Nuclear imaging in cardiac amyloidosis

Area of Science:

• Nuclear Medicine
• Cardiology
• Amyloidosis Research

Background:

• Amyloidosis involves amyloid protein deposition in organs, potentially causing severe cardiac dysfunction.
• Cardiac amyloidosis can lead to arrhythmias, heart failure, and sudden cardiac death.
• Accurate diagnosis and monitoring of cardiac amyloidosis are crucial for patient outcomes.

Purpose of the Study:

• To review nuclear imaging modalities for visualizing myocardial amyloid involvement.
• To evaluate the effectiveness and mechanisms of various SPECT and PET tracers.
• To identify the most promising imaging techniques for cardiac amyloidosis.

Main Methods:

• Systematic review of PubMed/Medline literature on nuclear imaging for cardiac amyloidosis.
• Analysis of SPECT tracers, including Iodine-123 MIBG ([(123)I]mIBG), Technetium-99m aprotinin, and Technetium-99m phosphate derivatives.
• Consideration of Positron Emission Tomography (PET) tracers.

Main Results:

• [(123)I]mIBG demonstrates significant clinical evidence, correlating MIBG activity defects with impaired cardiac sympathetic nerve endings due to amyloid deposits.
• [(123)I]mIBG offers objective evaluation of cardiac sympathetic function, indirectly measuring amyloid infiltration.
• [(99m)Tc]Tc-aprotinin and [(99m)Tc]-labeled phosphate derivatives are less sensitive options, potentially useful for differential diagnosis.

Conclusions:

• [(123)I]mIBG is a valuable tool for assessing cardiac sympathetic denervation in amyloidosis.
• Further research is needed for PET tracers, despite their advantages in quantification and resolution, for cardiac amyloidosis studies.