(219 days)
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.
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 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.
The provided text describes the ACIST RXi System and Navvus II MicroCatheter, with a focus on a software update to include a diastolic pressure ratio (dPR) modality. The information primarily relates to the substantial equivalence determination for this medical device, rather than a clinical study evaluating an AI device's performance against human readers. Therefore, many of the requested points, particularly those pertaining to AI device performance evaluation criteria (e.g., sample size for test set, number of experts, adjudication method, MRMC study, training set details), are not present in the provided document.
However, I can extract information related to the device's performance and the study that demonstrated its substantial equivalence.
Here's a summary of the available information based on the provided text, addressing your points where possible and noting where information is not available:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the dPR functionality were primarily based on demonstrating agreement with an FDA-cleared reference device (Volcano iFR Modality) when compared to FFR measurements.
| Acceptance Criteria (Performance Goals) vs. Reference iFR compared to FFR | Reported Device Performance (RXi dPR compared to FFR, and dPR vs iFR) |
|---|---|
| Diagnostic accuracy: Not explicitly stated as a goal for dPR vs FFR, but indirectly implied by seeking agreement with iFR. | Accuracy of dPR (cutpoint 0.89) vs. FFR (cutpoint 0.80): 76.39% |
| Sensitivity: Pre-determined performance goal of 90% (for dPR vs iFR comparison) | Sensitivity for dPR vs iFR: 99.68% (Higher than pre-determined goal) |
| Specificity: Pre-determined performance goal of 84% (for dPR vs iFR comparison) | Specificity for dPR vs iFR: 88.92% (Higher than pre-determined goal) |
| Agreement of diagnostic accuracy between dPR and iFR compared to FFR. | Diagnostic accuracy of dPR compared to iFR: 93.89% (This confirms the agreement, supporting substantial equivalence) |
| Zero Drift: |
§ 870.2870 Catheter tip pressure transducer.
(a)
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.(b)
Classification. Class II (performance standards).