A Novel Implantable Inferior Vena Cava Sensor: Validation of Remote Monitoring Derived Area with Computerized...

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Devices

Background:

• Intravascular volume shifts, assessed via inferior vena cava (IVC) size, correlate with adverse outcomes and hospitalizations in heart failure (HF) patients.
• Current methods for assessing volume status can be invasive or infrequent, limiting proactive management.

Purpose of the Study:

• To validate the accuracy of an implantable sensor designed for remote, daily assessment of IVC area and collapsibility index in HF patients.
• To compare sensor-derived IVC measurements against concurrent Computerized Tomography (CT) data.

Main Methods:

• A novel implantable IVC sensor was used to collect daily data on IVC area and collapsibility index.
• Sensor data was compared to CT-derived IVC area measurements in 56 patients across two global clinical studies at 3 months post-implantation.
• A validated graphical user interface (GUI) was used for CT annotation, ensuring 90% confidence and reliability.

Main Results:

• A strong correlation (r=0.99, p<0.001) was observed between sensor-derived and CT-derived IVC area.
• Excellent agreement was found, with a mean absolute error of 12.94mm² (3.35% relative error).
• Bland-Altman analysis showed a mean difference of 5.85mm² within narrow limits of agreement (-24.0 to 35.7 mm²).

Conclusions:

• The implantable IVC sensor demonstrates high accuracy in remotely assessing intravascular volume status.
• The system's robustness supports its potential clinical integration for continuous, ambulatory congestion monitoring in heart failure management.