False-Positive PET Uptake in Left Atrial Appendage Closure Devices Due to Postoperative Inflammatory Response.

Area of Science:

• Cardiovascular Imaging
• Nuclear Medicine
• Medical Devices

Background:

• Positron emission tomography (PET) is crucial for diagnosing cardiovascular infections.
• Non-infectious inflammatory processes can cause false-positive PET results.
• Left atrial appendage closure devices (LAACD) present a diagnostic challenge due to potential radiotracer uptake.

Purpose of the Study:

• To analyze radiotracer uptake in LAACDs (AtriClip®).
• To determine if uptake is associated with infectious or inflammatory processes.
• To prevent misinterpretation of PET/CT scans for cardiovascular infections.

Main Methods:

• Retrospective analysis of 28 PET/CT scans (20 patients) with implanted LAACDs.
• Utilized 18F-fluorodeoxyglucose (FDG) and 18F-Choline (CHO) radiotracers.
• Reviewed clinical, laboratory, and imaging data with long-term follow-up for infection.

Main Results:

• Homogeneous PET uptake in LAACDs observed in 93% of studies, irrespective of tracer or time since implantation.
• No evidence of device-related infection found in any patient.
• No significant difference in SUV ratios across PET indication groups or in patients with/without other infections.

Conclusions:

• FDG and CHO uptake in LAACDs is a consistent finding.
• Uptake likely represents sterile, postoperative inflammatory response, not true infection.
• Recognizing this pattern is vital to avoid false-positive PET/CT results in cardiovascular infection evaluations.