------|
| Regulatory Information | Name | RXi System | RXi System | Volcano<br>s5/s5i/CORE/CORE<br>Mobile Precision Guided<br>Therapy System |
| | 510(k)# | Not yet assigned | K190473 | K173860 |
| | Predicates | K190473 | K132474 | K133323<br>K170133 |
| | Classification Name | Catheter, pressure<br>monitoring, cardiac | Catheter, pressure<br>monitoring, cardiac | Ultrasonic Pulsed Echo<br>Imaging System |
| | Product Code &<br>Regulation Number | DXO, OBI<br>21 CFR 870.2870,<br>21 CFR 870.1200 | OBI, DXO<br>21 CFR 870.1200,<br>21 CFR 870.2870 | IYO<br>21 CFR 892.1560 |
| | FDA Classification | II | II | II |
| | Classification Panel | Cardiovascular | Cardiovascular | Radiology |
| Feature | Proposed Device –<br>RXi System | Predicate Device –<br>RXi System | Reference Device –<br>Volcano iFR | |
| | Indications for Use/<br>Intended Use | The ACIST RXi System is<br>indicated for obtaining<br>intravascular pressure<br>measurements for use in the<br>diagnosis and treatment of<br>coronary and peripheral<br>artery disease. The ACIST<br>Navvus Catheter is intended<br>for use with the ACIST RXi<br>System. | The ACIST RXi System is<br>indicated for obtaining<br>intravascular pressure<br>measurements for use in<br>the diagnosis and treatment<br>of coronary and peripheral<br>artery disease. The ACIST<br>Navvus Catheter is<br>intended for use with the<br>ACIST RXi System. | |
| Contraindications | The ACIST Navvus<br>Catheter is contraindicated<br>for use in the cerebral<br>vasculature. | The ACIST Navvus<br>Catheter is contraindicated<br>for use in the cerebral<br>vasculature. | Use of the Volcano<br>system is contraindicated<br>wherever tissue or organ<br>damage is a reasonable<br>probability.<br>The catheter is not for<br>fetal use. | |
| Feature | | Proposed Device –<br>RXi System | Predicate Device –<br>RXi System | Reference Device –<br>Volcano iFR |
| Technological Characteristics | Fundamental<br>Scientific<br>Technology | A device with an integrated<br>pressure sensor used in the<br>real-time calculation of FFR<br>or dPR based on patient<br>blood pressure | A device with an integrated<br>pressure sensor used in the<br>real-time calculation of<br>FFR based on patient blood<br>pressure | A device with an<br>integrated pressure sensor<br>used in the real-time<br>calculation of FFR or dPR<br>based on patient blood<br>pressure |
| | Prescription Use | Rx Only | Rx Only | Rx Only |
| | System<br>Components and<br>accessories | Console with embedded<br>software, Navvus Catheter<br>connection port, FISO<br>signal conditioner,<br>touchscreen, and graphical<br>user interface (GUI), and<br>accessories (mount, cart,<br>hemodynamic cables, power<br>supply and cord, AO<br>interface box) | Console with embedded<br>software, Navvus Catheter<br>connection port, FISO<br>signal conditioner,<br>touchscreen, and graphical<br>user interface (GUI), and<br>accessories (mount, cart,<br>hemodynamic cables,<br>power supply and cord, AO<br>interface box) | This reference device is a<br>larger system with<br>additional capabilities not<br>related to this submission. |
| | Pressure Sensing<br>and Signal<br>Transmission<br>Technology | EEPROM in the Navvus<br>Catheter connector<br>communicates with the<br>FISO board in the RXi<br>Console | EEPROM in the Navvus<br>Catheter connector<br>communicates with the<br>FISO board in the RXi<br>Console | Pressure measurement is<br>captured through the use<br>of pressure wires. |
| | Connected<br>Device(s) | Navvus/Navvus II Catheter | Navvus/Navvus II Catheter | SmartWire II, PrimeWire<br>Prestige,<br>Prime Wire<br>Prestige Plus, Verrata,<br>Verrata Plus |
| | Auto-Zeroing | Yes | Yes | Yes |
| | Diastolic Resting<br>Indices | dPR, Pd/Pa | Pd/Pa | iFR |
| | User Interface<br>Displays | • Audible and visual<br>alarm<br>• LED Status<br>Indicators<br>• Console<br>touchscreen | • Audible and visual<br>alarm<br>• LED Status<br>Indicators<br>• Console<br>touchscreen | • Bedside:<br>Touchpad or joystick<br>• Control room:<br>Console |
| | Intended Operating<br>Environment | • Angiographic<br>Catheterization Lab<br>• Interventional<br>Radiology Lab<br>• Operating Room<br>(OR) | • Angiographic<br>Catheterization Lab<br>• Interventional<br>Radiology Lab<br>• Operating Room<br>(OR) | • Angiographic<br>Catheterization Lab<br>• Interventional<br>Radiology Lab<br>• Operating Room<br>(OR) |
| | Electrical Isolation<br>(UL Classification) | Class II (double isolation) | Class II (double isolation) | Class I (functional<br>ground) |
| | Operating Pressure | -30 to +300 mmHg | -30 to +300 mmHg | -30 to 300 mmHg |
| Feature | Proposed Device -<br>RXi System | Predicate Device -<br>RXi System | Reference Device -<br>Volcano iFR | |
| Zero Drift | < 7 mmHg over one hour | < 7 mmHg over one hour | 5 mmHg / 10 minutes | |
| Pressure Accuracy | 3 mmHg or 3% of reading | 3 mmHg or 3% of reading | Not Specified | |
| Calculation types/<br>Physiological<br>Measurements | FFR, Pd/Pa and dPR | FFR and Pd/Pa | FFR, iFR | |
| Hyperemic agent | Not required for dPR<br>Required for FFR | Required for FFR | Not required for iFR<br>Required for FFR | |
| Resting Indices<br>Wave Selection | Automatically selected | N/A | Automatically selected | |
| Resting Indices<br>Cutoff Point | 0.89 | N/A | 0.89 | |
| Aortic Input | 100 mmHg/V | 100 mmHg/V | High Level (100 mm<br>Hg/V) | |
| Distal Pressure<br>Output | 5μV/V/mmHg | 5μV/V/mmHg | Low Level 5 uV/mmHg | |
| Software<br>Application | Microsoft Windows CE<br>Real-Time Operating<br>System RTOS | Microsoft Windows CE<br>Real-Time Operating<br>System RTOS | Not specified | |
| Signal Acquisition | 8 milliseconds | 8 milliseconds | Not specified | |
| Real-Time Clock<br>and Battery | Console software contains a<br>real-time clock and battery<br>back-up | Console software contains<br>a real-time clock and<br>battery back-up | Not specified | |
| Communication<br>Protocols | Serial Peripheral Interface<br>(SPI) is used for intra-board<br>communications within the<br>RXi Console, TTL serial<br>port between FISO signal<br>conditioner and RXi console | Serial Peripheral Interface<br>(SPI) is used for intra-<br>board communications<br>within the RXi Console,<br>TTL serial port between<br>FISO signal conditioner<br>and RXi console | Not specified | |

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