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The Edwards Lifesciences Acumen Hypotension Prediction Index feature provides the clinician with physiological insight into a patient's likelihood of future hypotensive events (defined as mean arterial pressure < 65 mmHg for at least one minute in duration) and the associated hemodynamics. The Acumen HPI feature is intended for use in surgical or nonsurgical patients receiving advanced hemodynamic monitoring. The Acumen HPI feature is considered to be additional quantitative information regarding the patient's physiological condition for reference only and no therapeutic decisions should be made based solely on the Hypotension Prediction Index (HPI) parameter.

The Acumen Hypotension Prediction Index feature consists of software running on the Edwards Lifesciences HemoSphere Advanced Monitoring Platform paired with the Acumen IQ extravascular blood pressure transducer (K152980) and a peripheral arterial catheter. The monitoring system includes the Acumen Hypotension Prediction Index (HPI), and graphical user interface features displaying hemodynamic parameters relevant to assessing the root cause of a potential hypotensive event. The Acumen Hypotension Prediction Index is an index related to the likelihood of a patient experiencing hemodynamic instability defined as a hypotensive event* within 15 minutes, where zero (0) indicates low likelihood and one hundred (100) indicates a hypotensive event is occurring. The Acumen Hypotension Prediction Index parameter (HPI), should not be used exclusively to treat patients. A review of the patient's hemodynamics is recommended prior to initiating treatment. * A hypotensive event is defined as mean arterial pressure (MAP) < 65 mmHg for one minute in duration

Here is the extracted information regarding the acceptance criteria and the study that proves the device meets them:

1. A table of acceptance criteria and the reported device performance

Study Proving Device Meets Acceptance Criteria:

The study proving the device meets the acceptance criteria is titled:
"A Prospective, Single-Arm, Open-Label, Multicenter Study of the Hypotension Prevention and Treatment in Patients Receiving Arterial Pressure Monitoring with Acumen Hypotension Prediction Index Feature (HPI Study)."

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

• Test Set (HPI Study):

  • Sample Size: 485 eligible Subjects (460 pivotal with an additional 25 roll-in cases). The Full Analysis Set (FAS) for primary effectiveness included 406 subjects.
  • Data Provenance:
    • Country of Origin: United States (11 study sites).
    • Nature: Prospective, single-arm, unblinded study.

• Comparison Group (Historical Control):

  • Sample Size: 22,109 patients. The population for the primary effectiveness comparison that experienced IOH was 19,445 subjects.
  • Data Provenance:
    • Country of Origin: United States (from hospitals across the United States).
    • Nature: Retrospective historical control group from the Multicenter Perioperative Outcomes Group (MPOG) academic consortium. Dates of data treatment were between January 1, 2017, and December 31, 2017.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

The document does not explicitly state the number of experts or their qualifications for establishing the ground truth related to the MPOG historical control data or the real-time monitoring data from the HPI Study.

However, the "ground truth" for hypotension (MAP < 65 mmHg for at least one minute) is a directly measurable physiological parameter captured by arterial pressure monitoring, which is a standard of care. The definition of IOH (MAP < 65 mmHg for three or more consecutive 20-second events) is based on established clinical understanding and recorded data rather than expert adjudication of an image or subjective finding.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

The document does not mention an adjudication method (like 2+1 or 3+1) for establishing the ground truth or evaluating the outcomes in the HPI study. The primary outcome (duration of IOH) and secondary outcomes (AUC, adverse events) were based on directly measured physiological data (MAP) and recorded clinical events, rather than subjective interpretations requiring multiple expert adjudicators. Serious adverse events (SAEs) were "adjudicated," but the specifics of this adjudication process (e.g., number of adjudicators, their roles) are not detailed.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

A multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly stated or described as typically understood in the context of image interpretation or diagnostic performance comparison between human readers and AI.

Instead, the study investigated the effectiveness of the Acumen HPI Feature as a decision support tool for clinicians in reducing the duration of IOH. This is a comparative effectiveness study comparing a cohort where clinicians had access to the HPI feature's guidance (HPI Study arm) versus a historical control cohort where clinicians did not have this specific AI-driven predictive guidance (MPOG).

The "effect size" can be considered as the 57.6% reduction in mean IOH duration observed in the HPI arm compared to the MPOG historical control, and a 65% reduction when considering instances with zero IOH episodes. This indicates a significant improvement in patient outcomes (reduced IOH) when clinicians utilize the Acumen HPI Feature for guidance.

6. If a standalone (i.e. algorithm only, without human-in-the-loop performance) was done

The document describes the Acumen HPI Feature as a "decision support tool" providing "physiological insight" and "guidance" for clinicians. The primary effectiveness endpoint specifically evaluates the use of the Acumen HPI Feature to guide intraoperative hemodynamic management. This indicates that the study assessed human-in-the-loop performance, where clinicians were receiving and acting upon the device's output. There is no mention of a standalone algorithm-only performance study.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

The ground truth used for effectiveness endpoints was physiological measures and clinical outcomes data:

• Intraoperative Hypotension (IOH): Defined as Mean Arterial Pressure (MAP) < 65 mmHg for at least one minute (for the general definition) or for three or more consecutive 20-second events (for the study's specific IOH episode definition), which is directly measurable physiological data from arterial pressure monitoring.
• Area Under the Curve (AUC): Calculated from MAP values below 65 mmHg over time.
• Adverse Events/Complications: Such as cardiac arrest, death, stroke, AKI, and MINS, which are clinical outcomes recorded from patient data.

8. The sample size for the training set

The document does not specify the sample size or details of a training set for the Acumen Hypotension Prediction Index feature algorithm. It mentions that the "Acumen Hypotension Prediction Index (HPI parameter) algorithm as implemented on the HemoSphere Advanced Monitoring Platform (K201446, October 1, 2020) is identical to Acumen Hypotension Prediction Index (HPI parameter) algorithm granted in DEN160044." This suggests the algorithm itself was developed and cleared previously, and the current submission focuses on additional clinical data and labeling modifications.

9. How the ground truth for the training set was established

Since the document does not provide details of a training set for this specific submission, it also does not describe how the ground truth for any training set might have been established. Based on the nature of the device (predicting hypotension), it is highly likely that any prior training would have used large datasets of continuous arterial pressure waveforms and corresponding MAP values as ground truth for hypotensive events, similar to the definition used in the clinical study.

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